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Conference 13093
Space Telescopes and Instrumentation 2024: Ultraviolet to Gamma Ray
16 - 21 June 2024
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Session 1:
Ultra Violet I
16 June 2024 • 08:30 - 09:50 Japan Standard Time
Session Chair:
Yoichi Yatsu, Tokyo Institute of Technology (Japan)
13093-1
16 June 2024 • 08:30 - 08:50 Japan Standard Time
Show Abstract +
Aspera is a NASA-funded UV SmallSat Pioneers mission designed to detect and map warm-hot phase halo gas around nearby galaxies. The Aspera payload is designed to detect faint diffuse O VI emission at around 103.2 nm, satisfying the sensitivity requirement of 5E-19 erg/s/cm^2/arcsec^2 over 179 hours of exposure. In this presentation, we describe the overall payload design. The payload comprises two identical co-aligned UV long-slit spectrograph optical channels sharing a common UV-sensitive Micro Channel Plate detector. The design delivers spectral resolution R ~ 2,000 over the wavelength range of 101 to 106 nm. The field of view of each channel is 1 degree by 30 arcsec, with an effective area of 1.1 cm^2. The mission is now entering Phase D, payload integration, and testing, with the projected launch-ready date set for late-2025. The mission will be launched into low-Earth orbit via rideshare.
13093-2
16 June 2024 • 08:50 - 09:10 Japan Standard Time
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The Faint Intergalactic Medium Redshifted Emission Balloon (FIREBall-2) is a UV multi-object spectrograph designed to detect emission from the circumgalactic and circumquasar medium at low redshifts (0.3 < z < 1.0). The FIREBall-2 spectrograph uses a suborbital balloon vehicle to access a stratospheric transmission window centered around 205 nm and is fed by a 1-m primary parabolic mirror and a 2-mirror field corrector that allows an ≈11’ x 35’ field of view. The slit-mask spectrograph can access dozens of galaxy targets per field, with each target spectrum read out on a UV electron-multiplying CCD detector. Following a flight in 2018, several refurbishments and modifications were made to the instrument and telescope to prepare for additional flight opportunities. Here we present an overview of upgrades and improvements made since the previous flight and discuss the 2023 field campaign, which culminated in a flight from Fort Sumner, New Mexico in September, 2023.
13093-3
16 June 2024 • 09:10 - 09:30 Japan Standard Time
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The Star-Planet Activity Research CubeSat (SPARCS) is 6U CubeSat whose mission will be to observe low-mass stars in two ultraviolet (UV) bands. SPARCS will provide time-dependent spectral slope, intensity, and evolution of stellar radiation with the goal of understanding the short and long term variability of these targets.
Here we will summarize the performance of SPARCam, the science camera for SPARCS. SPARCam is a two-detector camera system allowing independent commanding of two delta-doped, UV CCD47-20 detectors, separately optimized for the SPARCS near-UV (NUV; 260–300 nm) and far-UV (FUV; 153–171 nm) bands. The presentation will include a description of the camera electronics as well as an in-depth characterization of the UV detectors.
SPARCam was designed and built by the Jet Propulsion Laboratory and delivered to Arizona State University in October 2023.
13093-4
16 June 2024 • 09:30 - 09:50 Japan Standard Time
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We present the results of the JUpiter ICy moons Explorer ultraviolet spectrograph (JUICE-UVS) near-earth commissioning. Near-earth commissioning activities included measurements of detector dark noise, optimizing detector HV level via observations of the interplanetary Lyman-alpha, and a “sky-spin” observation over the JUICE-UVS 7.5°-long slit while the spacecraft rolled about the high-gain antenna. Dark rates matched those measured on the ground. HV levels were nominal for the operational temperature. Observations with the high-spatial resolution aperture confirmed the sharpened focus when compared to nominal observations. The “sky-spin” observation passed through the galactic plane, observing many known UV-bright stars. These stars provide a rough estimate of instrument effective area that will be refined after JUICE passes >2 AU from the sun, enabling 3-axis stabilized pointed observations.
Break
Coffee Break 09:50 - 10:10
Session 2:
Ultra Violet II
16 June 2024 • 10:10 - 11:50 Japan Standard Time
Session Chair:
Walter M. Harris, The Univ. of Arizona (United States)
13093-5
16 June 2024 • 10:10 - 10:30 Japan Standard Time
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We present a spacecraft and payload system design of a UV space telescope on a ∼130kg micro-satellite mission with a moderately fast repointing capability and near real-time alert communication. The mission, called Quick Ultra-Violet Kilonova surveyor – QUVIK, shall measure the brightness evolution of kilonovae, resulting from mergers of neutron stars simultaneously in the near-UV and far-UV band and thus it shall distinguish between different explosion scenarios. As a secondary objective the mission will also provide unique follow-up capabilities for other transients both in the near- and far-UV bands. The mission was selected for implementation by an ambitious Czech national mission program to promote the development of Czech science and space technology.
13093-6
16 June 2024 • 10:30 - 10:50 Japan Standard Time
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The Integral Field Ultraviolet Spectrographic Experiment (INFUSE) sounding rocket is the first far-ultraviolet integral field spectrometer. The first launch of INFUSE occurred from White Sands Missile Range on October 29th, 2023, and demonstrated spectral multiplexing, successfully detecting ionized gas emission in the XA region of the Cygnus loop. The second launch of INFUSE is projected for spring 2025 to observe the star-forming galaxy NGC 2366 alongside companion NGC 2363. Several enhancements are planned for INFUSE before this second science flight, including adding an improved baffle to reduce contamination by second order light and treating several surfaces to reduce scattered geocoronal Lyman alpha. An additional grating will also be added to flight-qualify a new coating of Xenon enhanced Lithium Fluoride. We report on the flight results from the first launch as well as outline progress towards preparation for the second flight.
13093-7
16 June 2024 • 10:50 - 11:10 Japan Standard Time
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The Spatial Heterodyne Extreme Ultra-Violet Interferometer (SHEUVI) is an instrument developed through the NASA PICASSO program. We present experimental results from the SHEUVI instrument; provide a brief overview and the historical evolution of ARSHS; describe how precipitous results from the SHEUVI effort inspired the instrument design for the recently selected NASA - Astrophysics Research and Analysis (APRA) VUV rocket program; and, discuss how this project has also influenced current design work for future SmallSat/CubeSat mission opportunities.
13093-8
16 June 2024 • 11:10 - 11:30 Japan Standard Time
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PETREL (Platform for Extra & Terrestrial Remote Examination with LCTF) is a 50kg class satellite with a 80mm-diameter Ultraviolet Telescope (UVT). The science missions of the UVT system are the discovery of high-energy transients, such as supernovae and gravitational-wave electromagnetic sources. To achieve them, the optical system is optimized to detect near-UV photons between 250 and 300 nm. Within a 30-minutes exposure time per every revolution, it surveys a remarkably wide field as 50 deg^2 with a high sensitivity of 20~ AB magnitude. The Board Unit has an on-board computer, which directly analyzes raw images obtained by a back-illuminated CMOS sensor. The computer can detect transients immediately, so as to alert the transient information to ground within 30 minutes of discovery. We will achieve the first UV survey to explore the transients in their early phase and reveal the underlying physical processes.
13093-9
16 June 2024 • 11:30 - 11:50 Japan Standard Time
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Aspera is a NASA Astrophysics Pioneers SmallSat mission designed to study diffuse OVI emission from the warm-hot phase gas in the halos of nearby galaxies. Its payload consists of two identical Rowland Circle type long-slit spectrographs, sharing a single MicroChannel plate (MCP) detector. Each spectrograph channel, consisting of an off-axis parabola (OAP) primary mirror and a toroidal diffraction grating optimized for the 103-104 nm bandpass. Despite the simple configuration, the optical challenging alignment/integration process for Aspera is challenging due to tight optical tolerances, driven by the compact form factor, and the contamination sensitivity of the Far-Ultraviolet optics and detectors. In this paper, we discuss implementing a novel multi-phase approach to meet these requirements using state of the art optical metrology tools. For coarsely positioning the optics we use a blue-laser 3D scanner while the fine-alignment is done with Zygo interferometer and a custom computer generated hologram. The detector focus requires iterative in-vacuum alignment using Vacuum UV collimator. The alignment is done in a controller cleanroom facility at the University of Arizona.
Break
Lunch Break 11:50 - 13:10
Session 3:
Ultra Violet III
16 June 2024 • 13:10 - 15:10 Japan Standard Time
Session Chair:
Sarah E. Tuttle, Univ. of Washington (United States)
13093-10
16 June 2024 • 13:10 - 13:30 Japan Standard Time
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The MANTIS (Monitoring Activity of Nearby sTars with uv Imaging and Spectroscopy) 16U CubeSat mission, led by the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado Boulder, plans to characterize the high-energy stellar radiation that drives atmospheric photochemistry and escape on extrasolar planets by conducting simultaneous observations of exoplanet host stars at extreme-ultraviolet (100–1200A; EUV), far-ultraviolet (1300–2200A; FUV), near-ultraviolet (2200–3500A; NUV), and visible (3500–10000A; VIS) wavelengths. The science payload's two-telescope design enables simultaneous coverage over the entire UV passband and the first EUV astrophysics capability in over 20 years. An 8.5cm diameter grazing incidence telescope feeds a low-resolution EUV spectrograph while a 14x9cm rectangular Cassegrain telescope feeds a dichroic beamsplitter to divide the light into both an NUV/VIS and FUV channel. The MANTIS design, detector systems, spacecraft bus and mission operations build off of the heritage of the CUTE and SPRITE CubeSats developed by the MANTIS team. This proceeding overviews the design of the MANTIS instrument and general mission concept.
13093-11
16 June 2024 • 13:30 - 13:50 Japan Standard Time
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Eos is a mission concept to be proposed to the expected 2025 NASA Small Explorers Announcement of Opportunity. Eos observes molecular clouds in our galaxy and nearby planet forming disks to understand the link between star and planet formation and molecular hydrogen in galactic star forming regions. Eos does this using very long-slit, moderate resolution spectroscopy of UV emission from fluorescent molecular hydrogen, a powerful and underutilized FUV diagnostic. H2 is the most abundant molecule in the universe, but is typically observed in the IR or observed via proxies such as CO. Eos will directly observe H2 via fluorescence, which can be stimulated from a range of sources (shocks, external energy fields, bright stars, etc). Here we briefly describe the science objectives of Eos, as well as the instrument implementation.
13093-12
16 June 2024 • 13:50 - 14:10 Japan Standard Time
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What is the amount of ionizing energy incident on exoplanet atmospheres from their host stars? What is the relationship between white-light flares and this ionizing energy? These are key questions required to link our current archive of hundreds of stellar whitelight flares to the ionizing radiation released during them, and the ramifications of those flares on the survival of exoplanetary atmospheres, particularly for planets orbiting within the habitable zones of low-mass stars. The Small NASA Optical Ultraviolet Telescope (SNOUT) is a proposed Pioneers mission comprised of two co-pointing telescopes: one optimized for EUV wavelengths (comprised of three separate EUV segments) and one for visible wavelengths. SNOUT is designed to measure the quiescent extreme-UV (EUV) emission for 30 mow-mass stars (0.3 - 1 solar masses), covering a range of ages, in three EUV bandpasses. The combined instrument is housed in an ESPA-Grande spacecraft and will launch into low Earth orbit for a one-year baseline mission. SNOUT has a substantial educational and early-career mentoring component; early-career scientists and engineers comprise more than half of the team, including key leadership roles.
13093-13
16 June 2024 • 14:10 - 14:30 Japan Standard Time
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The Polstar SMEX mission has been designed to study the impact of rotation and environment on the evolution of massive stars. These stars are the most important contributors to galactic cosmic evolution, as they live out their entire lives and go supernova while low-mass stars are still forming. Massive stars drive the ecology of star formation through the Baryonic Cycle. A host of theories predict profound, yet different, consequences on stellar evolution for rapid rotation in these stars, so observational constraints are now essential. Polstar will use UV spectropolarimetry to capitalize on tell-tale stellar and wind asphericities induced by rapid rotation, to constrain the internal physics that dictates the evolution of the star and its impact on the Galaxy. Polstar will deliver 0.01% UV spectropolarimetry to provide a new window, a new capability to view the Universe with.
Show Abstract +
The Ultraviolet Explorer (UVEX) mission is built on three scientific pillars: (I) Exploring the low-mass, low-metallicity galaxy frontier; (II) Providing new views of the dynamic universe, and (III) Leaving a broad legacy of modern, deep synoptic surveys. The deep, synoptic all-sky survey includes the Galactic Plane and Magellanic Clouds and achieves depths and resolution matching modern optical/IR surveys with Rubin, Roman, and Euclid. UVEX will follow up the aftermath of GW-detected NS mergers and provide the first rapid UV spectroscopic follow-up of transients. The UVEX payload consists of a single instrument with simultaneous FUV and NUV imaging over a wide (12 deg2) FOV and sensitive R>1000 spectroscopy over a broad band from 1150 – 2650 Å. Placed in a highly elliptical, TESS-like orbit, UVEX achieves low background and high observing efficiency. Frequent ground contacts and rapid slew capability enable UVEX to promptly follow up targets of opportunity, providing the first rapid, deep UV imaging and spectroscopic follow-up capability.
13093-15
16 June 2024 • 14:50 - 15:10 Japan Standard Time
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PETREL's science goal is to detect transient phenomena in ultraviolet objects and to reveal the nature of explosive phenomena in the universe through multi-messenger observations. PETREL is equipped with an 8cm refractor telescope and a COTS BI-CMOS detector behind an optical blind filter. Expected sensitivity is 20 mag(AB) for a 50 deg^2 field of view at a wavelength of 250-300 nm with a 30 minute exposure. To perform multi-messenger observations, the high-performance OBC automatically analyzes the acquired images and searches for transient sources on board. The coordinates and magnitudes of transients are transmitted to the ground within minutes via a commercial real-time communication network. The overall system of the PETREL satellite, with a particular focus on ultraviolet astronomy missions, will be presented.
Break
Coffee Break 15:10 - 15:40
Session 4:
Ultra Violet IV
16 June 2024 • 15:40 - 17:20 Japan Standard Time
Session Chair:
Shouleh Nikzad, Jet Propulsion Lab. (United States)
13093-16
16 June 2024 • 15:40 - 16:00 Japan Standard Time
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We present the experimental design of Maratus, a proposed 6U cubesat designed to map the circumgalactic medium of nearby galaxies. We leverage recent work in absorption line measurements of the gas near galaxies, improved far ultraviolet optical component performance, and the flexibility of the cubesat platform to create a pathfinding experiment at relatively low cost.
We outline the key motivations behind such a mission, present the technical approach and feasibility measures, and conclude by highlighting the role Maratus can play in supporting upcoming larger scale missions, such as the Habitable Worlds Observatory.
13093-17
16 June 2024 • 16:00 - 16:20 Japan Standard Time
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Type Ia supernovae (SNe Ia) are a cornerstone of modern cosmology. Upcoming missions like the Nancy Grace Roman Telescope are pushing to high redshifts to measure cosmological parameters like the dark energy equation of state. Despite the impressive success of empirically standardizing their luminosities, the explosion mechanism of SNe Ia remains hotly debated; e.g., the mass of the white dwarf (WD) when it explodes and the state of the companion star (degenerate or non-degenerate) are all currently in question.
Early-time UV observations are sensitive to the outermost layers of the ejecta (and least affected by the explosion itself) and show the most diversity for SNe Ia. This makes the UV bandpass an excellent probe to solve these open questions about the nature of these cosmological distance indicators. To achieve this science, we present UVIa, a CubeSat that will be reactive and have simultaneous optical, Near-UV (NUV), and Far-UV (FUV) coverage, takes advantage of state-of-the-art UV coatings, UV-enhanced silicon detectors with whitelight rejection filter, and autonomous observing scheduling, updated regularly based on newly discovered SNe Ia from modern transient surveys.
13093-18
16 June 2024 • 16:20 - 16:40 Japan Standard Time
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LAPYUTA (Life-environmentology, Astronomy, and PlanetarY Ultraviolet Telescope Assembly) is a future UV space telescope, which is selected as a candidate for JAXA's 6th M-class mission in 2023. Launch is planned for the early 2030s. LAPYUTA has the following four objectives. Objective 1 focuses on the subsurface ocean environment of Jupiter's icy moons and the atmospheric evolution of terrestrial planets. Objective 2 is to characterize the atmospheres and estimate the surface environment of exoplanets around the habitable zone by detecting their exospheric atmospheres. In cosmology and astronomy, Objective 3 will test whether the structures of present-day galaxies contain ubiquitous Lyα halos and reveal the physical origins of Lyα halos. Objective 4 elucidates the synthesis process of heavy elements from observations of ultraviolet radiation from hot gas immediately after neutron star mergers.
13093-19
16 June 2024 • 16:40 - 17:00 Japan Standard Time
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The Johns Hopkins Rocket Group is developing a hydrogen absorption cell to mitigate the Lyman-alpha emission challenge posed by the geocorona for astronomical observations in the Lyman ultraviolet (LUV) spectrum (100-120 nm) from low-Earth orbit. This prototype, a low-pressure (~3 torr) stainless steel chamber with two lithium fluoride (LiF) windows, enables transmission down to about 103 nm. It thermally dissociates molecular hydrogen into atomic form using a heated tungsten filament, absorbing Lyman-alpha radiation and preventing resonant scattering.
Our preliminary results with the Long-slit Imaging Dual Order Spectrograph (LIDOS) reveal variations in Lyman-alpha absorption with different filament types and indicate potential molecular hydrogen fluorescence and electron impact excitation. These findings are vital for advancing hydrogen absorption cell technology in future LUV missions.
13093-20
16 June 2024 • 17:00 - 17:20 Japan Standard Time
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The Hydrogen Emission Line Interferometric eXplorer (HELIX) is a SmallSat mission concept to study the vertical distribution and transport flux of geocoronal hydrogen that is transitioning from Earth’s upper atmosphere into the exosphere. This investigation is conducted using a dual channel, all-reflective Spatial Heterodyne Spectrometer (SHS). A SHS is a type of Fourier Transform Spectrometer that divides incoming light into 2-beams with a diffraction grating that interfere to produce a linear fringe pattern from which spectral power is obtained. The HELIX SHS has a dual ruled grating that is can be simultaneously aligned to observe the Ly-alpha and Ly-beta transitions of hydrogen. It has a spectral resolving power of ~200000 that separates the geocoronal lines from contaminating background emissions and allows exploration of the thermal and non-thermal populations of hydrogen. HELIX is designed for incorporation into a high-heritage SmallSat spacecraft platform that would be launched into low Earth orbit for a 12 month mission. This presentation describes the SHS concept, the mission requirements for HELIX, and the expected on-orbit performance of the instrument.
Monday Plenary Session
17 June 2024 • 08:30 - 10:00 Japan Standard Time
Join us for the Monday morning plenary talks.
Break
Coffee Break 10:00 - 10:20
Session 5:
UV Technology I
17 June 2024 • 10:20 - 12:00 Japan Standard Time
Session Chair:
Gillian Kyne, Jet Propulsion Lab. (United States)
13093-21
17 June 2024 • 10:20 - 10:40 Japan Standard Time
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Here we report the progress of the Compact Lyman-alpha Spatial heterodyne Spectrometer (CLASS), a novel, ultra-compact, EUV spectrometer that exceeds the capabilities of any previous ultraviolet (UV) coronagraph spectrometers with significantly less mass (~ 1 kg), size (~ show box), and compact telescope aperture (< 30 cm). Current sensors to study these questions are large instruments with considerable demands on spacecraft resources (mass, power, volume). CLASS is based on the reflective cyclical design Spatial Heterodyne Spectrometry (SHS) technique and obtains high spectral resolution profiles of Hydrogen Lyman-alpha emission at 1216Å from the solar atmosphere. High energy Solar Energetic Particles, when produced in large fluxes, can cause severe damage to satellite components and pose a radiation health risk to humans in space. However, these events' exact origin, timing, and intensity are poorly understood.
Acknowledgments: This work has been conducted at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA: copyright 2024, California Institute of Technology. Government sponsorship acknowledged.
13093-22
17 June 2024 • 10:40 - 11:00 Japan Standard Time
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In pursuit of maturing high priority UV optics technology for the Habitable Worlds Observatory, we present laboratory reflectivity results and ongoing environmental stability testing of band-selecting filters designed for the Lyman-ultraviolet bandpass (LUV; 90-120 nm) and the far-ultraviolet bandpass (FUV; 120-150 nm), and reflectance uniformity of broadband (90 – 2500nm) coatings. These band-selecting coatings were developed in coordination with the Grupo de Óptica de Laminas Delgadas (GOLD) for the Far- and Lyman-Ultraviolet Imaging Demonstrator (FLUID) sounding rocket payload. Environmental stability tests of Lyman alpha (Ly-α; 121.6 nm) suppressing filters peaked near 105 nm (F110M) and 140 nm (F140M) were conducted in testing facilities at CU Boulder. Additionally, we present initial results of UV coating development in collaboration with NASA’s Jet Propulsion Laboratory. These coatings were created using ALD at JPL, to advance the throughput efficiency of MgF2 protective capping layers for UV optics. The MgF2 coatings vary in deposition thickness and temperature. We also present initial results on the reflectance uniformity of large (≥ 6’’) Al/MgF2 ALD coated optics.
13093-23
17 June 2024 • 11:00 - 11:20 Japan Standard Time
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Astronomy-grade cameras with robust performance and heritage in the space environment have long been costly, substantially limiting capacity for space-based astronomy and creating a resource barrier to access. Additionally, ultraviolet observations have historically been limited by the low-sensitivity of most sensors in this wavelength range. The LUVCam program is designed to address both issues, providing a high-performance, low-cost, UV/optical camera system sufficiently capable to support a wide-array of space-based astronomy missions. LUVCam features a large format, low-noise, large pixel, and high quantum efficiency, commercial-off-the-shelf backside illuminated CMOS sensor, packaged with custom built readout electronics and thermomechanical structure. LUVCam is ITAR-free, and cheap to fabricate, opening up new opportunities for access to space telescopes. LUVCam has reached TRL 6, and has passed qualification testing for operation in low-earth orbit, with competitive performance from 200-900 nm. LUVCam is manifested for multiple near-term orbital missions, including a technology demonstration CubeSat, and a UV transient astronomy SmallSat.
13093-24
17 June 2024 • 11:20 - 11:40 Japan Standard Time
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The study of solar system bodies in the ultraviolet is often the study of extended sources, including vapor plumes, atmospheres, cometary tails, and planetary surfaces. These objects are traditionally studied with long-slit spectrographs that can sample only one dimension of spatial information at a time. The Ultraviolet Micromirror Imaging Spectrograph (UMIS) is a new instrument concept that will provide adaptive ultraviolet integral-field spectroscopy for the first time. UMIS employs a reconfigurable micromirror array at the focal plane to dissect portions of a 3 x 3 degree field-of-view into arbitrarily shaped apertures, each of which is then sampled spectroscopically on sub-arcminute scales and sub-nanometer resolution. The micromirror array enables this performance over a far larger field-of-regard than static image slicers, enabling efficient mapping of dynamic extended objects in the ultraviolet for the first time. UMIS is under fabrication at the University of Colorado, Laboratory for Atmospheric and Space Physics for potential future deployment on planetary science missions. This proceedings presents the UMIS optical design and development schedule.
13093-25
17 June 2024 • 11:40 - 12:00 Japan Standard Time
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In the near future, after the shutdown of the Hubble Space Telescope, observational access to the ultraviolet (UV) will be quite limited. Therefore, small missions with short development times are required to bridge the gap in this important wavelength domain. Despite the progress in adapting silicon sensors for the UV, single-photon-counting and visible-blind microchannel plate (MCP) detectors can still provide a superior signal-to-noise performance, particularly in the far-UV, and enable simple instrument designs for small and cheap missions.
Our MCP detector development aims at reaching enhanced sensitivity and increased lifetime with lower size, mass, and power consumption. Therefore, the design comprises (Al)GaN photocathodes with a tunable long-wavelength cut-off, long-life borosilicate MCPs, and a cross-strip anode with an FPGA-based readout.
In this contribution, we report on the overall status of the detector development, present the latest characterization results, and give an outlook on the mission prospects.
Break
Lunch Break 12:00 - 13:20
Session 6:
UV Technology II
17 June 2024 • 13:20 - 14:00 Japan Standard Time
Session Chair:
Jeff T. Booth, Jet Propulsion Lab. (United States)
13093-26
17 June 2024 • 13:20 - 13:40 Japan Standard Time
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Understanding the noise characteristics of high quantum efficiency silicon-based Ultraviolet detectors, developed by the Micro Devices Lab at the Jet Propulsion Laboratory, is critical for current and proposed UV missions using these devices. In this paper, we provide an overview of our detector noise characterization test bench that uses delta-doped, photon counting, Electron-multiplying CCDs (EMCCDs) to understand the fundamental noise properties relevant to all Silicon CCDs and CMOS arrays. This work attempts to identify the source of the dark current plateau that has been previously measured with photon-counting EMCCDs and is known to be prevalent in other silicon-based arrays. It is suspected that the plateau could be due to a combination of detectable photons in the tail of blackbody radiation of the ambient instrument, low-level light leaks, and a non-temperature-dependent component that varies with substrate voltage. Our innovative test setup delineates the effect of the ambient environment during dark measurements by independently controlling the temperature of the detector and surrounding environment. We present the design the test setup and preliminary results.
13093-27
17 June 2024 • 13:40 - 14:00 Japan Standard Time
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Many of the key technologies in the development queue for the Habitable Worlds Observatory (HWO) require the combined activities of 1) facility and process development for validation of technologies at the scale required for HWO and 2) deployment in the ‘real world’ environment of mission Integration & Test followed by on-orbit operations. We present a concept for the Smallsat Technology Accelerated Maturation Platform (STAMP), a parallel and closely-linked facility, laboratory, and instrument prototype development program that can be applied to any of NASA’s Future Great Observatories. We present the recommendation for the first entrant into this program, “STAMP-1”, a smallsat mission advancing key technologies that would enable the ultraviolet capabilities of HWO. Advanced broadband optical coatings, high-sensitivity ultraviolet detector systems, and multi-object selection technology would all be brought to TRL 6 and flight demonstrated through this program. STAMP-1 advances HWO technology on an accelerated timescale, reducing cost and schedule risk, and conducting a compelling program of preparatory science and workforce development for HWO.
Session 7:
Athena Instruments I
17 June 2024 • 14:00 - 15:30 Japan Standard Time
Session Chair:
Marshall W. Bautz, Massachusetts Institute of Technology (United States)
13093-28
17 June 2024 • 14:00 - 14:30 Japan Standard Time
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Following the recent reformulation of the Athena mission to meet budgetary and technical constraints, both the scientific case and the instrument design of the Wide Field Imager instrument have been reviewed to reflect the requirements and constraints of the new Athena concept. In this paper, a summary of the updated science case for WFI will be presented, along with an update of the instrument design, the status of critical technologies and future plans for model development.
13093-29
17 June 2024 • 14:30 - 14:45 Japan Standard Time
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The Wide Field Imager (WFI), one of two instruments on ESA's next large X-ray mission
Athena, is designed for imaging spectroscopy of X-rays in the range of 0.2 -15 keV. The focal plane consists of back-illuminated DEPFET sensors with high radiation tolerance. The main mechanism of degradation will be the increase of dark current due to displacement damage caused primarily by high energy protons. We investigate the effect of 62.4 MeV protons on the detector when irradiated at the operating temperature of 213 K. A total dose equivalent to 3.4 ∙ 109 10-MeV protons/cm2 was applied. Annealing effects at different temperatures were examined.
13093-30
17 June 2024 • 14:45 - 15:00 Japan Standard Time
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The Wide Field Imager of Athena is composed of two back side illuminated detector units using DEPFET sensors operated in rolling shutter readout mode. A large detector array featuring four sensors with 512 × 512 pixels each and a small detector that facilitates the high count rate capability of the WFI for the investigation of bright, point-like sources. First sensors from the flight production are now available. We present the spectral capability measured at different photon energies and asses the expected performance after years of operation in space using Monte Carlo simulations to combine all information gained by measurements.
13093-31
17 June 2024 • 15:00 - 15:30 Japan Standard Time
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The Athena mission underwent a redefinition phase since July 2022, driven by the imperative to reduce the mission cost for the European Space Agency while maintaining its flagship character. This most notably lead to a modification of the X-ray Integral Field Unit (X-IFU) cryogenic architecture. Passive cooling via radiative panels at spacecraft level (V-grooves) now provides a 50K thermal environment to the X-IFU cryostat. 4K cooling is achieved through a remote active cooler, with a multi-stage Adiabatic Demagnetization Refrigerator delivering the final 50 mK temperature required by the detectors.
Amidst these changes, the core concept of the readout chain remains robust, utilizing Transition Edge Sensor microcalorimeters and Time-Division Multiplexing. Noteworthy is the introduction of a slower pixel, enabling an increase in the multiplexing factor (from 34 to 48) without compromising the energy resolution. This mitigates the reduction of the field of view (from 5’ to 4’) while reducing the number of channels and thus the resource demands on the system.
In this contribution, we will give an overview of this new instrument architecture, addressing its main functional chains.
Break
Coffee Break 15:30 - 16:00
Session 8:
Athena Instruments II
17 June 2024 • 16:00 - 17:30 Japan Standard Time
13093-32
17 June 2024 • 16:00 - 16:15 Japan Standard Time
Show Abstract +
This paper presents the progress done on early demonstrations (warm electronics, cryo-harness breadboarding,...), while providing an update to the detection-chain design description of the Athena X-IFU instrument.
13093-33
17 June 2024 • 16:15 - 16:30 Japan Standard Time
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The X-IFU is one of the two instrument of ATHENA, the next ESA X-ray observatory. It is a cryogenic spectrometer based on a large array of TES microcalorimeters. To reduce the particle background, the TES array works in combination with a Cryogenic AntiCoincidence detector (CryoAC).
The CryoAC is a 4-pixels detector, based on ~1 cm2 silicon absorbers sensed by Ir/Au TES. It is required to have wide energy bandwidth (from 20 keV to ~1 MeV), high efficiency (< 0.014% of missed particles), low dead-time (< 1%) and good time-tagging accuracy (10 μs at 1σ).
We have developed an end-to-end simulator of the CryoAC detector, composed of several modules. First, the in-flight flux of background particles is assessed by Geant4 simulations. Then, the current flow in the TES is evaluated by solving the electro-thermal equations of microcalorimeters, and the detector output signal is generated by simulating the SQUID FLL dynamics. Finally, the output is analyzed by a high-efficiency trigger algorithm, producing the simulated CryoAC telemetry.
Here, we present in detail this end-to-end simulator, and how we used it to define the new baseline CryoAC configuration in the newAthena context.
13093-34
17 June 2024 • 16:30 - 16:45 Japan Standard Time
Show Abstract +
This paper describes the redesign performed on the X ray Integral Field Unit Focal Plane Assembly (X-IFU FPA) Development Model (DM) in preparation of the instrument PDR and MAR, with a focus on the mechanical modifications of the T0 detector stage. A new, flight sized detector is used, as well as flight scalable interconnections to route the TDM signals to the MUX chip and subsequent cold electronics. In addition the development of several critical technologies within the DM1.1 are described. These include fixation of the main TES array to the metal support, a dedicated wire bonding process of the main TES array to the side panel MUX carrier chips and interconnection of the super-conducting Nb flex cables to the connecting Printed Circuit Boards (PCB).
13093-35
17 June 2024 • 16:45 - 17:00 Japan Standard Time
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This paper describes the micro-vibrational characterization of the Development Model (DM) of the X ray Integral Field Unit Focal Plane Assembly (X-IFU FPA) for the Athena X-ray observatory. We discuss the power dissipation occurring when FPA modes are excited. We compare amplitude and phase measured by X-Z accelerometers, thermometers response and the pixels DC baseline signal due to acceleration provided by actuator towards the FPA center of mass. Impact of the micro-vibrations on the thermal stability at the detectors level and the possible degradation on the pixels performance will be discussed in detail.
13093-36
17 June 2024 • 17:00 - 17:15 Japan Standard Time
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This paper describes the strategy and planned implementation of the ground calibration of the X-IFU microcalorimeter spectrometer on-board Athena, the X-ray observatory from ESA to be launched after the mid-2030s. X-IFU is the second generation of space microcalorimeter instrument, and its calibration strategy benefits from the experience acquired on the present Japanese-US built Resolve instrument on-board XRISM. This calibration plan takes into account the reformulation of the Athena mission and its instruments that took place in 2022-23. The X-IFU calibration strategy is presented along with the set of X-ray sources needed for the ground calibration and the the definition of the sequences for using them.
13093-165
17 June 2024 • 17:15 - 17:30 Japan Standard Time
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The X-ray integral field unit (X-IFU) will be a microcalorimeter instrument on ESA’s Athena observatory. The X-IFU array will consist of ~ 1.5k transition edge sensors (TESs) on a 317-micron pitch, optimized for the energy range of 0.2-12 keV. The instrument provides a spectral resolution of 3 eV at energies of up to 7 keV and is read out using time division multiplexing (TDM). We report on the status and plan for continued maturation of the X-IFU array. This includes efforts to optimize the pixels for reduced magnetic field sensitivity and reduced dynamic range usage (needed to optimally couple them to the readout with lowest possible noise). We describe the design and characterization of the first full scale microcalorimeter arrays that have flight-like electrical and mechanical interfaces. These arrays are being developed for a focal-plane assembly demonstration model in Europe and are a precursor to the X-IFU engineering model.
Tuesday Plenary session
18 June 2024 • 08:30 - 10:00 Japan Standard Time
Join us for the Tuesday morning plenary talks.
Break
Coffee Break 10:00 - 10:20
Session 9:
Optics I
18 June 2024 • 10:20 - 12:00 Japan Standard Time
Session Chair:
Marcos Bavdaz, European Space Agency (Netherlands)
13093-37
18 June 2024 • 10:20 - 10:40 Japan Standard Time
Show Abstract +
The Off-plane Grating Rocket Experiment (OGRE) is a NASA suborbital rocket mission for high-performance X-ray spectroscopy. The nominal payload utilizes lightweight, polished-Si optics fabricated by NASA's Goddard Space Flight Center, a reflection grating array fabricated at Penn State with key industrial collaborations, and an EM-CCD based camera fabricated by XCAM in collaboration with the Open University. In preparation for the nominal mission, we will fly a pathfinder rocket that swaps the polished-Si telescope out for the JET-X telescope. This is one of three telescopes originally made for Spectrum-x-gamma with one currently flying on Swift and one slated for Pathfinder-OGRE, being lent by the Italian Space Agency. Here we report on the progress of the OGRE program, overview of the Pathfinder-OGRE mission, and updates on the nominal payload.
13093-38
18 June 2024 • 10:40 - 11:00 Japan Standard Time
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Improved X-ray/UV spectroscopy is needed for studies of exoplanet host systems, the evolution of galaxies, and the physics of extreme astrophysical conditions. Efficient, high-resolution X-ray / UV spectrometers would meet this need, but realizing such instruments, particularly in compact formats like SmallSats, are often gated by the fabrication of a grating that meets the size, shape, diffractive design, and performance requirements of the spectrometer.
We report on an effort to make custom, high performance gratings on curved surfaces using electron-beam lithography (EBL). We have made modestly-sized gratings (39 mm X 20 mm) on cylindrical surfaces with sag comparable to that of a grazing-incidence optic (> 1 mm). Our approach uses interferometric measurements of diffracted orders to assess the fidelity of EBL in realizing the desired grating, providing a direct measurement of the technology’s current capabilities and informing development efforts. We also report on the fabrication and testing of a diffractive silicon mirror operating at grazing incidence, as well as an optical design for a test of a novel, two-element spectrometer system.
13093-39
Improved efficiency critical-angle transmission gratings for high-resolution soft x-ray spectroscopy
18 June 2024 • 11:00 - 11:20 Japan Standard Time
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Critical-angle transmission (CAT) gratings are an enabling technology for the Arcus-Probe mission, which addresses high-priority science goals from Astro2020. We previously reported x-ray results from quasi-fully illuminated, co-aligned CAT gratings showing record-high resolving power R = lambda/Delta lambda up to 1.3x10^4 in 18th and 21st orders at Al-K, and diffraction efficiency of blazed orders in agreement with pencil beam synchrotron measurements and model predictions at O-K. We will give updates on enhanced diffraction efficiency for CAT gratings that were chemically thinned after fabrication.
13093-40
18 June 2024 • 11:20 - 11:40 Japan Standard Time
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We report on the status of an X-ray optics development effort at Goddard Space Flight Center. The development effort is designed to enable future flagship missions like Lynx in the long term and to support Probe missions and Explorer missions like AXIS, HEX-P, LEM, and STAR-X, in the near term. It takes into consideration the three major work areas of building an X-ray mirror assembly, i.e., technology, engineering, and production, while focusing its resources on developing and maturing a technology based single crystal silicon. Boiled down to the most essentials, the development tackles four major technical areas: fabrication, coating, alignment, and bonding of thin, lightweight mirror segments. The technology is based on single crystal silicon, whose lack of internal stress makes it possible to use many polishing techniques to make the best possible thin, lightweight mirror segments. We will report results achieved with repeated building and testing mirror modules, as well as knowledge and lessons learned in each of the four technical areas.
13093-41
18 June 2024 • 11:40 - 12:00 Japan Standard Time
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Light-weight X-ray mirrors with a high-angular resolution and a large effective area are required to clarify the physical mechanism of the coevolution of galaxies and black holes. To realize such X-ray mirrors, we are developing X-ray mirrors using the carbon fiber reinforced plastic (CFRP); CFRP is a light, but strong material, and it can be processed into a variety of shapes. However, CFRP has a finely textured surface, which is called print through. The surface is too rough to reflect X-rays due to the print though. In order to mitigate the print through, we developed a method to form a thin amorphous NiP layer on the surface of CFRP. Then the NiP surface was finished by ultra-precision machining technology to achieve sufficient surface roughness to reflect X-rays. An X-ray reflectivity measurement for a prototype CFRP-NiP flat mirror using the ISAS X-ray beam line confirmed that the surface roughness was sufficient to reflect X-rays of a few keV. We are also developing the prototype of the Wolter-I type mirror, which is reported in this talk.
Break
Lunch Break 12:00 - 13:20
Session 10:
Optics II
18 June 2024 • 13:20 - 15:20 Japan Standard Time
Session Chair:
William W. Zhang, NASA Goddard Space Flight Ctr. (United States)
13093-42
18 June 2024 • 13:20 - 13:40 Japan Standard Time
Show Abstract +
Italy, through ASI funding and INAF-OAB leadership, is actively pursuing a technology development roadmap for the realisation of thin glass monolithic shell. This paper outlines the progress made in advancing various phases of the process and in procuring new substrates.
13093-43
18 June 2024 • 13:40 - 14:00 Japan Standard Time
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Alongside the development of high resolution, full-shell replicated X-ray optics, MSFC is also pursuing the development of advanced thin film coatings. Current direct deposition methods for full shell coatings involve a radio frequency (RF) sputtering system with a wire-like target that slowly deposits a single layer of metal on the inner surface of the shell. As coating designs become more complex, a new method of direct deposition is required. Due to the promising results of on-going hard X-ray multilayer development at Marshall, recent funding has been granted to procure a new DC magnetron deposition system to directly deposit multilayer coatings onto the reflective surface of full shell optics. This new system will vastly expand MSFC’s coating capabilities for full shell optics to include bilayer and multilayer coated designs. The design of this new system and its applications for hard X-ray mission concepts such as SuperHERO and HEX-P, with be presented and discussed.
Show Abstract +
With the endorsement of the NewAthena (New Advanced Telescope for High ENergy Astrophysics) mission by ESA’s Science Programme Committee in November 2023, the preparations for this next generation X-ray observatory have shifted to a higher gear. Competitive system studies and technology preparation activities are being implemented, aiming to demonstrate readiness for the mission adoption early 2027 and the subsequent mission implementation.
The Silicon Pore Optics (SPO) enables the NewAthena mission, delivering an unprecedented combination of good angular resolution, large effective area and low mass. The SPO technology builds significantly on spin-in from the semiconductor industry and is designed to allow a cost-effective flight optics implementation, compliant with the programmatic requirements of the mission.
This paper will provide an overview of the activities preparing the implementation of the NewATHENA optics.
13093-45
18 June 2024 • 14:20 - 14:40 Japan Standard Time
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The European Space Agency (ESA), cosine and its partners have been developing for more than 15 years the Silicon Pore Optics (SPO) technology. SPO enables the next generation of space x-ray telescopes, with increased sensitivity and resolution. NewAthena, the New Advanced Telescope for High Energy Astrophysics, has just been endorsed by ESA as one of its L-class mission, to launch in 2037. NewAthena’s optic is modular and consists of up to 600 mirror modules that form together a ~2.5 m diameter x-ray mirror with a focal length of 12 m and an angular resolution of 9 arc-seconds half-energy width. The total geometric polished mirror surface is ~300 m2, which will focus x-rays with an energy of about 0.3 – 10 keV onto two detectors, a wild-field imager (WFI) and an imaging spectrometer (XIFU). Building hundreds of such SPO mirror modules in a cost-efficient and timely manner is a formidable task and subject of a dedicated ESA technology development program.
We present in this paper the status of the optics production, and illustrate not only recent X-ray results but also the progress made on the environmental testing, manufacturing and assembly aspects of SPO based optics.
13093-46
18 June 2024 • 14:40 - 15:00 Japan Standard Time
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High-energy astrophysics missions demand cutting-edge technologies to assure their maximum observational capabilities. This study explores multilayer coatings for X-ray mirrors, specifically assessing their potential applications for the NewAthena mission and other possible future high-energy missions. Our work emphasizes the design parameters crucial for enhancing mirror performance and investigates the experimental challenges related to the fabrication and performance evaluation of multilayer coatings.
We present various concept designs for both soft and hard X-ray focusing telescopes, incorporating simple single-layer and bilayer coatings, with a particular focus on linear and depth-graded multilayer coatings. Leveraging state-of-the-art understanding and modeling of relevant effects influencing telescope performance enables a realistic extension of coating designs to higher energies.
The implications of our findings not only endorse the use of multilayer coatings for the NewAthena mission but also offer insights into the broader landscape of future high-energy astrophysics missions.
13093-47
18 June 2024 • 15:00 - 15:20 Japan Standard Time
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Regularly, future mission X-ray optics are tested and calibrated at the PANTER X-ray test facility of the Max-Planck-Institute for Extraterrestrial Physics. The ATHENA mission has just completed a science and hardware redefinition phase as the NewATHENA mission. During this one-and-a-half-year redefinition phase, the development of the baseline Silicon Pore Optics SPOs continued, resulting in the fabrication of the first SPO mirror modules with all the NewATHENA characteristics (dimensions, rib spacing, and coating). At PANTER, these NewATHENA SPOs will be measured and characterized. This characterization comprises the on- and off-axis point spread function half energy widths. Furthermore, effective area measurements covering the energy range of NewATHENA will be performed. This presentation will provide an overview of the results obtained from recent campaigns.
Break
Coffee Break 15:20 - 15:50
Session 11:
Operational Missions
18 June 2024 • 15:50 - 17:30 Japan Standard Time
Session Chair:
Hironori Matsumoto, Osaka Univ. (Japan)
13093-48
Updates of the Einstein Probe mission
(Invited Paper)
18 June 2024 • 15:50 - 16:30 Japan Standard Time
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The Einstein Probe (EP) is a space mission dedicated to X-ray time-domain astrophysics, with a broad range of scientific goals. It will carry two instruments, one wide-field X-ray telescope (WXT) to monitor the soft X-ray sky in 0.5-4keV with a 3600 square-degree field-of-view, and one narrow-field X-ray telescope (FXT) for deep follow-up observations in 0.3-10keV and precise source locating. The Einstein Probe is a mission of the Chinese Academy of Sciences in collaboration with ESA, MPE and CNES. This talk will introduce the mission and its current status.
13093-49
18 June 2024 • 16:30 - 16:50 Japan Standard Time
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What do medical imaging and astronomy have in common? Whether it is detecting tumors or observing colliding neutron stars, both fields can benefit from the same sensor technology. When observing radiation in the MeV-band (0.1-100 MeV) from celestial sources, one faces challenges like low flux, limited interaction probability, three energy loss processes, and a high background radiation rate. Present MeV-band observatories suffer from poor sensitivity, and new state-of the-art detector technology will be a key contributor to improve sensitivity of future observatories. The detector group at DTU Space has developed a 3D CZT drift strip detector technology to meet the demands of future high-energy detectors. This advancement might also prove advantageous for emerging Low Dose Molecular Breast Imaging (LD-MBI) systems for breast cancer diagnosis. In this study, we present the results of the novel large area 3D CZT drift strip detectors (4x4x0.5cm3) developed through collaboration between DTU Space and Kromek.
13093-50
18 June 2024 • 16:50 - 17:10 Japan Standard Time
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As the Advanced CCD Imaging Spectrometer (ACIS) on the Chandra X-ray Observatory completes a quarter century of on orbit operations, it continues to perform well and produce spectacular scientific results. The response of ACIS has evolved over the lifetime of the observatory due to radiation damage, molecular contamination, changing particle environment, and aging of the spacecraft in general. We present highlights from the instrument team's monitoring program and our expectations for the future of ACIS. Performance changes on ACIS continue to be manageable, and do not indicate any limitations on ACIS lifetime. We examine aspects of the design and operation of ACIS that have impacted its long lifetime with lessons learned for future instruments.
13093-51
18 June 2024 • 17:10 - 17:30 Japan Standard Time
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RHESSI was a solar X-ray mission that observed the Sun at X-ray and gamma-ray wavelengths for 16 years, with an energy range covering 3 keV - 17 MeV. RHESSI instrumentation consisted of nine cryocooled, segmented, germanium detectors. We report on the performance of these detectors over the course of 16 years of science operations in a mid-latitude, low-Earth orbit environment. We assess the evolution of the energy gain and energy calibration for each detector, the segmentation status of the detectors over time, and the effectiveness of detector annealing in restoring performance. We highlight some of the challenges associated with determining the calibration over such a long on-orbit time period. These results provide valuable context for future X-ray and gamma-ray space missions.
Wednesday Plenary Session
19 June 2024 • 08:30 - 10:00 Japan Standard Time
Join us for the Wednesday morning plenary talks.
Break
Coffee Break 10:00 - 10:20
Session 12:
XRISM I
19 June 2024 • 10:20 - 12:15 Japan Standard Time
Session Chair:
Kazuhiro Nakazawa, Nagoya Univ. (Japan)
13093-52
19 June 2024 • 10:20 - 10:50 Japan Standard Time
Show Abstract +
The X-Ray Imaging and Spectroscopy Mission (XRISM) project was initiated in 2018. Following the development of onboard components, the proto-flight was conducted from 2021 to 2023 at JAXA Tsukuba Space Center. The spacecraft was launched from JAXA Tanegashima Space Center on September 7, 2023, and onboard components, including the observation instruments, were activated during the three months of the in-orbit commissioning phase. Following the previous report in 2020, we report the spacecraft ground tests, the launch operation, in-orbit operations, and the status and plan of initial and following guest observations.
13093-53
19 June 2024 • 10:50 - 11:20 Japan Standard Time
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The initial on-orbit checkout of the soft X-ray spectroscopic system (Resolve) on board the XRISM satellite is summarized. XRISM was launched on September 6, 2023 (UT) and has been undergoing initial checkout since then. Immediately after launch, cooling of the vessel covering the sensor (Dewar) was advanced, and the first cycle of adiabatic demagnetization refrigerator (ADR) was performed on Day 32 to transition the sensor to steady-state operational temperature conditions. Subsequently, the filter wheel which supports energy calibration, was started up.
The energy scale is highly sensitive on the temperature environment around the sensor. The gain correction by referring to the calibration X-ray lines together with the temperature of the sensor. For an optimization of the cooler frequency, we took the noise spectra by scanning the coolers frequencies, which were made with three steps and were taken over six consequent days at the last step. In addition, the gate valve (GV), which protects the inside of the Dewar from outside air pressure at launch, will be opened to bring the system to a state where it is ready for regular operations.
13093-54
19 June 2024 • 11:20 - 11:40 Japan Standard Time
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Xtend is one of the two telescopes onboard the X-ray imaging and spectroscopy mission (XRISM), which was launched on September 7th, 2023. Xtend comprises the Soft X-ray Imager (SXI), an X-ray CCD camera, and the X-ray Mirror Assembly (XMA), a thin-foil-nested conically approximated Wolter-I optics. Before the launch of XRISM, we conducted a month-long spacecraft thermal vacuum test. The performance verification of the SXI was successfully carried out in a course of multiple thermal cycles of the spacecraft. About a month after the launch of XRISM, the SXI has been carefully activated and the soundness of its functionality has been checked by a step-by-step process. We here review these pre- and post-launch status of Xtend. A few initial results verifying the Xtend performance will be also presented.
13093-55
19 June 2024 • 11:40 - 12:00 Japan Standard Time
Show Abstract +
We present the design and performance of the XRISM Soft X-Ray Spectrometer Resolve, successfully launched on a JAXA H-IIA rocket September 7, 2023. The instrument uses a 36-pixel array of microcalorimeters at the focus of a grazing-incidence x-ray mirror. The instrument has achieved an energy resolution of 4.5 eV (FWHM) at 6. The overall cooling chain was designed to provide a lifetime of at least 3 years in orbit and operate without liquid helium to provide redundancy and the longest operational lifetime for the instrument. Early indications that the cryogen lifetime will exceed 4 years. X-rays are focused onto the array with a high-throughput grazing incidence X-ray Mirror Assembly with over 200 nested two-stage X-ray reflectors. A series of onboard X-ray calibrations sources allow simultaneous energy scale calibration lines simultaneously while observing celestial sources. The inflight performance of Resolve will be described along with a summary of the scientific capabilities.
13093-56
19 June 2024 • 12:00 - 12:15 Japan Standard Time
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The XRISM/Resolve instrument is an on-orbit high-resolution non-dispersive x-ray spectrometer with a resolving power of nearly 1300 at 6 keV and a broad bandpass from below 0.3 keV to above 12 keV. The instrument will provide essential diagnostics for nearly every class of x-ray emitting objects from the atmosphere of Jupiter to the outskirts of galaxy clusters. Here we present the first results of the on-orbit performance of the Resolve detector system after its launch in early September 2023. We compare the performance to the theoretical predictions, preflight measurements, the expected additional noise sources on-orbit, and the performance of the almost identical Hitomi/SXS.
Break
Lunch Break 12:15 - 13:50
Session 13:
XRISM II
19 June 2024 • 13:50 - 15:05 Japan Standard Time
Session Chair:
Wei Cui, Tsinghua Univ. (China)
13093-58
19 June 2024 • 13:50 - 14:05 Japan Standard Time
Show Abstract +
The X-ray astronomy satellite XRISM, which was launched in 2023, carries a high-energy resolution X-ray spectrometer called Resolve. The X-ray Mirror Assembly (XMA) is the X-ray optics of XRISM and Resolve's XMA is called Resolve-XMA. The performance of the Resolve-XMA was extensively measured on the ground and verified to meet the requirements. This presentation reports on the performance of the Resolve-XMA with first observations in orbit. The aim point determination and its accuracy will be presented. The effective area will be measured at different energies. The PSF will be measured in Resolve's 3'x3' FoV with its 35 pixels. With these measurements, we will judge whether the on-board performance differs from the ground measurement result and meets the requirement.
13093-59
19 June 2024 • 14:05 - 14:20 Japan Standard Time
Show Abstract +
Two complementary X-ray telescopes, Resolve and Xtend are on-boarded on the X-ray astronomy satellite XRISM (X-Ray Imaging and Spectroscopy Mission). In this presentation, in-orbit performance of the Xtend-XMA will be reported. Xtend uses an X-ray CCD camera as its focal plane detector, which has high spatial resolution and a wide field of view. This makes it possible to obtain detailed PSF of the Xtend-XMA. And also the energy resolution of the X-ray CCD camera makes it possible to determine the energy-dependent effective area of the Xtend-XMA. We can verify that these performances are sufficient to meet the mission requirements and that the launch has not affected the performance of Xtend-XMA.
Show Abstract +
We report on the current status of XRISM science operations from the launch to today, with an introduction of the ground system in XRISM science operations. Currently, XRISM is in the initial observation phase, and operations during the start-up of mission instruments and data processing of the observation data are being carried out. After the transition to the nominal operation phase, we plan and operate observations of each celestial target for in-orbit calibration and functionality checks, and process the data. We also start to call for proposals for Guest Observers and set up a help desk, which provides analysis supports for users.
13093-61
19 June 2024 • 14:35 - 14:50 Japan Standard Time
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We summarize the detail design of the timing system of newly born X-ray satellite XRISM, including both onboard instruments and off-line data-processing tools. The absolute timing accuracy of 1.0 msec is required for the system. We also report the results of both the ground timing test and in-orbit verification observation using a millisecond pulsar on the timing performance of the XRISM timing system in the nominal operating mode, i.e., assigning time stamp using the GPS signals from the GPS receiver onboard the spacecraft.
13093-62
19 June 2024 • 14:50 - 15:05 Japan Standard Time
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The Resolve instrument aboard the X-ray Imaging and Spectroscopy Mission (XRISM) is a 36-pixel microcalorimeter spectrometer that provides non-dispersive spectroscopy with ~5 eV spectral resolution in the soft x-ray waveband. Resolve has a requirement to provide absolute energy-scale calibration of +/- 2 eV from 0.3-12 keV. In this presentation we describe our ground calibration strategy and results of calibration campaigns from 2018-2022, including a discussion of improvements in the ground calibration approach compared to Hitomi and a description of Resolve's final pre-launch gain scales, which indicate that the energy scale of the array can be absolutely calibrated to better than +/- 0.5 eV from 0.3-17.5 keV. We provide an assessment of how well these pre-launch gain scales correct on-orbit data and discuss approaches for updating the gain curves.
Break
Coffee Break 15:05 - 15:35
Session 14:
Detectors
19 June 2024 • 15:35 - 17:15 Japan Standard Time
Session Chair:
Roland H. den Hartog, SRON Netherlands Institute for Space Research (Netherlands)
13093-63
19 June 2024 • 15:35 - 15:55 Japan Standard Time
Show Abstract +
High spatial- and spectral-resolution X-ray capabilities are essential for future strategic missions to address the key priorities set forth by the Astro2020 Decadal Survey This will require megapixel X-ray imaging detectors more capable than any available today, providing frame rates at least a factor of 20 faster and pixel aspect ratios twice as large, while retaining the low noise and excellent spectral performance of current instruments.
We present recent results from our NASA-funded technology development effort to produce a prototype CCD detector for AXIS, the Advanced X-ray Imaging Satellite mission concept recently submitted in response to the NASA Astrophysics Probe call. Thi project is developing a 16-output, 1440 x 1440 pixel frame-store CCD with the same pixel size (24 µm) and depletion depth (100 µm) as the proposed AXIS detector. This device uses the low-voltage, single-polysilicon gate and low-noise pJFET technologies proven in previous work. We describe our strategy for optimizing CCD output amplifier design, present results from testing a similar, prior-generation CCD with the Multi-Channel Readout Chip (MCRC) ASIC developed at Stanford University.
13093-64
19 June 2024 • 15:55 - 16:15 Japan Standard Time
Show Abstract +
Photon counting detectors have made large strides in recent years. Quanta image sensor (QIS), the electron-multiplying charge-coupled device (EMCCD), and single photon avalanche diode (SPAD) are three leading single photon counting silicon technologies. An example of each device has been fully characterized and evaluated. Their performance and value add have been determined for future space flight missions.
13093-65
19 June 2024 • 16:15 - 16:35 Japan Standard Time
Show Abstract +
Bringing artificial intelligence (AI) alongside next-generation X-ray imaging detectors, including CCDs, DEPFET and CMOS sensors, enhances their sensitivity to achieve many of the flagship science cases targeted by future X-ray observatories, based upon low surface brightness and high redshift sources. Machine learning algorithms operating on the raw frame-level data provide enhanced identification of background vs. astrophysical X-ray events, and enhanced energy reconstruction, by considering all of the signals in a single frame holistically.
We have developed prototype machine learning algorithms to identify valid X-ray and cosmic-ray induced background events, trained and tested upon a suite of realistic end-to-end simulations that trace the interaction of cosmic ray particles and their secondaries through the spacecraft and detector. These algorithms demonstrate that AI can reduce the unrejected instrumental background by up to 30% compared with traditional filtering methods, and can recover up to 98% of valid X-ray signals that are often rejected.
13093-66
19 June 2024 • 16:35 - 16:55 Japan Standard Time
Show Abstract +
The DarkNESS CubeSat will deploy skipper-CCDs, the most sensitive silicon detectors to date, on a nano-satellite to study the diffuse X-ray background in the Milky Way and search for Dark Matter (DM). DM is an abundant, but invisible, presence in our Universe. It dictates how galaxies were initially formed and influences their dynamics today. The total mass of DM in the universe is known to be five times that of ordinary matter, but its true nature remains elusive, and its identity is one of the biggest questions in science today. We will search for DM by mapping the Galaxy's diffuse X-ray spectrum using an array of skipper-CCDs on a nanosatellite in LEO. This will address the experimental conundrum associated with the observation of an unidentified 3.5~keV X-ray line, potentially produced from the decay of a DM particle. The mission will also perform a direct search for low-mass, strongly-interacting DM candidate particles that would not penetrate the Earth’s atmosphere and are therefore inaccessible to terrestrial DM experiments
13093-67
19 June 2024 • 16:55 - 17:15 Japan Standard Time
Show Abstract +
Pixelated detectors aboard modern space X-ray telescopes offer excellent, simultaneous imaging and spectroscopic capabilities. However, in orbit measurements with these devices are hampered by the background induced by charged particles, primarily cosmic-ray protons, interacting with the spacecraft and detectors, which makes the task of studying faint, low surface brightness objects challenging. The traditional background reduction algorithms analyze the deposited signal as a separate, multiple-pixel island, ignoring contextual information present on the same readout frame.
Machine learning models can effectively capture this context by recognizing spatial and energetic correlations between signals left by a primary cosmic ray and secondaries produced during interaction of the incident particle with the body of the detector. In this work we present a study of different approaches to maximize the context information available to the deep neural network models to further improve the background reduction capabilities.
Thursday Plenary Session
20 June 2024 • 08:30 - 10:00 Japan Standard Time
Join us for the Thursday morning plenary talks.
Break
Coffee Break 10:00 - 10:20
Session 15:
Missions I
20 June 2024 • 10:20 - 12:00 Japan Standard Time
13093-68
20 June 2024 • 10:20 - 10:40 Japan Standard Time
Show Abstract +
The SVOM (Space-based multi-band astronomical Variable Objects Monitor) French-Chinese mission is dedicated to the detection, localization and study of Gamma Ray Bursts (GRBs) and other high-energy transient phenomena. Two instruments ECLAIRs and MXT are developed under the responsibility of the National French Space Agency (CNES), the first is dedicated to GRB detection in Gamma ray band and the second to fine localize and observe the follow-up in soft X-ray band. After a reminder of the final instrument design, we will provide details on the past year dedicated to integration and validation on the Chinese satellite, how activities were shared between China and France and finally the main results will be presented. To conclude, a status will be made on the first results of the commissioning of the instruments in flight.
13093-69
20 June 2024 • 10:40 - 11:00 Japan Standard Time
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The Micro-channel X-ray Telescope (MXT) is the X-ray telescope aboard the SVOM mission, to be launched in Spring 2024. The MXT camera is housing a 256×256 pixels pnCCD detector, characterised in 2021 at the PANTER facility during the end-to-end tests of the flight instrument. The MXT camera will suffer from proton irradiation when SVOM crosses Earth’s radiation belts. A spare model was irradiated at the Arronax cyclotron facility, and then characterized at the X-ray Metrology beamline of the SOLEIL Synchrotron facility. This work reviews the characterization of detector before and after irradiation, in order to evaluate the scientific performances of MXT camera over the SVOM mission lifetime. Some preliminary in-flight data may also be presented.
Show Abstract +
Hot Universe Baryon Surveyor (HUBS) is proposed as a dedicated probe of hot gas in galaxy ecosystems, which is beyond the capabilities of current X-ray observatories but holds a key to understanding galaxy evolution. It employs a non-dispersive spectrometer based on TES microcalorimeters, enabling both high-resolution spectroscopy and imaging. In this contribution, we briefly describe the progress on the development of TES microcalorimeters for HUBS, as well as that of supporting key technologies including frequency-division multiplexing readout electronics, cryocoolers and adiabatic demagnetization refrigerator, and wide-field X-ray optics. We also show the design of a pathfinder experiment (DIXE), which is being considered for inclusion in the science portfolio of the China Space Station, not only to advance the TRLs of the key technologies for HUBS, but to conduct a high-resolution X-ray spectroscopic survey for the first time.
13093-91
20 June 2024 • 11:20 - 11:40 Japan Standard Time
Show Abstract +
BlackCAT is an X-ray coded-aperture-telescope on a 6U CubeSat platform that is expected to launch in 2025. It is designed for observations of X-ray sources and new transients in the 0.5–20 keV band. The instrument will have a wide field of view (0.85 steradian) and be capable of catching gamma ray bursts from the distant universe, galactic transients, flares from blazars, and monitoring the X-ray sky for rare and exciting events including gravitational-wave X-ray counterparts, magnetar flares, supernova shock breakouts, and tidal disruption events. The mission will thus function as a multiwavelength/messenger complement to present and future facilities, while providing rapid notifications. Silicon X-ray hybrid CMOS detectors will form the focal plane array. In addition to carrying out its science programs, BlackCAT will also serve as a pathfinder for future economical sky monitoring networks. An overview of mission design, science, and status will be presented.
13093-72
20 June 2024 • 11:40 - 12:00 Japan Standard Time
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(Additional authors not shown)
The Large Area Detector (LAD) is the high-throughput, spectral-timing instrument onboard the eXTP mission, a major project of CAS and CNSA with a large European participation. The eXTP mission is currently completing its phase B study, with a target launch at the end-2029. The eXTP scientific payload includes four instruments (SFA, PFA, LAD and WFM) offering unprecedented simultaneous wide-band X-ray timing and polarimetry sensitivity.
The LAD instrument design envisages a deployed 3 m2 effective area in the 2-30 keV energy range, achieved through the technology of the large-area Silicon Drift Detectors - offering a spectral resolution of up to 200 eV FWHM at 6 keV - and of capillary plate collimators - limiting the field of view to about 1 degree. In this paper we will provide an overview of the LAD instrument design, its current status of development and anticipated performance.
Break
Lunch Break 12:00 - 13:20
Session 16:
Missions II
20 June 2024 • 13:20 - 15:20 Japan Standard Time
Session Chair:
Jessica A. Gaskin, NASA Marshall Space Flight Ctr. (United States)
13093-73
20 June 2024 • 13:20 - 13:40 Japan Standard Time
Show Abstract +
The eXTP (enhanced X-ray Timing and Polarimetry) mission is a major project of the Chinese Academy of Sciences (CAS), with a large involvement of Europe. The scientific payload of eXTP includes four instruments: SFA (Spectroscopy Focusing Array) and PFA (Polarimetry Focusing Array) - led by China - LAD (Large Area Detector) and WFM (Wide Field Monitor) - led by Europe (Italy and Spain, respectively). eXTP with its set of four instruments offers an unique simultaneous wide-band X-ray timing and polarimetry sensitivity. In particular, the WFM for eXTP will be a wide field X-ray monitor instrument in the 2-50 keV energy range. It will have an unprecedented combination of large field of view and imaging, with a very good spectral resolution, down to 2 keV. This will allow eXTP making very relevant discoveries of the variable and transient X-ray sky. Currently eXTP/WFM is in phase B2, after successfully undergoing the I-SRR (Instrument System Requirements Review) in mid-2023. Besides an overview of the eXTP/WFM, the more relevant details about the current work in Phase B2, including the manufacturing and testing of the demonstration models of the WFM subsystems, will be presented.
13093-74
20 June 2024 • 13:40 - 14:00 Japan Standard Time
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HERMES (High Energy Rapid Modular Ensemble of Satellites) is a space-borne mission based on a constellation of six nano-satellites flying in a low-Earth orbit (LEO). The 3U CubeSats, to be launched end-2024, host miniaturised instruments with a hybrid Silicon Drift Detector/GAGG:Ce scintillator photodetector system, sensitive to X-rays and gamma-rays in a large energy band. HERMES will operate in conjunction with Australian Space Industry Responsive Intelligent Thermal (SpIRIT) 6U CubeSat, to be launched in late 2023.
HERMES will probe the temporal emission of bright high-energy transients such as Gamma-Ray Bursts (GRBs), ensuring a fast transient localization (with arcmin-level accuracy) in a field of view of several steradians exploiting the triangulation technique.
HERMES intrinsically modular transient monitoring experiment represents a keystone capability to complement the next generation of gravitational wave experiments. Here we’ll outline the scientific case, development and programmatic status of the mission.
13093-75
20 June 2024 • 14:00 - 14:20 Japan Standard Time
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HiZ-GUNDAM is a candidate of future satellite for the Japanese competitive M-class mission by ISAS/JAXA to progress a time-domain astronomy and multi-messenger astronomy with gamma-ray burst (GRB) phenomena. The science goals are (1) to probe the early universe with high redshift GRBs at z > 7, and (2) to promote the gravitational wave and neutrino astronomy with X-ray transients. HiZ-GUNDAM team is working on the concept study phase. We will introduce the sciences and mission overview of HiZ-GUNDAM as well as the latest status.
13093-76
20 June 2024 • 14:20 - 14:40 Japan Standard Time
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The HiZ-GUNDAM mission is one of the candidates for the JAXA's competitive M-class missions. HiZ-GUNDAM revolutionizes our understanding of the high redshift universe and promotes multi-messenger astronomy. Combining a highly sensitive wide-field X-ray monitor, a near-infrared telescope, and autonomous spacecraft slew capability makes a powerful machine to hunt interesting X-ray transients and immediately identify their counterparts in near-infrared.
The Wide Field X-ray Monitor (WFXM) is the main instrument to search for the transients in the soft X-ray band. WFXM comprises lobster-eye optics (LEO) and pnCCD as an X-ray imager. LEO has a size of 40 mm x 40 mm and a radius of curvature of 600 mm. We are planning to use the LEO manufactured by Photonis Inc. One WFXM module has three by three LEOs, which cover a field of view of 12 deg x 12 deg. The current baseline design is composed of 16 modules to cover ~0.7 sr sky. The candidate focal imager is the pnCCD detector by PNSensor Inc. We will present the current status and prospects of the WFXM.
13093-77
20 June 2024 • 14:40 - 15:00 Japan Standard Time
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HiZ-GUNDAM is a future satellite mission for gamma-ray burst observations. One of the mission instruments is the wide-field X-ray monitor with a field of view (FoV) of ~0.5 steradian at 0.4–4.0 keV, consisting of Lobster Eye Optics (LEO) and pnCCD image sensors. LEOs need to be spatially well-aligned to achieve both of wide FoV and fine position accuracy of < 3 arcmin.
To address this challenge, we explored an alignment method with X-rays and developed an optical frame. This study reports on the evaluation of the optical frame, our alignment method, and x-ray performance of the optical system.
13093-78
20 June 2024 • 15:00 - 15:20 Japan Standard Time
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We have been developing X-ray optics for a fourth FOXSI (Focusing Optics X-ray Solar Imager) sounding rocket experiment, FOXSI-4. We fabricated two types of X-ray optics specified for soft and hard X-ray observations and finally evaluated environmental tolerance required such as random vibration. Additionally, we conducted X-ray irradiation tests at 2-18 keV using a large area beam to evaluate X-ray performances such as FWHM, HPD (Half Power Diameter), and effective area. Consequently, we obtained <5 / <3 arcsec (detection limit) in FWHM, ~16 / ~20 arcsec in HPD and ~18 / ~41 mm^2 in on-axis effective area for both soft and hard X-ray optics, respectively. Additionally, we constructed our original ray-tracing simulator and confirmed that the resultant energy dependence of the effective area is consistent with the expected values. We will report the details and the latest status of our optics.
Break
Coffee Break 15:20 - 15:50
Session 17:
Missions Probe Class Proposals
20 June 2024 • 15:50 - 17:50 Japan Standard Time
Session Chair:
Marco Feroci, INAF - Istituto di Astrofisica e Planetologia Spaziali (Italy)
13093-79
20 June 2024 • 15:50 - 16:10 Japan Standard Time
Show Abstract +
The Decadal Survey on Astronomy and Astrophysics 2020 issued in 2021 by the National Academies delivered strong recommendations for NASA to consider future missions to complement detections of gravitational waves and neutrinos with electromagnetic observations in space, and more generally to sustain its fleet of missions that contribute to the science enabled by multi-messenger and time-domain astronomy. In this presentation we discuss the current technology investments by NASA in this vibrant field, including detector development, infrastructure, suborbital experiments, and small satellites.
13093-80
20 June 2024 • 16:10 - 16:30 Japan Standard Time
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HEX-P is a probe-class mission concept that combines the power of high angular resolution with broad bandpass coverage to provide the necessary leap in capabilities to address the important astrophysical questions of the next decade. HEX-P achieves its breakthrough performance by combining technologies developed by experienced partners and international collaborations. HEX-P will be launched into L1 for a high observing efficiency, and to meet the science goals the payload consists of a suite of three co-aligned X-ray telescopes designed to cover the 0.2 - 80 keV bandpass where accretion is at its peak. The High Energy Telescope (HET) has an effective bandpass of 2-80 keV, and the Low Energy Telescope (LET) an effective bandpass of 0.2-20 keV. The combination of bandpass and high observing efficiency delivers a powerful General Observer platform for a broad science that services a wide community base. The baseline mission is 5 years, with 30% of t
13093-81
20 June 2024 • 16:30 - 16:50 Japan Standard Time
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The Arcus Probe mission addresses a wide range of Astro2020 Decadal and NASA Science Mission Directorate Priority science areas, and is designed to explore astrophysical feedback across all mass scales. Arcus' three baseline science goals include: (i) Characterizing the drivers of accretion-powered feedback in supermassive black holes, (ii) Quantifying how feedback at all scales drives galaxy evolution and large-scale structure, including the tenuous cosmic web, and (iii) Analyzing stellar feedback from exoplanetary to galactic scales, including its effects on exoplanet environments targeted by current and future NASA missions. These science goals, along with a robust General Observer program, will be achieved using a mission that provides a high-sensitivity soft (10-60Å) X-ray spectrometer (XRS), working simultaneously with a co-aligned UV spectrometer (UVS; 970-1580Å). Arcus enables compelling baseline science and provides the broader astronomy community a revolutionary tool to characterize the full ionization range of warm and hot plasmas - including hydrogen, helium, and all abundant metals - Universe, from the halos of galaxies and clusters to the coronae of stars.
13093-82
20 June 2024 • 16:50 - 17:10 Japan Standard Time
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The Line Emission Mapper (LEM) is a Probe mission concept developed in response to NASA’s APEX AO. LEM consists of one science instrument composed of a large area, wide-field X-ray optic and a microcalorimeter X-ray imaging spectrometer. LEM is optimized to observe low-surface brightness diffuse X-ray emission over a 30’x30’ field of view with 1.3-2.5 eV spectral resolution in the 0.2-2.0 keV band. Our primary science will be to map in emission the thermal, kinetic, and elemental properties of the diffuse gas in galaxies, the outskirts of galaxy clusters and the filamentary structures between these clusters, and in the Milky Way star formation regions and Galactic halo, and Galactic and Local Group supernova remnants. LEM will spend ~11% of its five-year prime science mission performing an All-Sky Survey – the first All-Sky X-ray survey at high spectral resolution. The remainder of the time will be divided between the directed science (30%) and competed General Observer science (70%). In this presentation, we will give a mission overview, the directed science that drives the mission design, and the broad scope that these capabilities offer the astrophysics community.
13093-83
20 June 2024 • 17:10 - 17:30 Japan Standard Time
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The Advanced X-ray Imaging Satellite (AXIS) is a Probe-class concept that will build on the legacy of the Chandra X-ray Observatory by providing low-background, arcsecond-resolution imaging in the 0.3–10 keV band across a 450 square arcminute field of view, with an order of magnitude improvement in sensitivity. AXIS utilizes breakthroughs in the construction of lightweight segmented X-ray optics using single-crystal silicon, and developments in the fabrication of large-format, small-pixel, high readout rate CCD detectors with good spectral resolution, allowing a robust and cost-effective design. Further, AXIS will be responsive to target-of-opportunity alerts and, with onboard transient detection, will be a powerful facility for studying the time-varying X-ray universe, following on from the legacy of the Neil Gehrels Swift X-ray observatory that revolutionized studies of the transient X-ray Universe. We present the current status of AXIS, highlighting the prime science objectives driving the AXIS concept and how the observatory design will achieve these objectives.
13093-84
20 June 2024 • 17:30 - 17:50 Japan Standard Time
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STROBE-X is a proposed Astrophysics Probe mission to conduct X-ray spectroscopy of time-variable targets and discovery of new sources. STROBE-X consists of three powerful instruments that provide an order of magnitude improvement in collecting area over previous capabilities for broad energy band, time domain spectroscopy, and a wide field monitor that scans 1/3 of the sky to discover new transients and enable rapid follow-up. STROBE-X will be the next generation high-energy cornerstone for time domain and multi-messenger astrophysics.
Session 18:
Missions III
21 June 2024 • 08:30 - 09:50 Japan Standard Time
Session Chair:
Vadim Burwitz, Max-Planck-Institut für extraterrestrische Physik (Germany)
13093-85
21 June 2024 • 08:30 - 08:50 Japan Standard Time
Show Abstract +
The Focusing Optics X-ray Solar Imager (FOXSI) sounding rocket experiment enables high-resolution hard-X-ray solar observations with high sensitivity using the direct imaging method.
The fourth flight, FOXSI-4, is scheduled to launch in spring 2024, aiming for the first-ever focusing imaging spectroscopic observation of a medium to large solar flare in hard X-rays.
We developed wide-gap CdTe Double-sided Strip Detectors (CdTe-DSDs) for the hard X-ray focal plane detector, which achieved an energy resolution of ~1 keV (FWHM) and a high position resolution of ~ 30 µm with high detection efficiency.
We also developed a new onboard data acquisition (DAQ) system with a Raspberry Pi, an FPGA board SPMU-001, and a SpaceWire interface for controlling all CdTe-DSDs and realizing fast readout of the observation data whose counting rate is estimated to be ~ 5000 counts per second.
We give an overview of the hard X-ray telescope and the development of the DAQ system for the CdTe-DSDs.
13093-86
21 June 2024 • 08:50 - 09:10 Japan Standard Time
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THESEUS is a mission concept proposed in response to the Euroepan Space Agency (ESA) call for medium-size mission (M7) within the Cosmic Vision Programme and currently undergoing a phase A study, competing with other two candidates for a launch opportunity in 2037. The mission is designed to vastly increase the discovery space of the high energy transient phenomena over the entirety of cosmic history. As such, THESEUS is planned to have large synergies with all major operating facilities in the 2030's. In this contribution, I will provide an overview of the mission payload, profile, and plans for the operations. The final selection among the 3 candidate missions within the ESA M7 call, leading to a single mission to be implemented for launch in 2037, is expected at the end of 2026.
13093-87
21 June 2024 • 09:10 - 09:30 Japan Standard Time
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The LargE Area burst Polarimeter (LEAP) is a proposed Compton scattering polarimeter that will, for the first time, measure the level of polarization for a significant number of GRBs with sufficient sensitivity to determine the magnetic field structure, composition, energy dissipation mechanism of GRB jets, and determine the prompt emission mechanism of GRBs. Once approved, LEAP will be deployed as an external payload on the International Space Station (ISS) where it will measure GRB polarization over the energy range from 50–1000 keV, perform GRB spectroscopy from 20 keV to 6 MeV, and self-sufficiently determine the source direction. LEAP is uniquely suited to fill a critical gap in our knowledge regarding GRBs, by exposing the underlying physics that governs astrophysical jets and the extreme environment surrounding newborn compact objects.
13093-88
21 June 2024 • 09:30 - 09:50 Japan Standard Time
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KOYOH is a micro-satellite mission conducted by Kanazawa University. The objective is to explore the origin of the short gamma-ray burst progenitors by observing the X-ray transients associated with gravitational waves. It has two mission instruments. The one is wide field X-ray imager named T-LEX, and the other is gamma-ray burst monitor named KGD. The satellite will be launched in 2023. In this presentation, we summarize the scientific objectives, design and performance of the flight model mission instruments, and the initial in-flight status of the satellite.
Break
Coffee Break 09:50 - 10:10
Session 19:
Missions IV
21 June 2024 • 10:10 - 11:30 Japan Standard Time
Session Chair:
Megan E. Eckart, Lawrence Livermore National Lab. (United States)
13093-89
21 June 2024 • 10:10 - 10:30 Japan Standard Time
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GEO-X (GEOspace X-ray imager) is a small satellite mission to visualize the Earth’s magnetosphere through Solar Wind Charge eXchange (SWCX). SWCX is known as soft X-ray emissions generated by the charge exchange between highly charged-state heavy ions and neutral atoms in the Earth’s exosphere. The GEO-X satellite is aimed to be launched during the upcoming solar maximum and is planned to be injected to a low-latitude orbit which allows visualization of the magnetosphere from outside the magnetosphere. The satellite will carry a light-weight X-ray imaging spectrometer, dramatically improving the size and weight of those onboard past X-ray astronomy satellites.
13093-90
21 June 2024 • 10:30 - 10:50 Japan Standard Time
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BurstCube is a 6U (10 x 20 x 30 cm) CubeSat designed to detect gamma-ray bursts (GRBs) and enable multi-messenger observations, scheduled to launch in early 2024. BurstCube science is informed by the coincident detection of GRB 170817A and gravitational wave (GW) 170817, which confirmed compact binary mergers as progenitors for GRBs. Future coincident detections will also provide important context to the GW measurements - namely constraining the neutron star equation of state and testing fundamental physics, while also probing the origin of GRB prompt emission. Full sky coverage in the gamma-ray regime is needed to increase the likelihood of such measurements. Once in orbit, BurstCube will expand sky coverage while rapidly providing public alerts and localization information to the community using the Tracking and Data Relay Satellite (TDRS) and General Coordinates Network (GCN). This work will describe the current status of the mission, as well as an outline of post-launch operations, performance, and science goals.
13093-92
21 June 2024 • 11:10 - 11:30 Japan Standard Time
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JEDI is a Japanese lead X-ray mission proposal aiming at an hour-level follow up TOO observations with 0.3-79 keV wide X-ray band-width with imaging spectroscopy capability. The mission has a good hard-X-ray effective area combined with low instrumental background, and a good soft-X-ray wide-FOV survey capability. Aiming at a launch in mid 2030s, the mission is designed to provide wide-band spectroscopy of time-dependent high-energy phenomena. The low background and large effective area in the hard X-ray band also make it good at observing diffuse hard X-ray emissions, on which the existing hard X-ray observatories faced some limitations. The 1-degree soft-X-ray FOV will provide survey capability and can be used for monitoring star-clusters and near-by galaxies with optional on-the-fly step maneuver capability to locate flaring targets into the narrower FOV of hard X-ray imager. UV coverage and polarimetry options are also considered.
Session 20:
Gamma and Polirametry I
21 June 2024 • 11:30 - 12:20 Japan Standard Time
Session Chair:
Norbert Meidinger, Max-Planck-Institut für extraterrestrische Physik (Germany)
13093-93
21 June 2024 • 11:30 - 12:00 Japan Standard Time
Show Abstract +
IXPE, the first observatory dedicated to imaging X-ray polarimetry, was launched on Dec 9, 2021 and is operating successfully. A partnership between NASA and the Italian Space Agencey (ASI) IXPE features three X-ray telescopes each comprised of a mirror module assembly with a polarization sensitive detector at its focus. An extending boom was deployed on orbit to provide the necessary 4 m focal length. A 3-axis-stabilized spacecraft provides power, attitude determination and control, and commanding. After 2.5 years of observation IXPE has measured statistically-significant polarization from almost all the classes of celestial sources that emit X-rays. In the following we describe the IXPE in-orbit status as derived by the observation of celestial sources and from the use of the on-board calibration systems reporting on its performance after 2.5 years of operations. We show, also, the main astrophysical results which are outstanding for a SMEX mission.
13093-94
21 June 2024 • 12:00 - 12:20 Japan Standard Time
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Many questions posed in the Astro2020 Decadal survey in both the New Messengers and New Physics and the Cosmic Ecosystems science themes require a gamma-ray mission with capabilities exceeding those of existing (e.g. Fermi, Swift) and planned (e.g. COSI) observatories. ComPair, the Compton Pair telescope, is a prototype of such a next-generation gamma-ray mission. It successfully launched from Ft. Sumner, New Mexico in August 2023. To continue the goals of the ComPair project to develop technologies that will enable a future gamma-ray mission, the next generation of ComPair (ComPair 2) will be upgraded to increase the sensitivity and low-energy transient capabilities of the instrument. These advancements are enabled by AstroPix, a Silicon monolithic active pixel sensor, in the tracker and custom silicon photomultipliers and front-end electronics in the calorimeter. This effort builds on design work for the All-sky Medium Energy Gamma-ray Observatory eXplorer (AMEGO-X) concept that was submitted the 2021 MIDEX Announcement of Opportunity. The team will build a prototype tower and test the integrated system with laboratory sources and in a gamma-ray beam.
Break
Lunch Break 12:20 - 13:40
Session 21:
Gamma and Polirametry II
21 June 2024 • 13:40 - 15:40 Japan Standard Time
Session Chair:
Norbert Meidinger, Max-Planck-Institut für extraterrestrische Physik (Germany)
13093-95
21 June 2024 • 13:40 - 14:00 Japan Standard Time
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The CUbesat Solar Polarimeter (CUSP) is a CubeSat mission to measure the linear polarization of solar flares in the hard X-rays band by means of a Compton scattering polarimeter. CUSP is a project in the framework of the Alcor Program of the Italian Space Agency aimed to develop new CubeSat missions. CUSP is approved for a Phase B study that will last for 12 month starting from the beginning of 2024. We report on the current status of the CUSP mission design, mission analysis and payload scientific performance.
13093-96
21 June 2024 • 14:00 - 14:20 Japan Standard Time
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GRAMS (Gamma-Ray and AntiMatter Survey) is a next-generation proposed balloon-borne/satellite-based mission aimed at high sensitivity MeV gamma-ray astrophysical observations and background-free indirect dark matter search via hadronic antiparticles. The main detector of GRAMS is a meter-scale liquid argon time projection chamber (LArTPC). The adoption of liquid argon as detector material allows us to produce an unprecedentedly large effective area instrument both for cosmic MeV gamma rays of 0.5-20 MeV and antiparticles of dark matter origin. This large effective area, which will exceed 1000 cm2, is necessary for measuring faint gamma-ray signals of nuclear line emissions from energetic phenomena such as supernovae as well as for observing short-duration transient objects including gamma-ray bursts with high photon statistics. In this talk, we present the mission concept and design, the current proof-of-concept studies using prototype LArTPCs, and an engineering balloon flight conducted in 2023.
13093-97
21 June 2024 • 14:20 - 14:40 Japan Standard Time
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The Compton Spectrometer and Imager (COSI) is a NASA funded Small Explorer (SMEX) mission slated to launch in 2027. COSI will house a wide-field gamma-ray telescope designed to survey the entire sky in the 0.2-5 MeV range, providing imaging, spectroscopy, and polarimetry of astrophysical sources. In addition to the main instrument, COSI will fly with a Student Collaboration Project known as the Background and Transient Observer (BTO). BTO will extend the COSI science to lower energies by providing spectral information in the 30 keV–2 MeV range.
Using spectral information from both the COSI and BTO instruments, physics such as the energy peak turnover in gamma-ray bursts, the properties of soft gamma-ray repeaters, and the rates of transient phenomena will be constrained. In this talk, we present on the shared science returnables from the COSI and BTO missions. This will include an overview of the instrument and survey designs, simulations of several transient phenomena as observed with both COSI and BTO, and a final analysis of the event rates expected in the BTO instrument.
13093-98
21 June 2024 • 14:40 - 15:00 Japan Standard Time
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INSPIRE is the world's first satellite in the 50kg-class designed for MeV gamma-ray astronomy. Despite the limited observations in the MeV gamma-ray band since the launch of the COMPTEL satellite in 1991, this energy range is crucial for the study of nuclear gamma-rays, which play a significant role in nucleosynthesis processes.
INSPIRE is equipped with a hybrid Compton-camera system that can simultaneously achieve X-ray and gamma-ray imaging by combining features of Compton and pinhole cameras in a single detector system. It consists of two sensor layers of large-area Silicon Photomultiplier (SiPM) arrays optically coupled with 3D position-sensitive GAGG scintillators. The sensitivity is estimated to surpass that of COMPTEL by one month of measurements.
The structural design of INSPIRE is based on the university satellite HIBARI, launched in 2021, and PETREL, currently in preparation for launch.
The launch is scheduled for 2026. The Engineering Model has been fabricated, and performance test in progress. In this presentation, I will introduce the design and the progress of these performance tests.
13093-99
21 June 2024 • 15:00 - 15:20 Japan Standard Time
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In the MeV band, we can obtain the unique information about nucleosynthesis, diffusion in our galaxy, low-energy cosmic rays, particle acceleration, and so on. However, the detection sensitivity in this band has a large gap compared to that in the other bands due to a huge background contamination. For the future observations, we are developing an electron-tracking Compton camera (ETCC) with the powerful background rejection tools based on the Compton recoil electron tracks. This ETCC has been demonstrated in the last two balloon experiments, and we are now preparing for the next balloon flight SMILE-3 to observe galactic diffuse gamma rays and some bright celestial objects. In this talk, we will talk about the scientific motivation and the preparation of ETCC for SMILE-3.
13093-100
21 June 2024 • 15:20 - 15:40 Japan Standard Time
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The Gamma-Ray Polarimeter Experiment (GRAPE) is a high-altitude balloon experiment designed for polarization studies of transient sources with a long-term goal of observing Gamma-Ray Bursts (GRBs) aboard a series of Long Duration Balloon flights (LDBs). Polarization studies of GRB prompt emission is necessary to constrain existing physics models describing the radiation processes and magnetic field structures of astrophysical jets. GRAPE is a wide field of view (FoV) Compton polarimeter measuring γ-ray polarization in the 50-500 keV energy range with a broad range (20 keV – 3 MeV) for spectroscopy. The novel 3-dimensional geometry of the current design provides GRAPE with Compton imaging in addition to polarization capabilities. The instrument consists of 245 optically isolated SiPM coupled to either high-Z (GAGG:Ce) or low-Z (para-Terphenyl) scintillator arranged in a 7x7x5 cuboid structure. At the center of the scintillator array two low-Z detectors contain a ~25 nCi Co-60 calibration source for onboard calibrations. A test flight of this design was flown on August 27, 2023, from Fort Sumner, NM to validate the scientific capability of the instrument design. We will report on res
Session PS1:
Posters - UV
17 June 2024 • 17:30 - 19:00 Japan Standard Time
13093-101
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
Aspera is a NASA Pioneers Mission designed to measure faint OVI emission around nearby galaxies with unprecedented sensitivity. The SmallSat payload consists of two identical co-aligned spectrographs, both operating in the Far Ultraviolet (FUV) between 1030 -1040 Angstrom. Missions operating at FUV wavelengths are particularly sensitive to contamination, as short wavelengths are easily scattered and absorbed by contaminants deposited on payload optical surfaces. A strict contamination control plan is critical to avoiding a severe loss in FUV throughput. Aspera contamination control efforts have been tailored to fit within the scope of a sub-Class D mission, a challenge that has become increasingly relevant as advances in FUV optics/detectors drive an uptick in smaller platform, contamination sensitive UV payloads. Contamination monitoring is used to audit the cleanroom environment, avoid outgassing contaminants under vacuum, and assess contaminant levels on payload optics. We will present contamination monitoring measurements made throughout the payload build and discuss protocols implemented for minimizing contamination-related performance degradation.
13093-102
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Aspera is a NASA Astrophysics Pioneers SmallSat project, designed to study galaxy evolution by detecting warm-hot coronal galaxy halos through spectroscopic OVI emission observation at 1032 Å. Using two Rowland-Circle spectrographs with off-axis parabolas and toroidal gratings sharing a Micro Channel Plate detector, the mission faces the challenge of achieving a low instrument scattered light background. This paper details a comprehensive analysis of straylight in the instrument, presenting a two-staged baffle design to minimize background. The first stage optimizes vane geometry using a first-order algorithm, preventing out-of-field straylight from reaching the detector. The second stage strategically places a shared baffle structure to block unwanted light. Coated with Acktar Magic Black, the baffles successfully meet stray light suppression requirements in simulation studies, demonstrating the effectiveness of the proposed design. This work provides valuable insights for optimizing instrument design in missions with stringent background requirements.
13093-103
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Aspera is a NASA Pioneers Mission designed to reach ultra-low surface brightness limits in the Far Ultraviolet (FUV). The SmallSat payload consists of two identical spectrograph channels, both sharing a single detector and operating between 1030 -1040 Angstrom. The FUV sensitivity of this mission hinges on the availability of high QE, low background, photon-counting detectors. Aspera uses a microchannel plate detector (MCP) designed and manufactured by Sensor Sciences. The detector is a small format, flat MCP stack with a CsI photocathode. A custom cross-delay line anode has been designed to optimize the resolution in two separate active areas on the detector, one from each spectrograph channel. We present characterization and testing performed at the University of Arizona with the Aspera flight electronics following the delivery of the flight model detectors.
13093-104
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The balloon-borne UV telescope Faint Intergalactic Red-shifted Emission Balloon (FIREBall-2) was launched from Fort Sumner, NM on September 25, 2023, for its second attempted flight. The flight was unexpectedly terminated at ~10 hours due to a mechanical issue, and very little science data was obtained; however, this short flight provided an excellent opportunity to test the in-flight communications system. Testing the communication system pre-flight was challenging, and an accurate sense of signal reception and communication errors expected during flight could not be obtained. From launch to descent, very few data packets were dropped or corrupted. Had the flight continued for the expected duration, the success up to early termination gives confidence that the communications systems would have continued to meet our expectations. While this test was highly successful, some areas for improvement were identified and will be addressed before FIREBall-2’s next flight.
13093-105
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Faint Intergalactic Medium Redshifted Emission Balloon (FIREBall-2) is a UV multi-object spectrograph exploring the CGM of galaxies at low redshifts (0.3 < z < 1.0). The science detector is a large-format 2k x 1k electron multiplying (EM) CCD, optimized for FIREBall-2’s bandpass in the UV. The technology involved in UV photon-counting CCDs is slated for use on next-generation Great Observatories, like Habitable Worlds Observatory and the Roman Space Telescope. FIREBall-2 plays a critical role in increasing the TRL of these next-generation UV detectors; this will provide feedback for future proposals that require space-qualified detectors.
We will present an overview of the FIREBall-2 detector system, discuss the motivations for the upgrades since the 2018 campaign, the progress made on implementing them, and the ground performance including read noise, conversion gain, dark current, CIC, CTE, and EM gain of the final system for the FIREBall-2 launch in September 2023 in Fort Sumner, NM.
13093-106
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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FIREBall-2 is a Balloon-Borne UV telescope designed to observe faint UV emission from the circumgalactic medium around low redshift galaxies (z ~ 0.3 - 1.0). FIREBall-2 employs a 1m telescope with a multi-object spectrograph, custom-designed slit-masks and a delta-doped EMCCD detector. FIREBall-2 achieves steady 1-2” pointing with a CNES-provided coarse guidance system complemented by a fine guidance system which provides real time, on-sky feedback with an sCMOS camera embedded within the spectrograph enclosure. The guider system provides a live video stream, computes translational and rotational offsets and sends high rate (30 Hz) gondola pointing error corrections, while also handling slit mask selection and in-flight optimization of the image focus and PSF. We review the current state of the system after testing and use during FIREBall-2’s 2018 and 2023 campaigns and discuss its performance, challenges and development of its hardware and software functions ahead of its next flight campaign.
13093-107
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Faint Intergalactic-medium Red-shifted Emission Balloon (FIREBall-2) is a joint NASA/CNES-funded balloon-borne UV telescope to map faint UV emission from the circumgalactic medium around low redshift galaxies. The initial September 2018 flight encountered challenges, including a balloon breach and subsequent damage during landing, impacting the two large telescope mirrors and the critical focal corrector. Likely due to landing shock, the focal corrector experienced misalignment beyond tolerance, necessitating re-evaluation and realignment. This paper outlines a comprehensive approach to realigning the focal corrector using a computer-generated hologram (CGH) and a Zygo interferometer for feedback. The CGH enables precise alignment corrections in various degrees of freedom, while interferometer feedback aids in reducing aberrations. The paper details the methodology for optical alignment, surface measurement, and performance evaluation of the focal corrector, emphasizing its successful integration into the FB-2 spectrograph in early 2023 for the upcoming September 2023 flight.
13093-108
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Aspera is a NASA Pioneers SmallSat mission designed to detect and map the O VI emission (103.2 nm) through long-slit spectroscopy in the halos of nearby galaxies for the first time. The spectrograph utilizes toroidal gratings with multilayer coatings of aluminum, lithium fluoride, and magnesium fluoride that optimize their throughput in the extreme ultraviolet EUV waveband of 103 to 104 nm. We discuss the grating verification test setup design, including optical alignment and reference measurement setup. We also present the result of grating efficiency simulation using the target grating groove profile and the multi-layer coatings.
13093-109
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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A small UV imager, named HI (Hydrogen Imager), is currently under development to observe the hydrogen coma of a long-period comet. The instrument will be on board one of the probes for the ESA's Comet Interceptor mission, scheduled for launch in 2029. The optical design and detector of HI are optimized for observing hydrogen Lyman-alpha (wavelength 121.6nm) with dimensions smaller than 10cm x 10cm x 25cm and power consumption less than 9W. This presentation will provide an overview of the current development status, focusing on the activities related to the engineering model (EM).
13093-110
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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In anticipation of a move to a seventh Lifetime Position on the FUV channel of the Cosmic Origins Spectrograph (COS) in 2025, we have conducted exploratory work to model the instrument performance over the full range of possible positions for the spectra on the detector. This effort includes (1) optical modeling of the spectrograph; (2) creating simulated science spectra and evaluating the resolving power and other spectral properties at a range of positions; (3) evaluating the detector properties at potential lifetime positions while considering mechanical limitations of the hardware; and (4) reserving sufficient space for later Lifetime Positions. We have used this information to formulate preliminary plans for moving to the next position, which includes identifying which observing modes should be adjusted, and providing our initial thoughts on future Lifetime Positions.
13093-111
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The field of ultraviolet (UV) spectroscopy has long been instrumental in unravelling the mysteries of our universe, shedding light on the fundamental processes governing celestial objects and terrestrial phenomena. In this context, the development of advanced spectrographic instruments is pivotal to enhancing our understanding of these spectral signatures. Recent years have witnessed significant progress in UV spectroscopy, driven by advancements in technology and materials science. One crucial element of UV spectrography is the optical slit, which plays a pivotal role in determining the spectral resolution and overall performance of a spectrograph. Traditional fabrication methods for optical slits often face limitations in precision, throughput, and reproducibility.
13093-112
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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ULTRASAT is a spaceborne near UV telescope with an unprecedentedly large field of view (200 squared degrees) and UV sensitivity. The mission, led by the Weizmann Institute of Science and the Israel space agency in collaboration with DESY (Helmholtz foundation, Germany) and NASA (USA), is expected to be launched to a geostationary orbit in late 2026. The mission payload is currently going through assembly, integration and testing, with all critical elements manufactured and tested. In the following talk I will describe in detail the various challenges encountered, those we expect to encounter during operation, and our mitigation plan. I will emphasize topics such as cleanliness and contamination, optics qualification and stray light testing. Finally, I will present the expected performance based on as-built data.
13093-113
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present the progress of the design of the Spectroscopic Ultraviolet Multi-object Observatory (SUMO) Prototype and its current development, building, and testing. The SUMO Prototype is part of the technology maturation program of SUMO, a mission concept designed for small and medium-sized satellite platforms, and will be the first time a DMD-based instrument is deployed in space. Because the SUMO Prototype will be deployed as a secondary payload, the spectrograph is designed for completely autonomous operation in the near-ultraviolet (NUV) regime. The SUMO Prototype consists of an 8 cm Cassegrain telescope and a digital micromirror device (DMD)-based multi-object spectrometer (MOS), with parallel imaging and spectroscopic channels. As part of this work, we also developed a custom DMD controller, which is suitable for operation in the space environment. This controller works with a custom-developed object selection code, which performs multi-object spectroscopy in real-time. The SUMO Prototype is tentatively scheduled for flight in 2025 aboard the INFUSE sounding rocket.
13093-114
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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SPRITE (Supernova Remnants, Proxies for Reionization Testbed Experiment) is a 12U CubeSat mission funded by NASA and led by the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado, Boulder. The payload will house the first sub-arcminute resolution Far-UV long-slit spectrograph with access to the Lyman UV, enabled by new enhanced lithium fluoride coatings and an ultra-low-noise photon-counting microchannel plate (MCP) detector. The scientific mission has two main components with distinct observing modes: for low-redshift galaxies we will operate the MCP detector in photon-counting mode and obtain 2D spectra with a single pointing, while for nearby star forming regions and supernova remnants we will operate the MCP in an accumulation / integration mode and collate multiple pointings of the long slit to create 3D spectroscopic cubes. SPRITE will also take weekly calibration data to characterize the degradation of the coatings and detector. In this proceeding we present these observing modes along with the data acquisition and processing pipeline required to enable scientific analysis on the ground.
13093-115
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Aspera is a NASA Astrophysics Pioneers SmallSat mission consisting of twin Far-UV spectrographs designed to study diffuse OVI emission (λrest = 103.2 nm) from the warm-hot phase of coronal gas in the halos of nearby galaxies. The two identical spectrographs are optimized to operate in the 103-104 nm share a Cross-delay line (XLD) Microchannel Plate (MCP detector. The payload is currently being assembled at University of Arizona, the payload is expected to integrate into the spacecraft by late 2024-early 2025. In this paper we provide an overview of the on-going ground calibration and performance verification activities of the instrument and the planned in-orbit calibration activities during mission operations. During these calibration, we will measure the spectral, spatial resolution, photometric and astrometric performance of the instrument. These measurement will be used to derive the wavelength solution, effective area, in-orbit noise and pointing models. These results will be applied in the data pipeline for calibration of the science data..
13093-116
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Feedback from massive stars through their host galaxies is a crucial driver of galaxy evolution. Massive stars also emit ionizing radiation, a fraction of which escapes into the intergalactic medium. The Supernova remnants/Proxies for Reionization and Integrated Testbed Experiment (SPRITE) is a 12U CubeSat that will observe these processes via its imaging spectrograph. We present the results of ground testing of the flight SPRITE instrument and characterize its projected on-orbit performance. We also demonstrate the capabilities of SPRITE’s unique technological developments, including advanced UV mirror coatings and a low-background microchannel plate detector, providing flight heritage for Habitable Worlds Observatory (HWO) and future missions.
13093-117
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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ULTRASAT is a near-ultraviolet imaging satellite with a wide field of view (200 square degrees) and a planned 2026 launch. It is an international partnership led by Israel (Israel Space Agency & Weizmann Institute of Science) in partnership with the United States (NASA) and Germany (DESY). ULTRASAT will provide high cadence observations and rapid target-of-opportunity response, providing a powerful capability for time-domain and multimessenger astrophysics (TDAMM), and will have scientific applications from solar system studies to cosmology.
This presentation will explore the ULTRASAT science drivers and capabilities; NASA's roles in the ULTRASAT project (including the launch, an archive, and broad science involvement); and how ULTRASAT fits with NASA scientific priorities.
13093-118
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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SING is a near ultraviolet (NUV) spectrograph designed to operate from 1400 Å to 2700 Å with a spectral resolution of around 2Å. The primary science objective is to study the physical conditions in extended regions of the sky like the ISM, supernova remnants (SNR) and planetary nebulae. SING has a telescope with a primary aperture of 298mm, which collects and feeds to a long-slit UV spectrograph. The spectrograph employs a dumbbell slit and a holographic flat-field-corrected concave grating to image the slit at different wavelengths onto the detector. SING employs a photon-counting detector based on an image intensifier and CMOS camera. The spectrograph is intended to map nebulae and other extended objects at moderate spatial and spectral resolution in the NUV from a stable platform of the space station -- Chinese modular space station (CSS). In this work, we present the instrument's optomechanical alignment and assembly, followed by testing and calibration.
13093-119
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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We discuss the final assembly, integration, and testing of the Star-Planet Activity Research CubeSat. SPARCS is a 6U CubeSat mission designed to monitor the dual-channel, far-UV (151-176 nm) and near-UV (266-310 nm) photometric activity of nearby low mass stars to advance our understanding of their evolution, activity, and the habitability of surrounding exoplanets. This paper details the assembly of the SPARCS instrument and the testing process to characterize and validate the performance of the payload prior to spacecraft integration. To test SPARCS, we have established a customized CubeSat AIT laboratory and thermal vacuum chamber at ASU equipped to handle CubeSats requiring meticulous contamination control for work in the FUV. After a brief overview of these facilities and the testing plan, we will detail the methods and data used to verify the performance of SPARCS and generate calibration products to reduce raw flight data to high-quality science products. The result will be the delivery of the first highly sensitive FUV astrophysics CubeSat which will inform exoplanet environments and future observations of these systems by facilities like the Habitable Worlds Observatory.
13093-120
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Start-Planet Activity Research CubeSat (SPARCS) is a NASA-funded mission led by Arizona State University, devoted to characterizing the UV emission of low-mass stars. During the course of its one year mission, SPARCS will observe close to 20 low-mass stars, with the goal of understanding their short and long-term UV variability. SPARCS is expected to be ready for launch in late 2024.
Here we present the SPARCS calibration plan, which makes use of observations of very stable white dwarfs to achieve 10% photometric accuracy in both the near- and far-UV bands (Pivot wavelengths 162 nm, 293 nm). SPARCS’ payload is a 10-cm telescope paired with two delta-doped CCDs. While the system is only weakly sensitive in the infrared, the target stars are very bright at long wavelengths. This requires careful correction for out-of-band emission. The system is being fully characterized on the ground to provide supporting data for the calibration.
13093-121
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Carruthers Geocorona Observatory is a NASA Heliophysics mission designed to study the variability of Earth’s hydrogen exosphere. Launching in 2025, the Carruthers Geo-Coronal Imager (GCI) will observe the exosphere at Far Ultraviolet wavelengths from an Earth-Sun L1 vantage point. The GCI consists of two co-aligned imagers that simultaneously provide both wide field observations entire exosphere, in addition to high spatial resolution observations near the Earth’s limb. The optical prescription for both the narrow field imager (NFI) and wide field imager (WFI) is discussed, including critical analyses that were performed during the design phase of the project. A deterministic alignment approach was adopted to verify performances of the imagers at visible wavelengths prior to verification in the vacuum ultraviolet. The details of this alignment plan, along with opto-mechanical considerations and requirements are discussed in detail. Finally, we discuss the imaging performance of the system in the ultraviolet utilizing a ground calibration facility previously developed for another NASA spaceflight mission.
13093-122
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The CASTOR mission is a wide-field, nearly diffraction-limited, 1m-diameter space telescope that is under development by the Canadian Space Agency. Although the telescope optimized for wide-field imaging surveys at UV/blue-optical wavelengths, it also features low- and medium-resolution spectroscopic capabilities over the 150 to 400 nm region, and precision photometers for observations of transiting exoplanets. This presentation will review the mission design, including spacecraft and payload layout, telescope opto-mechanical design, focal plane arrays and spectroscopic instrument packages, thermal control, altitude and data handling, launch plan, orbit maintenance, communications, electronics, and ground support. The talk will also describe the mission development plan and summarize ongoing work designed to increase technology readiness levels associated with several key mission elements, including the optical design, focal plane array, CMOS detectors, and ultraviolet multi-object spectrograph.
13093-123
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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A wide-field UV imaging capability is missing in this era of high cadence astronomy even though it can revolutionize our understanding of the transient universe. The recent advancement in UV technologies especially in detector and coating enables the realization of high-throughput small form factor UV payloads for specific science goals. Here we discuss the conceptual development of compact UV imaging payloads for transient observations.
13093-124
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The characterization of the Microchannel plate detector (MCP) of the Far Ultraviolet channel implemented in the imaging instrument on board the WSO-UV observatory is presented. The campaign of qualification tests and the analysis of the results (carried out by the manufacture PHOTEK together with a team from Universidad Complutense de Madrid) cover technical aspects such as quantum efficiency, photon counting uniformity, count rate linearity, spot uniformity, temporal stability or spatial uniformity.
13093-125
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Astro2020 Decadal Survey for Astrophysics recommended as its top priority a mission, now named the Habitable Worlds Observatory (HWO), to observe and determine the habitability of 25 Earth-like planets as well as providing advanced capabilities to enable transformational astrophysics. The latter of these charges focuses on instrumentation that will likely deliver wide field visible band imaging and similarly wide field multi-object spectroscopy in the ultraviolet. This talk will address preparations under way at NASA Goddard to deliver the capabilities needed for the ultraviolet spectrograph to perform at the levels necessary to achieve these goals.
NASA Goddard brings to the table the marriage of mirror coatings that can deliver reflectivity down to 100nm combined with the necessary uniformity to allow 10^10 contrast coronagraphy, the development of next generation electrostatically controlled microshutter assemblies that can be 2-side butted to deliver arrays large enough to address the fields of view envisioned, and the development of transition edge sensor (TES) devices that can provide noise-less measurements in the ultraviolet.
13093-126
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Pollux is a project of UV spectropolarimeter proposed as a European contribution for the planned NASA-led Habitable Worlds Observatory. It comprises of four channels. Three of them are operating in the near-UV, medium UV, and visible range, each representing an echelle spectrograph with a birefringent polarimeter. It is possible to reach the resolving power of R130 000 with the maximum throughput of ~11% in the near UV (236-472 nm) and R95 000 with ≤5% transmission in the medium UV (118-236 nm). A fourth channel for the far-UV below Lyman-alpha is studied with a different design. Finally, we provide an overview of the key science goals and the technological risks.
13093-127
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The near-ultraviolet wavelength range contains a valuable Ozone absorption feature for characterizing the atmospheric composition of Earth-like exoplanets. Both the LUVOIR and HabEx decadal mission concept studies baselined instrumentation for obtaining photometry of directly imaged exoplanets down to wavelengths of 200 nm. Both of their proposed implementations present challenges: in the case of the HabEx starshade occulter, a separate spacecraft is required; in the case of a UV channel within the main coronagraph instrument, non-UV-optimized optics limit the performance. Yet, the science requirements allow the relaxation of some of the trades of a dedicated near-UV coronagraph. Here we present the preliminary design of a standalone UV coronagraph instrument for the Habitable Worlds Observatory concept based on the science requirements. We describe the trades and rationale behind the decision of separating the UV coronagraph from the main instrument and show the evaluation of several coronagraph designs in the UV. We assess the effect of polarization aberrations and describe potential UV detectors and wavefront sensing and control strategies.
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Spectr-UF (Spectrum UV, another name of the mission is World Space Observatory - Ultraviolet) is a space observatory designed to obtain images and spectra of objects of the Universe in the ultraviolet part of the electromagnetic spectrum (115-305 nm) inaccessible to ground-based instruments. This is the next in a series of astrophysical projects in the Federal Space Program of Russia. In a sense, Spektr-UV is an analogue of the Hubble Space Telescope (NASA) and will replace it in orbit.
The main instrument is the T-170M telescope with a main mirror diameter of 170 cm. It is equipped with scientific instruments: a Spectrograph Unit (BS) and a Field Camera Unit (BCP). The observatory will operate in a circular geosynchronous orbit. If the necessary funding is received, the observatory will be ready for launch in 2029. A current status of the mission will be presented.
13093-129
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Far- and Lyman-Ultraviolet Imaging Demonstrator (FLUID) is a
rocket-borne multi-band arcsecond-level ultraviolet (UV) imaging
instrument covering four bands between 92 -- 193 nm. FLUID will
observe nearby galaxies to find and characterize the most massive
stars, the primary drivers of the chemical and dynamical evolution of
galaxies, and the co-evolution of the surrounding galactic
environment. The first telescope to be fabricated and aligned is the
short wavelength channel, F110M, covering 92 -- 115 nm. Each FLUID
telescope is a Cassegrain in which each optic is coated with a
reflective bandpass filter. The imaging requirement for each telescope
is to resolve objects with an angular scale of 4.2'' which corresponds
to a physical scale of ~100 parsecs for proposed FLUID targets, low z
galaxies. We present the optical alignment method and characterization
resulting in a 2.2" full width at half maximum point spread function,
meeting the FLUID imaging requirement with substantial margin.
13093-130
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Field Camera Unit (FCU) is one of the main scientific instruments of the Spektr-UV space mission. The main task of the BCP is to obtain images of astronomical objects in several spectral ranges. For this purpose , three channels are provided in the design of the FCU: vacuum ultraviolet (VUV) channel (115-176 nm) with high
spatial resolution, equipped with an MCP receiver with a CsI photocathode; near ultraviolet (NUV) channel (150-320 nm) with high spatial resolution, equipped with an MCP receiver with a GaN photocathode; near ultraviolet and optical band channel (UVO) (180-1000 nm) with a 4.5 x 4.5 arc min field of view and CMOS receiver. The MCP receivers of the VUV and NUV channels are sun-blind (sensitivity in the optical range is 3-8 orders of magnitude less than in the ultraviolet). In addition to the mode of obtaining images using light filters, a low-resolution field spectroscopy mode is provided.In addition, the optical scheme allows to implement the coronograph mode according to the scheme Lio and polarimeter mode. If there is a request from the scientific community, the list
of filters and the parameters can be modified.
13093-131
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Ultraviolet Explore (UXEX) mission is a wide-field two band imager with a long multi-width slit spectrometer to study the dynamic ultraviolet universe. We present the telescope optical design that provides a continuous 5.0deg x 3.5deg FoV that achieves an rms spot radius of <10 microns. The optical design is a compact unobstructed freeform F/2.7 Three Mirror Anastigmat (TMA) with a 75cm virtual entrance aperture. The all-reflective design is driven to support imaging into the far UV down to 115 nm. The telescope provides light to three instrument channels: a NUV imager (200 - 260 nm), a FUV imager (130 - 190 nm), and a long-slit spectrometer operating over the entire wavelength range (115-265 nm). The spectrometer is an all-reflective re-imager based on an Offner-Chrisp design where the secondary convex mirror is the dispersing element. The spectrometer has a 2deg long slit length with three discrete slit widths of 2", 4", and 8" wide. With a 2" slit width, the spectrometer will have a spectral resolving power of 1400-3200 from 115-265 nm wavelength range.
13093-132
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Despite their success in cosmology, details about the progenitor systems of type Ia supernova (SNe Ia) remain elusive. The UV is one of the most promising wavebands to provide breakthroughs in the physics of SNe Ia. Here we present a mission concept to study SNe Ia from the bluest optical wavelengths through the far-UV providing constraints on the presence of helium in the ejecta, near-UV excesses due to non-degenerate companion donor stars, and UV data to calibrate low redshift training samples for cosmological analyses. This mission will pave the way for the future of time-domain followup from small satellites.
13093-133
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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This paper introduces a mission concept focused on investigating the composition of the interstellar medium (ISM) in the Milky Way and nearby Local Group Galaxies. It emphasizes the prominent ultraviolet (UV) extinction feature at 2175 Å observed in reddened OB stars and proposes carbonate grains as potential carriers. The mission employs UV spectroscopic instruments to map the spatial distribution of extinction features, leveraging recent advancements in coating and detector technologies for high throughput instruments in small form factors. The study outlines an instrument concept, observation strategy, and UV sky simulation for both balloon-based and small satellite-based platforms dedicated to the detailed exploration of UV extinction characteristics.
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CASTOR, for the Cosmological Advanced Survey Telescope for Optical and Ultraviolet Research, is a wide-field space telescope that is under active development by the Canadian Space Agency (CSA). This 1m telescope will produce panoramic imaging of the UV/optical (150-550 nm) sky delivering HST-like image quality over a wide field of view (0.25 sq. deg.), in three filters simultaneously. CASTOR will be optimized for wide-field surveys, although the telescope may also feature low- and medium-resolution spectroscopic capabilities over the 150 to 400 nm region. The poster will describe CASTOR’s unique capabilities within the astronomical landscape in the coming decade, and present highlights from a recently completed Phase 0 study that defined the science mission, including 14 “Legacy Surveys” that span a wide range of fields: including Dark Energy and Weak Lensing; Time Domain and Multi-messenger Astronomy; Galaxy Evolution and AGNs; Star Formation and more. The poster will also show the synergies between CASTOR and other facilities like LSST, Euclid and Nancy-Grace Roman Telescope, focusing on the future contributions of CASTOR to the primary probes of these cosmological surveys.
13093-135
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Nox is a 12U CubeSat mission concept designed to characterize the Lyman-UV (LUV) and Far-UV (FUV) background across the entire sky. Despite the growing interest in LUV/FUV observations in orbit, the spectral and spatial distribution of the LUV/FUV background remains critically understudied. Without knowledge of background radiation, planning a future mission for detecting faint diffuse emissions becomes challenging. The Nox mission concept has been developed to bridge this gap by characterizing the background radiation in the LUV/FUV. Utilizing state-of-the-art UV coating, grating, and detector technologies, Nox aims to deliver unprecedented foundational data in the LUV/FUV landscape through spectroscopic all-sky observation in the 90-140 nm wavelength range using a wide-field, low spectral resolution spectrograph with a 2.5 degrees by 90 arcsec field of view and R~80. In this presentation, we describe the conceptual payload design of Nox, along with the baseline optical design, detailing the expected diffuse background sensitivity in orbit.
13093-136
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Our current understanding of cosmology is largely shaped by Type Ia supernovae (SNe Ia), the detonations of carbon-oxygen white dwarves (WDs). SNe Ia are powerful standard candles due to their uniform peak luminosities which decay predictably. SNe Ia progenitor system architecture is highly debated, as none have been observed pre- and post-detonation. Within the first few days after detonation, critical progenitor signatures are preserved in the ultraviolet (UV) bandpass. We present the optical design of UVIa, a proposed 12U CubeSat capable of simultaneous measurements in optical, near-UV, and far-UV channels. The UV channels utilize off-axis parabolic and fold mirrors to image onto a CMOS detector. The optical channel uses on-axis parabolic and fold mirrors, a filter slider, and a separate CMOS detector. We discuss design trades and potential descopes. The optical design of UVIa enables early-time observations of SNe Ia and serves as a pathfinder for future UV transient telescopes.
13093-138
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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JAXA recently selected LAPYUTA (Life-environmentology, Astronomy, and PlanetarY Ultraviolet Telescope Assembly) as a candidate for JAXA's Small Scale Program No. 6 to be launched by Epsilon in ~2032. We will accomplish the following four objectives: #1 Solar System, #2 Exoplanets, #3 Galaxies, #4 the origin of heavy elements. To achieve these scientific objectives, LAPYUTA aims to carry out spectroscopy with a large effective area (>300 cm2) and a high spatial resolution (0.1 arc-sec) and imaging in far ultraviolet spectral range (110-190 nm). A high dispersion spectrograph with a spectral resolution of < 40000 is required, especially for observing exospheres of terrestrial (Earth-like) exoplanets. We are considering the design of the Spectrograph with High dispersion Echelle grating for the Terrestrial (exo-)planetary Atmosphere (SHETA) as an instrument. In this presentation, we introduce the scientific objective and the conceptual design of the SHETA instrument.
13093-139
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Life-environmentology, Astronomy, and PlanetarY Ultraviolet Telescope Assembly (LAPYUTA) mission aims to carry out spectroscopy with a large effective area (>300 cm2) and a high spatial resolution (0.1 arc-sec) and imaging in far ultraviolet spectral range (110-190 nm) from a space telescope. The main part of the science payload is a Cassegrain-type telescope with a 60 cm-diameter primary mirror. Two main UV instruments are installed on the focal plane of the telescope: a spectrograph and a slit imager. Here we present the LAPYUTA concept design, the overview of the spacecraft and instruments, and the updated status of technology developments.
13093-140
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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SOLAR-C is a Japanese solar physics mission with contributions from the United States and European countries. It features the EUV High-Throughput Spectroscopic Telescope (EUVST) for EUV spectroscopy in a wide temperature range (10,000 to 20 million degrees). The optical system's innovation omits an aperture filter, using only a 28 cm off-axis parabolic primary mirror and a diffraction grating assembly composed of two different gratings, resulting in an effective area ten times larger than the Extreme Ultraviolet Imaging Spectrometer on Hinode. This design offers exceptional spatial (0.4 arcseconds) and temporal (1-second) resolution for EUV-UV imaging spectroscopy across a broad wavelength range (170-212 Å, 464-522 Å, 558-610 Å, 719-847 Å, 928-1043 Å, 1115-1221 Å) within a 100x100 arcsecond field of view. A manufacturability-focused trade-off study successfully relaxed the specifications of one grating. This presentation reports the latest optical design, accounting for component constraints, sensitivity analysis, optical performance alignment, and the error budget.
13093-141
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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We propose Global Coronal Diagnostic Extreme Ultraviolet Imaging Spectrometer, which is an imaging spectroscopy with several distantly-separated slits for the measurement of the global coronal spatial and spectral information with high-cadence in spectral range of 18.3–19.8 nm.
13093-142
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The science goal of this proposal is to determine the system-level evolution of fine-scale (0.05 RE) density structure of the Earth's plasmasphere on 1 to 2 minute time scales. Fine-scale cold plasma structure can exert a critical influence on wave and particle dynamics of the magnetosphere and ionosphere.
To achieve the project science goal, we propose to develop the High Resolution Plasmasphere Observatory (HRPO), a prototype wide-field extreme ultraviolet (EUV) camera with order-of-magnitude improved spatial and temporal resolution compared to any previously flown plasmasphere imager. The IMAGE EUV imager featured a large (~30º) field-of-view, but a relatively poor (~0.6º) spatial resolution. IMAGE EUV was limited by a detector obscuring most of the entrance aperture (reducing throughput and design flexibility). IMAGE EUV included a spherical-surface detector that was expensive and difficult to manufacture. Improvements in reflective coatings, optical surface manufacturing, and detector sensitivity allow for a new two-mirror off-axis optical design with a flat focal surface.
13093-143
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Spektr-UF Space Observatory is considered to be the only large instrument planned for the next decade
that will continuously receive data in the far and near UV wavelength ranges. A necessary component of the observatory for planning and implementing a scientific program (preparation of applications and preparation
of an observation program) is a special software that allows to evaluate the possibility of registering a signal from an astronomical object of interest. In preparation for the launch of Spektr-UF, the first
version of an exposure time calculator was created with the ability to work via a web interface.
The report presents the main features of the Spectr-UF exposure time calculator. Based on real examples, the possibility of implementing photometry and spectroscopy of point and extended sources
using various scientific instruments of the observatory is discussed. Further plans for the development of this exposure calculator are also discussed.
13093-313
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
Multi-object and integral field spectroscopy are enabling technologies for the next generation of space telescopes, including upcoming flagships like the Habitable Worlds Observatory and beyond. A promising technology to perform spatially multiplexed spectroscopy is the digital micromirror device (DMD), a commercially available array of small mirrors, which can be used for object selection, as well as more complex observing modes. Building on the technology maturation performed during previous NASA programs, we have developed the Supernova and Stellar Feedback Rapid-Acquisition Spectrograph (SASAFRAS) – an advanced multi-object and integral field spectrograph for the NUV regime (200 – 400 nm), deployed on the SuperBIT long duration balloon platform. SASAFRAS is designed to carry-out two scientific campaigns: 1) spectroscopic follow-up observations of supernova (and other bright transients), within minutes after their discovery; and 2) a spatially resolved survey of nearby star forming galaxies and their environments. SASAFRAS will achieve a spectral resolution of R~1000, over a 20 arcminute diameter field of view, with a spatial resolution of ~1 arcsec.
Session PS2:
Posters - UV Technology
17 June 2024 • 17:30 - 19:00 Japan Standard Time
13093-145
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The Ultraviolet Imager (UVI) onboard the ESA-CAS Solar wind Magnetosphere Ionosphere Link Explorer (SMILE) joint mission is a CMOS-based ultraviolet camera developed for imaging Earth's northern auroral regions over the 160-180 nm UV waveband with a 10° × 10° field of view. Central to the instrument, four thin film-coated mirrors guide light into its detector and ensure most of the signal filtering, crucial to achieve a high out-of-band rejection and limit contributions from solar diffusion, dayglow and unwanted atomic spectral lines.
Here we present the mirror spectrally selective reflective coating which is based on an interferential MgF2/LaF3 multilayer stack deposited by ion-assisted electron-beam evaporation. Its reflectivity maximum is above 85% and the wavelength at which it occurs is adjustable within 1 nm, whereas the out-of-band reflectivity between 120 nm and 155 nm and between 200 nm and 1100 nm remains below 6% on average.
The coating has been space qualified (thermal cycling under vacuum, radiations, UV exposure…) and shows stable performances in conditions representative of the instrument operation environment.
13093-146
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
Here, we report the development of an ultra-miniature high-sensitive near UV spectrometer to determine the abundance or the upper limit of the water in the lunar atmosphere and investigate the processes that control its distribution and variability. Heterodyne OH Lunar Miniature Spectrometer (HOLMS) is based on the Michelson design Spatial Heterodyne Spectrometry (SHS) technique, a novel approach for high R in a compact, low-cost, low-mass, low-power architecture. HOLMS is designed to observe Hydroxyl (OH) molecules in the lunar exosphere in 311-317 nm and 0.1 nm spectral resolution. OH radicals are key lunar water surrogate molecules produced during solar UV-light dissociation; therefore, measuring it reveals critical information about the lunar water cycle and resources.
Acknowledgments: This work has been conducted at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA: copyright 2024, California Institute of Technology. Government sponsorship acknowledged.
13093-147
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
There are currently no high-resolution, wide wavelength range spectropolarimeters in the UV domain. This represents a critical gap in our observational capabilities. Overcoming this challenge holds the promise of opening up new frontiers in the study of celestial objects, from star-planet interactions to cosmology.
The design of the POLLUX spectropolarimeter for the HWO mission comprises four channels in the visible, near-UV, mid-UV, and far-UV ranges. While MgF2 will be used for polarimeters in the former three, the challenge arises in the far-UV range (100-120nm), where the absence of known transparent birefringent glasses poses a substantial hurdle.
The solution lies in the development of a new type of spectropolarimeter – the reflective FUV polarimeter. After a first study conducted several years ago, the goal of this work is to improve the TRL of this new kind on spectropolarimeter. This article describes the proposed design of the FUV polarimeter for HWO, the optimisation process using the Mueller calculus, as well as the ongoing prototyping and tests conducted.
13093-148
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
For the next generation of large space telescopes, imaging in the UV band will be of high importance. UV optimisation technologies and high-performing CMOS imaging sensors will therefore be essential for these missions to be able to fulfil their science requirements. The CASTOR mission, a 1m UV space telescope project, will be utilising the large format CIS303 and CIS120 detectors from Teledyne e2v for three large focal planes covering the NUV, u’ and g’ bands, respectively. With the NUV band covering the 150-300nm wavelength range, the 2d-doping technology from NASA/JPL will be utilised to improve the quantum efficiency. The Open University will perform electro-optical testing and space qualification of the CIS303 and CIS120 detectors, including a comparison of different UV coating and enhancement technologies, and we present the most recent results of this work.
13093-149
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The Lunar Ultraviolet Observatory is designed to map the Earth exosphere, the magnetosphere and the near-Earth space. The observatory is a small space telescope to be set in Lunar orbit to produce wide field images (~20x20 deg2) in narrow and broad bands in the 115-175 nm spectral range. In this presentation, we will describe the results of the on-going tests of critical optical elements.
13093-150
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
Our group is working on developing Skipper CCDs with enhanced UV QE. In this paper we present the design and readout electronics for a 128-amplifier Skipper CCD. We calculate theoretical Skipper noise models and optimize readout times for a selection of scenarios. We provide the status of our on-going effort for extensive characterization of the noise performance of delta-doped enhanced Skipper CCDs, including our characterization setup and absolute quantum efficiency measurements. We propose a tentative project timeline, including planned lot runs, characterization tests, and on-sky testing.
13093-151
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
To broaden our characterization of light observed in our universe, we investigated the polarization performance in the Far Ultraviolet (FUV) range of 100-200 nm. Our plan to accomplish this is to build a polarizer for the FUV range and study its transmission efficiency in the lab. We have begun a trade study of different reflective element polarization designs specific for FUV/Vacuum UV wavelengths. This included using computer simulated polarizers and optics to observe alignment tolerance analysis, performing stray light signal analysis based on changing the angle of incidence, and determining how several different mirror coatings impact polarization performance as a function of wavelength.
13093-152
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
Recent developments in performing Physical Vapor Deposition in combination with fluorination by using a XeF2 gas have enabled the production of aluminum (Al) protected with a LiF overcoat with unprecedented reflectance performance in the FUV in addition to improved environmental stability. This coating technology involves a collaboration between the Goddard Space Flight Center and the Brigham Young University. This novel process has produced Al mirrors with FUV a state-of-the-art reflectivity of around 91% at 121.6 nm. In this paper, we report on environmental/material property characterization of these XeF2 fluorinated samples. This is done in order to advance the TRL for these Al+LiF mirror coatings.
13093-153
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
SUAVE (Solar Ultraviolet Advanced Variability Experiment) is a far UV imaging solar telescope (Lyman Alpha, 121.6 nm, Herzberg continuum, 200-242 nm, etc.) of novel design for ultimate thermal stability and long lasting performances over several years instead of, often, a few weeks or months in this wavelength range. SUAVE is a 80 mm Ritchey-Chrétien off-axis telescope with "mushroom type" SiC mirrors and no entrance window for long and uncompromising observations in the UV (no coatings of mirrors, flux limited to less than a solar constant on filters to avoid their degradation), associated with an ultimate thermal control (no central obscuration resulting in limited thermal gradients and easier heat evacuation, focus control, stabilization). Design and performances will be detailed as well as results of thermal/optical tests performed on the SiC primary mirror and its regulated support plate also in SiC. Plans for the realization of a representative telescope breadboard for testing both optical and thermal properties are presented. SUAVE is foreseen as the main instrument of the Solar/Climate microsatellite SoSWEET mission sized for New Space era platforms and launchers.
13093-154
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
Ultraviolet spectroscopy plays a vital role in studying exoplanets. Future UV spectrographs will require large-format, high-performance gratings (R > 10,000). Unfortunately, measuring the UV performance of a large-format grating from 900-2000Å is resource-intensive and requires large special vacuum facilities, hampering UV grating development. An efficient characterization process will save time and reduce costs, facilitating the development of blazed UV gratings for next-gen UV space telescopes.
This work is part of an effort to determine if we can leverage trends found between measured UV grating performance (on small stamp-size gratings) and the grating’s intrinsic, fabricated characteristics to estimate the expected performance of large-format UV gratings. Thus streamlining the process of grating characterization for future UV missions.
Here, we present a pilot study using an 855 nm period grating. We characterize the grating’s fabrication quality via interferometry and single-point metrology. Finally, we measure the grating's diffraction efficiencies and investigate any trends between its performance and its fabrication qualities.
13093-155
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
A NASA-funded technology maturation effort to develop multi-object spectroscopy in space will be performed with a digital micromirror device (DMD) on the Spectroscopic Ultraviolet Multi-object Observatory (SUMO) Prototype. It will be the first DMD-based instrument to operate in space as a secondary payload on the CU Boulder sounding rocket INFUSE. The SUMO Prototype consists of: a DMD manufactured by Texas Instruments, an off-the-shelf camera for the imaging channel, a custom NUV CCD camera developed in-house at the Laboratory for Atmospheric and Space Physics (LASP) for the spectral channel, a Raspberry Pi for the flight computer, a controller for the DMD, and an electrical power system (EPS) with a rechargeable battery. The SUMO Prototype is nominally scheduled for flight in the Spring of 2025.
13093-156
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The 2020 NASA decadal survey's highest priority is an IR/O/UV large telescope optimized for observing habitable exoplanets and for general astrophysics. This project, known as Habitable World Observatory (HWO), has strong UV scientific drivers requiring the need for high-efficiency, high-resolution diffraction gratings.
To meet those requirements, the ongoing development of UV-optimized gratings is key. To that end, we summarize our past and ongoing projects that relate to the fabrication of high-performance EUV (10-90 nm) and FUV (100-180 nm) gratings using electron-beam lithography and subsequent etching. This technology enables a high degree of customization with patterns that can have straight or curved grooves on a variety of substrates, allowing for aberration-correcting capabilities.
Building on those efforts, we will report our ongoing programs to fabricate the UV gratings for the MOBIUS and FORTIS suborbital sounding rocket missions, as well as for the MANTIS CubeSat.
This work not only serves as technology development for future large observatories like HWO, but also allows new science to be done onboard smaller missions.
13093-157
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
Understanding the coronal magnetism is important to answer long-standing questions in the solar physics, such as the problem of high coronal temperatures, the acceleration of solar energetic particles, and the dynamics behind the solar eruptions that drive the geospace weather. Our recent study has reported coronal emission lines in the extreme-ultraviolet (EUV) which are, in principle, sensitive to the weak magnetic field of the solar corona via the Hanle effect. However, measurements of the coronal magnetic field have remained sporadic till date, due to the challenges faced in designing and manufacturing high-reflectivity and high-polarizing optics for successful operation in the EUV spectral range. In this work, thin-film fabrication of highly reflective mirrors is performed in EUV spectral range between 740 to 800 Å using the beamline facility of the RRCAT, Indore. The properties of the fabricated mirrors are studied in terms of their long-term stability, throughput and polarizing power.
13093-158
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
We will outline the performance of delta-doped, photon-counting UV detectors (EMCCDs). We will present the recent quantum efficiency (QE) data from devices optimized for the FIREBall-2, an astrophysics balloon mission with a bandpass centered at 205 nm, as well as devices optimized heliophysics instrumentation for observing nitric oxide (NO) signals at 215. We will also discuss the newest detector developed for FIREBall-2 with an integrated solar-blind, UV bandpass filter; analysis will include an overall detector noise characterization.
Session PS3:
Posters - Athena Instruments
17 June 2024 • 17:30 - 19:00 Japan Standard Time
13093-159
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The differing operating temperatures of the DePFET sensor and the closely located Front-End Electronics require a thermal solution with two separate cooling chains for the Camera Head of the WFI instrument. The chosen solution minimizes the total area needed for Camera Head cooling. This paper explains the thermal design and cooling concept, which includes using highly conductive graphene thermal straps and considers the parasitic heat exchange between the two cooling chains due to the large number of bond wires and radiative heat exchange.
13093-160
The X-IFU Focal Plane Assembly Development Model: evaluation of the global magnetic shielding factor
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
This paper describes the evaluation of the global shielding factor of the Development Model (DM) of the X-ray Integral Field Unit Focal Plane Assembly (X-IFU FPA) for the Athena X-ray observatory. We use a number of TES detectors spread over the south quadrant of the array as very sensitive magnetometers. We discuss the difficulties in performing a measurement like this where a Helmholtz coil outside the cryostat were used to apply a small magnetic field (< 200 µH) in order to avoid any permanent magnetization of the cryo mu metal (CMM) shield. Both AC and DC external magnetic fields have been applied at different orientation respect to the detector plate. Preliminary results set a lower limit in the evaluation of the global FPA shielding factor of ~ 10^5. Improvement in the measurement setup and in the analysis will be discussed and eventually applied to the following model of the FPA.
13093-161
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
ESA’s Athena X-IFU will aim to provide high-energy (2.5 eV at energies up to 7 keV) and high-spatial (5") resolution spectroscopy over the energy range from 200 eV to 12 keV, by means of an array of transition-edge sensors (TES) readout via time-domain multiplexing (TDM).
SRON is responsible for the delivery of the focal plane assembly (FPA) for X-IFU, whose Demonstration Model (DM) will use for the first time a TDM-based readout. To study the operation of TDM towards the framework of X-IFU's FPA-DM, we received in late 2022 a cryogenic test-bed from NIST and NASA Goddard Space Flight, whose performance was limited to 2.8 eV with 16-pixel multiplexing (instead of 32), due to the length of the harness connecting the 4 K stage to the room temperature electronics.
In late 2023 we received new harness, designed to mitigate the limitation on the system performance. We report on the TDM system performance with the new flex harness, addressing issues related to their length such as electrical ringing and crosstalk. We discuss the envisaged methods to overcome them, the laboratory tests for their validation and an outlook on the future activities for its integration on X-IFU's FPA-DM.
13093-162
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
We present the electrical ground support equipment (EGSE) for the ESA NewAthena WFI. A WFI Structural and Thermal Model (STM), and Engineering Model (EM) prototype consisting of the Camera Head Sub-System (CHS) and Detector Electronics Sub-System (DES) is under development and completion is expected to mid-2024. The use of the WFI EGSE for the CHS and DES test campaign within the Max Planck Institute for extra-terrestrial physics test facilities is also described.
13093-163
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The Wide Field Imager (WFI) is one of the two focal plane instruments onboard ESA´s New-Athena space mission.It is a DEPFET-based X-ray detector operating in the energy range between 0.2 and 12 keV.During the former phase A/B1 a study of the camera configuration,largely based on Geant4 simulations,has been performed within the WFI background working group,in order to identify the shielding specifications and methods for the optimization of the trade-off between expected background and radiation damage.In this paper we summarize the findings as a result of the investigation focusing on ongoing activities at IAAT and discuss them in light of the SRG/eROSITA in-flight experience.
13093-164
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
This paper presents an overview of the design and development of VERITAS 2.3, an evolutionary step of the VERITAS (VErsatile Readout based on Integrated Trapezoidal Analog Shapers) readout integrated circuit (ROIC) architecture designed for high-speed, low noise readout of the DEPFET detectors in the Wide Field Imager on ESA’s Athena X-ray satellite. The chip includes 64 channels, delivering a short processing time of 2.5 µs per readout while targeting a system noise of 3 e- ENC RMS, enabling nearly Fano-limited spectroscopic performance. While the new chip still uses previous versions’ proven 0.35 µm CMOS technology node, we have employed new foundry and process options for better manufacturability and improved reliability. This paper discusses several design improvements like MIM caps instead of poly caps, fully differential drivers and better ADC connectivity.
13093-166
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
This paper will present the current status of the Detector Electronics (DES) development for the ESA NewAthena WFI. One STM for structural and thermal tests as well as two EMs to operate a Large Detector (LD) and a Fast Detector (FD) of the DES are under development. Each of the DESs consists of three modules: Galvanic Isolation Module (GIM), Power Conditioning Module (PCM) and Frame Processing Module (FPM).
13093-167
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
Athena is ESA’s X-ray observatory mission designed to address the Hot and Energetic Universe theme. The instrument consists of a single x-ray telescope, supported by a large area mirror focusing the photon flux alternatively onto two different instruments The process of switching the focus between the two instruments is produced by changing the pointing of the main X-ray mirror. The verification of the alignment of the mirror optical axis with respect to each of the instruments with accuracy better than 0.5 arcsec is achieved by means of an optical On-board Metrology System (OBM).
In this work we will present the experimental setup and processing architecture designed for calibration and testing the OBM demonstrator allowing to evaluate the performance of the on-board metrology system for the Athena X-ray Observatory mission.
13093-168
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
This work describes the magnetic modelling process of the X ray Integral Field Unit (X-IFU) multi-stage ADR last stage cooler and its effect on the Focal Plane Assembly (FPA) for the Athena X-ray observatory. Superposition of 2D axis-symmetric non-linear magnetic models are used to predict magnetic field levels outside the ADR cooler in absence of the FPA. Spatial variations of the relative permeability inside the ADR stage iron shields at different coil current levels is used to create a 3D linearized magnetic model. The FPA and its magnetic shields are added to this 3D model to make final predictions for the magnetic field inside the FPA produced by the multi-stage ADR at various points during the operation cycle.
13093-169
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The DRE (Digital Readout Electronics) of Athena X-IFU consists of three main parts: i) The Row Address and Synchronisation module synchronises the time domain multiplexed readout of the Focal Plane Assembly. ii) the Demultiplexer Module (DEMUX) linearises the cold front-end electronics and demultiplexes pixels data. iii) the Event Processor Module detects the events and measures the energy and arrival time of the X-ray photons. We have developed a demonstration model (DM) of the DEMUX module. It is representative of the flight model (size, components, design rules, mechanics, etc.). Its aim is to demonstrate the functionalities and performances of our electronics. The DEMUX DM is also a means of practicing operational procedures such as the so-called expertise procedures: These are test scenarios defined to characterise the instrument detection chains in order to identify the optimal operating points.
13093-170
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
This work describes the alignment verification test program performed on the X ray Integral Field Unit Focal Plane Assembly (X-IFU FPA) Development Model (DM). The alignment of the detector stage with respect to the external interfaces in warm conditions is verified by mechanical measurements on a 3D measurement machine. In addition relative movement of the detector stage compared to the outer structure is monitored in 5 Degrees Of Freedom (DoF) during several thermal cycles. The acquired data is compared to mechanical models using a rigid body transformation description. Finally, these results are used in the alignment strategy within the X-IFU FPA using the available alignment budget estimates.
13093-171
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
This paper gives a review of the ASIC design evolutions of the WFEE in the context of the ATHENA mission. The development follows the evolutions of the X-IFU instrument detection chain and secures the ASIC technology access continuity by using an ST SiGe 130 nm technology instead of the previous use of an AMS SiGe 350 nm node. First ASIC prototypes based on this ST 130 nm SiGe technology have been developed to answer these technical challenges and meet the new requirements. We will present these ASICs, the functions integrated into each integrated circuit and the improvements they have brought to the WFEE.
13093-172
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
This paper describes the thermal characterization of the Development Model (DM) of the X ray Integral Field Unit Focal Plane Assembly (X-IFU FPA) for the Athena X-ray observatory. We discuss the requirements on the thermal aspects of the FPA, and compare these with the results of a series of measurements made with the thermal model of the FPA DM (DM-TH): thermal stability, cryogenic heat loads, thermal capacity, conductance and time constants of the temperature stages in the FPA.
13093-173
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The Wide Field Imager (WFI) is one of two complementary focal plane cameras on ESA’s X-ray observatory Athena, whose launch is planned for 2036. This paper presents the preliminary design of the instrument based on its structural, thermal, and functional requirements, together with its numerical and experimental verification.
13093-174
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
In the context of the ATHENA X-ray space mission, the X-ray integral field unit (X-IFU) warm front-end electronic (WFEE) is a multichannel differential readout sub-system. As part of the verification of the performance several measurements are carried out, initially on the demonstrator model of X-IFU’s WFEE, and later for the production models. The transfer function from the 8 channels included in a demonstrator are measured, for excitation from a few 10s of Hz up to 50 MHz. Over the same frequency range, the inter-channel coupling and cross-talk are measured at a level below -80 dB. We also measure the power supply rejection ratio. For these purposes, a lock-in amplifier is used in differential mode, especially to extract the small cross-talk signals which are at the same frequency as the input excitation. We discuss the design of the demonstrator model mitigating cross-talk and the way we measure in differential the residual channels coupling.
13093-175
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
Space environment Ionizing particles could cause an increase of electronic flicker noise on a detection chain readout. We will present low frequency noise measurements of a readout subsystem and effect of total ionizing dose up to 100 krad obtained thanks to the irradiation of our electronics with 60Co source. We will discuss the impact on the noise readout of such radiation effects over the life-time of a space mission as ATHENA.
13093-176
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The ATHENA space mission will be the next generation X-ray observatory. The X-ray integral field unit (X-IFU) is ATHENA’s cryogenic spectro-imager observing the sky with thousands of superconducting micro-calorimeters. The detectors are based on transition edge sensors (TES) in time-division multiplexing (TDM). A Warm front-end electronic (WFEE) demonstrator model (DM) has been developed for the low noise biasing and readout of X-IFU’s cryogenic detection chain. After extensive testing, it has been delivered to the French space agency (CNES) for integration in the full detection chain DM. The WFEE DM is capable of reading out and biasing 8 TDM channels. Different configurations were chosen for some of the channels in order to find the best performance after testing of the full readout chain DM. Design and measured performances will be presented and discussed.
Session PS4:
Posters - Optics
17 June 2024 • 17:30 - 19:00 Japan Standard Time
13093-177
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
This paper presents an overview of the current state-of-the-art manufacturing process for Silicon Pore Optics mirror plates for NewATHENA. After more than 15 years of process development and with mission adoption expected in 2027, the focus starts to shift towards upscaling and optimizing the production process, to prepare for flight production. We will present recent progress and an outlook towards the future flight production scenario, touching on several areas of the manufacturing process, such as dicing, laser-ID labeling, automated measurement of plate parameters, and photolithography.
13093-178
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The ground calibration of the New-ATHENA mirror poses significant challenges owing to its unprecedented size, mass, and focal length. VERT-X is innovative calibration facility designed to tackle this exceptionally demanding task. It relies on an X-ray parallel beam, generated by a micro-focus source positioned at the focus of an X-ray collimator. A raster-scan mechanism enables the beam movement, covering all ATHENA optics at varying off-axis angles. The compactness of the concept offers several benefits, including the vertical geometry which implies minimal PSF degradation due to lateral gravity. Furthermore, this allows for a flexible choice of location. Indeed one of the most important feature of VERT-X is its contiguity with the mirror integration facility. The driving factor in the VERT-X design is to meet the ATHENA calibration requirement for Half-Energy Width (HEW) accuracy at 0.1”. Key contributors to the error budget in the VERT-X design include the source size, collimator error, and raster-scan pointing accuracy. This paper provides an overview of the current status of the development of these critical parts and of the first results of their performance test.
13093-179
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
Silicon Pore Optics (SPO) is the optic technology selected for the
production of the hundreds of mirror modules that will comprise the
European Space Agency's NewAthena X-ray mirror assembly. Each mirror
module starts from pristine silicon wafers that are taken through many
physical, mechanical and chemical steps to produce the about 160
individual mirror plates that are needed for its construction. At each
step in the production chain data are used to tune the details of each
process, and new data are collected to assess the quality of the
output. In this paper we describe how the different pieces of data
that become available during the production of the optics are brought
together in a system of data bases and software pipelines that is
meant to serve both the scientific and the production quality needs
associated with such a large effort. A few examples will be described
to illustrate the current status of these efforts and the work that
remains to be done before the production of the newAthena optics
begins in earnest.
13093-180
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
BEaTriX, the Beam Expander Testing X-ray facility, is operated by the INAF-Brera Astronomical Observatory in Merate (Italy) as ground support equipment for the verification phase in the context of NewAthena.
The facility is very compact but, thanks to an innovative optical design based on asymmetrical cut crystals associated with a paraboloidal mirror, can produce an expanded low divergence X-ray beam at the two monochromatic energies of 4.51 keV and 1.49 keV. The first beamline at 4.51 keV is already operational, as the commissioning was completed in Q12023. The second beamline at 1.49 keV energy has more challenging aspects from both design and implementation points of view: the monochromator stage is made with two Quartz crystals with asymmetric cut; the expansion phase is made by two ADP crystals also with asymmetric cut; the X-ray source needs to be very brilliant) due to the large fraction of photons rejected by the crystals. This paper describes the activities on going: the 4.51 keV X-ray beamline optimization and the tests performed on a coated MM will be presented, the implementation of the 1.49 keV components, and the comparison with other X-ray testing facilities.
13093-181
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
Development and qualification of X-ray reflective mirror coatings for the NewAthena mission is progressing with a focus on enabling the scientific capabilities of the telescope, given the new constraints of the redefined mission.
In this work, we consider both design and development of Ir/C multilayer coatings optimised to ensure the required performance across the spectral range, facilitating the mission science objectives. We present the demonstration of manufacturing capability for the optimised Ir/C multilayer coatings, and compatibility with the SPO technology. Characterisation of X-ray mirror coatings is performed using X-ray reflectometry with a focus on mirror design qualification and long-term stability assessment.
13093-182
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
NewATHENA’s mirror assembly uses Silicon Pore Optics technology. It is important to assess and confirm the latest mirror design’s ability to meet the mission’s science goals.
This study performs ray-tracing simulations of NewATHENA’s updated SPO mirror assembly using the ray-tracing tool SPORT. The optics are illuminated by distant point sources at a range of energies and incidence angles corresponding to the mission’s science goals. The simulated mirror surfaces use the reflective properties of the most up-to-date thin film coating recipes for the mission.
The results of the simulations are presented as figures for the effective area and angular resolution of the optics at each simulated energy and angle.
13093-183
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
We present a concept of hard X-ray telescope that could realistically reach angular resolution of arc- second level. The optics is based on Kirkpatrick-Baez (KB) configuration realized with Silicon Pore Optics (SPO) technology. SPO has been developed for 15 years at cosine (The Netherlands) for the European Space Agency's next generation large X-ray telescope, NewAthena. It provides all the elements to realise a high-angular-resolution KB optics.
In this configuration the plates only need a slight meridional curvature and are flat in the sagittal direction, which reduces drastically the stress they undergo, and consequently the formation of slope errors. SPO is well suited for KB configuration as the ribs running along the plates block efficiently stray light. Without sagittal curvature, the KB mirror modules can be designed for the very small grazing incidence required for reflectivity at high energies. This type of telescope could be well suited for solar physics or astrophysics as a complement to NewAthena.
13093-184
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
Several hundreds of Silicon Pore Optics (SPO) mirror modules will be integrated and co-aligned onto the NewAthena Mirror Assembly Module (MAM). The integration process has been developed by Media Lario and exploits a full-size optical bench to capture the focal plane image of each mirror module when illuminated by an UV plane wavefront at 218 nm. Supported by ESA, Media Lario designed the Assembly Integration and Test (AIT) facility, able to illuminate the complete ATHENA Mirror Assembly Module (MAM). The building housing the AIT facility is under advanced construction at the Media Lario premises (near Milan, Italy), it extends 6.5 m below ground and 17 m above ground. The building is dimensioned to accommodate, beside the AIT facility, the vertical X-ray (Vert-X) test facility. The co-location of these two facilities is strategic for the project and will permit regular checks of the Mirror Assembly Module while is populated and its final calibration. The facility is designed with a rail system connecting the two facilities, allowing the transfer of the Mirror Assembly Module between the two. This paper reports on the status of the commissioning of the AIT facility.
13093-185
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The ALBA Synchrotron (Barcelona, Spain) has built MINERVA a new X-ray beamline designed to support the development of the NewATHENA mission (Advanced Telescope for High Energy Astrophysics), which objective is to observe and study energetic objects in space (accretion disk around black holes, large-scale structure, etc...). MINERVA is dedicated to assemble stacks manufactured by cosine into mirror modules (MM), building blocks of the NewATHENA optics. The new beamline is originally based on the monochromatic pencil beam XPBF 2.0 at the Physikalisch-Technische Bundesanstalt (PTB at BESSY II) but also includes new designd and additional features on the scanning scheme to improve the characterization time of each MM produced. Interoperability between MINERVA and XPBF 2.0 is nonetheless preserved to boost the mass production of the MMs and characterize their performance. MINERVA is now in operation and has been co-funded by the European Space Agency (ESA) and the Spanish Ministry of Science and Innovation.
13093-186
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Robotic polishing currently falls short of ultra-precision requirements, which involves nanometric precision polishing. To address this, a simulation method has been developed to assess the effect of equipment vibration on polishing outcome, from which the level of force adjustment needed to ensure consistent fine polishing is determined. A passive compliance control is demonstrated that can successfully maintain precise surface slopes, by imposing a nearly constant contact force.
13093-187
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Silicon Pore Optics (SPO) was developed for light-weight X-ray telescopes with a large collecting area. Using technology from the semiconductor industry, thin mirror plates are produced from silicon wafers, and combined into modules. It offers a large degree of customization. We discuss how SPO can be optimized for a mission by altering the properties of the plates and the configuration of the modules. We show how the configurability of SPO makes it an attractive X-ray optics technology for a wide range of applications.
13093-188
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The INSIST (Indian Spectroscopic and Imaging Space Telescope) is a UV- optical 1m class space telescope expected to produce high quality imaging and moderate resolution spectra of astronomical sources. A Digital Micro-mirror Device (DMD) will be used in front of the on-board multi object spectrograph for sampling light coming from astronomical sources of interest in the light path. The role of DMD here is similar to slit mask used in the conventional spectrographs. DMD comprises of tiny mirror-lets arranged in the form of pixels which can be flipped between two pre-defined positions by applying digital signals. By selecting the appropriate pixels on the DMD the required slit mask shape can be configured. The DMD controller will transfer the slit mask pattern to the DMD device. Controller will be interfacing with imaging electronics to get the information about required mirror lets to be flipped to form a slit mask pattern. Controller will also be sending telemetry data to on-board computer for its health. This controller can also be used for ground based astronomy also with small interface modifications.
13093-189
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The PANTER X-ray Test facility is a 130m long vacuum tube utilized to produce forefront characterization of next generation X-ray optics. We present results from a PANTER campaign to characterize high-resolution X-ray technology including mono-crystalline silicon optics which have planned use on several proposed NASA X-ray Explorer and Probe missions, as well as off-plane reflection gratings which serve as an option to achieve the spectral resolution requirements of a Lynx-like flagship mission. Additionally, the second flight module of the Joint European Telescope for X-ray astronomy (JET-X FM2) was re-tested to follow up on a prior characterization study of the instrument at the same facility. This campaign demonstrates near-equivalent performance measurements of the JET-X optic after a decade of storage, while also demonstrating the ability of mono-crystalline silicon mirrors and aberration correcting, blazed reflection gratings. Results confirm the high-resolution performance of polished silicon optics as well as the high-resolution, high-efficiency performance of the diffraction gratings.
13093-190
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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In the development of next generation telescopes, the quality of optical surfaces in terms of micro-roughness is an important parameter for determining their performance and it is constantly monitored during the manufacturing process. While portable instruments are commonly employed for on-surface monitoring, their feasibility diminishes with large or immobile optics in case of complex geometry. In such scenarios, the replica approach emerges as a highly efficient alternative, involving the acquisition of imprints on surfaces with specialized pastes. This paper aims to systematically characterize the measurement process by comparing standard methods with the replica approach. Samples of diverse materials and surface qualities will be measured at various manufacturing stages. The goal is to optimize the process, providing a comprehensive insight into its advantages and effectiveness.
13093-191
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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We report our development activities of precision Wolter mirrors for future soft X-ray imaging observations of the Sun.
By direct polishing of a glass-ceramic substrate, an engineering Wolter mirror of 3-m focal length was fabricated whose mirror area was 40 mm x 50 mm for each of the parabola and hyperbola sections. X-ray imaging performance of the mirror was then evaluated with 8-keV parallel X-rays at SPring-8/BL29XUL. For the mirror area whose tilt up to >6 degrees along the cylindrical direction, the mirror showed imaging performance of ~0.25 arcsec FWHM (~0.55 arcsec HPD) with the scattering level ~1 x 10^(-4) of the PSF peak at 30-arcsec off-axis position.
Status of the development including the above result will be reported and future prospects will be discussed.
13093-192
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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We have developed one-dimensional X-ray optics for the kind of scan-type detector like the Gas Slit Camera (GSC) onboard MAXI. GSC consists of gas proportional counters with slat collimators and has the sensitivity of order of 10 mCrab by an orbit (92 min) scan. Aiming to detect more fainter sources such as afterglows of gamma ray bursts and electromagnetic counterparts of gravitational wave events than the sensitivity, we investigate a scan camera with one-dimensional X-ray optics. By mounting one-dimensional X-ray optics in place of slat collimators on slit and sensor, the sensor receives more focused photons with small size without decreasing total field of view during an orbital period.
We have developed X-ray tracing simulations of the optics by Geant4 including X-ray total reflection process with a goal of detection sensitivity to 1 mCrab/orbit.We fabricated the test model of flat mirror optics of conical approximation of Wolter-I which was designed based on the simulation, and the performed the measurement of X-ray image of the model at ISAS 30 m X-ray beam-line.
We will report on the design of X-ray optics, the simulation by Geant4, and the results X-ray experiment.
13093-193
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Swift Solar Activity X-ray Image (SSAXI), mounted on the High Resolution Coronal Imager (Hi-C) as a sub payload, is a wide field solar X-ray imager designed to image Solar X-ray flares at high cadence (>5 Hz). SSAXI consists of a Wolter-I optic with a focal length of 1 m, coupled with a monolithic CMOS X-ray sensor at the focal plane. The flight optic selected for SSAXI shows on-axis 16” Half-Power Diameter (HPD) and 5” Full Width Half Maximum (FWHM) at 4.5 keV, exceeding the 23” HPD and 9” FWHM requirement. The effective area is about 0.7 cm2 at 4.5 keV. Here we review the design, fabrication and testing of the SSAXI optic and summarize its performance.
13093-194
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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NewAthena (New Advanced Telescope for High-Energy Astrophysics) has been endorsed by the European Space Agency in November 2023 and the mission is entering a pre-industrialization phase prior to the foreseen adoption early 2027.
A key aspect of the thin film coating development for the NewAthena X-ray optics, is to determine the adhesion efficiency and the residual stress limitation of the coatings on silicon substrates. To do so, we magnetron sputtered different layer thicknesses of chromium layers underneath iridium/carbon bilayer and linear graded multilayer coatings.
The samples were characterized using X-ray Reflectometry (XRR) to derive the thickness, micro-roughness and densities. The residual stress was assessed by profilometry using a Dektak 150 stylus profiler device from Bruker. The curvature of the samples prior and post coating, along with the total film thickness derived from XRR, were used to evaluate the residual stress. The adhesion was investigated using tape tests.
13093-195
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Future x-ray telescopes require reflective coatings on extremely thin mirror shells to achieve both high optical throughput and good angular resolution. Traditional coating methods such as DC magnetron sputtering create coatings with high density and low roughness, which have delivered quality coatings for NuSTAR and Chandra. However, these sputtered coatings have intrinsic compressive stress, which distorts the figure of the thin mirror shells, degrading angular resolution or necessitating complex correction process on fabrication. In this paper, we investigate Atomic Layer Deposition (ALD) for coating x-ray telescope mirrors. ALD has many potential advantages, including 1) Simultaneous, net distortion-free coating of both sides of thin mirrors, and 2) Uniform thickness control across multiple mirrors, essential for mass production. We study these capabilities through the ALD coating of both curved silicon mirrors and flat silicon wafers with 30 nm iridium layers. We investigate ALD coating using optical metrology to measure its figure distortion, x-ray reflectometer (XRR) to measure its surface roughness and density, and monitor its long-term stability.
13093-196
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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In recent years, we have introduced and evaluated an innovative class of organic coatings designed to enhance the soft X-ray reflectivity of grazing-incidence optics. These coatings can be effortlessly applied to pre-existing optics using a straightforward dip-liquid process. Our research has explored the potential utilization of these coatings in advanced space missions, such as ATHENA and eXTP, and we have rigorously examined their performance on realistic optic models.
In this study, we present the outcomes of a refined coating process and provide insights into initial environmental tests. These tests are pivotal in establishing the feasibility of employing these coatings in upcoming space missions.
13093-197
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Lobster eye optics are expected as a wide-field telescope and are suitable for future X-ray sky surveys and monitoring missions. We have developed ultra-lightweight X-ray optics with MEMS technologies and applied the same way to the fabrication of lobster eye optics. A large number of slits with 20 micro-meters width were formed by an etching process in a 4-inch Si wafer with 300 micro-meters thickness. To collect X-rays on a focal plane, the wafer was plastic-deformed into a spherical shape with a curvature radius of 1000 mm. Two deformed wafers were assembled in such a way as to orthogonally arrange the slits of each wafer. Then, we completed samples of lobster eye optics with MEMS technologies.
13093-198
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Designing and building X-ray telescopes that observe the high-energy universe with large-effective area and sub-arcsecond angular resolution has proven to be a great optomechanical challenge, as thin, tightly-nested grazing-incidence mirrors are easily deformed during assembly. We are developing a bonding and alignment process in which we fabricate spacers, bond them between thin mirrors, and re-align these mirrors after assembly, using a Hartmann test for alignment metrology. We implemented a non-contact slumping method to produce smooth Eagle XG conical mirrors. Using an ultrafast laser, we weld fused silica spacers to these mirrors to create mirror segment stacks. We will present measurements of how this assembly process affects the figure of our thin mirrors, and report on progress on finite-element modeling of our mirror stack assemblies such that mirror alignment can be precisely predicted and implemented with ultrafast laser-generated strain. We will also report on progress toward building Hartmann metrology capabilities at the University of Arizona. The presented assembly process serves as a promising approach towards building next-generation X-ray telescope mirrors.
13093-199
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Ultrafast laser stress figuring (ULSF) is a figuring process that can deform optical substrates using ultrafast laser generated stress. This technique would be a valuable tool in the mirror substrate manufacturing process if it can be predictably applied to a wide range of substrate geometries and surface height errors. This work explores the simulation of the capabilities of ULSF using Monte Carlo analysis with nonlinear optimization of corrected RMS surface height error.
13093-200
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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This work investigates the importance of substrate quality and contamination of thin film coatings, essential for high-energy mirrors used in astronomical missions and other applications, focusing on the manufacturing process from substrate production to final assembly of the optics. Characterization of thin film coatings is crucial for evaluating the performance of X-ray telescopes. A multifaceted and synergized methodology utilizing X-ray reflectivity (XRR), X-ray photoelectron spectroscopy (XPS) and optical microscopy (OM) is presented. Herein, we discuss coating performance, encompassing substrate preparation, coating deposition, and storage conditions.
13093-201
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The assembly of X-ray mirror modules for missions such as STAR-X, AXIS, HEX-P and LEM that exhibit both high resolution and a low mass to effective area ratio poses many unique challenges. Sub-arc-second silicon X-ray mirrors must be assembled without degrading either the image quality or alignment at a very high level of precision, while also providing the strength and stability to withstand launch and on-orbit environments. This paper will address the structural analysis methods and testing that has been conducted to verify the silicon mirror modules being constructed at Goddard Space Flight Center. This analysis includes structural integrity and distortion effects on individual mirror segments, as well as structural design considerations for module interface structures that allow individual modules to be finely aligned into a full mirror assembly.
13093-202
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Reflection gratings are critical components to successful X-ray spectroscopes and represent important priorities for future NASA observatories. As such, significant research efforts have been invested to improve mirror and grating fabrication, resulting in increased collecting area and improved mirror performance. However, residual stresses induced by reflective coatings continue to present challenges, causing mirror deformation, degradation of spectral resolution, and decreased scientific performance. Though macro stresses on thicker layers are more easily calculated, localized stress distributions and the stress response of nanoscale layers (5-30nm) are not well understood and can be difficult to measure. This study demonstrates synchrotron XRD methods using the sin^2ψ technique to better characterize and minimize the stress of single and bi-layered nanoscale reflective layers (5-30 nm) for applications in X-ray optics. Residual stresses are spatially mapped across an optic and analyzed at different deposition conditions and anneal treatments. High-Z materials (Ir, Pt, Au) have been chosen for this study due to their favorable reflectivity over the soft X-ray regime.
13093-203
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Filter stacks in microcalorimeters (such as those being designed for the Athena X-IFU) must protect the detector from photon shot noise and thermal radiation, while being transparent to X-rays, being able to survive the mechanical loads from launch vibrations, survive a differential pressure during pumping, and be able to be maintained at a constant temperature with a small power draw. This research looks at the benefits of using SiC for the grid material compared to the steel/Au or silicon grids that are more traditionally used. Due to its material properties, SiC offers lower membrane stress and improved thermal conductance than the steel/Au counterpart allowing for smaller power draw to maintain filter temperature for contamination control. SiC also offers an increase in strength compared to Si grids with the SiC grids having been shown to be ~5 times stronger over small apertures (10 mm). SiC grids have been developed, burst tested with a differential pressure, and vibration tested with vibration loads up to the NASA GEVS standard of 14.1 g rms. Optical inspection of the grids before and after vibration is used to show if the meshes can withstand standard launch vibration loads
13093-204
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Orbital soft protons that reach the detector region of astronomical X-ray observatories can seriously degrade the instrumental performance. Firstly, they pose a non-reducible background component and, secondly, they might induce permanent sensor damage. A reliable performance estimation and risk assessment for new X-ray missions is only possible with experimental scattering data.
Therefore, we conducted measurement campaigns at various accelerator facilities and at different energies below 1 MeV in the past decade. Targets ranged from classic gold-coated nickel shells to the silicon pore optics (SPO) design foreseen for Athena.
The latest measurements were taken with a new setup at considerably lower energies from 20 keV to 50 keV, and with an MCP detector that features two dimensional position resolution. The results are highly relevant for background studies and have a finer angular coverage. Furthermore, the data yield hints that a significant fraction of scattered protons undergoes charge exchange and, thus, is not affected by a magnetic diverter.
In this contribution, we present the new experimental setup and give an overview on the proton scattering results obtained so far.
13093-205
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Future soft x-ray spectrometers that use reflection grating technology typically call for arrays of custom gratings to be integrated into a Wolter-type telescope, where they intercept and disperse radiation coming to a focus over several meters. To enable both high spectral sensitivity and high spectral resolving power simultaneously, each grating requires blazed groove facets patterned over an aberration-correcting layout, such as a fanned, or “radial”, profile that matches the telescope focal length. A large-format master grating that meets such specifications with blazed, radial grooves has been fabricated at the Penn State Materials Research Institute and tested for spectral resolving power at the PANTER X-ray Test Facility of the Max Planck Institute. This presentation describes how the grating was fabricated using the electron-beam process of thermally-activated selective topography equilibration (TASTE), which has the key advantage of producing blazed groove facets in polymeric resist over a non-parallel groove layout not limited by substrate crystal structure.
13093-206
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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We report on progress evaluating errors common in the fabrication of blazed reflection gratings for use in ultraviolet astronomy. Gratings studied are produced via electron beam lithography (EBL), nanoimprint lithography (NIL), and potassium hydroxide (KOH) wet-etching and are measured interferometrically. Fabrication errors which manifest as groove discontinuities are of particular interest as they cause “Rowland Ghosts,” or the appearance of a multiplicity of a single diffracted order due to error in the grating’s periodicity. This means that, though a grating may have high spectral resolution or high total efficiency, there is a blending of light from primary and ghost orders leading to an overall loss of information. Understanding the effect of these feature placement errors is critical to the characterization of how these gratings would behave when integrated into a spectrograph. We report on progress simulating the intensity distribution and Rowland Ghosts generated by real, imperfect, gratings fabricated via EBL, NIL, and KOH and measured interferometrically in an effort to understand each technique’s limitations and characterize their performance.
13093-207
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The next generation of reflection gratings for future high-energy space observatories needs a high degree of customization. Making such gratings will require the use of increasingly complex nanofabrication techniques. One of the current challenges we are investigating is the precise patterning of grooves onto curved substrates, which is needed for effective aberration correction. We report on our use of electron-beam lithography to pattern large format gratings on cylindrical substrates. We will discuss the fabrication steps involved, from the alignment of the substrate to the actual writing strategy. Ongoing optimizations and future steps will be discussed, including the additional challenges involved in patterning a segmented X-ray mirror.
13093-208
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Precisely shaped thin X-ray mirrors that enable high effective area and high angular resolution are required for the mirror assemblies in the next generation of X-ray telescopes. To address this need, the deterministic figure correction capabilities of an adjustable X-ray mirror are reported. This ~ 0.4 mm thick optic segment measures 10.16 cm axially by 10.16 cm azimuthally and employs 288 lead zirconate titanate thin-film actuators. When each actuator is individually addressed with a low DC voltage, it induces a localized figure change to the mirror. The method of using measured actuator responses to simulate correcting low spatial frequency (< 1 mm^(-1)) figure errors is described. The process for filtering high spatial frequency metrology errors from measurements and the figure correction algorithm used is outlined. These corrections are compared with those simulated using a set of finite-element analysis modeled actuator responses.
Session PS5:
Posters - Detectors and Operations
19 June 2024 • 17:30 - 19:00 Japan Standard Time
13093-209
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
Axions are one of the leading candidates for the hypothetical, non-baryonic dark matter expected to account for about 27% of the energy density of the Universe. Axion helioscopes are axion experiment searching for axions produced in the core of the Sun via the Primakoff effect by utilizing strong magnetic fields, x-ray optics and ultralow-background detectors. The International Axion Observatory (IAXO) is a next generation axion helioscope aiming at a sensitivity to the axion-photon coupling of 1-1.5 orders of magnitude beyond the current most sensitive axion helioscope, the CERN Axion Solar Telescope (CAST). BabyIAXO (BIAXO) is an intermediate scale helioscope with sensitivities to axion-photon couplings down to a few 10^-11 GeV-1 reducing risks for IAXO while delivering first significant physics results. The optics for (B)IAXO are multilayer-coated Wolter-I approximations. Two pathfinder optics have been successfully tested in CAST and at the Panter x-ray test facility of MPE. Here we introduce (B)IAXO and detail the optics and coating design along with the pathfinder performances.
13093-210
The next generation of solar axion searches: the International Axion Observatory (IAXO) and BabyIAXO
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Axions appear in well-motivated extensions of the Standard Model (SM) including the Peccei-Quinn mechanism proposed to solve a long-standing problem in QCD (strong-CP problem). More generic axion-like particles (ALPs) appear in other extensions of the SM, most notably string theory. Axions and ALPs are invoked in a number of cosmological and astrophysical scenarios. Most relevantly, these particles are well-suited candidates to compose all or part of the cold dark matter.
Here we present the next generation of axion helioscope searches - the International Axion Observatory (IAXO) and its intermediate experimental stage BabyIAXO proposed to be sited at DESY. IAXO is a large-scale axion helioscope that will look for axions and ALPs from the Sun with unprecedented sensitivity. BabyIAXO is envisioned to test all IAXO subsystems (IAXO prototype), while probing relevant physics with significant potential for discovery of the (still hypothetical) dark matter candidates.
13093-211
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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To investigate the density of the upper atmosphere at ~100 km by X-ray observations of the cosmic X-ray background (CXB) through the Earth rim, we are developing a specialized instrument for this purpose. It consists of a slit collimator and SOI-CMOS sensors and is planned to be installed on the International Space Station (ISS) in 2025. In this talk, we study the feasibility of the observations by considering the attitude fluctuation of the ISS and the particle background in orbit and estimate that the observation efficiency of the CXB is about 70%.
13093-212
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The development of an interface to analyse and characterise the performance of Michrochannel Plate detectors (MCP) is presented. This tool can process the images generated when photons reach the detector, from the splitting of the video recorded into frames to the generation of a list where events are extracted and classified providing their position, size or intensity.
The interface has been created using Python programming language and the DAOFIND algorithm for the identification of events, and it will be opened to the scientific community.
13093-213
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Accurate characterization and control of stray light are crucial in ensuring the precision and reliability of the test facilities. This paper focuses on the comprehensive stray light analysis conducted on the optical chamber at the PANTER test facility. Employing simulation tools and observation results, the study investigates the potential sources and pathways of stray light within the optical chamber, which possibly interferes with the performance verification of the X-ray optics. Results from the study provide valuable insights into the stray light environment within the PANTER optical chamber, aiding in the optimization of testing conditions and contributing to the broader understanding of maintaining precision in optical measurements. This work is essential for enhancing the overall performance and reliability of future measurement and calibration campaigns.
13093-214
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present a principle of a novel pointing direction metrology system that enables high-resolution X-ray imaging.
The concept of this system is to identify pointing direction by mapping the X-ray detector coordinate onto the celestial coordinate directly, utilizing the optical conjugate between the celestial sphere and the X-ray detector plane.
In this system, visible light sources are placed around an X-ray detector.
The light from the sources is projected through an X-ray mirror onto the field of view on the celestial sphere.
By measuring the projected position precisely, pointing direction can be determined.
It should be noted that our method can eliminate the uncertainties from the X-ray mirror and the supporting structures in principle.
Actually, the concept is realized by using a star tracker to image the light from stars and the projected light onto the celestial sphere through the X-ray mirror, at the same time.
Show Abstract +
Since 2019 SRG/eROSITA is the first X-ray instrument in orbit around the second Lagrangian point L2.We present an updated study of its particle background based on cleaned data and improved simulations.We also report a comparison between real and simulated data for the case of MIP rejection switched off.
13093-216
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Space Industry Responsive Intelligent Thermal (SpIRIT) 6U CubeSat, launched in late 2023 is an Australian-Italian mission for high-energy astrophysics that carries in a Sun-synchronous orbit an actively cooled HERMES detector system payload.
We will provide an overview of the SpIRIT early orbital operations, with the commissioning and in-flight calibrations of the instrument.
13093-217
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Future X-ray astrophysics missions will survey large areas of the sky with unparalleled sensitivity, enabled by lightweight, high-resolution optics. These optics inherently produce curved focal surfaces with radii as small as 2 m, requiring a large-area detector system that closely conforms to the curved focal surface. We have embarked on a project using a curved CCD detector technology developed at MIT Lincoln Laboratory to provide large-format, curved detectors for such missions, improving performance and simplifying design. We present the current status of this work, which aims to curve back-illuminated, large-format (5 cm x 4 cm) CCDs to 2.5-m radius and confirm X-ray performance. We detail the design of fixtures and the curving process, including models showing that the process will not exceed the fracture stress or have significant effects on electrical properties. We present results on curving monitor devices and characterizing the surface geometric accuracy. We finally show X-ray performance measurements of planar CCDs that will serve as a baseline to evaluate the curved detectors, in particular the spectroscopic performance in the soft X-ray band.
13093-218
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We report on the development status of the CMOS camera to be installed in GEO-X. We have evaluated the spectral performance of the sensor by irradiating it with polychromatic X-rays. The energy resolution is found to be 120 eV (FWHM) at 0.6 keV and the lower edge of the effective energy range is below 300 eV. The fabrication of the printed circuit boards for housekeeping data collection is ongoing. We performed functional testing of a digital processing board using SoC (Zynq) and its radiation tolerance investigation. We also report the latest schedule for the FM camera and end-to-end test.
13093-219
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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NuSTAR has achieved a milestone by deploying the first orbiting telescopes that concentrate light on high-energy X-rays. Future missions may leverage advancements in hard X-ray mirrors for more precise measurements. We present the first prototype of the HEXID ASIC: a novel pixelated front-end tailored for processing finely segmented CZT sensors. This readout ASIC efficiently handles photon-generated charge across a broad dynamic range (up to 180 keV), maintaining low input noise featuring a compact pixel size of 150um. The developed ASIC architecture will be reviewed, and the initial characterization of the physical prototype will be presented.
13093-220
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Microchannel plate (MCP) detectors have been the workhorse detector for many applications, including space borne ultra-violet imaging and spectrographic instruments. Recent advancements in additive manufacturing (AM) have enabled fabrication of complex structures with nano-scale resolution facilitating the production of highly customizable MCPs. Using AM to produce MCPs potentially has many advantages over traditional fused glass substrates, including better material control (e.g., more robust glasses or ceramics), better control of microscopic features (e.g., unique pore geometries to improve performance), and better control of macroscopic features (e.g., printing precision curved surfaces for focal plane matching). Through a collaboration with industry, national laboratory, and university partners, small format microcapillary array substrates were produced using a standard polymer photoresins. These substrates were functionalized using atomic layer deposition and their performance was compared to current state-of-the-art Pb-glass and borosilicate-glass MCPs.
13093-221
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The High Resolution Energetic X-Ray Imager (HREXI) is a scalable detector plane architecture that utilizes the NuSTAR ASIC (NuASIC) at the front end to readout large arrays of 2 cm × 2 cm, 3 mm thick pixelated CdZnTe (CZT) detectors; each with a monolithic cathode deposited to the upper surface and a 32 × 32 array of 550 μm pads distributed across the lower anode surface with a 604.8 μm pitch. The CZT anode pads are bonded directly to the inputs of the NuASIC
located on the upper surface of the silicon die with an identical pattern.
The architecture of the detector plane is hierarchical and consists of 3 primary layers: (1) the detector crystal array (DCA) board, which support the operation of a 2 × 2 array of NuASIC-coupled CZT detectors; (2) the FPGA mezzanine board (FMB) that supports the operation of a single FPGA capable of supporting the operation and readout of a 2 × 2 array of DCAs; and (3) the detector module board (DMB) which accepts data streams and controls up to 8 chains of 8 FMBs, a total of 1024 individual detectors with an active area of approximately 4096 sq. cm.
Here we present the qualification, performance and applications of this system for astronomy.
13093-222
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Thin-film optical devices have been on board X-ray satellites. We have proposed to utilize graphene in X-ray astronomy. Graphene is atomically-thin but possesses superior heat resistance and mechanical strength. Thus, we have been developing ultra-thin film optical devices capable of achieving ultra-high transmittance in the extreme ultraviolet to soft X-ray bands. Transfer processes have been optimized to realize large aperture structure and we successfully fabricated freestanding structures of 300 µm in diameter with a single layer and 800 µm with a bilayer of graphene. Moreover, we conducted high-speed atomic oxygen irradiation tests. The results showed no significant change in the observed D/G ratio in the Raman spectra at fluences up to 2×10^17 atoms/cm^2. However, at a fluence of 2×10^18 atoms/cm^2, the D/G ratio exhibited a significant change from 0.04 ± 0.03 to 0.8 ± 0.4. In this presentation, we will report our recent status.
13093-223
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
In addition to studying galaxies and the early Universe, future deep synoptic surveys will be essential to our understanding of the structure and history of the Milky Way (MW) by providing unprecedented data on the faint galactic stellar populations. However, observing stars at unrivalled depths presents challenges in identification and calibration.
Using the unprecedented 27.1-mag median depth of the Canada-France-Hawai‘i Telescope Large Area U-band Deep Survey (CLAUDS), we precisely studied the galactic stellar populations among over 15 billion of astronomical objects, over 20 square degrees.
In the absence of parallax measurements in the CLAUDS data, we devised photometric methods relying solely on colours to select stars in a survey designed to observe galaxies. We demonstrated the usefulness of precise measurements in determining properties of foreground stars, particularly white dwarfs (WDs).
Furthermore, through the analysis of WDs in the CLAUDS data, we developed a powerful technique for reducing systematics in synoptic surveys, such as the Legacy Survey of Space and Time (LSST). This technique could significantly enhance data quality in future deep synoptic surveys.
Session PS6:
Posters - XRISM
19 June 2024 • 17:30 - 19:00 Japan Standard Time
13093-224
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We report the first evaluation of the pointing accuracy of XRISM. It carries two X-ray telescopes, three star trackers (STTs), and two inertial reference units (IRUs). The attitude of the satellite is updated when at least two STTs are activated. Otherwise, IRUs keep it. The pointing accuracy is affected by the relative position of these devices, thermal conditions, and aberration. Therefore, it depends on several conditions such as the STT selection, the direction of the Sun, and the orbital movement. The fluctuation of attitude results in a change of the focal positions on the detector planes and the blur of the reconstructed image. We evaluated the trend from observations with different sun directions and STT combinations. The focal position on the microcalorimeter array was also validated.
13093-225
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Resolve soft x-ray spectrometer was designed to operate on the X-Ray Imaging and Spectroscopy Mission (XRISM) satellite. In the beam of Resolve there is, between the mirror and the detector, a filter wheel containing three x-ray filters and one position with a Fe55 calibration source. Also in the beam is an electronically controlled calibration source (the Modulated X-ray Source or MXS) which can provide pulsed x-rays to the detector to facilitate gain calibration. This article discusses the properties and performance of the filters and MXS during ground and early in-orbit operations of the Resolve instrument.
13093-226
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Soft X-ray Imager (SXI) is an X-ray CCD camera of Xtend onboard the XRISM satellite which was successfully launched on September 7, 2023 (JST). At ground cooling tests of CCDs in 2021, we experienced an unexpected issue in which anomalous charges occurred outside the imaging area of the CCDs, and intruded into the imaging area seriously affecting the imaging and spectroscopic performance. Through experiments with non-FM components, we identified a charge intrusion path and developed a new CCD driving technique to prevent charge intrusion and keep spectroscopic performance that satisfies the requirements, even if this issue occurs in orbit. In this paper, we report an overview of the anomalous charge issue, the development of the new CCD driving technique, the performance by it obtained in the SXI and satellite thermal vacuum tests, and the results of cause investigation experiments.
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In X-ray astronomy, multi-pixel photon-counting devices are utilized to observe X-ray radiation from astronomical objects. When the photon-counting devices observe bright sources, they generally suffer from pile-up, which leads to mistakes in the observational properties of the source: hardening in the X-ray spectrum and apparent decrease in flux. X-Ray Imaging and Spectroscopy Mission (XRISM) equipes an X-ray telescopes “Xtend”, whose focal plane detector is a CCD camera with a wide field-of-view of 38 arcmin square. We develop the pile-up simulator for Xtend to provide a quantitative assessment of pile-up according to the fluxes of objects. The simulator is based on Monte-Carlo simulation utilizing GEANT4. In this paper, we report a development of the pile-up simulator, its application, and the anticipated effects of pile-up for Xtend.
13093-228
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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XRISM (X-Ray Imaging and Spectroscopy Mission) is an astronomical satellite launched successfully on September 7th, 2023 (JST). One of the mission instruments, SXI (Soft X-ray Imager) consists of CCDs, analog and digital electronics, and a mechanical cooler and cooler driver. During the initial operation phase, we verified our operation procedure, stability of the cooling system, performance of all the observation options with different imaging areas and/or timing resolutions, and operations for protection against South Atlantic Anomaly and day-earth occultation. We optimized the operation procedure and observation parameters including the cooler power, imaging areas for specific modes with high timing resolutions, and X-ray-event selection algorithm. In this presentation, we summarize our policy and procedure of the initial operations of the SXI. We also report on a couple of unexpected issues we faced during the initial operations and how we dealt with them.
13093-229
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Resolve instrument on XRISM performs high-resolution spectroscopy in the soft x-ray band using a 6x6 microcalorimeter array cooled to 50 millikelvin by a 3-stage ADR. The use of 3 stages enables the ADR to use a tank of superfluid helium at 1.2 K or a Joule-Thomson (JT) cryocooler operating at <4.5 K as its heat sink. Resolve launched in September of 2023 with approximately 35 liters of helium, which has a projected lifetime of >4 years. When the liquid is depleted, the ADR enters a cryogen-free mode of operation, which can be sustained as long as the JT and other cryocoolers remain fully operational. Details of the ADR’s design and performance will be presented.
13093-231
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Adiabatic Demagnetization Refrigerator Controller (ADRC) in the XRISM Resolve instrument is an electronics box responsible for high-precision sub-K temperature readout and control of the multi-stage adiabatic demagnetization refrigerator subsystem to achieve a thermal stability better than 2.5 uK RMS (over a 10-minute interval) for the calorimeter detectors in both cryogen (liquid helium) and cryo-free modes. It also provides temperature monitoring and heater control for the aperture filters.
13093-232
Pre- and post-launch operation of the soft X-ray spectrometer "Resolve" on board the XRISM satellite
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Resolve onboard the XRISM (X-Ray Imaging and Spectroscopy Mission) is an X-ray microcalorimeter detector being developed in Japan, the United States, and Europe. The XRISM satellite was launched on September 7, 2023, from the Tanegashima Space Center. Resolve fully met the energy spectral performance requirement (7 eV@6 keV) both on the ground and in orbit, and was confirmed to have the same performance as the SXS onboard the ASTRO-H (Hitomi) satellite. The Resolve is operated at a low temperature of 50 mK to achieve the required energy resolution with a cooling system to satisfy the lifetime requirement of over 3 years. We will report on the details of the series of pre-launch and post-launch operations during the critical phase to work the cooling chain.
13093-233
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Resolve instrument onboard XRISM hosts an X-ray microcalorimeter detector, which is expected to achieve a high-resolution (≤7 eV@6 keV), high throughput, and non-dispersive spectroscopy over a wide energy range (0.3-12 keV). Event screening to discriminate X-ray events from noise is important for the instrument to work in a large dynamic range of energy and flux. We obtained new data sets with an extended ground calibration program and in-orbit data, which we used to verify and optimize the screening criteria. We examined screening based on (1) the good-time-intervals, (2) relative event timing, and (3) pulse shape. The screening results are presented and the optimized parameters are implemented in the calibration data base.
13093-234
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Accurate and precise gain drift correction is the key to achieve the required energy resolution of the Resolve spectrometer on the X-Ray Imaging and Spectroscopy Mission (XRISM). Modulated X-ray sources (MXS) will be used for monitoring the in-orbit gain drift. However, complexities with both the MXS characteristics and the on-board pulse processing make optimization of the MXS setting challenging.
The MXS count rate model has been established using measurements in the spacecraft thermal vacuum test with the flight detector and MXS, which enabled us to choose a few optimal settings for the continuous operation of the MXS and to design and implement an alternative gain tracking approach called the intermittent operation.
In this presentation, we will report the strategies for the in-orbit gain tracking using the MXS and early results obtained in the orbit.
13093-235
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We report the results from the ground and on-orbit verification of the XRISM timing system when the satellite clock is not synchronized to the GPS time. Using the thermal vacuum test data obtained in 2022 August, we have confirmed that the accuracy of the absolute time satisfies the requirement (350 us) in the GPS unsynchronized mode. On-orbit tests were also performed in 2023 September and October as part of the bus system checkout after the launch. The clock frequency versus temperature trend was found to remain unchanged from that obtained in the ground test and the observed time drift was consistent with that expected from the trend.
Show Abstract +
The X-ray Imaging and Spectroscopy Mission (XRISM),launched on 7th September 2023, is carrying two X-ray telescope systems. One of them is Xtend which has a wide field of view of 38 arcmin squared, and provides spectroscopic imaging in the 0.4-13 keV band. The Xtend Transient Search (XTS) program executes searches for transient sources using the field of view of Xtend. If the XTS detects the transient events, it is quickly to be reported to the world via a telegram such as the Astronomer's Telegram (ATel) or the Gamma-ray Coordination Network (GCN). This search is to be conducted at least once a day. In this presentation, the framework of XTS, its operation method, the specific system of exploration, and the current status of the search will be reported.
13093-237
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Ground-based calibration of the X-ray Mirror Assemblies (XMAs) of the XRISM satellite was performed at the X-ray beamline at NASA’s Goddard Space Flight Center. A raytracing simulator has been developed by the HITOMI and XRISM teams and tuned to reproduce the calibration data. In this paper, we first give an overview of the ground calibration results obtained from raster scans and local spot scans. We then present the process used to tune the simulator parameters in order to match the calibration measurements. Finally, we show a comparison of the simulated results with the measured effective areas, vignetting curves, and point spread functions.
13093-238
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The X-ray Imaging and Spectroscopy Mission (XRISM) was launched on Sep 7, 2023 from Tanegashima Space Center in Japan. One of the instruments, Resolve, has a liquid helium dewar and mechanical cryocoolers that serve as heat sinks for the Adiabatic Demagnetization Refrigerator (ADR) which cools the microcalorimeter detectors to 50 mK. The liquid helium and the series of cryocoolers serve as complimentary, semi-redundant cooling systems. To maintain its temperature below 1.2 K the liquid helium slowly boils off. Using available instrumentation it is important to determine when the liquid helium will be exhausted to plan the mission. The methods to determine liquid helium volume on the ground included a superconducting level detector and ADR mass gauging. We used measured boil off rate and thermal models to interpolate between infrequent direct volume measurements. On orbit the ADR mass gauging is used. We also used the tank temperature and temperature drop across the porous plug, comparing ground tests and on-orbit results. This paper describes these methods and their limitations to determine the initial fill and boil off rate of the liquid helium before and after launch.
13093-239
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Resolve x-ray imaging spectrometer onboard the X-ray Imaging and Spectroscopy Mission (XRISM) consists of a 36 pixel array of high-resolution x-ray microcalorimeters with ~ 5 eV FWHM spectral resolution in the 0.3-12 keV band. The response to monochromatic x-rays (line spread function, LSF) is composed of a Gaussian core, and three weak extended components caused by energy loss during thermalization: an exponential tail, fluorescence escape peaks, and an electron loss continuum. We report on characterization of all of these elements in an extensive ground calibration campaign. We also discuss characterization of on-orbit performance, which is similar to that obtained on the ground, but with differences in the Gaussian core due to the on-orbit noise environment as well as the impact of cosmic rays.
13093-240
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The low temperature stages of the Resolve instrument, operating around 50 mK, are susceptible to interference from the instrument’s cryocoolers. Adjustment of the drive frequencies for the Joule-Thomson cooler (~52 Hz) and the Stirling coolers (~15 Hz) while measuring key parameters has proven an effective method to distinguish good from bad operating frequencies and pairs of frequencies. This paper describes the cryocooler frequency scan measurements and compares the results during instrument commissioning to those performed during ground tests.
Session PS7:
Posters - Missions
19 June 2024 • 17:30 - 19:00 Japan Standard Time
13093-71
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Hot Universe Baryon Surveyor (HUBS) mission will carry a nested X-ray telescope for covering an energy range from 0.5 keV to 10 keV to study the hot baryon evolution. In this paper, we report the last progress of the nested X-ray telescope. For HUBS mission, a three-stage conic-approximation type has been designed, which could simplify the manufacturing process. Then the substrate of the reflective mirror is made by thermal glass slumping technology. The coatings are characterized by a roughness RMS of 0.3 nm, as well as expected high reflectivity and good thermal stability. In addition, the in-situ measurement system program was developed to guide the telescope assembly process, providing a high reliability.
13093-241
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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HiZ-GUNDAM is a future satellite mission designed for exploring the early universe using Gamma-ray Bursts (GRBs). The satellite is equipped with three main instruments: Wide Field X-ray Monitors (WFXMs), a Near Infrared Telescope (NIRT), and its Mission Data Process Unit (MPU). When a transient source occurs and the X-rays enter the WFXM, a cross-shaped image is produced on the focal plane image sensor. Once the WFXM’s data are sent to the MPU, the direction of the source is determined from the center position. Furthermore, if there is no known stellar object in that direction, the event is classified as a GRB. To develop the software for this series of judgments, we utilized actual LEO image data of a cross to verify how well the center position of the cross can be calculated. In this conference, I will introduce the development status of the GRB detection algorithm.
13093-242
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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HiZ-GUNDAM is a proposed satellite mission for JAXA to promote time-domain and multi-messenger astronomy as the main targets of gamma-ray bursts. As the mission payload, the wide field X-ray monitors consist of a lobster eye optics array and a focal imaging sensor. The field of view of the monitor is ~0.7 steradian in the soft X-ray band (0.4 – 4 keV). As the X-ray detector, the pnCCD detector fabricated by PNSensor Inc. can achieve our mission requirements, and we are developing an FPGA-based electronic system for the pnCCD.
Our bread-board model of the electronic system consists of (1) a FPGA board, (2) an ADC & driver board, (3) a Power supply board, and (4) a 96×192 pixel pnCCD read out by 4 CAMEX analog front-end ASICs. We have driven CAMEXs successfully by sending the test pulse. In this paper, we report the development status of pnCCD by our FPGA-based electronic system.
13093-243
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Gamma-ray bursts (GRBs) are the most luminous cosmic explosions, emitting energy on the order of solar masses over several tens of milliseconds to a few hundred seconds. HiZ-GUNDAM is a satellite mission designed to explore the early universe using GRBs as probes. It utilizes a wide-field X-ray monitor consisting of Lobster Eye Optics (LEO) and pnCCD, which detects and determines the direction of GRBs.
Our previous readout system consisted of a pnCCD Driver Board, an ADC Board, and an FPGA Board. Our previous readout systems supplied many voltages from DC power supplies, which was impractical. Therefore, we developed a Power Supply Board to generate and supply the necessary voltages from a limited number of power sources. In this presentation, we will introduce and evaluate the performance of the electronic boards we have developed and explain the results of pnCCD drive experiments using the newly constructed readout system.
13093-244
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We are developing a wide-field X-ray monitor onboard the HiZ-GUNDAM mission, which is a future satellite mission for observing gamma-ray bursts. The pnCCD detectors will be used as a focal plane detector. pnCCD has high sensitivity to low-energy X-rays and can achieve a high frame rate using column-parallel readout nodes. The performance evaluation of pnCCD detectors of a small-sized device will be reported for low-energy X-rays (0.4-4 keV) at a relatively high operating temperature of around -20 degrees Celsius.
13093-245
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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HERMES (High Energy Rapid Modular Ensemble of Satellites) Pathfinder is a space-borne mission aiming to observe and localise Gamma Ray Bursts (GRB) and other transients, based on a constellation of six nano-satellites flying in a low-Earth orbit (LEO). The 3U CubeSats, to be launched end-2024, host miniaturised instruments with a hybrid Silicon Drift Detector/GAGG:Ce scintillator photodetector system, sensitive to X-rays and gamma-rays in a large energy band.
The development of the HERMES constellation, the design of the payload with the particular detector choices, and the laboratory testing will be outlined. In particular, we will present the results of the detector calibrations and environmental tests, giving a complete picture of the current status of the mission.
13093-246
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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X-ray and gamma/ray spectroscopy can be used to assess the composition of planetary surfaces, which is a key ingredient for both studying the body origin and evolution and prospecting for its resources. The first is the goal of the ASI CubeSat mission TASTE, to visit the Mars moon Deimos, which hosts an X-ray/gamma-ray spectrometer derived from the instrument developed in the framework of the HERMES Pathfinder project for detection and localization of cosmic high energy transients. The unrivalled wide band from a few keV to several MeV and temporal resolution of a fraction of ms, the moderate energy resolution of 5%, lightweight and small volume (1.6 kg, 1U) make this instrument ideal for CubeSat and small lander applications for near Earth asteroid research and prospecting. During the journey to the target it can provide assistance for navigation using X-ray pulsars, thanks to its exquisite temporal resolution and good sensitivity.
Show Abstract +
The HERMES Technologic and Scientific Pathfinder project is a constellation of six CubeSats aiming to observe transient high-energy events such as the Gamma Ray Bursts (GRBs). HERMES will be the first space telescope to include a “siswich” detector, able to perform spectroscopy in the 2 keV to 2 MeV energy band. The particular siswich architecture, which combines a solid-state Silicon Drift Detector and a scintillator crystal, requires specific calibration procedures that have not been standardised. We present in this paper the HERMES calibration pipeline, mescal, intended for raw HERMES data energy calibration and formatting. The software is designed to deal with the particularities of the siswich architecture and to minimise user interaction, including also an automated calibration line identification procedure, and an independent calibration of each detector pixel, in its two different operating modes. The mescal pipeline can set the basis for similar applications in future siswich telescopes.
13093-248
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The pathfinders of the High Energy Rapid Modular Ensemble of Satellites (HERMES) are a constellation of low Earth orbit (LEO) nanosatellites devoted to the monitoring of high energy sky These 3U nanosatellites are equipped with miniaturized detectors specifically designed for bright high-energy transients, e.g. Gamma-Ray Bursts (GRBs). Their primary objective is to advance GRB science and improve the identification of Gravitational Wave (GW) electromagnetic counterparts. This paper discusses the design and functionality of the on-board scientific software that runs on the Payload Data Handling Unit (PDHU) on-board the HERMES missions, as well as the HERMES-detector on board the SpIRIT mission. Besides serving as the main interface between the payload and the satellite bus, the PDHU also manages the on-board control, monitoring and triggering of the scintillating crystal detectors. We discuss the on-board data processing executed by the PDHU and its tested/expected triggering performance based on the detector's data output prior to operations. We present the expected behaviours and different trigger-schemes to maximize the scientifc return of the HERMES mission.
13093-249
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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HERMES (High Energy Rapid Modular Ensemble of Satellites) Pathfinder is a space-borne mission based on a constellation of six nano-satellites flying in a low-Earth orbit. The 3U CubeSats, to be launched end-2024, host miniaturised instruments with a hybrid Silicon Drift Detector/scintillator photodetector system, sensitive to X-gamma-rays in a large energy band and will demonstrate the feasibility of gamma-ray burst detection and localization using miniaturized instruments onboard nano-satellites. The HERMES project is funded by the Italian Ministry of University and Research, by the Italian Space Agency, and by the EU Horizon 2020 Research and Innovation Program. In this paper, we present the implementation, testing, and performance assessment of HERMES's on-board gamma-ray bursts detection algorithms. Tests were performed on one of the HERMES payload flight models, under controlled laboratory conditions, using both synthetic data and a custom developed experimental set-up, to simulate burst and background photons. Various performance metrics are evaluated, including true and false detection rates, and the algorithms robustness to variations in background photon count rates.
13093-250
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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GRBAlpha is a 1U CubeSat launched in March 2021 to a sun-synchronous LEO at an altitude of 550 km to perform an in-orbit demonstration of a novel gamma-ray burst detector developed for CubeSats. VZLUSAT-2 followed ten months later in a similar orbit carrying as a secondary payload a pair of identical detectors as used on the first mission. These instruments detecting gamma-rays in the range of 30-900 keV consist of a 56 cm2 5 mm thin CsI(Tl) scintillator read-out by a row of multi-pixel photon counters (a.k.a. SiPM). The scientific motivation is to detect gamma-ray bursts and other HE transient events and serve as a pathfinder for a larger constellation of nanosatellites that could localise these events via triangulation.
At the beginning of 2024, GRBAlpha detected 94 such transients, while VZLUSAT2 had 73 positive detections, confirmed by larger GRB missions. Almost a hundred of them are identified as gamma-ray bursts, including extremely bright GRB 221009a and GRB 230307A, detected by both satellites. We were able to characterise the degradation of SiPMs in polar orbit and optimize the duty cycle of the detector system also by using SatNOGS radio network for downlink.
13093-251
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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HUBS is a proposed X-ray satellite project dedicated to addressing the “missing baryon problem”. Its payload incorporates TES microcalorimeters operating at sub-100 mK, making ADR a key technology for the HUBS mission. Currently, we are in the process of improving the performance of a two-stage ADR prototype, mainly to increase the hold time at the operating temperature by reducing heat load on the cold stage. The heat load optimization steps taken include properly heat sinking the Kevlar suspension and wiring, lowering the temperature of the first (GGG) stage, and improving the performance of the gas-gap heat switch. Meanwhile, we replace the previous CPA salt pill with a new FAA salt pill containing more moles of crystals, as FAA has more cooling capacity than CPA per mole in the temperature range of interest. In this contribution, we describe the performance improvement of the ADR prototype and present the test results.
13093-252
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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As a pathfinder for HUBS, Diffuse X-ray Explorer (DIXE) is a proposed X-ray spectroscopic survey experiment for the China Space Station. The detector assembly contains the transition edge sensor (TES) microcalorimeter and readout electronics based on the superconducting quantum interference device (SQUID) on the cold stage. TES and SQUID are both sensitive to the magnetic field, so a hybrid shielding structure consisting of an outer Cryoperm shield and an inner niobium shield is used to attenuate the magnetic field. From a zero-field cooling (ZFC) simulation using COMSOL Multiphysics, the shielding factor reaches 105-106, taking into account the necessary openings. Dynamically, field cooling (FC) process is simulated where magnetic field is found to be trapped inside the Niobium shielding. Helmholtz coils are utilized to counteract the initial magnetic field. A magnetic shielding prototype is built for verification. The performances are tested in both ZFC and FC processes. This paper will describe the design and verification of magnetic shielding for DIXE.
13093-253
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Frequency-division multiplexing (FDM) technologies are being developed for HUBS. As a first step, an FDM system is designed and implemented for its pathfinder (DIXE), which employs a 10x10 TES microcalorimeter array, achieving an energy resolution of 6 eV or better over an energy range from 0.1 to 10 keV. The system has a multiplexing factor of 25 within the 1-5 MHz bandwidth. This report presents the initial measurement results of both the warm electronics and the superconducting circuit, offering a comprehensive overview of the progress made. The findings support the conceptual viability of employing FDM for the multiplexed readout of TES microcalorimeters in the context of HUBS.
13093-254
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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HUBS mission is an innovative and important space science mission in the future. It will show us many unrevealed scientific problems of galactic cosmology. This mission will be carred out with a satellite, and some key technologies about mechanical and thermal designs are important for the wonderful performance of the scientific payload. This paper will introduce some items of the mission architecture, some of those solutions for the key technologies about mechanical and thermal designs will be discussed also.
13093-255
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Hot Universe Baryon Surveyor (HUBS) is a proposed space-based X-ray telescope for detecting X-ray emissions from the hot gas content in our universe. It employs X-ray microcalorimeters based on the MoCu transition-edge sensor (TES) technology, aiming at achieving an energy resolution of better than 2 eV over the 0.1-2 keV range with a 60 x 60 array. The design of the payload calls for microcalorimeters with a large absorber (of area 1 mm2). This work focuses on the design and fabrication of microcalorimeters based on MoCu TES and AuBi absorbers. Different designs for TES arrays with and without various size and pattern absorbers will be present here, as well as special considerations on increasing mechanical strength and lowering thermal conductivity.
Show Abstract +
HUBS employs X-ray microcalorimeters based on TES technologies, requiring an energy resolution of 2 eV or better over the energy range of 0.1–2 keV. In the development phase of the project, a variety of Mo-Cu TES testing devices have been fabricated in our lab, based on different designs. In this work, we will describe our measurement system, and show the test results on some of the devices, which are derived from R-T curves, I-V curves, complex impedance curves, and noise spectra. We will measure the energy resolution of devices with and without an absorber, with an optical laser system or an X-ray source. At present, with system readout noise down to 20 pA/sqrt(Hz), the energy resolution of the devices without an absorber is shown to be better than 1 eV; the characterization of those with an absorber is ongoing. The degradation of energy resolution due to thermal crosstalk is analyzed, and will be presented, along with mitigation measures taken.
13093-257
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present a Silicon Drift Detector (SDD) system for the Spectroscopy focusing array (SFA) onboard the enhanced X-ray timing and polarimetry (eXTP) mission. The SFA focuses on fast timing (time resolution below 10 μs) and good spectroscopic capabilities (energy resolution better than 180 eV at 6 keV). The sensor, consisting of 19 hexagonally shaped pixels with a total sensitive area of 5.05 cm², is connected to three High Time Resolution Spectroscopy (HTRS) Application-Specific Integrated Circuits (ASICs), which allow a fast readout of the detector signals. The detector works in a Charge Sensitive Amplifier configuration. We assembled a prototype detector module and report here its performance in terms of energy resolution.
13093-258
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Large Area Detector is built around an array of linear Silicon Drift Detectors read out by dedicated CMOS Application-Specific Integrated Circuits. Strict constraints on power consumption and energy resolution (200 eV FWHM at 6 keV for single-channel events, ≤ 240 eV FWHM overall), impose a tough trade-off. We developed a new sensor architecture to improve the performance following two strategies: firstly by confining the signal charge diffusion during drift to a single channel, and secondly by focusing this charge to a smaller anode reducing the preamplifier’s noise contribution. Preliminary results show single-anode events increasing from the original 40% to > 94%, with a significantly improved energy resolution.
13093-259
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Large Area Detector (LAD) is based of linear Silicon Drift Detectors (SDD) for space-borne spectral-timing studies in the 2–30 keV energy range, currently foreseen on board of the eXTP and STROBE-X (although with a different name, HEMA) space missions. Due to the harsh particle environment in a low Earth orbit, it will be subject to radiation damage in the form of both displacement damage and Total Ionizing Dose (TID). To evaluate the response of the LAD sensor technology to TID, we exposed a prototype of a LAD detector to a 60Co source for a total of 85 krad. Afterwards, a thorough study of the dependence of the damage-induced leakage current on the temperature was carried out. This allowed us to evaluate the contribution of TID to the end-of-life performance of the instrument.
13093-260
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Wide-Field Monitor is an array of coded-mask aperture cameras based on large-area linear Silicon Drift Detectors, operating in the 2-50 keV range. Each camera is designed to feature an instantaneous field of view of ~1 sr, a source location accuracy of ~1 arcmin, and a sensitivity (5σ) better than 5 mCrab in 50 ks. This instrument is currently part of the design of the eXTP, STROBE-X and LEM-X space missions. We are currently developing an end-to-end simulator to assess the scientific performances of the instrument as well as the algorithms for image reconstruction. Firmly rooted in the physics of photon-matter interactions, via both analytic and Monte Carlo algorithms, it is built according to a modular architecture to account for every subsystem involved in the generation of the signal. We present a few case studies where realistic fields of view are simulated through the camera, and analyzed via various techniques to assess its reconstruction and sensitivity performances.
13093-261
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Despite being a one-dimensional device by design, large-area linear Silicon Drift Detectors may exploit the diffusion of the charge cloud produced by an interacting photon to determine its two-dimensional impact position as well as its energy. Therefore, they can operate as spectral-imaging devices, which are particularly suitable for space-based X-ray coded-mask instruments, for which the trade-off between large collecting area, number of readout channels and spatial resolution is a challenge. We describe the experimental characterization of the photon reconstruction capabilities of a 169 µm-pitch large-area linear Silicon Drift Detector, whose technology is the foundation of the Wide Field Monitor camera of the eXTP, STROBE-X and LEM-X space missions.
13093-262
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The Large Area Detector is one of the narrow field of view instruments of the eXTP space astronomy mission, operating in the 2-30 keV range. Thanks to an array of 640 large-area linear Silicon Drift Detectors, it achieves a huge active area (> 3 m2 at 8 keV), and therefore cannot rely on grazing-incidence X-ray optics to its field of view. Instead, it features an array of lightweight collimator plates matched to the sensors, based on the technology of lead-glass Micro-Pore Optics. We developed a facility for the study and characterization of collimator plates, capable of measuring their point-by-point angular response about various axes at several energies with 1 arcmin accuracy and < 1% uncertainty. The facility is completed by a software pipeline that manages the measurements without constant user supervision, thus allowing thorough tests of the MPO samples.
13093-263
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
We have been developing X-ray optics on board FOXSI-4 and constructing our original ray-tracing simulator to quantitatively understand their performances. The simulator is essential to create response functions for analyzing actual observation data. Currently, we have confirmed the energy dependence of the absolute value of the on-axis effective area, as well as the relative values as a function of an off-axis angle and the consistency with actual data in the intensity distribution. Furthermore, the simulator was also used to determine design parameters in our stray light blocker system. In my poster, the details will be reported.
13093-264
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
FOXSI-4, a US-Japan joint-sounding rocket experiment, will be launched in spring 2024, targeting the world's first X-ray focusing-imaging spectroscopy of a large solar flare.
FOXSI employs Wolter type-I optics for high dynamic range. However, it reluctantly collects light even from outside of the field of view (FOV). To remove it, we designed a metal 3D-printed pre-collimator with a porous honeycomb structure. The holes are 0.7 mm in diameter, and 190mm deep, whose aspect ratio is 1:270. The wall thickness is 0.09 mm, ensuring an aperture ratio of more than 60% as a goal.
According to evaluation tests, the pre-collimator exhibited a 42% aperture ratio and a 1:367 aspect ratio. This aperture ratio was still comparable to the previous successful mission of FOXSI-3, and the FOV adequately covers the expected flare size. Thus, this collimator has enough capability for a flare observation and is adopted as a flight product.
13093-265
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
We have been developing our original X-ray optics for FOXSI-4, and ensuring vibration tolerance is one of the most important and difficult test items for optics. We designed mounting jigs to reproduce the required vibration level in 20-2000 Hz and finally reproduced the vibration spectra along three axes successfully. We conducted vibration tests for both flight model soft and hard X-ray optics along three axes, and a comparison of the imaging quality before and after the vibration showed no significant difference. Moreover, we evaluated the mechanical axes of the optics housing before and after the vibration tests. The results showed that the mechanical axes were consistent with each other within the repeatability. In this poster, we will introduce the details of our vibration tests.
13093-266
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
ECLAIRs is a coded mask hard X-ray telescope on-board the Sino-French SVOM space mission, sensitive in the 4-150 keV energy range. The camera is made of 6400 Schottky CdTe detectors organized in 200 hybrid matrices of 4x8 pixels, read by low-noise 32-channel ASIC chips. The detectors are polarized at -300 V and cooled at -20°C to minimize the leakage current. We describe the ECLAIRs instrument with a focus on the different steps of its integration and testing, and the main results obtained at each step. Finally, we have obtained an homogeneous detection plane with very good performance for 99,9% of the 6400 detectors.
13093-267
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The AstroParticle and Cosmology Laboratory is responsible for the coded mask subsystem of the ECLAIRs instrument, which is integrated into the SVOM mission. The ECLAIRs instrument is dedicated to the detection and location of gamma rays and X-rays in the energy band from 4 to 250 keV, and is being managed by the CNES. The mask pattern is determined by scientific criteria (location accuracy and sensitivity) and mechanical criteria (rigidity, mechanical strength, etc.).
The low threshold of 4keV means that the mask is self-supporting (the first time this has been done for a mask of this size). The mask has now been developed and the flight model has been delivered and integrated into the ECLAIRs instrument, which is due to be launched next year.
The aim of this poster is to present the geometry of the mask, the design choices, the manufacturing processes and the feedback from this assembly.
13093-268
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
We present here an STM32 microcontroller based on-board computer designed for use in
small satellites and CubeSat missions that was developed using commercial-off-the-shelf (COTS) electron-
ics components. An on-board computer (OBC) is one of the important subsystems of any CubeSat mission.
An on-board computer is the central brain of a CubeSat or small satellite, responsible for coordinating and
controlling various subsystems to achieve mission objectives efficiently and autonomously. It performs cru-
cial tasks like power management, communication, command and data handling, on-board data processing
and on-board software execution. This paper discusses the development of one such OBC designed for a
spectroscopic mission called Spectroscopic Investigator of Nebular Gas (SING).
13093-269
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The Swift Solar Activity X-ray Imager (SSAXI-Rocket) Instrument is a ride along instrument to the High Resolution Coronal Imager (Hi-C) Flare NASA sounding rocket launch campaign scheduled for the Spring 2024. In the short 5-minute rocket flight, SSAXI-Rocket will measure the soft X-ray near-peak emission phase of a large solar flare. SSAXI-Rocket combines small X-ray focusing optics and a high-speed readout detector, to image the flare with minimized image saturation and pixel signal blooming. These high-time cadence measurements can help uncover the soft X-ray intensity variations which can provide constraints on the intermittent heating processes in the flare magnetic loops.
13093-270
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The Lunar Electromagnetic Monitor in X-rays (LEM-X) is an imager for X-ray Astronomy to be installed on the surface of the Moon and is funded by the Italian Istituto Nazionale di Astrofisica (INAF) in the framework of the Italian "Piano Nazionale di Ripresa e Resilienza (PNRR)". The building block of LEM-X is represented by a pair of coded aperture cameras, each one built around four large-area linear Silicon Drift Detectors (SDDs) and able to image the sky within a field of view of ~1 sr with a source location accuracy of ~1 arcmin, while at the same time reaching a spectral resolution better than 350 eV FWHM at 6 keV. The LEM-X instrument preliminarly envisages about ten such camera pairs, arranged on a dome-like structure on the surface of the Moon, to reach a sensitivity better than 5 mCrab in 50 ks and 1 Crab in 1 s in the 2 -- 50 keV energy band.
In this contribution we describe the design of LEM-X, we discuss the scientific performance and we report the status of the instrument development.
13093-271
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The Rockets for Extended-source X-ray Spectroscopy (tREXS) are a series of sounding rocket instruments designed to detect diffuse soft-X-ray emission from astrophysical sources. tREXS house a multi-channel grating spectrograph that uses passive, mechanical beam shapers, arrays of co-aligned reflection gratings, and an extended focal plane based around Teledyne CIS 113 CMOS sensors. We present here an update on the instrument, results from the first flight, and a discussion of the future outlook.
13093-272
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
Contemporary x-ray missions frequently require large numbers of mirror or grating elements to make the observations necessary for their science. The parts must be produced under the various cost, schedule, and risk constraints of the programmatic opportunity. We will report on a generalization of the factory set-up problem and integrate that into a plan for advancing manufacturing readiness level. The paper will conclude with a discussion of how the manufacturing model can be used to design and manage to cost.
13093-273
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
Description of the SuperHERO (Super - High Energy Replicated Optics) hard x-ray telescope concept.
13093-274
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The upper atmosphere at an altitude of around 100 km has the least observational data of all atmospheres due to the difficulties of in-situ observations. Aiming to observe the density of the upper atmosphere, we are developing an X-ray camera dedicated to atmospheric observations to install on the exposed area of the International Space Station (ISS).
With the X-ray camera, we will observe the cosmic X-ray background (CXB) transmitted through the Earth rim, measure the absorption column density via spectroscopy, and thus obtain the density of the upper atmosphere.
The X-ray camera is composed of a slit collimator and an X-ray SOI-CMOS pixel sensor, and will stand on its own and make observations, controlled by a CPU-embedded FPGA "Zynq". We plan to install the camera on the ISS in 2025, when the sun will be at its maximum. In this presentation, the outline of the project and the development status will be reported.
13093-275
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
BlackCAT is a NASA-funded 6U CubeSat mission planned to be launch-ready in early 2025. BlackCAT will use its wide field-of-view and arcminute-scale localization to identify gamma-ray bursts (GRBs), gravitational-wave counterparts, and other high-energy transient events. The mission will send rapid alerts after detection of a transient event, enabling prompt follow-up from other ground- and space-based observatories. The science instrument is a coded aperture telescope, using a focal plane with four Speedster-EXD550 event-driven X-ray hybrid CMOS detectors (HCDs) and a gold-plated nickel coded mask to localize source positions. We describe methods and results for the calibration of the coded-aperture instrument using Penn State’s 47-meter X-ray beamline. We also briefly discuss plans for in-flight commissioning and calibration.
13093-276
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The CUbesat Solar Polarimeter (CUSP) project is a CubeSat mission orbiting the Earth aimed to measure the linear polarization of solar flares in the hard X-ray band by means of a Compton scattering polarimeter. CUSP will allow to study the magnetic reconnection and particle acceleration in the flaring magnetic structures of our star. CUSP is a project in the framework of the Alcor Program of the Italian Space Agency aimed to develop new CubeSat missions. It is approved for a Phase B study. In this work, we report on the accurate simulation of the detector's response to evaluate the scientific performance. A GEANT4 Monte Carlo simulation is used to assess the physical interactions of the source photons with the detector and the passive materials. Using this approach, we implemented a detailed CUSP Mass Model. We report on the evaluation of the detector's effective area, the modulation for polarized photons, and the spurious modulation due to the detector's geometry as a function of the beam energy.
13093-277
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The Rocket Experiment Demonstration of a Soft X-ray Polarimeter (REDSoX Polarimeter) is a sounding rocket mission that will make the first measurement of linear X-ray polarization below 1 keV. REDSoX's design uses Wolter I focusing optics and disperses the X-rays using critical angle transmission gratings. The dispersion of those gratings is matched to laterally-graded multilayers (LGML) such that the Bragg condition is satisfied across the 0.2-0.4 keV band, reflecting the linearly polarized x-rays efficiently onto our detectors. We will use three LGMLs arranged 120 degrees to one another to allow us to measure all three Stokes parameters at once. We expect to achieve a modulation factor of over 90%. Approaching two years since the project was selected, we present an update on our progress and challenges during the design phase, and also look ahead to an eventual launch in year five. REDSoX's goals are to train early career scientists and to serve as a technical demonstration for a possible orbital mission, the Globe Orbiting Soft X-ray Polarimeter (GOSoX).
13093-278
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
With the advent of sensitive gravitational wave (GW) and neutrino detectors, new messengers are available to study the Universe and its contents. To fully exploit the wealth of forthcoming discoveries by multi-messenger facilities, it is crucial to detect as many electromagnetic (EM) counterparts as possible.
3U Transat (3U cosmic TRANsient SATellites) is a French project for building a Low Earth Orbit (LEO) nano-satellites constellation to survey the high energy transient sky. Each science payload mimics a 1-D coded mask providing a 1-D localization by arranging in a cylindrical configuration 7 NaI(Ti) detectors of 8 cm long and Ø 1.2 cm coupled with silicon photomultipliers. In this talk, I will present the 3U Transat mission and its main scientific goals as well as the dynamical mission simulation we have built to assess the constellation performances as a function of multi-parameters .I will present highlights of the performance results.
13093-279
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
We are developing the Moon Moisture Targeting Observatory (MoMoTarO), a radiation instrument for neutrons and gamma rays to search for the water resources on the Moon. As the fast neutrons travel through the lunar soil, they are scattered by light elements such as hydrogen in water, losing energy, and becoming thermal and epi-thermal neutrons. The non-contact water exploration without excavation can be realized by measuring the difference in the number of thermal or epi-thermal neutrons depending on water content. The MoMoTarO can also challenge the basic science such as the gamma-ray burst observation and particle physics problems. We are now constructing the engineering model and demonstrating the performance of the MoMoTarO detector.
13093-280
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The simultaneous detection of both gravitational-waves (GWs) and the electromagnetic radiation counterpart from merging compact object binaries will provide a probe of the merger’s underlying physics, the nature of the progenitors, and the system’s post-merger state. BurstCube is a 6U (10 x 20 x 30 cm^3) CubeSat that will deliver the needed multi-messenger context for GWs by detecting, localizing, and rapidly disseminating information about short gamma-ray bursts (SGRBs) and other gamma-ray transients from across the full unocculted sky. BurstCube’s instrument consists of four Thallium-doped Cesium Iodide (CsI) scintillators coupled to banks of Silicon photo-multiplier (SiPM) arrays, and is sensitive to photon energies between 50 keV and 1 MeV. In this work we report on the outcomes of final instrument integration, testing, and pre-launch instrument performance of BurstCube.
13093-281
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Portable Lunar Observer for Volatiles, Environment and Resources (PLOVER) is a unique system derived from high TRL cubesat parts repurposed for the exploration of the Moon from orbit and / or the lunar surface. It is equipped with three primary instruments: (1) the Wideband Internal Neutron and Gamma-Ray Spectrometer (WINGS), a large volume high resolution gamma-ray and neutron spectrometer (1000 cubic cm); (2) the Regolith Fluorescence Experiment (ReFlEx), a Silicon Drift Diode Array sensitive between 0.2--20 keV; and (3) the Advanced Visible Infrared Analytical Spectrometer (AVIANS), a compact VIS/IR spectrometer sensitive between 300~nm and 2.5 μm.
The architecture of PLOVER is highly scalable and aims to: characterize lunar geology on global and local scales; conduct a search for resources on the lunar surfaces, including water; identify and characterize the transport of volatiles; and provide information on
the radiation environment encountered by astronauts. Currently it is designed for deployment and operation over all phases of the Artemis crewed Lunar expeditions.
13093-282
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
We present estimates of magnetospheric solar wind charge exchange soft X-ray events detectable with GEO-X. The OVII X-ray line flux was calculated using the latest calibrated ACE/SWICS data on solar wind O7+ ions and scaled to the sum of emission lines from other solar wind ions, based on past Suzaku magnetospheric charge exchange events. The instrumental background, including radiation noise mainly due to energetic protons, was estimated using GOES proton flux and our previously developed GEANT4 simulation. The number of detectable events meeting a criterion of S/N > 20 peaks around the solar maximum, reaching 43.7 events per year with an average duration of 6.96 hours. Assuming an observation efficiency of 30%, we found that at least one event can be detected within a 3-month timeframe with a 90% probability.
Show Abstract +
We have been developing an optical blocking filter for GEO-X which will perform soft X-ray imaging spectroscopy of Earth’s magnetosphere. GEO-X will provide an unprecedented view through X-ray observations in terms of the interaction between solar wind and magnetosphere. GEO-X consists of MEMS X-ray mirrors and a focal plane CMOS detector which is sensitive to visible photons necessitating a thin-film optical blocking filter to attenuate noise from out-of-band photons while providing high transmittance for in-band soft X-ray photons. Performance tests, e.g., acoustic testing, pinhole frequency and X-ray transmission measurements, and UV and atomic oxygen irradiation tests, were conducted and the detailed results will be reported.
13093-284
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
We have been developing ultra-lightweight Wolter type-I X-ray telescopes fabricated with MEMS technologies for GEO-X (GEOspace X-ray imager) which is a small satellite mission to perform soft X-ray imaging spectroscopy of the entire Earth’s magnetosphere. The telescope is our original micropore optic which possesses lightness (~5 g), a short focal length (~250 mm), and a wide field of view (~5 deg x 5 deg) and can satisfy stringent limits on mass and size. We report on fabrication methods, their optimization, subsequent imaging performances of the telescope, and results of environmental tests.
13093-285
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Solar X-Rays MOONitor is a project aimed at demonstrating the feasibility and the technological maturity of a lunar-based (part of the EMM – Earth Moon Mars mission) space weather monitor. This instrument benefits of the heritage of a commercially available X-Ray detector (Amptek FAST-SDD) already used in other space missions and of the experience gained during the characterization campaign performed for the Phase A of an analogous instrument (SolarX) whose purpose is to monitor the Sun activity in the 0.8-20 keV energy range from a sail-propelled cubesat (Helianthus).
The instrument will monitor the soft X-Ray Sun activity in order to timely detect and classify solar flares and anticipate the occurrence of Coronal Mass Ejections.
This paper reports the current and planned activities to implement the sensor’s readout functions in an FPGA-based space qualified electronics.
13093-286
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Swift Solar Activity X-Ray Imager (SSAXI-Rocket) sounding rocket experiment is a direct-imaging, soft X-ray telescope optimized for the observation of large (GOES C class-X class) solar flares. SSAXI-Rocket has high temporal resolution (>5 Hz) enabled by a fast-readout CMOS detector. A single Wolter-1 optic focuses light onto the detector plane. The optic has a 16” Half Power Diameter (HPD) angular resolution on-axis and an effective area of ~0.7 cm2 at 4.5 keV. The SSAXI-Rocket camera reads out spectrally integrated signal, and the system spatial resolution is designed to be < 16.7” HPD over the instrument field of view (> 20’ x 20’). The detector itself is a custom CMOS (2048 x 2048 pixels) with 10 um pixels. This report details our instrument design, and overviews the processes our team employed in telescope alignment, testing, delivery, and integration onto the Hi-C Sounding Rocket. We present the “as-built” projected flight performance of the delivered SSAXI-Rocket flight system, obtained by synthesizing the results of pre-flight subsystem testing and measurements performed during system integration and alignment.
13093-287
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The Line Emission Mapper (LEM) Probe concept will utilize a transition-edge sensor (TES) microcalorimeter to perform faint, diffuse X-ray observations in the presence of significant charged particle background. Achieving the needed sensitivity requires a ~14 cm^2 anti-coincidence (anti-co) detector with > 95% rejection efficiency and threshold below 20 keV. Our anti-co design employs parallel networks of quasiparticle-trap-assisted electrothermal-feedback TESs. We have developed multiple full-scale prototype anti-co detectors for LEM – both versions with Mo/Au TESs and with W TESs. Here we present the status of anti-co development and plans for continued maturation towards TRL-6, including detailed characterization of the low-energy threshold, rejection efficiency, and spatial discrimination ability. Broad energy range measurements have been performed (4.1 keV – 5.5 MeV) and demonstrate threshold and efficiency requirements can be achieved with this design. We also discuss modeling with G4CMP, a solid-state physics Geant4 add-on package, towards understanding phonon propagation and quasiparticle production in the detector, and compare the model to experimental results.
13093-288
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Line Emission Mapper (LEM) is a proposed NASA probe-class mission designed to study the formation of structure in the Universe. LEM will have a 14k pixel array of transition-edge sensor (TES) microcalorimeters that provide a spectral resolution of < 2.5 eV and a bandpass of 0.2-2 keV. In this paper, we report on the status and plan for continued development of the LMS microcalorimeter. This includes details of the TES and x-ray absorber design, and the measured performance in prototype arrays. We present a detailed budget for the energy resolution and show how the properties of the LEM pixels are well optimized for the baseline time-division-multiplexing (TDM) that will be used read out the array. Finally, we describe the design and performance of the first full scale LMS arrays which include the necessary mechanical and electrical interfaces needed for LEM and are a precursor to an engineering model detector.
13093-289
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We are developping space-qualified room-temperature digital readout electronics for the Line Emission Mapper (LEM) mission. LEM is a concept for a NASA X-ray probe designed for imaging and spectroscopy of large area low surface brightness X-ray emissions in the 0.2 to 2 keV range. The main detector is a hybrid transition-edge sensor (TES) array with a 30' x 30' outer array consisting of 2x2 Hydra 12,736 square pixels with a grid of 290 um and a 7' x 7' inner subarray consisting of 784 square pixels arranged in the center of the outer array with the same pixel pitch. The baselined readout technology for the total of 3,968 TES sensors is time-division multiplexing (TDM), which divides the sensors into 69 columns and 60 rows. At GSFC, we have developed a TRL-6 prototype of the room-temperature digital readout electronics and demonstrated a 2 eV full-width half-maximum at 6 keV for a 60-pixel co-added spectrum in a 2x32 TDM readout on the Athena-like TES array. In this presentation we show the demonstration of the electronics and its performance on a prototype LEM-like hybrid TES array.
13093-290
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The Line Emission Mapper (LEM) mission concept was developed in response to NASA’s 2023 Astrophysics Probe Explorer (APEX) Announcement of Opportunity. LEM is a large field of view (30’x30’), soft X-ray mission (0.2-2.0 keV) with a large format microcalorimeter X-ray imaging spectrometer in the focal plane (1.3-2.5 eV spectral resolution) that provides an unprecedented combination of grasp (the product of effective area and field of view) and spectral resolving power (E/dE ~ 80-1540) in this bandpass. LEM mission and science operations will follow the same successful approaches used by LM for 16 NASA missions and by SAO for 24 years of successful operations for one of NASA’s Great Observatories, the Chandra X-ray Observatory. In this paper, we discuss the design of the mission and spacecraft operations that supports the transformational science that LEM promises to deliver.
13093-291
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Line Emission Mapper (LEM) is a proposed NASA probe-class mission designed to understand the formation of structure in the Universe. LEM is a single instrument X-ray telescope consisting of an X-ray optic with a 4m focal length coupled to an X-ray microcalorimeter with a 30' field of view. The 10" half power diameter of the mirror is well matched to the 15" pixels of the LEM microcalorimeter spectrometer (LMS). The LMS consists of a 14K pixel array with a 5' central array of pixels with 1.3 eV FWHM energy resolution, surrounded by an array of "hydras" where 4 pixels are attached to a single transition edge sensor, providing 2.5 eV FWHM energy resolution. In this presentation, I will discuss how the LEM design is optimized to address key questions laid out by the 2020 Decadal Survey related to structure
formation and feedback in the Universe.
13093-292
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The Rockets for Extended-source X-ray Spectroscopy (tREXS) spectrograph is designed to detect diffuse soft-X-ray emission from astrophysical sources by utilizing a relatively large (~10 sq. deg.) field of view and moderate (R~50) spectral resolving power. The payload houses two coaligned optics channels that use passive, mechanical beam shapers, modules of reflection gratings, and an extended focal plane based around Teledyne CIS 113 CMOS sensors. The first flight of tREXS launched from White Sands Missile Range and targeted the Cygnus Loop supernova remnant. We present an overview of the component- and instrument-level alignment, calibration, and results from the first flight.
13093-314
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Lunar Electromagnetic Monitor in X-rays (LEM-X) is a proposed observatory on the Moon surface for the detection of transients and the long-term monitoring of astrophysical sources across the whole observable sky in the 2-50 keV band. LEM-X is based on a compact and lightweight coded-aperture camera with a 2-sr field of view. The detector plane is composed of four individual alumina-based Detector Assemblies (DA), each one hosting a single large-area (~7x7 cm2) linear Silicon Drift Detector (SDD), as well as 28 analog Application Specific Integrated Circuits (AFE ASICs), specifically developed for this project. High-voltage cables and a rigid-flex printed circuit board connect the DA to the back-end electronics and power supply. A breadboard featuring a 64-channel SDD and two AFE ASICs has been manufactured and is currently under test. The LEM-X DA is being developed within the Earth-Moon-Mars project of the Italian "National Recovery and Resilience Plan".
13093-315
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The Lunar Electromagnetic Monitor in X-rays (LEM-X) is a proposed observatory for high-energy transients to be placed on the surface of the Moon and it is being developed in the context of the Earth-Moon-Mars project of the Italian National Recovery and Resilience Plan. The fundamental components of the LEM-X instrument are pairs of compact and lightweight coded aperture cameras. In this paper, we present a tradeoff analysis ultimately aimed at defining the configuration of the experiment and its best location on the Moon surface. We first optimized the number and configuration of cameras and designed a concept of their support structure, to ensure best effective sky coverage while minimizing complexity, volume, and mass. Then, by using NASA’s SPICE toolkit, simulations were carried out to assess the effective sky coverage of the proposed instrument configuration across the lunar day, as well as the solar incidence angle. We provide results for a selection of potential lunar surface locations, along with considerations about thermal management and solar power. These initial findings lay the groundwork for future mission implementation studies.
Session PS8:
Posters - Gamma and Polarimetry
19 June 2024 • 17:30 - 19:00 Japan Standard Time
13093-293
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
AMEGO-X is one of the proposed MeV gamma-ray missions and its gamma-ray detector consists of silicon trackers and calorimeters. In order to efficiently detect MeV photons and to have precise Compton reconstruction, the silicon sensors must be fully depleted and have a good positional resolution (~500 um) with a good energy resolution. On top of that, the power consumption of the silicon detector must be low (< 1.5 mW/cm2). We have been developing AstroPix, an HV-CMOS active pixel sensor, to fulfill such requirements. Our latest AstroPix (ver.3) is the first full reticle chip designed to meet the requirements for both pixel pitches and power consumption. We report basic characterization of AstroPix-v3 such as I-V, noise, energy calibration/resolutions, dynamic range, and indirect depletion depth measurements using gamma-ray sources. We also present the status of a 2×2 array of AstroPix, Quad-chip, which is the smallest component of the silicon tracker.
13093-294
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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On August 27, ComPair was launched as a balloon payload from Ft. Sumner, NM and completed a 6-hour flight. ComPair is a prototype gamma-ray telescope for the development of key technologies for next-generation gamma-ray detectors. ComPair consists of four subsystems: a double-sided silicon strip detector tracker, a cadmium zinc telluride calorimeter, a cesium iodide calorimeter, and a plastic anti-coincidence detector (ACD). The ACD consists of 5 plastic scintillating panels, each optically coupled to 2 wavelength shifting (WLS) bars. Each WLS bar is read out with a 2x2 silicon photomultiplier (SiPM) array. In this proceeding, we detail the design and calibration of the ComPair ACD. We also report on the ACD’s veto efficiency and other performance metrics during the ComPair flight.
13093-295
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
We have developed a small liquid argon time projection chamber (LArTPC) called NanoGRAMS, whose fiducial volume is 5x5x10cm3. A LArTPC has advantages of dense and large volumes sensitive to MeV gamma rays compared with multi-layer semiconductor detectors or gaseous ones. The aim of our work is proof-of-concept studies for one of the important goals of Gamma-Ray and AntiMatter Survey (GRAMS). Our presentation focuses on MeV gamma-ray imaging, by allowing a LArTPC to work as a Compton camera. The NanoGRAMS measures scintillation light and ionized electrons generated by interactions of gamma rays and argon atoms, which are reconstructed to information on the initial energies and momenta of incoming photons. In this talk, we present the design of NanoGRAMS and the results of data analysis.t the design of NanoGRAMS and the results of data analysis.
13093-296
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The precise reconstruction of Compton-scatter events is paramount for an imaging medium-energy gamma-ray telescope. The proposed AMEGO-X is enabled by a silicon tracker utilizing AstroPix chips - a pixelated silicon HVCMOS sensor novel for space use. To achieve science goals, each 500x500um2 pixel must be sensitive for energy deposits ranging from 25 -700 keV with an energy resolution of 5 keV at 122 keV (<10%). This is achieved through active depletion of the 500 um thick sensor, although this deep depletion poses an engineering and design challenge. This talk will summarize the current status of depletion measurements highlighting direct measurement with TCT laser scanning and the agreement with simulation. Future plans for further testing will also be identified.
13093-297
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The ComPair balloon instrument is a prototype of the gamma-ray mission concept called
the All-sky Medium Energy Gamma-ray Observatory (AMEGO). AMEGO aims to bridge
the spectral gap in sensitivity that currently exists from ∼100 keV to ∼100 MeV by being
sensitive to both Compton and pair-production events. This is made possible through the
use of four subsystems working together to reconstruct events: a double-sided silicon strip
detector (DSSD) tracker, a virtual Frisch grid CdZnTe Low Energy Calorimeter, a CsI High
Energy Calorimeter, and an anti-coincidence detector to reject charged particle backgrounds.
Composed of 10 layers of DSSDs, ComPair’s tracker is designed to resolve the position of
photons that Compton scatter in the silicon, as well as reconstruct the tracks of electrons
and positrons from pair-production as they propagate through the detector. By using these
positions, as well as the absorbed energies in the tracker and 2 calorimeters, we can measure
the initial energy and direction of the incident photons. This proceeding will present the
development, testing, and calibration of the ComPair DSSD tracker before its balloon flight
in August 2023.
13093-298
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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GRBs are extremely difficult to pinpoint in space since they occur in random directions and last only a few seconds. Thus, GRB detectors require both a wide field of view and high angular accuracy. The optical counterpart of the short GRB170817 resulting from the first gravitational wave LIGO/VIRGO detection of a neutron star merger took ~11 hours to locate. To increase the detecting and localizing efficiency of GRBs, we introduce GALI - A GAmma-ray burst localizing instrument based on a novel concept of angle-dependent mutual obstruction between many small scintillators distributed within a small volume. Our new laboratory results show that GALI will provide prompt accurate directions of GRBs to within ~1° over the entire visible sky.
13093-299
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We report on the development of Glowbug-2: a gamma-ray transient instrument for the ISS. Glowbug-2 is the next iteration gamma-ray transient instrument being developed and built by NRL. This iteration follows the successful Glowbug instrument on the ISS [1], located on the JEM-EF through late 2024. Glowbug-2 consists of four large-area, panel scintillation detectors with edge SiPM read out, arrayed on the DOD STP H-11 pallet. The launch to the Columbus EPF on the ISS is expected in late 2025. The scintillation crystal detector units (CDU) are the same design as the units to be flown on the NASA StarBurst Multimessenger Pioneers mission, allowing Glowbug-2 to provide science enhancement and risk reduction for StarBurst. Each scintillation panel views the sky at a 45-degree angle (with respect to the pallet), with each facing orthogonal viewing directions, for all-sky coverage not occulted by the earth. During the presentation we will discuss the current instrument status.
[1] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
13093-300
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Semiconductor Compton telescope (SCT) is one of the promising technologies in cosmic MeV gamma-ray observation, because of good angular resolution measure thanks to its high energy and positional resolutions. However, it cannot be better than a few degrees because of quantum limitation. With improving sensitivity in MeV astronomy, realization of 10-arcmin-level of angular resolution is the essential. Since the mask made of heavy metal is a BGD source and the strong CXB limits the statistical significance of the mask decoding, we propose to adopt this concept on a narrow field of view Si/CdTe SCT, like the SGD onboard ASTRO-H mission. We developed a concept verification system, mini-SGI, adopting 0.5 mm thick DSSDs and 2 mm thick CdTe-DSD, covered with BGO active shield. We irradiated gamma-rays and verified the coded-mask and Compton reconstruction combined analysis.
13093-301
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The ComPair gamma-ray telescope is a technology demonstrator for a future gamma-ray telescope called the
All-sky Medium Energy Gamma-ray Observatory (AMEGO). The instrument is composed of four subsystems,
a double-sided silicon strip detector, virtual Frisch grid CdZnTe calorimeter, a CsI:Tl based calorimeter, and an
anti-coincidence detector (ACD). ComPair is designed to maintain continuous coverage from the Compton and
pair-production regime. The CsI calorimeter’s main goal is to measure the position and energy deposited from
the highest energy events. This design has a dynamic energy of 0.25-30 MeV. To demonstrate the instrument’s
maturity, ComPair was flown on a balloon flight in August 2023. This paper will present the results of the CsI
during the balloon flight where we observed background rates and gamma-ray lines from activation.
13093-302
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Compton Spectrometer and Imager (COSI) is a NASA Small Explorer mission set to launch in 2027, designed for an all-sky survey in the 0.2-5 MeV band. Its instruments are Germanium detectors surrounded by bismuth germanium oxide (BGO) shields, serving as an anticoincidence system (ACS) to reduce background events. MEGAlib is the Geant4-based reference simulation framework for COSI. Simulating scintillation processes within the shields is crucial for a realistic evaluation of the ACS detection efficiency, but including them in MEGAlib would dramatically increase the simulation time. We therefore propose the use of a response function derived from a dedicated Geant4 ACS simulation with full optical interaction. Verification and validation against analytical computations and laboratory measurements are presented. This setup is then applied to evaluate energy resolution and 3D light collection of the ACS, guiding the design of a prototype model for the response function.
13093-303
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The ComPair balloon instrument is a prototype gamma-ray telescope that aims to further develop technology for observing the gamma-ray sky in the MeV regime. ComPair combines four detector subsystems to enable parallel Compton scattering and pair-production detection, critical for observing in this energy range. This includes a 10 layer double-sided silicon strip detector tracker, a virtual Frisch grid low energy CZT calorimeter, a high energy CsI calorimeter, and a plastic scintillator anti-coincidence detector. The inaugural balloon flight successfully launched from the Columbia Scientific Balloon Facility site in Fort Sumner, New Mexico, in late August 2023, lasting approximately 5 hours in duration. In this presentation, we discuss ComPair’s development of the ComPair balloon payload, the performance during flight, and early results.
13093-304
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Compton Spectrometer and Imager (COSI) is a NASA Small Explorer Mission (SMEX) that will be launched into an equatorial low-earth orbit in 2027. The COSI instrument is a wide-field Compton telescope comprised of 16 germanium detectors that will survey the sky in the underexplored soft gamma-ray regime (0.2-5 MeV) to provide polarizations, spectrometry, and imaging of astrophysical sources. Instrument calibrations play an integral role in mission development as they are used to convert the measured detector parameters to the physical properties necessary for Compton reconstruction and to benchmark simulations. Calibrations directly impact the scientific return of the mission as the performance of the event reconstruction is limited by the accuracy to which calibrations were performed. In this work we will outline the COSI detector characterizations and instrument calibrations necessary to support COSI’s broad science goals.
13093-305
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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A next-generation medium-energy (100 keV to 100 MeV) gamma-ray observatory will greatly enhance the identification and characterization of multi-messenger sources. Coupling gamma-ray spectroscopy, imaging, and polarization to neutrino and gravitational wave detections will develop our understanding of various astrophysical phenomena including compact object mergers, supernovae remnants, active galactic nuclei and gamma-ray bursts. AstroPix is a monolithic HV-CMOS active pixel sensor which enables future gamma-ray telescopes in this energy range. AstroPix is capable of low-power (< 1.5 mW/cm^2), high spatial (500 um x 500 um) and spectral (< 10% FWHM at 122 keV) tracking of photon and charged particle interactions for Compton and pair-production imaging. A prototype multi-layered AstroPix instrument, called the AstroPix Sounding Rocket Technology Demonstration Payload (A-STEP) will be the first demonstration of AstroPix’s operation in a near-space environment. In this presentation we overview the design and state of development of the first AstroPix multi-layer payload.
13093-306
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Compton polarimeters are typically designed to be sensitive only to the azimuthal angle of the scattered photon, ignoring the scattering angle. Such a 2-dimensional reconstruction of the event is pursued for both simplicity and because the polarization of the incident photon influences only the former. While this is true for on-axis sources, when the source starts to be off-axis of several degrees the azimuthal response of the instrument is effectively a convolution of the azimuthal and scattering angles: measuring the latter would provide a better sensitivity and smaller systematic effects. In this contribution, we will present a design which allows to estimate the scattering angle in a Compton polarimeter through the read-out of the light signal at the two ends of scintillator bars. Such a design is being tested with a representative set-up and first results on the performance will be discussed.
13093-307
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The CUbesat Solar Polarimeter (CUSP) is a CubeSat mission to measure the linear polarization of solar flares in the hard X-rays band by means of a Compton scattering polarimeter. CUSP is a project in the framework of the Alcor Program of the Italian Space Agency aimed to develop new CubeSat missions. CUSP is approved for a Phase B study that will last for 12 month starting from the beginning of 2024. We report on the design solutions adopted for the most important design drivers of the payload. In particular, we report on the payload preliminary mechanical design (including the static and dynamic finite element analysis) and the preliminary thermo-mechanical analysis. Moreover, a topological optimization of the interface between the platform and the payload is discussed.
13093-308
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The CUbesat Solar Polarimeter (CUSP) is a CubeSat mission to measure the linear polarization of solar flares in the hard X-rays band by means of a Compton scattering polarimeter. CUSP is a project in the framework of the Alcor Program of the Italian Space Agency aimed to develop new CubeSat missions. CUSP is approved for a Phase B study that will last for 12 month starting from the beginning of 2024. We report on the characterization of the Avalanche Photodiodes (APDs) that will be used as readout sensors of the absorption stage of the Compton polarimeter. We assessed the APDs gain and energy resolution as a function of temperature by irradiating the sensor with a Fe55 radioactive source. Moreover, the APDs were characterized also coupled to a GAGG scintillator.
13093-309
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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New generations of 3D gas detectors are today available and applied, e.g., for tracking particles in the vertex detectors of accelerators. They apply the concept of Time Projection Chambers to 2D devices. TimePix3, or the most recent TimePix4, when coupled with a gas system, allows for 3D track reconstruction. Such capability promises to improve by far the sensitivity of the present 2D Gas Pixel Detector (GPD) on board the Imaging X-ray Polarimeter Explorer (IXPE), also solving the issue of its large dead time thanks to its parallel read-out. In this frame, we are developing a simulation software tool based on Geant4 to be used to develop these devices as a new generation of X-ray polarimeters for astrophysics. Moreover, a new read-out software capable of obtaining a 3D track reconstruction, taking advantage of the TimePix3 time capabilities and using the IXPE GPD legacy, has been developed, which helps improve the polarimetric sensitivity in view of future X-ray missions having on board this kind of detectors.
13093-310
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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IXPE is a mission of great success. It opened a window in X-ray astronomy but it is time to think to the future of this new discipline. IXPE legacy requires larger effective area, better Half Energy Width and larger energy band. New generation of high throughput/high performances X-ray optics are being manufactured making the current IXPE detector design obsolete. IXPE is barely capable to address key scientific cases such as the reflection features in X-ray binaries, from molecular clouds around the Galactic Center and in Radio-Quiet AGNs and imaging of non-thermal emission regions in Supernova Remnants. Polarimetry of jets cyclotron lines in neutron star X-ray binaries and hard tails in magnetars are still inaccessible.To exploit these optics, gaseous detectors with different thickness, pressures and gas mixtures and using ASICs of new generation with parallel readout and simultaneous information on time and charge for each pixel are available allowing for imaging of photoelectron tracks in 3-D. In this talk I will review how the main limitation of IXPE can be solved with current new generation of Gas Detectors discussing possible future X-ray polarimetry mission configurations.
13093-311
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Studying solar flares, Solar Energetic Particles events, and Coronal Mass Ejections is important for
heliophysics and Space Weather investigations. X-ray polarimetry allows us to evaluate the directivity of
electrons and the structure of magnetic fields by observing X-rays and the resulting polarization related
to the line-of-sight direction and magnetic field orientation. Several space missions have attempted to
measure the polarization of solar flares at high energy levels. New polarimetric missions based on
CubeSat have been proposed for the near future. This work discusses the possibility of adding imaging
capability to solar flare X-ray polarimetry using GridPix technology equipped with TimePix3/4 ASICs coupled to X-ray optics.
Lobster-eye optics design can capture the image of the entire Sun disc in a wide field of view at high
energy levels ranging from 10 to 30 keV. Due to the large flux of solar flares, the high-count rate
produced by such a configuration could be managed thanks to the fast TimePix3/4 ASICs characterized
by a very low dead time.
Conference Chair
SRON Netherlands Institute for Space Research (Netherlands)
Program Committee
Institut National de Physique Nucléaire et de Physique des Particules (France)
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