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Conference 13102
Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy XII
18 - 21 June 2024 | Room G318/319, North - 3F
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Tuesday Plenary
18 June 2024 • 08:30 - 10:00 Japan Standard Time | National Convention Hall, 1F
View Full Details: spie.org/AS/tuesday-plenary
13173-502
The present and future of Japan's space program
(Plenary Presentation)
18 June 2024 • 08:30 - 09:15 Japan Standard Time | National Convention Hall, 1F
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The Basic Plan on Space Policy sets forth the basic principles of Japan's space policy with an aim to promote policies for space development. The latest version, approved by the Cabinet in June 2023, marks a significant shift by defining space science as a crucial integral part of Japan's space development efforts, transitioning from treating it solely as an isolated academic activity. For instance, the Artemis program is promoted as a policy initiative where scientific exploration is positioned to serve a precursor role. It also encourages Japan’s involvement in NASA's post-JWST efforts. Here, I will present Japan's recent accomplishments and future plans in space science.
13173-503
NASA astrophysics: from today to the Habitable Worlds Observatory
(Plenary Presentation)
18 June 2024 • 09:15 - 10:00 Japan Standard Time | National Convention Hall, 1F
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The goals of the Astrophysics Division are to understand how the universe works, understand how we got here and to address the question, are we alone? In this talk, Dr. Clampin will discuss the current goals of the Astrophysics Division, and its suite of current and future missions. He will also preview progress towards the 2020 National Academies (NAS) Decadal Survey including the key recommendation, the Habitable Worlds Observatory and NASA’s approach to its implementation. Dr. O’Meara will discuss the first steps towards implementation, the formation of a Science, Technology, Architecture Review Team (START) and Technical Analysis Group (TAG) for HWO. He will describe how these teams, along with a large cohort of volunteers are working to define the trade space that must be explored for HWO to meet its top science goals of surveying exoplanets for the signatures of life and performing transformational astrophysics.
Break
Coffee Break 10:00 - 10:30
Session 1:
Imagers and Polarimeters I
18 June 2024 • 10:30 - 12:10 Japan Standard Time | Room G318/319, North - 3F
Session Chair:
Jian-Rong Gao, SRON Netherlands Institute for Space Research (Netherlands)
13102-1
18 June 2024 • 10:30 - 10:50 Japan Standard Time | Room G318/319, North - 3F
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We describe the design of the Next-generation Extended Wavelength MUltiband Sub/millimeter Inductance Camera (NEW-MUSIC), a first-of-its-kind, six-band submillimeter/millimeter-wave polarimeter covering 2.4 octaves of spectral bandwidth from 80 to 420 GHz. NEW-MUSIC will be deployed on the Leighton Chajnantor Telescope (LCT), the move of the 10.4-m Leighton Telescope of the Caltech Submillimeter Observatory to the Chajnantor Plateau in Chile. NEW-MUSIC will be ideal for measuring spectral energy distributions of synchrotron radiation and dust from a wide variety of time-domain sources and for studying the hot plasma in galaxy clusters and the circumgalactic medium via the Sunyaev-Zeldovich effects. NEW-MUSIC will use hierarchical, phased-array slot-dipole antennas, photolithographic, in-line bandpass filters, and microstrip-coupled, parallel-plate capacitor, lumped-element kinetic inductance detectors (MS-PPC-LEKIDs). Experimental results will include beam maps, spectral bandpasses, and noise-equivalent power, demonstrating the technology is ready for scale-up to a full focal plane and integration into NEW-MUSIC.
13102-2
18 June 2024 • 10:50 - 11:10 Japan Standard Time | Room G318/319, North - 3F
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Prime-Cam is a first-generation instrument designed for the Fred Young Submillimeter Telescope (FYST) in the Cerro Chajnantor Atacama Telescope (CCAT) Facility. Among the instrument modules being developed for the Prime-Cam receiver, the highest frequency 850 GHz module presents unique challenges in optical design, coupling, detection, and readout. The 850 GHz module will incorporate approximately 45,000 polarization-sensitive, lumped-element microwave kinetic inductance detectors (KIDs), which will represent the most KIDs on sky in a single instrument to date. We present the critical aspects of the detector design and discuss solutions to the challenges of efficient optical coupling and a multi-octave readout band. Specifically, the designs will include a feature which reduces the inductance across a portion of the detectors by shorting pairs of inductor lines to allow the KIDs to be tuned across four distinct bands across the readout range, all with minimal impact to the responsivity of the detector. We further present a comparison a comparison between simulations and preliminary results of thermal responsivity.
13102-3
18 June 2024 • 11:10 - 11:30 Japan Standard Time | Room G318/319, North - 3F
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The TolTEC Camera, mounted on the Large Millimeter Telescope (LMT), is a 3-band continuum camera and polarimeter operating at millimeter wavelengths. This paper reviews our progress on the camera commissioning and its inaugural scientific programs, spanning the 2022/2023 commissioning phases and reviewing the winter 2024 science program. We report on mapping speed estimations, optical performance, and the first scientific imaging and polarimetry findings. Additionally, advancements in out-of-focus holography and the integration of two novel maximum likelihood mapmakers are discussed. We conclude with scientific forecasts for the first four TolTEC Legacy Surveys and an overview of the initiatives aimed at facilitating public access to the camera and the broader LMT infrastructure.
13102-4
18 June 2024 • 11:30 - 11:50 Japan Standard Time | Room G318/319, North - 3F
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Microwave kinetic inductance detectors (MKIDs) are increasingly used in ground-based (sub)millimeter-wave astronomy experiments. Two existing challenges to operating detector arrays remain in selecting excitation tones for each MKID where there are hundreds of resonators on the same feedline or network and that will yield the best combination of linearity and sensitivity. This is further complicated when operating arrays at ground-based telescopes, where variations in background loading from the atmosphere can induce significant shifts in MKID resonant frequencies and affect quality factors. We describe a quantitative method for optimal tuning of MKID arrays under dynamic loading conditions. We apply this new readout tuning technique to the 1.1 mm MKID array of the TolTEC camera at the Large Millimeter Telescope, where we incrementally change the readout power applied to investigate its effect. We perform in lab optical characterization of a CCAT Observatory MKID array to investigate optimal tuning under different loading conditions.
13102-5
18 June 2024 • 11:50 - 12:10 Japan Standard Time | Room G318/319, North - 3F
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The BLAST Observatory is a proposed super-pressure balloon-borne submillimeter polarimeter designed for a future ultra-long duration balloon campaign from Wanaka, New Zealand. BLAST Observatory will have a 1.8m modified off-axis Gregorian optical system coupled to a 300L ^4He cryogenic receiver with 8,274 microwave kinetic inductance detectors (MKIDs) cooled to 100mK by an adiabatic demagnetization refrigerator (ADR) backed by a ^3He sorption refrigerator at 300mK and a liquid helium pumped pot operating at 2K. The detector readout will utilize a new Xilinx RFSOC-based system. With this instrument we aim to answer outstanding questions about interstellar dust dynamics and star formation as well as provide community access to the polarized submillimeter sky. The BLAST Observatory is designed for a minimum 31-day flight of which 70% will be dedicated to observations for BLAST scientific goals and the remaining 30% will be open to proposals from the wider astronomical community through a shared-risk proposals program. We will present the overall instrument design, current status, and recent progress with the optical design and metrology strategy.
Break
Lunch/Exhibition Break 12:10 - 13:20
Session 2:
CMB Instruments I
18 June 2024 • 13:20 - 15:20 Japan Standard Time | Room G318/319, North - 3F
Session Chair:
Giovanni Signorelli, Istituto Nazionale di Fisica Nucleare (Italy)
13102-6
18 June 2024 • 13:20 - 13:40 Japan Standard Time | Room G318/319, North - 3F
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Spider is a balloon-borne instrument designed to map the cosmic microwave background at degree-angular scales in the presence of Galactic foregrounds.
Spider has mapped a large sky area in the Southern Hemisphere using more than 2000 transition-edge sensors (TESs) during two NASA Long Duration Balloon flights above the Antarctic continent.
During its first flight in January 2015, Spider observed in the 95 GHz and 150 GHz frequency bands, setting constraints on the B-mode signature of primordial gravitational waves.
Its second flight in the 2022-23 season added new receivers at 280 GHz, each using an array of TESs coupled to the sky through feedhorns formed from stacks of silicon wafers.
These receivers are optimized to produce deep maps of polarized Galactic dust emission over a large sky area, providing a unique data set with lasting value to the field.
In this work, we describe the instrument's performance during Spider's second flight.
13102-7
18 June 2024 • 13:40 - 14:00 Japan Standard Time | Room G318/319, North - 3F
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GroundBIRD is a ground-based Cosmic Microwave Background (CMB) experiment for observing the polarization pattern imprinted on large angular scales (6 < ℓ < 300) at the Teide Observatory in Tenerife, Spain. Our primary scientific objectives are to prove inflation theory by detecting polarization signal imprinted by primordial gravitational waves generated during the inflation period and a precise measurement of the optical depth τ (σ(τ) ~ 0.01) to the reionization epoch of the Universe after Planck satellite at the first time.
GroundBIRD observes a large sky region (~40% of full-sky) while continuously rotating the telescope at a high speed of 20 rotation-per-minute to overcome the fluctuations of atmospheric radiation. We have adopted the NbTiN/Al hybrid type microwave kinetic inductance detector (MKID) as detectors. The MKID arrays (138 MKIDs for 145GHz and 23 MKIDs for 220GHz) were installed in May 2023. In this paper, we report the remote observation system and results of on-site performance verification tests of detectors and initial results.
13102-8
18 June 2024 • 14:00 - 14:20 Japan Standard Time | Room G318/319, North - 3F
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The Simons Observatory is a ground-based cosmic microwave background (CMB) survey experiment consisting of three 0.5 m small-aperture telescopes (SATs) and one 6 m large-aperture telescope (LAT), located at 5200 m elevation in the Chilean Atacama Desert. The LAT contains the 2.4 m diameter Large Aperture Telescope Receiver (LATR) and its 13 Optics Tubes with more than 62,000 Transition Edge Sensor (TES) detectors spanning six frequency bands between 27 GHz and 280 GHz. Once complete, SO will be the largest and most capable CMB observatory ever built, producing arcminute resolution maps over half of the microwave sky with unprecedented sensitivity. Extensive assembly, integration, and testing work was required to successfully deploy and commission the SO LAT and LATR, with first light expected before the end of 2024. Here we provide a detailed look at the deployment, commissioning, and operation status of the SO LAT and LATR.
13102-9
18 June 2024 • 14:20 - 14:40 Japan Standard Time | Room G318/319, North - 3F
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We present the laboratory performance of a 1,704-detector microwave SQUID multiplexed (μmux) Transition-Edge Sensor (TES) array and its accompanying RFSoC-based readout electronics after integration with AliCPT-1: a 72-cm aperture, two-lens refracting CMB polarization telescope, which will observe from the Tibetan Plateau beginning in 2024.
The first AliCPT-1 module incorporates two 4-6 GHz μmux readout lines, each with a multiplexing factor of 910, to readout 1,704 TES bolometers and additional dark channels. The module is probed via an RFSoC-based room-temperature electronics system, which combines all tone generation and processing procedures on a single piece of hardware.
Here we describe the integration of the module and electronics with the receiver and conduct end-to-end laboratory testing of their performance. Module measurements include spectra, optical efficiency, polarization efficiency, near-field beam maps, and sensitivity to external magnetic fields. We evaluate the behavior of the readout system during optical data collection, including its noise performance.
13102-10
18 June 2024 • 14:40 - 15:00 Japan Standard Time | Room G318/319, North - 3F
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LiteBIRD is a next-generation space telescope which aims to measure primordial gravitational waves in the polarisation of the cosmic microwave background. The level of the primordial (tensor, or B-mode) signal in relation to the scalar (or E-mode) only has a known upper limit, and the instrument requirement is to measure a tensor-to-scalar ratio sensitivity δr<0.001. Systematic effects arising from cosmic radiation are expected to play a significant role, and our prior work has focused on the development of an end-to-end simulation tool for evaluating the scale of this in LiteBIRD’s Low Frequency Telescope (LFT). We present an updated forecasting method which makes use of event tables generated by a new Geant4 mass model of LFT. We will compare the previously used simplified model with that of the updated mass model, and project these differences into an expected effect of the cosmic ray effect δr. Lastly, we will examine the use of a simple filtering method for removing direct detector impacts by cosmic rays, which have been shown previously to play the largest role in this systematic effect.
13102-11
18 June 2024 • 15:00 - 15:20 Japan Standard Time | Room G318/319, North - 3F
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Measurements of B-mode polarization in the cosmic microwave background (CMB) sourced from primordial gravitational waves would provide information on the energy scale of inflation and its potential form. To achieve these goals, one must carefully characterize the Galactic foregrounds, which can be distinguished from the CMB by conducting measurements at multiple frequencies.
BICEP Array (BA) is the latest generation multi-frequency instrument of the BICEP/Keck program, which specifically targets degree-scale primordial B-modes in the CMB. In its final configuration, BA will consist of four small-aperture receivers, spanning six different frequency bands. The BA4 receiver is designed to characterize Galactic dust at 220/270 GHz. This receiver is currently undergoing commissioning at Stanford and is scheduled to deploy to the South Pole during the 2024-2025 austral summer. Here, we will provide an overview of this high frequency receiver, discussing the integration status and test results as it is being commissioned.
Break
Coffee Break 15:20 - 15:50
Session 3:
New Instruments and Concepts I
18 June 2024 • 15:50 - 17:30 Japan Standard Time | Room G318/319, North - 3F
Session Chair:
Yoshinori Uzawa, National Astronomical Observatory of Japan (Japan)
13102-12
18 June 2024 • 15:50 - 16:10 Japan Standard Time | Room G318/319, North - 3F
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The AtLAST Consortium is working on an extensive plan and design study for a large, single-dish sub-mm observatory. Here we will present a sample of the detailed science case studies that we are refining in order to capture the telescope requirements. As a 50m telescope with a 2-degree field of view, the strength of AtLAST will be cases where a large field of view and sensitivity to large-scale structure is crucial, including multi-chroic imaging of our own Sun, mapping the dynamics of the galactic plane and making detailed measurements of the Sunyaev-Zeldovich effect. These science cases will require a suite of state-of-the-art instruments including high-resolution spectrometers, wide-field multi-chroic continuum cameras and integral field units. AtLAST aims to be a sustainable, upgradable facility that will ultimately deliver orders of magnitude increases in mapping speeds over current facilities.
13102-13
18 June 2024 • 16:10 - 16:30 Japan Standard Time | Room G318/319, North - 3F
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We demonstrate that a single 40-MHz repetition-rate mode-locked fiber laser can generate broadband phase calibration (PCal) signals and low-noise ~17-GHz local oscillator (LO) signals, both of which are required for the operation of the Korea VLBI Network (KVN) Yonsei Radio Telescope. The direct photodetection of a 40-MHz optical pulse train allowed the generation of flat RF comb signals with 40-MHz spacing up to the photodiode bandwidth (~50 GHz) for instrumental calibration required for multi-frequency VLBI investigations. At the same time, using a 5-stage fiber Mach-Zehnder interferometer pulse interleaver, we were able to generate the 16.64-GHz and 19.2-GHz low-noise single-tone LO signals required for downconversion of astronomical signals. With broader-bandwidth photodetectors, this system has the potential to be used for millimeter-wave signal generation, calibration, and downconversion for multi-frequency broadband radio telescopes.
13102-14
18 June 2024 • 16:30 - 16:50 Japan Standard Time | Room G318/319, North - 3F
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We present a plan for sub/millimeter-wave line intensity mapping (LIM) using an imaging spectrograph based on the Terahertz Integral Field Units with Universal Nanotechnology (TIFUUN) architecture. We aim to measure the dust-enshrouded cosmic star formation rate density within the first 2 billion years by conducting LIM observations of ionized carbon [C II] 158 μm and oxygen [O III] 88 μm lines, redshifted to sub/millimeter wavelengths. The proposed imaging spectrograph will simultaneously observe two frequency bands: Band-1 (139-179 GHz) and Band-2 (248-301 GHz). Each band will feature up to ∼100 imaging pixels (spaxels), with each spaxel having 100 spectral channels, providing a modest spectral resolution (R~500). The total number of detectors (voxels) will reach ~20,000. This dual-band configuration will allow simultaneous measurement of key spectral lines, e.g., [C II] 158 μm and [O III] 88 μm lines at z = 10.2 - 12.6, and CO(4-3), (7-6), [C I](1-0) and (2-1) at z = 1.9 - 2.2, enabling cross-correlation analysis. We will develop data-scientific methods to remove atmospheric noise using sparse modeling and to extract signals from the observed data using deep learning.
13102-15
18 June 2024 • 16:50 - 17:10 Japan Standard Time | Room G318/319, North - 3F
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Past millimeter-wave galaxy surveys have probed the brightest starburst galaxies only and suffered heavily from confusion. The interpretation of existing surveys has also been hindered by the lack of reliable redshift indicators for measuring distances for the entire sample. Thanks to recent advances in mm-wave detector technologies we can now overcome these limitations, and conduct the first truly volumetric surveys of star-forming galaxies at mm-wavelengths down to the L* luminosities of typical galaxies, with ~1000 redshift slices spanning most of the Cosmic star-forming volume (z ~1--12) with nearly uniform mass and luminosity selection. We describe an instrument concept capable of delivering such surveys with the technologies available today, which can be built and operated on a ground-based mm-wave facility in the near future. Such spectrometer cameras can resolve and redshift identify up to to 25,000 star-forming galaxies per year even when operated on a 10-m class telescope. On a larger aperture it can do the same faster or probe even deeper. We propose a loose, open-source collaboration to design, build, and operate one or several such cameras through the sha
13102-16
18 June 2024 • 17:10 - 17:30 Japan Standard Time | Room G318/319, North - 3F
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Scalable, densely packed spectrometer arrays (integral field units, or IFUs) would enable intensity mapping sensitive enough for precision measurements of cosmology and astrophysics in a new redshift regime. This scalability requires a new architecture, with spectrometers oriented parallel with incident light.
The key technology required is an inline waveguide-to-coplanar-waveguide transition. We present a millimeter-wave IFU concept that includes this new transition with on-chip kinetic-inductance-based spectrometers. The transition was designed with efficient Bayesian optimization and made robust to manufacturing tolerance with a novel optimization algorithm. It has >95% coupling over an octave bandwidth for 95% of randomly sampled transitions within tolerance. The design approach is of general interest to many instrument design problems; a Python implementation of the algorithm alongside an extension that automates a widely-used mesh-based EM solver are made publicly available. We also present the status of our efforts to fabricate transition prototypes in the 85--170 GHz band.
Wednesday Plenary
19 June 2024 • 08:30 - 10:00 Japan Standard Time | National Convention Hall, 1F
View Full Details: spie.org/AS/wednesday-plenary
13173-504
Euclid mission: first year of operations
(Plenary Presentation)
19 June 2024 • 08:30 - 09:15 Japan Standard Time | National Convention Hall, 1F
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After launch on 1 July 2023, the Euclid space telescope of the European Space Agency (ESA) has begun its 6-year mission designed to understand the origin of the Universe's accelerating expansion, which is commonly associated with Dark Energy. By observing billions of galaxies, Euclid will create a 3-dimensional map of the Universe covering 10 billion years of cosmic history. It contains the hierarchical assembly of (dark) matter in galaxies, clusters and superclusters telling us about the nature of gravity and giving us a detailed measurement of the accelerated expansion of the Universe in time. The stringent image quality and sky survey requirements impose extreme performances of the telescope, instruments, and spacecraft. After a mission summary, I will describe the in-orbit spacecraft and instrument performances. A notable challenge is the processing of the large volume of data. The scientific prospects of Euclid are illustrated with the first images and early science results.
13173-505
The ultraviolet explorer: new views of the UV universe
(Plenary Presentation)
19 June 2024 • 09:15 - 10:00 Japan Standard Time | National Convention Hall, 1F
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The Ultraviolet Explorer (UVEX) mission, scheduled for launch in 2030, advances three scientific pillars: exploring the low-mass, low-metallicity galaxy frontier; providing new views of the dynamic universe, and leaving a broad legacy of modern, deep synoptic surveys adding to the panchromatic richness of 21st century astrophysics. The UVEX instrument consists of a single module with simultaneous FUV and NUV imaging over a wide (10 sq. deg) FOV and sensitive R>1000 spectroscopy over a broad band from 1150 - 2650 Angstroms. In this talk I will describe the UVEX scientific program and provide an overview of the instrument and mission.
Break
Coffee Break 10:00 - 10:30
Session 4:
CMB Instruments II
19 June 2024 • 10:30 - 12:10 Japan Standard Time | Room G318/319, North - 3F
Session Chair:
Masashi Hazumi, High Energy Accelerator Research Organization, KEK (Japan)
13102-17
19 June 2024 • 10:30 - 10:50 Japan Standard Time | Room G318/319, North - 3F
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We present a thermal kinetic inductance detector array design for CMB polarization observation at 90/150 GHz bands. A horn-coupled planar ortho-mode transducer is used for a broadband linear polarization separation. The frequency separation is done using a fast roll-off lumped-element diplexer. Thermal kinetic inductance detectors with Al is used as the detector. The array has more than 450 optical pixels with more than 1800 detectors. The array design and preliminary measurement results will be discussed.
13102-18
19 June 2024 • 10:50 - 11:10 Japan Standard Time | Room G318/319, North - 3F
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Traditional methods of converting electronics readout counts to incident optical power on Transition Edge Sensors (TES) for Cosmic Microwave Background (CMB) observations involve a linear approximation. For the upcoming LiteBIRD CMB satellite, the strict non-linearity requirements cannot be met using hardware solutions alone and require a form of non-linearity correction. We present MNTES, a novel physics-based, non-linear calibration technique. This method leverages our physical understanding of the TES power balance equation, accounts for imperfect voltage bias by casting the bias network as its Thévenin equivalent, and can incorporate external parameters such as magnetic fields and focal plane temperature variations. The detector-specific parameters of MNTES will be measured during the ground calibration campaign prior to the LiteBIRD launch, yielding conversion functions that can take raw time-ordered data and output the reconstructed incident optical power. MNTES will allow us to achieve LiteBIRD’s goal of measuring the primordial tensor fluctuation spectrum to δr = 0.001.
13102-19
19 June 2024 • 11:10 - 11:30 Japan Standard Time | Room G318/319, North - 3F
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MISTRAL is a new 90 GHz camera that was installed in May 2023 at the Sardinia Radio Telescope, a 64m radio telescope in Italy. With MISTRAL, we aim to map the sky with a resolution of 12’’ and a high 4’ field of view, a capability only shared by few instruments in the world, unlocking the exploration of a wide range of science cases from the recently upgraded Sardinia Radio Telescope. The heart of MISTRAL is a focal plane populated with 415 cryogenic LEKIDs. These detectors are copuled with the telescope using a cold re-imaging optical system composed of two silicon lenses, producing a diffraction limited field of view of 4’. MISTRAL is now installed on SRT and is undergoing the technical commissioning, and will soon enter the scientific commissioning phase. In this contribution we will survey the subsystems of MISTRAL and their performance at the gregorian focus of the radio telescope, and report the first results of the technical commissioning.
13102-20
19 June 2024 • 11:30 - 11:50 Japan Standard Time | Room G318/319, North - 3F
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The payload module (PLM) of the next-generation CMB satellite LiteBIRD features three telescopes: a crossed-Dragone reflective Low-Frequency Telescope (LFT), and on-axis refractive Mid- and High-Frequency Telescopes (MFT and HFT), spanning 15 unique frequency bands from 34 to 448 GHz.
Central to the PLM are Transition Edge Sensor (TES) bolometers, maintained at a bath temperature of ~110 mK. They are coupled to the sky with silicon lenslets with metamaterial anti-reflection surfaces (LFT and MFT) and platelet-based horns (HFT). The cryogenic and room-temperature electronics translate the tiny thermal signals from TES bolometers into digital data at 18 GB/day. The PLM thermal management utilizes passively and actively cooled V-grooves and a series of coolers including a space-grade adiabatic demagnetization refrigerator. Polarization is modulated by continuously rotating achromatic half-wave plates held at around 10 K.
This design focuses on reducing systematic errors and enhancing stability. Combining systematic uncertainties, a statistical uncertainty of 2.2μK-arcmin in polarization, and margin, we will achieve a δr=0.001 precision on the tensor-to-scalar ratio r.
13102-21
19 June 2024 • 11:50 - 12:10 Japan Standard Time | Room G318/319, North - 3F
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We present the development of a breadboard model achromatic half-wave plate (AHWP) for the LiteBIRD Low-Frequency Telescope (LFT). LiteBIRD is an ISAS/JAXA strategic L-class satellite mission to probe the cosmic microwave background polarization. The polarization modulator unit (PMU) of the LFT uses an AHWP, which achieves an observational frequency coverage 34-161 GHz using a five-layer sapphire stack with a diameter of 330 mm based on the Pancharatnam recipe. The sub-wavelength structures on both end surfaces mitigate the reflection over broadband. Each sapphire is 4.9 mm thick, with a corresponding half-wave shift center frequency of 97.5 GHz. We use hydro-catalysis bonding to glue the sapphire surfaces and assemble the five-layer AHWP. The AHWP is successfully assembled. The measured transmittance and polarization properties are consistent with the theoretical prediction that neglects the effect of the bonding layer. In this presentation, we present the AHWP assembly, the polarimetric characterization, and the cryogenic and vibrational test results.
Break
Lunch/Exhibition Break 12:10 - 13:20
Session 5:
Detectors
19 June 2024 • 13:20 - 15:20 Japan Standard Time | Room G318/319, North - 3F
Session Chair:
Jason E. Austermann, National Institute of Standards and Technology (United States)
13102-22
19 June 2024 • 13:20 - 13:40 Japan Standard Time | Room G318/319, North - 3F
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We have obtained NASA funding to build and demonstrate Transition Edge Sensor (TES) based kilopixel arrays with the properties that match the requirements for cryogenic far-infrared space missions: the arrays are very closely tileable in one direction and have only a moderate gap in the other direction. This array architecture can meet the sampling- and pixel number requirement of ~ 104 pixels. Many details of the architecture have already been demonstrated individually, and the detector board will be optimized for the use of the latest cryogenic bump bonded NIST 2-D time domain SQUID readout multiplexers with a high density fanout scheme. Additionally, we use flex-lines that are very similar to those developed at Princeton University for the ACT project. We already have a pixel design that exceeds the continuum sensitivity requirements for a cryogenic space mission.
13102-23
19 June 2024 • 13:40 - 14:00 Japan Standard Time | Room G318/319, North - 3F
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We present preparation for fabrication and deployment of science-grade kilo-pixel Kinetic Inductance Detector (KID) based arrays for the Terahertz Intensity Mapper (TIM). TIM is a NASA-funded balloon-borne experiment planning its Antarctic flight for 2026. TIM employs two focal planes, each with four subarrays of ~900 hexagonal-packed, horn-coupled aluminum KIDs. Fabrication yield is high, and we have successfully mapped KID resonant frequencies to spatial locations with our LED mapper. The spatial and frequency information associated with every yielded pixel allows a study of spatial coincidences as cosmic rays interact with the array, as well as interpretation of a covariance analyses performed on the noise timestreams. We also describe the improvement on the science-usable yield of our 864-pixel array achieved by (1) the lithographic trimming that de-collides resonators, and (2) our characterization of interpixel crosstalk. This pioneering work on the postprocessing will pave the way for science with our large KID arrays.
13102-24
19 June 2024 • 14:00 - 14:20 Japan Standard Time | Room G318/319, North - 3F
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We present the first full-array optical characterizations of the 280 GHz aluminum-based superconducting microwave kinetic inductance detector (MKID) arrays developed at NIST, CO, USA for the CCAT Collaboration for observing galactic ecology, Sunyaev-Zel'dovich effect, galaxy evolution, and line intensity mapping. The main advantage of aluminum MKIDs is their lower 1/f noise compared to the alternative choice of titanium-nitride (TiN) MKIDs, which would reduce systematic drifts when mapping the sky. We will present the spectral response, polarization characteristics, detector efficiency, and noise equivalent power (NEP) under the relevant conditions for these detectors. Two aluminum and one TiN MKID arrays will form the detector arrays in the 280 GHz instrument module of the Prime-Cam. First light observations are expected in 2025.
13102-25
19 June 2024 • 14:20 - 14:40 Japan Standard Time | Room G318/319, North - 3F
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The MISTRAL instrument is a cryogenic, W-band camera consisting of 415 lumped element kinetic inductance detectors. In May 2023, MISTRAL was successfully installed at the Sardinia Radio Telescope, a 64 m aperture telescope in Italy. MISTRAL has a focal plane of ∼80 mm in diameter, resulting in an instantaneous field of view ~ 4 arcmin. To preserve the high angular resolution of the telescope, ~12 arcsec, the focal plane sampling has been tuned to 4.2 mm, corresponding to a pixel separation of ~10.6 arcsec. The remarkable combination of high angular resolution and wide instantaneous field of view makes MISTRAL an exceptionally versatile tool for millimeter-wave sky surveys. Its unique capabilities significantly enhance the observational capacity of the Sardinia Radio Telescope.
We discuss the design, electrical, and optical characterization of the detector array, placing specific emphasis on the yield, the pixel identification on the array, the optical performance, and the calibration procedures.
13102-26
19 June 2024 • 14:40 - 15:00 Japan Standard Time | Room G318/319, North - 3F
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Deposited dielectrics with low mm-submm loss will be of great benefit to on-chip superconducting circuits for mm-submm astronomy. Compared with planar chip designs, multilayer structures with deposited dielectrics allow for more compact circuit elements, and eliminate radiation losses at high frequencies. While recently hydrogenated amorphous silicon carbide has been demonstrated to exhibit low dielectric losses at mm-submm wavelengths, the origin of the mm-submm loss in hydrogenated amorphous silicon carbide remains unknown.
We measured the 270-600 GHz dielectric losses of hydrogenated amorphous silicon carbide in superconducting microstrip lines. Furthermore, we measured the complex dielectric constant of the hydrogenated amorphous silicon carbide in the 3-100 THz range using Fourier transform spectroscopy. We modeled the loss data from 0.27-100 THz using a Maxwell-Helmholtz-Drude dispersion model. Our results demonstrate that phonon modes above 10 THz dominate the mm-submm losses in deposited dielectrics.
13102-27
19 June 2024 • 15:00 - 15:20 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
The PRobe far-Infrared Mission for Astrophysics (PRIMA) is a future cryogenic space observatory that will revolutionize study of evolving galaxies and forming planetary systems with highly-sensitive far-infrared (far-IR) imaging and spectroscopy. PRIMA’s spectrometer, the Far-InfraRed Enhanced Survey Spectrometer (FIRESS), will deploy kilo-pixel aluminum kinetic inductance detector (KID) arrays covering wavelengths from 24-235 µm. Here we present optical characterization of a prototype FIRESS array operating at 25 µm. We have refined the fabrication process and now show astrophysical-background-limited sensitivity for FIRESS’s short-wavelength range. We measure an NEP below 3.5 x 10^-19 W/rtHz at 10 Hz and show that the device is photon-noise limited over six orders of magnitude in power, with individual 25 µm photons detected at the lowest powers. In addition, the detectors are highly stable, with flat NEP spectra under optical load down to 0.001 Hz.
Break
Coffee Break 15:20 - 15:50
Session 6:
Optics and Components I
19 June 2024 • 15:50 - 17:10 Japan Standard Time | Room G318/319, North - 3F
Session Chair:
Colm P. Bracken, National Univ. of Ireland, Maynooth (Ireland)
13102-28
19 June 2024 • 15:50 - 16:10 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
The optical coupling of detectors to telescope optics is a challenge for future far-infrared astrophysics observatories. The PRobe far-Infrared Mission for Astrophysics (PRIMA) collaboration has developed monolithic silicon microlens arrays for superconducting detector arrays spanning wavelengths from 24 to 261 microns. These custom-microfabricated lens arrays meet the stringent surface accuracy and roughness requirements that are necessary at PRIMA’s shortest wavelengths. Grayscale lithography is used in combination with deep silicon plasma etching to create arrays of three-dimensional lens profiles. This fabrication process generates highly uniform and accurate microlenses across a roughly 80 by 10 millimeter 1008-element array. The kilopixel microlens arrays are bonded to matching PRIMA detector arrays with a thin and uniform layer of epoxy. In this presentation, we report on the status and performance of PRIMA’s microlens fabrication and microlens-detector array hybridization processes.
13102-75
19 June 2024 • 16:10 - 16:30 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
We develop polarimetric detector arrays for submillimeter Space astronomy. The technology is based on the all-silicon bolometer scheme established for the Herschel/PACS photometer. Each pixel detects two orthogonal polarization directions with an efficiency greater than 95%. Every other pixel in the array is rotated by 45° to retrieve the linear Stokes parameter of the incident light inside the Airy disc of the telescope optics. We reduced the temperature to 50 mK to improve sensitivity and introduced new readout schemes based on single or double Wheatstone bridge configurations for fully differential DC outputs. The detectors are grown directly on a CMOS circuit wafer to ensure the largest bandwidth with the highest response.
13102-31
19 June 2024 • 16:30 - 16:50 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
We used laser ablation to fabricate sub-wavelength structure anti-reflection coating (SWS-ARC) on a 5 cm diameter alumina lens. With an aspect ratio of 2.5, the SWS-ARC are designed to give a broad-band low reflectance response between 110 and 290 GHz. SWS shape measurements give 303 micrometer pitch and total height between 750 and 790 micrometer height, matching or exceeding the aspect ratio design values. Millimeter-wave transmittance measurements in a band between 140 and 260 GHz show the increase in transmittance expected with the ARC when compared to finite element analysis electromagnetic simulations. To our knowledge, this is the first demonstration of SWS-ARC on an alumina lens, opening the path for implementing the technique for larger diameter lenses.
13102-32
19 June 2024 • 16:50 - 17:10 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
We design, fabricate, and measure a novel spectrometer based on meta-surface structures, aiming to optimize its spectroscopic resolution within a band from 1.7 to 2.5 THz. The latter corresponds to a bandwidth of 38%, being comparable with a grating spectrometer. The meta-surfaces apply unit cells that consist of double-anchor structures based on gold, polyimide and gold triple layers. Several quantum cascade lasers that operate at slightly different frequencies around 2.1 THz were used to validate the spectrometer. We have measured a resolving power R of 273 and an efficiency of 78 %. Our results demonstrate for the first time a centimeter-sized, light weight FIR spectrometer with a promising resolution, which has potential to replace the half meter-sized, heavy grating based spectrometers in this wavelength band.
Thursday Plenary
20 June 2024 • 08:30 - 10:00 Japan Standard Time | National Convention Hall, 1F
View Full Details: spie.org/AS/thursday-plenary
13173-506
Navigating the radio astronomy renaissance: challenges and opportunities for a sustainable future
(Plenary Presentation)
20 June 2024 • 08:30 - 09:15 Japan Standard Time | National Convention Hall, 1F
Show Abstract +
The next decade heralds a renaissance in radio astronomy, with a formidable complement of global Observatories, from LOFAR2.0, to the SKA becoming powerful discovery engines at these lowest frequencies. While they commit to lowering data access barriers, managing the deluge of data poses challenges, as the new constraint on viable astronomy must move from hours on sky to data product cost in energy, compute and carbon and data footprint. I will explore with you the challenges and opportunities in creating a new frontier of sustainable, ethical, affordable astronomy.
13173-507
The x-ray imaging and spectroscopy mission (XRISM): development and expected science
(Plenary Presentation)
20 June 2024 • 09:15 - 10:00 Japan Standard Time | National Convention Hall, 1F
Show Abstract +
The X-Ray Imaging and Spectroscopy Mission (XRISM) project was initiated in 2018 as the recovery mission resuming the high-resolution X-ray spectroscopy with imaging once realized but unexpectedly terminated by a mishap of ASTRO-H/Hitomi. XRISM carries a pixelized X-ray micro-calorimeter array and an X-ray CCD on the focal planes of two sets of X-ray mirror assemblies. The spacecraft was successfully launched from JAXA Tanegashima Space Center on September 7, 2023, and is now conducting performance verification observation followed by guest observations starting in August 2024. In this paper, we present the history of development and recent results.
Break
Coffee Break 10:00 - 10:30
Session 7:
Spectrometers I
20 June 2024 • 10:30 - 12:10 Japan Standard Time | Room G318/319, North - 3F
Session Chair:
Gordon J. Stacey, Cornell Univ. (United States)
13102-33
20 June 2024 • 10:30 - 10:50 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
We have created and demonstrated a Virtually Imaged Phased Array (VIPA) device for velocity resolved spectroscopy in the far-IR and will present the first cryogenic (LHe) measurements of the spectral profile of a prototype VIPA at 115 microns. A VIPA is a compact dispersive spectral filter that can deliver a spectrum with a resolving power of 100,000. Coupled to superconducting direct detection detectors, the VIPA promises unsurpassed sensitivity at velocity resolutions >3 km/s. Due to their compactness and absence of moving parts, VIPAs are a prime choice for balloon and space-borne astronomical spectroscopic, high-resolving power instruments like POEMM and FIRSST. The measurement was done using a custom testbed that included a THz Quantum Cascade Laser and pyroelectric detector. Our VIPA prototype achieved the designed resolving power of 15,000. We are now building an improved testbed to measure and characterize VIPAs with R=100,000 in the far-infrared and submillimeter regime.
13102-34
20 June 2024 • 10:50 - 11:10 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
Unveiling the emergence of massive/bright galaxies within the first 600 million years of the Universe is pivotal in astronomy. However, the mechanisms driving their rapid growth remain unclear. Millimeter/submillimeter spectroscopic observations of the far-infrared [OIII] and [CII] lines present a critical pathway to explore this. Here we present the science and development of FINER, a dual-polarization SIS mixer receiver for LMT exploiting ALMA's wideband sensitivity upgrade technology. Covering 120−350 GHz, FINER will offer 3−21 GHz IF per sideband per polarization and a 5x wider bandwidth than ALMA, promising an unparalleled spectral scanning capability in the northern hemisphere.
13102-35
20 June 2024 • 11:10 - 11:30 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
The South Pole Telescope Summertime Line Intensity Mapper (SPT-SLIM) is a pathfinder instrument that will observe on the 10-m South Pole Telescope in the 2024-2025 austral summer. The instrument consists of 12 dual-polarization pixels spanning 120-180 GHz with an R = 200 filterbank spectrometer coupled to aluminum kinetic inductance detectors. These spectrometers will be deployed in a compact 100 mK cryostat, located to intercept the main beam of the SPT without disturbing the SPT-3G experiment. The SPT-SLIM frequency range will be sensitive to the carbon monoxide (CO) line emission from high-redshift galaxies, paving the way for future high-redshift cosmology experiments. I will summarize the cryostat, optical design and commissioning status, present detector performance, and discuss the deployment and observation plans for the 2024-2025 austral season.
13102-36
20 June 2024 • 11:30 - 11:50 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
Following the discoveries of the Herschel space telescope and the numerous observations in the submillimeter range of the interstellar medium (ISM), we are developing two cryogenic spectrometer concepts that can be integrated on a detector focal plane to understand the evolution of the various phases of the ISM. In this talk, we present the principle and measured performance of those two multi-wavelength Fabry-Perot.
The first concept is an adjustable Fabry-Perot cavity with dielectric Bragg mirrors. This prototype, equipped with a piezoelectric mechanism is used to demonstrate the concept of a scanning Bragg mirror Fabry-Perot, enabling the spectrum around a line to be finely scanned without loss.
The second concept is a stationary array of Fabry-Perot made entirely of silicon. In this spectrometer, the cavity is made of microstructured silicon. By adjusting the size of the sub-wavelength structures, we change the optical index of the cavity and therefore the transmitted wavelength.
13102-37
20 June 2024 • 11:50 - 12:10 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
The Heterodyne Spectrometer Instrument (HSI) is one of two instruments designed for the recently submitted Far-IR Spectroscopy Space Satellite proposal to NASA. HSI stands out as the first heterodyne array receiver for a space mission. It covers a broad bandwidth range between 150 and 600 microns in just three bands, each equipped with two 5-pixel arrays. HSI facilitates dual-polarization, multi-pixel, and multi-frequency observations on a satellite, achieved through careful design and the utilization of low-heat dissipating, low-power, yet high TRL components. We provide details of the optical design and present a solution for thermal/background compatibility between the direct detector and heterodyne instrument.
Break
Lunch/Exhibition Break 12:10 - 13:20
Session 8:
Coherent Receiver Technology
20 June 2024 • 13:20 - 15:20 Japan Standard Time | Room G318/319, North - 3F
Session Chair:
Christopher E. Groppi, Arizona State Univ. (United States)
13102-38
20 June 2024 • 13:20 - 13:40 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
For a high-frequency radio interferometry system such as ngVLA, a high-frequency reference signal distribution can be advantageous. The reference signal is transmitted as a beat signal of dual-wavelength lightwave signal.
We propose phase compensation for the frequency transmission by offline processing as the same with atmospheric phase scintillation correction. Offline correction has advantages at cost-effectiveness and concern on feedback bandwidth which depend on delay of the transmission line.
In our fiber transmission scheme, the roundtrip phase of each lightwave of the dual-wavelength signal is measured independently, which provides accurate compensation for chromatic dispersion.
Experiments were conducted of 100-GHz transmission over optical fiber spools up to 400 km in length. Additionally, we made frequency transfer experiments using the installed fiber link and the fiber installed in the driving antenna.
Based on the results, we will report on the application possibilities and limitations of the proposed frequency transfer scheme.
13102-39
20 June 2024 • 13:40 - 14:00 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
We present a comprehensive characterization of the three 4×2 HEB mixer arrays developed for the Galactic/Extra-Galactic ULDB Spectroscopic Terahertz Observatory (GUSTO), a NASA balloon borne observatory. The arrays consist of spiral antenna coupled NbN HEB mixers combined with elliptical lenses. We report on the RF performance regarding sensitivity, IF bandwidth and LO power, including estimations of their performance in the GUSTO instrument pre-flight. Additionally, we also present the beam characterization of the different lens-antenna used. The beam co-alignment of the arrays is also discussed, where we achieved unprecedented accuracy. Our arrays were used in the GUSTO instrument which launched from Antarctica on the 31st December 2023 having a successful flight of 57 days, the longest ever recorded by NASA for such mission profile.
13102-160
20 June 2024 • 14:00 - 14:20 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
Spectroscopic observations of the far-infrared [OIII] and [CII] lines present a pathway to explore the mechanisms of the emergence of massive galaxies in the epoch of reionization and beyond, which is one of the most fundamental questions in astronomy. To address this question, the Far-Infrared Nebular Emission Receiver (FINER) project is developing two wideband dual-polarization sideband-separating heterodyne receivers at 120–210 GHz and 210–360 GHz for the Large Millimeter Telescope (LMT) in Mexico. Compared with Atacama Large Millimeter/submillimeter Array (ALMA), LMT provides 40% of ALMA’s light-collecting area and a similar atmospheric transmittance, but FINER plans to have an instantaneous intermediate frequency (IF) of 3–21 GHz per sideband per polarization which is five times wider than current ALMA’s bandwidth. Therefore, FINER is going to offer cutting-edge spectral scanning capability in the next several years. The project is currently in an active development phase. In this conference, the latest development status for FINER, including the optics, wideband waveguide components as well as low-noise superconductor-insulatorsuperconductor (SIS) mixers will be reported.
13102-41
20 June 2024 • 14:20 - 14:40 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
We have initiated an upgrade project for the existing Atacama Large Millimeter/submillimeter Array (ALMA) Band 8 (radio frequency: 385-500 GHz) receiver cartridge with a substantially improved second-generation version, referred to here as “Band 8v2”. Our primary goals for the ALMA Band 8v2 upgrade project are:
(a) To increase the IF bandwidth from the present 4 GHz per sideband per polarization (over an IF range=4-8 GHz) to 14 GHz per sideband per polarization (IF=4-18 GHz)
(b) To improve and flatten the TRX performance and IF power density slope across the full RF and IF ranges.
(c) To improve optics performance including cross polarization and aperture efficiency in the
instantaneous bandwidth.
In the conference, the project plan, receiver design, and its technical readiness will be presented.
13102-42
20 June 2024 • 14:40 - 15:00 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
We are developing a low-power-consumption microwave amplifier using superconductor-insulator-superconductor (SIS) mixers, indicating potential microwave power amplification when connected in cascade and driven by a local oscillator (LO) source. This amplifier shows promise for large-scale multipixel heterodyne SIS receivers and superconducting quantum computers. A proof-of-concept experiment with waveguide SIS mixer modules demonstrated an average gain of ~7.5 dB and a noise temperature of ~10 K at microwave frequencies, utilizing a W-band Gunn oscillator as the LO source. To enable amplifier chips for broader use, LO sources like Josephson oscillators are being explored. A designed waveguide Josephson array oscillator, connected to a waveguide SIS mixer module in a 4-K cryostat, showed clear photon-assisted tunneling steps, estimating a detected power of approximately 52 nW at around 100 GHz. Possible SIS mixer-based integrated amplifier chips will be discussed.
13102-43
20 June 2024 • 15:00 - 15:20 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
The ALMA Band-4+5 receivers are proposed for the upgrade after 2030. The new receiver will cover the RF frequency of the original Band-4 and Band-5 to reach 125 -211 GHz continuous frequency tuning over dual polarizations, dual sidebands with instantaneous intermediate frequency (IF) bandwidth up to 16 GHz per sideband and per polarization.
Both the HEMT-based receiver and SIS-based receiver schemes are considered. The system block diagrams, analysis of the specifications for the system and the key components, and the design roadmap will be presented. The key components with 51.2% relative bandwidth to be developed in-house are (i) RF InP HEMT LNAs, (ii) Nb SIS mixers, (iii) 3-dB waveguide hybrid couplers, (iv) orthomode transducers, (v) corrugated horn antenna, (vi) optics mirror pairs.
Break
Coffee Break 15:20 - 15:50
Session 9:
Detectors II
20 June 2024 • 15:50 - 17:30 Japan Standard Time | Room G318/319, North - 3F
Session Chair:
Johannes G. Staguhn, NASA Goddard Space Flight Ctr. (United States)
13102-44
20 June 2024 • 15:50 - 16:10 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
Future observatories for the far-infrared (FIR), such as envisioned in the NASA Probe announcement, will offer unprecedented sensitivity by using cryogenically cooled optics. Large arrays of lens-absorber coupled Microwave Kinetic Inductance Detectors (MKIDs) are the only candidate to fulfill the requirements for these observatories, requiring unprecedented sensitivity with a noise equivalent power below 10^(-19) W/√Hz while operating up to 12THz. The incoherent coupling mechanism of distributed absorbers leads to a robustness against misalignment, assembly, and fabrication issues at FIR wavelengths. In this contribution, we will present the design and fabrication of large arrays of lens-absorber coupled detectors and evaluate their performance at 7 and 12THz and demonstrate an NEP of 0.7⋅10^(-19) W/√Hz.
13102-45
20 June 2024 • 16:10 - 16:30 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
We present the design and optical characterization of a novel highly compact three-dimensional microwave kinetic inductance detector (3D-MKID). At short wavelengths, such as the far- and mid-infrared, the pixel density of MKID arrays is often limited by the size and geometry of each resonator’s capacitor. Sending the non-optically active component of the resonator into the third dimension minimizes the footprint of each pixel, allowing much higher array densities to be achieved. In our 3D-MKID design, we compactify the resonator by conformally coating deep-etched holes in the silicon substrate with superconducting films formed by atomic layer deposition. The resulting geometry consists of three-dimensional coaxial transmission lines, which are then connected to a meandered absorber on the substrate surface. An array of these resonators are capacitively coupled to a microstrip feedline. We present the characterization of a prototype 3D-MKID array and compare it to simulate resonator properties. We additionally describe the detector sensitivity performance when illuminated by a far-infrared blackbody source.
13102-46
20 June 2024 • 16:30 - 16:50 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
We are developing broadband metamaterial planar lenslet arrays for millimeter and submillimeter imaging using stacked silicon wafers patterned with subwavelength copper squares, deep reactive ion etched (DRIE) holes, or a hybrid combination of the two. Beam-forming is accomplished through spatial variation in refractive index within each pixel created by these subwavelength features, a gradient-index (GRIN) design. However, the optical properties of both the metal mesh and DRIE metamaterials exhibit dependence on polarization orientation and wavelength, posing challenges for lens design. We combine metal mesh and DRIE GRIN sections to leverage the contrasting polarization- and frequency-dependent properties of the two material types. Here we present measurements of our most recent prototype metamaterial GRIN lens on sinuous antenna-coupled TES detectors from 88 to 225 GHz. We also present design studies extending to higher frequencies and optimizing for different pixel pitches.
13102-47
CANCELED: Low Tc TiN Multilayer KIDs for the Far Infrared
20 June 2024 • 16:50 - 17:10 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
Low Tc (~650mK) TiN films exhibit 1/f noise knees around 0.1 Hz under optical load with time constants of 1 ms or longer, rivaling the time constants of aluminum detectors. These long-time constants make these sensors suitable for low NEP applications such as space-based astronomical missions. Additionally, because of the large normal state resistance and high kinetic inductance of TiN, direct absorption detectors can be made with smaller volumes (increasing their sensitivity) and smaller capacitors. We demonstrate this technology with measurements of optical efficiency and optical NEP on prototypes in the 350 um band. This will include feedhorn coupled direct absorption detectors with extremely small volumes of 1-10 um^3 and direct absorbing architectures requiring no focal plane optics with volumes of 10-100 um^3. Finally, we will present designs to scale this technology to a wavelength of 25 ums for potential use on a future FIR probe.
13102-193
20 June 2024 • 16:50 - 17:10 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
The goal of the PolarKID project is testing a new method for the measurement of polarised sources, in order to identify all the possible instrumental systematic effects that could impact the detection of CMB B-modes of polarisation. It employs the KISS (KIDs Interferometer Spectrum Survey) instrument coupled to a sky simulator and to sources such as point-like black bodies (simulating planets), a dipole (extended source) and a polariser. We use filled-arrays Lumped Element Kinetic Inductance Detectors (LEKIDs) since they have multiple advantages when observing both in photometry and in polarimetry configuration.
13102-48
20 June 2024 • 17:10 - 17:30 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
We present measurements of a polarization sensitive lens-antenna coupled MKID array at 1.5THz, mounted with an additional 20dB neutral density filter in a wide field camera. This allows full end to end system characterization with room temperature optical sources, but under similar optical loading conditions as expected in a space based polarimeter configuration.
The system is characterized using a wideband polarized photomixer based phase and amplitude beam pattern setup at 1.5THz. Two separate measurements with orthogonal source polarizations enable the co and cross polarization to be extracted, showing the full system low cross-polarization needed for many future polarimetric applications. Such a measurement setup is additionally of potential interest for the characterization of future missions (for example in the Far Infra-Red): to obtain the optical beam quality and verifying the optical interfaces on a component/sub-component level. We present and discuss this setup and the characterization of the lens-antenna coupled MKID camera.
Session 10:
New Instruments and Concepts II
21 June 2024 • 08:40 - 10:20 Japan Standard Time | Room G318/319, North - 3F
Session Chair:
Pamela D. Klaassen, UK Astronomy Technology Ctr. (United Kingdom)
13102-29
21 June 2024 • 08:40 - 09:00 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
Next generation far infrared instrument proposals for space missions present some interesting and challenging optical filtering requirements. There is a combined need for: shorter wavelength (down to 20µm) FIR filters and dichroics tailored for observational band selection; tight control of bandwidths and rejection of out-of-band radiation; and instrument thermal control.
Here we review the current state of the art for these devices for applications shorter that 200 µm (low-pass, high-pass and band-pass filters, polarisers, dichroics and beam-dividers); we discuss current developments and technological limitations and present solutions for future FIR instrument concepts.
13102-50
21 June 2024 • 09:00 - 09:20 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
The BISOU (Balloon Interferometer for Spectral Observations of the Universe) balloon-borne project, based on a Fourier Transform Spectrometer (FTS) operating between 90 GHz and 1.5 THz, is a pathfinder for a future space mission dedicated to the measurement of the CMB spectral distortions. After a successful CNES Phase 0 study, a new phase is starting with the development of a cryogenic breadboard. We describe here the latest results on the design of the instrument integrated inside the future gondola system. We also present the mission and flights parameters together with the expected sensitivity to CMB Compton y-distortion and the Cosmic Infrared Background measurements.
13102-51
21 June 2024 • 09:20 - 09:40 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
We present the on-sky commissioning and science verification of DESHIMA 2.0: the first science-grade integrated superconducting spectrometer (ISS) for ultra-wideband mm-submm spectroscopy. With an instantaneous band coverage of 205-392 GHz at a spectral resolution of F/dF = 500, DESHIMA 2.0 will be applied to emission line surveys and redshift measurement of dusty star-forming galaxies, spectroscopic Sunyaev–Zeldovich effect observations of galaxy-clusters, and other new science cases that utilize its ultra-wide bandwidth. Compared to its predecessor (DESHIMA 1.0), DESHIMA 2.0’s superconducting filterbank chip with a x4 higher optical efficiency, x4 wider instantaneous bandwidth, x20 faster position switching on the sky, and a remotely-controlled optics alignment system. DESHIMA 2.0 is currently installed on the ASTE 10-m telescope at 4860 m altitude with excellent sky transmission, and is being commissioned for science operation. In the conference we will report the on-sky performance and latest results in the science-verification campaign at ASTE.
13102-52
21 June 2024 • 09:40 - 10:00 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
Modern astrophysics requires complex instrumental configurations to reach the requirement of sensitivity, sky coverage, and multi-channel observations in the electromagnetic domain. An example is CONCERTO, which uses two arrays of KIDs coupled to a Martin-Puplett interferometer. CONCERTO has a wide instantaneous field of view (18.6 arcmin in diameter) and a spectral resolution down to 1.45 GHz in the 130-310 GHz electromagnetic band. The instrument was installed on the 12-m APEX telescope at 5100 m above sea level on the Chajnantor plateau.
The complexity of the experiment required the development of a fine instrument model to improve the performance and control the systematic errors in data.
We have created a numerical instrumental model to simulate the spectral-mapper configuration based on a Fourier transform spectrometer. We model the instrument noises, the sub-system characteristics, and the signal from the sky, exploiting physical data, models, and simulations.
In this work, firstly, we present the various sub-components of the simulation. Secondly, we simulate an on-sky observation and predict the spectral results. Finally, we compare with the actual observations.
13102-53
21 June 2024 • 10:00 - 10:20 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
In the effort to push the boundaries of radio astronomy observations, technological innovations are essential for future generations of observatories. This paper introduces an innovative design for future radio receivers in major observatories like ngVLA, ALMA, and SKA. The concept centers around an Octave Band Quad Ridge Feed Horn and Vacuum Window, designed to operate within the 25 to 50 GHz (2:1) frequency range. This cutting-edge feed model uses dielectric loading to enhance phase and polarization efficiency, thereby significantly increasing the overall aperture efficiency across the bandwidth. The dielectric rod, features a solid construction with comb-shaped ridges located in the throat of the feed horn. To complete the entire optic model an HDPE vacuum window with three custom designed antireflection layers to minimize the signal reflections, is designed and presented. To confirm the performance of the proposed model, we use two different 3D full-wave electromagnetic simulators, CST Studio Suite and HFSS. The results showcase a return loss exceeding 25dB with exceptional beam symmetry across the entire bandwidth.
Break
Coffee Break 10:20 - 10:40
Session 11:
Multiplexing and Readout I
21 June 2024 • 10:40 - 12:20 Japan Standard Time | Room G318/319, North - 3F
Session Chair:
Joshua Montgomery, t0.technology (Canada)
13102-54
21 June 2024 • 10:40 - 11:00 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
Increasingly large arrays TES bolometers continue to be planned for future mm-wave observatories, but their scalability is limited by the associated cryogenic multiplexing readout. Microwave SQUID multiplexing is a natural candidate for future systems, as it already boasts a ~10x channel handling advantage over other readout schemes due to its large available bandwidth. By further doubling this bandwidth, the demonstration we present increases the multiplexing factor from the prior best of 910 to 1,820 and enables a simple 1:1 pairing of detector components and multiplexer hardware. We show a yield of greater than 80% based on TES IV curve quality and model typical nearest-neighbor crosstalk to be ~0.4%. Finally, we estimate from measurements that only 3% of the total noise budget would result from the multiplexer if installed in a typical sorption-cooled ground-based receiver observing 60 degrees above the horizon with a zenith precipitable water vapor of 1.3 mm.
13102-55
21 June 2024 • 11:00 - 11:20 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
Kinetic inductance traveling-wave parametric amplifiers (KI-TWPA) offer wide instantaneous bandwidth, quantum noise limited performance, and high dynamic range, making them suitable for use in the readout of cryogenic detectors and superconducting qubits and a variety of applications in quantum sensing. This work discusses the design, fabrication, and measurements of a four-wave mixing microstrip KI-TWPA operating in the 4 - 8 GHz band. This frequency band is commonly used to read out cryogenic detectors such as microwave kinetic inductance detectors (MKIDs) and superconducting Josephson junction-based qubits. We report a measured gain of over 15 dB using four-wave mixing with a high dynamic range in the 4 - 8 GHz band. We also show the tunability of bandwidth by setting the pump-tone condition. Using a Y-factor method, we measure a near quantum limit KI-TWPA added noise in the 4 - 8 GHz band.
13102-56
21 June 2024 • 11:20 - 11:40 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
We present the design and testing of spaceflight multiplexing kinetic inductance detector (KID) readout electronics for the PRobe far-Infrared Mission for Astrophysics (PRIMA). PRIMA is a mission proposed to the 2023 NASA Astrophysics Probe Explorer (APEX) Announcement of Opportunity that will answer fundamental questions about the formation of planetary systems, as well as the formation and evolution of stars, supermassive black holes, and dust over cosmic time. The readout electronics for PRIMA must be compatible with operation at Earth-Sun L2 and capable of multiplexing more than 1000 detectors over 2 GHz bandwidth while consuming around 30 W per readout chain. The electronics must also be capable of switching between the two instruments, which have different readout bands,: the hyperspectral imager (PRIMAger, 2.5-5.0 GHz) and the spectrometer (FIRESS, 0.4-2.4 GHz). We present the driving requirements, design, and measured performance of a laboratory brassboard system.
13102-57
21 June 2024 • 11:40 - 12:00 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
RF-ICE is a signal processing platform for the readout of large arrays of superconducting resonators. Designed for flexibility, the system’s low digital latency and ability to independently and dynamically set the frequency and amplitude of probe tones in real time has enabled previously-inaccessible views of resonator behaviour, and opened the door to novel resonator control schemes. We introduce a multi-frequency imaging technique, developed using RF-ICE, which allows simultaneous observation of the entire resonance bandwidth. We observe that the multi-frequency imaging technique reveals a resonator response which is not captured by the frequency sweep measurement alone. We demonstrate that equivalent resonant frequency shifts can be achieved using either thermal, optical, or readout loading, and use this equivalence to counteract a change in thermal loading by digitally modulating the readout current through a resonator. We develop and implement a proof-of-concept closed-loop negative electro-quasiparticle feedback algorithm which first sets and then maintains the resonant frequency of a lumped element kinetic inductance detector while the loading on it is varied.
13102-58
21 June 2024 • 12:00 - 12:20 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
The t0.technology Control and Readout System (CRS) is a modular microwave control and readout system for mm-wave and radio astronomy, THz imaging, noise radar, and superconducting qubit control. The configuration discussed in this work implements firmware for readout of microwave Kinetic Inductance Detector (KID) arrays. The CRS can operate 4,096 KIDs over 2.5 GHz of complex bandwidth between 0–10 GHz, typically allocated across four independent RF chains at 1,024x multiplexing and 625 MHz of complex bandwidth each. Every CRS can operate as a standalone unit or collectively within one or more backplane-enabled subracks that distribute power, clocking, and synchronization, scaling to an arbitrary number of channels. Each fully populated subrack supports arrays of more than 65,000 KIDs. The signal processing and control software supports recent innovations in multi-probe measurements and dynamic feedback modes. The CRS has recently been selected as the new baseline readout system for the proposed South Pole Telescope instrument, SPT-3G+. We present the hardware design, firmware capabilities, open-source software, and the first laboratory characterization measurements.
Break
Lunch Break 12:20 - 13:40
Session 12:
Detectors III
21 June 2024 • 13:40 - 15:20 Japan Standard Time | Room G318/319, North - 3F
Session Chair:
Stephen J. C. Yates, SRON Netherlands Institute for Space Research (Netherlands)
13102-59
21 June 2024 • 13:40 - 14:00 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
Future far-infrared (FIR) astronomy missions will need large detector arrays with high sensitivity. Low noise detectors with a noise equivalent power (NEP) of 3×10−19 to 1×10−20 W/Hz1/2 for space-based continuum observations are needed, to be photon noise limited. Transition edge sensor (TES) as a type of sensitive low-temperature superconducting detector, has significant advantages in the measurement of broad band electromagnetic radiation, from millimeter waves to X-ray and gamma-rays. We propose a design of low noise TESs for FIR applications, with the NEP of lower than 3×10−19 W/Hz1/2. The key component on TES bolometer island is aluminum-manganese (AlMn) superconducting film, which has been proved that its critical temperature can be adjusted over a wide range by baking after the film deposition. We optimize the NEP of AlMn TESs by reducing the critical temperature to around 60 mK and designing the thermally isolating legs to reduce the thermal conductance effectively. The pixel design will be used as foundation in our future TES array designs and will benefit high-sensitive detector development.
13102-60
21 June 2024 • 14:00 - 14:20 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
We present the design and cryogenic characterization of highly sensitive 7 THz lens-antenna-coupled MKIDs for future actively cooled far-infrared space telescopes. This is the highest operating frequency ever demonstrated for antenna-coupled MKIDs. The detector is based on a broadband leaky-wave lens-antenna coupled to a hybrid (Al/NbTiN) CPW MKID. Both the antenna and the photosensitive Al section of the MKID lay on a thin dielectric membrane, improving both the antenna efficiency and the detector sensitivity. The high operating frequency requires the definition of sub-micron features with electron-beam lithography, pristine laser-ablated lenses, and very accurate alignments during assembly. We have tested a prototype chip and have obtained a detector noise equivalent power of 3e-20W/sqrt(Hz) with a high coupling efficiency. Additionally, we have measured the antenna beam pattern. With these measurements we demonstrate a detector system suitable for highly-sensitive (imaging) spectrometers.
13102-61
21 June 2024 • 14:20 - 14:40 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
We present recent progress in the development of ultra-low-noise Transition-Edge Sensors (TESs) pixels designed for far-infrared (~30-300µm) astronomical instruments. The TES sensitivity is maximized using phononic filters, which are sub-wavelength coherent filters that provide broadband rejection of thermal phonons emitted at the TES critical temperature, Tc~100mK. The phononic filter isolation legs are compact, ~50 µm. In a absorber-coupled bolometer suspended by four legs, the thermal conductance is reduced to achieve an NEP of less than 0.3 aW/rtHz, which is sufficient for balloon- and space-based imaging and low-resolution spectrometer instruments with cold optics. We discuss the phononic filter and TES design, the performance of the phononic-isolated TES pixels, and the advantage of these highly-sensitive absorber-coupled TES bolometers for astronomical instruments.
13102-62
21 June 2024 • 14:40 - 15:00 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
In this work we present the design, optimization and laboratory characterization of the array of kinetic inductance detectors for the 350GHz frequency band of the next--generation OLIMPO experiment, a 2.6m balloon-borne telescope intended to observe, with high-angular resolution, the millimeter and sub-millimeter sky from the Antarctic stratosphere. We showcase results of the electrical characterization (electrical responsivity and quasiparticle lifetime) and the optical characterization (optical responsivity and optical efficiency).
13102-63
21 June 2024 • 15:00 - 15:20 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
While large arrays of microwave kinetic inductance detectors (MKIDs) have been demonstrated with photon noise limited performance, imperfect frequency placement due to fabrication non-uniformity has led to resonators that collide with their frequency neighbors. Though physically yielded, the excess cross talk means that they are unusable for science applications. This would lead to reduced performance when placed on telescopes such as the CCATs FYST. However, we can use the LED trimming method developed at NIST to identify the non-uniformities, the resonator location to frequency correspondence, and then re-etch the resonators to correct them to an optimal position. This process has been demonstrated on a CCAT 280 GHz MKID array. We will show the results of the trimming of 3456 resonators on the array, and how the yield would be improved while maintaining the optical performance of the pixels. This demonstrates a path towards ideal wafer-scale MKID arrays.
Break
Coffee Break 15:20 - 15:50
Session 13:
Spectrometers II
21 June 2024 • 15:50 - 17:30 Japan Standard Time | Room G318/319, North - 3F
Session Chair:
Carole E. Tucker, Cardiff Univ. (United Kingdom)
13102-64
21 June 2024 • 15:50 - 16:10 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
Proposed for a late 2031 launch, PRIMA, the Probe far-Infrared Mission for Astrophysics, closes the gap between JWST and ALMA, offering unprecedented sensitivity and spectroscopic mapping capability in the 24-264 μm range for detailed studies of galactic evolution, planetary atmospheres, and dust-metal dynamics. Onboard PRIMA, the PRIMAger camera operates in the 25-80 μm bands utilizing advanced MKID detector modules for hyperspectral imaging enabled by Linear Variable Filters. This paper presents a graded resonant metal-mesh filter technology, demonstrating very promising efficiency in the short wavelength range. Overcoming dielectric loss limitations, an innovative dual-layer LVF design on thin membranes achieves a transmission of 80-90% at 12 THz. Rigorous electromagnetic modeling, optimization, and position-dependent spectral response measurements validate the filter performance. We present a comprehensive set of simulation and experimental results, including environmental pre-qualification tests, strongly supporting the suitability of this technology for future space applications.
13102-65
21 June 2024 • 16:10 - 16:30 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
The Epoch of Reionization Spectrometer (EoR-Spec) is an upcoming Line Intensity Mapping (LIM) instrument designed to study the reionization of the early universe (z = 3.5 to 8) by observing the redshifted [C II] 158 μm fine-structure line emission from aggregates of galaxies. EoR-Spec will be deployed on Prime-Cam, the direct-detection modular receiver for CCAT’s Fred Young Submillimeter Telescope (FYST). With an array of more than 6500 Kinetic Inductance Detectors (KIDs) illuminated by a 4-lens design, EoR-Spec will tomographically survey the E-COSMOS and E-CDFS fields for 4000 hours in the 210 - 420 GHz frequency range by means of a cryogenic, scanning Fabry-Perot Interferometer (FPI) with a resolving power of R = 100. Here we give an update on EoR-Spec’s final design and the current status of fabrication, characterization and testing.
13102-66
21 June 2024 • 16:30 - 16:50 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
Millimeter/sub-millimeter spectroscopy enables access to a vast cosmic volume through measurements of redshifted CII and CO rotation lines. This provides unprecedented opportunities to study large-scale structures and their evolution. As a recently advanced technology, the on-chip filter-bank spectrometer offers the advantage of reducing overall instrumental complexity. However, one challenge of the current design arises from the large footprint occupied by the filter bank, significantly diminishing pixel packing density on the telescope's focal plane. As the success of next-generation line intensity measurements relies on higher spectral resolution and improved array sensitivity, this presentation introduces a multi-level focal plane design aimed at substantially increasing pixel packing density. We build a prototype using feedhorn-coupled OMTs and optimize the design for typical filter bank geometries like those used for SPT-SLIM. The coupling between feedhorns and OMTs on different layers is simulated in COMSOL. We will present testing results of the prototype as a validation of the concept.
13102-67
21 June 2024 • 16:50 - 17:10 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
The Terahertz Intensity Mapper (TIM) is a NASA-funded balloon-borne telescope that aims to measure the [CII] emission from star forming galaxies over an enormous cosmic volume. TIM’s cryogenic receiver, based on the BLAST-TNG design, utilizes a three-stage He sorption refrigerator backed by a 280-liter liquid helium tank to achieve a base temperature of 250 mK, which enables photon noise-limited performance for its MKID detectors. Two low-impedance multi-channel heat exchangers enhance cooling efficiency, contributing to a designed hold time of 20 days under ground conditions. Preliminary simulations and assembly tests showcase the cryostat's reliability, and data validation is anticipated by the summer of 2024. We will present the design and current status of the TIM cryogenic receiver and our ongoing characterization effort toward an Antarctic flight in 2026.
13102-68
21 June 2024 • 17:10 - 17:30 Japan Standard Time | Room G318/319, North - 3F
Show Abstract +
For efficient spectroscopic redshift identification of early galaxies in the northern hemisphere, we aim to combine the Large Millimeter Telescope (LMT) with a wide-band heterodyne receiver, FINER, which will cover radio frequencies of 120–360 GHz and offer a 3–21 GHz intermediate frequency (IF) per sideband and polarization. To take full advantage of such wide IFs, we present a novel 10.24-GHz-wide digital spectrometer, DRS4 (Elecs Industry Co. Ltd.). It incorporates 20.48 Gsps samplers with an FPGA-based digital signal processing module. To mitigate the noise contamination from the image sideband, it is equipped with a digital sideband separation function to improve the sideband rejection up to 25 dB. Laboratory performance evaluations show that it exhibits an Allan time of at least ~100 seconds and a total power dynamic range of at least 7 dB. These results demonstrate its capability of instantaneously wide-band spectroscopy toward early galaxies with position-switching observations.
Session PS1:
Posters - Detectors I
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Tuesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13102-69
On demand | Presented live 18 June 2024
Show Abstract +
The goal of the PolarKID project is testing a new method for the measurement of polarised sources, in order to identify all the possible instrumental systematic effects that could impact the detection of CMB B-modes of polarisation. It employs the KISS (KIDs Interferometer Spectrum Survey) instrument coupled to a sky simulator and to sources such as point-like black bodies (simulating planets), a dipole (extended source) and a polariser. We use filled-arrays Lumped Element Kinetic Inductance Detectors (LEKIDs) since they have multiple advantages when observing both in photometry and in polarimetry configuration.
13102-70
On demand | Presented live 18 June 2024
Show Abstract +
Titanium Nitride is an ideal material for fabricating Kinetic Inductance Detectors (KID’s), firstly due to its relatively high and tuneable critical temperature, and secondly its high normal state resistivity, which allows for a large kinetic inductance and responsivity. However, fabricating large arrays can be challenging due to the films being very sensitive to changes in stoichiometry, thickness and contaminants. In this poster we show a novel method for making high quality films of superconducting TiN as well as pure Nb via the use of a High Impulse Magnetron Sputtering (HIPIMs) in a very high to ultra-high vacuum environment. We show that this method of sputtering can produce films of both TiN and Nb with exceptional uniformity and demonstrate Tc's of 3.3K and 9.2K respectively. In addition, we present RF measurements and analysis of KID arrays patterned into the films and discuss future directions for this work.
13102-71
On demand | Presented live 18 June 2024
Show Abstract +
The Simons Observatory (SO) is a ground-based experiment in Chile's Atacama Desert aimed at studying the early universe by measuring the cosmic microwave background (CMB) across 27 to 285 GHz. It includes three small-aperture telescopes (SATs) and one large-aperture telescope (LAT), with about 60,000 detectors offering angular resolutions from 1 to 90 arcminutes.
The LAT's low-frequency detector arrays use anti-reflection (AR) coated lenslet-coupled sinuous antennas and a diplexing filter for 27 and 39 GHz bands. Superconducting niobium (Nb) microstrip lines transmit signals to titanium (Ti) load resistors, which heat palladium (Pd) thermal ballasts sensed by transition edge sensors (TESs). These TESs, made from aluminum manganese (AlMn), operate at a base temperature of ~100mK.
The sensors are read out using cryogenic microwave resonators and RF superconducting quantum interference devices (SQUIDs) in a microwave multiplexing (uMux) scheme. This report covers the design, fabrication, and characterization of these low-frequency detectors by UC Berkeley.
13102-72
On demand | Presented live 18 June 2024
Show Abstract +
LiteBIRD, a forthcoming JAXA mission, aims to accurately study the microwave sky within the 40-400 GHz
frequency range divided into 15 distinct nominal bands. The primary objective is to constrain the CMB infla-
tionary signal, specifically the primordial B-modes. LiteBIRD targets the CMB B-mode signal on large angular
scales, where the primordial inflationary signal is expected to dominate, with the goal of reaching a tensor-to-
scalar ratio sensitivity of σr ∼ 0.001. LiteBIRD frequency bands will be split among three telescopes, with
some overlap between telescopes for better control of systematic effects. Here we report on the development
status of the detector arrays for the Low Frequency Telescope (LFT), which spans the 34-161 GHz range, with
12 bands subdivided between four types of trichroic pixels consisting of lenslet-coupled sinuous antennas. The
signal from the antenna is bandpass filtered and sensed by AlMn Transition-Edge Sensors (TES). We provide
an update on the status of the design and development of LiteBIRD’s LFT LF1 (40-60-78 GHz), LF2 (50-68-89
GHz) pixels.
13102-73
On demand | Presented live 18 June 2024
Show Abstract +
This work deals with the development of superconducting Kinetic Inductance Detectors (KIDs) for highly sensitive radio astronomy receivers within W-band (75 to 110 GHz). A bilayer based on superconducting titanium/aluminum (Ti/Al) thin films has been used for assessing its absorption performance in this frequency band at millikelvin temperature. A lumped-element inductor based on a 4th order Hilbert structure is designed to absorb the incoming radiation in two orthogonal linear polarizations. The development of a large-format camera prototype is presented. On one hand, ambient temperature quasi-optical characterization demonstrates a suitable absorption for both polarizations within the W-band. On the other hand, dark cryogenic characterization confirms the successful operation of the multiplexed KID devices providing high-quality factors and an operation yield of 97%. These results confirm these developments to be used in future polarimeter receivers.
13102-74
On demand | Presented live 18 June 2024
Show Abstract +
Double-Fourier interferometry (DFI) from a space-based platform provides a path to achieve broadband imaging spectroscopy in the far-infrared (FIR) with sub-arcsecond angular resolution. To provide further study of the technique and improve its technology readiness, we have constructed a laboratory-based DFI testbed. This instrument is coupled to a custom array of 25 feedback-controlled transition-edge sensor (TES) bolometers. We present the results of characterisation experiments to optimise the detector system as an integrated component of the DFI assembly. We demonstrate that tuning the PID-feedback control loops of the detectors and the timing of the multiplexed measurement process can modify the detector array's noise performance and speed of response to optical modulation for this purpose. From these, we have determined a set of optimised detector settings that reduce spectral noise in the spatial-spectral interferometer by 37--79%. In addition, we present further thermal characterisation of the detector array.
13102-76
On demand | Presented live 18 June 2024
Show Abstract +
DESHIMA 2.0 is an ultra-wideband submillimeter spectrometer based on integrated superconducting microstrip filters and Microwave Kinetic Inductance Detectors (MKIDs). We have demonstrated its ultra-wideband performance in the laboratory. The measured instantaneous frequency coverage with ~350 MKIDs is 205-392 GHz, with a mean filter Q of ~340. The broadband quasi-optical chain of the instrument is evaluated by sensitivity measurement with liquid N2, and beam-pattern measurement obtained simultaneously across the whole frequency range thanks to the combination of the multiplexing capabilities of MKID and a novel phase-amplitude beam measurement technique. The instrument has been deployed to the ASTE telescope in autumn 2023 for a commissioning and science verification campaign.
13102-77
On demand | Presented live 18 June 2024
Show Abstract +
Single photon detectors (SPDs) at terahertz (THz) waveband are necessary for the THz applications. The superconducting quantum capacitance detectors (QCDs) are proved to be ultra-sensitive at THz waveband. 1.5 THz single photon detection has been achieved. Besides their sensitivity, large array of QCDs has also developed. Therefore, it is convenient of QCDs to achieve multiplexing through a microwave feedline like MKIDs. A QCD consists of a high quality factor (Q) microwave superconducting resonators and a single cooper-pair box (SCB). The microwave resonators are fabricated using tantalum (Ta) or niobium (Nb). The SCB is made of aluminum (Al). The ground electrode of the SCB is designed to be an absorber at THz waveband. The absorber is an inductive absorber consisting of orthogonal Al nanowires. Finally, we succeeded in measuring the periodic quantum capacitance signals. However, the responsivity is relatively low due to its weak coupling to the resonators of SCB. In the future, we need to optimize the performance of the detectors. QCDs are a prospect candidate of the next-generation astronomy observation and so on.
Session PS2:
Posters - Multiplexing and Readout I
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Tuesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13102-78
On demand | Presented live 18 June 2024
Show Abstract +
A Radio Frequency System-on-Chip (RFSoC) based readout of microwave frequency resonator based cryogenic sensors is under development at SLAC as an upgrade path of SLAC Microresonator Radio Frequency (SMuRF) electronics with simplified RF hardware, more compact footprint and lower power consumption. The high-speed integrated data converters and digital data path in RFSoC enable direct RF sampling without analog up and down conversion with RF frequency up to 6 GHz. In this paper, a selection of the performance characterization results of direct RF sampling for microwave SQUID multiplexer readout will be summarized and compared with science-driven requirements. The preliminary results demonstrating read out of cryogenic sensors will also be presented here. We anticipate our new RFSoC-based SMuRF system will be the enabling readout for on-going and future experiments in astronomy and cosmology ,which rely on large arrays of cryogenic sensors to achieve their science goals.
13102-79
On demand | Presented live 18 June 2024
Show Abstract +
ASTHROS (Astrophysics Stratospheric Telescope for High Spectral Resolution Observations at Submillimeter-
wavelengths) is a high-altitude balloon mission utilizing an array of sixteen spectrometers to create high spatial
resolution 3D maps of ionized nitrogen gas in galactic and extragalactic star-forming regions. During data
collection, we utilize on-the-fly mapping, where the instrument continuously collects spectra while scanning over
a target area. After a sweep across the target, we take a calibration spectra to correct our science data. These
calibration spectra provide a baseline for how the instrument is operating at a given moment. As we collect
new calibration spectra, we can compare the current calibration with a series of past calibrations to determine
if our system is producing anomalous spectra. Some examples of anomalous spectra are changes in RFI spike
frequency, location, or amplitudes, changes in the overall readout level, and changes in the shape of the spectra.
We compare statistical and data-driven methods for detecting these anomalies and evaluate their performance to
determine the best fit for the ASTHROS readout system. For data-driven methods, we compare th
13102-80
On demand | Presented live 18 June 2024
Show Abstract +
The next-generation mm/sub-mm/far-IR astronomy will in part be enabled by advanced digital signal processing
(DSP) techniques. The Prime-Cam instrument of the Fred Young Submillimeter Telescope (FYST), featuring
the largest array of submillimeter detectors to date, utilizes a novel overlap-channel polyphase synthesis filter
bank (OC-PSB) for the AC biasing of detectors, implemented on a cutting-edge Xilinx Radio Frequency System
on Chip (RFSoC). This design departs from traditional waveform look-up-table(LUT) in memory, allowing real-
time, dynamic signal generation, enhancing usable bandwidth and dynamic range, and enabling microwave kinetic
inductance detector (MKID) tracking for future readout systems. Results show that the OC-PSB upholds critical
performance metrics such as signal-to-noise ratio (SNR) while offering additional benefits such as scalability. This
paper will discuss DSP design, RFSoC implementation, and laboratory performance, demonstrating OC-PSB’s
potential in submillimeter-wave astronomy MKID readout systems.
13102-81
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
Future Cosmic Microwave Background experiments will require denser and larger detector arrays to push forward the instrumentation sensitivity. In this presentation, an innovative compact stacked superconductive interconnect for the readout of an ultra-low temperature detector that is in development at RadiaBeam Technologies will be detailed. This will more than double the current channel density for the CMB focal planes allowing the next generation of multi-frequency CMB receivers (e.g. CMB-S4). The presentation will report on the full concept design of the superconductive interconnect and the project plan for demonstrating feasibility and performance.
13102-82
On demand | Presented live 18 June 2024
Show Abstract +
LiteBIRD is a JAXA led spacecraft mission that has the objective of making a full-sky measurement of the CMB polarization B-modes to constrain the tensor-to-scalar ratio r with a sensitivity of σ(r) of 0.001. Its three telescopes will host a total of 4508 Transition-Edge Sensor bolometers at 100 mK. The signal from the thousands of bolometers will be multiplexed using digital frequency-domain multiplexing (DfMux). In DfMux, each TES in a group of up to 68 is assigned to a frequency channel between 1.5 and 5.5 MHz by an inductor-capacitor (LC) chip, and the multiplexed signal is amplified by a Superconducting Quantum Interference Device (SQUID). Both SQUIDs and LC chips will operate at sub-Kelvin temperatures and be mounted to the detector sub-assembly on the side opposite to the sky, in what we here call the cold readout sub-assembly. Components of the cold readout sub-assembly will need to withstand large mechanical stress during launch and achieve excellent electronic performance to meet the mission’s systematic uncertainty requirements. In this work we present the current status of the design, prototyping and testing of the cold readout sub-assembly components.
13102-83
On demand | Presented live 18 June 2024
Show Abstract +
Arrays of transition-edge sensors (TES) with applications from X-ray to FIR-to-mm astronomy can be read out efficiently using frequency domain multiplexing (FDM) readout with baseband feedback. The calibration of the TES/FDM systems is critical in assessing/improving their performance but the calibration is less straightforward than for TES detectors operated under DC bias.
We have designed and tested a calibration method based on Johnson noise measurements, assuming good knowledge of the LC filter inductance and temperature. With the calibrated Johnson noise source at the input of our readout, we are able to measure both the open-loop and closed-loop behavior of the system. We applied this method to an 88-pixel TES bolometer array under dark conditions. Our new calibration successfully yields useful instrumental properties including TES normal resistances, feedback impedances, IV curves, power plateaus, and dark NEP. Notably, the resulting saturation power does not appear to depend on the resonance frequency, a desirable feature absent in our previous calibrations, suggesting that our noise-based calibration is robust. This calibration method can be applied to future TES arrays.
13102-86
On demand | Presented live 18 June 2024
Show Abstract +
The LSPE/SWIPE instrument is a balloon-borne Stokes polarimeter. The goal of the mission is to measure the polarization of the Cosmic Microwave Background (CMB) at large angular scales, in particular the B-modes, which can provide evidence for the cosmological inflationary model. In this experiment a refractor focuses the light onto two focal planes, populated by 326 Transition Edge Sensors (TES), which are readout through a Frequency Division Multiplexing Electronics (FDM), composed of a cold (1.6 K and 0.3 K) and of a warm (~300 K) section.
In this work we show the operation of a LSPE-SWIPE one channel readout chain, by assembling a board with a representative LC filter bank as a testing multiplexed system, connected to a SQUID. The generation of a comb of tones is performed, together with the processing and analysis of the signal.
13102-87
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
The LSPE balloon experiment utilizes the SWIPE instrument and its ~300 bolometers across three frequencies to measure the large-scale polarization of the CMB. The system incorporates Warm Electronics for signal readout and multiplexing, and Squid Control Units for SQUID interfacing. The primary focus of this work is on the architecture and subsystem testing of the Squid Control Unit (SCU), particularly its interaction with the Warm Electronics.
Session PS3:
Posters - CMD Instruments I
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Tuesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13102-88
On demand | Presented live 18 June 2024
Show Abstract +
The LiteBIRD mission is dedicated to the search for primordial B modes in the Cosmic Microwave Background (CMB) polarization. To achieve unprecedented sensitivity and accuracy in this measurement, the control of instrument systematics is paramount.
In this context, we describe the development of microwave absorbers needed to mitigate the straylight within the telescope tubes of the LiteBIRD Mid- and High-Frequency Telescopes (MHFT).
Leveraging consolidated technologies, a baseline design has been prototyped and characterized in laboratory measurements, consistently demonstrating excellent sub-percent level reflectance across the entire 90-448GHz band of the MHFT under a broad variety of incidence conditions, representative of the actual optical environment predicted for the two telescopes.
Ongoing parallel efforts involve a comprehensive investigation (both through simulations and laboratory measurements) of the requirements to be finalized in order to define the practical implementation of the baseline design. This activity will ultimately ensure the alignment with allocated thermo-mechanical requirements along with the compliance with the desired electromagnetic performance.
13102-89
On demand | Presented live 18 June 2024
Show Abstract +
We present the results from efforts to build a drone-based calibration system designed to provide a high accuracy polarized reference signal needed to characterize the optical response of mm-wave telescopes for mapping the cosmic microwave background radiation. The multi-rotor drone allows the source to reach the far-field of small aperture telescopes, such as CLASS or SO-SATs, at their nominal elevation angle, providing a reference signal while at normal observing conditions. The goal is to achieve calibration accuracy of at least 0.1 degrees on the absolute polarization angle response. Here we present the results obtained during two flight campaigns done at the CLASS site, in Cerro Toco, Chile, intended to test the quality of the on-board metrology system, which uses a combination of GPS and photogrammetry to determine the position and orientation of the source during the flight. These results indicate that the position of the drone is known to within 10 cm and its polarization angle to better than 0.05 degrees, which are in agreement with the technical requirements of the system.
13102-90
On demand | Presented live 18 June 2024
Show Abstract +
The BICEP3 and BICEP Array Polarimeters are small aperture, refracting telescopes at the South Pole designed to measure primordial gravitational wave signatures in the Cosmic Microwave Background (CMB) polarization. Both instruments use orthogonal, co-located detectors that, when differenced, reconstruct the polarized sky signal. As a result, the differential beam response of our detectors becomes one of the primary systematic effects we must control. Mapping the intensity and polarized response of our detectors to the full 360 degree environment at the South Pole and in regions far away from the main beam can give us a better understanding of detector responsivity and could help us place constraints on how sidelobe sensitivity affects our CMB measurements. Extensive, calibration measurements are taken in situ every austral summer for control of instrumental systematics designed to be as close as possible to real observing conditions. I will present analysis and results of such measurements, and outline their impact on our instrumental systematics.
13102-91
CANCELED: The Strip-LSPE instrument: final design and AIV Phase
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
STRIP, together with SWIPE, is one of the two instruments of the LSPE (Large Scale Polarization Explorer) observation program: both measure the microwave polarization of the sky, the first from the ground (from the Izana Observatory – Tenerife, Canary Islands) and the second from a stratospheric balloon. Strip consists of an array of 55 coherent polarimeters coupled to a 1.5 m Cross-Dragon telescope and operates in the two scientific channels, centered at 43 GHz and 95 GHz, based on low-noise HEMT (High Electron Mobility Transistors) amplifiers, cooled to 20 K, capable of directly measuring the Stokes parameters Q and U. The paper provides an overview of the progress of the instrument, with particular attention to the final design and the assembly, integration and verification phase currently underway, exploring the available strategies and results.
13102-92
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
The COSmic Monopole Observer (COSMO) has the target of measuring the largest, yet elusive, spectral distortion of the CMB, the post recombination comptonization (y ~ 2x1e−6), and constrain the ARCADE excess at high frequency. This target is ambitious, since COSMO operates from the ground, in presence of significant atmospheric and instrumental emissions. The instrument is composed of a spinning wedge mirror, providing fast sky dips, feeding a cryogenic Martin Puplett Fourier transform spectrometer, equipped with multi-mode kinetic inductance detectors, covering the two bands 120-180 GHz and 210- 300 GHz. In this contribution, after a general description of the instrument and its implementation in Dome-C (Antarctica), we focus on the optimization of sky coverage, wedge mirror spin frequency and amplitude, and interferogram scan amplitude and speed, which have been optimized to mitigate the effects of atmospheric emission and its slow fluctuations.
13102-93
On demand | Presented live 18 June 2024
Show Abstract +
Future CMB telescopes require large-aperture, anti-reflection coated lenses operating at cryogenic temperatures. The materials involved are generally characterized only at normal incidence angles and rarely at the required temperatures and frequencies. We aim to verify optical designs of next generation CMB telescopes by direct measurement of throughput and imaging quality of individual lenses using a unique cryo-optical test facility.
13102-94
On demand | Presented live 18 June 2024
Show Abstract +
We present the design and validation of a variable temperature cryogenic blackbody source, known as a
cold load, that will be used to characterize detectors to be deployed by CMB-S4, the next-generation ground-
based cosmic microwave background (CMB) experiment. Although cold loads have been used for detector
characterization by previous CMB experiments, this cold load has three novel design features: (1) the ability to
operate from the 1 K stage of a dilution refrigerator (DR), (2) a 3He gas-gap heat switch to reduce cooling time,
and (3) the ability to couple small external optical signals to measure detector optical time constants under low
optical loading. This design was validated using a 150 GHz detector array previously deployed
by the Spider experiment. Thermal tests showed that the cold load can be heated to temperatures required for
characterizing CMB-S4’s detectors without significantly impacting the temperatures of other cryogenic stages
when mounted to the DR’s 1 K stage. Additionally, optical tests demonstrated that external signals can be
coupled to a detector array through the cold load without imparting a significant optical load on the detectors.
13102-95
On demand | Presented live 18 June 2024
Show Abstract +
The Simons Observatory (SO) group of instruments are together pursuing a major step forward in ground-based study of the Cosmic Microwave Background (CMB). The first instrument to record celestial light is the first of two mid-frequency small-aperture telescopes (SATs), SAT MF-1, with over 3,000 dichroic pixels sensitive to two frequency bands centered at 90 and 150 GHz. This instrument began observing in October 2023. In this presentation, we report on some of the initial calibration of the TES bolometer response to electrical and optical signals, including early estimates of the SAT MF-1 sensitivity, and preliminary characterization of possible confounding signals like scan-synchronous pickup. We comment on how these elements pertain to the analysis of systematic errors relating to the ultimate goal of the SO SAT program: the further constraint of the tensor-to-scalar ratio, r, and the possibility of primordial gravitational waves generated in the early universe by a period of inflation.
13102-96
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
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We report on the breadboard model of a polarization modulator unit (PMU) using a sapphire-based achromatic half-wave plate (HWP) for the low-frequency telescope (LFT) of LiteBIRD, the JAXA-led space mission to probe cosmic inflation by observing the polarization of the cosmic microwave background. The PMU is a key component to reduce 1/f noise and the systematic effects between the two orthogonally polarized detectors.
For the HWP, we glued together the surfaces of five 330 mm diameter sapphire plates using hydro catalysis bonding, working as HWP in LFT bands. We also fabricated anti-reflective sub-wavelength structures using ultra-short pulsed laser ablation. For the rotation mechanism, we use a superconducting magnetic bearing and contactless synchronous motor to levitate, and rotate the HWP without any contact. Optical measurements show that fabricated HWP archives broadband transmission and polarization efficiency to obtain a sensitivity close to an ideal HWP. We improved the design of the rotation mechanism and we are investigating the characterization of each component. We will conduct the integration test and show optical, mechanical and thermal performance.
13102-97
On demand | Presented live 18 June 2024
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In this talk, I present the design of the multi-mode antenna arrays of the COSMO experiment and the beam pattern measurements of their fundamental mode, performed at room temperature in an anechoic chamber, compared with simulations.
COSMO is a cryogenic Martin-Puplett Fourier Transform Spectrometer that aims at measuring the isotropic y-type spectral distortion of the Cosmic Microwave Background from Antarctica by performing differential measurements between the sky and an internal, cryogenic reference blackbody.
A spinning wedge mirror performs fast sky-dips at varying elevations while fast, low-noise Kinetic Inductance Detectors scan the interferogram, to reduce the atmospheric contribution.
Two arrays of nine smooth-walled multi-mode feed-horns working in the 120-180 GHz and 210-300 GHz range, respectively, transmit the radiation to the detectors, thus proving a greater throughput and a higher signal-to-noise ratio than traditional single-mode receivers, which allows to increase the instrumental sensitivity without extending the focal plane.
13102-98
On demand | Presented live 18 June 2024
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The Simons Observatory (SO) is a cosmic microwave background experiment located in the Atacama Desert in Chile. SO consists of three small aperture telescopes (SATs) and one large aperture telescope (LAT) with a total of 60,000 detectors in six frequency bands. As an observatory, SO encompasses hundreds of hardware components simultaneously running at different readout rates—all separate from its 60,000 detectors on-sky and their metadata. We outline an overview of commissioning SO’s data acquisition software system for SAT-MF1, as well as insights gained from deployment of data access software for all 4 telescopes, and their impact on data quality investigations for uses further down the pipeline.
13102-99
The Simons Observatory: in-lab optical testing and validation for the first small aperture telescope
On demand | Presented live 18 June 2024
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The Simons Observatory is a ground-based cosmic microwave background survey experiment that consists of three 0.5m Small Aperture Telescopes (SATs) and one 6m Large Aperture Telescope, sited at an elevation of 5200 m in the Atacama Desert in Chile. The SATs will incorporate over 30,000 transition-edge sensor (TES) bolometers in six spectral bands centered between 27GHz and 280GHz.The array of SATs are designed specifically to target the primordial B-mode polarization pattern predicted by a class of inflationary cosmological models. The high sensitivity required to measure primordial B-modes imparts stringent requirements for the characterization of the optical properties of the SATs. We will present a brief overview of the optical design of the SAT as well as the results from in-lab optical tests conducted to assess the detector spectral and polarization response of the first of the Simons Observatory’s Small Aperture Telescopes.
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To distinguish polarized signals from strong non-polarized sky emission, telescopes are equipped with polarimeters. Astronomers need to travel far away to install and test the functionality of instruments on-site. Sky Noise Simulator (SNoS) is intended to simulate strong fluctuating sky emission and weak celestial signals in the lab. This allows the development and testing of instruments without traveling to observatories. SNoS is expected to generated a beam combined of an around 5% linearly polarized signal beam and a non-linearly polarized noise beam as an input for polarimeters, which mimics partially linearly polarized signal from a distant celestial body and non-linearly polarized sky noise. Intensity of noise could be one or two orders of magnitude larger than signal, and intensity of noise is programmed to take a random walk to simulate atmosphere fluctuation. SNoS is developed to test the functionality
of polarimeters and help to improve the sensitivity of polarimeters, which is the limitation to measurements of B-mode polarization of cosmic microwave background (CMB).
Session PS4:
Posters - Imagers and Polarimeters
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Tuesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
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Magnetic field (B-field) is the most controversial factor in molecular clouds for star formation, necessitating further
observations evidence. The Star Formation Group at the Chinese University of Hong Kong is currently engaged in the
construction of ROGer, Hong Kong's inaugural polarimetry. ROGer will be installed on the 12-meter GreenLand Telescope (GLT) and will facilitate the observation of B-field morphology within molecular clouds by utilizing dust thermal emission at 345 GHz. ROGer's polarization module introduces the novel implementation of Martin-Puplett interferometer (MPI) optics, enabling real-time sky noise elimination on the same detector through destructive interference. Two 157-pixel silicon-based aluminum film Microwave Kinetic Inductance Detectors (MKIDs) arrays will be employed to detect the
orthogonal signal from the MPI optics. Here we will present the prototype of our novel MPI polarimetry and optics design.
13102-101
On demand | Presented live 18 June 2024
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This contribution deals with the performance assessment in terms of the radiation features of a C-band Phased Array Feeds (PAF) illuminating the Sardinia Radio Telescope (SRT). For this purpose, we present the study of the coupling of the SRT main reflector, F/D=0.328, with a recently designed PAF especially for radio astronomy applications. In details, firstly we present the study of the far-field combined-pattern of the pixel elements by using two different beamforming algorithms; secondly we characterize the aperture blockage impact due to the secondary reflector of the SRT. Results are shown at three different frequencies within the PAF operative band: at the edges and the center of the bandwidth.
Session PS5:
Posters - New Instruments and Concepts
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Tuesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
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The Africa Millimetre Telescope (AMT) is a project to realize the first millimeter-wave telescope in Namibia desert to participate in the Event Horizon Telescope (EHT) network and make higher-resolution pictures of black holes possible.
We made a preliminary design of the optics to combine the beams of the first light receivers that will enable simultaneous observations of the same area of the sky in four frequency bands. The system is based on the use of dichroics and it has been designed following a geometrical optics approximation to guarantee that all beams will follow the same optical path.
13102-104
On demand | Presented live 18 June 2024
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The Lunar Surface Electromagnetics Experiment at Night (LuSEE-Night) is a project designed to investigate the feasibility of observing the Cosmic Dark Ages using an instrument on the lunar far-side. LuSEE-Night is funded by NASA and the DOE, and is scheduled for launch in December 2025 aboard the Commercial Lunar Payload Services mission CS3.The instrument must function autonomously, and be capable of surviving in the harsh lunar environment. The instrument will be powered by photovoltaic panels on its top, east, and west faces, with a layout designed to optimize the power profile throughout the lunar day. It must be able to survive the long (355 hours) and cold (100K) lunar night, and power the instrument spectrometer, using only a 7kWh battery, due to mass limitations. This presentation describes the design of the LuSEE-Night power systems, and the Concept of Operations (ConOps) for the experiment.
13102-105
On demand | Presented live 18 June 2024
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A novel wideband orthomode transducer (OMT) featuring a folded-arm turnstile junction covering a 2:1 frequency band is employed to achieve an effective structure while meeting the strict OMT requirements for radio astronomy applications. The turnstile junction is designed with two symmetry planes to ensure separation between perpendicular polarizations and the effective management of higher order modes. Within the throat of the turnstile junction, stepped cylinders serve as scattering elements and matching stubs to ensure efficient impedance matching between the quad-ridge circular waveguide at the input and the single-ridge rectangular waveguides at the output. The folded arms play a pivotal role in achieving excellent matching while significantly reducing the overall size. Considering the significance of developing wideband radio astronomy receivers with minimal noise, this design demonstrates a precisely engineered compact OMT, with tuned bends, junctions, and delivers simulated return loss better than 20 dB while maintaining cross-polarization performance well below 65 dB within the specified 20-40 GHz frequency range.
13102-106
CANCELED: Characterizing Thin-film Magnesium Diboride for Superconducting Devices
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
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We describe the characterization of magnesium diboride (MgB2) in the application of superconducting devices. MgB2 has a high transition temperature of 39 K and the level of nonlinear kinetic inductance needed to realize a large current-controlled phase shift for accessibility to frequencies of 0.5 - 3 THz. We demonstrate non-linear kinetic inductance in thin-film MgB2 devices at 4.2 Kelvin with 3-5 um CPW lines and internal quality factors of approximately 14,000. We measure I/I* of 0.22, leading to large current-tunable phase delays in 0-pi/2 radians.
13102-107
On demand | Presented live 18 June 2024
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The Dark-photons & Axion-Like particles Interferometer (DALI) is a proposal for a new generation axion detector designed to probe dark matter in a broad band that ranges from microwaves to mm-wave employing a tunable multilayer Fabry-Pérot interferometer. The apparatus, which is currently in the prototyping phase, imports technology and techniques from radio astronomy. This instrument may also be sensitive to other hypothetical particles, such as the dark photon.
A fixed-plate prototype of a resonator has been manufactured and tested in an optical laboratory setup devised to excite the resonator with a horn antenna and observe its resonant spectral feature from reflectivity measurements. A detailed description of the setup, the post-processing of the data and the observed resonant structure are treated in this work.
13102-108
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
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We present the instrument integration and on-sky commissioning results for Kuntur, the LLAMA 690GHz receiver at the James Clerk Maxwell Telescope (JCMT). The LLAMA band 9 receiver is a state of the art sideband-separating (2SB), dual polarization receiver, built by the Netherlands Research School for Astronomy (NOVA) laboratory at Groningen, Holland for the Large Latin American Millimeter Array (LLAMA). In a joint collaboration with LLAMA, ASIAA and the Greenland Telescope, it has come on loan to JCMT for on-sky commissioning and future VLBI observing tests. The results reveal the potential for single dish observing science at 690GHz with JCMT on Maunakea and provides a pointer to future 690GHz science for the GLT and LLAMA.
13102-109
On demand | Presented live 18 June 2024
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The Probe far-Infrared Mission for Astrophysics (PRIMA) is a proposed space observatory which will use arrays of thousands of kinetic inductance detectors (KIDs) to perform low- and moderate-resolution spectroscopy throughout the far-infrared. The detectors must have noise equivalent powers (NEPs) at or below 0.1 aW/rt(Hz) to be subdominant to noise from sky backgrounds and thermal noise from PRIMA's cryogenically cooled primary mirror. Using a Radio Frequency System on a Chip for multitone readout, we measure the NEPs of detectors on a flight-like array designed to observe at a wavelength of 210 microns. We find that 92% of the KIDs measured have an NEP below 0.1 aW/rt(Hz) at a noise frequency of 10 Hz.
13102-192
On demand | Presented live 18 June 2024
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We present the Planetary Origins and Evolution Multispectral Monochrometer (POEMM), a 1.8 meter balloon-based telescope and far-infrared spectrometer proposed to NASA’s Pioneer program. The POEMM design utilizes direct-detection VIPA and MKID technologies that is optimized to probe the evolution of circumstellar disks into planetary systems. POEMM will velocity resolve the lowest two rotational transitions of HD, selected low-lying rotational transitions of water vapor, and the 63 um [OI] line which will tomographically reveal the disk mass, the thermochemistry of water vapor and the disk energy balance as a function of radial distance from the central star at sub-AU precision. These critical diagnostic lines are not detectable from the ground, so that the science yield is both compelling and unique. POEMM’s low-resolution grating spectrometer enables measurement of the virtually unexplored solid-state water ice features at 43 and 63 um that reveal the ice mass, and when combined with the line tomography measures the snow line in the systems. The POEMM team involves people from several partner institutions, led by Cornell University.
13102-188
On demand | Presented live 18 June 2024
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The North West University’s Nooitgedacht Observatory has installed four antennas for the purpose of radio interferometry observations in C-band. This paper describes an improve low-noise block downconverter for spectral and continuum measurements, using a single coaxial port for IF transport, local reference distribution, DC biasing and noise injection control. The science cases for this receiver system are; (1) Bright 6.7 GHz methanol (CH3OH) maser monitoring observation (in spectral mode), (2) monitoring observations of bright radio galaxies like quasars, (3) and solar observations. We present details on the design of a signal multiplexing system, injection-locking mechanism, and noise-injection system. The design features an average system temperature of 490K, with an average passband gain of 48.8 dB, and 460 MHz input bandwidth and a calibration noise source with a noise temperature of 20000K.
Session PS6:
Posters - Detectors II
19 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Wednesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13102-110
19 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
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The Terahertz Intensity Mapper (TIM) aims to investigate star formation trends in dust-obscured galaxies during the peak of cosmic star formation by measuring the redshifted 157.7 μm line of singly ionized carbon ([CII]). TIM utilizes two long-slit grating spectrometers, each equipped with an array of horn-coupled aluminum kinetic inductance detectors (KIDs). Designs aimed for a 50-micron uniform boss height in our hornblock arrays, but measurements show non-uniformity in these heights. Sonnet simulations, considering different boss heights and IDC parameters, reveal insights into the impact of various boss heights on the resonance frequencies of the KIDs. Anticipating these frequencies lets us strategically adjust detector designs for optimal performance, compensating for non-ideal boss heights on the array. We will present the study's findings and implications for optimizing KID performance.
13102-111
CANCELED: Addressing persistence in ESO near-infrared detectors
19 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
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Persistence is the effect whereby a remnant signal from a previous exposure is imprinted on a subsequent image. This effect has long been known to affect near-infrared (NIR) detectors and, if severe, the persistence artefacts can last many hours and can severely affect subsequent observations.
To date, most strategies only attempt to prevent persistence by strongly limiting the maximum flux to which a detector is exposed. However, this simple method of persistence mitigation severely limits the available dynamic range of any instrument, is insufficient when detectors show persistence even at very low levels of flux and, in the case of the ELT, susceptibility to persistence will be amplified. Using a detailed analysis of persistence behaviour in each new NIR detector, as done by the ESO detector laboratory, we have devised an algorithm to create a predictive map of persistence for any science exposure. We use the past exposure history of each source detected in the frame and map the accumulation and subsequent decay of each persistence trap. Our goal is to implement this into ESO/Paranal operations and automatically provide persistence correction frames for its NIR instruments.
13102-112
On demand | Presented live 19 June 2024
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A large cryogenic facility has been developed to simulate the impact of cosmic rays on cryogenic detectors and part of focal planes. Particles such as protons or ions of various energies are produced with either an internal radioactive source or by coupling our facility DRACuLA (Detector irRAdiation Cryogenic faciLity for Astrophysics) to a particle accelerator. This system has been operated in front of the ALTO particle accelerator during a May 2024 test campaign dedicated to the study of these impacts on TESs (Transition Edge Sensor) operated at sub-K temperatures.
13102-114
On demand | Presented live 19 June 2024
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TIM, the Terahertz Intensity Mapper, is a NASA far-infrared balloon mission designed to perform [CII] intensity mapping across the peak of cosmic star formation. TIM will fly two grating spectrometers that together cover the 240 to 420 um wavelength range at an R~250. Each spectrometer will require large format arrays (4x~900 detectors) of dual-polarization sensitive detectors, which are photon noise limited at 100 fW of loading. We will present the optical performance of an kilo-pixel array fully-aluminum lumped-element kinetic-inductance detector (KID) for TIM’s long wavelength spectrometer. We demonstrate a >90% fabrication yield, which can be reliably achieved across multiple arrays, and resonator quality factors matching the design. Operating at 250 mK, as expected for flight, we demonstrate that >70% of the detectors achieve photon noise limited performance at the expected in-flight optical loading of 200 fW with a white noise spectrum down to 1 Hz.
13102-116
On demand | Presented live 19 June 2024
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We present a characterization of the mapping from spatial position to resonant frequency for a kilopixel kinetic inductance detector (KID) subarrays developed for the Probe far-Infrared Mission for Astrophysics (PRIMA). This work targets the longest wavelength bands of PRIMA’s FIRESS spectrometer, which in total spans 24 to 235 microns. Light emitting diodes arrayed to match repeating unit cells of 16 KIDs first discriminate among unit cells. Within each unit cell, frequencies are widely spaced, so positions are discriminated by simulated and theoretical predictions based on KID geometries. With this mapping, we analyze board features to improve the accuracy of modeling PRIMA KIDs and inform future fabrication runs.
13102-117
On demand | Presented live 19 June 2024
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Prime-Cam, a first-generation science instrument for the Atacama-based Fred Young Submillimeter Telescope, is being built by the CCAT Collaboration to observe at millimeter and submillimeter wavelengths using kinetic inductance detectors (KIDs). Prime-Cam’s 280 GHz instrument module will deploy with two aluminum-based arrays and one titanium nitride-based array of KIDs, totaling ~10,000 detectors, all of which are currently undergoing testing. One complication of fielding large arrays of KIDs under dynamic loading conditions is tuning the detector tone powers to maximize signal-to-noise while avoiding bifurcation due to the nonlinear kinetic inductance. For aluminum-based KIDs, this is further complicated by the existence of additional nonlinear effects which couple tone power to resonator quality factors and resonant frequencies. We present a focused look at the competing nonlinearities seen in Prime-Cam’s 280 GHz aluminum KIDs, with a particular emphasis on the resulting distortions to the resonator line shape and how these impact detector parameter estimation.
13102-118
On demand | Presented live 19 June 2024
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High-resolution terahertz observation is needed to understand galaxy forming process and high-z universe. We propose Terahertz Intensity Interferometry (TII), which aims for aperture synthesis by measuring delay time from photon bunching. 1.5 THz photon counting detectors were designed for the first TII observation from Antarctica. The detectors adopt antenna-coupled pair-breaking SIS junction, which detects photons by impedance matching and is expected to be a fast response. We will discuss the design and performance of the detectors.
13102-119
On demand | Presented live 19 June 2024
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SCUBA-2 is still a world leading wide field submillimeter camera on the JCMT, producing a wide range of science results, including a unique series of large survey programs. The SCUBA-2 instrument and TES detector arrays have been in constant operation for over a decade at JCMT. In this paper we review the performance of (a) the NIST fabricated TES wafers and 2D Time Domain SQUID MUX over a 10-year range and numerous thermal cycles, (b) the cryogenics, which consists of the original liquid cryogen-free dilution fridge and three Cryomech pulse tubes and (c) the cryostat, including the cold shutter mechanism.
13102-185
On demand | Presented live 19 June 2024
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The goal of the SPID/IQSENS project is the development of SNSPD for specific applications, requiring wavelength sensitivity longer than the communication window of 1550 nm. In this paper, the status of the research and development of SNSPD within the SPID/IQSENS is presented. n-going to satisfy the requirements.
Session PS7:
Posters - Optics and Components I
19 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Wednesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13102-120
On demand | Presented live 19 June 2024
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Wide-field-of-view millimeter-wave telescopes have been developed for astronomical observations, such as cosmic microwave background (CMB) polarimetry. These telescopes often employee phase-insensitive detectors that are fabricated with the on-chip feed antennas. A holographic field-retrieval method is useful for near-field antenna measurements of such telescopes. Among several variations of the methods, we present the one using the phase shifting of the reference waves, which do not require a fine frequency sweeping. This method aims at application to the ground testing of the LiteBIRD Low-Frequency Telescope (LFT) antenna, which observes the CMB and foreground radiations at 34 - 161 GHz. In our experiments conducted with a 1/4-scaled LFT antenna, the new method indicated an accuracy of -56 dB levels, which is required for the sidelobe levels of the LFT.
13102-122
19 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
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The Terahertz Intensity Mapper (TIM) will use far-infrared line intensity mapping to construct a 4-dimensional dataset probing cosmic evolution spanning five billion years. TIM's optical system, featuring a Cassegrain telescope, an Offner relay, and two Czerny-Turner spectrometers, covers distinct short-wave (240-317 μm) and long-wave (317-420 μm) bands. We will present TIM's cold optics designs, assembled systems, and measurements using a coordinate measurement machine (CMM), comparing results to expected design tolerances. This work contributes to advancing observational capabilities for studying cosmic evolution in the far-infrared spectrum.
13102-123
19 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
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Silicon optics with broadband antireflection treatment would benefit many astronomical applications at millimeter and sub-millimeter wavelengths requiring broad spectral coverage. By etching sub-wavelength features inside silicon wafers it is possible to locally vary silicon’s effective refractive index and create antireflective structures or gradient index lenses. We present our results to date, which include the design, simulation, fabrication and measurement of 4-layer antireflective structures covering 100-400 GHz and a flat gradient index lens with 3-layer antireflective structures with comparable bandwidth.
13102-124
19 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
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LiteBIRD is a space telescope designed to test inflationary theories by observing the polarization of the cosmic microwave background (CMB). The Low-Frequency Telescope (LFT) on board LiteBIRD should be surrounded by millimeter-wave absorbers to mitigate stray light. Because the LFT requires far-sidelobe knowledge at the -56 dB level, not only specular reflection but also diffuse reflection from the absorbers must exhibit low levels.
We have developed a method for a near-field reflection measurements of absorbers, which can derive a two-dimensional reflection pattern of absorbers. We have measured a new ultralight absorber for two polarizations with a 30 degree angle of incidence in the frequency range between 70 GHz and 110 GHz. Measurements show that this has a lower reflectance than the industry standard Eccosorb AN-72.
13102-125
On demand | Presented live 19 June 2024
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Front-end polarization modulation enables improved polarization measurement stability by modulating the targeted signal above the low-frequency 1/f drifts associated with atmospheric and instrumental thermal instabilities. In this work, we present the design and characterization of a new 60-cm diameter Reflective Half-Wave Plate (RHWP) polarization modulator. This RHWP consists of an array of parallel wires (diameter 50 µm, 175 µm pitch) placed at a fixed distance in front of a mirror. In-lab tests confirmed the flatness and alignment of the wire array and mirror and the mechanical stability of the system, and the array met the requirements needed for cosmological observation. The RHWP will be the telescope's first optical element, which mitigates instrument polarization from other components along the optical path. It will be installed in the 90 GHz band of the Cosmology Large Angular Scale Surveyor.
13102-126
On demand | Presented live 19 June 2024
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Artificial dielectric metamaterial elements fabricated using capacitive grids with dielectric spacer thickness are analyzed using Equivalent Ideal transmission line models having a single effective impedance and phase length. These ideal transmission line models are compared to the full-wave EM model for such capacitive grid metamaterial elements to demonstrate that such capacitive grid metamaterial elements can be designed to have arbitrarily high values of index of refraction in the THz/Millimeter-Wave bands. The fabrication process and the application of such a capacitive grid metamaterial in developing a stepped-impedance quasi-optic filter for CMB telescope applications is discussed.
13102-127
On demand | Presented live 19 June 2024
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Simultaneous multi-band observations, specifically in the millimeter to Terahertz frequency range, are increasingly gaining prominence in radio astronomy. Multi-band capabilities enhance the throughput of radio telescopes and provide valuable astronomical information, particularly for time domain observations. To facilitate successful simultaneous multi-band observations, a low-loss diplexing scheme, to effectively separate the beam from the telescopes to feed the various receivers, is indispensable. This paper presents our innovative optical diplexer design, grounded in the strategic layering of dielectric material.
13102-128
On demand | Presented live 19 June 2024
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We have successfully aligned the DESHIMA 2.0 optics at ASTE, as part of the DESHIMA 2.0 commissioning and science verification campaign, using a modified Dragonian dual reflector attached to a mechanical hexapod and a fast sky-position chopper. DESHIMA 2.0 is an Integrated Superconducting Spectrometer (ISS), with science cases ranging from spectroscopic studies of high-redshift dusty, star-forming galaxies, to galaxy cluster science using the Sunyaev-Zel’dovich effect.
We align the instrument by scanning the instrument beam across the entrance aperture of the sky-position chopper and observing the contrast between the cold sky and warm chopper interior. Sky observations verify the alignment of our instrument, proving the veracity of the described technique.
The power of the alignment procedure lies in the fact that it can be executed remotely, eliminating the need for physical presence at the telescope during aligning. The optical components required in addition to the present optics is minimal.
13102-170
On demand | Presented live 19 June 2024
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Due to high dynamic range and ease of use, continuous wave terahertz spectroscopy is an increasingly popular method for optical characterization of components used in cosmic microwave background (CMB) experiments. In this work, we describe an optical testbed that enables simultaneous measurements of transmission and reflection properties of various radiation absorbing dielectric materials, essential components in the reduction of undesired optical loading. To demonstrate the performance of the testbed, we have measured the reflection response of five absorbers commonly used for such applications: TKRAM, carbon- and iron-loaded Stycast, HR10, AN72, and an in-house 3D printed absorber across a frequency range of 100 to 500 GHz, for both S- and P-polarization, with incident angles varying from 15 to 45 degrees. We present results on both the specular and scattered reflection response of these absorbers.
Session PS8:
Posters - CMD Instruments II
19 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Wednesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13102-130
On demand | Presented live 19 June 2024
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LiteBIRD is a CMB polarization experiment satellite that targets the measurement of primordial B-modes to test cosmic inflation. The LiteBIRD Low-Frequency Telescope employs a polarization modulator unit (PMU) to mitigate the differential systematic effects. The current PMU design employs three cryogenic holder mechanisms, which are actuated by a cryogenic stepping motor. Minimizing the heat dissipation is the key to achieving the development goals of the PMU. We prepared a custom stepping motor using high-purity copper wire and tested its functionality at the temperature below 10 K. The estimated temperature of the high-purity copper wire is about 10 K based on the thermometer attached on the outer chassis of the stepping motor. We estimated the total heat dissipation from the change of its temperature when the motor operated without any mechanical load. We identified that the dominant contributions of the heat dissipation are hysteresis loss and frictional loss at the bearing, which are proportional to the rotation frequency. In this presentation, we report on the specifications and thermal characteristics of the cryogenic stepping motor and holder mechanism.
13102-134
On demand | Presented live 19 June 2024
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Presently, experiments aimed at mapping the cosmic microwave background (CMB) and further constraining the energy scale of cosmic inflation require extensive studies of potential systematic effects. Typically operating in the 40-400 GHz frequency range, these experiments are particularly sensitive to optical systematics of various form. Near-field vector beam mapping, or holography, is now employed in a variety of CMB-focused experimental efforts due to the technique's ability to provide full details of electromagnetic field propagation through complex systems. In this proceeding, we describe the development of a millimeter-wave system for phase-sensitive beam mapping with the goal of characterizing telescopes and telescope components for CMB experiments. We discuss the testing of a scanning mechanism based on a 6-axis robot arm, the software we have written for interacting with it, the readout architecture and the overall validation of the system through various testing procedures.
13102-135
On demand | Presented live 19 June 2024
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We present the development of alumina infrared absorptive filters for millimeter-wave astrophysics. We focus on three frequency bands near 30, 125, and 250 GHz, which are typically used by ground-based cosmic microwave background instruments. We used laser ablation to pattern the filter surfaces with sub-wavelength structures (SWS) that serve as an anti-reflection coating (ARC). We report on the volume ablation rate, SWS uniformity, transmittance and polarimetric performances, and prospects to scale the process to large area samples.
13102-136
On demand | Presented live 19 June 2024
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The LiteBIRD mission is a next generation CMB space mission which aims to detect the primordial gravitational waves with a sensitivity of δ r < 0.001. The polarization modulator unit (PMU) represents a critical and powerful component
to avoid 1/ f noise contribution and mitigate differential systematic uncertainties by the two orthogonal polarization sensitive sensors on both Mid- and High- Frequency Telescopes.
Each PMU is based on a continuously transmissive rotating half-wave plate (HWP) held by a superconducting magnetic bearing in the 5K environment. The dynamical behaviour of the system during the rotation has to be monitored because it can introduce systematics during the astrophysical measurement.
In this contribution, we will present the development of capacitive sensors used to monitor the spinning rotor. A set of these sensors allow to monitor the levitation height and the wobbling of the rotor with an accuracy < 1 arcmin. A thermometer can be also coupled with one of this capacitor which is used both to bias and to read-out its temperature.
13102-137
On demand | Presented live 19 June 2024
Show Abstract +
COSMO (COSmic Monopole Observer) is an experiment aimed at the searching for spectral distortions in the CMB (Cosmic Microwave Background) between 120 and 300 GHz. COSMO will be operated from Concordia Station on the Antarctic plateau. The experiment is based on a cryogenic Martin-Puplett interferometer whose superconductive detectors are KIDs (Kinetic Inductance Detectors). The interferometer produces interferograms proportional to the difference between the sky and an internal reference black body. The sky signal has a fast modulation to compensate for the atmospheric fluctuations. A key requirement of the readout is an ultra-fast rate to track the signal modulation and also for detector diagnostic. The readout architecture is based on an IQ transceiver generating a comb of test tones tuned to each detector. We developed a modular readout based on commercial components for reliability and fast prototyping. We were able to reach and sustain a readout rate higher than 60 kHz for 18 detectors. In this contribution a general description of the architecture, together with the main performances in terms of amplitude and phase noise are given.
Show Abstract +
Prime-Cam is a modular first-generation science instrument for the CCAT Observatory's six meter aperture Fred Young Submillimeter Telescope (FYST). FYST’s crossed Dragone design and unique site at 5600 m in Chile’s Atacama Desert will allow for mapping speeds over ten times greater than current submillimeter experiments. Housing seven independent instrument modules in its 1.8 meter diameter cryostat, Prime-Cam will combine broadband polarization-sensitive modules and spectrometer modules observing in several frequency windows between 210 and 850 GHz to study a wide range of astrophysical questions. To cover this range of frequencies and observation modes, each module contains a set of cold reimaging optics optimized for the goals of that module. These optical setups include several filters, three or four anti-reflection-coated silicon lenses, and a Lyot stop to control the field of view and illumination of the primary mirror, satisfy a series of mechanical constraints, and maximize optical performance within each passband. We summarize the design considerations and trade-offs for the optics in these modules and provide a status update on the fabrication of the Prime-Cam receiver.
13102-139
19 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
The imporvement in drones performances is driving their usage for the characterization of radio telescopes: properties such as the polarization angle, beam shape and gain need are becoming more and more critical to obtain clean science results, especialy for CMB experiments; a source carried by a drone may help in assessing these properties. Large telescopes restrict the usage of a drone in their near field. We demonstrate that these near-field measurements, in combination with far field point source observations, can be used to infer the mirror misalignments and deformations due to thermal or gravitational stress. The proposed method does not need the phase information, making it a powerful tool for telescope equipped with bolometric detectors, for which the phase is not available.
13102-140
On demand | Presented live 19 June 2024
Show Abstract +
The Simons Observatory is a new ground-based cosmic microwave background experiment located in Chile’s Atacama Desert. During its survey, the observatory’s telescopes will map the sky with unprecedented precision with the aims of constraining cosmic inflation models and cosmological parameters, and mapping large-scale structure. This presentation will discuss studies of detector yield and readout noise from the commissioning of the readout system for the Simons Observatory large aperture telescope. This novel readout system was designed to read out more than 60,000 transition-edge sensor bolometers across the observatory's telescopes using microwave SQUID multiplexing technology.
Show Abstract +
PROTOCALC (PROTOtype CALibrator for Cosmology) is an artificial calibrator for cosmological experiments, with a focus on mm-wave telescopes. PROTOCALC was designed to achieve a polarization angle accuracy better than 0.1°, which is a factor of 3 improvement compared to celestial sources like TAU-A. Preliminary measurements gives an accuracy of 0.04° in roll and a clear signal seen by the telescope.
13102-131
On demand | Presented live 19 June 2024
Show Abstract +
Cosmic microwave background telescopes such as the Atacama Cosmology Telescope (ACT) and Simons Observatory (SO) observe the CMB at multiple frequencies in order to separate the CMB signal from other foreground components in the sky. Dramatic increases in sensitivity for these experiments mean that the limiting factor for foreground separation has become our ability to measure the detector bandpasses. We simulate and analyze multiple frequency-dependent systematic effects of a Fourier-transform spectrometer (FTS) and its output coupling optics and evaluate their effects on the final measured Advanced ACTPol passbands. We then outline the steps going forward which will mitigate these systematics and improve future FTS measurements of next generation experiments in order to take full advantage of their rich upcoming datasets.
13102-132
On demand | Presented live 19 June 2024
Show Abstract +
B-Mode Polarization of the Cosmic Microwave Background (CMB) provides a probe into the structure of the early universe. The small magnitude of this polarization requires modern CMB experiments to rigorously remove unwanted noise sources. Many of these noise sources manifest in detectors as so-called 1/f noise. To remove this noise, a standard experimental technique is to implement a rotating half-wave plate, which modulates the CMB polarization above the low frequency cutoff. We present the status, control software, and initial characterization of two continuously rotating “cryogenic” half-wave plates (CHWP), the first integrated into the POLARBEAR-2B (PB2b) receiver of the Simons Array and the second integrated into the Small Aperture Telescope (SAT-MF1) receiver of the Simons Observatory. In particular, we highlight recent commissioning data taken at the Chilean site.
13102-191
On demand | Presented live 19 June 2024
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In this paper, we present the European Low Frequency Survey (ELFS), a project that will enable foregrounds-free measurements of primordial B-mode polarization to a level 0.001 by measuring the Galactic and extra Galactic emissions in the 5–120 GHz frequency window. Indeed, the main difficulty in measuring the B-mode polarization comes from the fact that many other processes in the Universe also emit polarized microwaves, which obscure the faint CMB signal. The first stage of this project is being carried out in synergy with the Simons Array (SA) collaboration, installing a 5.5–11 GHz coherent receiver at the focus of one of the three 3.5 m SA telescopes in Atacama, Chile (“ELFS on SA”), followed by the installation of the QUIJOTE-MFI2 in the 10-20 GHz range. The receiver is equipped with a fully digital back-end that will provide a frequency resolution of 1 MHz across the band, allowing us to clean the scientific signal from unwanted radio frequency interference, particularly from low-Earth orbit satellite mega constellations. This paper reviews the scientific motivation for ELFS and its instrumental characteristics, and provides an update on the development of ELFS on SA.
Session PS9:
Posters - Coherent Receiver
19 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Wednesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
Show Abstract +
All sub-millimeter balloons and ground-based telescopes could benefit from a compact, re-configurable, high gain, programmable amplifier module to use in their receivers. Using a five-stage Intermediate Frequency (IF) Low Noise Amplifier (LNA) added to a readout chain using commercial off-the-shelf components, the amplifier module yields 70 dB of gain up to 5 GHz with 31.75 dB of programmable attenuation with relatively linear gain flatness of ± 1dB. This amplifier module has a unique form factor that combines the entire amplifier chain and bias system all in one module, saving space and weight on the system.
13102-143
Design and analysis of 230/460 GHz dual-color all-NbN superconductor-insulator-superconductor mixers
19 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
In this work, the 230/460 GHz dual-color all-NbN superconductor-insulator-superconductor mixers were designed and analyzed. The NbN/AlN/NbN tunnel junctions (with an energy gap of 5.6 meV) and NbN/MgO/NbN tuning circuits were utilized. Full-height waveguides and bow-tie waveguide probes were adopted. The dual-color mixers are still being designed. Current results show that in the frequency range of 200-260 GHz, the return loss of the waveguide-to-microstrip transition circuit is less than 6 dB, and even less than 11 dB at 230 GHz. The embedding impedance is about 21 ohms with good frequency independence. The dual-color mixer has higher observation efficiency and better anti-interference ability compared to the single-color one. The proposed design will provide technical support for the recovery and upgrade of the 230/460 GHz heterodyne receiver for the Leighton Chajnantor Telescope (LCT).
13102-144
On demand | Presented live 19 June 2024
Show Abstract +
A two-stage cryogenic low noise amplifier (LNA) with a usable frequency range of 0.5 to 8 GHz (L to C-band) at 4 Kelvin. The amplifier was designed to have high linearity and dynamic range with an acceptable noise temperature. The low noise amplifier (LNA) uses two Diramics Indium Phosphide (InP) pHEMTs and other commercial surface mount (SMT) components. The use of SMT components minimizes the number of bond wires needed to assemble the amplifier increasing its manufacturability. The LNA has a gain of 25 dB ± 1dB and a power consumption at 4 Kelvin ranging from 3.4 to 8 mW.
13102-145
On demand | Presented live 19 June 2024
Show Abstract +
In pursuit of advancing large array receiver capabilities and enhancing the 16-element Heterodyne Array Receiver Program (HARP) instrument on the James Clerk Maxwell Telescope (JCMT), we have successfully fabricated 230GHz finline SIS mixers. These mixers are critical for assessing the potential and prospective for the HARP instrument's upgrade. This mixer design is expected to operate from about 160-260,GHz, and the mixer chips' I-V curves have been characterized, showing promising results with a quality factor Rsg/Rn exceeding 9.3. Evaluation of the double-sideband (DSB) receiver noise temperature Trx is currently underway. Once successfully characterised, our immediate aim is to scale the mixer to operate at HARP's frequency range near 345 GHz to achieve similar broad RF bandwidth performance. Ongoing simulations are currently being conducted for the design of the 345 GHz finline mixer. This work marks a crucial step toward toward enhancing HARP receiver performance with better sensitivity and wider IF bandwidth, enabling higher-frequency observations, and expanding the scientific potential of the JCMT and its collaborative partners.
13102-147
On demand | Presented live 19 June 2024
Show Abstract +
Recent years, the development of the 86 GHz receiver systems at the East Asia VLBI Network (EAVN) has started. Currently, only three KVN antennas provide 86 GHz VLBI capability in the member stations of EAVN. The participation of VERA in the 86 GHz VLBI observations will boost resolution, sensitivity, and dynamic range.
Therefore, we are developing a new 86 GHz low noise receiver system to be installed at VERA Mizusawa and Ishigaki stations. We are considering a cooled circular polarization receiver covering a wide frequency range of 67-116 GHz with a capability of cooling even HEMT amplifiers. In this poster, we will particularly discuss the development progress of the 2SB receiver and the design status of the cooling Dewar.
13102-148
On demand | Presented live 19 June 2024
Show Abstract +
We describe the preliminary development and performance of the Kinetic Inductance Traveling-Wave Parametric Amplifier (KI-TWPA) for (sub)millimeter wavelength technology. Findings will show preliminary simulations and lab results pertaining to the gain, bandwidth and noise of a 100GHz KI-TWPA device. The target of this development is the integration of the KI-TWPA in a millimeter wave receiver for on-sky astronomical validation. We show response measurements at the millimeter-wave of our device and compare experimental data to simulations for our superconducting amplifier.
Show Abstract +
The Millimetron Space Observatory is based on a 10 m diameter deployable telescope that will be launched to Lagrange point L2. Millimetron will be will be equipped with the cryogenically cooled instruments for a Space-Earth Very Large Baseline Interferometry (S-E VLBI). It will be a heterodyne multichannel receiver including 7mm, 3mm, 1.3mm and 0.8mm channel. Two low frequency channels will be based on HEMT amplifiers, while for the high frequencies superconductor-insulator-superconductor (SIS) receivers will be utilized. The VLBI instrument will have a multi frequency capability allowing simultaneous observation using several channels. This mode has a high potential for improving of black hole event horizon observations due to phase transferring capabilities. The multi-frequency observation will be provided by a signal split in the input optics and by back-end capabilities. The onboard facilities will allow the parallel operation of all four VLBI receivers.
13102-150
Broadband tuneable travelling wave parametric multiplier based on high-gap superconducting thin film
On demand | Presented live 19 June 2024
Show Abstract +
The superconducting quantum parametric amplifier (SPA) technology, known for its adaptability, can serve as frequency multipliers by leveraging the low-noise, low-loss superconducting nonlinear transmission line. Its applications range from 'pumping' SIS mixers to driving high-frequency SPAs, offering a high-purity signal source at the cryogenic stage. This paper introduces a travelling-wave parametric multiplier (TWPaM) design, utilizing non-linear wave-mixing for operation of broadband tunable tripler with a high conversion efficiency. We use a niobium titanium nitride (NbTiN) SPA as example to showcase the methodology. Theoretical models and phase-matching techniques to achieve broadband operation will be discussed. Preliminary results of a TWPaM operating at the Ka-band are expected to be presented during the meeting.
Show Abstract +
The ALMA2030 Wideband Sensitivity Upgrade (WSU) is the top priority initiative for the ALMA Development Roadmap. The WSU will initially double, and eventually quadruple, ALMA’s system instantaneous bandwidth and deliver improved sensitivity by upgrading the receivers, digital electronics, and correlator. The WSU will afford significant improvements for every future ALMA observation.The improved sensitivity and spectral tuning grasp will open new avenues of exploration, increase sample sizes, and enable more efficient observations. The WSU is now well underway with key subsystem under development, including new receivers, digitizers, data transmission system and correlator. In parallel, the observatory is advancing the detailed planning towards implementation through a careful project management and systems engineering approach, based on an integrated Conceptual System Design which outlines the hardware, computing and science operations aspects of the upgrade. The substantial gains in the observing efficiency enabled by the WSU will further enhance ALMA as the world leading facility for millimeter/submillimeter astronomy.
Session PS10:
Posters - Multiplexing and Readout II
20 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Thursday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13102-84
On demand | Presented live 20 June 2024
Show Abstract +
The IAC Electronics Department has developed a high-performance embedded Data Acquisition System (eDAS) to perform the readout of an array of microwave kinetic inductance detectors (MKIDs) and to carry out hardware-based digital signal processing in real time. The eDAS has been developed using the Zynq UltraScale+ RFSoC ZCU111 Evaluation Kit and PYNQ software framework. The ultimate goal is to be able to detect changes in the amplitude and phase of the MKID’s signal when a photon arrives at the detector, in order to observe a single photon signature. We have been able to identify the resonant frequency of individual pixels in total darkness.
13102-151
20 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
This work discusses the Kinetic inductance Parametric UP-converter (KPUP) as a Frequency
Domain Multiplexing (FDM) readout device for sensors commonly used in the astronomical
community, such as the Transition Edge Sensor (TES), Metallic Magnetic Calorimeter (MMC),
and Superconducting Nanowire Single Photon Detector (SNSPD). The KPUP converts small
current signals into sidebands on a microwave carrier tone using a superconducting resonator
with nonlinear kinetic inductance. Devices were designed based on half-wavelength resonators
with an inverted microstrip geometry and amorphous silicon dielectric layer. A DC bias is used
to tune the resonator frequency and sensitivity to an additional sensor signal. This work will
detail current response of KPUPs made out of NbTiN, NbN, and MoN and noise measurements of the NbN and NbTiN KPUPs. The KPUP is a particularly interesting FDM technique for applications for which a monotonic
current response is advantageous.
13102-152
On demand | Presented live 20 June 2024
Show Abstract +
The Fred Young Submillimeter Telescope (FYST), on Cerro Chajnantor in the Atacama desert of Chile, will
conduct wide-field and small deep-field surveys of the sky with more than 100,000 detectors on the Prime-Cam
instrument. Kinetic inductance detectors (KIDs) were chosen as the primary sensor technology for their high
density focal plane packing. Additionally, they benefit from low cost, ease of fabrication, and simplified cryogenic
readout, which are all beneficial for successful deployment at scale. The cryogenic multiplexing complexity is
pulled out of the cryostat and is instead pushed into the digital signal processing of the room temperature
electronics. Using the Xilinx Radio Frequency System on a Chip (RFSoC), a highly multiplexed KID readout
was developed for the first light Prime-Cam and commissioning Mod-Cam instruments. We report on the
performance of the RFSoC-based readout with multiple detector arrays in various cryogenic setups. Specifically
we demonstrate detector noise limited performance of the RFSoC-based readout under the expected optical
loading conditions.
13102-154
On demand | Presented live 20 June 2024
Show Abstract +
CMB-S4 is the next generation, ground-based, cosmic microwave background (CMB) observatory. It is designed
to explore the scientific potential contained in the CMB temperature and polarization anisotropies. The goal of
CMB-S4 is to observe the mm sky with about 500,000 transition edge sensors (TES). These cryogenic detectors
are read out using time division multiplexing (TDM). Two stages of superconducting quantum interference
devices (SQUIDs) are used at cryogenic temperatures for multiplexing and amplifying the signals coming from
the TESs. This imposes stringent noise requirements to the electronics for readout. In this paper, we discuss
the developments and the first tests of an analog front-end differential electronics daughter board. The board
is based on an SiGe application-specific integrated circuit, the AwaXe v3, developed for the readout
of ATHENA’s X-IFU instrument. It provides low-noise amplification (LNA) after the cryogenic multiplexer
and supplies the low noise current bias for the two SQUID stages and TESs. This front-end electronics is
expected to improve the noise performances of the CMB-S4 readout chain and help moving towards a differential
and compact design.
Session PS11:
Posters - Spectrometers I
20 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Thursday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13102-155
20 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
To study the spatial variations of the cosmic microwave background (CMB) across large spatial scales as well as galaxy clusters using the Sunyaev-Zeldovich (SZ) effect, a large imaging spectrometer with low spectral resolution is needed. To this end, we designed, fabricated and measured a 135 GHz to 270 GHz low spectral resolution (R=30) filter-bank for a ground based on-chip superconducting imaging spectrometer. We adopt the on-chip filter-bank technology from DESHIMA 2.0 and redesign the filters to achieve the targeted spectral resolution R = 30 and a > 80% efficiency over the whole frequency band. To achieve such high efficiency, we introduce a phase-coherent filter, called a directional filter, that overcomes the 50% theoretically optimal efficiency of a half-wave resonator filter. The low spectral resolution results in only 22 filters and MKID detectors to cover the full octave from 135 GHz to 270 GHz. By leveraging the natural multiplexing capabilities of MKIDs, a future large imaging spectrometer can be realized with minimal readout requirements.
13102-156
On demand | Presented live 20 June 2024
Show Abstract +
We will present an update on the TIME project. TIME is a mm-wavelength spectrometer spanning the frequency range of 200-300 GHz, designed to probe ionized carbon ([CII]) from redshift 5-9 and carbon monoxide (CO) from redshift 0.5-2 using line intensity mapping. I will review the instrument and provide an update on current status and plans for future science observation. TIME will also measure galaxy clusters using the kSZ effect which will be important tools to understand systematics in cluster catalogs.
13102-157
20 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
We developed a vacuum window made of high-resistivity silicon for integration into the DESHIMA receiver, which is installed on the ASTE telescope in the Chilean Atacama desert. DESHIMA is a spectrometer operating between 220 to 440 GHz and has 124 mm diameter vacuum window . To reduce the substantial reflections expected from the bare silicon we laser-ablated sub-wavelength structures (SWSs) over an optically active circular area with a diameter of 67 mm using an ultra-short pulsed laser. The measured average transmittance within the pass band and the transmittance at any frequency are above 0.9. The window has been subjected to an atmospheric pressure difference for 10 days with no apparent vacuum leak. In this presentation, we introduce the design, including the tradeoff of the material choices, the fabrication, and the evaluation of its performance. To our knowledge, this is the first vacuum window made of silicon with the SWS anti-reflection surface operating in this frequency, a fractional bandwidth exceeding 65%, on an astronomical receiver at the observational site.
Show Abstract +
The Terahertz Intensity Mapper (TIM) is a NASA far-infrared balloon mission designed to characterize the star formation history of the Universe. During its science flight TIM will spectroscopically map two well-studied target fields (GOODS-S, SPT Deep Field) to measure the intensity of the redshifted 158 um emission line of ionized carbon over a redshift range 0.5-1.7 (lookback times of 5-10 Gyr). From these observations we will be able to constrain the evolution of star formation through cosmic time and determine the large-scale 3D structure of star forming galaxies using line intensity mapping. To achieve this goal, TIM will fly a 2-meter warm telescope that feeds two cryogenic long-slit grating spectrometers. Each spectrometer has a 1.0 degree field of view slit and together the spectrometers cover the 240 to 420 um wavelength range at an R~250. Each spectrometer will employ a focal plane of ~3600 dual-polarization horn-coupled Kinetic Inductance Detectors, which are monitored using a RF system-on-chip readout. This poster presents an overview of the experiments hardware and expected scientist results.
13102-159
20 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
The South Pole Telescope Summertime Line Intensity Mapper (SPT-SLIM) is demonstrating the use of on-chip spectrometers for millimeter-wave line intensity mapping, a new technique that will measure large-scale structure at redshifts higher than traditional galaxy surveys. We use a Toptica Terascan narrowband source to characterize the R~200 filter-bank spectrometer bandpasses with high resolution and present a measurement setup that includes optical attenuation and contemporaneous power monitoring. We present detailed spectral profiles, in addition to array-level statistics such as band centers and bandwidths.
13102-161
On demand | Presented live 20 June 2024
Show Abstract +
The Epoch of Reionization Spectrometer is intended for the Fred Young Submillimeter Telescope, located in Chile. EoR-Spec’s objective is to create 3-D slices of the universe for analysis of star/galaxy evolution and the underlying dark matter structure. Using Line Intensity Mapping, it measures the redshifted far-IR [CII] and [OIII] fine structure lines over the redshift intervals 3.5-8 and 7-15. EoR-Spec utilizes a cryogenic, scanning Fabry-Perot Interferometer, whose 2 parallel mirrors form a resonating cavity, transmitting particular frequencies to the detector depending on the cavity spacing. Micro-Epsilon capacitive displacement sensors are needed to monitor this spacing. The goal of this research is to verify the performance of these sensors and to characterize any systematic oddities in their behavior. We detect a warm-up effect, measure a significant temperature dependence, and verify that, despite the previously mentioned effects, the sensors still provide sufficient accuracy to serve their intended purpose in EoR-Spec.
13102-162
On demand | Presented live 20 June 2024
Show Abstract +
The Epoch of Reionization Spectrometer (EoR-Spec) is an instrument module in the Prime-Cam receiver on the upcoming Fred Young Submillimeter Telescope (FYST), a six-meter aperture telescope to be located on Cerro Chajnantor in the Atacama Desert, Chile. EoR-Spec will reveal reionization and galaxy formation in the Universe at z~3.5 to 8 through [CII] line intensity mapping. To fulfill spectral resolution requirements (R=100), the module incorporates a scanning Fabry-Perot interferometer comprising two parallel, highly reflective silicon-based mirrors optimized for high transmission and uniform finesse. Here we present an updated account of the ongoing efforts involved in the characterization of silicon mirrors and the mounting test conducted for the EoR-Spec instrument.
13102-163
On demand | Presented live 20 June 2024
Show Abstract +
The EXperiment for Cryogenic Large-Aperture Intensity Mapping (EXCLAIM) is a balloon-borne telescope designed to survey star formation over cosmological time scales using intensity mapping in the 420 – 540 GHz frequency range. EXCLAIM uses a fully cryogenic telescope coupled to six on-chip spectrometers featuring kinetic inductance detectors to achieve high sensitivity, allowing for fast integration in dark atmospheric windows. The telescope receiver is cooled to 1.7 K by immersion in a superfluid helium bath and enclosed in a superfluid-tight shell with a meta-material anti-reflection coated silicon window. In addition to the optics and the spectrometer package, the receiver contains the magnetic shielding, the cryogenic segment of the spectrometer readout, and the sub-Kelvin cooling system. A three-stage continuous adiabatic demagnetization refrigerator keeps the detectors at 100 mK while a 4He sorption cooler provides a 900 mK thermal intercept for mechanical suspensions and coaxial cables. We present the design of the EXCLAIM receiver and report on the flight-like testing of major receiver components, including the superfluid-tight receiver window and the sub-Kelvin coolers.
13102-164
On demand | Presented live 20 June 2024
Show Abstract +
A pulsar digital platform for the Sardinia Radio Telescope will be outlined. The digital backend has a SKARAB (Square Kilometer Array Reconfigurable Application Board) system as a main engine, which is capable to digitize and process data for all of the pulsar scientific applications of a single-dish radio telescope.
13102-165
On demand | Presented live 20 June 2024
Show Abstract +
The Lunar Surface Electromagnetics Experiment, LuSEE-Night, is a low-frequency radio astronomy experiment that searches the cosmic Dark Ages signal on the radio-quiet farside of the Moon. LuSEE-Night carries a radio frequency spectrometer consisting of a set of antennas, analog and digital processing electronics, and will be launched by the NASA Commercial Lunar Payload Services (CLPS) in 2025. The flight model (FM) of the four-channel radio spectrometer has been designed, developed, and characterized. Linearity, gain, noise, and input impedance have been measured for the frequency range 0.5-50 MHz and agree well with the SPICE simulation. We have confirmed that the FM meets the mission requirements.
Session PS12:
Posters - Optics and Components II
20 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Thursday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13102-166
On demand | Presented live 20 June 2024
Show Abstract +
We have been developing a wideband heterodyne receiver for simultaneous observations in isotopologue CO lines at 230 and 345 GHz bands with dual-polarization to observe molecular clouds in nearby star-forming regions and along the Galactic Plane. To achieve dual-band and dual-polarization observations and contribute to the future development of Atacama Large millimeter/submillimeter Array and Very Long Baseline Interferometry telescopes, we have been developing a wideband waveguide multiplexer, wideband orthomode transducer (OMT), and wideband circular polarizer (CP). In 2021, we installed a prototype multiplexer in the 1.85–m mm–submm telescope of Osaka Metropolitan University and succeeded in commissioning observations simultaneously in 230 and 345 GHz bands with single-polarization. We are currently working on improving the multiplexer and developing the wideband OMT and CP. In this conference, we will present the development of the prototype wideband receiver and the development status of a new design multiplexer, the OMT, and the CP.
13102-167
On demand | Presented live 20 June 2024
Show Abstract +
Future millimeter wavelength experiments aim to both increase aperture diameters and broaden bandwidths to increase the sensitivity of the receivers. These changes produce a challenging anti-reflection (AR) design problem for refracting and transmissive optics. The higher frequency plastic optics require consistently thin polymer coats across a wide area, while wider bandwidths require multilayer designs. We present multilayer AR coats for plastic optics of the high frequency BICEP Array receiver (200-300 GHz) utilizing an expanded polytetrafluoroethylene (ePTFE) membrane, layered and compressively heat-bonded to itself. This process allows for a range of densities (from 0.3g/cc to 1g/cc) and thicknesses (>0.05mm) over a wide radius (30cm), opening the parameter space of potential AR coats in interesting directions. The layered ePTFE membrane has been combined with other polymer layers to produce band average reflected powers between 0.2% and 0.6% on high density polyethylene and a thin high modulus polyethylene window, respectively.
13102-168
On demand | Presented live 20 June 2024
Show Abstract +
We present transmission and loss measurements of 3D printed alumina and reflectance measurement of a sample
with 3D printed sub-wavelength structures anti-reflection coatings (SWS-ARC). For a band between 160 and 700
GHz we find an index of refraction n = 3.11 ± 0.01 and loss tan δ = 0.002 ± 0.003. Transmission measurements
between 160 and 250 GHz of a sample with SWS-ARC 3D printed on one side give a reduction of reflectance from
a maximum of 64% to a maximum of 31% over the band, closely matching predictions. These first measurements
of the index and loss over this frequency band suggest that the material could be useful for astrophysical
applications.
13102-169
On demand | Presented live 20 June 2024
Show Abstract +
Current and future experiments observing the cosmic microwave background require a detailed understanding of
optical performance at cryogenic temperatures. Pre-deployment analysis of optics can be performed in custom-
engineered cryogenic test beds, such as Mod-Cam, a first light camera for the CCAT project. This work presents
studies of the mechanical and thermal performance of CryoSim, a model of a generic cylindrical 4-K cryostat
cooled with a commercial pulse tube cryocooler that can be used to characterise optical components and full
reimaging optical systems. CryoSim is extensively parametrised, allowing the joint analysis and optimisation
of mechanical and thermal performance via finite element methods. Results from this model are validated
against measured cooldown data of the Mod-Cam cryostat. Due to the extensive parametrisation of the model,
significant modifications of the cryostat geometry may be implemented to be representative of any system the
scientific community may desire, and validation of thermal and mechanical performance can be carried out
rapidly.
13102-171
20 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
Silicon-platelet feedhorn technology is well established at millimeter wavelengths and can provide significant advantages over traditional direct-machined metal feedhorns. Past experiments have required just a few arrays, each built from ~50x lithographically processed wafers – a practical amount for a research lithographic microfabrication facility. However, scaling production to dozens of such arrays for future large-scale experiments may be unfeasible. Here we explore an alternative fabrication approach: laser-micromachining of silicon wafers – a scalable solution with potential advantages in fabrication speed, labor, and throughput.
We characterize a prototype array of laser-micromachined feedhorns designed for operation in the band 80–160 GHz. We compare the optical performance of these horns at room-temperature to horns produced using the traditional DRIE process, and contrast both against simulation. Furthermore, we explore additional potential advantages to laser-micromachining, e.g. sidewall control and thicker wafers. Finally, we share fabrication experience and discuss the outlook for high-throughput feedhorn production using laser-machined wafers.
Session PS13:
Posters - CMB Instruments III
20 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Thursday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13102-172
On demand | Presented live 20 June 2024
Show Abstract +
The search for the polarized imprint of primordial gravitational waves in the cosmic microwave background (CMB) as direct evidence of cosmic inflation requires exquisite sensitivity and control over systematics. The next-generation CMB-S4 project intends to improve upon current-generation experiments, by deploying a significantly greater number of highly-sensitive detectors combined with refined instrument components based on designs from field-proven instruments. The Precursor Small Aperture Telescope (PreSAT) is envisioned as an early step to this next generation, which will test prototype CMB-S4 technologies within an existing BICEP Array receiver, with the aim of enabling full-stack laboratory testing and early risk retirement. The polarimeter will utilize new 95/155 GHz dichroic prototype detectors developed for CMB-S4, along with a prototype readout chain and prototype optics manufactured with wide-band anti-reflection coatings.
13102-173
On demand | Presented live 20 June 2024
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The Simons Observatory (SO) is a group of next-generation telescopes dedicated to observing the polarized cosmic microwave background (CMB), transients, and more. The Observatory consists of four new telescopes and instruments, with over 60,000 superconducting detectors total, located at 5200m altitude in the Atacama Desert of Chile. During observations, it is important to ensure the detectors, telescope platforms, calibration and receiver hardware, and site hardware are within operational bounds. To facilitate rapid response when problems arise with any part of the system, it is essential that alerts are generated and distributed to appropriate personnel if components exceed these bounds. Similarly, alerts are generated if the quality of the data has become degraded. In this paper, we describe the SO alarm system we developed within the larger observatory control system (OCS) framework, including the data sources, alert architecture and implementation. We also present results from deploying the alarm system during commissioning of the SO telescopes and receivers.
13102-174
On demand | Presented live 20 June 2024
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LiteBIRD, a forthcoming satellite mission, aims to measure the polarization of the Cosmic Microwave Background (CMB) across the entire sky. The experiment will employ three telescopes, Transition-Edge Sensor (TES) bolometers and rotating Half-Wave Plates (HWPs) at cryogenic temperatures to ensure high sensitivity and systematic effects mitigation.
This study is focused on the Mid- and High-Frequency Telescopes (MHFT), which will use rotating metal mesh HWPs. We investigate how power variations due to HWP differential emissivity and transmittance combine with TES non-linear responsivity, resulting in an effective instrumental polarization. We present the results of simulations for the current HWP design, modeling the TES deviation from linearity as a second-order response. We quantify the level of acceptable residual non-linearity assuming the mission requirement on the tensor-to-scalar ratio, δr < 0.001. Moreover, we provide an accuracy requirement on the measurement of TES responsivity non-linearity level for MHFT channels. Lastly, we present possible mitigation methods to be developed in future studies.
13102-175
On demand | Presented live 20 June 2024
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As millimeter wave experiments refine their optical chains, precisely characterizing their optical materials under cryogenic conditions becomes increasingly important. For instance, as the aperture sizes and bandwidths of millimeter wave receivers increase, the design of antireflection coatings becomes progressively more constrained by an accurate measure of material optical properties in order to achieve forecasted performance. Likewise, understanding dielectric and scattering losses is relevant to photon noise modeling in presently-deploying receivers such as BICEP Array and especially to future experiments such as CMB-S4. High quality factor Fabry–Pérot open resonant cavities provide an elegant means for measuring these optical properties. Employing a hemispherical confocal resonator that is compatible with a 4 Kelvin cryostat, we can measure the dielectric and scattering losses of low-loss materials at both ambient and cryogenic temperatures. We review the design, characterization, and metrological applications of quasioptical cavities commissioned for measuring the dielectric materials in the BICEP3 (95 GHz) and BICEP Array mid-frequency (150 GHz) optics.
13102-176
On demand | Presented live 20 June 2024
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The Simons Observatory Large Aperture Telescope (LAT) is a 6 meter telescope located at in Chile. For the results discussed here the LAT contained ∼ 11, 000 polarization sensitive detectors in a dark configuration. We provide an in depth characterization of our detector noise, validating our expectations of the noise levels and verifying that we will be dominated by photon noise when observing. We also characterize the instrument’s systematics, in particular scan-synchronous systematics which could not be studied previously. Data taken while scanning was used to produce dark maps, verifying the efficacy of our data reduction and mapmaking pipelines.
13102-177
On demand | Presented live 20 June 2024
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A new facility instrument open to the scientific community is MISTRAL. The MIllimetrer Sardinia radio Telescope Receiver based on Array of Lumped elements KIDs (MISTRAL) is a millimetric multi pixel camera, mounted at the Gregorian focus of the Sardinia Radio Telescope (SRT), working in the W-band that will be able to study many scientific cases, from the ‘missing baryons’ problem to extragalatic astrophysics, morphology of galaxy cluster and the search of the Cosmic Web through high angular resolution measurements of the Sunyaev-Zel’dovich effect.
We present the current state of the map-making and data fitlering software that we plan to use for future observation. This software aims to analyze the simulated observations of a target, filter the data from instrumental noise and produce a map, employing a customized common mode removal.
13102-178
20 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
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LiteBIRD is a JAXA strategic L-Class mission designed to search for primordial gravitational waves produced during the inflationary phase of the Universe. This is achieved through measurements of their imprint on the polarization of the cosmic microwave background (CMB). To fulfill the scientific objectives, observations must be made over a wide range of frequencies (34 GHz - 448 GHz), which is accomplished by three telescopes: the Low-Frequency Telescope (LFT) led by JAXA and the Middle & High-Frequency Telescopes (MHFT) under European responsibility and led by CNES. To withstand the launch, comply with satellite requirements, and minimize the mass of the mechanical structure, we conducted finite element modeling of the entire MHFT, incorporating both modal and quasi-static load analyses. A nodal thermal study evaluated the static thermal loads of the instruments and their sensitivity to sinusoidal disturbances caused by the ADR cooling system. This paper outlines the design methodology of the MHFT and summarizes the initial results and conclusions.
13102-179
On demand | Presented live 20 June 2024
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The accurate knowledge of the beam shape is crucial for any CMB instrument. In the framework of the future LiteBIRD space mission, we present the preliminary study performed on the optical breadboard of one of its instruments, in order to validate the modeling tools and the level of accuracy achievable on the experimental RF characterisation. A simple one-lens system fed by a corrugated horn has been developed to mimic the beam of the future MHFT. Measurement results in W-band (75 - 110 GHz) are compared with the RF model, showing a very good agreement between experimental beam patterns and simulations down to a level of about - 70dB.
13102-181
20 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
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The Simons Observatory Small Aperture Telescopes (SATs) with 0.4 m aperture observe cosmic microwave background at 5,200 m altitude in the Atacama Desert of Chile. One of the SATs with sensitivity to low frequency (25-45 GHz) bands is currently under development in Japan. The SAT has ~1,000 Transition Edge Sensor (TES) bolometers. The detectors are operated at 100 mK and cooled by a dilution refrigerator. Among the critical factors are the reduction of the temperature gradient across the thermal strap between the focal plane and the dilution refrigerator and a robust support structure to avoid mechanical resonance. In this poster, we will report on the design and optimization of the thermal strap. We simulated the eigenfrequency that should be high enough to prevent self-heating due to vibration. We also optimized the thermal contact conductance, which could be a bottleneck of the thermal conductance of the thermal strap.
13102-182
CANCELED: A novel mechanical design for fast high-throughput room-temperature electrical probing of chips for BICEP Array
20 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
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Current and future Cosmic Microwave Background (CMB) experiments require tens of thousands detectors to reach the required sensitivity to measure the CMB polarization. Proper operation of the detectors integrated with their cold readout electronics components needs hundreds of functional chips working at cryogenic temperatures. This is true for both the Time Domain Multiplexing and the umux multiplexing readout architectures. The high-frequency channels of the Bicep Array telescopes, and the future CMB-S4, require the room temperature screening of hundreds to thousands of Mux and Nyquist chips.
Electrical probing of chips is traditionally done by wire bonding Al bonds between the chips under test and a testbed board. The wire bonding procedure is time consuming. Moreover, the validated chips need to be removed from the testbed board and integrated on another board for a cryogenic test.
We present a novel mechanical design which does not require wire bonding the chips. The design presented here has potential use way beyond the readout chips for CMB telescopes addressed in this work.
13102-183
On demand | Presented live 20 June 2024
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In this paper, we present one possible baseline design of a SKYLOAD dedicated to the LiteBIRD Med- and High-Frequency Telescopes (MHFT) on ground characterization and calibration, currently under development by our research group. The SKYLOAD is composed from anechoic panels with anechoic cone array honeycomb structures made of microwave absorbing polymer compatible with vacuum cryogenic environment. Some engineering solutions have been analyzed to ensure effective thermal contact without significantly increasing the associated thermal stresses. An original manufacturing method of the proposed anechoic panels, involving polymer casting, is currently under consideration.
13102-184
On demand | Presented live 20 June 2024
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Antenna-coupled kinetic inductance detectors (KIDs) are promising solutions for the next generation of cosmic microwave background (CMB) experiments, where focal plane arrays require a significant increase in detector number and multi-band observation. We present the design and fabrication of multichroic pixels using this concept for CMB B-mode polarization observation. The pixel incorporates an improved dual bowtie slot antenna placed at the second focus of an elliptical lens, operating in a frequency range of 100–300 GHz. We aim to deliver bandwidths exceeding 20% for two CMB-targeted subbands at 150 and 220 GHz, while maintaining effective linear polarization sensitivity with a cross-polarization level below -17 dB across the entire range. The captured signal is then passed through a superconducting microstrip low-pass filter to remove excess signal before being fed into the diplexer, where the two bands are separated. These bands are then coupled to corresponding KIDs, which modify the resonant frequency and quality factor of the resonators. The demonstration sample is fabricated using 5 photomask layers, employing only Nb and Al, and is underway for testing.
13102-190
On demand | Presented live 20 June 2024
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We present the design and testing of a precision Cosmic Microwave Background detector bandpass calibration technique. The Frequency-selectable Laser Source (FLS) uses a laser source that has a wide frequency range with narrow linewidth and fine resolution. The laser source is placed inside a neutral attenuating assembly, which uses prisms to vary the power of the laser. We measure the passbands and out-of-band leakage of the detectors inside an ultra-high frequency optics tube in its full configuration.
Conference Chair
SRON Netherlands Institute for Space Research (Netherlands), Delft Univ. of Technology (Netherlands)
Program Committee
National Institute of Standards and Technology (United States)
Program Committee
SRON Netherlands Institute for Space Research (Netherlands)
Program Committee
NASA Goddard Space Flight Ctr. (United States), Johns Hopkins Univ. (United States)
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