This PDF file contains the front matter associated with SPIE Proceedings Volume 8443, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

It will be decades before a flagship class mission in the ultraviolet will be implemented to succeed the Hubble Space Telescope. However, advances in technology can enable smaller aperture systems to achieve and surpass HST sensitivity by reducing attacking the noise portion of the signal/noise calculation. Through the use of ultra-low noise photon counting detectors, low scatter optics, and optical design, instruments in the ultraviolet can be developed that can attack critical science questions that cannot be addressed by current instrumentation, even in an Explorer class mission.

The various demands on funding agencies make it difficult to sustain the level of expenditure required to provide the broad range of space astronomy missions that the research community would like to have available. Multi-billion pound/dollar observatories such Chandra, XMM-Newton and HST have been enormously successful, but JWST has been delayed and plans for an equivalent large X-ray mission seem to be on-hold. Furthermore, the medium size ESA and NASA missions provide only a small number of opportunities over the next decade. Much exciting and important science, by default, will not be done. If satellite mission costs could be reduced significantly, by a factor of 5-10, we would open up a new parameter space of opportunity that is not currently offered by any agency. Significant improvement in instrument technology coupled with simplification of optical systems and the development of efficient, high performance small satellite platforms and ground systems has led to the prospect of the development of some low-cost opportunities. In this paper, we outline one such possible mission, based on a successful sounding rocket-borne payload. This comprises a high throughput normal incidence extreme ultraviolet spectrometer, with the design adapted for accommodation on the SSTL 300 platform. We make use of a segmented diffraction grating to provide an overall wavelength coverage from ~170-260Å by tuning the multi-layers of the individual elements to different, overlapping ranges. We outline the capability and science goals of the mission, and how they influence the design and operation of the satellite platform. We conclude with a discussion of how missions of this type operating both as constellations and as formation flying sparse apertures, could offer a scientifically viable alternative to monolothic 'great observatory' missions in the future.

The World Space Observatory Ultraviolet (WSO-UV) is a multinational mission under the leadership of Russia with contributions of Spain and Germany. The mission is part of the Spektrum series and launch is currently scheduled for 2016. It consists of a 1.7m mirror focusing on spectrographs in the range of 102-310 nm withh a resolution of R ≥ 55,000 for high resolution spectral observations, a long-slit-spectrograph for spatially resolved observations and an imager. According to the Phase-B-Study all spectrographs will use the same detectors built by the IAAT. These spectrographs are designed to observe cosmic plasma with temperatures of several ten thousands Kelvin and atomic transition lines of all important atoms and molecuules like H2, CO, OH eetc. In knowledge about the formation of galaxies and analyze the atmospheres of extrasolar planets and protoplanetary discs. To achieve these goals the IAAT designed in cooperation with the Leibniz-Institute for Analytical Sciences (ISAS Berlin) the spectrographs. In addition Tubingen develops and builds a new type of michrchannel plate detector based on gallim nitride cathods and a cross-strip-anode.

A key astrophysical theme that will drive future UV/optical space missions is the life cycle of cosmic matter, from the flow of intergalactic gas into galaxies to the formation and evolution of exoplanetary systems. Spectroscopic systems capable of delivering high resolution with low backgrounds will be essential to addressing these topics. Towards this end, we are developing a rocket-borne instrument that will serve as a pathfinder for future high-sensitivity, highresolution UV spectrographs. The Colorado High-resolution Echelle Stellar Spectrograph (CHESS) will provide 2 km s-1 velocity resolution (R = 150,000) over the 100 - 160 nm bandpass that includes key atomic and molecular spectral diagnostics for the intergalactic medium (H I Lyman-series, O VI, N V, and C IV), exoplanetary atmospheres (H I Lyman-alpha, O I, and C II), and protoplanetary disks (H2 and CO electronic band systems). CHESS uses a novel mechanical collimator comprised of an array of 10 mm x 10 mm stainless steel tubes to feed a low-scatter, 69 grooves mm-1 echelle grating. The cross-disperser is a holographically ruled toroid, with 351 grooves mm-1. The spectral orders can be recorded with either a 40 mm cross-strip microchannel plate detector or a 3.5k x 3.5k δ-doped CCD. The microchannel plate will deliver 30 μm spatial resolution and employs new 64 amp/axis electronics to accommodate high count rate observations of local OB stars. CHESS is scheduled to be launched aboard a NASA Terrier/Black Brant IX sounding rocket from White Sands Missile Range in the summer of 2013.

The Solar Orbiter mission will explore the connection between the Sun and its heliosphere, taking advantage of an orbit approaching the Sun at 0.28 AU. As part of this mission, the Extreme Ultraviolet Imager (EUI) will provide full-sun and high-resolution image sequences of the solar atmosphere at selected spectral emission lines in the extreme and vacuum ultraviolet. To achieve the required scientific performances under the challenging constraints of the Solar Orbiter mission it was required to further develop existing technologies. As part of this development, and of its maturation of technology readiness, a set of breadboard and prototypes of critical subsystems have thus been realized to improve the overall instrument design. The EUI instrument architecture, its major components and sub-systems are described with their driving constraints and the expected performances based on the breadboard and prototype results. The instrument verification and qualification plan will also be discussed. We present the thermal and mechanical model validation, the instrument test campaign with the structural-thermal model (STM), followed by the other instrument models in advance of the flight instrument manufacturing and AIT campaign.

The Interface Region Imaging Spectrograph (IRIS) is a NASA SMall EXplorer mission scheduled for launch in January 2013. The primary goal of IRIS is to understand how the solar atmosphere is energized. The IRIS investigation combines advanced numerical modeling with a high resolution UV imaging spectrograph. IRIS will obtain UV spectra and images with high resolution in space (0.4 arcsec) and time (1s) focused on the chromosphere and transition region of the Sun, a complex interface region between the photosphere and corona. The IRIS instrument uses a Cassegrain telescope to feed a dual spectrograph and slit-jaw imager that operate in the 133-141 nm and 278-283 nm ranges. This paper describes the instrument with emphasis on the imaging spectrograph, and presents an initial performance assessment from ground test results.

METIS, the “Multi Element Telescope for Imaging and Spectroscopy”, is a coronagraph selected by the European Space Agency to be part of the payload of the Solar Orbiter mission to be launched in 2017. The unique profile of this mission will allow 1) a close approach to the Sun (up to 0.28 A.U.) thus leading to a significant improvement in spatial resolution; 2) quasi co-rotation with the Sun, resulting in observations that nearly freeze for several days the large-scale outer corona in the plane of the sky and 3) unprecedented out-of-ecliptic view of the solar corona. This paper describes the experiment concept and the observational tools required to achieve the science drivers of METIS. METIS will be capable of obtaining for the first time: • simultaneous imaging of the full corona in polarized visible-light (590-650 nm) and narrow-band ultraviolet HI Lyman α (121.6 nm); • monochromatic imaging of the full corona in the extreme ultraviolet He II Lyman α (30.4 nm); • spectrographic observations of the HI and He II Ly α in corona. These measurements will allow a complete characterization of the three most important plasma components of the corona and the solar wind, that is, electrons, hydrogen, and helium. This presentation gives an overview of the METIS imaging and spectroscopic observational capabilities to carry out such measurements.

We report science and development activities of the X-ray/EUV telescope for the Japanese Solar-C mission whose projected launch around 2019. The telescope consists of a package of (a) a normal-incidence (NI) EUV telescope and (b) a grazing-incidence (GI) soft X-ray telescope. The NI telescope chiefly provides images of low corona (whose temperature 1 MK or even lower) with ultra-high angular resolution (0.2-0.3"/pixel) in 3 wavelength bands (304, 171, and 94 angstroms). On the other hand, the GI telescope provides images of the corona with a wide temperature coverage (1 MK to beyond 10 MK) with the highest-ever angular resolution (~0.5"/pixel) as a soft X-ray coronal imager. The set of NI and GI telescopes should provide crucial information for establishing magnetic and gas-dynamic connection between the corona and the lower atmosphere of the Sun which is essential for understanding heating of, and plasma activities in, the corona. Moreover, we attempt to implement photon-counting capability for the GI telescope with which imaging-spectroscopy of the X-ray corona will be performed for the first time, in the energy range from ~0.5 keV up to 10 keV. The imaging-spectroscopic observations will provide totally-new information on mechanism(s) for the generation of hot coronal plasmas (heated beyond a few MK), those for magnetic reconnection, and even generation of supra-thermal electrons associated with flares. An overview of instrument outline and science for the X-ray photoncounting telescope are presented, together with ongoing development activities in Japan towards soft X-ray photoncounting observations, focusing on high-speed X-ray CMOS detector and sub-arcsecond-resolution GI mirror.

We present the status of LAUE, a project supported by the Italian Space Agency (ASI), and devoted to develop Laue lenses with long focal length (from 10–15 meters up to 100 meters), for hard X–/soft gamma–ray astronomy (80-600 keV). Thanks to their focusing capability, the design goal is to improve the sensitivity of the current instrumention in the above energy band by 2 orders of magnitude, down to a few times 10⁻⁸ photons/(cm² s keV).

In order to explore MeV gamma-ray astronomy, we have developed the Electron Tracking Compton Camera (ETCC) consisting of a Time projection Chamber based on the micro pixel gas counter and pixel array scintillators. By measuring the track of a recoil electron in the TPC event by event, the ETCC measures the direction of each gamma-ray, and provides both good background rejection and an angular resolution over ~1 degree. A 1m-cubic size ETCC in satellite would be a good candidate for an All sky MeV gamma-ray survey of a wide band energy region of 0.1-100MeV with several ten times better sensitivity than COMPTEL. Already we carried out a balloon experiment with a small ETCC (Sub-MeV gamma ray Imaging Loaded-on-balloon Experiment: SMILE-I) in 2006, and measured diffuse cosmic and atmosphere gamma rays. We are now constructing a 30cm-cube ETCC to catch gamma-rays from the Crab and terrestrial gamma-ray bursts at the North Pole from 2013 (SMILE-II project). Terrestrial gamma-ray bursts are generated by relativistic electron precipitation in the Pole region. Recently performance of tracking a recoil electron has been dramatically improved, which may enable us to reach the ideal efficiency expected for the detector. In addition, we mention about the unique capability to find a high-z Gamma-Ray Bursts beyond z>10 by ETCC, in particular long duration GRBs over 1000 sec, which are expected to be due to POP-III stars.

MeV and sub-MeV energy band from ~200 keV to ~2 MeV contains rich information of high-energy phenomena in the universe. The CAST (Compton Telescope for Astro and Solar Terrestrial) mission is planned to be launched at the end of 2010s, and aims at providing all-sky map in this energy-band for the first time. It is made of a semiconductor Compton telescope utilizing Si as a scatterer and CdTe as an absorber. CAST provides allsky sub-MeV polarization map for the first time, as well. The Compton telescope technology is based on the design used in the Soft Gamma-ray Detector (SGD) onboard ASTRO-H, characterized by its tightly stacked semiconductor layers to obtain high Compton reconstruction efficiency. The CAST mission is currently planned as a candidate for the small scientific satellite series in ISAS/JAXA, weighting about 500 kg in total. Scalable detector design enables us to consider other options as well. Scientific outcome of CAST is wide. It will provide new information from high-energy sources, such as AGN and/or its jets, supernova remnants, magnetors, blackhole and neutron-star binaries and others. Polarization map will tell us about activities of jets and reflections in these sources, as well. In addition, CAST will simultaneously observe the Sun, and depending on its attitude, the Earth.

The Advanced Energetic Pair Telescope (AdEPT) is being developed at GSFC as a future NASA MIDEX mission to explore the medium-energy (5–200 MeV) gamma-ray range. The enabling technology for AdEPT is the Three- Dimensional Track Imager (3-DTI), a gaseous time projection chamber. The high spatial resolution 3-D electron tracking of 3-DTI enables AdEPT to achieve high angular resolution gamma-ray imaging via pair production and triplet production (pair production on electrons) in the medium-energy range. The low density and high spatial resolution of 3-DTI allows the electron positron track directions to be measured before they are dominated by Coulomb scattering. Further, the significant reduction of Coulomb scattering allows AdEPT to be the first medium-energy gamma-ray telescope to have high gamma-ray polarization sensitivity. We review the science goals that can be addressed with a medium-energy pair telescope, how these goals drive the telescope design, and the realization of this design with AdEPT. The AdEPT telescope for a future MIDEX mission is envisioned as a 8 m³ active volume filled with argon at 2 atm. The design and performance of the 3-DTI detectors for the AdEPT telescope are described as well as the outstanding instrument challenges that need to be met for the AdEPT mission.

We describe the space project of Ultra-Fast Flash Observatory (UFFO) which will observe early optical photons from gamma-ray bursts (GRBs) with a sub-second optical response, for the first time. The UFFO will probe the early optical rise of GRBs, opening a completely new frontier in GRB and transient studies, using a fast response Slewing Mirror Telescope (SMT) that redirects optical path to telescope instead of slewing of telescopes or spacecraft. In our small UFFO-Pathfinder experiment, scheduled to launch aboard the Lomonosov satellite in 2012, we use a motorized mirror in our Slewing Mirror Telescope instrument to achieve less than one second optical response after X-ray trigger. We describe the science and the mission of the UFFO project, including a next version called UFFO-100. With our program of ultra-fast optical response GRB observatories, we aim to gain a deeper understanding of GRB mechanisms, and potentially open up the z<10 universe to study via GRB as point source emission probes.

CCDs have been used on several successful X-ray space missions including high resolution soft X-ray spectrometers, such as the Reflection Grating Spectrometer on XMM-Newton1 and the LETG and HETG on Chandra2. These instruments had a resolving power of ( E / Δ E) ~300; however, with new technology this can be improved allowing resolution to the thermal limit. In the soft X-ray band (200 eV to 10 keV) a resolution of around 3000 is required resolve all of the possible absorption and emission features. Through the development of instruments for the OP-XGS on IXO3 and the WHIMEx explorer mission4 it has been shown that an instrument capable of this resolution on a spacecraft is possible. CCDs are the ideal detector for use in detection of X-rays at this energy as they provide positional information allowing a high level of spatial resolution and their inherent energy resolution allowing diffracted orders to be separated. This paper will investigate the use of CCDs and possible use of EM-CCDs in soft X-ray spectroscopy. The multiplication of signal in the charge domain can increase the detectability of low energy photons, improving the Signal-to-Noise Ratio. Multiplication gain has been shown to degrade the resolution of a device as described by the Modified Fano Factor5, so this has to be taken into account in instrument design when overlapping spectral orders are needed to achieved the necessary resolution. The use of optical filters on the CCDs and their effect on quantum efficiency at soft X-ray energies is discussed together with possible improvements to existing technology.

The Gas Pixel Detector, developed and continuously improved by Pisa INFN in collaboration with INAF-IAPS, can visualize the tracks produced within a low Z gas by photoelectrons of few keV. By reconstructing the impact point and the original direction of the photoelectrons, the GPD can measure the linear polarization of X-rays, while preserving the information on the absorption point, the energy and the time of arrival of individual photons. The Gas Pixel Detector filled with He-DME mixture at 1 bar is sensitive in the 2-10 keV energy range and this configuration has been the basis of a number of mission proposals, such as POLARIX or XPOL on-board XEUS/IXO, or the X-ray Imaging Polarimetry Explorer (XIPE) submitted in response to ESA small mission call in 2012. We have recently improved the design by modifying the geometry of the absorption cell to minimize any systematic effect which could leave a residual polarization signal for non polarized source. We report on the testing of this new concept with preliminary results on the new design performance.

We present the design and performances of a radiation detector based on plastic scintillating fibers with doubleside readout by means of large-area Single Photon Avalanche Diodes (SPAD). This can be the basic step toward the realization of a large-area, cost-effective position sensitive detector to be employed in future space gammaray observatories. SPADs are silicon devices operated above the junction breakdown voltage (with the typical overvoltage of 5V), for which a single photon interacting in the active region is sufficient to trigger a selfsustainable avalanche discharge. SPADs can thus be used for the detection of very low light levels with a fast time response around 50ps FWHM for single photon detection, without spectroscopic capabilities. Large-area SPAD (500 μm in diameter) have been designed and fabricated at the CNR-IMM facility, with an intrinsic noise lower than 10kHz at -15°C, and are optically coupled to both ends of 3-meter long scintillating fibers, with the same diameter. Double-side readout is required to operate the devices in coincidence (10ns coincidence window), in order to reduce the rate of false detections to the level of 1Hz. The detectors have been tested with minimum ionizing particles at CERN PS demonstrating a detection efficiency larger than 90% and a moderate position resolution along the fiber due to the difference in time of arrival between the two photodetectors. Radiation hardness tests on SPADs have also been carried out, showing that large-area SPADs can be safely employed in low-inclination low Earth orbits.

We report on our activities, currently in progress, aimed at performing accelerator experiments with soft protons and hyper-velocity dust particles. They include tests of different types of X-ray detectors and related components (such as filters) and measurements of scattering of soft protons and hyper-velocity dust particles off X-ray mirror shells. These activities have been identified as a goal in the context of a number of ongoing space projects in order to assess the risk posed by environmental radiation and dust and qualify the adopted instrumentation with respect to possible damage or performance degradation. In this paper we focus on tests for the Silicon Drift Detectors (SDDs) used aboard the LOFT space mission. We use the Van de Graaff accelerators at the University of Tübingen and at the Max Planck Institute for Nuclear Physics (MPIK) in Heidelberg, for soft proton and hyper-velocity dust tests respectively. We present the experimental set-up adopted to perform the tests, status of the activities and some very preliminary results achieved at present time.

The next generation wide-field X-ray telescope (WFXT), to be implemented beyond eRosita and proposed within the NASA RFI call 2011, requires an angular resolution of less than 10 arcsec (with goal of 5”) constant across a wide field of view (1 deg²). To achieve this requirement the design is based on nested modified grazing incidence Wolter-I mirrors with polynomial profiles. Our goals in terms of mass and stiffness can be meet with the use of fused silica glass, a wellknown material with good thermo-mechanical properties and polishability characteristics, together with an innovative polishing approach. Here we present the X-ray calibration results obtained for a prototypal shell tested in fullillumination mode at the Panter/MPE facility.

The mirrors of the International X-ray Observatory (IXO) were based on a large number of high quality segments, aiming at achieving a global spatial resolution better than 5” HEW while giving a large collecting area (around 3m²@ 1 keV). A study concerning the hot slumping of thin glass foils was started in Europe, funded by ESA and led by the Brera Astronomical Observatory (INAF-OAB), for the development of a replication technology based on glass material. The study is currently continuing even after the IXO program has been descoped and renamed ATHENA, in the perspective of using the technology under development for other future missions or applications. INAF-OAB efforts have been focused on the "Direct" slumping approach with convex moulds, meaning that during the thermal cycle the optical surface of the glass is in direct contact with the mould surface. The single mirror segments are made of thin glass plates (0.4 mm thick), with a reflecting area of 200 mm × 200 mm. The adopted integration process foresees the use of glass reinforcing ribs for bonding together the plates in such a way to form a rigid and stiff stack of segmented mirror shells; the stack is supported by a thick backplane. During the bonding process, the plates are constrained in close contact with the surface of a precisely figured integration master by the application of vacuum pump suction. In this way, the springback deformations and the low frequency errors still present in the plates' profile after slumping can be corrected. The status of the technology development is presented in this paper, together with the description and metrology of the prototypes already realized or under construction at the Observatory laboratories.

X-ray astronomy depends upon the availability of telescopes with high resolution and large photon colleX-ray astronomy depends upon the availability of telescopes with high resolution and large photon collecting areas. As astronomical x-ray observations can only be carried out above the atmosphere, these telescopes must necessarily be lightweight. Compounding the lightweight requirement is that an x-ray telescope consists of many nested concentric shells, which further requires that x-ray mirrors must be geometrically thin to achieve high packing efficiency. This double requirement—lightweight and geometrically thin—poses significant technical challenges in fabricating the mirrors and in integrating them into mirror assemblies. This paper reports on the approach, strategy, and status of our program to develop x-ray optics meeting these technical challenges at modest cost. The objective of this technology program is to enable future x-ray missions—including small Explorer missions in the near term, probe class missions in the medium term, and large flagship missions in the long term.ing areas. As astronomical x-ray observations can only be carried out above the atmosphere, these telescopes must necessarily be lightweight. Compounding the lightweight requirement is that an x-ray telescope consists of many nested concentric shells, which further requires that x-ray mirrors must be geometrically thin to achieve high packing efficiency. This double requirement—lightweight and geometrically thin—poses significant technical challenges in fabricating the mirrors and in integrating them into mirror assemblies. This paper reports on the approach, strategy, and status of our program to develop x-ray optics meeting these technical challenges at modest cost. The objective of this technology program is to enable future x-ray missions—including small Explorer missions in the near term, probe class missions in the medium term, and large flagship missions in the long term.

We report on technical progress made over the past year developing thin film piezoelectric adjustable grazing incidence optics. We believe such mirror technology represents a solution to the problem of developing lightweight, sub-arc second imaging resolution X-ray optics. Such optics will be critical to the development next decade of astronomical X-ray observatories such as SMART-X, the Square Meter Arc Second Resolution X-ray Telescope. SMART-X is the logical heir to Chandra, with 30 times the collecting area and Chandra-like imaging resolution, and will greatly expand the discovery space opened by Chandra’s exquisite imaging resolution. In this paper we discuss deposition of thin film piezoelectric material on flat glass mirrors. For the first time, we measured the local figure change produced by energizing a piezo cell – the influence function, and showed it is in good agreement with finite element modeled predictions. We determined that at least one mirror substrate material is suitably resistant to piezoelectric deposition processing temperatures, meaning the amplitude of the deformations introduced is significantly smaller than the adjuster correction dynamic range. Also, using modeled influence functions and IXO-based mirror figure errors, the residual figure error was predicted post-correction. The impact of the residual figure error on imaging performance, including any mid-frequency ripple introduced by the corrections, was modeled. These, and other, results are discussed, as well as future technology development plans.

Our development of ultra light-weight X-ray micro pore optics based on MEMS (Micro Electro Mechanical System) technologies is described. Using dry etching or X-ray lithography and electroplating, curvilinear sidewalls through a flat wafer are fabricated. Sidewalls vertical to the wafer surface are smoothed by use of high temperature annealing and/or magnetic field assisted finishing to work as X-ray mirrors. The wafer is then deformed to a spherical shape. When two spherical wafers with different radii of curvature are stacked, the combined system will be an approximated Wolter type-I telescope. This method in principle allows high angular resolution and ultra light-weight X-ray micro pore optics. In this paper, performance of a single-stage optic, coating of a heavy metal on sidewalls with atomic layer deposition, and assembly of a Wolter type-I telescope are reported.

In this paper we present several novel applications using X-ray mirrors based on Silicon Pore Optics technology, the present baseline technology for large effective area space based X-ray telescopes. By cutting, bending and direct bonding of mirrors cut from silicon wafers we can create a variety of structures in a number of well-defined shapes. One novel application is an X-ray half-mirror for X-ray interferometry applications based on flat, structured Si mirrors bonded to a glass support structure with a large open area ratio. A second application is to use bent silicon single crystals as a focusing Laue lens for soft gamma rays.

Recently developed Critical-Angle Transmission (CAT) grating technology - in combination with x-ray CCD cameras and large collecting-area focusing optics - will enable a new generation of soft x-ray spectrometers with unprecedented resolving power and effective area and with at least an order of magnitude improvement in figures-of-merit for emission and absorption line detection. This technology will be essential to address a number of high-priority questions identified in the Astro2010 Decadal Survey “New Worlds New Horizons” and open the door to a new discovery space. CAT gratings combine the advantages of soft x-ray transmission gratings (low mass, relaxed figure and alignment tolerances, transparent at high energies) and blazed reflection gratings (high broad band diffraction efficiency, utilization of higher diffraction orders to increase resolving power). We report on progress in the fabrication of large-area (31× 31 mm²) free-standing gratings with two levels of low-blockage support structures using highly anisotropic deep reactive-ion etching.

We report our examination of a new X-ray interferometer for observation of celestial objects and our recent work for preparation of laboratory experiments. The new X-ray interferometer is consisting of two at mirrors and one at beam splitter which are used as grazing incident optics. The aimed wave length is a O-K band or a C-K band. The beam splitter and the mirrors are fabricated by Mo/Si multilayer. We measured their atness and found that the measured atness is acceptable for the test experiment. A pin hole X-ray source is also preparing for a laboratory experiment in order to demonstrate a X-ray interference. We investigated a possible observation of accretion disks around BHs and nearby stars. With a reasonable size of the base line, we can measure their size and possibly we can obtain an evidence of a black hole shadow.

Over the past 13 years, the Chandra X-ray Observatory’s ability to provide high resolution X-ray images and spectra have established it as one of the most versatile and powerful tools for astrophysical research in the 21^st century. Chandra explores the hot, x-ray-emitting regions of the universe, observing sources with fluxes spanning more than 10 orders of magnitude, from the X-ray brightest, Sco X-1, to the faintest sources in the Chandra Deep Field South survey. Thanks to its continuing operational life, the Chandra mission now also provides a long observing baseline which, in and of itself, is opening new research opportunities. In addition, observations in the past few years have deepened our understanding of the co-evolution of supermassive black holes and galaxies, the details of black hole accretion, the nature of dark energy and dark matter, the details of supernovae and their progenitors, the interiors of neutron stars, the evolution of massive stars, and the high-energy environment of protoplanetary nebulae and even the interaction of an exo-planet with its star. Here we update the technical status, highlight some of the scientific results, and very briefly discuss future prospects. We fully expect that the Observatory will continue to provide outstanding scientific results for many years to come.

After more than twelve years in orbit and two years beyond the design lifetime, XMM-Newton continues its near faultless operations providing the worldwide astronomical community with an unprecedented combination of imaging and spectroscopic X-ray capabilities together with simultaneous optical and ultra-violet monitoring. The interest from the scientific community in observing with XMM-Newton remains extremely high with the last annual Announcement of Observing Opportunity (AO-11) attracting proposals requesting 6.7 times more observing time than was available. Following recovery from a communications problem in 2008, all elements of the mission are stable and largely trouble free. The operational lifetime if currently limited by the amount of available hydrazine fuel. XMM-Newton normally uses reaction wheels for attitude control and fuel is only used when offsetting reaction wheel speed away from limiting values and for emergency Sun acquisition following an anomaly. Currently, the hydrazine is predicted to last until around 2020. However, ESA is investigating the possibility of making changes to the operations concept and the onboard software that would enable lower fuel consumption. This could allow operations to well beyond 2026.

MVN (Monitor Vsego Neba) - new small X-ray astronomical experiment, which will be mounted on Russian segment of International Space Station. The main scientific goal for the instrument is the precise measurement of cosmic X-ray background in energy range 6-70 keV, which is important for theories of black hole evolution in the Universe. The ultimate aim of the experiment is to reach the accuracy of the CXB measurements, which will allow us to measure the large scale anisotropy of the Cosmic X-ray Background caused by inhomogeneities of the matter distribution in the local Universe. The MVN instrument is a simple collimated spectrometer, equipped with 4 CdTe pixellated detectors. The field of view of the instrument will be scanning the zenith of the ISS. The accuracy of the instrumental background subtraction, which is the main obstacle for the proposed task, will be provided by a cover, which will periodically block the aperture of detectors. According to our estimates, with not unfavourable radiation environment on orbit of ISS during period of operation of MVN we will be able to measure the CXB surface brightness at different sky directions with accuracy better than 1% after 2 years of the experiment. The planned dates of the experiment is 2013-2016.

The Advanced CCD Imaging Spectrometer is an instrument on the Chandra X-ray Observatory. CCDs are vulnerable to radiation damage, particularly by soft protons in the radiation belts and solar storms. The Chandra team has implemented procedures to protect ACIS during high-radiation events including autonomous protection triggered by an on-board radiation monitor. Elevated temperatures have reduced the effectiveness of the on-board monitor. The ACIS team has developed an algorithm which uses data from the CCDs themselves to detect periods of high radiation and a flight software patch to apply this algorithm is currently active on-board the instrument. In this paper, we explore the ACIS response to particle radiation through comparisons to a number of external measures of the radiation environment. We hope to better understand the efficiency of the algorithm as a function of the flux and spectrum of the particles and the time-profile of the radiation event.

We report on our continuing efforts to compare the absolute effective areas of the current generation of CCD instruments onboard the active observatories, specifically: Chandra ACIS, XMM-Newton EPIC (MOS and pn), Suzaku XIS, and Swift XRT, using 1E 0102.2-7219, the brightest supernova remnant in the Small Magellanic Cloud. 1E 0102.2-7219 has strong lines of O, Ne, and Mg below 1.5 keV and little Fe emission to complicate the spectrum. The spectrum of 1E 0102.2-7219 has been well-characterized using the RGS grating instrument on XMM-Newton and the HETG grating instrument on Chandra. We have developed an empirical model that includes Gaussians for the identified lines, an absorption component in the Galaxy, another absorption component in the SMC, and two continuum components with different temperatures. In our fits, the model is highly constrained in that only the normalizations of the four brightest line complexes (the OVII triplet, OVIII Lyα line, the NeIX triplet, and the NeX Lyα) and an overall normalization are allowed to vary, while all other components are fixed. We adopted this approach to provide a straightforward comparison of the measured line fluxes at these four energies. We find that the measured fluxes of the OVII triplet, the OVIII Lyαline, the NeIX triplet, and the NeX Lyαline generally agree to within ±10% for all instruments, with the exception of the OVII triplet and the OVIII Lyαline normalizations for the Suzaku XIS1, XIS2, & XIS3, and the Swift XRT, which can be up to 20%lower compared to the reference model.

The Neutron star Interior Composition ExploreR (NICER) is a proposed NASA Explorer Mission of Opportunity dedicated to the study of the extraordinary gravitational, electromagnetic, and nuclear-physics environments embodied by neutron stars. NICER will explore the exotic states of matter within neutron stars, where density and pressure are higher than in atomic nuclei, confronting theory with unique observational constraints. NICER will enable rotation-resolved spectroscopy of the thermal and non-thermal emissions of neutron stars in the soft (0.2–12 keV) X-ray band with unprecedented sensitivity, probing interior structure, the origins of dynamic phenomena, and the mechanisms that underlie the most powerful cosmic particle accelerators known. NICER will achieve these goals by deploying, following launch in December 2016, an X-ray timing and spectroscopy instrument as an attached payload aboard the International Space Station (ISS). A robust design compatible with the ISS visibility, vibration, and contamination environments allows NICER to exploit established infrastructure with low risk. Grazing-incidence optics coupled with silicon drift detectors, actively pointed for a full hemisphere of sky coverage, will provide photon-counting spectroscopy and timing registered to GPS time and position, with high throughput and relatively low background. In addition to advancing a vital multi-wavelength approach to neutron star studies through coordination with radio and γ-ray observations, NICER will provide a rapid-response capability for targeting of transients, continuity in X-ray timing astrophysics investigations post-RXTE through a proposed Guest Observer program, and new discovery space in soft X-ray timing science.

A “formation flight astronomical survey telescope” (FFAST) is a new project that will cover a large sky area in hard X-ray. In particular, it will focus on the energy range up to 80 keV. It consists of two small satellites that will go in a formation flight. One is an X-ray telescope satellite carrying a “super mirror” and the other is a detector satellite carrying an SDCCD. Two satellites are put into a low earth orbit. They are in a formation flight with a separation of 20 m. Since two satellites are put into Keplerian orbit, the observation direction is moving the sky rather than pointing to a fixed direction. This project will survey a large sky area at hard X-ray region to study the evolution of the universe.

We discuss concepts for high-throughput (effective area 250-1400 cm²), high-resolution (spectral resolving power R > 3500) soft X-ray grating spectroscopy in missions of moderate (probe-class or smaller) scale. Such missions can achieve high-priority scientific objectives identified by the Astro2010 Decadal Survey attainable in no other way, and would provide an essential complement to any future large-area X-ray observatory equipped with non-dispersive spectrometers. We enumerate key science drivers and discuss consequences of various alternative design choices for scientific capability and overall mission size.

SMART-X is a mission concept for a 2.3 m² effective area, 0.5" angular resolution X-ray telescope, with 5' FOV, 1" pixel size microcalorimeter, 22' FOV imager, and high-throughput gratings.

The 2010 Decadal Survey of Astronomy and Astrophysics found the science of the International X-ray Observatory (IXO) compelling, noting that “Large-aperture, time-resolved, high-resolution X-ray spectroscopy is required for future progress on all of these fronts, and this is what IXO can deliver.” In line with Decadal recommendations to reduce cost while maintaining core capabilities, we have developed the Advanced X-ray Spectroscopy and Imaging Observatory (AXSIO). AXSIO reduces IXO's six instruments to two fixed detectors - the imaging X-ray Microcalorimeter Spectrometer and the X-ray Grating Spectrometer. These instruments allow AXSIO to accomplish most of the IXO science goals at a significantly reduced complexity and cost. We present an overview of the AXSIO mission science drivers, its optics and instrumental capabilities, the status of its technology development programs, and the mission implementation approach.

DIOS (Diffuse Intergalactic Oxygen Surveyor) is a small scientific satellite with the main aim of searching warm-hot intergalactic medium using redshifted OVII and OVIII lines. The wide-field spectroscopic capability of DIOS will also bring rich science about the dynamics of cosmic hot plasmas in all spatial scales. The instrument will consist of a 4-stage X-ray telescope and an array of TES microcalorimeters with up to 400 pixels, cooled with mechanical coolers. Hardware development of DIOS and outstanding issues about the payload are described. DIOS will be further developed with international collaboration and will be proposed to the earliest call of JAXA’s small scientific satellite series.

MARX is a portable ray-trace program that was originally developed to simulate event data from the trans- mission grating spectrometers on-board the Chandra X-ray Observatory (CXO). MARX has since evolved to include detailed models of all CXO science instruments and has been further modified to serve as an event simulator for future X-ray observatory design concepts. We first review a number of CXO applications of MARX to demonstrate the roles such a program could play throughout the life of a mission, including its design and calibration, the production of input data products for the development of the various software pipelines, and for observer proposal planning. We describe how MARX was utilized in the design of a proposed future X-ray spectroscopy mission called ÆGIS (Astrophysics Experiment for Grating and Imaging Spectroscopy), a mission concept optimized for the 0.2 to 1 keV soft X-ray band. ÆGIS consists of six independent Critical Angle Transmission Grating Spectrometers (CATGS) arranged to provide a resolving power of 3000 and an effective area exceeding 1000 cm² across its passband. Such high spectral resolution and effective area will permit ÆGIS to address many astrophysics questions including those that pertain to the evolution of Large Scale Structure of the universe, and the behavior of matter at very high densities. The MARX ray-trace of the ÆGIS spectrometer yields quantitative estimates of how the spectrometer’s performance is affected by misalignments between the various system elements, and by deviations of those elements from their idealized geometry. From this information, we are able to make the appropriate design tradeoffs to maximize the performance of the system.

The Micro-X High Resolution Microcalorimeter X-ray Imaging Rocket is a sounding rocket experiment that will combine a transition-edge-sensor X-ray-microcalorimeter array with a conical imaging mirror to obtain high- spectral-resolution images of extended X-ray sources. The target for Micro-X’s first flight (slated for January 2013) is the Puppis A supernova remnant. The Micro-X observation of the bright eastern knot of Puppis A will obtain a line-dominated spectrum with up to 27,000 counts collected in 300 seconds at 2 eV resolution across the 0.3-2.5 keV band. Micro-X will determine the thermodynamic and ionization state of the plasma, search for line shifts and broadening associated with dynamical processes, and seek evidence of ejecta enhancement. We describe the progress made in developing this payload, including the detector, cryogenics, and electronics assemblies.

The possibility to perform polarimetry in the soft X-ray energy band (2-10 keV) with the Gas Pixel Detector, filled with low Z mixtures, has been widely explored so far. The possibility to extend the technique to higher energies, in combination with multilayer optics, has been also hypothesized in the past, on the basis of simulations. Here we present a recent development to perform imaging polarimetry between 6 and 35 keV, employing a new design for the GPD, filled with a Ar-DME gas mixture at high pressure. In order to improve the efficiency by increasing the absorption gap, while preserving a good parallel electric field, we developed a new configuration characterized by a wider gas cell and a wider GEM. The uniform electric field allows to maintain high polarimetric capabilities without any decrease of spectroscopic and imaging properties. We present the first measurements of this prototype showing that it is now possible to perform imaging and spectro-polarimetry of hard X-ray sources.

The background of the Gas Pixel Detector is expected to be negligible for polarimetry of point sources due to the intrinsic low atomic number and density of the He-DME mixtures and to its imaging properties. Also the background for extended sources is expected to be negligible at least down to the smallest flux for sensitive polarimetry in a reasonable observing time. However in the spatial distribution of the background in a laboratory environment we observed an accumulation on the edges of the sensitive plane due to the presence of the nearby cell walls. We recently developed gas pixel detectors with a new design of the gas cell having a larger distance of the walls from the sensitive plane. In this paper we compare the spatial distribution of the measured background for the two design and their residual systematics. Also the impact of the background in the case of SgrB2 a faint extended source in the galactic center region is evaluated.

The 2010 Astrophysics Decadal Survey recommended a significant technology development program towards realizing the scientific goals of the International X-ray Observatory (IXO). NASA has undertaken an X-ray mission concepts study to determine alternative approaches to accomplishing IXO’s high ranking scientific objectives over the next decade given the budget realities, which make a flagship mission challenging to implement. The goal of the study is to determine the degree to which missions in various cost ranges from $300M to $2B could fulfill these objectives. The study process involved several steps. NASA released a Request for Information in October 2011, seeking mission concepts and enabling technology ideas from the community. The responses included a total of 14 mission concepts and 13 enabling technologies. NASA also solicited membership for and selected a Community Science Team (CST) to guide the process. A workshop was held in December 2011 in which the mission concepts and technology were presented and discussed. Based on the RFI responses and the workshop, the CST then chose a small group of notional mission concepts, representing a range of cost points, for further study. These notional missions concepts were developed through mission design laboratory activities in early 2012. The results of all these activities were captured in the final Xray mission concepts study report, submitted to NASA in July 2012. In this presentation, we summarize the outcome of the study. We discuss background, methodology, the notional missions, and the conclusions of the study report.

In September 2011 NASA released a Request for Information on “Concepts for the Next NASA X-ray Astronomy Mission” and formed a Community Science Team to help study the submitted concepts and evaluate their science return relative to the goals identified by the 2010 Astrophysics Decadal Survey “New Worlds, New Horizons” report. After reading the responses and participating in a community workshop, the team identified a number of candidate mission concepts, including one combining advances in large-area precision optics with new X-ray microcalorimeter technology. However, the exact mission requirements (effective area, field of view, point spread function, etc) were not fixed. We will present a range of mission designs, describing the results of the NASA/GSFC Mission Design Lab study of one possible mission along with available deltas that would increase capability or decrease cost.

Wide field X-ray surveys require large field of view telescopes operating in a step and repeat or slow scanning mode in order to cover large areas of the sky efficiently. Here we discuss two similar, yet different designs for a wide field survey mission that can each be accomplished for a cost of less than ~$1B (FY 2012) and that cover many hundreds to several thousand deg², with medium depth ~few × 10⁻¹⁶ erg s⁻¹cm², and several 10’s of degrees with very long exposure time to a depth approaching ~3 × 10⁻¹⁷ erg s⁻¹cm². We review the WFXT design and compare it with the Notional Wide Field Imager (N-WFI) concept that was developed by the NASA CST in response to a charge from NASA to define generic (or notional) missions that can accomplish some (or all) of the IXO science, but at a reduced cost.

The Ultra Violet Imaging Telescope on ASTROSAT Satellite mission is a suite of Far Ultra Violet (FUV: 130 - 180 nm), Near Ultra Violet (NUV: 200 - 300 nm) and Visible band (VIS: 320-550nm) imagers. ASTROSAT is the multi-wavelength mission of ISRO. UVIT will image the sky simultaneously in three channels with a field of view diameter of ~ 28 arcminutes and an angular resolution < 1.8". Two identical co-aligned telescopes (T1, T2) of Ritchey-Chretien configuration (Primary mirror of ~375 mm diameter) collect the celestial radiation and feed the detector systems via a selectable filter on a filter wheel mechanism; gratings are available in the filter wheels of FUV and NUV channels for slitless low-resolution spectroscopy. The photon-counting detector system for each of the 3 channels is generically identical. One of the telescopes images in the FUV channel, while the other images in NUV and VIS channels via a beamsplitter. Images from the VIS channel are principally used for measuring drift, used in construction of images on the ground by shift and add, and to reconstruct absolute aspect of the images. Adequate baffling has been provided for reducing the scattered background from the Sun, earth albedo and other bright objects. The one-time opening mechanical cover on each telescope also works as a Sun-shield after deployment. We will present the overall (mechanical, optical and electrical) design of the payload.

We present the SVOM mission that the Chinese National Space Agency and the French Space Agency have decided to jointly implement. SVOM has been designed to detect, characterise and quickly localise gamma-ray bursts (GRBs) and other types of high-energy transients. For this task the spacecraft will carry two widefield high-energy instruments: ECLAIRs, a hard X-ray imager, and the Gamma-Ray Monitor, a broadband spectrometer. Upon localising a transient, SVOM will quickly slew towards the source and start deep followup observations with two narrow-field telescopes: the Micro-channel X-ray Telescope in X-rays and the Visible Telescope in the visible. The nearly anti-solar pointing of SVOM combined with the fast transmission of GRB positions to the ground in less than 1 minute, will facilitate the observations of SVOM transients by the largest ground based telescopes.

The Hard X-ray Modulation Telescope (HXMT) is China’s first astronomical satellite. On board HXMT there are three kinds of slat-collimated telescopes, the High Energy X-ray Telescope (HE, 20-250 keV, 5000 cm2), the Medium Energy X-ray Telescope (ME, 5-30 keV, 952 cm2), and the Low Energy X-ray Telescope (LE, 1-15 keV, 394cm2). The typical Field of View (FOV) of HXMT is 1° × 6° (FWHM), and it has other FOVs so as to measure the cosmic and the local particle induced X-ray backgrounds. The 3-σ continuum sensitivity of HXMT is about 0.5 mCrab (105s). HXMT will perform a broad band (1-250 keV) X-ray sky survey and do pointed observations of X-ray sources to study their broadband spectra and the multi-wavelength temporal variabilities. The planned launch date of HXMT is around 2014/2015. It will run in a low earth orbit with an inclination angle of 43°, and its designed lifetime is 4 years. Now HXMT is in the pre-flight model construction phase

The Gravity and Extreme Magnetism Small Explorer (GEMS) will realize its scientific objectives through high sensitivity linear X-ray polarization measurements in the 2-10 keV band. The GEMS X-ray polarimeters, based on the photoelectric effect, provide a strong polarization response with high quantum efficiency over a broad band-pass by a novel implementation of the time projection chamber (TPC). This paper will discuss the basic principles of the TPC polarimeter and describe the details of the mechanical and electrical design of the GEMS flight polarimeter. We will present performance measurements from two GEMS engineering test units in response to polarized and unpolarized X-rays and before and after thermal and vibration tests performed to demonstrate that the design is at a technology readiness level 6 (TRL-6).

In this paper we report on the status of eROSITA (extended ROentgen Survey with an Imaging Telescope Array). eROSITA is the core instrument on the Russian Spektrum-Roentgen-Gamma (SRG) mission which is currently scheduled for launch in 2014. It will perform an all-sky survey lasting four years, followed by a phase of three years for pointed observations. The instrument consists of seven identical Mirror Modules, each equipped with 54 Wolter-I shells with an outer diameter of 360 mm. This provides an effective area of ~1500 cm² at 1.5 keV and an on axis PSF HEW of 15 arcsec resulting in an effective angular resolution of 28 arcsec averaged over the field of view. In the focus of each mirror module, a fast frame-store pn-CCD provides a field of view of 1º in diameter. Meanwhile the telescope structure is completely assembled, more than 60% of all mirror shells are integrated, and almost all subsystems are qualified, tested, and within their specifications.

MPE will provide the X-ray Survey Telescope eROSITA for the Russian Spektrum-Roentgen-Gamma Mission. The mirror system consists of a compact bundle of seven co-aligned mirror modules with a focal length of 1600 mm and 54 nested mirror shells each. The 61 arcmin field-of-view (FoV) will yield a high grasp of about 1000 cm²deg² around 1 keV. An angular resolution of 15 arcsec HEW on-axis (resulting in an average angular resolution of ~26 arcsec HEW over the field-of-view and ~30 arcsec including all optical and spacecraft error contributions) will help distinguish point sources from extended emission of galaxy clusters which are relevant for cosmological studies. During a four year allsky survey eROSITA will generate a new rich database of X-ray sources. In a second phase of the mission eROSITA will also perform pointed observations.

After a mirror development program the integration of flight mirror modules started in early 2011. Currently, the manufacturing of flight modules is ongoing and some of the partially integrated ones have already been X-ray tested. Calibration of completed mirror modules will start end of 2012. Parallel to the X-ray mirrors we have developed an X-ray baffle to suppress stray light from single reflections. It consists of precisely shaped and welded concentric Invar foils which will be mounted on top of each mirror module and aligned by optical means.

We report on the design and the mirror development program including the X-ray baffle and present the latest results from X-ray measurements.

Spectrum Roentgen Gamma (SRG) is an X-ray astrophysical observatory, developed by Russia in collaboration with Germany. The mission will be launched in 2014 from Baikonur, by a Zenit rocket with a Fregat booster and placed in a 6-month-period halo orbit around L2. The scientific payload consists of two independent telescopes – a soft-x-ray survey instrument, eROSITA, being provided by Germany and a medium-x-ray-energy survey instrument ART-XC being developed by Russia. ART-XC will consist of seven independent, but co-aligned, telescope modules with seven corresponding cadmium-telluride focal plane detectors. Each will operate over the approximate energy range of 6−30 keV, with an angular resolution of <1′, a field of view of ~30' and an energy resolution about 10% at 14 keV. The NASA Marshall Space Flight Center (MSFC) will fabricate some of the mirror modules, to complement others fabricated by VNIIEF in Russia.

The Marshall Space Flight Center (MSFC) is developing x-ray mirror modules for the ART-XC instrument on board the Spectrum-Roentgen-Gamma Mission under a Reimbursable Agreement between NASA and the Russian Space Research Institute (IKI.) ART-XC will consist of seven co-aligned x-ray mirror modules with seven corresponding CdTe focal plane detectors. Currently, four of the modules are being fabricated by the Marshall Space Flight Center (MSFC.) Each MSFC module consist of 28 nested Ni/Co thin shells giving an effective area of 65 cm² at 8 keV, response out to 30 keV, and an angular resolution of 45 arcsec or better HPD. Delivery of these modules to the IKI is scheduled for summer 2013. We present a status of the ART x-ray modules development at the MSFC.

The Nuclear Spectroscopic Telescope Array (NuSTAR) launched in June 2012 carries the first focusing hard Xray (5 - 80 keV) telescope to orbit. The on-ground calibration was performed at the RaMCaF facility at Nevis, Columbia University. During the assembly of the telescopes, mechanical surface metrology provided surface maps of the reflecting surfaces. Several flight coated mirrors were brought to BNL for scattering measurements. The information from both sources is fed to a raytracing code that is tested against the on-ground calibration data. The code is subsequently used for predicting the imaging properties for X-ray sources at infinite distance.

The Nuclear Spectroscopic Telescope ARray (NuSTAR) was launched in June 2012 carrying the first focusing hard X-ray (5−80keV) optics to orbit. The multilayer coating was carried out at the Technical University of Denmark (DTU Space). In this article we introduce the NuSTAR multilayer reference database and its implementation in the NuSTAR optic response model. The database and its implementation is validated using on-ground effective area calibration data and used to estimate in-orbit performance.

The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will investigate the physics of the highenergy universe via a suite of four instruments, covering a very wide energy range, from 0.3 keV to 600 keV. These instruments include a high-resolution, high-throughput spectrometer sensitive over 0.3–12 keV with high spectral resolution of ΔE ≦ 7 eV, enabled by a micro-calorimeter array located in the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers covering 5–80 keV, located in the focal plane of multilayer-coated, focusing hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4–12 keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the 40–600 keV band. The simultaneous broad bandpass, coupled with high spectral resolution, will enable the pursuit of a wide variety of important science themes.

ASTRO-H is a Japanese X-ray astrophysics satellite under the development led by Japan and US. It will have two Soft X-ray Telescopes (SXTs), among other instruments, that are being developed by NASA's Goddard Space Flight Center. One is for an X-ray micro-calorimeter instrument and the other for an X-ray CCD camera, both covering the X-ray energy band below 15 keV. The SXT Engineering Model (EM) quadrant was successfully completed and has shown big improvements in the X-ray performance from Suzaku owing to number of changes made. The EM was tested at the Goddard 100-m X-ray beamline (diverging beam) and the ISAS/JAXA beamline (pencil beam scan). The angular resolution was found to be 1.1 arcmin at Goddard, while 1.27 arcmin at ISAS, and the effective area was 157 and 122 cm² at 1 and 6 keV, respectively. The discrepancy in the angular resolution can be explained by the difference of the measurement method, i.e. the diverging beam vs. the pencil beam scan. The development of the first Flight Model (FM) is underway. The first three quadrants are completed so far and show about 1 arcmin (HPD) angular resolution. We expect that the first FM SXT will have about 1 arcmin resolution, which will be completed in September, 2012.

Soft X-ray Imager (SXI) is a CCD camera onboard the ASTRO-H satellite which is scheduled to be launched in 2014. The SXI camera contains four CCD chips, each with an imaging area of 31mm× 31 mm, arrayed in mosaic, which cover the whole FOV area of 38' × 38'. The SXI CCDs are a P-channel back-illuminated (BI) type with a depletion layer thickness of 200 μm. High QE of 77% at 10 keV expected for this device is an advantage to cover an overlapping energy band with the Hard X-ray Imager (HXI) onboard ASTRO-H. Verification with engineering model of the SXI has been performed since 2011. Flight model design was fixed and its fabrication has started in 2012.

ASTRO-H is an international X-ray mission of ISAS/JAXA, which will be launched in 2014. One of the main characteristics of ASTRO-H is imaging spectroscopy in the hard X-ray band above 10 keV. ASTRO-H will carry two identical Hard X-ray telescopes (HXTs), whose mirror surfaces are coated with Pt/C depth-graded multilayers to enhance hard X-ray effective area up to 80 keV.

HXT was designed based on the telescope on board the SUMIT balloon borne experiment. After feasibility study of the HXT design, the FM design has been deteremined. Mass production of the mirror shells at Nagoya University has been going on since August 2010, and production of mirror shells for HXT-1 was completed in March 2012. After the integation of X-ray mirrors for HXT-1, we measured hard X-ray performance of selected mirror shells for HXT-1 at a synchrotron radiation facility, SPring-8 beamline BL20B2. We will perform environment tests and ground calibarations at SPring-8 for HXT-1. In HXT-2, foil production is going on.

The Hard X-ray Imager (HXI) is one of the four detectors on board the ASTRO-H mission (6th Japanese X-ray satellite), which is scheduled to be launched in 2014. Using the hybrid structure composed of double-sided silicon strip detectors and a cadmium telluride double-sided strip detector, both with a high spatial resolution of 250 μm. Combined with the hard X-ray telescope (HXT), it consists a hard X-ray imaging spectroscopic instrument covering the energy range from 5 to 80 keV with an effective area of <300 cm² in total at 30 keV. An energy resolution of 1–2 keV (FWHM) and lower threshold of 5 keV are both achieved with using a low noise front-end ASICs. In addition, the thick BGO active shields surrounding the main detector package is a heritage of the successful performance of the Hard X-ray Detector on board the Suzaku satellite. This feature enables the instrument to achieve an extremely good reduction of background caused by cosmic-ray particles, cosmic X-ray background, and in-orbit radiation activation. In this paper, we present the detector concept, design, latest results of the detector development, and the current status of the hardware.

ASTRO-H is the next generation JAXA X-ray satellite, intended to carry instruments with broad energy coverage and exquisite energy resolution. The Soft Gamma-ray Detector (SGD) is one of ASTRO-H instruments and will feature wide energy band (60–600 keV) at a background level 10 times better than the current instruments on orbit. The SGD is complimentary to ASTRO-H’s Hard X-ray Imager covering the energy range of 5–80 keV. The SGD achieves low background by combining a Compton camera scheme with a narrow field-of-view active shield where Compton kinematics is utilized to reject backgrounds. The Compton camera in the SGD is realized as a hybrid semiconductor detector system which consists of silicon and CdTe (cadmium telluride) sensors. Good energy resolution is afforded by semiconductor sensors, and it results in good background rejection capability due to better constraints on Compton kinematics. Utilization of Compton kinematics also makes the SGD sensitive to the gamma-ray polarization, opening up a new window to study properties of gamma-ray emission processes. In this paper, we will present the detailed design of the SGD and the results of the final prototype developments and evaluations. Moreover, we will also present expected performance based on the measurements with prototypes.

ATHENA (Advanced Telescope for High Energy Astrophysics) was an L class mission candidate within the science programme Cosmic Vision 2015-2025 of the European Space Agency, with a planned launch by 2022. ATHENA was conceived as an ESA-led project, open to the possibility of focused contributions from JAXA and NASA. By allowing astrophysical observations between 100 eV and 10 keV, it would represent the new generation X-ray observatory, following the XMM-Newton, Astro-H and Chandra heritage. The main scientific objectives of ATHENA include the study of large scale structures, the evolution of black holes, strong gravity effects, neutron star structure as well as investigations into dark matter. The ATHENA mission concept would be based on focal length of 12m achieved via a rigid metering tube and a twoaperture, x-ray telescope. Two identical x-ray mirrors would illuminate fixed focal plane instruments: a cryogenic imaging spectrometer (XMS) and a wide field imager (WFI). The S/C is designed to be fully compatible with Ariane 5 ECA. The observatory would operate at SE-L2, with a nominal lifetime of 5 yr. This paper provides a summary of the reformulation activities, completed in December 2011. An overview of the spacecraft design and of the payload is provided, including both telescope and instruments. Following the ESA Science Programme Committee decision on the L1 mission in May 2012, ATHENA was not selected to enter Definition Phase.

Silicon Pore Optics (SPO) is a lightweight high performance X-ray optics technology being developed in Europe, driven by applications in observatory class high energy astrophysics missions. An example of such application is the former ESA science mission candidate ATHENA (Advanced Telescope for High Energy Astrophysics), which uses the SPO technology for its two telescopes, in order to provide an effective area exceeding 1 m² at 1 keV, and 0.5 m² at 6 keV, featuring an angular resolution of 10” or better [1 to 24].

This paper reports on the development activities led by ESA, and the status of the SPO technology. The technology development programme has succeeded in maturing the SPO further and achieving important milestones, in each of the main activity streams: environmental compatibility, industrial production and optical performance. In order to accurately characterise the increasing performance of this innovative optical technology, the associated X-ray test facilities and beam-lines have been refined and upgraded.

The Advanced Telescope for High ENergy Astrophysics (ATHENA) is one of the three candidates that competed for the first large-class mission (L1) in ESA’s Cosmic Vision 2015-2025 programme, with a launch planned by 2022 and is the result of the IXO reformulation activities. ATHENA is an ESA-led project and is conceived as the next generation X-ray observatory. It is meant to address fundamental questions about accretion around black-holes, reveal the physics underpinning cosmic feedback, trace the large scale structure of baryons in galaxy clusters and the cosmic as well as a large number of astrophysics and fundamental physics phenomena. The observatory consists of two identical mirrors each illuminating a fixed focal plane instrument, providing collectively 1 m² effective area at 1 keV. The reference payload consists of a medium resolution wide field imager (WFI) and a high resolution X-ray micro-calorimeter spectrometer (XMS). The WFI is based on a monolithic Si DepFET array providing imaging over a 24 × 24 arcmin² field of view and a good PSF oversampling. The sensor will measure X-rays in the range 0.1–15 keV and provides near Fano limited energy resolution (150eV at 6keV). The XMS is based on a micro-calorimeter array operating at its transition temperature of ~100mK and provides <3eV resolution. The detector array consists of 32 × 32 pixels covering a 2.3 × 2.3 arcmin² field of view, co-aligned with the WFI. This paper summarizes the results of the reformulation exercise and provides details on the payload complement and its accommodation on the spacecraft. Following the ESA Science Programme Committee decision on the L1 mission in May 2012, ATHENA was not selected to enter Definition Phase.

One of the instruments on the Advanced Telescope for High-Energy Astrophysics (Athena) which was one of the three missions under study as one of the L-class missions of ESA, is the X-ray Microcalorimeter Spectrometer (XMS). This instrument, which will provide high-spectral resolution images, is based on X-ray micro-calorimeters with Transition Edge Sensor (TES) and absorbers that consist of metal and semi-metal layers and a multiplexed SQUID readout. The array (32 x 32 pixels) provides an energy resolution of < 3 eV. Due to the large collection area of the Athena optics, the XMS instrument must be capable of processing high counting rates, while maintaining the spectral resolution and a low deadtime. In addition, an anti-coincidence detector is required to suppress the particle-induced background. Compared to the requirements for the same instrument on IXO, the performance requirements have been relaxed to fit into the much more restricted boundary conditions of Athena. In this paper we illustrate some of the science achievable with the instrument. We describe the results of design studies for the focal plane assembly and the cooling systems. Also, the system and its required spacecraft resources will be given.

The LOFT mission concept is one of four candidates selected by ESA for the M3 launch opportunity as Medium Size missions of the Cosmic Vision programme. The launch window is currently planned for between 2022 and 2024. LOFT is designed to exploit the diagnostics of rapid X-ray flux and spectral variability that directly probe the motion of matter down to distances very close to black holes and neutron stars, as well as the physical state of ultradense matter. These primary science goals will be addressed by a payload composed of a Large Area Detector (LAD) and a Wide Field Monitor (WFM). The LAD is a collimated (<1 degree field of view) experiment operating in the energy range 2-50 keV, with a 10 m² peak effective area and an energy resolution of 260 eV at 6 keV. The WFM will operate in the same energy range as the LAD, enabling simultaneous monitoring of a few-steradian wide field of view, with an angular resolution of <5 arcmin. The LAD and WFM experiments will allow us to investigate variability from submillisecond QPO’s to yearlong transient outbursts. In this paper we report the current status of the project.

LOFT (Large Observatory For x-ray Timing) is one of four candidates for the M3 slot (launch in 2024, with the option of a launch in 2022) of ESAs Cosmic Vision 2015 – 2025 Plan, and as such it is currently undergoing an initial assessment phase lasting one year. The objective of the assessment phase is to provide the information required to enable the down selection process, in particular: the space segment definition for meeting the assigned science objectives; consideration of and initial definition of the implementation schedule; an estimate of the mission Cost at Completion (CaC); an evaluation of the technology readiness evaluation and risk assessment. The assessment phase is divided into two interleaved components: (i) A payload assessment study, performed by teams funded by member states, which is primarily intended for design, definition and programmatic/cost evaluation of the payload, and (ii) A system industrial study, which has essentially the same objectives for the space segment of the mission. This paper provides an overview of the status of the LOFT assessment phase, both for payload and platform. The initial focus is on the payload design status, providing the reader with an understanding of the main features of the design. Then the space segment assessment study status is presented, with an overview of the principal challenges presented by the LOFT payload and mission requirements, and a presentation of the expected solutions. Overall the mission is expected to enable cutting-edge science, is technically feasible, and should remain within the required CaC for an M3 candidate.

The Large Observatory for X-ray Timing (LOFT) is one of the four candidate ESA M3 missions considered for launch in the 2022 timeframe. It is specifically designed to perform fast X-ray timing and probe the status of the matter near black holes and neutron stars. The LOFT scientific payload is composed of a Large Area Detector (LAD) and a Wide Field Monitor (WFM). The LAD is a 10 m²-class pointed instrument with 20 times the collecting area of the best past timing missions (such as RXTE) over the 2-30 keV range, which holds the capability to revolutionize studies of X-ray variability down to the millisecond time scales. Its ground-breaking characteristic is a low mass per unit surface, enabling an effective area of ~10 m² (@10 keV) at a reasonable weight. The development of such large but light experiment, with low mass and power per unit area, is now made possible by the recent advancements in the field of large-area silicon detectors - able to time tag an X-ray photon with an accuracy <10 μs and an energy resolution of ~260 eV at 6 keV - and capillary-plate X-ray collimators. In this paper, we will summarize the characteristics of the LAD instrument and give an overview of its capabilities.

LOFT (Large Observatory For x-ray Timing) is one of the four missions selected in 2011 for assessment study for the ESA M3 mission in the Cosmic Vision program, expected to be launched in 2024. The LOFT mission will carry two instruments with their prime sensitivity in the 2-30 keV range: a 10 m² class large area detector (LAD) with a <1° collimated field of view and a wide field monitor (WFM) instrument based on the coded mask principle, providing coverage of more than 1/3 of the sky. The LAD will provide an effective area ~20 times larger than any previous mission and will by timing studies be able to address fundamental questions about strong gravity in the vicinity of black holes and the equation of state of nuclear matter in neutron stars. The prime goal of the WFM will be to detect transient sources to be observed by the LAD. However, with its wide field of view and good energy resolution of <300 eV, the WFM will be an excellent monitoring instrument to study long term variability of many classes of X-ray sources. The sensitivity of the WFM will be 2.1 mCrab in a one day observation, and 270 mCrab in 3s in observations of in the crowded field of the Galactic Center. The high duty cycle of the instrument will make it an ideal detector of fast transient phenomena, like X-ray bursters, soft gamma repeaters, terrestrial gamma flashes, and not least provide unique capabilities in the study of gamma ray bursts. A dedicated burst alert system will enable the distribution to the community of ~100 gamma ray burst positions per year with a ~1 arcmin location accuracy within 30 s of the burst. This paper provides an overview of the design, configuration, and capabilities of the LOFT WFM instrument.

The main objective of the Wide Field Monitor (WFM) on the LOFT mission is to provide unambiguous detection of the high-energy sources in a large field of view, in order to support science operations of the LOFT primary instrument, the LAD. The monitor will also provide by itself a large number of results on the timing and spectral behavior of hundreds of galactic compact objects, Active Galactic Nuclei and Gamma-Ray Bursts. The WFM is based on the coded aperture concept where a position sensitive detector records the shadow of a mask projected by the celestial sources. The proposed WFM detector plane, based on Double Sided micro-Strip Silicon Detectors (DSSD), will allow proper 2-dimensional recording of the projected shadows. Indeed the positioning of the photon interaction in the detector with equivalent fine resolution in both directions insures the best imaging capability compatible with the allocated budgets for this telescope on LOFT. We will describe here the overall configuration of this 2D-WFM and the design and characteristics of the DSSD detector plane including its imaging and spectral performances. We will also present a number of simulated results discussing the advantages that this configuration offers to LOFT. A DSSD-based WFM will in particular reduce significantly the source confusion experienced by the WFM in crowded regions of the sky like the Galactic Center and will in general increase the observatory science capability of the mission.

Soft protons can be a major source of degradation of the performances of instrumentation in space, in particular for CCDs. It was learned from the experience of Chandra and XMM-Newton that they can be funneled through the mirrorshells of an X-ray telescope down to the focal plane and hit detectors. This seems the favoured mechanism, since in general a detector placed at the focal plane is completely shielded from environmental soft protons except that in correspondance of the aperture field of view. However, the bombardment of high-energy cosmic rays can induce spallation reactions in the shield itself and other materials present at the focal plane. These processes generate secondary hadrons at softer energy, which can escape the target and reach the detectors. The products of spallation are mainly protons and neutrons. Neutrons can also have an impact on the performances of a Silicon-based detector. We study the production of secondary hadrons in the case of the pn-CCDs aboard eROSITA and the DEPFET Wide Field Imager aboard ATHENA, calculate expected doses over the missions duration and discuss possible effects on these detectors.

Imaging detectors for wavelengths between 10 nm and 105 nm generally rely on microchannel plates (MCPs) to provide photon detection (via the photo-electric effect) and charge amplification. This is because silicon-based detectors (CCD or APS) have near zero quantum detection efficiency (QDE) over this wavelength regime. Combining a MCP based intensifier tube with a silicon detector creates a detector system that can be tuned to the wavelength regime of interest for a variety of applications. Intensified detectors are used in a variety of scientific (e.g. Solar Physics) and commercial applications (spectroscopic test instrumentation, night vision goggles, low intensity cameras, etc.). Building an intensified detector requires the mastery of a variety of technologies involved in integrating and testing of these detector systems.

We report on an internally funded development program within the Southwest Research Institute to architect, design, integrate, and test intensified imaging detectors for space-based applications. Through a rigorous hardware program the effort is developing and maturing the technologies necessary to build and test a large format (2k × 2k) UV intensified CCD detector. The intensified CCD is designed around a commercially available CCD that is optically coupled to a UV Intensifier Tube from Sensor Sciences, LLC. The program aims to demonstrate, through hardware validation, the ability to architect and execute the integration steps necessary to produce detector systems suitable for space-based applications.

Recent technological innovations make it feasible to construct efficient hard x-ray telescopes for space-based astronomical missions. Focusing optics are capable of improving the sensitivity in the energy range above 10 keV by orders of magnitude compared to previously used instruments. The last decade has seen focusing optics developed for balloon experiments and they are implemented in approved space missions such as the Nuclear Spectroscopic Telescope Array (NuSTAR). The full characterization of x-ray optics for astrophysical missions, including measurement of the point spread function (PSF) as well as scattering and reflectivity properties of substrate coatings, requires a large area detector with very high spatial resolution and sensitivity, photon counting and energy discriminating capability. Novel back-thinned Electron Multiplying Charge-Coupled Devices (EMCCDs) are suitable detectors for ground-based calibrations if combined with a scintillating material. This optical coupling of the EMCCD chip to a microcolumnar CsI(Tl) scintillator can be achieved via a fiberoptic taper. Not only does this detector system exhibit low noise and high spatial resolution inherent to CCDs, but the EMCCD is also able to handle high frame rates. Additionally, thick CsI(Tl) yields high detection efficiency for x-rays. In this paper, we discuss the advantages of using an EMCCD to calibrate hard x-ray optics. We will illustrate the promising features of this detector solution using examples of data obtained during the ground calibration of the NuSTAR telescopes performed at Columbia University during 2010/2011. Finally, we give an outlook on latest development and optimizations.

Future space-based X-ray observatories will not only have increased sensitivity and energy resolution but will provide astronomers with high time resolution in the order of microseconds. The detection of millions of single photons per second with their precise energy and their time of arrival will produce unprecedented data rates that cannot be downlinked to Earth in their full extend due to telemetry limitations. We present the study of a very fast, lossless, on-board data compression implemented in an FPGA-based LEON3 microprocessor. We conclude with performance estimates done with a prototype board developed for the High Time Resolution Spectrometer (HTRS) on board the International X-ray Observatory (IXO). We also discuss a possible application of the Data Processing Unit (DPU) for the future X-ray mission Large Observatory for X-ray Timing (LOFT).

The World Space Observatory - Ultraviolet (WSO-UV) will be the only space telescope for the ultraviolet wavelength range between 102 and 310 nm during the next decade. It is a multinational project under Russian leadership with contributions from Ukraine and Spain. Its main instrument, the WSO-UV Spectrographs (WUVS), was designed by IAAT in collaboration with the Leibniz Institut für Analytische Wissenschaften, Berlin. We are developing the corresponding microchannel plate detectors using new combinations of materials for the photocathode as well as a 64 by 64 cross strip anode for event position determination. Charge pre-amplification is performed by the Beetle chip designed at the ASIC laboratory of the MPIK for LHCb at CERN. It has 128 pre-amplifiers on one die and provides the analog output in a four-fold serial stream. This stream is digitized by four ADCs and processed in a Microsemi RTAX FPGA. Processed data are sent to the instrument control unit via a SpaceWire interface. This concept results in one order of magnitude reduced power consumption in comparison to the use of conventional pre-amplifiers as well as a reduced volume, weight and complexity of the readout electronics. This paper presents the architecture of the electronics and details of the FPGA design as well as an estimation of the performance of our setup.

Calibration of optical systems is a fundamental step in the development of a space instrumentation. We have built a new cleanroom environment, divided in different areas characterized by a different level of contamination control. A vacuum chamber (a tube of 80 cm diameter, and 2 m length), able to accommodate optical components as well as whole instruments, is interfaced with a ISO6 area, allowing the handling of the instrumentation in a clean environment. The vacuum system is dimensioned to reach 10^-7 mbar pressure in the chamber. Inside, a two axis platform allows the rotation of the instrument with respect to the incident collimating beam, in order to test the response of the instrument to light coming from different points of the field of view. A monochromator coupled with different sources provides radiation in the 40-350 nm spectral range, while a parabolic mirror is used as a collimator. As source, different spectral lamps can be used to generate emission lines, while a Xe lamp can be used to have continuum spectrum. An high brilliant hollow cathode lamp has been fabricated by the group to generate extreme ultraviolet radiation. Different calibrated detectors and other completing optical components are available.

The Swift Gamma-ray Burst (GRB) observatory responds to GRB triggers with optical observations in ~ 100 s, butcannot respond faster than ~ 60 s. While some rapid-response ground-based telescopes have responded quickly, thenumber of sub-60 s detections remains small. In 2013 June, the Ultra-Fast Flash Observatory-Pathfinder is expected tobe launched on the Lomonosov spacecraft to investigate early optical GRB emission. Though possessing uniquecapability for optical rapid-response, this pathfinder mission is necessarily limited in sensitivity and event rate; here wediscuss the next generation of rapid-response space observatory instruments. We list science topics motivating ourinstruments, those that require rapid optical-IR GRB response, including: A survey of GRB rise shapes/times,measurements of optical bulk Lorentz factors, investigation of magnetic dominated (vs. non-magnetic) jet models,internal vs. external shock origin of prompt optical emission, the use of GRBs for cosmology, and dust evaporation inthe GRB environment. We also address the impacts of the characteristics of GRB observing on our instrument andobservatory design. We describe our instrument designs and choices for a next generation space observatory as a secondinstrument on a low-earth orbit spacecraft, with a 120 kg instrument mass budget. Restricted to relatively modest mass,power, and launch resources, we find that a coded mask X-ray camera with 1024 cm² of detector area could rapidlylocate about 64 GRB triggers/year. Responding to the locations from the X-ray camera, a 30 cm aperture telescope witha beam-steering system for rapid (~ 1 s) response and a near-IR camera should detect ~ 29 GRB, given Swift GRBproperties. The additional optical camera would permit the measurement of a broadband optical-IR slope, allowingbetter characterization of the emission, and dynamic measurement of dust extinction at the source, for the first time.

The Slewing Mirror Telescope (SMT) is a key telescope of Ultra-Fast Flash Observatory (UFFO) space project to explore the first sub-minute or sub-seconds early photons from the Gamma Ray Bursts (GRBs) afterglows. As the realization of UFFO, 20kg of UFFO-Pathfinder (UFFO-P) is going to be on board the Russian Lomonosov satellite in November 2012 by Soyuz-2 rocket. Once the UFFO Burst Alert & Trigger Telescope (UBAT) detects the GRBs, Slewing mirror (SM) will slew to bring new GRB into the SMT’s field of view rather than slewing the entire spacecraft. SMT can give a UV/Optical counterpart position rather moderated 4arcsec accuracy. However it will provide a important understanding of the GRB mechanism by measuring the sub-minute optical photons from GRBs. SMT can respond to the trigger over 35 degree x 35 degree wide field of view within 1 sec by using Slewing Mirror Stage (SMS). SMT is the reflecting telescope with 10cm Ritchey-Chretien type and 256 x 256 pixilated Intensified Charge-Coupled Device (ICCD). In this paper, we discuss the overall design of UFFO-P SMT instrument and payloads development status.

Since the launch of the SWIFT, Gamma-Ray Bursts (GRBs) science has been much progressed. Especially supporting many measurements of GRB events and sharing them with other telescopes by the Gamma-ray Coordinate Network (GCN) have resulted the richness of GRB events, however, only a few of GRB events have been measured within a minute after the gamma ray signal. This lack of sub-minute data limits the study for the characteristics of the UV-optical light curve of the short-hard type GRB and the fast-rising GRB. Therefore, we have developed the telescope named the Ultra-Fast Flash Observatory (UFFO) Pathfinder, to take the sub-minute data for the early photons from GRB. The UFFO Pathfinder has a coded-mask X-ray camera to search the GRB location by the UBAT trigger algorithm. To determine the direction of GRB as soon as possible it requires the fast processing. We have ultimately implemented all algorithms in field programmable gate arrays (FPGA) without microprocessor. Although FPGA, when compared with microprocessor, is generally estimated to support the fast processing rather than the complex processing, we have developed the implementation to overcome the disadvantage and to maximize the advantage. That is to measure the location as accurate as possible and to determine the location within the sub-second timescale. In the particular case for a accuracy of the X-ray trigger, it requires special information from the satellite based on the UFFO central control system. We present the implementation of the UBAT trigger algorithm as well as the readout system of the UFFO Pathfinder.

The Ultra Fast Flash Observatory pathfinder (UFFO-p) is a telescope system designed for the detection of the prompt optical/UV photons from Gamma-Ray Bursts (GRBs), and it will be launched onboard the Lomonosov spacecraft in 2012. The UFFO-p consists of two instruments: the UFFO Burst Alert and Trigger telescope (UBAT) for the detection and location of GRBs, and the Slewing Mirror Telescope (SMT) for measurement of the UV/optical afterglow. The UBAT isa coded-mask aperture X-ray camera with a wide field of view (FOV) of 1.8 sr. The detector module consists of the YSO(Yttrium Oxyorthosilicate) scintillator crystal array, a grid of 36 multi-anode photomultipliers (MAPMTs), and analog and digital readout electronics. When the γ /X-ray photons hit the YSO scintillator crystal array, it produces UV photons by scintillation in proportion to the energy of the incident γ /X-ray photons. The UBAT detects X-ray source of GRB inthe 5 ~ 100 keV energy range, localizes the GRB within 10 arcmin, and sends the SMT this information as well as drift correction in real time. All the process is controlled by a Field Programmable Gates Arrays (FPGA) to reduce the processing time. We are in the final stages of the development and expect to deliver the instrument for the integration with the spacecraft. In what follows we present the design, fabrication and performance test of the UBAT.

ISSIS is the Imaging and Slitless Spectroscopy Instrument for the World Space Observatory - Ultraviolet (WSO-UV), a 170 cm space telescope to be launched in late 2015. ISSIS is a multipurpose instrument designed to carry out high resolution and high sensitivity imaging and slitless spectroscopy in the ultraviolet range. ISSIS has two acquisition channels: the Far Ultraviolet Channel (FUV) covering the 1150-1750 Å wavelength range and the Near Ultraviolet Channel (NUV) in the 1850-3200 Å range. Both channels are equipped with Multi Channel Plate detectors to guarantee high sensitivity and high rejection of lower energy radiation. ISSIS will be the first UV imager into a high altitude Earth orbit and it will provide unique information on star formation, accretion physics, astronomical engines and planets.

The spectrographs of WSO-UV cover the wavelength range of 102 - 310 nm. The essential requirements for the associated detectors are high quantum effciency, solar blindness, and single photon detection. To achieve this, we develop a microchannel plate detector in a sealed tube. We plan to use cesium activated gallium nitride as semitransparent photocathode, a stack of two microchannel plates and a cross strip anode with advanced readout electronics. Challenges are the degradation of the photocathode under atmospheric conditions and the sealing process. We present the detector concept, details of the transfer and sealing processes under UHV, and the current status.

The extreme ultraviolet (EUV) telescope EXCEED (Extreme Ultraviolet Spectroscope for Exospheric Dynamics) onboard the Japan's small satellite SPRINT-A will be launched in August 2013. The EXCEED instrument will observe tenuous gases and plasmas around the planets in the solar system (e.g., Mercury, Venus, Mars, Jupiter, and Saturn). The EXCEED instrument is designed to have a spectral range of 60-145 nm with a spectral resolution of 0.4-1.0 nm. The instrument has a field of view of 400” x 140” (maximum), and the attitude fluctuations are stabilized within ±5". The optics of the instrument consists of an entrance mirror with a diameter of 200 mm, three types of slits, two types of filters, a laminar type grating, and a 5-stage microchannel plate assembly with a resistive anode encoder. In this paper, we report the general mission overview, the instrumentations, and the results of ground calibrations.

General approaches to the solution are shown on the example of one of the alternative variants of UV long-slit spectrometer. It is suggested using concave aberration-corrected holographic diffraction grating in FUV spectral range (102 – 175 nm). In NUV spectral range (175 – 310 nm), where mirror coating reflecting factor is higher, it is suggested using a beam of zero order of this grating with subsequent spectral decomposition performed with additional grating. It is known that diffractive grating efficiency depends on the form of grooves profile, in the first approximation step profile echelett grating fits quite well for this task.

Scattered solar and collisionally stimulated H Ly-α emission is a proven diagnostic for the study of the Sun, comets, the interplanetary medium, planet atmospheres, and corona. Here we discuss the construction and testing of a narrow bandpass instrument designed to observe H Ly-α emission at a resolving power of R~100,000 from targets with an angular extent of ≤½ degree. The instrument is an all-reflective form of the spatial heterodyne spectrometer (SHS), a self-scanning Fourier Transform Spectrometer. It will be incorporated into the focal plane of a suborbital telescope that is scheduled for a March 2013 launch. Initial alignment and vibrational testing was performed with the instrument aligned to a visible analog line. The results showed alignment stability under vibration, but revealed several unacceptable resonances that have been corrected in the mechanical design.

In the context of the LAUE project devoted to build a long focal length focusing optics for soft gamma-ray astronomy (70/100 keV to <>600 keV), we present results of simulation of a Laue lens, based on bent crystals in different assembling configurations (quasi-mosaic and reflection-like geometries). The main aim is to significantly overcome the sensitivity limits of the current generation of gamma-ray telescopes and improve the imaging capability.

In the context of the LAUE project devoted to build a long focal-length focusing optics for soft γ–ray astronomy (80 – 600 keV), we present the results of reflectivity measurements of bent crystals in different configurations, obtained by bending perfect or mosaic flat crystals. We also compare these results with those obtained using flat crystals. The measurements were performed using the Kα line of the Tungsten anode of the X–ray tube in the LARIX facility at the University of Ferrara. These results are finalized to select the best materials and to optimize the thickness of the crystal tiles that will be used for building a Laue lens petal which is a part of an entire Laue lens, with 20 m focal length and 100–300 keV passband. The final goal of the LAUE project is to overcome, by at least 2 orders of magnitude, the sensitivity limits of the current generation of γ–ray telescopes, and to improve the current γ–ray imaging capability.

For fabrication of crystals with curved diffracting planes, several techniques have been worked out. Amongst curved crystals, special interest is given to those that are being bent due to internal forces. Surface grooving is proposed as an efficient method to reproducibly obtain self-standing bent crystals. Silicon or germanium plates can be plastically deformed by grooving one of their major surfaces with very good control of the curvature. We present a systematic experimental study and a model based on the theory of elasticity. The technique enables the fabrication, in a very reproducible fashion, of curved crystals for the realization of an high-efficiency hard X-ray concentrator (Laue lens).

A stacking of plate-like curved crystals is proposed as an optical element for realization of a highly efficient Laue lens in astrophysics. Si mono-crystal plates have been bent by surface grooving and positioned one over the other to form a stack. Reciprocal alignment of the curved diffracting planes in the stack has been investigated by hard x-ray diffractometry using a polychromatic and divergent beam. The stack exhibited a single and well-defined focal spot under x-ray diffraction, highlighting that the plates are sufficiently aligned to behave as they were a single crystal. The curvature of the plates in the stack is self-standing and can be highly controlled by adjusting the experimental parameters of grooving. Thanks to the stacking, it would be possible to realize optical elements with arbitrarily large size. This achievement opens up important implications toward the realization of satellite-borne experiments in astrophysics or instruments for nuclear medicine with superior resolution. Surface grooving is easy, cheap, highly reproducible and has been established for Si and Ge, highlighting very high diffraction efficiency over a broad range of energies up to 700 keV, peaking 95% at 150 keV for Si.

Quasi-mosaicity can be used to fabricate self-standing curved crystals with two curvatures of different crystalline planes. Indeed, a primary curvature imparted to a crystal results in quasi-mosaic curvature of a different plane direction. We show that, since the size of the focal spot of the photons diffracted by a crystal can be controlled by the quasi-mosaic curvature, quasi-mosaic crystals allow focusing with very high resolution. A Laue lens, exploiting quasi-mosaic effect, has been simulated and main results are shown. Self-standing quasi-mosaic crystals can be fabricated through several techniques, such as film deposition or surface grooving method.

In the last few years we have been working on feasibility studies of future instruments in the gamma-ray range, from several keV up to a few MeV. The innovative concept of focusing gamma-ray telescopes in this energy range, should allow reaching unprecedented sensitivities and angular resolution, thanks to the decoupling of collecting area and detector volume. High sensitivities are essential to perform detailed studies of cosmic explosions and cosmic accelerators, e.g., Supernovae, Classical Novae, Supernova Remnants (SNRs), Gamma-Ray Bursts (GRBs), Pulsars, Active Galactic Nuclei (AGN). In order to achieve the needed performance, a gamma-ray imaging detector with mm spatial resolution and large enough efficiency is required. In order to fulfill the combined requirement of high detection efficiency with good spatial and energy resolution, an initial prototype of a gamma-ray imaging detector based on CdTe pixel detectors is being developed. It consists of a stack of several layers of CdTe detectors with increasing thickness, in order to enhance the gamma-ray absorption in the Compton regime. A CdTe module detector lies in a 11 x 11 pixel detector with a pixel pitch of 1mm attached to the readout chip. Each pixel is bump bonded to a fan-out board made of alumina (Al₂O₃) substrate and routed to the corresponding input channel of the readout ASIC to measure pixel position and pulse height for each incident gamma-ray photon. We will report the main features of the gamma-ray imaging detector performance such as the energy resolution for a set of radiation sources at different operating temperatures.

The Advanced Energetic Pair Telescope (AdEPT) will explore the universe in the medium-energy range from about 5 MeV to greater than 200 MeV via gamma-ray pair production. AdEPT will provide high angular resolution observations and for the first time high polarization sensitivity over this essentially unexplored energy range. The NASA/GSFC quasi-monoenergetic 6 MeV Gamma Facility was built to characterize detector’s response of planetary science and astrophysics instrumentation to be done in house. It will provide the ability to study pair production imaging of the AdEPT pair telescope at the difficult low end of its energy range. There is no natural radioactive isotope that provides a gamma ray with energy above the 2.614 MeV line of ²²⁸Th. The quasi-monoenergetic 6 MeV gamma-ray source provides a calibration point at significantly higher energy and is thus necessary to the design and testing of astrophysics and planetary neutron/gamma-ray instruments. This paper presents the mechanical design of the facility and the measured activity of the source.

The Volcano Sierra Negra in Puebla, Mexico was selected to host HAWC (High Altitude Water Cherenkov), a unique observatory of wide field of view (2sr) capable of observing the sky continuously at energies up to 100 TeV. HAWC is proposed as an array of 300 Cherenkov detectors consisting of 5m deep and 7.3 m diameter steel container containing 200,000 liters of purified water, each container with 4 Hamamatsu PMTs. The first construction stage of 7 tanks, VAMOS, was finished this year and it is continuously operating. In this work, the Cherenkov detectors and the electronics of VAMOS are described.

HAWC (High Altitude Water Cherenkov), is a gamma ray (γ) large aperture observatory with high sensitivity that will be able to continuously monitor the sky for transient sources of photons with energies between 100 GeV and 100 TeV. HAWC is under construction in Sierra Negra, Puebla, Mexico, which is located at a high altitude of 4100m. HAWC will be an array of 300 Cherenkov detectors each one with 200,000 liters of highly pure water. The sensitivity of the instrument depends strongly on the water quality. We present the design and construction of the HAWC water quality monitoring system. We seek monitor the transparency in violet-blue range to achieve and maintain the required water transparency quality in each detector. The system is robust and user friendly. The measurements are reproducible. Also we present some results from the monitoring the water from the VAMOS detector tanks and of the filtering system.

Gamma-Ray Imaging, Polarimetry and Spectroscopy (GRIPS) is a proposed space mission for gamma-ray astrophysics. It will be capable of imaging gamma-rays via Compton scattering and pair production in the energy range from ~200 keV up to ~50MeV. GRIPS will address fundamental astrophysical questions through observations of energetic gamma-ray phenomena such as gamma-ray bursts, blazars and supernovae in this unique energy window. The Medium-Energy Gamma-ray Astronomy library (MEGAlib) is an open-source object-oriented software library designed to simulate and analyse data from low-to-medium-energy gamma-ray telescopes, especially Compton telescopes such as GRIPS. The library comprises all necessary data analysis steps from initial simulations through to event reconstruction and image reconstruction. Simulations are being carried out to optimize the sensitivity of GRIPS to gamma-ray sources using MEGAlib and the results are presented here. GRIPS will offer an improvement in sensitivity in its operational energy range by a factor of ~40 compared with previous missions.

The supporting instrument on board the Fermi Gamma-ray Space Telescope, the Gamma-ray Burst Monitor (GBM) is a wide-field gamma-ray monitor composed of 14 individual scintillation detectors, with a field of view which encompasses the entire unocculted sky. Primarily designed as transient monitors, the conventional method for background determination with GBM-like instruments is to time interpolate intervals before and after the source as a polynomial. This is generally sufficient for sharp impulsive phenomena such as Gamma-Ray Bursts (GRBs) which are characterised by impulsive peaks with sharp rises, often highly structured, and easily distinguishable against instrumental backgrounds. However, smoother long lived emission, such as observed in solar flares and some GRBs, would be difficult to detect in a background-limited instrument using this method. We present here a description of a technique which uses the rates from adjacent days when the satellite has approximately the same geographical footprint to distinguish low-level emission from the instrumental background. We present results from the application of this technique to GBM data and discuss the implementation of it in a generalised background limited detector in a non-equatorial orbit.

Experimental multilayer reflectance data on flight mirrors and witnesses for three extreme ultraviolet (EUV) channels of the Atmospheric Imaging Assembly (AIA) instrument aboard NASA’s Solar Dynamics Observatory are presented and compared to theoretical models. The relevance of these results to the performance of the AIA instrument is discussed.

This paper discusses the design of the IRIS Small Explorer (SMEX) Cassegrain telescope, as well as its intended and measured performance. Lockheed Martin, along with SAO, Montana State University, and Stanford University are developing the IRIS instrument for a mission to examine the solar spectra in two bands, one centered on 1369 Å, and the other centered on 2810 Å. SAO led the design and construction of the telescope feed, with assistance from Lockheed and Montana State University. The telescope posed a number of implementation challenges, which are discussed here, including the fact that no effective filters exist to isolate the science spectra to the exclusion of the rest of the solar flux, making it necessary to allow full sunlight into the telescope.

This paper presents the overall thermal design of the Interface Region Imaging Spectrograph (IRIS) telescope with focused descriptions of the primary mirror thermal design, telescope active thermal control system, ULE® mirror substrate thermal properties, and the thermal math model supporting the thermal design. The challenge of the IRIS primary mirror thermal design was to manage the un-filtered solar flux that directly impinges on the optical substrate, while maintaining the mirror within a narrow range of temperatures throughout the mission life. This thermal problem is compounded by a change in the absorption properties of ULE over time, due to UV light.

We discuss the details of the Interface Region Imaging Spectrograph (IRIS) telescope primary mirror assembly designcompared to its predecessor used in the Solar Dynamics Observatory Atmospheric Imaging Assembly (SDO-AIA) telescopes. Also included are details of the structural modeling and analysis, mirror optical surface modeling, vibration analysis, and a detailed description of the optical performance verification test program and results.The primary mirror assembly of the IRIS telescope was adapted from an existing design used on the SDO-AIA telescopes. The IRIS telescope was optimized for performance at 1369Å and 2810Å with a required 0.4 arc-second-resolution calling for a significant improvement to the mounted mirror optical surface quality over the existing SDOAIA design.To improve the optical performance, the proven bonded flexure heritage design was augmented with a novel “kinematic” mount used to secure the assembly to the telescope tube. The 200mm diameter concave mirror was fabricated from Corning ULE/RE Code 7973 EUV Premium Grade, Ultra Low Expansion Glass material and polished to better than 12ÅRMS surface roughness. The mirror is supported by three bonded titanium flexures fastened to a rigid titanium cell plate.A 25Å RMS figure error was allocated in the error budget for the mounted, coated primary mirror. The first moderesonance for the mirror was specified to be <100 Hz while surviving an expected launch load of 30G’s. The mirrorassembly was designed to operate from +14°C to +26°C with survival limits specified at -20°C to +35°C.

The Multi Element Telescope for Imaging and Spectroscopy (METIS) coronagraph is an instrument belonging to the SOLar Orbiter(SOLO) mission payload which will perform the imaging of the solar corona in three different spectral ranges: 30.4 nm (He-II Lyman-α line), 121.6 nm (H-I Lyman- α line) and visible spectral range (500-650 nm). Optical coatings with high reflectance performances at the interested wavelengths are required to collect enough light at the detector level. Different multilayer structures based on Si/Mo couples with appropriate capping layers have been already designed and tested to achieve this purpose. A model has been developed in order to estimate the efficiency's performances of the instrument on the whole field of view (FoV) by considering the ray paths. The results shown have been obtained taking into account of the experimental results on multilayers structures previously tested and the optical design of the instrument.

METIS (Multi Element Telescope for Imaging and Spectroscopy) METIS, the “Multi Element Telescope for Imaging and Spectroscopy”, is a coronagraph selected by the European Space Agency to be part of the payload of the Solar Orbiter mission to be launched in 2017. The mission profile will bring the Solar Orbiter spacecraft as close to the Sun as 0.3 A.U., and up to 35° out-of-ecliptic providing a unique platform for helio-synchronous observations of the Sun and its polar regions. METIS coronagraph is designed for multi-wavelength imaging and spectroscopy of the solar corona. This presentation gives an overview of the innovative design elements of the METIS coronagraph. These elements include: i) multi-wavelength, reflecting Gregorian-telescope; ii) multilayer coating optimized for the extreme UV (30.4 nm, HeII Lyman-α) with a reflecting cap-layer for the UV (121.6 nm, HI Lyman-α) and visible-light (590-650); iii) inverse external-occulter scheme for reduced thermal load at spacecraft peri-helion; iv) EUV/UV spectrograph using the telescope primary mirror to feed a 1^st and 4^th-order spherical varied line-spaced (SVLS) grating placed on a section of the secondary mirror; v) liquid crystals electro-optic polarimeter for observations of the visible-light K-corona. The expected performances are also presented.

METIS (Multi Element Telescope for Imaging and Spectroscopy) is one of the instruments included in the science payload of the ESA mission Solar Orbiter: a coronograph able to perform broadband polarization imaging in the visible range, and narrow band imaging in UV (HI Lyman-α) and EUV (HeII Lyman-α). In addition, it will acquire spectra of the solar corona simultaneously to UV/EUV imaging. It will be equipped with two detectors: a hybrid APS dedicated to the visible channel and an Intensified APS for the UV/EUV channel. The spectroscopic channel will share the same detector as the UV/EUV corona imaging, with the spectrum imaged on a portion of the detector not used by the corona image. We present the development of the UV/EUV detector consisting of a CMOS APS imaging device to be coupled with a microchannel plate intensifier. Other than constraints related to the harsh environment (radiation, temperature, visible stray-light), the METIS UV detector has the additional challenge of managing different count rates associated with the three different kind of measurements (UV imaging, EUV imaging and spectroscopy). The required dynamic range is further extended since observations will be planned at different distances from the Sun, varying image scale over a fixed vignetting function. We will present the architecture of this UV detector, describing the prototype developed in order to optimize the performance on the overall dynamic range required by METIS.

METIS, the "Multi Element Telescope for Imaging and Spectroscopy", is a coronagraph of the Solar Orbiter mission to be launched in 2017. The METIS coronagraph includes three optical paths for i) broad-band imaging of the full corona in polarized visible-light (590-650 nm); ii) narrow-band coronal imaging in the UV HI Ly α (121.6 nm) and extreme-UV He II Ly α (30.4 nm), and iii) spectroscopic observations of the HI and He II Ly α. This presentation describes the optical design of the METIS visible-light path for imaging polarimetry of the K-corona. The achromatic polarimeter's requirements on polarization sensitivity, achromatic response and instrumental polarization control are described. The expected performances of the visible-light path are also presented.

The Spectrometer Telescope for Imaging X-rays (STIX) is one of 10 instruments on board Solar Orbiter, a confirmed Mclass mission of the European Space Agency (ESA) within the Cosmic Vision program scheduled to be launched in 2017. STIX applies a Fourier-imaging technique using a set of tungsten grids (at pitches from 0.038 to 1 mm) in front of 32 pixelized CdTe detectors to provide imaging spectroscopy of solar thermal and non-thermal hard X-ray emissions from 4 to 150 keV. The status of the instrument reviewed in this paper is based on the design that passed the Preliminary Design Review (PDR) in early 2012. Particular emphasis is given to the first light of the detector system called Caliste-SO.

There is a basic need both in X-ray astronomy and in synchrotron X-ray optics to be able to modify the shape of an optic via an external source of actuation. We describe a technique of shape modification that can be applied to thin walled (~ 100-400 micron thickness) electroformed replicated optics or glass optics to improve the near net shape of the mirror as well as the mid-frequency (~ 2-10 mm length scales) ripple. The process involves sputter deposition of a magnetic smart material (MSM) film onto a magnetically hard material (i.e., one that retains a magnetic field, e.g. the material in hard disk drives). The MSM material exhibits strains about 400 times stronger than ordinary ferromagnetic materials. The deformation process involves a magnetic write head which traverses the surface, and under the guidance of active metrology feedback, locally magnetizes the surface to impart strain where needed. We describe the results of our current progress toward our ultimate goal of improving the angular resolution of grazing incidence optics.

Innovative X-ray ray imaging optic technologies, Silicon Pore Optics for example, are often characterised by large length to pore diameter aspect ratios. Such ratios present challenges to the deposition of reflectivity enhancing metallic coatings onto the mirror substrate surfaces. The technique of Atomic Layer Deposition (ALD) is perfectly suited to addressing this challenge due to the inherent self-limiting nature of the process which yields highly uniform coatings with surface roughness compatible with the requirements of high resolution X-ray imaging. We describe the results of a project aimed at developing an optimised ALD reactor and process to coat the internal wall surfaces of high aspect ratio samples with a uniform and smooth metallic layer. For sample substrates of aspect ratio ~100 the reactor has realised an average gradient of 1nm in the thickness of an Al₂O₃ coating on the internal walls of a 76 mm long glass tube.

Observations in the far ultraviolet (FUV) at wavelengths below ~125 nm, which include the H Lyman series and the spectral lines of many other important species, are expected to unveil fundamental information for solar physics and astrophysics. Among these, observations of the solar corona at 102.6 nm H Lyman β are of high interest, but they may be masked by the strong H Lyman α at 121.6 nm. This goal has been addressed here through the development of novel multilayer coatings with high reflectance at 102.6 nm and at the same time a low reflectance at 121.6 nm; the latter wavelength is mostly absorbed. An efficient reflection/rejection coating is not straightforward because of the lack of high-transmission materials in the short FUV. We have designed and prepared novel multilayers with combinations of the following materials: Al, LiF, SiC and C. Various combinations were found to display a high reflectance ratio at 102.6/121.6 nm when fresh. Some of them resulted in an undesired reflectance increase at 121.6 nm for the samples aged for a few weeks. The most promising multilayers are based on Al/LiF/SiC/LiF (starting with the innermost layer), which resulted in a good performance and a small evolution after months of storage in a desiccator. At the same time, these multilayers may the most efficient reflective narrowband coatings that have been developed with a peak wavelength in the ~100-130 nm.

Current FUV instrumentation is seriously compromised by poor reflectivity. The best existing coatings for the 90 – 115 nm range are SiC (30% reflectivity across the band) and LiF/Aluminum (60% reflectivity from 100 nm to 115 nm). An improved coating therefore would enable the production of vastly more sensitive instruments in the 90 – 200 nm range. An additional goal in the development of an alternate FUV coating is to overcome the well-documented hygroscopic behaviors of LiF coatings, which currently impose handling concerns that in turn drive cost and schedule. The coatings we will develop in this effort must also function well through the conventional silicon-based detector bandpass (200 nm to 1100 nm). By ensuring that these new coatings are usable at many wavelengths, we will make it possible to incorporate ultraviolet instruments into future large missions without compromising the science capability of other instruments or increasing cost and risk due to handling issues. We present new results of the coating process and discuss our new ALD processes.

The corrosion mechanisms in Mg/SiC multilayers have been elucidated and corrosion-resistant Mg/SiC multilayer coatings have been demonstrated using spontaneously intermixed Al-Mg corrosion barrier layers. The corrosion-resistant Mg/SiC multilayers can achieve high reflectance simultaneously in up to three narrow wavelength bands within the 25-80 nm wavelength region, making them attractive candidates for solar physics instrumentation and for other applications.

X-ray reflective coating for next generation’s lightweight, high resolution optics for astronomy requires thin-film deposition that is precisely fine-tuned so that it will not distort the thin sub-mm substrates. Film of very low stress is required. Films with multi-layer or bi-layer can be deposited to give an effective low stress which cause negligible distortion. Alternatively, mirror distortion can be cancelled by precisely balancing the deformation by coating films on both sides of the substrates. We have been developing techniques to coat glass substrates that can provide good reflectivity in the soft x-ray band below 10 keV, and yet introduce negligible surface distortion for arc-second optics. These efforts include: low-stress deposition by magnetron sputtering and atomic layer deposition of the metals, balancing of gross deformation with two-layer depositions of opposite stresses and with depositions on both sides of the thin mirrors.

The design of an imaging spectrograph operating at grazing incidence and stigmatic in a large field-of-view is presented. It is realized coupling a double telescope and a spectrometer. The instrument may be used for XUV space observations of extended sources, and is particularized to the Sun observation from the Earth. The performances of a laboratory prototype are presented. This instrument covers the 4-20 nm (310-62 eV) spectral region, with a spectral resolution of 0.1% at 10 nm and a spatial resolution of 3.5 arcsec over a field-of-view of 0.5 deg, within a total envelope of 1.2 m. The design and the characterization of the instrument in the whole spectral region of operation are presented.

Idea of ultrahigh cosmic rays (UHECR) measurement from satellites was suggested by Linsley in 1981 and since has being developed into projects of cosmic rays telescopes for International Space Station (ISS): JEM-EUSO - to be installed on the Japanese experimental module and KLYPVE - on the Russian ISS segment. A series of space-based detectors for measurements of background phenomena in those telescopes were developed in Russia (Universitetsky-Tatiana, Universitetsky-Tatiana-2 , Chibis satellites). The satellite Lomonosov with UHECR detector TUS on its board will be launched in 2013. TUS contains multi-channel photo receiver and Fresnel-type mirror manufactured with use of special multi-layer carbon plastic technology in RSC “Energia". In this paper one and two component optical systems with 360 cm entrance diameter and 400 cm focal distance for wide angle detector KLYPVE are studied. In one component case using generalized Davies-Cotton systems (Fresnel-type mirror with ellipsoidal gross surface) it is possible to obtain 8-10° field of view (FoV) with focal spot size less than pixel size equal to 15 x 15 mm. In two component system (parabolic mirror and a Fresnel lens, mounted close to photo receiver) it is possible to increase FoV up to 10-12° and significantly simplify the primary mirror construction.

Experimental demonstrations of the Super-High Angular Resolution Principle (SHARP) for coded aperture imaging are presented. SHARP has been theoretically proven to be an extension of the coded aperture imaging system by taking advantage of the significant diffraction-interference effects of pinholes on the mask, which operates beyond the diffraction limit of a single pinhole. We first set up an optical experiment, the so-called SHARP-O, in order to verify the theoretical predictions on SHARP. The images of point sources are successfully reconstructed, with an angular resolution of about 26 arcsec and position accuracy of 2 arcsec, whereas the diffraction limit of a single mask pinhole in the mask is 870 arcsec. We then set up a SHARP-X demonstration experiment at an X-ray beam line facility; encouraging results are obtained, indicating that the SHARP concept is feasible in the soft X-ray band. It is thus possible to achieve sub-arcsec X-ray imaging with a simple coded mask system working beyond the diffraction limit of a single pinhole.

Lightweight and high resolution mirrors are needed for future space-based X-ray telescopes to achieve advances in high-energy astrophysics. The slumped glass mirror technology in development at NASA GSFC aims to build X-ray mirror modules with an area to mass ratio of ~17 cm²/kg at 1 keV and a resolution of 10 arc-sec Half Power Diameter (HPD) or better at an affordable cost. As the technology nears the performance requirements, additional engineering effort is needed to ensure the modules are compatible with space-flight. This paper describes Flight Mirror Assembly (FMA) designs for several X-ray astrophysics missions studied by NASA and defines generic driving requirements and subsequent verification tests necessary to advance technology readiness for mission implementation. The requirement to perform X-ray testing in a horizontal beam, based on the orientation of existing facilities, is particularly burdensome on the mirror technology, necessitating mechanical over-constraint of the mirror segments and stiffening of the modules in order to prevent self-weight deformation errors from dominating the measured performance. This requirement, in turn, drives the mass and complexity of the system while limiting the testable angular resolution. Design options for a vertical X-ray test facility alleviating these issues are explored. An alternate mirror and module design using kinematic constraint of the mirror segments, enabled by a vertical test facility, is proposed. The kinematic mounting concept has significant advantages including potential for higher angular resolution, simplified mirror integration, and relaxed thermal requirements. However, it presents new challenges including low vibration modes and imperfections in kinematic constraint. Implementation concepts overcoming these challenges are described along with preliminary test and analysis results demonstrating the feasibility of kinematically mounting slumped glass mirror segments.

To provide observations to support areas of current research in high energy astrophysics, future X-ray telescope designs must provide angular resolution of 10 arcsec or better while significantly increasing the total collecting area over previous missions such as Chandra. In such a design the implementation of thin and lightweight segments is critical to the overall performance of the complete X-ray optic assembly. The thin and delicate X-ray segments required for a large collecting area are easily distorted and must be aligned to the arcsecond level and retain accurate alignment over many years. The Next Generation X-ray Optics (NGXO) group at NASA Goddard Space Flight Center has designed, assembled, and implemented new hardware and procedures with the short term goal of aligning three pairs of X-ray segments in a technology demonstration module while maintaining 10 arcsec alignment through environmental testing as part of the eventual design and construction of a full sized module capable of housing hundreds of precisely aligned Xray mirror segments. Recent attempts at multiple segment pair alignment and permanent mounting are described along with an overview of the permanent mounting process. This attempt at alignment and permanent X-ray segment mounting illustrates some of the challenges left to overcome before population of a full sized module can begin.

The degradation of image quality of the nested conical Wolter-I X-ray telescope mainly results from mirror-position tolerance, alignment-bar tolerance and surface-figure tolerance. The analytical approach of the three kinds of tolerance was presented in this paper. Based on the predetermined initial structure, we analyzed and compared image qualities with different tolerances. Furthermore, we simulated the distribution of the spot diagrams and calculated the spatial resolution of the entire system. Shift along the optical axis (Z axis) and rotation around it have no effects on the image quality for position tolerances. However, shift along X, Y directions and rotation around X, Y axes change the distribution of spot diagrams and decrease the spatial resolution. For higher resolution, we should control the alignment-bar tolerance by placing a displacement sensor at the end of the alignment bar. The angular resolution increases from 1' to 13'' as the alignment-bar tolerance decreased from ±15um to ±3um. With respect to surface-figure tolerance, we simulated image qualities by inserting Zernike polynomial to the surface.

We report on recent theoretical and experimental results on diffractive-refractive transmission lenses as promising candidates for next-generation X-ray telescopes with an ultra-high angular resolution. This feature is especially analyzed for elementary refractive, diffractive and dispersion-corrected hybrid lenses and a fundamental limit to the angular resolution for optics of the latter type is identified. An inherent flexibility in adjusting the image sharpness is obtained from the segmentation of an aperture into small partitions, whose degree of coherence can be controlled continuously. Successfully realized monolithic phase zone plates from a spin-coated polymer show the way to the practical implementation of large-scale objectives. Based on these concepts, an arrangement for enhanced and variable high-throughput imaging around the Fe-K_α line at 6.4 keV is finally proposed.

To search for warm-hot intergalactic medium (WHIM), a small satellite mission DIOS (Diffuse Intergalactic Oxygen Surveyer ) is planned and a specially designed four-reflection X-ray telescope (FXT) has been developed as the best fit optics to have a wide field of view and a large effective area. Based on the design of optics and mirror fabrication method developed for FXT, we made the quadrant model with ten nested four-stage mirrors. We describe the expected and the measured performance of this system.

The design of a Wolter X-ray telescope takes into account the geometrical dimensioning of the shells and the choice of the coating for each of them. In this work we present a user-friendly web interface aimed to the design of multishell Wolter telescopes and to the calculation of their effective area. The application is available at http://hea-www.cfa.harvard.edu/WTD/. An example is presented.

The ACIS instrument aboard the Chandra Observatory can be easily damaged by low-energy charged particles, principally protons that implant themselves in the X-ray sensitive CCDs, creating charge traps that degrade the energy resolution and detection efficiency. During periods of high background radiation, ACIS must be moved out of the focal plane of the Chandra telescope and, whenever possible, this action should be taken autonomously since the spacecraft only maintains ground contact for limited periods. The EPHIN detector has been monitoring the particle background since Chandra was launched in 1999, but it is no longer sufficiently sensitive, so the question arose whether ACIS could take over this task. Examining the ACIS data archive, a particular measured quantity—the rate of occurrence of CCD pixels found to contain electric charge that exceeded a predetermined threshold—was often correlated with particle background flux. An algorithm was developed to distinguish this behavior from random fluctuations in the above-threshold rate and the algorithm parameters were adjusted to find the maximum number of high radiation flux “triggers” from the data archive with the minimum number of false positives. The algorithm has been encoded as a patch to ACIS flight software and, after extensive ground testing, has been installed within the instrument.

The efficiencies of the gratings in the High Energy Transmission Grating Spectrometer (HETGS) were updated using in-light observations of bright continuum sources. The procedure first involved verifying that fluxes obtained from the +1 and -1 orders match, which checks that the contaminant model and the CCD quantum efficiencies agree. Then the fluxes derived using the high energy gratings (HEGs) were compared to those derived from the medium energy gratings (MEGs). The flux ratio was fit to a low order polynomial, which was allocated to the MEGs above 1 keV or the HEGs below 1 keV. The resultant efficiencies were tested by examining fits to blazar spectra.

We summarize the evolution of the performance of the X-ray Imaging Spectrometer (XIS) aboard the Suzaku X-ray Astronomy Satellite. Changes due to the orbital environment and updated operating conditions are discussed.

The Cosmic Origins Spectrograph (COS) was installed into the Hubble Space Telescope in May 2009, and has been collecting ultraviolet spectra since then. The Far Ultraviolet channel of COS uses an efficient optical design and a two-segment, large-format Cross Delay Line microchannel plate detector to obtain spectra at medium and low resolution in the far ultraviolet. While the overall instrument performance has been excellent, several long-term trends in performance have been noted and are being addressed. These include a slow decrease in overall sensitivity, which is independent of the illumination and may be due to a degradation of the photocathode with time. In addition, the detector microchannel plates are showing severe gain sag in the regions where the most photons have fallen. As a result, we are in the process of moving the spectra to a new, nearly pristine, location on the detector. This will be the first of several additional lifetime positions which will allow us to collect high-quality spectra for many years to come. We will discuss the factors that led to our decision on where to move next and our progress in moving there, including details of the enabling and calibration activities which are being performed at the new location, and the anticipated performance. We will also address strategies that will be implemented in order to prolong the life at this and subsequent positions.

At the core of the AGILE scientific instrument, designed to operate on a satellite, there is the Gamma Ray Imaging Detector (GRID) consisting of a Silicon Tracker (ST), a Cesium Iodide Mini-Calorimeter and an Anti-Coincidence system of plastic scintillator bars. The ST needs an on-ground calibration with a γ-ray beam to validate the simulation used to calculate the energy response function and the effective area versus the energy and the direction of the γ rays. A tagged γ-ray beam line was designed at the Beam Test Facility (BTF) of the INFN Laboratori Nazionali of Frascati (LNF), based on an electron beam generating γ rays through bremsstrahlung in a position-sensitive target. The γ-ray energy is deduced by the difference with the post-bremsstrahlung electron energy^1-.2 The electron energy is measured by a spectrometer consisting of a dipole magnet and an array of position sensitive silicon strip detectors, the Photon Tagging System (PTS). The use of the combined BTF-PTS system as tagged photon beam requires understanding the efficiency of γ-ray tagging, the probability of fake tagging, the energy resolution and the relation of the PTS hit position versus the γ-ray energy. This paper describes this study comparing data taken during the AGILE calibration occurred in 2005 with simulation.

AGILE is a γ/X-ray telescope which has been in orbit since 23 April 2007. The γ-ray detector, AGILE-GRID, has observed Galactic and extragalactic sources, many of which were collected in the first AGILE Catalog. We present the calibration of the AGILE-GRID using in-flight data and updated Monte Carlo simulations, producing response matrices for the effective area, energy dispersion, and point spread dispersion as a function of pointing direction in instrument coordinates and energy. We performed Monte Carlo simulations in GEANT3 at different γ-ray photon energies and incident angles, using Kalman filter-based photon reconstruction and on-board and on-ground filters. Long integrations of in-flight observations of the Vela, Crab and Geminga sources in broad and narrow energy bands were used to validate

One of the biggest challenges in heliophysics is to decipher the magnetic structure of the solar chromosphere. The importance of measuring the chromospheric magnetic field is due to both the key role the chromosphere plays in energizing and structuring the outer solar atmosphere and the inability of extrapolation of photospheric fields to adequately describe this key boundary region. Over the last few years, significant progress has been made in the spectral line formation of UV lines as well as the MHD modeling of the solar atmosphere. It is found that the Hanle effect in the Lyman-alpha line (121.567 nm) is a most promising diagnostic tool for weaker magnetic fields in the chromosphere and transition region. Based on this groundbreaking research, we propose the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) to NASA as a sounding rocket experiment, for making the first measurement of the linear polarization produced by scattering processes and the Hanle effect in the Lyman-alpha line (121.567 nm), and making the first exploration of the magnetic field in the upper chromosphere and transition region of the Sun. The CLASP instrument consists of a Cassegrain telescope, a rotating 1/2-wave plate, a dual-beam spectrograph assembly with a grating working as a beam splitter, and an identical pair of reflective polarization analyzers each equipped with a CCD camera. We propose to launch CLASP in December 2014.

PolariS (Polarimetry Satellite) is a Japanese small satellite mission dedicated to polarimetry of X-ray and γ-ray sources. The primary aim of the mission is to perform wide band X-ray (4-80 keV) polarimetry of sources brighter than 10 mCrab. For this purpose, Polaris employs three hard X-ray telescopes and two types of focal plane imaging polarimeters. PolariS observations will measure the X-ray polarization for tens of sources including extragalactic ones mostly for the first time. The second purpose of the mission is γ-ray polarimetry of transient sources, such as γ-ray bursts. Wide field polarimeters based on similar concept as that used in the IKAROS/GAP but with higher sensitivity, i.e., polarization measurement of 10 bursts per year, will be employed.

The balloon-borne Gamma-Ray Imager/Polarimeter for Solar flares (GRIPS) instrument will provide a near-optimal combination of high-resolution imaging, spectroscopy, and polarimetry of solar-flare gamma-ray/hard X-ray emissions from ~20 keV to >~10 MeV. GRIPS will address questions raised by recent solar flare observations regarding particle acceleration and energy release, such as: What causes the spatial separation between energetic electrons producing hard X-rays and energetic ions producing gamma-ray lines? How anisotropic are the relativistic electrons, and why can they dominate in the corona? How do the compositions of accelerated and ambient material vary with space and time, and why? The spectrometer/polarimeter consists of sixteen 3D position-sensitive germanium detectors (3D-GeDs), where each energy deposition is individually recorded with an energy resolution of a few keV FWHM and a spatial resolution of <0.1 mm3. Imaging is accomplished by a single multi-pitch rotating modulator (MPRM), a 2.5-cm thick tungstenalloy slit/slat grid with pitches that range quasi-continuously from 1 to 13 mm. The MPRM is situated 8 meters from the spectrometer to provide excellent image quality and unparalleled angular resolution at gamma-ray energies (12.5 arcsec FWHM), sufficient to separate 2.2 MeV footpoint sources for almost all flares. Polarimetry is accomplished by analyzing the anisotropy of reconstructed Compton scattering in the 3D-GeDs (i.e., as an active scatterer), with an estimated minimum detectable polarization of a few percent at 150–650 keV in an X-class flare. GRIPS is scheduled for a continental-US engineering test flight in fall 2013, followed by long or ultra-long duration balloon flights in Antarctica.

The Gravity and Extreme Magnetism Small explorer (GEMS) is an X-ray polarization telescope selected as a NASA small explorer satellite mission. The X-ray Polarimeter on GEMS uses a Time Projection Chamber gas proportional counter to measure the polarization of astrophysical X-rays in the 2-10 keV band by sensing the direction of the track of the primary photoelectron excited by the incident X-ray. We have simulated the expected sensitivity of the polarimeter to polarized X-rays. We use the simulation package Penelope to model the physics of the interaction of the initial photoelectron with the detector gas and to determine the distribution of charge deposited in the detector volume. We then model the charge diffusion in the detector, and produce simulated track images. Within the track reconstruction algorithm we apply cuts on the track shape and focus on the initial photoelectron direction in order to maximize the overall sensitivity of the instrument. Using this technique we have predicted instrument modulation factors μ1₀₀ for 100% polarized X-rays ranging from 10% to over 60% across the 2-10 keV X-ray band. We also discuss the simulation program used to develop and model some of the algorithms used for triggering, and energy measurement of events in the polarimeter.

We are developing a Bragg crystal polarimeter which has high modulation factor. The point we aim is to bend the crystal; by using bent crystal, we can reflect X-ray emission with broadened energy width, focus it on a small detector, which increases S/N ratio, and obtain imaging capability. We bent Si (100) crystal sheets by depositing Diamond-Like Carbon (DLC) on the backside of reflection surface. They are bent by the residual stress between the DLC and crystal. We can control the curvature by changing the DLC thickness. The angular reflectivity was measured with the line emission at 8.04 keV (Cu-Kα). We confirmed that the angular width is broadened to 1 degree, which is equivalent to the energy width of 0.5 keV. The integrated reflectivity becomes larger, as the curvature radius of crystal becomes small. The modulation factor of bent Si is 0.74, which is higher than that of the flat Si of 0.51. Having the wide energy band with the high modulation factor, the bent Si crystal can be a new tool for the X-ray polarimeter. We have also made the bent Ge(111) crystal and measured the same performances. The modulation factor of both the flat and the bent Ge were 0.99 , when using the 8.04 keV (Cu-Kα) beam, as we expected. This means that by choosing crystals, we can make efficient observations with aimed energy band. We report the status of our development.

Pyrolytic Graphite Sheets (PGSs) are produced as convenient thermal interfaces because the highly oriented structure allows for an excellent thermal conductivity. Here we report on the fact that this material can also diffract X-rays. We succeeded in diffracting 5.9 keV and continuum photons on a 25 μm thick PGS, verifying that the lattice spacing is 3.35 Å as expected. The low cost, lightness and the possibility to curve such thin sheets allow to think at new applications in X-ray astronomy.

The prospects for accomplishing x-ray polarization measurements of astronomical sources have grown in recent years, after a hiatus of more than 37 years. Unfortunately, accompanying this long hiatus has been some confusion over the statistical uncertainties associated with x-ray polarization measurements of these sources. We have initiated a program to perform the detailed calculations that will offer insights into the uncertainties associated with x-ray polarization measurements. Here we describe a mathematical formalism for determining the 1- and 2-parameter errors in the magnitude and position angle of x-ray (linear) polarization in the presence of a (polarized or unpolarized) background. We further review relevant statistics—including clearly distinguishing between the Minimum Detectable Polarization (MDP) and the accuracy of a polarization measurement.

Today it is widely recognised that a measurement of the polarization status of cosmic sources high energy emission is a key observational parameter to understand the active production mechanism and its geometry. Therefore new instrumentation operating in the hard X/soft γ rays energy range should be optimized also for this type of measurement. In this framework, we present the concept of a small high-performance spectrometer designed for polarimetry between 100 and 1000 keV suitable as a stratospheric balloon-borne payload dedicated to perform an accurate and reliable measurement of the polarization status of the Crab pulsar, i.e. the polarization level and direction. The detector with 3D spatial resolution is based on a CZT spectrometer in a highly segmented configuration designed to operate as a high performance scattering polarimeter. We discuss different configurations based on recent development results and possible improvements currently under study. Furthermore we describe a possible baseline design of the payload, which can be also seen as a pathfinder for a high performance focal plane detector in new hard X and soft gamma ray focussing telescopes and/or advanced Compton instruments. Finally we present preliminary data from Montecarlo undergoing studies to determine the best trade-off between polarimetric performance and detector design complexity.

Importance of polarisation measurement of X-rays from celestial sources has been realized for long time. Such measurements can provide unique opportunity to study the behaviour of matter and radiation under extreme magnetic and gravitational fields. However sensitivity of the X-ray polarimeters has always been an issue and as a result no X-ray polarization measurement has been flown in last three decades. The situation is expected to change in near future with launch of GEMS, but these polarisation measurements will be limited to energies below 10KeV. On the other hand most of the X-ray sources are expected to have higher degree of polarisation at higher energies. With the advent of high energy focussing telescopes (e.g. NuSTAR, ASTRO-H), it is now possible to design a focal plane Compton polarimeter which can be sensitive upto 80KeV. However, X-ray polarisation measurement is extremely photon hungry. Therefore, a dedicated X-ray polarimeter always has lower sensitivity when compared to any other type of X-ray detector for equal collecting area and time. In this context, we explore a new design of hard X-ray focal plane detector which can provide simultaneous measurements of X-ray polarisation measurements along with high resolution X-ray spectroscopy as well as timing. This design employs a sandwich of a 0.5mm thick Si detector and 10mm thick plastic detector which is surrounded by a cylindrical array of scintillator detectors. Here we present results of detailed Geant4 simulations for estimating sensitivity of this configuration.

POLAR is a Gamma-Ray Burst (GRB) polarization experiment in the energy range 50-500 keV. Detection principle of the gamma-ray polarization is based on the anisotropy of the Compton scattering. POLAR consists of 1600 low-Z plastic scintillator bars, read out by 25 flat-panel multianode photomultipliers. Simulations and experiments have shown that the polarization degree and angle can be retrieved from the modulation curves with the required accuracy. POLAR can reach a minimum detectable polarization of about 10%(3-sigma level) for several strongest GRB detections per year. Construction and assembly of the Qualification Model (QM) are ongoing, in view of a flight onboard of the Chinese Spacelab TG-2 scheduled for 2014.

Ultra Violet Imaging Telescope on ASTROSAT Satellite mission is a suite of Far Ultra Violet (FUV; 130 - 180 nm), Near Ultra Violet (NUV; 200 - 300 nm) and Visible band (VIS; 320-550nm) imagers. ASTROSAT is a first multi wavelength mission of INDIA. UVIT will image the selected regions of the sky simultaneously in three channels & observe young stars, galaxies, bright UV Sources. FOV in each of the 3 channels is ~ 28 arc-minute. Targeted angular resolution in the resulting UV images is better than 1.8 arc-second (better than 2.0 arc-second for the visible channel). Two identical co-aligned telescopes (T1, T2) of Ritchey-Chretien configuration (Primary mirror of ~375 mm diameter) collect the celestial radiation and feed to the detector system via a selectable filter on a filter wheel mechanism; gratings are available in the filter wheels of FUV and NUV channels for slit-less low resolution spectroscopy. The detector system for each of the 3 channels is generically identical. One telescope images in the FUV channel, and other images in NUV and VIS channels. One time open-able mechanical cover on each telescope also works as Sun-shield after deployment. We will present the optical tests and calibrations done on the two telescopes. Results on vibrations test and thermo-vacuum tests on the engineering model will also be presented.

Probing of Hermean Exosphere By Ultraviolet Spectroscopy (PHEBUS) is a spectrometer that will fly on board of the BepiColombo mission to investigate the composition and dynamic of Mercury’s exosphere. Calibration of QM and FM instrument are on going. An approach based on the Mueller Matrix formalism is adopted to determine the pure efficiency of the instrument (PHEBUS). The results obtained show that this approach is a complete and versatile method to perform the radiometric calibration of a space instrument.

We investigate the proton fluence and particle background for the Micro-Channel-Plate X-ray Telescope (MXT) instrument aboard the SVOM satellite, to be placed in a Low Earth Orbit (LEO) at ~600 km altitude and ~30° inclination. The adopted detector at the focal plane is a pn-CCD similar to that used on eROSITA. Monte-Carlo simulations aim at identifying and comparing different possible solutions for the design of the MXT focal plane, in order to conveniently reduce possible radiation damages and the particle induced background. We give here a description of the LEO radiation environment, and present some results of particle background simulations referring to the present baseline configuration.

The Nuclear Compton Telescope (NCT) is a balloon-borne soft γ-ray (0.2-10 MeV) telescope designed to perform wide-field imaging, high-resolution spectroscopy, and novel polarization analysis of astrophysical sources. NCT employs a novel Compton telescope design, utilizing 12 high spectral resolution germanium detectors, with the ability to localize photon interaction in three dimensions. NCT underwent its first science flight from Fort Sumner, NM in Spring 2009, and was partially destroyed during a second launch attempt from Alice Spring, Australia in Spring 2010. We have begun the rebuilding process and are using this as an opportunity to update and optimize various aspects of NCT. The cryostat which houses the 12 germanium detectors is being redesigned so as to accommodate the detectors in a new configuration, which will increase the effective area and improve the on-axis performance as well as polarization sensitivity of NCT. We will be replacing the liquid nitrogen detector cooling system with a cryocooler system which will allow for long duration flights. Various structural changes to NCT, such as the use of an all new gondola, will affect the physical layout of the electronics and instrument subsystems. We expect to return to flight readiness by Fall 2013, at which point we will recommence science flights. We will discuss science goals for the rebuilt NCT as well as proposed flight campaigns.

The scientific objective of the X-ray Advanced Concepts Testbed (XACT) is to measure the X-ray polarization properties of the Crab Nebula, the Crab pulsar, and the accreting binary Her X-1. Polarimetry is a powerful tool for astrophysical investigation that has yet to be exploited in the X-ray band, where it promises unique insights into neutron stars, black holes, and other extreme-physics environments. With powerful new enabling technologies, XACT will demonstrate X-ray polarimetry as a practical and flight-ready astronomical technique. Additional technologies that XACT will bring to flight readiness will also provide new X-ray optics and calibration capabilities for NASA missions that pursue space-based X-ray spectroscopy, timing, and photometry.

The capability of NuSTAR to detect polarization in the Compton scattering regime (>50 keV) has been investigated. The NuSTAR mission, flown on June 2012 a Low Earth Orbit (LEO), provides a unique possibility to confirm the findings of INTEGRAL on the polarization of cosmic sources in the hard X-rays. Each of the two focal plane detectors are high resolution pixellated CZT arrays, sensitive in the energy range ~ 3 - 80 keV. These units have intrinsic polarization capabilities when the proper information on the double events is transmitted on ground. In this case it will be possible to detect polarization from bright sources on timescales of the order of 10⁵ s

The Point Spread Function (PSF) of the eROSITA miror modules is specified to have an on-axis Half Energy Width (HEW) of 15 arcsec. This is only slightly larger than the eROSITA pixel size of 75 microns, which corresponds to 9.6 arcsec at the PANTER test facility, where the PSF is being measured with a prototype of the eROSITA CCD. We have developed a fast algorithm which provides a substantially higher spatial resolution by utilizing the information contained in the charge ratios of split events. By applying this algorithm to measurements where the CCD is systematically shifted in subpixel increments (typically in a 12x12 pattern), we are able to achieve an effective resolution of ~2 arcsec for specific pixel patterns. This algorithm can also be used to compute the two dimensional probability distribution for detecting a photon from an incident point-like beam, for each combination of photon energy, low energy threshold, selected pixel patterns, and subpixel scan properties. These maps allow us to deconvolve the measured PSF and thus to minimize the influence of the spatial detector resolution on the determination of the eROSITA mirror HEW. After launch, the algorithm for improving the spatial resolution by reconstructing the subpixel position will also be applied to the science data.

Due to the particle background and radiation damage in orbit, the CCDs aboard X-ray astronomical satellites (such as eROSITA) tend to degrade in their performance, especially in the charge transfer inefficiency (CTI). The on-board Calibration Source based on Fe-55 will be used to monitor the CTI and the gain. It provides Mn-Kα (5.89 keV) and Mn-Kβ (6.49 keV) lines (accompanied by Auger electrons), but also the Al-K (1.49 keV) and Ti-Kα (4.51 keV) and Ti-Kβ (4.93 keV) fluorescence lines from a target made of aluminum and a contribution of titanium. Measurements with the Calibration Source will be used to compare the on-board CTI with the CTI measured on ground and to modify the CTI correction. We summarize the design and trade-off analysis of the internal eROSITA calibration source and present results obtained with TRoPIC (eROSITA prototype camera) at the PANTER X-ray test facility in the energy range 0.5−250 keV. Various geometries have been tested to optimize the homogeneity of the calibration lines in the focal plane, the overall efficiency, and the line ratios between Mn-K and Al-K. Additionally, multi-component target materials (titanium and silver in addition to aluminum) have been tested. Moreover, the required source strength has been determined to obtain enough photons from the source after several years when radiation damage becomes significant and the source intensity has decayed (T_1/2 ~ 999 d). Finally, also measurements to determine the electron content have been performed.

The X-ray telescope eROSITA is the main instrument besides the Russian ART-XC on the Spektrum-Rontgen-Gamma mission. Starting from 2014, an all-sky survey will be performed in the range between 0.3-10keV, followed by pointed observations. The main objective of thismission is the detection of 100 0000 galaxy clusters in order to constrain cosmological parameters, amongst others the density distribution and evolution of dark energy. Due to the minimum lifetime of seven years the thermal control system has to be completely passive without any consumables. With the ideal operational temperature of the CCD cameras being between 173K and 183K, this requires a very effective heat rejection system, consisting of a complex heat pipe system and a good thermal insulation. Simultaneously, a very sensitive temperature control via variable conductance heat pipes is implemented. For special outgassing requirements at the betinning of the mission these heat pipes are not working after launch but can be switched on any time. On the other hand the mirror moduules have to be tempered at room temperature and more than 200W of the electronics have to be dissipated without affecting the surrounding components or the satellite structure. The thermal control system has to be able to keep up the required temperature range and has to guarantee the optimum working conditions for all parts of the instrument. Calculations and verification tests validated the thermal concept.

The SXS instrument is the Soft X-ray micro-calorimeter Spectrometer planned for the Japanese ASTRO-H satellite, scheduled to be launched in 2014. In this paper we describe the X-ray calibration sources used in this instrument. These sources use light sensitive photo-cathodes to generate electrons, which in turn generate the X-rays. This design has the unique property to allow for fast discrete pulsations of the generated X-rays. This enables the energy scale calibration of the instrument simultaneously with astronomical observations, without adding to the background in the astronomical data. Flight-model sources have been made, and a number of them have been operating in the past several months to monitor their behaviour. Here we report on the characterisation and performance of these sources. In addition, we will elaborate on the nature and expected accuracy of the energy calibration, in relation to the expected stability of the instrument, given the calibration source strength and its mode of operation.

The Hard X-ray Telescopes on Astro-H have a 12-meter focal length. In order to achieve this long focal length and still fit compactly in the H-IIA launch fairing, the detectors are mounted at the end of an extendable optical bench that will be deployed in orbit. Once in operations, the spacecraft will experience distortions primarily due to thermal fluctuations in low-earth orbit and it is important that thte misalignment between the telescopes and instruments is accurately measured. The Canadian Astro-H Metrology System (CAMS) is a laser alignment system that will measure optical alignment deviations. The CAMS is compact, consumes little power, and is stable over a wide temperature range. The system will be used to measure lateral (X/Y) displacement as well as rotational shifts in the optical bench. In addition, the CAMS data can be used to enhance the quality of the hard X-ray images that will have been degraded by the deviations.

The imaging and spectral performance of CdTe double-sided strip detectors (CdTe-DSDs) was evaluated for the ASTRO-H mission. The charcterized CdTe-DSDs have a strip pitch of 0.25 mm, an imaging area of 3.2 cm × 3.2 cm and a thickness of 0.75 mm. The detector was successfully operated at a temperature of -20°C and with an applied bias voltage of 250 V. By using two-strip events as well as one-strip events for the event reconstruction, a good energy resolution of 2.0 keV at 59.5 keV and a sub-strip spatial resolution was achieved. The hard X-ray and gamma-ray response of CdTe-DSDs is complex due to the properties of CdTe and the small pixel effect. Therefore, one of the issues to investigate is the response of the CdTe-DSD. In order to investigate the spatial dependence of the detector response, we performed fine beam scan experiments at SPring-8, a synchrotron radiation facility. From these experiments, the depth structure of the electric field was determined as well as properties of carriers in the detector and successfully reproduced the experimental data with simulated spectra.

We are developing an ASTRO-H data analysis framework with the Geant4-based Monte Carlo simulation core, and numerical models of the on-orbit environmental radiation and full-satellite mass structure. The framework uses not only Geant4 but also a traditional X-ray mirror ray-tracing simulator, and a file format compatible with the SimX simulator for input and output of celestial body information. The data exchange between the framework and the external software is based on FITS files, which makes it easy to record and trace the internal steps of the whole simulation framework.

The Japanese ASTRO-H mission, planned to be launched in 2014, will carry several instruments for covering a wide energy range from a few keV to 600 keV. Among them there are four thin-foil-nested Wolter-I X-ray telescopes. Two of them are Soft X-ray Telescopes (SXTs) covering up to ~12 keV. Each of them focuses an image on the focal plane detectors of the CCD camera (SXI) and the calorimeter (SXS-XCS), respectively. In 2011, we performed a ground calibration of a quadrant engineering model (EM) of SXT that was fabricated at MASA's Goddard Space Flight Center (GSFC). The ground calibration was made with a combination of the measurements at the GSFC and Institute of Space and Astronautical Science (ISAS) facilities. In this paper we report the results of the calibration at the ISAS 30m beamline facility. We used a raster san method with a pencil beam at the baseline length of 30m. An effective area and angular resolution of the EM quadrant were measured. The effective area is 147 cm² at 1.49 keV and 116 cm² at 4.51 keV, respectively, while the angular longer by ~20mm from nominal length. We also measured imaging performance in separate parts of nested mirrors. The angular resolution of parts at outer radius is larger than those at inner radius, and the quadrant have different focal lengths in radius.

X-ray reflection mirror of the Soft X-ray Telescope onboard ASTRO-H was coated by gold thin layer. Gold have M-shell X-ray absorption edge around 2 keV which is included in the energy band covered with the focal plane detector such as Soft X-ray Imager and Soft X-ray Spectrometer. It is important to make response function taken int account the Au M-dege structure especially for the Soft X-ray Spectrometer because It has unprecedented high energy resolution of 5 eV from 0.3 to 12 keV. We performed the detailed measurements of of reflectivity of the mirror using reflectometer in the synchrotron radiation facility KEK PF BL-11B from Nov. 29, 2011 to Dec. 5. X-ray beam of BL–11B was monochromatized to E/deltaE of 5000 by Double crystal monochromator using Si(111). We obtained the reflectivity at the grazing incident angles of 1.0, 1.2, and 1.4 degrees. While the energy pitch was set to be 2 eV in the 2.1–4.1 keV band, the reflectivity in the 2.2–2.35 keV band was also measured in detail with the energy pitch of 0.25 eV. We report the results and optical parameters of the SXT mirror such as reflectivity, and roughness calculated from the measurements.

The ASTRO-H Hard X-ray Telescope (HXT) to cover hard X-rays up to 80 keV is thin-foil, multi-nested conical optics with depth-graded Pt/C multilayer. The reflectors are made of heat-formed aluminum substrate of the thickness gauged of 200 μm of the alloy 5052, followed by epoxy replication on Pt/C-sputtered smooth Pyrex cylindrical mandrels to acquire the X-ray reflective surface. The epoxy layer is 20 μm depth. In this paper, we report a thermal stress test of the reflectors of the HXT. The reflectors can experience in various temperature environment either in ground or in space. The temperature range can be as wide as several tens degrees in space dependently on the thermal design of the telescope system. We kept the reflectors in the three different temperatures at -5, 50 and 60 degrees, respectively, for a week. It is found that the surface of the reflectors at 60 degrees or higher temperature were significantly changed. The change appears as wrinkles with a typical scale length of a few tens micron meters. It is noticed that the scale length is equivalent to the depth of the epoxy layer, suggesting the existence of the epoxy layer causes the change in the scale length. No changes on the surface were observed from the -5 and 50 degree samples. No change on X-ray reflectivity was also detected from them.

ASTRO-H is a next version of Japanese X=ray astronomy satellite for lunch in 2014. The hard X-rray telescope (HXT) on board the satellite has a cylindrical mirror housing which contains reflection circular mirror foils. In the present paper, vibration properties of the mirror foils installed in the HXT on-board a satellite were investigated. Vibration tests and FEM analysis of mirror foils installed in the part model of HXT were conducted. From the experimental results, it appeared that the mirror had resonant frequenxcies at 64, 73 and 118Hz. The modal shapes of 64 and 73Hz peaks shhoed that the maximum amplitude appeared at edges of the foil. On the other hand, vibration amplitude became maximum at the center in the modal shape of 118 Hz peak. In addition, it appeared that the first peak of the edge mode decreased with increasing acceleration while the second peak had weak dependency on acceleration. These vibration behaviours are thought to be governed degree of constraint of the connections between the foil and alignment bars.

We report recent progresses on the fabrication of pre-collimators (PCs). The PCs are designed to mitigate stray lights for X-ray telescopes to be onboard ASTRO-H. Each PC consists of cylindrical aluminum shells (blades) wiht varying radii of 60-225 mm, alignment frames to guilde the blade positions, and the bade housing body. The alignment frame and the housing are made of Aluminum 6061 and 7075 alloy, respectively. Heat-forming process is introduced to the production to stabilize the blade shape in orbit. Precise curvature of radius (tolerance of 1mm) and the linearity along with the direction of incident X-rays (P.V. < 20 microns) ensure that the blades do not obscure the telescope aperature. Each PC blade is placed precisely on top of the respective reflector mirror shell to reduce off-axis X-ray photons that leads to a "ghost" image within the detector field of view. In September 2010, the PC design--its height, thickness, and material of blades--was fixed and we produced the engineering model (EM) for the Soft X-ray Telescopes (SXTs). Since then, vibration tests for the EM PC unit are carried out twice, verifying that the PC has sufficient structural strength to withstand severe conditions during its launch. The EM PC is also installed onto the SXT mirror housing fabricated at the NASA's GSFC to validate our PC assembly method without any loss of thetelescope's effective aperture area. Since August 2011, we have been manusfacturing the PC blades for the flight models. We hereby show the manufacturing processes and also results of stray-light measurement without PCs for the SXT EM (obtained at ISAS 30m beamline facility) and the HXT FM (obtained at SPring-8 synchrotron radiation facility).

We present recent results of hard X-ray characterization of ASTRO-H HXT at SPring-8. The HXT onboard ASTRO-H is thin-foil, multi-nested conical optics similar to the Suzaku X-ray telescope. To reflect hard X-rays efficiently, reflector surface is coated with depth-graded Pt/C multilayer. The integraion of the HXT-1 mirror module has been completed. This mirror module has been characterized at a synchrotron radiation facility, SPring-8 beamline BL20B2. We have adopted, newly, an active tuning procedure with piezoelectric actuator to improve a focused image confocality. We have measured point spread function and effective area at 30, 40, 50, and 60 keV. An angular resolution of 1.9 arcmin (HPD) at 30 keV was obtained in the full telescope. The effective area of HXT-1 at 30 keV meets the requirements of HXT.

We present the development status of the Pulse Shape Processor (PSP), which is the on-board digital electronics responsible for the signal processing of the X-ray microcalorimeter spectrometer instrument (the Soft X-ray Spectrometer; SXS) for the ASTRO-H satellite planned to be launched in 2014. We finished the design and fabrication for the engineering model, and are currently undertaking a series of performance verification and environmental tests. In this report, we summarize the results obtained in a part of the tests completed in the first half of this year.

We present description and results of the test campaign performed on Silicon Pore Optics (SPO) samples to be used on the ATHENA mission. We perform a pre-coating characterization of the substrates using Atomic Force Microscopy (AFM), X-ray Re ectometry (XRR) and scatter measurements. X-ray tests at DTU Space and correlation between measured roughness and pre-coating characterization are reported. For coating development, a layer of Cr was applied underneath the Ir/B4C bi-layer with the goal of reducing stress, and the use of N2 during the coating process was tested in order to reduce the surface roughness in the coatings. Both processes show promising results. Measurements of the coatings were carried out at the 8 keV X-ray facility at DTU Space and with synchrotron radiation in the laboratory of PTB at BESSY II to determine re ectivity at the grazing incidence angles and energies of ATHENA. Coating development also included a W/Si multilayer coating. We present preliminary results on X-ray Re ectometry and Cross-sectional Transmission Electron Microscopy (TEM) of the W/Si multilayer.

Future large X-ray observatories will be equipped with very large optics obtained by assembling modular optical elements. The final quality of the modular optic is determined by the accuracy in the assembly alignment, but also by the compliance of the focusing elements to the nominal shape and the roughness tolerance in order to avoid excessive levels of X-ray scattering. Because of the large number of modules, quality tests need to be routinely performed to assess the technology readiness, and, in a later phase, to select the most performing stacked blocks to be integrated into the final optic. Besides the usual metrology based on profile and roughness measurements, a direct, at-wavelength, focusing measurement in X-rays would be the most reliable test. Synchrotron light beams are in general not sufficiently broad to cover the aperture of a block without scanning it, which requires a focal spot reconstruction. To this end, we designed a 12 m long X-ray facility to be realized at INAF/ OAB, devoted to the functional tests of the focusing elements. A grazing incidence parabolic mirror and an asymmetric Silicon crystal will produce a wide, parallel, and uniform beam of X-rays to illuminate the entire aperture of the focusing elements. A X-ray camera at the focal distance from the mirrors directly records the image. The tests will be performed at 4.5 keV, with the components operating in gaseous Helium to minimize the absorption.

ATHENA has been the re-scoped IXO mission, and one of the foreseen focal plane instrument was the X-ray Microcalorimeter Spectrometer (XMS) working in the energy range 0.3-10 keV, which was a kilo-pixel array based on TES (Transition Edge Sensor) detectors. The need of an anticoincidence (AC) detector is legitimated by the results performed with GEANT4 simulations about the impact of the non x-ray background onto XMS at L2 orbit (REQ. < 0.02 cts/cm2/s/keV). Our consortium has both developed and tested seveal samples, with increasing area, in order to match the large area of the XMS (64 mm2). Here we show the preliminary results from the last prototype. The results achieved in this work offer a solution to reduce the particle background not only for the presently study mission, but also for any satellite/balloon borne instrument that foresees a TES-based microcalorimeters/bolometers focal plane (from millimeter to x-ray domain).

We present several solutions to reduce the background that will be experienced by the X-ray Microcalorimeter Spectrometer (XMS) aboard of the ATHENA mission due to Galactic Cosmic Rays (GCR) and solar particles present in the second Lagrangian point L2. The configuration presented in this paper is the one adopted for the International X-ray Observatory (IXO) but the derived estimates can be considered a conservative limit for ATHENA, that is the IXO redefined mission proposed to ESA. We used the Geant4 toolkit, a Monte Carlo based simulator, to investigate the rejection efficiency of the anticoincidence system and assess the residual background on the detector. Even though the mission did not pass the down selection of ESA, this work lay the basis of a study for a microcalorimeters-based mission in L2.

The ATHENA X-ray observatory was a European Space Agency project for a L-class mission. ATHENA was to be based upon a simplified IXO design with the number of instruments and the focal length of the Wolter optics being reduced. One of the two instruments, the Wide Field Imager (WFI) was to be a DePFET based focal plane pixel detector, allowing for high time and spatial resolution spectroscopy in the energy-range between 0.1 and 15 keV. In order to fulfill the mission goals a high sensitivity is essential, especially to study faint and extended sources. Thus a detailed understanding of the detector background induced by cosmic ray particles is crucial. During the mission design generally extensive Monte-Carlo simulations are used to estimate the detector background in order to optimize shielding components and software rejection algorithms. The Geant4 toolkit^1,2 is frequently the tool of choice for this purpose. Alongside validation of the simulation environment with XMM-Newton EPIC-pn and Space Shuttle STS-53 data we present estimates for the ATHENA WFI cosmic ray induced background including long-term activation, which demonstrate that DEPFET-technology based detectors are able to achieve the required sensitivity.

We have assembled a stacked setup consisting of a soft and hard X-ray detector with cooling capability and control-, readout-, and data processing electronics at the Institut für Astronomie und Astrophysik Tübingen (IAAT). The detector system is a 64 ×64 DePFET-Matrix in front of a CdTe-Caliste module. The detectors were developed at the Max-Planck Institute Semiconductor Laboratory (HLL) in Neuperlach and the Commissariat a l'Energie Atomique (CEA) in Saclay, respectively. In this combined structure the DePFET detector works as Low Energy Detector (LED) while the Caliste module (HED) only detects the high energy photons that have passed through the LED. In this work we present the current status of the setup. Furthermore, an intended application of the detector system as a polarimeter is described.

The optimization of coating design for the ATHENA mission si described and the possibility of increasing the telescope effective area in the range between 0.1 and 10 keV is investigated. An independent computation of the on-axis effective area based on the mirror design of ATHENA is performed in order to review the current coating baseline. The performance of several material combinations, considering a simple bi-layer, simple multilayer and linear graded multilayer coatings are tested and simulation of the mirror performance considering both the optimized coating design and the coating baseline including on- and off-axis effective area curves are presented. We find that the use of linear graded multilayers can increas by 37% the integraed effective area of ATHENA in the energy range between 0.1 keV and 15keV.

The Large Observatory for X-ray Timing (LOFT) is one of the four candidate ESA M3 missions considered for launch in the timeframe of 2022. It is specifically designed to perform fast X-ray timing and probe the status of the matter near black holes and neutron stars. The LOFT scientific payload consists of a Large Area Detector and a Wide Field Monitor. The LAD is a 10m²-class pointed instrument with high spectral (200 eV @ 6 keV) and timing (< 10 μs) resolution over the 2-80 keV range. It is designed to observe persistent and transient X-ray sources with a very large dynamic range from a few mCrab up to an intensity of 15 Crab. An unprecedented large throughput (~280.000 cts/s from the Crab) is achieved with a segmented detector, making pile-up and dead-time, often worrying or limiting focused experiments, secondary issues. We present the on-board data handling concept that follows the highly segmented and hierarchical structure of the instrument from the front-end electronics to the on-board software. The system features customizable observation modes ranging from event-by-event data for sources below 0.5 Crab to individually adjustable time resolved spectra for the brighter sources. On-board lossless data compression will be applied before transmitting the data to ground.

The Scientific objectives of the LOFT mission, e.g., the study of the Neutron Star equation of state and of the Strong Gravity, require accurate energy, time and flux calibration for the 516k channels of the SDD detectors, as well as the knowledge of the detector dead time and of the detector response with respect to the incident angle of the photons. We report here the evaluations made to assess the calibration issues for the LAD instrument. The strategies for both ground and on-board calibrations, including astrophysical observations, show that the goals are achievable within the current technologies.

The Large Observatory For X-ray Timing (LOFT) is an innovative medium-class mission selected for an assessment phase in the framework of the ESA M3 Cosmic Vision call. LOFT is intended to answer fundamental questions about the behavior of matter in theh very strong gravitational and magnetic fields around compact objects. With an effective area of ~10 m² LOFT will be able to measure very fast variability in the X-ray fluxes and spectra. A good knowledge of the in-orbit background environment is essential to assess the scientific performance of the mission and to optimize the instrument design. The two main contributions to the background are cosmic diffuse X-rays and high energy cosmic rays; also, albedo emission from the Earth is significant. These contributions to the background for both the Large Area Detector and the Wide Field Monitor are discussed, on the basis of extrensive Geant-4 simulations of a simplified instrumental mass model.

The Large Observatory For X-ray Timing (LOFT), selectyed by ESA as one of the four Cosmic Visiion M3 candidate missions to undergo an assessment phase, will revolutionize the study of compact objects in our galaxy and of the brightest supermassive black holes in active galactic nuclei. The Large Area Detector (LAD), carrying an unprecedented effective area of 10 m2, is complemented by a coded-mask Wide Field Monitor, in charge of monitoring a large fraction of the sky potentially accesesible to the LAD, to provide the history and context for the sources observed by LAD and to trigger its observations on their most interesting and extreme states. In this paper we present detailed simulations of the imaging capabilities of the Silicon Drift Detectors developed for the LOFT Wide Field Monitor detection plane. The simulations explore a large parameter space for both the detector design and the environmental conditions, allowing us to optimize the detector characteristcs and demonstrating the X-ray imaging performance of the large-area SDDs in the 2-50 keV energy band.

We present the simulator we developed for the Wide Field Monitor (WFM) aboard the Large Observatory For Xray Timing (LOFT) mission, one of the four ESA M3 candidate missions considered for launch in the 2022–2024 timeframe. The WFM is designed to cover a large FoV in the same bandpass as the Large Area Detector (LAD, almost 50% of its accessible sky in the energy range 2–50 keV), in order to trigger follow-up observations with the LAD for the most interesting sources. Moreover, its design would allow to detect transient events with fluxes down to a few mCrab in 1-day exposure, for which good spectral and timing resolution would be also available (about 300 eV FWHM and 10 μs, respectively). In order to investigate possible WFM configurations satisfying these scientific requirements and assess the instrument performance, an end-to-end WFM simulator has been developed. We can reproduce a typical astrophysical observation, taking into account both mask and detector physical properties. We will discuss the WFM simulator architecture and the derived instrumental response.