This PDF file contains the front matter associated with SPIE Proceedings Volume 9144, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing.

Dedicated to spectroscopic and imaging observations of the ultraviolet sky, the World Space Observatory - Ultraviolet mission is a Russian-Spanish collaboration. The project consists of a 1.7m telescope with instrumentation able to perform: a) high resolution (R ≥50 000) spectroscopy by means of two echellé spectrographs covering the 115–310 nm spectral range; b) long slit (1x75 arcsec) low resolution (R ∼ 1000) spectroscopy with a near-UV channel and a far-UV channel to cover the 115–305 nm spectral range; c) near-UV and a far-UV imaging channels covering the 115-320 nm wavelength range; d) slitless spectroscopy with spectral resolution of about 500 in the full 115–320 nm spectral range. Here we present the WSO-UV focal plane instruments, their status of implementation, and the expected performances.

CASTOR (the Cosmological Advanced Survey Telescope for Optical and uv Research) is a proposed CSA-led mission that would carry out deep, high-resolution imaging at ultraviolet and blue-optical wavelengths. Operating close to the diffraction limit, the 1m CASTOR telescope would have a spatial resolution comparable to the Hubble Space Telescope (HST), but with an instantaneous field of view of 1.2° x 0.6° -- about two hundred times larger than that of the Advanced Camera for Surveys on HST. Imaging would be carried out simultaneously in three non-overlapping bandpasses: UV (0.15-0.3 μm), u′ (0.3-0.4 μm) and g (0.4-0.55 μm). In the blue-optical region, CASTOR imaging would far exceed that from LSST in terms of depth and angular resolution, even after a decade of LSST operations. In this review, we summarize the various technical efforts being carried out in support of the CASTOR mission concept, and describe the potential scientific synergy between the CASTOR, Euclid and WFIRST missions.

Heritage wide-field ultraviolet imagers have observed large (~30°) fields-of-view, but suffer from relatively poor (~0.6°) spatial resolution. Improvements in mirror design and fabrication technology allow for a new two-mirror design that preserves a large (40°x20°) field-of-view, while improving spatial resolution by nearly a factor of ten to 0.07° while imaging onto a flat focal surface. Such an imager has uses in a number of ultraviolet astronomical applications, including plasmaspheric imaging and monitoring of the interplanetary medium.

The Sub-Lyman α Explorer (SubLymE) will be proposed to NASA as a Small Explorer mission in response to the anticipated Announcement of Opportunity in fall 2014. It will provide multi-color imaging in the 102 – 120 nm spectral window with 2 arc second resolution and a field of view 12 arc minutes in diameter. No astronomical imaging has been done in this bandpass previously. SubLymE will enable a host of previously impossible astronomical observations but its optical design and operational planning have been optimized around two key projects. 1: The mission will perform a survey of local galaxies, identifying and characterizing the youngest and most massive stellar clusters in local star-forming and star-bursting galaxies. These stellar clusters drive the physical and chemical evolution of galaxies like the Milky Way. 2: SubLymE will directly measure the amount and spatial distribution of ionizing photon escape from star-forming galaxies in the local universe (0.22 < z < 0.5), a critical measurement for understanding how the intergalactic medium was ionized during the epoch of reionization. We present the current optical design and predicted performance for SubLymE, and summarize its primary science objectives.

The Colorado High-resolution Echelle Stellar Spectrograph (CHESS) is a far ultraviolet (FUV) rocket-borne experiment designed to study the atomic-to-molecular transitions within translucent interstellar clouds. CHESS is an objective echelle spectrograph operating at f/12.4 and resolving power of 120,000 over a band pass of 100 – 160 nm. The echelle flight grating is the product of a research and development project with LightSmyth Inc. and was coated at Goddard Space Flight Center (GSFC) with Al+LiF. It has an empirically-determined groove density of 71.67 grooves/mm. At the Center for Astrophysics and Space Astronomy (CASA) at the University of Colorado (CU), we measured the efficiencies of the peak and adjacent dispersion orders throughout the 90 – 165 nm band pass to characterize the behavior of the grating for pre-flight calibrations and to assess the scattered-light behavior. The crossdispersing grating, developed and ruled by Horiba Jobin-Yvon, is a holographically-ruled, low line density (351 grooves/mm), powered optic with a toroidal surface curvature. The CHESS cross-disperser was also coated at GSFC; Cr+Al+LiF was deposited to enhance far-UV efficiency. Results from final efficiency and reflectivity measurements of both optics are presented. We utilize a cross-strip anode microchannel plate (MCP) detector built by Sensor Sciences to achieve high resolution (25 μm spatial resolution) and data collection rates (~ 10⁶ photons/second) over a large format (40mm round, digitized to 8k x 8k) for the first time in an astronomical sounding rocket flight. The CHESS instrument was successfully launched from White Sands Missile Range on 24 May 2014. We present pre-flight sensitivity, effective area calculations, lab spectra and calibration results, and touch on first results and post-flight calibration plans.

UVIT consists of two co-aligned 38cm telescopes that provide ~1 arsec resolution imaging over 28 arcmin fields, in FUV, NUV, and Visible bands simultaneously. Each channel has a choice of filters, and, for the UV channels, gratings. UVIT is also co-aligned with three X-ray telescopes on the observatory, and all operate together. This paper gives details of the operation and performance of the instrument.

The Extreme Ultraviolet Imager (EUI) on-board the Solar Orbiter mission will provide full-sun and high-resolution image sequences of the solar atmosphere at selected spectral emission lines in the extreme and vacuum ultraviolet. After the breadboarding and prototyping activities that focused on key technologies, the EUI project has completed the design phase and has started the final manufacturing of the instrument and its validation. The EUI instrument has successfully passed its Critical Design Review (CDR). The process validated the detailed design of the Optical Bench unit and of its sub-units (entrance baffles, doors, mirrors, camera, and filter wheel mechanisms), and of the Electronic Box unit. In the same timeframe, the Structural and Thermal Model (STM) test campaign of the two units have been achieved, and allowed to correlate the associated mathematical models. The lessons learned from STM and the detailed design served as input to release the manufacturing of the Qualification Model (QM) and of the Flight Model (FM). The QM will serve to qualify the instrument units and sub-units, in advance of the FM acceptance tests and final on-ground calibration.

METIS is an innovative inverted occulted solar coronagraph capable of obtaining for the first time simultaneous imaging of the full corona in linearly polarized visible-light (580-640 nm) and narrow-band (± 10 nm) ultraviolet H I Ly-α (121.6 nm). It has been selected to fly aboard the Solar Orbiter¹ spacecraft, whose launch is foreseen in July 2017. Thanks to its own capabilities and exploiting the peculiar opportunities offered by the Solar Orbiter planned orbit, METIS will address some of the still open issues in understanding the physical processes in the corona and inner heliosphere. The Solar Orbiter Nominal Mission Phase (NMP) will be characterized by three scientific observing windows per orbit and METIS will perform at least one in-flight calibration per observing window. The two imaging channels of METIS will be calibrated on ground and periodically checked, verified and re-calibrated in-flight. In particular, radiometric calibration images will be needed to determine the absolute brightness of the solar corona. For UV radiometric calibration a set of targets is represented by continuum-emitting early type bright stars (e.g. A and B spectral types) whose photospheres produce a bright far-ultraviolet continuum spectrum stable over long timescales. These stars represent an important reference standard not only for METIS in-flight calibrations but also for other Solar Orbiter instruments and they will be crucial for instruments cross-calibrations as well. For VL radiometric calibration, a set of linearly polarized stars will be used. These targets shall have a minimum degree of linear polarization (DoLP > 5%) and a detectable magnitude, compatible with the instrument integration times constrained by the desired S/N ratio and the characteristics of the spacecraft orbit dynamics.

There is a large gap in between the Integral and Fermi spectral domains that is unobserved since the end of the CGRO mission and its Comptel experiment. There were many attempts to fill this gap but no proposal succeeded yet to convince a space agency to plan a mission. There are many reasons contributing to this situation but the most important one is that neither mirrors nor present particle tracking devices are effective at these energies. We propose here a novel design allowing particle tracking for a gamma-ray telescope in the 5–100 MeV band. The idea of this experiment is to image the ionizing tracks of charged particles using the light produced in a scintillator. The experiment operates as a pair creation telescope at high energy and as a Compton telescope with electron tracking at low energy. The telescope features a large scintillator transparent to the produced scintillation light, an ad-hoc optical system and a high resolution and highly sensitive imager. We review the requirements for each of these sub-systems and propose an experiment design taking into account the space constraints. We emphasize the numerous conceptual advantages of such a system as well as the identified difficulties.

Five years into the Fermi Gamma-ray Space Telescope (Fermi) mission we have learned a great deal about the γ-ray sky, yet many open questions remain, and many new puzzles have arisen. In this contribution we will consider the science drivers for a variety of topics in high-energy gamma-ray astronomy, and how these drivers map into design considerations for future gamma-ray instruments in the energy range above 5 MeV. Specifically, we take the performance parameters and data set of the Large Area Telescope on the Fermi observatory (Fermi-LAT) as a baseline, and consider the scientific questions that could be probed by improving those parameters. We will also discuss the current state of detector technologies used in space-based γ-ray telescopes and discuss the magnitude of advances that would be required to make a future Fermi-like mission transformational enough to warrant the cost and effort. These summaries are intended to be useful for selecting technologies and making basic design decisions for future γ-ray telescopes.

We describe the instrument concept of a high angular resolution telescope dedicated to the sub-GeV (from ≥10 MeV to ≥1 GeV) gamma-ray photon detection. This mission, named PANGU (PAir-productioN Gamma-ray Unit), has been suggested as a candidate for the joint small mission between the European Space Agency (ESA) and the Chinese Academy of Science (CAS). A wide range of topics of both astronomy and fundamental physics can be attacked with PANGU, covering Galactic and extragalactic cosmic-ray physics, extreme physics of a variety of extended (e.g. supernova remnants, galaxies, galaxy clusters) and compact (e.g. black holes, pulsars, gamma-ray bursts) objects, solar and terrestrial gamma-ray phenomena, and searching for dark matter decay and/or annihilation signature etc. The unprecedented point spread function can be achieved with a pair-production telescope with a large number of thin active tracking layers to precisely reconstruct the pair-produced electron and positron tracks. Scintillating fibers or thin silicon micro-strip detectors are suitable technology for such a tracker. The energy measurement is achieved by measuring the momentum of the electrons and positrons through a magnetic field. The innovated spectrometer approach provides superior photon pointing resolution, and is particular suitable in the sub-GeV range. The level of tracking precision makes it possible to measure the polarization of gamma rays, which would open up a new frontier in gamma-ray astronomy. The frequent full-sky survey at sub-GeV with PANGU's large field of view and significantly improved point spread function would provide crucial information to GeV-TeV astrophysics for current/future missions including Fermi, DAMPE, HERD, and CTA, and other multi-wavelength telescopes.

As a next generation MeV gamma-ray telescope, we develop an electron-tracking Compton camera (ETCC) that consists of a gaseous electron tracker surrounded by pixel scintillator arrays. The tracks of the Compton-recoil electron measured by the tracker restrict the incident gamma-ray direction to an arc region on the sky and reject background by using the energy loss rate dE/dx and a Compton-kinematics test. In 2013, we constructed, for a balloon experiment, a 30-cm-cubic ETCC with an effective area of ~1 cm² for detecting sub-MeV gamma rays (5 σ detection of the Crab Nebula for 4 h). In future work, we will extend this ETCC to an effective area of ~10 cm². In the present paper, we report the performance of the current ETCC.

The All-Sky Compton Imager (ASCI) is a mission concept for MeV Gamma-Ray astronomy. It consists of a compact array of cross-strip germanium detectors, shielded only by a plastic anticoicidence, and weighting less than 100 kg. Situated on a deployable structure at a distance of 10 m from the spacecraft orbiting at L2 or in a HEO, the ASCI not only avoids albedo- and spacecraft-induced background, but it benefits from a continuous all-sky exposure. The modest effective area is more than compensated by the 4 π field-of-view. Despite its small size, ASCI's γ-ray line sensitivity after its nominal lifetime of 3 years is ~ 10^-6 ph cm^-2 s^-1 at 1 MeV for every γ-ray source in the sky. With its high spectral and 3-D spatial resolution, the ASCI will perform sensitive γray spectroscopy and polarimetry in the energy band 100 keV-10 MeV. The All-Sky Compton Imager is particularly well suited to the task of measuring the Cosmic Gamma-Ray Background – and simultaneously covering the wide range of science topics in gamma-ray astronomy.

PACT is a Pair And Compton Telescope that aims to make a sensitive survey of the gamma-ray sky between 100 keV and 100 MeV. It will be devoted to the detection of radioactivity lines from present and past supernova explosions, the observation of thousands of new blazars, and the study of polarized radiations from gamma-ray bursts, pulsars and accreting black holes. It will reach a sensitivity of one to two orders of magnitude lower than COMPTEL/CGRO (e.g. about 50 times lower for the broad-band, survey sensitivity at 1 MeV after 5 years). The concept of PACT will be proposed for the AstroMeV mission in the framework of the M4 ESA Call. It is based upon three main components: a silicon-based gamma-ray tracker, a crystal-based calorimeter (e.g. CeBr3:Sr), and an anticoincidence detector made of plastic scintillator panels. Prototypes of these detector planes are currently tested in the laboratories.

Recent progress in wide field of view or all-sky observations such as Swift/BAT hard X-ray monitor and Fermi GeV gamma-ray observatory has opened up a new era of time-domain high energy astro-physics addressing new insight in, e.g., particle acceleration in the universe. MeV coverage with comparable sensitivity, i.e. 1 ~ 10 mCrab is missing and a new MeV all-sky observatory is needed. These new MeV mission tend to be large, power- consuming and hence expensive, and its realization is yet to come. A compact sub-MeV (0.2-2 MeV) all-sky mission is proposed as a path finder for such mission. It is based on a Si/CdTe semiconductor Compton telescope technology employed in the soft gamma-ray detector onboard ASTRO-H, to be launched in to orbit on late 2015. The mission is kept as small as 0:5 X 0:5 X 0:4 m³, 150 kg in weight and 200 W in power in place of the band coverage above a few MeV, in favor of early realization as a sub-payload to other large platforms, such as the international space station.

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 hard X-ray (10-80 keV) polarimetry of sources brighter than 10 mCrab. For this purpose, PolariS employs three hard X-ray telescopes and scattering type imaging polarimeters. PolariS 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 (GRBs). Wide field polarimeters based on similar concept as that used in the IKAROS/GAP but with higher sensitivity will be used, and polarization measurement of 10 GRBs per year is expected.

To measure the polarization of gamma-ray bursts in X-ray energy band, we have developed a 50 kg micro-satellite named "SUBAME". The satellite has a compact and high-sensitive hard X-ray polarimeter employing newly-developed shock resistant multi-anode photomultipliers and Si avalanche photodiodes. Thanks to the ultra low-noise detectors and signal processors, the polarimeter can cover a wide energy range of 30􀀀200 keV even at 25°C with a high modulation factor of 62 %. TSUBAME is in the phase of final functional tests waiting for shipping to Baikonur and will be launched into a sun-synchronous orbit at an altitude of 700 km in late 2014. In this paper, the pre-ight performance of the gamma-ray detector system and the satellite bus system are presented.

POLAR is a joint European-Chinese experiment aimed at a precise measurement of hard X-ray polarization (50-500 keV) of the prompt emission of Gamma-Ray Bursts. The main aim is a better understanding of the geometry of astrophysical sources and of the X-ray emission mechanisms. POLAR is a compact Compton polarimeter characterized by a large modulation factor, effective area, and field of view. It consists of 1600 low-Z plastic scintillator bars read out by 25 at-panel multi-anode photomultipliers. The incoming X-rays undergo Compton scattering in the bars and produce a modulation pattern; experiments with polarized synchrotron radiation and GEANT4 Monte Carlo simulations have shown that the polarization degree and angle can be retrieved from this pattern with the accuracy necessary for identifying the GRB mechanism. The flight model of POLAR is currently under construction in Geneva. The POLAR instrument will be placed onboard the Chinese spacelab TG-2, scheduled for launch in low Earth orbit in 2015. The main milestones of the space qualification campaign will be described in the paper.

X-ray polarization measurements hold great promise for studying the geometry and emission mechanisms in the strong gravitational and magnetic fields that surround black holes and neutron stars. In spite of this, the observational situation remains very limited; the last instrument dedicated to X-ray polarimetry flew decades ago on OSO-8, and the few recent measurements have been made by instruments optimized for other purposes. However, the technical capabilities to greatly advance the observational situation are in hand. Recent developments in micro-pattern gas detectors allow use of the polarization sensitivity of the photo-electric effect, which is the dominant interaction in the band above 2 keV. We present the scientific and technical requirements for an X-ray polarization observatory consistent with the scope of a NASA Small Explorer (SMEX) mission, along with a representative catalog of what the observational capabilities and expected sensitivities for the first year of operation could be. The mission is based on the technically robust design of the Gravity and Extreme Magnetism SMEX (GEMS) which completed a Phase B study and Preliminary Design Review in 2012. The GEMS mission is enabled by time projection detectors sensitive to the photo-electric effect. Prototype detectors have been designed, and provide engineering and performance data which support the mission design. The detectors are further characterized by low background, modest spectral resolution, and sub-millisecond timing resolution. The mission also incorporates high efficiency grazing incidence X-ray mirrors, design features that reduce systematic errors (identical telescopes at different azimuthal angles with respect to the look axis, and mounted on a rotating spacecraft platform), and a moderate capability to perform Target of Opportunity observations. The mission operates autonomously in a low earth, low inclination orbit with one to ten downlinks per day and one or more uplinks per week. Data and calibration products will be made available through the High Energy Astrophysics Science and Archival Research Center (HEASARC).

Polarimeters for Energetic Transients (POET) is a mission concept designed to t within the envelope of a NASA Small Explorer (SMEX) mission. POET will use X-ray and gamma-ray polarimetry to uncover the energy release mechanism associated with the formation of stellar-mass black holes and investigate the physics of extreme magnetic ields in the vicinity of compact objects. Two wide-FoV, non-imaging polarimeters will provide polarization measurements over the broad energy range from about 2 keV up to about 500 keV. A Compton scatter polarimeter, using an array of independent scintillation detector elements, will be used to collect data from 50 keV up to 500 keV. At low energies (2{15 keV), data will be provided by a photoelectric polarimeter based on the use of a Time Projection Chamber for photoelectron tracking. During a two-year baseline mission, POET will be able to collect data that will allow us to distinguish between three basic models for the inner jet of gamma-ray bursts.

NASA's Chandra X-Ray Observatory, designed for three years of operation with a goal of five years, is now entering its 15-th year of operation. Thanks to its superb angular resolution, the Observatory continues to yield new and exciting results, many of which were totally unanticipated prior to launch. We discuss the current technical status, review some recent scientific highlights, indicate a few future directions, and present what we are the most important lessons learned from our experience of building and operating this great observatory.

2014 marks the crystal (15^th) anniversary of the launch of the Chandra X-ray Observatory, which began its existence as the Advanced X-ray Astrophysics Facility (AXAF). This paper offers some of the major lessons learned by some of the key members of the Chandra Telescope team. We offer some of the lessons gleaned from our experiences developing, designing, building and testing the telescope and its subsystems, with 15 years of hindsight. Among the topics to be discussed are the early developmental tests, known as VETA-I and VETA-II, requirements derivation, the impact of late requirements and reflection on the conservatism in the design process.

The RGS instrument is the X–ray spectrometer on board the XMM-Newton satellite, launched December 1999, and still fully operational. It consists of a reflection grating to disperse the incoming X–rays and a CCD camera as detector. In the past fifteen years a lot of experience has been gained in operating and calibrating this instrument. In this presentation we report on the calibration methods and status, new instrumental modes and detector performance, which were acquired and developed based on the in-flight experiences with the instrument. Selecting the proper operating modes, combined with careful data processing based on target characteristics and science goals, allows detection of weak spectral features, despite slowly degrading detectors due to radiation damage and contamination. At present the instrument has excellent health status and performance, and will be one of the few major instruments for X–ray spectroscopy in the coming years, until supplemented by new missions like ASTRO-H and, in particular, Athena.

Genuine teamwork was a key ingredient of the success of the Chandra x-ray observatory mission. Examples are the science center personnel working as part of the instrument principal investigators (IPI) teams during pre-launch development, the Smithsonian Astrophysical Observatory (SAO) supporting NASA/Marshall Space Flight Center (MSFC) by directly working with the prime contractor, TRW (now Northrop Grumman Aerospace Systems), and TRW acceptance of outside scientists performing the data reduction and analysis for qualification of the aspect camera. An end-to-end thread was defined early on, based on the MSFC/SAO operation of the Einstein observatory x-ray telescope, and covered the cycle from solicitation and peer review of observation proposals through scheduling to data processing and delivery. An open science working group chaired by MSFC included instrument principal investigators and interdisciplinary scientists spanning diverse astrophysical and instrumental expertise.

The National Aeronautics and Space Administration recently released the NASA Strategic Plan 2014¹, and the NASA Science Mission Directorate released the NASA 2014 Science Plan³. These strategic documents establish NASA’s astrophysics strategic objectives to be (i) to discover how the universe works, (ii) to explore how it began and evolved, and (iii) to search for life on planets around other stars. The multidisciplinary nature of astrophysics makes it imperative to strive for a balanced science and technology portfolio, both in terms of science goals addressed and in missions to address these goals. NASA uses the prioritized recommendations and decision rules of the National Research Council’s 2010 decadal survey in astronomy and astrophysics² to set the priorities for its investments. The NASA Astrophysics Division has laid out its strategy for advancing the priorities of the decadal survey in its Astrophysics 2012 Implementation Plan⁴. With substantial input from the astrophysics community, the NASA Advisory Council’s Astrophysics Subcommittee has developed an astrophysics visionary roadmap, Enduring Quests, Daring Visions⁵, to examine possible longer-term futures. The successful development of the James Webb Space Telescope leading to a 2018 launch is an Agency priority. One important goal of the Astrophysics Division is to begin a strategic mission, subject to the availability of funds, which follows from the 2010 decadal survey and is launched after the James Webb Space Telescope. NASA is studying a Wide Field Infrared Survey Telescope as its next large astrophysics mission. NASA is also planning to partner with other space agencies on their missions as well as increase the cadence of smaller Principal Investigator led, competitively selected Astrophysics Explorers missions.

Canada became actively engaged in space astronomy in the 1990s by contributing two fine guidance sensors to the FUSE Far-UV mission (NASA 1999-2008). In the same period, Canada contributed to ODIN’s infrared instrument (ESA 2001-2006) and correlators for VSOP (JAXA 1997-2005). In early 2000, Canada developed its own space telescope, Micro-variability and Observations of STars (MOST), a 15-cm telescope on a microsatellite, operating since 2003, and more recently contributed to the realization of the BRITE nanosatellites constellation. Canada also provided hardware to the European Space Agency’s Herschel HIFI instrument and simulators to the SPIRE instrument and data analysis tools for Planck. More recently the Canadian Space Agency (CSA) delivered detector units for the UVIT instrument on board the Indian Space Research Organisation’s (ISRO) ASTROSAT. The CSA’s most important contribution to a space astronomy mission to date is the Fine Guidance Senor (FGS) and Near Infrared Imager and Slitless Spectrograph (NIRISS) instrument to NASA’s James Webb Space Telescope. The CSA is currently building the laser metrology system for JAXA’s ASTRO-H hard X-ray telescope. Canadian astronomers contributed to several high profile stratospheric balloon projects investigating the CMB and the CSA recently established a balloon launch facility. As expressed in Canada’s new Space Policy Framework announced in February 2014, Canada remains committed to future space exploration endeavors. The policy aims at ensure that Canada is a sought-after partner in the international space exploration missions that serve Canada’s national interests; and continuing to invest in the development of Canadian contributions in the form of advanced systems and optical instruments. In the longer term, through consultations and in keeping the Canadian astronomical community’s proposed Long Range Plan, the CSA is exploring possibilities to contributions to important missions such as WFIRST, SPICA and Athena and in other areas, by initiating concept and pre-mission studies and enabling technology developments. These reflect the following scientific priorities identified: dark energy and the accelerating universe, addressed by large survey missions; high-energy astrophysics, which includes UV and X-ray missions; and the understanding of star formation and proto-planetary systems and to begin characterizing exoplanets, mainly by infra-red space observatories.

The High Energy cosmic-Radiation Detection (HERD) facility is one of several space astronomy payloads of the cosmic lighthouse program onboard China's Space Station, which is planned for operation starting around 2020 for about 10 years. The main scientific objectives of HERD are indirect dark matter search, precise cosmic ray spectrum and composition measurements up to the knee energy, and high energy gamma-ray monitoring and survey. HERD is composed of a 3-D cubic calorimeter (CALO) surrounded by microstrip silicon trackers (STKs) from five sides except the bottom. CALO is made of about 10⁴ cubes of LYSO crystals, corresponding to about 55 radiation lengths and 3 nuclear interaction lengths, respectively. The top STK microstrips of seven X-Y layers are sandwiched with tungsten converters to make precise directional measurements of incoming electrons and gamma-rays. In the baseline design, each of the four side SKTs is made of only three layers microstrips. All STKs will also be used for measuring the charge and incoming directions of cosmic rays, as well as identifying back scattered tracks. With this design, HERD can achieve the following performance: energy resolution of 1% for electrons and gamma-rays beyond 100 GeV, 20% for protons from 100 GeV to 1 PeV; electron/proton separation power better than 10^-5; effective geometrical factors of >3 m²sr for electron and diffuse gamma-rays, >2 m²sr for cosmic ray nuclei. R and D is under way for reading out the LYSO signals with optical fiber coupled to image intensified CCD and the prototype of one layer of CALO.

In this paper, we present our developments on micro-calorimeter arrays, based on High Impedance Silicon sensors (MIS or resistive TES) micro-calorimeters and GaAS-GaAlAs HEMTs / SiGe cryo-electronics, started 5 years ago. We show the pixel design, the main steps to build a 32x32 array. We are presently developing two kinds of high impedance sensors: Metal-Insulator-Sensors and High Resistivity Transition Edge Sensors. We described our associated FrontEnd electronics and detailed system level analysis of the foreseen camera. We discuss why we will be able to handle a camera with a large number of pixels (thanks to excellent thermal insulation and no electronic power consuming at the 50mK stage). We discuss the main technological building blocks (Absorber, Sensor) and their present status.

The WFI instrument of ATHENA will provide large field of view in combination with high count-rate capability to address key questions of modern astrophysics. It will utilize a DEPFET based active pixel sensor as focal plane detector. To achieve fastest timings, these sensors can be operated by addressing a region of interest. While this window mode operation enhances time resolution, the probability to collect events during signal processing will become non negligible. Due to the incomplete signal evaluation, these so called misfit events cause an additional background contribution, which will be dominant at very fast timings as required for ATHENA. To sustain the spectral performance a built-in electronic shutter and an intermediate storage can be implemented into each pixel. While the shutter is capable to effectively suppress misfit collection and thus maintains the spectral performance, the implementation of a storage region diminishes possible dead times and improves throughput. We will present measurements on prototype devices demonstrating the benefit of a fast built-in shutter for DEPFET devices operated at high frame rates. Furthermore we will show results of first measurements on structures that combine a built-in shutter with an intermediate storage, obviating dead times and simultaneously improving the spectral response.

We have been developing monolithic active pixel sensors, known as Kyoto’s X-ray SOIPIXs, based on the CMOS SOI (silicon-on-insulator) technology for next-generation X-ray astronomy satellites. The event trigger output function implemented in each pixel offers microsecond time resolution and enables reduction of the non-X-ray background that dominates the high X-ray energy band above 5–10 keV. A fully depleted SOI with a thick depletion layer and back illumination offers wide band coverage of 0.3–40 keV. Here, we report recent progress in the X-ray SOIPIX development. In this study, we achieved an energy resolution of 300 eV (FWHM) at 6 keV and a read-out noise of 33 e- (rms) in the frame readout mode, which allows us to clearly resolve Mn-Kα and Kβ. Moreover, we produced a fully depleted layer with a thickness of 500 μm. The event-driven readout mode has already been successfully demonstrated.

The Russian Space Research Institute (IKI) has developed CdTe detectors for the focal plane of the ART-XC/SRG instrument. The CdTe crystal has dimensions about 30 × 30 × 1 mm. Top and bottom sides of the detector each contain 48 strips and a guard ring. The ASIC VA64TA1 is connected to the CdTe crystal by AC-coupling for both DSSD sides. This approach allows one to have the same ground level for both electronic parts and to operate detectors with different leakage currents without reconfiguration of the VA64TA1 chips. One CdTe crystal and two ASICs are integrated with thermal sensors and Peltier cooler in a big hybrid integrated circuit. This detector is hermetically sealed by a cover with beryllium window. For ground testing the detector volume is filled with dry nitrogen. Peltier cooler is used during ground tests only. Together with the hermetic case package it allows us to operate the detector at low temperature during all ART-XC telescope development tests. When in space, the detector cooling will be provided by a radiator and heat pipes. Polarization rate temperature and voltage dependences as well as splitting charges between electrodes are being studied. IKI manufactured dozen X-ray cameras with detectors and supporting electronics for EM, QM and flight model of the ART-XC telescope. Spectroscopic and imaging performances of the detectors were tested on the IKI’s X-Ray Calibration Facility. Current status of the focal plane detector development and testing will be presented.

Space-based gamma-ray and neutron detectors face strict constraints of mass, volume, and power, and must endure harsh operating environments. Scintillator materials have a long history of successful operation under these conditions, and new materials offer greatly improved performance in terms of efficiency, time response, and energy resolution. The use of scintillators in space remains constrained, however, by the mass, volume, and fragility of the associated light readout device, typically a vacuum photomultiplier tube (PMT). Recently developed silicon photomultipliers (SiPMs) offer gains and efficiencies similar to those of PMTs, but with greatly reduced mass and volume, high ruggedness, and no high-voltage requirements. We have therefore been investigating the use of SiPM readouts for scintillator gamma-ray and neutron detectors, with an emphasis on their suitability for space-based instruments for astrophysics and heliophysics. We present preliminary radiation hardness tests of two promising SiPM devices, and describe two concepts for SiPM-based instruments: an advanced scintillator-based Compton telescope, and a double-scatter neutron telescope suitable for measuring fast solar and magnetospheric neutrons. Supporting laboratory measurements are presented to demonstrate the feasibility of these telescope concepts.

Future x-ray astronomical missions require x-ray mirror assemblies that provide both high angular resolution and large photon collecting area. In addition, as x-ray astronomy undertakes more sensitive sky surveys, a large field of view is becoming increasingly important as well. Since implementation of these requirements must be carried out in broad political and economical contexts, any technology that meets these performance requirements must also be financially affordable and can be implemented on a reasonable schedule. In this paper we report on progress of an x-ray optics development program that has been designed to address all of these requirements. The program adopts the segmented optical design, thereby is capable of making both small and large mirror assemblies for missions of any size. This program has five technical elements: (1) fabrication of mirror substrates, (2) coating, (3) alignment, (4) bonding, and (5) mirror module systems engineering and testing. In the past year we have made progress in each of these five areas, advancing the angular resolution of mirror modules from 10.8 arc-seconds half-power diameter reported (HPD) a year ago to 8.3 arc-seconds now. These mirror modules have been subjected to and passed all environmental tests, including vibration, acoustic, and thermal vacuum. As such this technology is ready for implementing a mission that requires a 10-arc-second mirror assembly. Further development in the next two years would make it ready for a mission requiring a 5-arc-second mirror assembly. We expect that, by the end of this decade, this technology would enable the x-ray astrophysical community to compete effectively for a major x-ray mission in the 2020s that would require one or more 1-arc-second mirror assemblies for imaging, spectroscopic, timing, and survey studies.

Future X-ray telescopes with very large collecting area, like the proposed Athena with more than 2 m2 effective area at 1 keV, need to be realized as assemblies of a large number of X-ray optical units, named X-ray Optical Units (XOUs). The Brera Astronomical Observatory (INAF-OAB) is developing a new technology to manufacture these modular elements, compatible with an angular resolution of 5 arcsec HEW (Half-Energy-Width). This technique consists in stacking in a Wolter-I configuration several layers of thin foils of glass, previously formed by direct hot slumping. The achievable global angular resolution of the optics relies on the required surface shape accuracy of slumped foils, on the smoothness of the mirror surfaces and on the correct integration and co-alignment of the mirror segments operated trough a dedicated Integration Machine (IMA). In this paper we provide an overview of the project development, reporting on the very promising results achieved so far, including in-focus full illumination X-ray tests of the prototype (Proof of Concept, POC#2, integrated at the beginning of 2013) for which an HEW of 22.1’’ has been measured at Panter/MPE. Moreover we report on the on-going activities, with a new integrated prototype (PoC#3). X-ray test in pencil beam revealed that at least a segment between two external ribs is characterized by an HEW well below 10’’. Lastly, the overall process up-grade to go from 20 m to 12m focal length (to be compatible with Athena+ configuration) is presented.

Optical design trades are underway at the Goddard Space Flight Center to define a telescope for an x-ray survey mission. Top-level science objectives of the mission include the study of x-ray transients, surveying and long-term monitoring of compact objects in nearby galaxies, as well as both deep and wide-field x-ray surveys. In this paper we consider Wolter, Wolter-Schwarzschild, and modified Wolter-Schwarzschild telescope designs as basic building blocks for the tightly nested survey telescope. Design principles and dominating aberrations of individual telescopes and nested telescopes are discussed and we compare the off-axis optical performance at 1.0 KeV and 4.0 KeV across a 1.0 degree full field-of-view.

We discuss necessary improvements and further studies relevant to the design and eventual implementation of an accurately modeled multilayer coated X-ray optic operating in the hard X-ray/soft gamma-ray regime. The process improvements are substantiated through lessons learnt from NuSTAR.

Soft x-ray spectroscopy of celestial sources with high resolving power R = E/ΔE and large collecting area addresses important science listed in the Astro2010 Decadal Survey New Worlds New Horizons, such as the growth of the large scale structure of the universe and its interaction with active galactic nuclei, the kinematics of galactic outflows, as well as coronal emission from stars and other topics. Numerous studies have shown that a transmission grating spectrometer based on lightweight critical-angle transmission (CAT) gratings can deliver R = 3000-5000 and large collecting area with high efficiency and minimal resource requirements, providing spectroscopic figures of merit at least an order of magnitude better than grating spectrometers on Chandra and XMM-Newton, as well as future calorimeter-based missions. The recently developed CAT gratings combine the advantages of transmission gratings (low mass, relaxed figure and alignment tolerances) and blazed reflection gratings (high broad band diffraction efficiency, utilization of higher diffraction orders). Their working principle based on blazing through reflection off the smooth, ultra-high aspect ratio grating bar sidewalls has previously been demonstrated on small samples with x rays. For larger gratings (area greater than 1 inch square) we developed a fabrication process for grating membranes with a hierarchy of integrated low-obscuration supports. The fabrication involves a combination of advanced lithography and highly anisotropic dry and wet etching techniques. We report on the latest fabrication results of free-standing, large-area CAT gratings with polished sidewalls and preliminary x-ray tests.

Large X-ray telescopes for future observations need to combine a big collecting area with good angular resolution. Due to the mass limits of the launching rocket, light-weight materials are needed in order to enhance the collecting area in future telescopes. We study the development of mirror segments made from thin glass sheets which are shaped by thermal slumping. At MPE we follow the indirect approach which enables us the production of the parabolic and hyperbolic part of the Wolter type I mirrors in one piece. In our recent research we have used a test mould made of CeSiC™ for slumping processes in our lab furnace as well as in a heatable vacuum chamber, to avoid oxidation and air enclosure. Additional slumping tests in the vacuum furnace have been carried out using a Kovar mould and are compared with results under air. We describe the experimental set-up, the slumping process and the metrology methods and give an outlook on future activities.

Post-mounting figure correction is a promising avenue to produce low-mass, high-resolution X-ray telescopes. We have demonstrated the feasibility of this approach using piezoelectrically adjustable glass mirrors. Influence functions for various piezoelectric cells have previously been measured with an optical profilometer, but with significant noise. We have improved on both the speed and accuracy of these measurements using a Shack- Hartmann wavefront sensing system. Additionally, we have altered our wavefront sensing system to investigate the mid frequency roughness of our slumped glass mirrors. We report on initial results for measurements of both influence functions and mid frequency roughness and describe our path forward.

X-ray Timing and Polarization (XTP) satellite, by using focusing optics and advanced detector technology, is dedicated to the study of Black Hole, Neutron Star, Quark Star and the physics under extreme gravity, density and magnetism. With a detection area of ~1 square meter and a combination of various types of X-ray telescopes, XTP is expected to make the most sensitive temporal and polarization observations with good energy resolution in 1-30 keV. We present a recent overview on segmented glass optics for XTP Telescope. This work is looking for improvement of the figure of the free-standing glass substrates, enhancement of quality of grazing incident depth-graded multilayers and a mounting technology for the substrates. We discuss metrology on glass figure, X-ray reflectivity and scatter of grazing incident depth-graded multilayers, and mounted structured optics. We also present plans for several prototype optics to be constructed in the upcoming year. Begin the abstract two lines below author names and addresses. The abstract summarizes key findings in the paper.

Over the last few decades, grazing incidence X-ray optics have been a pivotal tool for advances in X-ray astronomy. They have been successfully employed in many great observatories such as ROSAT, Chandra X-ray Observatory and XMM-Newton. In planetary science, X-ray observations of Solar system objects are a great tool to understand the nature of the target bodies and the evolutionary history of the Solar system as a whole. To date, X-ray observations in near-target planetary missions have been limited to collimator-based instruments due to tight mass and volume constraints, arising from the multi-instrument nature of planetary missions. In addition, unlike observations of astrophysical sources at virtually infinite distances, near-target observations of planetary bodies introduce a unique set of challenges. While true focusing X-ray optics can overcome these challenges, a practical implementation of focusing X-ray optics for planetary missions depends on the feasibility of compact lightweight X-ray optics. We review scientific motivations for X-ray observations of planetary bodies and illustrate the unique challenges encountered in planetary missions through a few examples. We introduce a new metal-ceramic hybrid technology for X-ray mirrors that can enable compact lightweight Wolter-I X-ray optics suitable for resource limited planetary missions.

NASA’S future X-ray astronomy missions will require X-ray optics that have large effective area while remaining lightweight, and cost effective. Some X-ray missions, such as XMM-Newton[1] , and the upcoming Spectrum-Röntgen- Gamma[2] mission use an electroformed nickel replication (ENR) process[3] to fabricate the nested grazing incidence X-ray telescope mirror shells for an array of moderate resolution, moderate effective area telescopes. We are developing a process to fabricate metal-ceramic replicated optics which will be lighter weight than current nickel replicated technology. Our technology development takes full advantage of the replication technique by fabricating large diameter mirrors with thin cross sections allowing maximum nesting and increase in collecting area. This will lead to future cost effective missions with large effective area and lightweight optics with good angular resolution. Recent results on fabrication and testing of these optics is presented.

The primary science goal of the Polarimeters for Energetic Transients (POET) mission is to measure the polarization of gamma-ray bursts over a wide energy range, from X rays to soft gamma rays. The higher-energy portion of this band (50 - 500 keV) will be covered by the High Energy Polarimeter (HEP) instrument, a non-imaging, wide field of view Compton polarimeter. Incident high-energy photons will Compton scatter in low-Z, plastic scintillator detector elements and be subsequently absorbed in high-Z, CsI(Tl) scintillator elements; polarization is detected by measuring an asymmetry in the azimuthal scatter angle distribution. The HEP design is based on our considerable experience with the development and flight of the Gamma-Ray Polarimeter Experiment (GRAPE) balloon payload. We present the design of the POET HEP instrument, which incorporates lessons learned from the GRAPE balloon design and previous work on Explorer proposal efforts, and its expected performance on a two-year SMEX mission.

WPOL (Wide field camera with POLarimetry) is a wide field camera which aims to monitor the X-ray/low gamma-ray sources and measures their polarimetric properties. This camera will be operated in space to trigger a main instrument in case of transient events (gamma-ray bursts, black hole binaries state transition, supernovae, …) and to map the Xray/ gamma-ray polarized sources of the Galaxy, which has never been done up to now. It will be proposed, as an accompanying instrument, in the context of the next medium mission ESA call (M4). The concept of the instrument is based upon a coded mask imaging with a detector unit composed of two planes of Silicon double sided stripped detectors (DSSD), a passive collimator and a tungsten mask. Mapping is done on the first plane through mask imaging and polarization is measured by studying Compton scattering events between the two planes. The source direction in the sky being known through the mask pattern projected on the detector plane, and the scattered photon direction being measured between the two planes, only the determination of the first energy deposit is needed to compute the whole Compton scattering kinetics and in particular, to determine the source photon energy

ABSTRACT We present continued development of laterally graded multilayer mirrors (LGMLs) for a telescope design capable of measuring linear X-ray polarization over a broad spectral band. The multilayer-coated mirrors are used as Bragg re ectors at the Brewster angle. By matching to the dispersion of a spectrometer, one may take advantage of high multilayer re ectivities and achieve modulation factors over 50% over the entire 0.2-0.8 keV band. In Phase II of the polarimetry beam-line development, we demonstrated that the system provides 100% polarized X-rays at 0.525 keV (Marshall et al. 2013). Here, we present results from phase III of our development, where a LGML is used at the source and laterally manipulated in order to select and polarize X-rays from emission lines for a variety of source anodes. The beam-line will then provide the capability to test polarimeter components across the 0.15-0.70 keV band. We also present plans for a suborbital rocket experiment designed to detect a polarization level of better than 10% for an active galactic nucleus.

X-ray Timing and Polarization (XTP) mission will use focusing optics and advanced detector technology to be dedicated to the study of Black Hole, Neutron Star, Quark Star and the physics under extreme gravity, density and magnetism. XTP is expected to make the most sensitive temporal and polarization observations with good energy resolution in 1-30 keV with a detection area of ~1 square meter and a combination of various types of X-ray telescopes. We present a recent overview on the depth-graded multilayers coated on segmented glass optics used in XTP Telescope. This presentation will focus on improving the design, fabrication and characterization of grazing incident depth-graded multilayers based on the requirements of XTP. We discuss metrology on X-ray reflectivity and scatter of grazing incident depth-graded multilayers. We also present the future plan of making more depth-graded multilayers on thermally-slumped glass uesd in several prototype optics.

A gas Time Projection Chamber can be used for gamma-ray astronomy with excellent angular-precision and sensitivity to faint sources, and for polarimetry, through the measurement of photon conversion to e⁺e⁻ pairs. We present the expected performance in simulations and the recent development of a demonstrator for tests in a polarized photon beam.

The design of the Time-Projection Chamber (TPC) Polarimeter for the Gravity and Extreme Magnetism Small Explorer (GEMS) was demonstrated to Technology Readiness Level 6 (TRL-6)³ and the flight detectors fabricated, assembled and performance tested. A single flight detector was characterized at the Brookhaven National Laboratory Synchrotron Light Source with polarized X-rays at 10 energies from 2.3–8.0 keV at five detector positions. The detector met all of the GEMS performance requirements. Lifetime measurements have shown that the existing flight design has 23 years of lifetime⁴, opening up the possibility of relaxing material requirements, in particular the consideration of the use of epoxy, to reduce risk elsewhere. We report on design improvements to the GEMS detector to enable a narrower transfer gap that, when operated with a lower transfer field, reduces asymmetries in the detector response. In addition, the new design reduces cost and risk by simplifying the assembly and reducing production time. Finally, we report on the performance of the narrow-gap detector in response to polarized and unpolarized X-rays.

Monitor of All-sky X-ray Image (MAXI) is mounted on the International Space Station (ISS). Since 2009 it has been scanning the whole sky in every 92 minutes with ISS rotation. Due to high particle background at high latitude regions the carbon anodes of three GSC cameras were broken. We limit the GSC operation to low-latitude region around equator. GSC is suffering a double high background from Gamma-ray altimeter of Soyuz spacecraft. MAXI issued the 37-month catalog with 500 sources above ~0.6 mCrab in 4-10 keV. MAXI issued 133 to Astronomers Telegram and 44 to Gammaray burst Coordinated Network so far. One GSC camera had a small gas leak by a micrometeorite. Since 2013 June, the 1.4 atm Xe pressure went down to 0.6 atm in 2014 May 23. By gradually reducing the high voltage we keep using the proportional counter. SSC with X-ray CCD has detected diffuse soft X-rays in the all-sky, such as Cygnus super bubble and north polar spur, as well as it found a fast soft X-ray nova MAXI J0158-744. Although we operate CCD with charge-injection, the energy resolution is degrading. In the 4.5 years of operation MAXI discovered 6 of 12 new black holes. The long-term behaviors of these sources can be classified into two types of the outbursts, 3 Fast Rise Exponential Decay (FRED) and 3 Fast Rise and Flat Top (FRFT). The cause of types is still unknown.

The Nuclear Spectroscopic Telescope Array (NuSTAR) mission was launched on 2012 June 13 and is the first focusing high-energy X-ray telescope in orbit operating above ~10 keV. NuSTAR flies two co-aligned Wolter-I conical approximation X-ray optics, coated with Pt/C and W/Si multilayers, and combined with a focal length of 10.14 meters this enables operation from 3-79 keV. The optics focus onto two focal plane arrays, each consisting of 4 CdZnTe pixel detectors, for a field of view of 12.5 arcminutes. The inherently low background associated with concentrating the X-ray light enables NuSTAR to probe the hard X-ray sky with a more than 100-fold improvement in sensitivity, and with an effective point spread function FWHM of 18 arcseconds (HPD ~1), NuSTAR provides a leap of improvement in resolution over the collimated or coded mask instruments that have operated in this bandpass. We present in-orbit performance details of the observatory and highlight important science results from the first two years of the mission.

We present results of the point spread function (PSF) calibration of the hard X-ray optics of the Nuclear Spectroscopic Telescope Array (NuSTAR). Immediately post-launch, NuSTAR has observed bright point sources such as Cyg X-1, Vela X-1, and Her X-1 for the PSF calibration. We use the point source observations taken at several off-axis angles together with a ray-trace model to characterize the in-orbit angular response, and find that the ray-trace model alone does not fit the observed event distributions and applying empirical corrections to the ray-trace model improves the fit significantly. We describe the corrections applied to the ray-trace model and show that the uncertainties in the enclosed energy fraction (EEF) of the new PSF model is (approximately less than) 3% for extraction apertures of R (approximately greater than) 60″ with no significant energy dependence. We also show that the PSF of the NuSTAR optics has been stable over a period of ~300 days during its in-orbit operation.

The Nuclear Spectroscopic Telescope Array (NuSTAR) satellite is a NASA Small Explorer mission designed to operate the first focusing high-energy X-ray (3-79 keV) telescope in orbit. Since the launch in June 2012, all the NuSTAR components have been working normally. The focal plane module is equipped with an 155Eu radioactive source to irradiate the CdZnTe pixel detectors for independent calibration separately from optics. The inflight spectral calibration of the CdZnTe detectors is performed with the onboard 155Eu source. The derived detector performance agrees well with ground-measured data. The in-orbit detector background rate is stable and the lowest among past high-energy X-ray instruments.

ASTROSAT is India’s first astronomy satellite that will carry an array of instruments capable of simultaneous observations in a broad range of wavelengths: from the visible, near ultraviolet (NUV), far-UV (FUV), soft X-rays to hard X-rays. There will be five principal scientific payloads aboard the satellite: (i) a Soft X-ray Telescope (SXT), (ii) three Large Area Xenon Proportional Counters (LAXPCs), (iii) a Cadmium-Zinc-Telluride Imager (CZTI), (iv) two Ultra-Violet Imaging Telescopes (UVITs) one for visible and near-UV channels and another for far-UV, and (v) three Scanning Sky Monitors (SSMs). It will also carry a charged particle monitor (CPM). Almost all the instruments have qualified and their flight models are currently in different stages of integration into the satellite structure in ISRO Satellite Centre. ASTROSAT is due to be launched by India’s Polar Satellite Launch Vehicle (PSLV) in the first half of 2015 in a circular 600 km orbit with inclination of ~6 degrees, from Sriharikota launching station on the east coast of India. A brief description of the design, construction, capabilities and scientific objectives of all the main scientific payloads is presented here. A few examples of the simulated observations with ASTROSAT and plans to utilize the satellite nationally and internationally are also presented.

eROSITA (extended ROentgen Survey with an Imaging Telescope Array) is the core instrument on the Russian/German Spektrum-Roentgen-Gamma (SRG) mission which is now officially scheduled for launch on March 26, 2016. eROSITA will perform a deep survey of the entire X-ray sky. In the soft band (0.5-2 keV), it will be about 30 times more sensitive than ROSAT, while in the hard band (2-8 keV) it will provide the first ever true imaging survey of the sky. The design driving science is the detection of large samples of galaxy clusters to redshifts z < 1 in order to study the large scale structure in the universe and test cosmological models including Dark Energy. In addition, eROSITA is expected to yield a sample of a few million AGN, including obscured objects, revolutionizing our view of the evolution of supermassive black holes. The survey will also provide new insights into a wide range of astrophysical phenomena, including X-ray binaries, active stars and diffuse emission within the Galaxy. eROSITA is currently (June 2014) in its flight model and calibration phase. All seven flight mirror modules (+ 1 spare) have been delivered and measured in X-rays. The first camera including the complete electronics has been extensively tested (vacuum + X-rays). A pre-test of the final end-toend test has been performed already. So far, all subsystems and components are well within their expected performances.

Spectrum Roentgen Gamma (SRG) is an X-ray astrophysical observatory, developed by Russia in collaboration with Germany. The mission will be launched in March 2016 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 softx- 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. The NASA Marshall Space Flight Center (MSFC) is fabricating the flight mirror modules for the ART-XC/SRG. Each mirror module will be aligned with a focal plane CdTe double-sided strip detector which will operate over the energy range of 6−30 keV, with an angular resolution of <1′, a field of view of ~34′ and an expected energy resolution of about 10% at 14 keV.

The Astronomical Roentgen Telescope (ART) instrument is a hard-x-ray instrument with energy response up to 30 keV that is to be launched on board of the Spectrum Roentgen Gamma (SRG) Mission. The instrument consists of seven identical mirror modules coupled with seven CdTe strip focal-plane detectors. The mirror modules are being developed at the Marshall Space Flight Center (MSFC.) Each module has ~65 sq. cm effective area and an on-axis angular resolution of 30 arcseconds half power diameter (HPD) at 8 keV. The current status of the mirror module development and testing will be presented.

The eROSITA space telescope is currently developed for the determination of cosmological parameters and the equation of state of dark energy via evolution of clusters of galaxies. Furthermore, the instrument development was strongly motivated by the intention of a first imaging X-ray all-sky survey enabling measurements above 2 keV. eROSITA is a scientific payload on the Russian research satellite SRG. Its destination after launch is the Lagrangian point L2. The observational program of the observatory divides into an all-sky survey and pointed observations and takes in total about 7.5 years. The instrument comprises an array of 7 identical and parallel aligned telescopes. Each of the seven focal plane cameras is equipped with a PNCCD detector, an enhanced type of the XMM-Newton focal plane detector. This instrumentation permits spectroscopy and imaging of X-rays in the energy band from 0.3 keV to 10 keV with a field of view of 1.0 degree. The camera development is done at the Max-Planck-Institute for extraterrestrial physics. Key component of each camera is the PNCCD chip. This silicon sensor is a back-illuminated, fully depleted and column-parallel type of charge coupled device. The image area of the 450 micron thick frame-transfer CCD comprises an array of 384 x 384 pixels, each with a size of 75 micron x 75 micron. Readout of the signal charge that is generated by an incident X-ray photon in the CCD is accomplished by an ASIC, the so-called eROSITA CAMEX. It provides 128 parallel analog signal processing channels but multiplexes the signals finally to one output which feeds the detector signals to a fast 14-bit ADC. The read noise of this system is equivalent to a noise charge of about 2.5 electrons rms. We achieve an energy resolution close to the theoretical limit given by Fano noise (except for very low energies). For example, the FWHM at an energy of 5.9 keV is approximately 140 eV. The complete camera assembly comprises the camera head with the detector as key component, the electronics for detector operation as well as data acquisition and the filter wheel unit. In addition to the on-chip light blocking filter directly deposited on the photon entrance window of the PNCCD, an external filter can be moved in front of the sensor, which serves also for contamination protection. Furthermore, an on-board calibration source emitting several fluorescence lines is accommodated on the filter wheel mechanism for the purpose of in-orbit calibration. Since the spectroscopic silicon sensors need cooling down to -95°C to mitigate best radiation damage effects, an elaborate cooling system is necessary. It consists of two different types of heat pipes linking the seven detectors to two radiators. Based on the tests with an engineering model, a flight design was developed for the camera and a qualification model has been built. The tests and the performance of this camera is presented in the following. In conclusion an outlook on the flight cameras is given.

In 2016 the X-ray Survey Telescope eROSITA, designed and built at MPE, will be launched on the Russian Spektr- Roentgen-Gamma Mission. A compact bundle of 7 co-aligned mirror modules with a focal length of 1600 mm and 54 nested mirror shells each form the X-ray telescope. The sensitivity of the telescope in terms of effective area, field-ofview (61'), and angular resolution (~16" HEW on-axis) will yield a high grasp of about 1000 cm² deg² around 1 keV with an average angular resolution of ~26" HEW over the field-of-view (30" including optical and spacecraft error contributions). All flight mirror modules including a flight spare have been completed and passed their acceptance tests in December 2013. The mirror modules now have all been mated with their corresponding X-ray baffles to form mirror assemblies and the passed rigorous environmental vibration and thermal cycling tests. Here we report on the results of these measurements and on the calibration measurements planned for the completed flight mirror assemblies.

We report our recent activities for a development of a new X-ray interferometer with a beam splitter and discuss a possible observation of some celestial objects. The X-ray interferometer consists of two flat mirrors and one flat beam splitter. Samples of the beam splitter and the mirrors have been designed and fabricated. We measured the reflectivity of the mirrors and the reflectivity and transmission of the beam splitters with a synchrotron source at KEK-PF. Obtained results of the mirrors are roughly consistent with the design values, but the reflectivity of the beam splitter is roughly half of the design value. Using these measured values, we estimated required area and observation-time to obtain fringe signals of celestial objects. We concluded that a broad-band interferometer using non-dispersive high spectral resolution detector, such as the micro-calorimeter array, is essential for the future development.

Over a 10-month period during 2013 and early 2014, development of the Neutron star Interior Composition Explorer (NICER) mission [1] proceeded through Phase B, Mission Definition. An external attached payload on the International Space Station (ISS), NICER is scheduled to launch in 2016 for an 18-month baseline mission. Its prime scientific focus is an in-depth investigation of neutron stars—objects that compress up to two Solar masses into a volume the size of a city—accomplished through observations in 0.2–12 keV X-rays, the electromagnetic band into which the stars radiate significant fractions of their thermal, magnetic, and rotational energy stores. Additionally, NICER enables the Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) demonstration of spacecraft navigation using pulsars as beacons. During Phase B, substantive refinements were made to the mission-level requirements, concept of operations, and payload and instrument design. Fabrication and testing of engineering-model components improved the fidelity of the anticipated scientific performance of NICER’s X-ray Timing Instrument (XTI), as well as of the payload’s pointing system, which enables tracking of science targets from the ISS platform. We briefly summarize advances in the mission’s formulation that, together with strong programmatic performance in project management, culminated in NICER’s confirmation by NASA into Phase C, Design and Development, in March 2014.

The Hard X-ray Modulation Telescope (HXMT) is China’s first astronomical satellite. Based on the Direct Demodulation Method (DDM), it was designed to reconstructs images from data obtained in a scanning mode. Although this project was delayed by about 15 years, it will still bring us merits in some key sciences of observing the galactic transients and measuring the diffuse X-ray emission. This satellite is currently in the phase of flight model production with the expected launch in late 2015.

The SVOM (Space-based multi-band astronomical Variable Objects Monitor) French-Chinese mission is dedicated to the detection, localization and study of Gamma Ray Bursts (GRBs) and other high-energy transient phenomena. We first present the major principles of the SVOM system including the alert system providing near-real-time GRB localizations to large ground-based telescopes. Then the paper describes the definition of the SVOM payload and more particularly the French payload composed of the ECLAIRs instrument, dedicated to GRB detection and positioning, and the MXT instrument, dedicated to GRB followup observation in soft X-ray band.

We present the Microchannel X-ray Telescope, a new light and compact focussing telescope that will be ying on the Sino-French SVOM mission dedicated to Gamma-Ray Burst science. The MXT design is based on the coupling of square pore micro-channel plates with a low noise pnCCD. MXT will provide an effective area of about 50 cm², and its point spread function is expected to be better than 3.7 arc min (FWHM) on axis. The estimated sensitivity is adequate to detect all the afterglows of the SVOM GRBs, and to localize them to better then 60 arc sec after five minutes of observation.

We present ECLAIRs, the Gamma-ray burst (GRB) trigger camera to fly on-board the Chinese-French mission SVOM. ECLAIRs is a wide-field (~ 2 sr) coded mask camera with a mask transparency of 40% and a 1024 cm² detection plane coupled to a data processing unit, so-called UGTS, which is in charge of locating GRBs in near real time thanks to image and rate triggers. We present the instrument science requirements and how the design of ECLAIRs has been optimized to increase its sensitivity to high-redshift GRBs and low-luminosity GRBs in the local Universe, by having a low-energy threshold of 4 keV. The total spectral coverage ranges from 4 to 150 keV. ECLAIRs is expected to detect ~ 200 GRBs of all types during the nominal 3 year mission lifetime. To reach a 4 keV low-energy threshold, the ECLAIRs detection plane is paved with 6400 4 × 4 mm² and 1 mm-thick Schottky CdTe detectors. The detectors are grouped by 32, in 8×4 matrices read by a low-noise ASIC, forming elementary modules called XRDPIX. In this paper, we also present our current efforts to investigate the performance of these modules with their front-end electronics when illuminated by charged particles and/or photons using radioactive sources. All measurements are made in different instrument configurations in vacuum and with a nominal in-flight detector temperature of −20°C. This work will enable us to choose the in-flight configuration that will make the best compromise between the science performance and the in-flight operability of ECLAIRs. We will show some highlights of this work.

The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions developed by the Institute of Space and Astronautical Science (ISAS), with a planned launch in 2015. The ASTRO-H mission is equipped with a suite of sensitive instruments with the highest energy resolution ever achieved at E > 3 keV and a wide energy range spanning four decades in energy from soft X-rays to gamma-rays. The simultaneous broad band pass, coupled with the high spectral resolution of ΔE ≤ 7 eV of the micro-calorimeter, will enable a wide variety of important science themes to be pursued. ASTRO-H is expected to provide breakthrough results in scientific areas as diverse as the large-scale structure of the Universe and its evolution, the behavior of matter in the gravitational strong field regime, the physical conditions in sites of cosmic-ray acceleration, and the distribution of dark matter in galaxy clusters at different redshifts.

The new Japanese X-ray Astronomy satellite, ASTRO-H will carry two identical hard X-ray telescopes (HXTs), which cover 5 to 80 keV, in order to provide new insights into frontier of X-ray astronomy. The HXT mirror surfaces are coated with Pt/C depth-graded multilayers to enhance hard X-ray effective area by means of Bragg reflection, and 213 mirror reflectors with a thickness of 0.22 mm are tightly nested confocally in a telescope. The production of FM HXT-1 and HXT-2 were completed in 2012 and 2013, respectively. The X-ray performance of HXTs were measured at the synchrotron radiation facility SPring-8/ BL20B2 Japan. The total effective area of two HXTs is about 350 cm² at 30 keV and the angular resolution of HXT is about 1.’9 in half power diameter at 30 keV. The HXTs are in the clean room at ISAS for waiting the final integration test.

The 6th Japanese X-ray satellite, ASTRO-H, is scheduled for launch in 2015. The hard X-ray focusing imaging system will observe astronomical objects with the sensitivity for detecting point sources with a brightness of 1/100,000 times fainter than the Crab nebula at > 10 keV. The Hard X-ray Imager (HXI) is a focal plane detector 12 m below the hard X-ray telescope (HXT) covering the energy range from 5 to 80 keV. The HXI is composed of a stacked Si/CdTe semiconductor detector module and surrounding BGO scintillators. The latter work as active shields for efficient reduction of background events caused by cosmic-ray particles, cosmic X-ray background, and in-orbit radiation activation. In this paper, we describe the detector system, and present current status of flight model development, and performance of HXI using an engineering model of HXI.

ASTRO-H is an astrophysics satellite dedicated for non-dispersive X-ray spectroscopic study on selective celestial X-ray sources. Among the onboard instruments there are four Wolter-I X-ray mirrors of their reflectors’ figure in conical approximation. Two of the four are soft X-ray mirrors¹, of which the energy range is from a few hundred eV to 15 keV within the effective aperture being defined by the nested reflectors’ radius ranging between 5.8 cm to 22.5 cm. The focal point instruments will be a calorimeter (SXS) and a CCD camera (SXI), respectively. The mirrors were in quadrant configuration with photons being reflected consecutively in the primary and secondary stage before converging on the focal plane of 5.6 m away from the interface between the two stages. The reflectors of the mirror are made of heat-formed aluminum substrate of the thickness gauged of 152 μm, 229 μm, and 305 μm of the alloy 5052 H-19, followed by epoxy replication on gold-sputtered smooth Pyrex cylindrical mandrels to acquire the X-ray reflective surface. The epoxy layer is 10 m nominal and surface gold layer of 0.2 μm. Improvements on angular response over its predecessors, e.g. Astro-E1/Suzaku mirrors, come from error reduction on the figure, the roundness, and the grazing angle/radius mismatching of the reflecting surface, and tighter specs and mechanical strength on supporting structure to reduce the reflector positioning and the assembly errors. Each soft x-ray telescope (SXT), SXT-1 or SXT-2, were integrated from four independent quadrants of mirrors. The stray-light baffles, in quadrant configuration, were mounted onto the integrated mirror. Thermal control units were attached to the perimeter of the integrated mirror to keep the mirror within operating temperature in space. The completed instrument went through a series of optical alignment, thus made the quadrant images confocal and their optical axes in parallel to achieve highest throughput possible. Environmental tests were carried out, and optical quality of the telescopes has been confirmed. SXT-1 and -2 were tested with the broad but slightly divergent beam, up to 8 arc-minutes, at Goddard. The full characterization were carried out in Japan which includes: angular resolution, effective area in the energy range of ~ 0.4 – 12keV, off-axis response at various energies, etc. We report the calibration results of the SXT-1 and -2 that were obtained at NASA/Goddard and JAXA/ISAS. The detailed calibration are reported in the two papers in this conference: 9144-206, "Ground-based x-ray calibration of the ASTRO-H soft x-ray telescopes" by R. Iizuka et al. and 9144-207, "Revealing a detailed performance of the soft x-ray telescopes of the ASTRO-H mission" by T. Sato, et al. Some small but significant discrepancies existed between ISAS and Goddard measurements that were attributed to the difference of the X-ray beams - pencil beam vs divergent beam.

Soft X-ray Imager (SXI) is a CCD camera onboard the ASTRO-H satellite which is scheduled to be launched in 2015. The SXI camera contains four CCD chips, each with an imaging area of 31mm x 31 mm, arrayed in mosaic, covering the whole FOV area of 38′ x 38′. The CCDs are a P-channel back-illuminated (BI) type with a depletion layer thickness of 200 _m. 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. Most of the flight components of the SXI system are completed until the end of 2013 and assembled, and an end-to-end test is performed. Basic performance is verified to meet the requirements. Similar performance is confirmed in the first integration test of the satellite performed in March to June 2014, in which the energy resolution at 5.9 keV of 160 eV is obtained. In parallel to these activities, calibrations using engineering model CCDs are performed, including QE, transmission of a filter, linearity, and response profiles.

We present the development status of the Soft X-ray Spectrometer (SXS) onboard the ASTRO-H mission. The SXS provides the capability of high energy-resolution X-ray spectroscopy of a FWHM energy resolution of < 7eV in the energy range of 0.3 – 10 keV. It utilizes an X-ray micorcalorimeter array operated at 50 mK. The SXS microcalorimeter subsystem is being developed in an EM-FM approach. The EM SXS cryostat was developed and fully tested and, although the design was generally confirmed, several anomalies and problems were found. Among them is the interference of the detector with the micro-vibrations from the mechanical coolers, which is the most difficult one to solve. We have pursued three different countermeasures and two of them seem to be effective. So far we have obtained energy resolutions satisfying the requirement with the FM cryostat.

The Soft Gamma-ray Detector (SGD) is one of observational instruments onboard the ASTRO-H, and will provide 10 times better sensitivity in 60{600 keV than the past and current observatories. The SGD utilizes similar technologies to the Hard X-ray Imager (HXI) onboard the ASTRO-H. The SGD achieves low background by constraining gamma-ray events within a narrow field-of-view by Compton kinematics, in addition to the BGO active shield. In this paper, we will present the results of various tests using engineering models and also report the flight model production and evaluations.

The science requirements for the Athena X-ray mirror are to provide a collecting area of 2 m² at 1 keV, an angular resolution of ~5 arc seconds half energy eidth (HEW) and a field of view of diameter 40-50 arc minutes. This combination of area and angular resolution over a wide field are possible because of unique features of the Silicon pore optics (SPO) technology used. Here we describe the optimization and modifications of the SPO technology required to achieve the Athena mirror specification and demonstrate how the optical design of the mirror system impacts on the scientific performance of Athena.

With the selection of “The hot and energetic Universe” as science theme for ESA's second large class mission (L2) in the Cosmic Vision programme, work is focusing on the technology preparation for an advanced X-ray observatory. The core enabling technology for the high performance mirror is the Silicon Pore Optics (SPO) [1 to 23], a modular X-ray optics technology, which utilises processes and equipment developed for the semiconductor industry. The paper provides an overview of the programmatic background, the status of SPO technology and gives an outline of the development roadmap and activities undertaken and planned by ESA on optics, coatings [24 to 30] and test facilities [31, 33].

Silicon Pore Optics, after 10 years of development, forms now the basis for future large (L) class astrophysics Xray observatories, such as the ATHENA mission to study the hot and energetic universe, matching the L2 science theme recently selected by ESA for launch in 2028. The scientific requirements result in an optical design that demands high angular resolution (5“) and large effective area (2 m² at a few keV) of an X-ray lens with a focal length of 12 to14 m. Silicon Pore Optics was initially based on long (25 to 50 m) focal length telescope designs, which could achieve several arc second angular resolution by curving the silicon mirror in only one direction (conical approximation). With the advent of shorter focal length missions we started to develop mirrors having a secondary curvature, allowing the production of Wolter-I type optics, which are on axis aberration-free. In this paper we will present the new manufacturing process, discuss the impact of the ATHENA optics design on the technology development and present the results of the latest X-ray test campaigns.

Silicon Pore Optics (SPO) are the enabling technology for ESA’s second large class mission in the Cosmic Vision programme. As for every space hardware, a critical qualification process is required to verify the suitability of the SPO mirror modules surviving the launch loads and maintaining their performance in the space environment. We present recent design modifications to further strengthen the mounting system (brackets and dowel pins) against mechanical loads. The progress of a formal qualification test campaign with the new mirror module design is shown. We discuss mechanical and thermal limitations of the SPO technology and provide recommendations for the mission design of the next X-ray Space Observatory.

The "Hot and Energetic Universe" has been selected as the science theme for ESA's L2 mission, scheduled for launch in 2028. The proposed Athena X-ray observatory provides the necessary capabilities to achieve the ambitious goals of the science theme. The X-ray mirrors are based on silicon pore optics technology and will have a 12 m focal length. Two complementary camera systems are foreseen which can be moved in and out of the focal plane by an interchange mechanism. These instruments are the actively shielded micro-calorimeter spectrometer X-IFU and the Wide Field Imager (WFI). The WFI will combine an unprecedented survey power through its large field of view of 40 arcmin with a high countrate capability (approx. 1 Crab). It permits a state-of-the-art energy resolution in the energy band of 0.1 keV to 15 keV during the entire mission lifetime (e.g. FWHM ≤ 150 eV at 6 keV). This performance is accomplished by a set of DEPFET active pixel sensor matrices with a pixel size matching the angular resolution of 5 arcsec (on-axis) of the mirror system. Each DEPFET pixel is a combined detector-amplifier structure with a MOSFET integrated onto a fully depleted 450 micron thick silicon bulk. The signal electrons generated by an X-ray photon are collected in a so-called internal gate below the transistor channel. The resulting change of the conductivity of the transistor channel is proportional to the number of electrons and thus a measure for the photon energy. DEPFETs have already been developed for the "Mercury Imaging X-ray Spectrometer" on-board of ESA’s BepiColombo mission. For Athena we develop enhanced sensors with integrated electronic shutter and an additional analog storage area in each pixel. These features improve the peak-to-background ratio of the spectra and minimize dead time. The sensor will be read out with a new, fast, low-noise multi-channel analog signal processor with integrated sequencer and serial analog output. The architecture of sensor and readout ASIC allows readout in full frame mode and window mode as well by addressing selectively arbitrary sub-areas of the sensor allowing time resolution in the order of 10 μs. The further detector electronics has mainly the following tasks: digitization, pre-processing and telemetry of event data as well as supply and control of the detector system. Although the sensor will already be equipped with an on-chip light blocking filter, a filter wheel is necessary to provide an additional external filter, an on-board calibration source, an open position for outgassing, and a closed position for protection of the sensor. The sensor concept provides high quantum efficiency over the entire energy band and we intend to keep the instrumental background as low as possible by designing a graded Z-shield around the sensor. All these properties make the WFI a very powerful survey instrument, significantly surpassing currently existing observatories and in addition allow high-time resolution of the brightest X-ray sources with low pile-up and high efficiency. This manuscript will summarize the current instrument concept and design, the status of the technology development, and the envisaged baseline performance.

Since many years DEPFETs have been developed for space and ground based X-ray imaging and spectroscopy experiments. Prototypes have been successfully tested and qualified. Over the past years, the DEPFET technology was improved and additional features of DEPFETs were developed: increase of dynamic range, improvement of radiation hardness, implementation of electronic shutters, integration of an analog storage, reduction of readout noise and improvement of the low energy performance. This paper will present two novel DEPFET concepts which are able to fulfill the demanding requirements of the proposed ATHENA Wide Field Imager. It will summarize the most important DEPFET characteristics on the basis of measurements and device simulations, taking into account the given boundary conditions of the mission.

Athena is designed to implement the Hot and Energetic Universe science theme selected by the European Space Agency for the second large mission of its Cosmic Vision program. The Athena science payload consists of a large aperture high angular resolution X-ray optics (2 m2 at 1 keV) and twelve meters away, two interchangeable focal plane instruments: the X-ray Integral Field Unit (X-IFU) and the Wide Field Imager. The X-IFU is a cryogenic X-ray spectrometer, based on a large array of Transition Edge Sensors (TES), offering 2:5 eV spectral resolution, with ~5" pixels, over a field of view of 50 in diameter. In this paper, we present the X-IFU detector and readout electronics principles, some elements of the current design for the focal plane assembly and the cooling chain. We describe the current performance estimates, in terms of spectral resolution, effective area, particle background rejection and count rate capability. Finally, we emphasize on the technology developments necessary to meet the demanding requirements of the X-IFU, both for the sensor, readout electronics and cooling chain.

We are developing transition-edge sensor (TES)-based microcalorimeters for the X-ray Integral Field Unit (XIFU) of the future European X-Ray Observatory Athena. The microcalorimeters are based on TiAu TESs coupled to 250μm squared, AuBi absorbers. We designed and fabricated devices with different contact geometries between the absorber and the TES to optimise the detector performance and with different wiring topology to mitigate the self-magnetic field. The design is tailored to optimise the performance under Frequency Domain Multiplexing. In this paper we review the main design feature of the pixels array and we report on the performance of the 18 channels, 2-5MHz frequency domain multiplexer that will be used to characterised the detector array.

On 28 november 2013 ESA selected “The Hot and Energetic Universe” as the scientific theme for a large mission to be flown in 2028 in the second lagrangian point, and ATHENA is the mission that will address this science topic. It will carry on board the X-ray Integral Field Unit (X-IFU), a 3840 pixel array based on TES (Transition Edge Sensor) microcalorimeters providing high resolution spectroscopy (2.5 eV @ 6 keV) in the 0.3-12 keV range. Among X-IFU goals there is the detection and characterization of high redshift AGNs, Clusters of galaxies and their outskirts, and the elusive Warm Hot Intergalactic Medium (WHIM), so great care must be paid to the reduction of the background level. These scientific objectives will be reached if the particle background is kept lower than 0.05 cts cm⁻² s⁻¹, and to this aim, it is mandatory the use of a Cryogenic AC (CryoAC), as well as an optimized design of the cryostat and of the structures surrounding X-IFU. Our team, that is responsible for the ACD design, performed a detailed study to predict the rejection efficiency of the ACD as a function of its geometrical parameters and design choices. Since no experimental data on the background experienced by X-Ray microcalorimeters in the L2 orbit are available at the moment, the particle background levels have been calculated by means of Monte Carlo simulations using the Geant4 software.

WF-MAXI is a soft X-ray transient monitor proposed for the ISS/JEM. Unlike MAXI, it will always cover a large field of view (20 % of the entire sky) to detect short transients more efficiently. In addition to the various transient sources seen by MAXI, we hope to localize X-ray counterparts of gravitational wave events, expected to be directly detected by Advanced-LIGO, Virgo and KAGRA in late 2010's. The main instrument, the Soft X-ray Large Solid Angle Cameras (SLC) is sensitive in the 0.7-12 keV band with a localization accuracy of ~ 0:1°. The Hard X-ray Monitor (HXM) covers the same sky field in the 20 keV-1 MeV band.

DIOS (Diffuse Intergalactic Oxygen Surveyor) is a small satellite aiming for a launch around 2020 with JAXA’s Epsilon rocket. Its main aim is a search for warm-hot intergalactic medium with high-resolution X-ray spectroscopy of redshifted emission lines from OVII and OVIII ions. The superior energy resolution of TES microcalorimeters combined with a very wide field of view (30–50 arcmin diameter) will enable us to look into gas dynamics of cosmic plasmas in a wide range of spatial scales from Earth’s magnetosphere to unvirialized regions of clusters of galaxies. Mechanical and thermal design of the spacecraft and development of the TES calorimeter system are described. We also consider revising the payload design to optimize the scientific capability allowed by the boundary conditions of the small mission.

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 80keV. 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 in keeping the separation of 12m. This will survey a large sky area at hard X-ray region to study the evolution of the universe.

We are now investigating and studying a small satellite mission HiZ-GUNDAM for future observation of gamma-ray bursts (GRBs). The mission concept is to probe “the end of dark ages and the dawn of formation of astronomical objects”, i.e. the physical condition of early universe beyond the redshift z > 7. We will consider two kinds of mission payloads, (1) wide field X-ray imaging detectors for GRB discovery, and (2) a near infrared telescope with 30 cm in diameter to select the high-z GRB candidates effectively. In this paper, we explain some requirements to promote the GRB cosmology based on the past observations, and also introduce the mission concept of HiZ-GUNDAM and basic development of X-ray imaging detectors.

The Large Observatory For x-ray Timing (LOFT) was studied within ESA M3 Cosmic Vision framework and participated in the final downselection for a launch slot in 2022-2024. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument, LOFT will study the behaviour of matter under extreme conditions, such as the strong gravitational field in the innermost regions of accretion flows close to black holes and neutron stars, and the supranuclear densities in the interior of neutron stars. The science payload is based on a Large Area Detector (LAD, 10 m² effective area, 2-30 keV, 240 eV spectral resolution, 1° collimated field of view) and a Wide Field Monitor (WFM, 2-50 keV, 4 steradian field of view, 1 arcmin source location accuracy, 300 eV spectral resolution). The WFM is equipped with an on-board system for bright events (e.g. GRB) localization. The trigger time and position of these events are broadcast to the ground within 30 s from discovery. In this paper we present the status of the mission at the end of its Phase A study.

LOFT (Large Observatory For x-ray Timing) is one of the ESA M3 missions selected within the Cosmic Vision program in 2011 to carry out an assessment phase study and compete for a launch opportunity in 2022-2024. The phase-A studies of all M3 missions were completed at the end of 2013. LOFT is designed to carry on-board two instruments with sensitivity in the 2-50 keV range: a 10 m² class Large Area Detector (LAD) with a <1° collimated FoV and a wide field monitor (WFM) making use of coded masks and providing an instantaneous coverage of more than 1/3 of the sky. The prime goal of the WFM will be to detect transient sources to be observed by the LAD. However, thanks to its unique combination of a wide field of view (FoV) and energy resolution (better than 500 eV), the WFM will be also an excellent monitoring instrument to study the long term variability of many classes of X-ray sources. The WFM consists of 10 independent and identical coded mask cameras arranged in 5 pairs to provide the desired sky coverage. We provide here an overview of the instrument design, configuration, and capabilities of the LOFT WFM. The compact and modular design of the WFM could easily make the instrument concept adaptable for other missions.

LOFT (Large Observatory for X-ray Timing) is one of the five candidates that were considered by ESA as an M3 mission (with launch in 2022-2024) and has been studied during an extensive assessment phase. It is specifically designed to perform fast X-ray timing and probe the status of the matter near black holes and neutron stars. Its pointed instrument is the Large Area Detector (LAD), a 10 m²-class instrument operating in the 2-30keV range, which holds the capability to revolutionise studies of variability from X-ray sources on the millisecond time scales.

The LAD instrument has now completed the assessment phase but was not down-selected for launch. However, during the assessment, most of the trade-offs have been closed leading to a robust and well documented design that will be reproposed in future ESA calls. In this talk, we will summarize the characteristics of the LAD design and give an overview of the expectations for the instrument capabilities.

The Faint Intergalactic Redshifted Emission Balloon (FIREBall) is a NASA/CNES balloon-borne ultraviolet multi-object spectrograph designed to observe the diffuse gas around galaxies (the circumgalactic medium) via line emission redshifted to ~205 nm. FIREBall uses a ultraviolet-optimized delta doped e2v CCD201 with a custom designed high efficiency five layer anti-reflection coating. This combination achieves very high quantum efficiency (QE) and photon-counting capability, a first for a CCD detector in this wavelength range. We also present new work on red blocking mirror coatings to reduce red leak.

The HYdrogen Polarimetric Explorer (HYPE) is a sounding rocket experiment designed to obtained spectro-polarimetric measurements of diffuse ultraviolet astrophysical objects at high resolving power. HYPE consists of a spatial heterodyne spectrometer and a diamond Brewster - LiF half wave polarimeter and is optimized for study of solar scattering from interplanetary hydrogen penetrating the solar system. We report on the calibration and performance of HYPE in preparation for a first flight of the experiment.

Fireball is a NASA/CNES balloon-borne experiment to study the faint diffuse circumgalactic emission in the ultraviolet around 200 nm. The field of view of the 1 meter diameter parabola is enlarged using a two-mirror field corrector providing 1000 arcmin² at the slit mask. The 0.1 nm resolution Multi Object Spectrograph is based on two identical Schmidt systems sharing a reflective aspherical grating. The aspherization of the grating is achieved using a double replication technique of a metallic deformable matrix. We will present the F/2.5 spectrograph design and the deformable matrix process to obtain the Schmidt grating with elliptical contours.

SUAVE (Solar Ultraviolet Advanced Variability Experiment) is a far ultraviolet (FUV) imaging solar telescope of novel design for ultimate thermal stability and long lasting performances. SUAVE is a 90 mm Ritchey- Chrétien telescope with SiC (Silicon Carbide) mirrors and no entrance window for long and uncompromised observations in the UV (no coatings of mirrors, flux limited to less than a solar constant on filters to avoid degradation), associated with an ultimate thermal control (heat evacuation, focus control, stabilization). Design of the telescope and early thermal modeling leading to a representative breadboard (a R and T program supported by CNES) will be presented. SUAVE is the main instrument of the SUITS (Solar Ultraviolet Influence on Troposphere/Stratosphere) microsatellite mission, a small-size mission proposed to CNES and ESA.

The FIREBall-2 (Faint Intergalactic Redshifted Emission Balloon-2) is a balloon-borne ultraviolet spectro-imaging mission optimized for the study of faint diffuse emission around galaxies. A key optical component of the new spectrograph design is the high throughput cost-effective holographic 2400 ℓ =mm, 110x130mm aspherized reflective grating used in the range 200 - 208nm, near 28°deviation angle. In order to anticipate the efficiency in flight conditions, we have developed a PCGrate model for the FIREBall grating calibrated on linearly polarized measurements at 12° deviation angle in the range 240-350nm of a 50x50mm replica of the same master selected for the flight grating. This model predicts an efficiency within [64:7; 64:9]±0:7% (S polarization) and [38:3; 45]±2:2% (P-polarization) for the baseline aluminum coated grating with an Al₂O₃ natural oxidation layer and within [63:5; 65] ±1% (S-polarization) and [51:3; 54:8] ±2:8% (P-polarization) for an aluminum plus a 70nm MgF₂ coating, in the range 200 - 208nm and for a 28°deviation angle. The model also shows there is room for significant improvements at shorter wavelengths, of interest for future deep UV spectroscopic missions.

Four compact planetary ultraviolet spectrographs have been built by Southwest Research Institute and successfully operated on different planetary missions. These spectrographs underwent a series of ground radiometric calibrations before delivery to their respective spacecraft. In three of the four cases, the in-flight measured sensitivity was approximately 50% lower than the ground measurement. Recent tests in the Southwest Research Institute Ultraviolet Radiometric Calibration Facility (UV-RCF) explain the discrepancy between ground and flight results. Revised ground calibration results are presented for the Rosetta-Alice, New Horizons-Alice, the Lunar Reconnaissance Orbiter Lyman- Alpha Mapping Project, and Juno-Ultraviolet Spectrograph (UVS) and are then compared to the original ground and flight calibrations. The improved understanding of the calibration system reported here will result in improved ground calibration of the upcoming Jupiter Icy Moons Explorer (JUICE)-UVS.

Observations of ultraviolet light is the key to understand high temperature processes in the universe like hot plasma, accretion processes or illuminated protoplanetary discs around UV sources. Furthermore these observation contribute to major cosmological questions, like the distribution of baryonic matter or the formation of the milky way, as pointed out by Gomez de Castro et al.¹ Driven by the idea to participate in the Russian World Space Observatory we started to develop a position sensitive micro channel plate detector (MCP) for spectroscopy in the range of 160nm to 300 nm. Although we are not part of this project we still build a MCP detector prototype. In this paper we will present the general design of the detector and mainly focus on the aspect of our photocathode, while the electronics will be explained in more detail in the paper Characterisation of low power readout electronics for a UV microchannel plate detector with cross-strip readout" (Paper number 9144-116) by Marc Pfeifer.

The World Space Observatory--Ultraviolet (WSO--UV) project is a Russian-Spanish space mission for spectroscopic and imaging observations in the UV domain (115-320 nm) where some of the most important astrophysical processes can be efficiently studied with unprecedented capability. In the horizon of the next decade, WSO--UV will be the only mission with the large primary mirror fully devoted for UV studies. The observatory includes a 170 cm aperture telescope capable of high-resolution spectroscopy, long slit low-resolution spectroscopy, and deep UV imaging. The telescope T-170M is a Ritchey-Chrétien with a F/10 focal ratio and a corrected field of view of 0.5 degrees. Specific data on the WSO-UV project (telescope, satellite, orbit, launcher, ground segment, etc.) are given in [1-6]. The current status of the WSO-UV focal plane instruments, their status of implementation, and the expected performances are presented in [7]. The science drivers of the WSO-UV mission are described in [8, 9]. The main WSO-UV instruments, spectrographs (WUVS instrument) and imagers (ISSIS instrument) are described in [10-13] and [14-15] correspondingly. The prospects of stellar studies with WSO-UV are presented in papers [16-17]. A paper [18] describes our experience of using the DP-190 glue for adhesive attachment of a large space mirror and its rim. In the instrument compartment, see Figure 1, the optical bench (OB) – used as reference plane for all the onboard instrumentation – is aligned and maintained in the correct position with respect to the primary mirror (PM) using a three rods system. An imaging instrument ISSIS is mounted on the upper basis of the optical bench, in the space available between the PM and the OB itself, while spectrographs (WUVS instrument) are mounted to the OB bottom basis. One of the primary tasks in creating telescope’s PM is to apply coating with required reflective and protective properties. Aluminum is a well known reflecting coating for wavelength above 120 nm [19] with reflectivity more than 90% at wavelength longer than 200 nm, but the spectral range from 700 to 900 nm, where it’s lowest value of reflectivity is 86% at 850 nm. That makes aluminum one of the best coating materials in the creating a mirror for operations in vacuum ultraviolet. However, the aluminum membrane is prone to oxidization, so applying the protecting coating is essential. Magnesium fluoride is one of the few materials transparent in the UV range [20]. In this contribution, capacities of new facilities in LUCH company that are created for World Space Observatory – Ultraviolet (WSO-UV) project are described in Section 2, the process of applying Al + MgF₂ coating workout is presented in Section 3, results of applying Al+MgF₂ coating for WSO-UV primary mirror are presented in Section 4 and a brief summary are provided in the concluding Section 5.