This PDF file contains the front matter associated with SPIE Proceedings Volume 7011, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.

The Constellation-X Observatory is currently planned as NASA's next major X-ray observatory to be launched towards the end of the next decade. The driving science goals for the mission are to: 1) Trace the evolution of Black Holes with cosmic time and determine their contribution to the energy output of the Universe; 2) Observe matter spiraling into Black Holes to test the predictions of General Relativity; 3) Use galaxy clusters to trace the locations of Dark Matter and follow the formation of structure as a function of distance; 4) Search for the missing baryonic matter; 5) Directly observe the dynamics of Cosmic Feedback to test models for galaxy formation; 6) Observe the creation and dispersion of the elements in supernovae; and 7) Precisely constrain the equation of state of neutron stars. To achieve these science goals requires high resolution (R > 1250) X-ray spectroscopy with 100 times the throughput of the Chandra and XMMNewton. The Constellation-X Observatory will achieve this requirement with a combination of four large X-ray telescopes on a single satellite operating in the 0.25 to 10 keV range. These telescopes will feed X-ray micro-calorimeter arrays and grating spectrometers. A hard X-ray telescope system will provide coverage up to at least 40 keV. We describe the mission science drivers and the mission implementation approach.

As NASA's next major space X-ray observatory, the Constellation-X mission (Bookbinder et al. 2008) requires mirror assemblies with unprecedented characteristics that cannot be provided by existing optical technologies. In the past several years, the project has supported a vigorous mirror technology development program. This program includes the fabrication of lightweight mirror segments by slumping commercially available thin glass sheets, the support and mounting of these thin mirror segments for accurate metrology, the mounting and attachment of these mirror segments for the purpose of X-ray tests, and development of methods for aligning and integrating these mirror segments into mirror assemblies. This paper describes our efforts and developments in these areas.

Following our development of a superconducting transition-edge-sensor (TES) microcalorimeter design that en- ables reproducible, high performance (routinely better than 3 eV FWHM energy resolution at 6 keV) and is compatible with high-fill-factor arrays, we have directed our efforts towards demonstrating arrays of identical pixels using the multiplexed read-out concept needed for instrumenting the Constellation-X X-ray Microcalorime- ter Spectrometer (XMS) focal plane array. We have used a state-of-the-art, time-division SQUID multiplexer system to demonstrate 2 ×8 multiplexing (16 pixels read out with two signal channels) with an acceptably modest level of degradation in the energy resolution. The average resolution for the 16 multiplexed pixels was 2.9 eV, and the distribution of resolution values had a relative standard deviation of 5%. The performance of the array while multiplexed is well understood. The technical path to realizing multiplexing for the XMS instrument on the scale of 32 pixels per signal channel includes increasing the system bandwidth by a factor of four and reducing the non-multiplexed SQUID noise by a factor of two. In this paper we discuss the characteristics of a uniform 8 ×8 array and its performance when read out non- multiplexed and with various degrees of multiplexing. We present data acquired through the readout chain from the multiplexer electronics, through the real-time demultiplexer software, to storage for later signal processing. We also report on a demonstration of real-time data processing. Finally, because the multiplexer provides unprecedented simultaneous access to the pixels of the array, we were able to measure the array-scale uniformity of TES calorimeter parameters such as the individual thermal conductances and superconducting transition temperatures of the pixels. Detector uniformity is essential for optimal operation of a multiplexed array, and we found that the distributions of thermal conductances, transition temperatures, and transition slopes were sufficiently tight to avoid significant compromises in the operation of any pixel.

We have developed a new type of soft x-ray diffraction grating. This critical-angle transmission (CAT) grating combines the advantages of traditional transmission gratings (low mass, extremely relaxed alignment and flatness tolerances) with those of x-ray reflection gratings (high efficiency due to blazing in the direction of grazing-incidence reflection, increased resolution due to the use of higher diffraction orders). In addition, grating spectrometers based on CAT gratings are well-suited for co-existence with high-energy focal plane microcalorimeter detectors as planned for the Constellation-X mission, since most high-energy x rays are neither absorbed nor deflected, and arrive at the telescope focus. We describe the CAT grating principle and design, and fabrication and x-ray diffraction efficiency results for a CAT grating with 1742 lines/mm. We have observed up to 46% diffraction efficiency in a single order, and up to 55% at blaze at extreme ultraviolet wavelengths. We present our recent fabrication and soft x-ray diffraction results for 200 nm-period (5000 lines/mm) gratings.

We present the latest design of an off-plane reflection grating array for the Constellation-X X-ray Grating Spectrometer. The off-plane design can easily demonstrate the baseline requirements of resolution, R > 1250 and throughput, effective area > 1000 cm² from 0.3 - 1.0 keV. Furthermore, the flexibility of the design allows for several avenues for optimization of these factors. We consider two configurations, 3 m and 9 m from the focal plane using a 20 m focal length telescope. The trade-offs between the two options are discussed.

The future large X-ray astrophysics observatories after XMM and Chandra will require novel optics to be developed, in order to provide the combination of large effective area, low mass and adequate angular resolution. In particular the XEUS mission candidate [1,2], as selected in the first slice of the Cosmic Vision 1525 programme, has stringent and demanding requirements on the performance of the required X-ray optics forming the core of the mission concept. A summary of the specific requirements and boundary conditions for the XEUS X-ray optics is provided, followed by an outline and status of the options being considered in the XEUS studies and technology preparations. A discussion of the main design parameters is done, in particular of the impact of the focal length choice, and the application of coatings. The feasibility of the mechanical implementation of the considered telescope optical design in a flight model is not addressed in this study.

This paper describes the focal plane instrumentation of the XEUS mission as proposed for ESA's Cosmic Vision program. Each of the instruments is described in some detail with its performance characteristics given. The development status of the instrument complement and the items requiring further development are indicated.

One of the major sciences of XEUS is the evolution of massive black holes from early to current Universe. As is well known, considerable fraction of massive black holes harbored in active galactic nuclei are embedded in thick absorbing material. In order to observe black holes without any bias of absorption, we propose a hard X-ray imaging system to XEUS. The hard X-ray imaging system is consisted of super mirror X-ray telescopes with multilayer coating and of the position sensitive hard X-ray imaging CdTe detector. Under the current boundary conditions, the design parameters will be optimized for the telescope and the multilayers. Current achievements of hard X-ray imaging detectors are also presented.

XEUS has been recently selected by ESA for an assessment study. XEUS is a large mission candidate for the Cosmic Vision program, aiming for a launch date as early as 2018. XEUS is a follow-on to ESA's Cornerstone X-Ray Spectroscopy Mission (XMM-Newton). It will be placed in a halo orbit at L2, by a single Ariane 5 ECA, and comprises two spacecrafts. The Silicon pore optics assembly of XEUS is contained in the mirror spacecraft while the focal plane instruments are contained in the detector spacecraft, which is maintained at the focus of the mirror by formation flying. The main requirements for XEUS are to provide a focused beam of X-rays with an effective aperture of 5 m² at 1 keV, 2 m² at 7 keV, a spatial resolution better than 5 arcsec, a spectral resolution ranging from 2 to 6 eV in the 0.1-8 keV energy band, a total energy bandpass of 0.1-40 keV, ultra-fast timing, and finally polarimetric capabilities. The High Time Resolution Spectrometer (HTRS) is one of the five focal plane instruments, which comprises also a wide field imager, a hard X-ray imager, a cryogenic spectrometer, and a polarimeter. The HTRS is unique in its ability to cope with extremely high count rates (up to 2 Mcts/s), while providing sub-millisecond time resolution and good (CCD like) energy resolution. In this paper, we focus on the specific scientific objectives to be pursued with the HTRS: they are all centered around the key theme "Matter under extreme conditions" of the Cosmic Vision science program. We demonstrate the potential of the HTRS observations to probe strong gravity and matter at supra-nuclear densities. We conclude this paper by describing the current implementation of the HTRS in the XEUS focal plane.

The XEUS mission incorporates two satellites: the Mirror Spacecraft with 5 m² of collecting area at 1 keV and 2 m² at 7 keV, and an imaging resolution of 5" HEW and the Payload Spacecraft which carries the focal plane instrumentation. XEUS was submitted to ESA Cosmic Vision and was selected for an advanced study as a large mission. The baseline design includes XPOL, a polarimeter based on the photoelectric effect, that takes advantage of the large effective area which permits the study of the faint sources and of the long focal length, resulting in a very good spatial resolution, which allows the study of spatial features in extended sources. We show how, with XEUS, Polarimetry becomes an efficient tool at disposition of the Astronomical community.

The XEUS (X-ray Evolving Universe Spectroscopy) proposal has been recently selected by the science advisory structure of the European Space Agency as an L-class candidate mission. On this basis, XEUS will undergo an assessment study, in line with the Cosmic Vision 2015-2025 selection process. The mission would represent a follow-up to XMM-Newton, providing a next generation X-ray observatory at disposal of the astrophysics community. The paper provides an overview of the recent study activities performed by ESA, including a critical review of the main requirements and a discussion on the associated impact at system level. The model payload presently considered for XEUS is also presented, as well as the technology developments needs.

The Spectrum-RG (SRG) mission, to be launched in 2011, will conduct the first all-sky survey in the 0.1-15 keV band via two imaging telescope systems, eROSITA and ART-XC. These will enable the detection of about 100 thousand clusters of galaxies and the mapping of the large scale structure of the Universe. They will also discover all obscured accreting Black Holes in nearby galaxies and about ≥3 million new, distant AGNs. In the course of the survey mode two sky regions around the celestial polar zones will be observed with much higher sensitivity. Then, selected sources and dedicated sky regions will be observed in a pointing mode with high sensitivity in order to investigate the nature of dark matter and dark energy. An X-Ray Calorimeter, the SXC experiment, will permit observations of the brightest clusters of galaxies with record energy resolution in pointing mode and mapping of the hot intergalactic medium in the survey mode.

The German X-ray observatory eROSITA (extended ROentgen Survey with an Imaging Telescope Array) is the prime instrument of the new Spectrum-RG mission. Launch of the Russian satellite is planned for the year 2011. The scientific goal of eROSITA is primarily the detection and analysis of 100 thousand clusters of galaxies in order to study the large scale structures in the Universe and to test cosmological models. The therefore required large effective area is obtained by an array of seven identical and parallel aligned Wolter-I telescopes. In the focus of each mirror module, there is a large frame store pnCCD detector, providing a field of view of 1° in diameter. The same X-ray detector type will also be applied for ART-XC, another grazing-incidence telescope system aboard Spectrum-RG, which permits the detection of heavily obscured X-ray sources. These scientific instruments allow the exploration of the X-ray Universe in the energy band from 0.3 keV to 11 keV. During a mission time of at least five years, an all-sky survey, wide as well as deep surveys and pointed observations will be performed. Approval and funding for eROSITA were granted by the German space agency DLR in April 2007. The conceptual design of the X-ray focal plane cameras is presented here comprising electrical, thermal, and mechanical aspects. Key part of the camera is the pnCCD detector chip, which is developed and produced in our semiconductor laboratory, the MPI Halbleiterlabor. The CCD was designed according to the specifications given by the scientific goals of eROSITA. The eROSITA CCD differs apparently from all previously produced frame store pnCCDs by its larger size and format. The CCD image area of the seven eROSITA cameras is in total 58 cm² large and their number of pixels is about seven times higher than that of the XMM-Newton pnCCD camera. First pnCCD devices were recently produced and tested. Their performance measurements and results are of most importance for eROSITA because the tested CCDs are the control sample of the flight detector production.

Spatially resolved X-ray spectroscopy with high spectral resolution allows the study of astrophysical processes in extended sources with unprecedented sensitivity. This includes the measurement of abundances, temperatures, densities, ionisation stages as well as turbulence and velocity structures in these sources. An X-ray calorimeter is planned for the Russian mission Spektr Röntgen-Gamma (SRG), to be launched in 2011. During the first half year (pointed phase) it will study the dynamics and composition of of the hot gas in massive clusters of galaxies and in supernova remnants (SNR). During the survey phase it will produce the first all sky maps of line-rich spectra of the interstellar medium (ISM). Spectral analysis will be feasible for typically every 5° x 5° region on the sky. Considering the very short time-scale for the development of this instrument it consists of a combination of well developed systems. For the optics an extra eROSITA mirror, also part of the Spektr-RG payload, will be used. The detector will be based on spare parts of the detector flown on Suzaku combined with a rebuild of the electronics and the cooler will be based on the design for the Japanese mission NeXT. In this paper we will present the science and give an overview of the instrument.

The ART-XC instrument is an X-ray grazing-incidence telescope system in an ABRIXAS-type optical configuration optimized for the survey observational mode of the Spectrum-RG astrophysical mission which is scheduled to be launched in 2011. ART-XC has two units, each equipped with four identical X-ray multi-shell mirror modules. The optical axes of the individual mirror modules are not parallel but are separated by several degrees to permit the four modules to share a single CCD focal plane detector, 1/4 of the area each. The 450-micron-thick pnCCD (similar to the adjacent eROSITA telescope detector) will allow the detection of X-ray photons up to 15 keV. The field of view of the individual mirror module is about 18×18 arcminutes² and the sensitivity of the ART-XC system for 4 years of survey will be better than 10^-12 erg s^-1 cm^-2 over the 4-12 keV energy band. This will allow the ART-XC instrument to discover several thousands new AGNs.

The SIMBOL-X formation-flight X-ray mission will be operated by ASI and CNES in 2014, with a large participation of the French and Italian high energy astrophysics scientific community. Also German and US Institutions are contributing in the implementation of the scientific payload. Thanks to the formation-flight architecture, it will be possible to operate a long (20 m) focal length grazing incidence mirror module, formed by 100 confocal multilayer-coated Wolter I shells. This system will allow us to focus X-rays over a very broad energy band, from 0.5 keV up to 80 keV and beyond, with more than two orders of magnitude improvement in angular resolution (20 arcsec HEW) and sensitivity (0.5 µCrab on axis @30 keV) compared to non focusing detectors used so far. The X-ray mirrors will be realized by Ni electroforming replication, already successfully used for BeppoSAX, XMM-Newton, and JET-X/SWIFT; the thickness trend will be about two times less than for XMM, in order to save mass. Multilayer reflecting coatings will be implemented, in order to improve the reflectivity beyond 10 keV and to increase the field of view 812 arcmin at 30 keV). In this paper, the SIMBOL-X optics design, technology and implementation challenges will be discussed; it will be also reported on recent results obtained in the context of the SIMBOL-X optics development activities.

The NeXT (New exploration X-ray Telescope), the new Japanese X-ray Astronomy Satellite following Suzaku, is an international X-ray mission which is currently planed for launch in 2013. NeXT is a combination of wide band X-ray spectroscopy (3-80 keV) provided by multi-layer coating, focusing hard X-ray mirrors and hard X-ray imaging detectors, and high energy-resolution soft X-ray spectroscopy (0.3-10 keV) provided by thin-foil X-ray optics and a micro-calorimeter array. The mission will also carry an X-ray CCD camera as a focal plane detector for a soft X-ray telescope and a non-focusing soft gamma-ray detector. With these instruments, NeXT covers very wide energy range from 0.3 keV to 600 keV. The micro-calorimeter system will be developed by international collaboration lead by ISAS/JAXA and NASA. The simultaneous broad bandpass, coupled with high spectral resolution of ΔE ~7 eV by the micro-calorimeter will enable a wide variety of important science themes to be pursued.

Japan's NeXT mission has been approved for the Phase-A in 2007. At present NeXT is in the process of transition to the Phase-B. One of the unique feature of the mission is an imaging spectroscopy in unprecedentedly wide energy region from 0.5 to 80 keV. The X-Ray Telescope (XRT) system covers the energy region by means of grazing incidence reflective optics. International collaboration has been formed for the project and design and basic study have been carried out so far. Current baseline specification includes two hard X-ray telescopes which are combined with the Hard X-ray Imager (Si + CdTe pixel or strip) and cover 5 to 80 keV, and two soft X-ray telescopes which cover 0.3 to about 20 keV, one combined with a high resolution X-ray micro-calorimeter and the other with an X-ray CCD. Both of hard and soft X-ray mirrors employ same optical design; tightly-nested, conically-approximated thin-foil Wolter-I optics. The mission requirements for XRT system have been identified as 300 cm² at 30 keV for the hard X-ray telescope in total and 400 cm² at 6 keV for the soft X-ray telescope per unit. The requirement on the point spread function is 1.7 arcmin in HPD, as well as the goal being 1.2 arcmin. Based on the current level of technology all the mission requirements are expected to be satisfied.

The Soft X-ray Imager (SXI) is the X-ray CCD camera on board the NeXT mission that is to be launched around 2013. We are going to employ the CCD chips developed at Hamamatsu Photonics, K.K. We have been developing two types of the CCD: an N-channel chip and a P-channel chip. The effective area of the detector system will be 5-6 cm square with a depletion layer of 100-200μm. The P-channel chip will have thicker depletion layer that makes it easy to develop it to back-illuminated type CCD. It will need a year or so for us to reach the final conclusion which type will be available. Based on the Suzaku experience, we will incorporate the charge injection gate so that we can reduce the proton damage. Furthermore, we will employ a mechanical cooler to keep the CCD working temperature down to -120°C in spite that NeXT will be in the low earth orbit. We can expect the radiation damage on our system very small. The CCD will have an Al coat on the chip to prevent optical photons from entering. This also eliminates the vacuum-tight chamber and the door-opening mechanism. We are planning to employ a custom-made analog ASIC that will reduce the power consumption and the size. The ASIC may speed up the frame-time if we can use a multi-node CCD. With using the focal length of 6m, the SXI will fully function with the optics around 20" resolution. We will report the current plan of the SXI in detail.

The Hard X-ray Imager (HXI) is one of three focal plane detectors on board the NeXT (New exploration X-ray Telescope) mission, which is scheduled to be launched in 2013. By use of the hybrid structure composed of double-sided silicon strip detectors and a cadmium telluride strip detector, it fully covers the energy range of photons collected with the hard X-ray telescope up to 80 keV with a high quantum efficiency. High spatial resolutions of 400 micron pitch and energy resolutions of 1-2 keV (FWMH) are at the same time achieved with low noise front-end ASICs. In addition, thick BGO active shields compactly surrounding the main detection part, as a heritage of the successful performance of the Hard X-ray Detector (HXD) on board Suzaku satellite, enable to achive an extremely high background reduction for the cosmic-ray particle background and in-orbit activation. The current status of hardware development including the design requirement, expected performance, and technical readinesses of key technologies are summarized.

MASSIM, the Milli-Arc-Second Structure Imager, is a mission that has been proposed for study within the context of NASA's Astrophysics Strategic Mission Concept Studies program. It uses a set of achromatic diffractive-refractive Fresnel lenses on an optics spacecraft to focus 5-11 keV X-rays onto detectors on a second spacecraft flying in formation 1000 km away. It will have a point-source sensitivity comparable with that of the current generation of major X-ray observatories (Chandra, XMM-Newton) but an angular resolution some three orders of magnitude better. MASSIM is optimized for the study of jets and other phenomena that occur in the immediate vicinity of black holes and neutron stars. It can also be used for studying other astrophysical phenomena on the milli-arc-second scale, such as those involving proto-stars, the surfaces and surroundings of nearby active stars and interacting winds. We describe the MASSIM mission concept, scientific objectives and the trade-offs within the X-ray optics design. The anticipated performance of the mission and possible future developments using the diffractive-refractive optics approach to imaging at X-ray and gamma-ray energies are discussed.

The angular resolution of Chandra is close to the practical limit of grazing incidence telescopes due to the difficulty of imparting an accurate figure and smooth surface to mirror substrates whose physical area is over two orders of magnitude larger than their effective area. However, important scientific objectives lie beyond the reach of Chandra and all future missions being planned by the space agencies. By transmitting X-rays diffractive and refractive optics are not subject to the same limitations and have a superior diffraction limit. A Fresnel zone plate can be paired with a refractive lens such that their intrinsic chromatic aberrations cancel to 1st order at a specific energy. The result is a limited but significant energy band where the resolution is a milli arc second or better, for example, at 6 keV. Chromatic aberration can be corrected to 2nd order by separating the diffractive and refractive elements. This configuration allows a resolution of a few micro arc seconds. The optics are very light weight but have extremely long focal lengths resulting in a requirement for very long distance formation flying between optics and detector spacecraft, and small fields of view. Opacity of the refractive element imposes a lower limit upon the X-ray energy of about a few keV.

For X-ray astronomy, 0.1 arc-second imaging resolution will result in a significant advance in our understanding of the Universe. Similarly, the advent of low cost high performance X-ray mirrors will also increase the likelihood of more X-ray telescopes being funded and built. We discuss the development plans of two different types of adjustable grazing incidence optics: one being a tenth arc-second resolution bimorph mirror approach also suitable for extremely large collecting areas, and the second being a few arc-second radially adjustable mirror approach more suitable for modest sized telescopes. Bimorph mirrors will be developed using thin (0.1 - 0.4 mm) thermally formed glass or electroplated metal mirror segments with thin film piezo-electric actuators deposited directly on the mirror back surface. Mirror figure will be adjusted on-orbit. Radially adjustable mirrors will employ discreet radially electrostrictive actuators for mirror alignment and low spatial error frequency figure correction during assembly and alignment. In this paper we report on. In this paper we describe mirror design and our development plans for both mirror concepts.

Generation-X will be an X-ray observatory with 50 m² collecting area at 1 keV and 0.1" angular resolution. A key concept to enable such a dramatic improvement in angular resolution is that the mirror figure will be adjusted on-orbit; e.g., via piezo-electric actuators deposited on the back side of very thin glass and imparting strains in a bi-morph configuration. To make local adjustments to the individual mirror shells we must employ an imaging detector far forward of the focal surface, so that rays from the individual shells can be measured as distinct rings. We simulate this process on a few representative shells via ray-traces of perfect optics, perturbed axially by low order Legendre polynomial terms. This elucidates some of the requirements for the on-orbit measurements, and on possible algorithms to perform the on-orbit adjustment with acceptably rapid convergence.

The Smart X-ray Optics (SXO) project is a UK based consortium consisting of several institutions investigating the application of active/adaptive optics to both large and small scale grazing incidence x-ray optics. University College London presents work relating to the large scale x-ray optics that is geared towards the next generation of x-ray space telescopes. It is proposed that through the addition of piezoelectric actuators, an active x-ray telescope with a resolution better than that currently achieved (e.g. Chandra 0.5") could be realised. An immediate aim of the SXO project is to produce an operational active ellipsoidal segment prototype, with point-to- point focusing and with the intention of being tested at the University of Leicester's x-ray beam source. Work relating to the fabrication of the prototype will be presented, including shell replication via a nickel sulphamate electroforming process, piezoelectric actuators and prototype assembly and operation. Results from finite element analysis modelling will be discussed; these relate primarily to gravitational distortion effects and the plating tank electrostatics.

The Smart X-ray Optics project is a UK based consortium of eight institutions investigating the application of active/adaptive X-ray optics for both large and small scale. The work being undertaken at the University of Leicester includes the modelling and testing of a large scale optic, suitable for an X-ray telescope. This will incorporate piezoelectric devices to enable the surface to be actively deformed, aiming to achieve an angular resolution better than that currently available (e.g. Chandra 0.5"). The test optic design is based on a thin Nickel ellipsoid segment on the back of which will be bonded a series of piezoelectric actuators. Simulation of the X-ray performance and the effect of the actuated piezoelectric devices on the detected image is described. Details of the models produced for the piezoelectric actuation routine and the simulated annealing algorithm under development, will be outlined. Planed testing of the ellipsoidal prototype and future objectives for implementation of active X-ray optics in the design of an X-ray telescope will be discussed.

A high-precision ultra-lightweight 0.5m mirror with ultraviolet grade tolerances on surface figure quality has been measured from its delivery to the Goddard Space Flight Center, through the coating and mounting process, and shown to survive component vibration testing. This 4.5kg, 0.5m paraboloid mirror is the prime optic of two sounding-rocket telescopes: SHARPI (solar high angular resolution photometric imager) and PICTURE (planet imaging concept testbed using a rocket experiment). By integrating the analysis of interferometer data with finite element models, we demonstrate the ability to isolate surface figure effects comparable to UV diffraction limited tolerances from much larger gravity and mount distortions. The ability to measure such features paired with in situ monitoring of mirror figure through the mirror mounting process has allowed for a diagnosis of perturbations and the remediation of process errors. In this paper, we describe the technical approach used to achieve nanometer scale measurement accuracy, we report and decompose the final mounted surface figure of 12.5 nm RMS, and we describe the techniques that were developed and employed in the pursuit of maintaining UV diffraction-limited performance with this aggressively lightweighted mirror.

For more than 40 years in Marseille Provence observatories active optics concepts have found many fruitful developments in uv, visible and ir telescope optics. For these wavelength ranges, active optics methods are now widely extended by current use of variable curvature mirrors, in situ aspherization processes, stress figuring apsherization processes, replications of stressed diffraction gratings, and in situ control of large telescope optics. X-ray telescope mirrors will also benefit soon from the enhanced performances of active optics. For instance, the 0.5-1 arcsec spatial resolution of Chandra will be followed up by increased resolution space telescopes which will require the effective construction of more strictly aplanatic grazing-incidence two-mirror systems. In view to achieve a high-resolution imaging with two-mirror grazing-incidence telescope, say, 0.1 arcsec, this article briefly reviews the alternative optical concepts. Next, active optics analysis is investigated with the elasticity theory of shells for the active aspherization and in situ control of monolithic and segmented telescope mirrors for x-ray astronomy. An elasticity theory of weakly conical shells is developed for a first approach which uses a monotonic extension (or retraction) of the shell.

Each of the four Spectroscopy X-ray Telescopes (SXT) on Constellation-X contain a mirror assembly comprised of 2600 primary and secondary mirror segments. Critical to the performance of the mirror assemblies is the alignment of secondary to primary, and alignment of mirror pairs to one another. Focus errors must be corrected in order to meet imaging error budgets. The use of segmented mirrors enables unique alignment strategies not feasible with mirror shells of a full revolution. We discuss the relative advantages and disadvantages of two Con-X alignment strategies to minimize focus errors between shells. In the first approach, the mirrors are bent azimuthally to adjust the focal length of the mirror pair. In the second approach, coma is used to compensate for the transverse focus error. We examine the limits of applicability of the two approaches, and also discuss alignment error budgets.

The four Constellation-X Spectroscopy X-ray Telescopes require four sets of 2,600 thin mirror segments be supported with minimum deformation and aligned with arc-second level accuracy. We have developed a support and alignment system that minimizes segment deformation and allows the mirror segments to be made confocal. This system relies upon a set of five mirror support points at each of the forward and aft ends of each segment. The support points are radially adjustable so as to be able to modify the segment cone angles, thereby correcting any focal length errors. Additional adjustments enable correction of segment centration and tilts to correct co-alignment errors and minimize comatic aberration. The support and alignment system is described and results are presented. Included are data demonstrating minimal levels of figure distortion. Results are compared with error budget allocations.

The next large x-ray astrophysics mission launched will likely include soft x-ray spectroscopy as a primary capability. A requirement to fulfill the science goals of such a mission is a large-area x-ray telescope focusing sufficient x-ray flux to perform high-resolution spectroscopy with reasonable observing times. One approach to manufacturing such a telescope is a Wolter-I optic utilizing thin glass segments rather than full shells of revolution. We describe a parameterized Finite Element Modeling (FEM) study that provides insights useful in optimizing the design of a discrete support system to balance the competing requirements of minimizing the effect on optical performance while providing sufficient support to withstand launch loads. Parameters analyzed are number and location of the supports around the glass segments, as well as the glass thickness, size, and angular span. In addition, we utilize more detailed models of several cases taken from the parametric study to examine stress around the bonded area and bond pad size, and compare the stress from the detailed model to the parametric cases from which they were derived.

The Constellation-X Spectroscopy X-Ray Telescopes consists of segmented glass mirrors with an axial length of 200 mm, a width of up to 400 mm, and a thickness of 0.4 mm. To meet the requirement of < 15 arc-second half-power diameter with the small thickness and relatively large size is a tremendous challenge in opto-mechanics. How shall we limit distortion of the mirrors due to gravity in ground tests, that arises from thermal stress, and that occurs in the process of mounting, affixing and assembling of these mirrors? In this paper, we will describe our current opto-mechanical approach to these problems. We will discuss, in particular, the approach and experiment where the mirrors are mounted vertically by first suspending it at two points.

Wolter type I X-ray telescopes made of slumped glass could be a light-weight alternative to nickel replica optics. We are following the goal to develop the slumping methods for high accuracy glass segments with an angular resolution of a few arcseconds by experimental means. The development of segmented glass optics falls into three distinct areas: slumping process, metrology and optics assembly. We report on our results in studying the sequence of the slumping process. By observing the effects of different parameters we got a fine grasp on the process itself. The design of different metrology methods to measure the figure of the glass segments both in visual and X-ray wavelengths were under way. Integrating the segments into a structure became a main part in our development. We report on first results.

We report on recent progress with development of astronomical X-ray optics based on thermally formed glass foils and on bent Si wafers. Experiments with thermal glass forming have continued adding wider range of evaluated and optimized parameters. Recent efforts with Si wafers have been focused on their quality improvements such as flatness and thickness uniformity in order to better meet the requirements of future X-ray astronomy projects applications, as well as on study of their surface quality, defects analysis, and methods for its reproducible measurement. The role of substrates quality in performance of final mirror arrays, as required by large future space X-ray astronomy experiments was also studied. The problem of increasing size of Si wafers, required for some X-ray optics applications, is also addressed. First results of irradiation tests of selected substrates are also reported and discussed.

The PANTER X-ray Test Facility has been utilized successfully for developing and calibrating X-ray astronomical instrumentation for observatories such as ROSAT, Chandra, XMM-Newton, Swift, etc. Future missions like eROSITA, SIMBOL-X, or XEUS require improved spatial resolution and broader energy band pass, both for optics and for cameras. Calibration campaigns at PANTER have made use of flight spare instrumentation for space applications; here we report on a new dedicated CCD camera for on-ground calibration, called TRoPIC. As the CCD is similar to ones used for eROSITA (pn-type, back-illuminated, 75 μm pixel size, frame store mode, 450 μm micron wafer thickness, etc.) it can serve as prototype for eROSITA camera development. New techniques enable and enhance the analysis of measurements of eROSITA shells or silicon pore optics. Specifically, we show how sub-pixel resolution can be utilized to improve spatial resolution and subsequently the characterization of of mirror shell quality and of point spread function parameters in particular, also relevant for position reconstruction of astronomical sources in orbit.

A number of future X-ray astronomy missions (e.g. Simbol-X, eROSITA) plan to utilize high throughput grazing incidence optics with very lightweight mirrors. The severe mass specifications require a further optimization of the existing technology with the consequent need of proper optical numerical modeling capabilities for both the masters and the mirrors. A ray tracing code has been developed for the simulation of the optical performance of type I Wolter masters and mirrors starting from 2D and 3D metrology data. In particular, in the case of 2D measurements, a 3D data set is reconstructed on the basis of dimensional references and used for the optical analysis by ray tracing. In this approach, the actual 3D shape is used for the optical analysis, thus avoiding the need of combining the separate contributions of different 2D measurements that require the knowledge of their interactions which is not normally available. The paper describes the proposed approach and presents examples of application on a prototype engineering master in the frame of ongoing activities carried out for present and future X-ray missions.

X-ray Wolter focusing telescopes concentrate the light by means of reflection on smooth surfaces at small grazing angle (below a couple of degrees). The traditional coatings for these kind of applications are heavy materials that, due to their high density, present a high critical energy for total reflection. Recent works have shown how a thin layer of a light material, like carbon, on top of a traditional reflecting coating, can enhance the reflectivity in soft x-ray spectral region (below 5 keV), without degrading the performances for higher energies. We presented at SPIE 2007 some experimental results about the reflectivity measurement at very low energies (200 eV) and rather large angles (1-2 deg). In the present work we extend the former study, by the realization of a new set of samples with coatings made of different materials (Pt, Au, W, Ir) and the measurement of their reflectivity for the typical angles (< 1°) and energies (1-10 keV) employed in astronomical grazing incidence telescopes.

It is proposed that the primary mirror for the X-ray observatory XEUS has an angular resolution of ~2 arc seconds, and is constructed using a new type of pore optics manufactured from Silicon. The point spread function of such optics results from the summed effect of millions of pores and is limited by a combination of geometrical optics, diffraction and scattering. In the case of XEUS, all three effects are of importance, as diffraction dominates at lower energies. Reaching this ambitious resolution goal is a major challenge of the mission. We present analytical and numerical calculations which provide a prediction of the point spread function including inherent geometric and diffraction effects associated with the pore geometry, manufacturing/figuring errors, misalignments and surface roughness. The rough reflecting surface of one pore is modelled as a number of planar patches. The wave fronts reflected from these patches are propagated to the detector plane, taking into account geometrical and diffraction effects over the whole energy range. Summation of these wave fronts gives us a general analytical point spread function for a pore. In a computationally intensive step numerical values are then applied and the point spread function calculated. First results are shown for one pore and in one dimension (radially).

The XEUS mission is conceived as Europe's next generation X-ray space observatory aiming at the detection and spectroscopy of faint astronomical sources located at high red-shift. With unprecedented sensitivity to the million-degree hot universe, XEUS is supposed to explore key areas of contemporary astrophysics. Due to the considerable telescope focal length of 35 m, the mission profile foresees two separate spacecraft, one carrying the mirrors, the other one carrying the detectors, flying in precise formation as if connected by a rigid telescope tube. The paper presents an innovative light-weight X-ray telescope design and its predicted performance as resulting from a recent study on XEUS Telescope Accommodation funded by the European Space Agency ESA. The main challenge of this work was to find a telescope concept compatible with the Ariane V launcher constraints while meeting highly demanding optical performance requirements.

We describe a set of measurements on coated silicon substrates that are representative of the material to be used for the XEUS High Performance Pore Optics (HPO) technology. X-ray angular reflectance measurements at 2.8 and 8 keV, and energy scans of reflectance at a fixed angle representative of XEUS graze angles are presented. Reflectance is significantly enhanced for low energies when a low atomic number over-coating is applied. Modeling of the layer thicknesses and roughness is used to investigate the dependence on the layer thicknesses, metal and over coat material choices. We compare the low energy effective area increase that could be achieved with an optimized coating design.

Silicon pore optics have been developed over the last years to enable future astrophysical X-ray telescopes and have now become a candidate mirror technology for the XEUS mission. Scientific requirements demand an angular resolution better than 5" and a large effective area of several square meters at photon energies of 1 keV. This paper discusses the performance of the latest generation of these novel light, stiff and modular X-ray optics, based on ribbed plates made from commercial high grade 12" silicon wafers. Stacks with several tens of silicon plates have been assembled in the course of an ESA technology development program, by bending the plates into accurate shape and directly bonding them on top of each other. Several mirror modules, using two stacks each, have been aligned and integrated to form the conical approximation of a Wolter-I design. This paper presents the status of the technology, addresses and discusses a number of activities in the ongoing ESA technology development and shows latest results of full area measurements at the MPE X-ray test facility (PANTER).

The XEUS mission (X-ray Evolving-Universe Spectroscopy Mission) of ESA, in the present configuration has a mirror collecting area in the order of 5-6 m² @ 1 keV, 2 m² @ 7 keV and 1 m² @ 10 keV. These large collecting areas could be obtained with a mirror assembly composed of a large number of high quality segments each being able to deliver the angular resolution requested by the mission or better. The XEUS telescope will fit in the fairing of an Ariane 5 ECA launcher and hence its diameter is presently of about 4.5 m. The request in terms of angular resolution of the telescope has been set to 5 arcsec with a goal of 2 arcsec. Due to the large size of the optics it is impossible to create closed shells like those used for XMM or Chandra and hence it will be necessary to assemble a large number of segments (for example of ~0.6 m x ~0.3 m size) to recreate the mirror shells. These segments will form a module, an optical sub-unit of the telescope. The modules will be assembled to form the whole mirror system. As for all the space missions, the limits imposed on the payload mass budget by the launcher is the main driver that force the use of very lightweight optics and this request is of course very challenging. For example, the current design for XEUS foresees a geometric-area/mass ratio better than about 30 cm²/kg. In this article is illustrated a possible approach for the realization of large size and lightweight X-ray mirrors that derive from an experience gained from a previous work made in INAF-OAB on the thermal slumping of thin glass optics. The process foresees the use of a mould having a good optical figure but opposite shape respect to the segment to be slumped. On the mould is placed an initially flat glass sheet. With a suitable thermal cycle the glass sheet is conformed to the mould shape. Once tested for acceptance the glass sheet it is then integrated into a module by means of a robotic arm having a feedback system to confirm the correct alignment. A study on different optical geometries using the classical Wolter I and Kirkpatrick-Baez configurations has been also performed to investigate the theoretical performances obtainable with optics made using very thin glass shells.

We present the current status of a small X-ray mission DIOS (Diffuse Intergalactic Oxygen Surveyor), consisting of a 4-stage X-ray telescope and an array of TES microcalorimeters, cooled with mechanical coolers, with a total weight of about 400 kg. The mission will perform survey observations of warm-hot intergalactic medium using OVII and OVIII emission lines, with the energy coverage up to 1.5 keV. The wide field of view of about 50' diameter, superior energy resolution close to 2 eV FWHM, and very low background will together enable us a wide range of science for diffuse X-ray sources. We briefly describe the current status of the development of the satellite, and the subsystems.

Technical progress in X-ray optics and in polarization-sensitive X-ray detectors, which our groups pioneered, enables a scientifically powerful, dedicated space mission for imaging X-ray polarimetry. This mission is sufficiently sensitive to measure X-ray (linear) polarization for a broad range of cosmic sources-primarily those involving neutron stars, stellar black holes, and supermassive black holes (active galactic nuclei). We describe the technical basis, the mission concept, and the physical and astrophysical questions such a mission would address.

The Wide Field X-Ray Telescope (WFXT) will carry out an unprecedented X-ray survey of galaxy clusters and groups, AGNs and QSOs, and galaxies. WFXT is a medium-class strategic mission that will address key questions in both Cosmic Origins and Physics of the Cosmos. WFXT will be orders of magnitude more effective than previous X-ray missions in performing surveys to a given limiting flux. The angular resolution of ~5" will be finer than provided by any currently planned large-area X-ray survey and highly efficient at discriminating AGNs and QSOs from extended emission from sources such as galaxies and clusters. The Burrows, Burg and Giacconi ideal optical solution gives an approximately constant angular resolution of 3-5 arc seconds across a field of 1-1.5 degrees diameter. A preliminary telescope design provides a resulting grasp an order of magnitude larger than current or future missions. We plan a combination of three surveys and, at each flux limit, WFXT will cover orders of magnitude more area than all previous and planned missions, with the deep 100 deg² survey reaching the same flux limit as the deepest Chandra surveys to date. The WFXT mission addresses key cosmological and astrophysical science objectives including: the formation and evolution of clusters of galaxies with the associated cosmological and astrophysical implications; black hole formation and evolution; the interaction of black-hole driven AGNs with cluster and galaxy properties; and the high-energy stellar component and the hot ISM phase of galaxies WFXT is a mission for the entire astronomical community. The data from these surveys will be made readily available to the community in timely data releases to be used in a multitude of multi-waveband studies that will revolutionize astronomy.

Future astrophysics missions operating in the hard X-ray/Soft Gamma ray range is slated to carry novel focusing telescopes based on the use of depth graded multilayer reflectors. Current design studies show that, at the foreseen focal lengths, it should be feasible to focus X-rays at energies as high as 300 keV. These designs use extrapolations of theoretical and experimentally determined optical constants below 100 keV. We have previously shown that determining the optical constants from traditional single layer film above 40 keV is very difficult. One needs to have substrates which are very flat and it is very important to know the exact flatness. In this paper we report on the experimental determination of optical constants up to and above 130 keV using substrates with sub arcsecond flatness. We present these results as obtained at the National Synchrotron Light Source in Brookhaven and compare these to theoretically calculated values and previous experiments.

X-ray emission from charge exchange recombination between the highly ionized solar wind and neutral material in Earth's magnetosheath has complicated x-ray observations of celestial objects with x-ray observatories including ROSAT, Chandra, XMM-Newton, and Suzaku. However, the charge-exchange emission can also be used as an important diagnostic of the solar-wind interacting with the magnetosheath. Soft x-ray observations from low-earth orbit or even the highly eccentric orbits of Chandra and XMM-Newton are likely superpositions of the celestial object of interest, the true extra-solar soft x-ray background, geospheric charge exchange, and heliospheric charge exchange. We show that with a small x-ray telescope placed either on the moon, in a similar vein as the Apollo ALSEP instruments, or in a stable orbit at a similar distance from the earth, we can begin to disentangle the complicated emission structure in the soft x-ray band. Here we present initial results of a feasibility study recently funded by NASA to place a small x-ray telescope on the lunar surface. The telescope operates during lunar night to observe charge exchange interactions between the solar wind and magnetosphic neutrals, between the solar wind and the lunar atmosphere, and an unobstructed view of the soft x-ray background without the geospheric component.

Successfully developing and launching the next large X-ray observatory in a cost constrained environment will require a close partnership between scientists and engineers in academia, government and industry. We outline a set of design principles governing a sustainable development model that enables breakthrough scientific capability while maintaining credible commitment to tight cost constraints. We further aim for flexibility in a changing funding environment and responsiveness to new technology development. We bring in lessons learned from developing the Chandra X-ray observatory, the Lunar Crater Observation and Sensing Satellite (LCROSS) and include results of recent architecture studies. From the perspective of the builders of CGRO, Chandra and other high energy observatories, we summarize our progress towards a robust yet flexible development model that provides the highest probability for the next X-ray observatory to move from detailed concept studies to in orbit science operation.

The SuperAGILE experiment was launched on April 2007 onboard the Italian gamma-ray mission AGILE. With a field of view of approximately one steradian and an angular resolution of 6 arcmin, SuperAGILE is imaging the X-ray sky in two one-dimensional projections in the 18-60 keV energy range. After a ~2-month Commissioning Phase, SuperAGILE was set in its nominal configuration at the beginning of Science Verification Phase in July 2007 and it is observing the X-ray sky since then. In this paper we describe the in-orbit operations, the commissioning, science verification and inflight calibration phases, and provide a brief summary of the scientific observations carried out until June 2008.

The Minicalorimeter (MCAL) is a scintillation detector onboard the Italian space mission AGILE, dedicated to gamma-ray and hard-X astrophysics and launched on 23 April, 2007. MCAL can work both as part of the gamma-ray imaging system and as an independent detector for gamma-ray burst (GRB) in the 350 keV - 100 MeV energy range. The on-board trigger logic is now enabled for burst search on timescales as short as 64 ms, leading to a detection rate of about one event/week. MCAL is particularly suitable for the detection of short-hard bursts and contributes to GRB localization through the Inter-Planetary Network (IPN).

We report on the first results obtained from our development project of focusing gamma-rays (>60 keV) by using Laue lenses. The first lens prototype model has been assembled and tested. We describe the technique adopted and the lens focusing capabilities at about 100 keV.

The science drivers for a new generation soft gamma-ray mission are naturally focused on the detailed study of the acceleration mechanisms in a variety of cosmic sources. Through the development of high energy optics in the energy energy range 0.05-1 MeV it will be possible to achieve a sensitivity about two orders of magnitude better than the currently operating gamma-ray telescopes. This will open a window for deep studies of many classes of sources: from Galactic X-ray binaries to magnetars, from supernova remnants to Galaxy clusters, from AGNs (Seyfert, blazars, QSO) to the determination of the origin of the hard X-/gamma-ray cosmic background, from the study of antimatter to that of the dark matter. In order to achieve the needed performance, a detector with mm spatial resolution and very high peak efficiency is needed. The instrumental characteristics of this device could eventually allow to detect polarization in a number of objects including pulsars, GRBs and bright AGNs. In this work we focus on the characteristics of the focal plane detector, based on CZT or CdTe semiconductor sensors arranged in multiple planes and viewed by a side detector to enhance gamma-ray absorption in the Compton regime. We report the preliminary results of an optimization study based on simulations and laboratory tests, as prosecution of the former design studies of the GRI mission which constitute the heritage of this activity.

The study of Gamma-ray bursts (GRBs) is a key field to expand our understanding of several astrophysical and cosmological phenomena. SVOM is a Chinese-French Mission which will permit to detect and rapidly locate GRBs, in particular those at high redshift, and to study their multiwavelength emission. The SVOM satellite, to be launched in 2013, will carry wide field instruments operating in the X-/γ-ray band and narrow field optical and soft X-ray telescopes. Here we describe a small soft X-ray telescope (XIAO) proposed as an Italian contribution to the SVOM mission. Thanks to a grazing incidence X-ray telescope with effective area of ~120 cm² and a short focal length, coupled to a very compact, low noise, fast read out CCD camera, XIAO can substantially contribute to the overall SVOM capabilities for both GRB and non-GRB science.

The World Space Observatory - Ultraviolet (WSO-UV) is a space astronomy project led by Russia, with contributions from China, Germany, Italy, Spain, United Kingdom and a number of other countries in the world. WSO-UV consists of a 1.7-meter diameter telescope and three focal plane science instruments. The Long Slit Spectrograph instrument on-board WSO-UV will produce moderate spectral resolution (R=1000-2500) spectra in the 102nm ~ 320nm wavelength range along a slit of 75 arcsec in length and 1 arcsec in width. The spatial resolution of the instrument will be ~1 arcsec. A two-channel scheme is proposed to optimize performance, with each of these using a Rowland Circle optical design with Microchannel Plate detectors in the focal plane. We will discuss the detailed design of the spectrograph and its expected performance in this paper.

We are proposing an UV imaging spectro-polarimeter for the next UV space telescopes as WSO/UV. This instrument has been selected as one of the three channels, the Near-UV channel, of the Field Camera Unit at the focal plane of the WSO/UV telescope. Its optical design is based on a Wollaston prism followed by filters selecting the wavelength band and by a spherical mirror and an elliptical convex grating giving the spectral dispersion in the 150-280 nm wavelength range. This instrument allows a circular field of view of 1 arcmin with spatial resolution of 0.03 arcsec/pixel and low spectral resolution. Four different slitless operational modes will be possible: the imaging mode and the polarimetric mode, substituting the grating for an elliptical mirror and including or not the Wollaston prism, the spectral mode, excluding the Wollaston prism from the optical path, and the spectro-polarimetric mode, including all the optical elements in front of the entering radiation beam.

We explore the design of a space mission called Project Lyman that has the goal of quantifying the ionization history of the universe from the present epoch to a redshift of z ~ 3. Observations from WMAP and SDSS show that before a redshift of z (Symbol not available. See manuscript.) 6 the first collapsed objects, possibly dwarf galaxies, emitted Lyman continuum (LyC) radiation shortward of 912 Å that reionized most of the universe. Theoretical estimates of the LyC escape fraction ( f_esc ) required from these objects to complete reionization is f_esc ~10%. How LyC escapes from galactic environments, whether it induces positive or negative feedback on the local and global collapse of structures, and the role played by clumping, molecules, metallicity and dust are major unanswered theoretical questions, requiring observational constraint. Numerous intervening Lyman limit systems frustrate the detection of LyC from high z objects. They thin below z ~ 3 where there are reportedly a few cases of apparently very high fesc. At low z there are only controversial detections and a handful of upper limits. A wide-field multi-object spectroscopic survey with moderate spectral and spatial resolution can quantify f_esc within diverse spatially resolved galactic environments over redshifts with significant evolution in galaxy assemblage and quasar activity. It can also calibrate LyC escape against Lyα escape, providing an essential tool to JWST for probing the beginnings of reionization. We present calculations showing the evolution of the characteristic apparent magnitude of star-forming galaxy luminosity functions at 900 Å, as a function of redshift and assumed escape fraction. These calculations allow us to determine the required aperture for detecting LyC and conduct trade studies to guide technology choices and balance science return against mission cost. Finally we review our efforts to build a pathfinding dual order multi-object spectro/telescope with a (0.5°)² field-of-view, using a GSFC microshutter array, and crossed delay-line micro-channel plate detector.

The EURECA (EURopean-JapanEse Calorimeter Array) project aims to demonstrate the science performance and technological readiness of an imaging X-ray spectrometer based on a micro-calorimeter array for application in future X-ray astronomy missions, like Constellation-X and XEUS. The prototype instrument consists of a 5 × 5 pixel array of TES-based micro-calorimeters read out by by two SQUID-amplifier channels using frequency-domain-multiplexing (FDM). The SQUID-amplifiers are linearized by digital base-band feedback. The detector array is cooled in a cryogenfree cryostat consisting of a pulse tube cooler and a two stage ADR. A European-Japanese consortium designs, fabricates, and tests this prototype instrument. This paper describes the instrument concept, and shows the design and status of the various sub-units, like the TES detector array, LC-filters, SQUID-amplifiers, AC-bias sources, digital electronics, etc. Initial tests of the system at the PTB beam line of the BESSY synchrotron showed stable performance and an X-ray energy resolution of 1.58 eV at 250 eV and 2.5 eV @ 5.9 keV for the read-out of one TES-pixel only. Next step is deployment of FDM to read-out the full array. Full performance demonstration is expected mid 2009.

Several successful development programs have been conducted on Infra-Red bolometer arrays at the French Atomic Energy Commission (CEA-LETI Grenoble), in collaboration with the CEA-Sap (Saclay); taking advantage of this background, we are now developing an X-ray spectro-imaging camera for next generation space astronomy missions, using silicon technology. We have developed monolithic silicon micro-calorimeters based on implanted thermistors. These micro-calorimeter arrays will be used for future space missions. A 8×8 array prototype consisting of a grid of 64 suspended pixels on SOI (Silicon On Insulator) has been created. Each pixel of this array detector is made of a tantalum (Ta) absorber and is bonded, by means of an indium bump hybridization process, to a silicon thermistor. The absorber array is bound to the thermistor array in a collective process step. The fabrication process of our detector involves a combination of standard silicon technologies such as Si bulk micromachining techniques, based on deposition, photolithography and plasma etching steps. Finally, we present the results of measurements performed on the different building elements and processes that are required to create a detector array up to 32*32 pixels in size.

We are developing arrays of position-sensitive transition-edge sensor (PoST) X-ray detectors for future astronomy missions such as NASA's Constellation-X. The PoST consists of multiple absorbers thermally coupled to one or more transition-edge sensor (TES). Each absorber element has a different thermal coupling to the TES. This results in a distribution of different pulse shapes and enables position discrimination between the absorber elements. PoST's are motivated by the desire to achieve the largest possible focal plane area with the fewest number of readout channels and are ideally suited to increasing the Constellation-X focal plane area, without comprising on spatial sampling. Optimizing the performance of PoST's requires careful design of key parameters such as the thermal conductances between the absorbers, TES and the heat sink, as well as the absorber heat capacities. Our new generation of PoST's utilizes technology successfully developed on high resolution (~ 2.5 eV) single pixels arrays of Mo/Au TESs, also under development for Constellation-X. This includes noise mitigation features on the TES and low resistivity electroplated absorbers. We report on the first experimental results from new one-channel, four-pixel, PoST's or 'Hydras', consisting of composite Au/Bi absorbers. We have achieved full-width-at-half-maximum energy resolution of between 5-6 eV on all four Hydra pixels with an exponential decay time constant of 620 μs. Straightforward position discrimination by means of rise time is also demonstrated.

We devised and built a versatile facility for the calibration of the next generation X-ray polarimeters with unpolarized and polarized radiation. The former is produced at 5.9 keV by means of a Fe⁵⁵ radioactive source or by X-ray tubes, while the latter is obtained by Bragg diffraction at nearly 45 degrees. Crystals tuned with the emission lines of X-ray tubes with molybdenum, rhodium, calcium and titanium anodes are employed for the efficient production of highly polarized photons at 2.29, 2.69, 3.69 and 4.51 keV respectively. Moreover the continuum emission is exploited for the production of polarized photons at 1.65 keV and 2.04 keV and at energies corresponding to the higher orders of diffraction. The photons are collimated by means of interchangeable capillary plates and diaphragms, allowing a trade-off between collimation and high fluxes. The direction of the beam is accurately arranged by means of high precision motorized stages, controlled via computer so that long and automatic measurements can be done. Selecting the direction of polarization and the incidence point we can map the response of imaging devices to both polarized and unpolarized radiation. Changing the inclination of the beam we can study the systematic effects due to the focusing of grazing incidence optics and the feasibility of instruments with large field of view.

The development of micropixel gas detectors, capable to image tracks produced in a gas by photoelectrons, makes possible to perform polarimetry of X-ray celestial sources in the focus of grazing incidence X-ray telescopes. HXMT is a mission by the Chinese Space Agency aimed to survey the Hard X-ray Sky with Phoswich detectors, by exploitation of the direct demodulation technique. Since a fraction of the HXMT time will be spent on dedicated pointing of particular sources, it could host, with moderate additional resources a pair of X-ray telescopes, each with a photoelectric X-ray polarimeter (EXP², Efficient X-ray Photoelectric Polarimeter) in the focal plane. We present the design of the telescopes and the focal plane instrumentation and discuss the performance of this instrument to detect the degree and angle of linear polarization of some representative sources. Notwithstanding the limited resources, the proposed instrument can represent a breakthrough in X-ray Polarimetry.

An approach for measuring linear X-ray polarization over a broad-band using conventional spectroscopic optics is described. A set of multilayer-coated flats reflect the dispersed X-rays to the instrument detectors. The intensity variation as a function of energy and position angle is measured to determine three Stokes parameters: I, Q, and U. By laterally grading the multilayer optics and matching the dispersion of the gratings, one may take advantage of high multilayer reflectivities and achieve modulation factors over 80% over the entire 0.2 to 0.8 keV band. A sample design is shown that could be used with a small orbiting mission.

The Gas Pixel Detector (GPD) is a new generation device which, thanks to its 50 μm pixels, is capable of imaging the photoelectrons tracks produced by photoelectric absorption in a gas. Since the direction of emission of the photoelectrons is strongly correlated with the direction of polarization of the absorbed photons, this device has been proposed as a polarimeter for the study of astrophysical sources, with a sensitivity far higher than the instruments flown to date. The GPD has been always regarded as a focal plane instrument and then it has been proposed to be included on the next generation space-borne missions together with a grazing incidence optics. Instead in this paper we explore the feasibility of a new kind of application of the GPD and of the photoelectric polarimeters in general, i.e. an instrument with a large field of view. By means of an analytical treatment and measurements, we verify if it is possible to preserve the sensitivity to the polarization for inclined beams, opening the way for the measurement of X-ray polarization for transient astrophysical sources. While severe systematic effects arise for inclination greater than about 20 degrees, methods and algorithms to control them are discussed.

The X-ray Imaging Spectrometer (XIS) on board the Suzaku satellite is an X-ray CCD camera system that has features of a low background, high quantum efficiency, and good energy resolution in the 0.2 - 12 keV band. Because of the radiation damage, however, the energy resolution of the XIS has been degraded since Suzaku was launched (July 2005). One of the major advantages of the XIS over the other X-ray CCDs in orbit is the provision of a precision charge injection (CI) capability. In order to improve the energy resolution, the precise measurement of charge transfer inefficiency (CTI) is essential. For this purpose, we applied the checker-flag CI, and we were able to measure the CTI of each CCD column. Furthermore, we were able to obtain the pulse height dependency of the CTI. Our precise CTI correction using these results improved the energy resolution from 193 eV to 173 eV in FWHM at 5.9 keV in July 2006 (one year after the launch). The energy resolution can be improved also by reducing the CTI. For this purpose, we applied the spaced-row charge injection (SCI); periodically injected artificial charges work as if they compensate radiation-induced traps and prevent electrons produced by X-rays from being captured by the charge traps. Using this method, the energy resolution improved from 210 eV to 150 eV at 5.9 keV in September 2006, which is close to the resolution just after the launch (145 eV). We report the current in-orbit calibration status of the XIS data using these two techniques. We present the time history of the gain and energy resolution determined from onboard calibration sources (⁵⁵Fe) and observed calibration objects like E0102-72.

Since the launch of the Suzaku X-ray astronomy satellite into low- earth orbit in July, 2005, the performance of the CCD detectors in the X-ray Imaging Spectrometer (XIS) detectors have slowly degraded, as expected, due to accumulating radiation damage. We compare the evolution of front- and back-illuminated XIS CCDs with one another and with that of very similar detectors installed in the ACIS instrument aboard the Chandra X-ray Observatory, which is in a much higher orbit than Suzaku. We attempt to identify effects of the differing radiation environments as well as those arising from structural differences between the two types of detector.

We are planning to have a "formation flight all sky telescope"~(FFAST) that will cover a large sky area in relatively high energy X-ray. In particular, it will focus on the energy range above 10 keV. It consists of two small satellites that will go in a formation flight. One is an X-ray telescope satellite and the other is a detector satellite. Two satellites will be simultaneously launched by a single rocket vehicle into a low earth orbit. They are in a formation flight with a separation of 20m±10cm. The observation direction is determined by the two satellites. Since two satellites are put into Keplerian orbit, the observation direction is scanning the sky rather than pointing to a fixed direction. The X-ray telescope satellite carries one super-mirror covering the energy range up to 80 keV. The telescope is 45-cm diameter and its focal length is 20m. The telescope is a "super mirror" ~that has a multi-layer coating covering the energy range up to 80 keV. The effective area is about 500cm² at low energy and 200cm² at 70 keV. The mirror system is a thin foil mirror that is developing at Nagoya University that is being developed. The PSF of the mirror will be about 1-2 arcmin. The satellite is equipped with an attitude control system using momentum wheel. It will keep the satellite such that the optical axis of the mirror is pointing to the detector satellite. The other is a detector satellite that carries an SDCCD system. The SDCCD is a CCD with a scintillator that is directly attached to the CCD. The CCD chip is fully depleted which can be a back-illuminated CCD. The scintillator is attached to the CCD at back side so that it has high detection efficiency for visible photons generated inside the scintillator. The X-ray enters into the CCD at front side. Therefore, low energy X-rays (below 10 keV) can be photo-absorbed in the depletion layer of the CCD while high energy X-rays will be absorbed in the scintillator that will emit visible photons The visible photons can be detected by the CCD. Depletion layer events usually form small charge spread while scintillator events usually form large charge spread. These events generate charge spread in a symmetric form with different size. On the contrary, charged particles leave an elongated charge spread that can be distinguished from X-ray events by pattern recognition. This project, Formation Flight All Sky Telescope (FFAST), will scan a large sky area at hard X-ray region.

The flight calibration of the spectral response of CCD instruments below 1.5 keV is difficult in general because of the lack of strong lines in the on-board calibration sources typically available. We have been using E0102, the brightest supernova remnant in the Small Magellanic Cloud, to evaluate the response models of the ACIS CCDs on the Chandra X-ray Observatory (CXO), the EPIC CCDs on the XMM-Newton Observatory, the XIS CCDs on the Suzaku Observatory, and the XRT CCD on the Swift Observatory. E0102 has strong lines of O, Ne, and Mg below 1.5 keV and little or no Fe emission to complicate the spectrum. The spectrum of E0102 has been well characterized using high-resolution grating instruments, namely the XMM-Newton RGS and the CXO HETG, through which a consistent spectral model has been developed that can then be used to fit the lower-resolution CCD spectra. Fits with this model are sensitive to any problems with the gain calibration and the spectral redistribution model of the CCD instruments. We have also used the measured intensities of the lines to investigate the consistency of the effective area models for the various instruments around the bright O (570 eV and 654 eV) and Ne (910 eV and 1022 eV) lines. We find that the measured fluxes of the O VII triplet, the O VIII Ly-a line, the Ne IX triplet, and the Ne X Ly-a line generally agree to within ±10% for all instruments, with 28 of our 32 fitted normalizations within ±10% of the RGS-determined value. The maximum discrepancies, computed as the percentage difference between the lowest and highest normalization for any instrument pair, are 23% for the O VII triplet, 24% for the O VIII Ly-a line, 13% for the Ne IX~triplet, and 19% for the Ne X Ly-a line. If only the CXO and XMM are compared, the maximum discrepancies are 22% for the O VII triplet, 16% for the O VIII Ly-a line, 4% for the Ne IX triplet, and 12% for the Ne X Ly-a line.

The Solar X-ray Imager (SXI) was launched 24 May 2006 on Geostationary Operational Environmental Satellite (GOES-13). SXI is a grazing incidence X-ray telescope that focuses an image of the Sun onto a CCD detector through a set of selectable filters. The X-ray image data are transmitted at the rate of at least one image per minute, which permits the reconstruction of near-real-time solar images in the 6-60Å range (photon energy 2000-200 eV). Thin film filters consisting of aluminum, titanium, and polyimide are used in the entrance of the telescope to eliminate visible light. During the first six months of on-orbit operations the amount of stray light transmitted increased approximately linearly with time, consistent with the formation of small (less than 50 micron) pinholes. A laboratory investigation was initiated and witness sample filters were subjected to energetic particles simulating the on-orbit radiation environment and their quality was assessed using visible light-leak testing and scanning electron microscope imaging. It was concluded that galvanic corrosion of aluminum and titanium initiates pinholes that subsequently grow in dendritic fashion by spalling off of aluminum to relieve the internal film stress. The test program also revealed that the geostationary radiation dose level can damage polyimide and lead to filter failure. Radiation damage may have been responsible in part for the increased light levels observed in the GOES-12 SXI and with increased exposure a similar observation could manifest on GOES-13 SXI. This paper presents the methodology and results for the entrance filter test program for the GOES SXI telescopes and presents recommended improvements for future instruments.

Reaching a low-level and well understood internal instrumental background is crucial for the scientific performance of an X-ray detector and, therefore, a main objective of the instrument designers. Monte-Carlo simulations of the physics processes and interactions taking place in a space-based X-ray detector as a result of its orbital environment can be applied to explain the measured background of existing missions. They are thus an excellent tool to predict and optimize the background of future observatories. Weak points of a design and the main sources of the background can be identified and methods to reduce them can be implemented and studied within the simulations. Using the Geant4 Monte-Carlo toolkit, we have created a simulation environment for space-based detectors and we present results of such background simulations for XMM-Newton's EPIC pn-CCD camera. The environment is also currently used to estimate and optimize the background of the future instruments Simbol-X and eRosita.

We report on the development of high-speed and low-noise readout system of X-ray CCD camera with ASIC and the Camera Link standard. The ASIC is characterized by AD-conversion capability and it processes CCD output signals with a high pixel rate of 600 kHz, which is ten times quicker than conventional frame transfer type X-ray CCD cameras in orbit. There are four identical circuits inside the chip and all of them process CCD signals simultaneously. ΔΣ modulator is adopted to achieve effective noise shaping and obtain a high resolution decimal values with relatively simple circuits. The results of the unit test shows that it works properly with moderately low input noise of ~70 μV at pixel rate of 625 kHz, and ~40 μV @ 40 kHz. Power consumption is sufficiently low of <120 μuV @ 1.25 MHz. We have also developed the rest of readout and driving circuits. As a data acquisition scheme we adopt the Camera Link standard in order to support the high readout rate of the ASIC. In the initial test of the CCD camera system, we used the P-channel CCD developed for Soft X-ray Imager onboard next Japanese X-ray astronomical satellite. The thickness of its depletion layer reaches up to 220 μm and therefore we can detect the X-rays from ¹⁰⁹Cd with high sensitivity rather than N-channel CCDs. The energy resolution by our system is 379 (±7)eV (FWHM) @ 22.1 keV, that is, ΔE/E=1.8% was achieved with a readout rate of 44 kHz.

This paper presents critical engineering aspects of a grating array for a sub-orbital rocket payload to make spectral observations in the soft X-ray regime. The off-plane grating mount is a natural solution to maximize throughput and resolution in the 1/4 keV to 1 keV range while minimizing envelope and mass. Replicated radial groove gratings are matched to the convergence angle of the telescope beam to limit aberrations. These lightweight gratings are mounted and aligned in an array which is not only efficient for rocket payloads, but can also be made suitable for the X-ray Grating Spectrometer on Constellation X.

The Soft X-ray Spectrometer (SXS) onboard the NeXT (New exploration X-ray Telescope) is an X-ray spectrometer utilizing an X-ray microcalorimeter array. Combined with the soft X-ray telescope of 6 m focal length, the instrument will have a ~ 290cm² effective at 6.7 keV. With the large effective area and the energy resolution as good as 6 eV (FWHM), the instrument is very suited for the high-resolution spectroscopy of iron K emission line. One of the major scientific objectives of SXS is to determine turbulent and/or macroscopic motions of the hot gas in clusters of galaxies of up to z ~ 1. The instruments will use 6 × 6 or 8 × 8 format microcalorimeter array which is similar to that of Suzaku XRS. The detector will be cooled to a cryogenic temperature of 50 mK by multi-stage cooling system consisting of adiabatic demagnetization refrigerator, super fluid He, a 3He Joule Thomson cooler, and double-stage stirling cycle cooler.

The Soft X-ray Imager (SXI) is the X-ray CCD detector system on board the NeXT mission that is to be launched around 2013. The system consists of a camera, an SXI-specific data processing unit (SXI-E) and a CPU unit commonly used throughout the NeXT satellite. All the analog signal handling is restricted within the camera unit, and all the I/O of the unit are digital. The camera unit and SXI-E are connected by multiple LVDS lines, and SXI-E and the CPU unit will be connected by a SpaceWire (SpW) network. The network can connect SXI-E to multiple CPU units (the formal SXI CPU and neighbors) and all the CPU units in the network have connections to multiple neighbors: with this configuration, the SXI system can work even in the case that one SpW connection or the formal SXI CPU is down. The main tasks of SXI-E are to generate the CCD driving pattern, the acquisition of the image data stream and HK data supplied by the camera and transfer them to the CPU unit with the Remote Memory Access Protocol (RMAP) over SpW. In addition to them, SXI-E also detects the pixels whose values are higher than the event threshold and both adjacent pixels in the same line, and send their coordinates to the CPU unit. The CPU unit can reduce its load significantly with this information because it gets rid of the necessity to scan whole the image to detect X-ray events.

Monitor of All-sky X-ray Image (MAXI) is an X-ray all-sky monitor, which will be delivered to the International Space Station (ISS) by a space shuttle crew in early 2009, to scan almost the entire sky once every 96 minutes for a mission life of two to five years. The detection sensitivity will be 5 mCrab (5σlevel) for a one-day MAXI operation, 2 mCrab for one week, and 1 mCrab for one month, reaching a source confusion limit of 0.2 mCrab in two years. In this paper, brief descriptions are presented for the MAXI mission and payload, and three operation phases, 1) the launch-to-docking phase, 2) the initial in-orbit calibration phase, and 3) the routine operation phase. We also describes the MAXI data product and its release plan for public users.

We present a plan on soft X-ray calibration for the New Exploration X-ray Telescope (NeXT). Two hard and two soft X-ray telescopes (HXTs/SXTs: see Ogasaka et al. 2008 in this volume) provide images up to 80 keV with a large effective area. Following to the Suzaku X-ray telescope, the mirrors on SXTs are tightly nested to maximize the aperture efficiency. To illuminate the mirrors at all, we plan to adopt a raster scan system using a pencil beam collimated from an X-ray generator. We summarize a current status of the soft X-ray ground calibration system at ISAS/JAXA. We also review the calibration of the Suzaku XRTs since the optics are very similar to the NeXT SXTs.

We present a plan for calibration of the NeXT hard X-ray telescopes (HXT) at the synchrotron radiation facility, SPring-8. In hard X-rays, it is difficult for a laboratory-based beamline using a conventional X-ray source to provide sufficient capabilities for pre-flight high-precision calibration. Therefore, we plan to characterize the NeXT HXT at the SPring-8 beamline BL20B2. SPring-8 is one of the world's third-generation synchrotron radiation facilities. Measurements at BL20B2 have great advantages over those done with conventional sources, such as an extremely high flux, a larger beam with less divergence, and a selectable, narrow bandwidth covering the hard X-ray region from 8 to over 100 keV. The 16m-long experimental hutch has sufficient capability for characterization of the NeXT HXT (FL=12m). In the past, we have measured the Point Spread Function (PSF) and effective area of telescopes for balloon-borne hard X-ray imaging experiments (e.g. InFOCuS, SUMIT) at several energies from 20 to 60 keV. Furthermore, we have successfully established a tuning procedure to improve their image quality. We plan to measure the X-ray characteristics (PSF, effective area, stray light, and so on) of the NeXT HXT to build up the HXT response function.

We present a study on housing design for the X-ray telescopes (XRT) onboard the New Exploration X-ray Telescope (NeXT). The NeXT XRTs are larger than previous thin-foil XRTs. The XRT is required to have a sufficient stiffness in order to keep the high performance of the XRT in orbit. We performed a structure analysis of the virtual model of the NeXT XRT housing using the FEA software Marc. A virtual model of the NeXT XRT was designed based on the XRT of the SUMIT balloon experiment. From the structure analysis of the virtual model by Marc, we found that the displacement of the XRT housing is small. The maximum displacement is a few µm, which is satisfied with our goal of 10 µm. On the other hand, the alignment bars show a large displacement up to about 90 µm. This is caused because the alignment bars become longer, and the total weight of the thin foils increases due to the larger effective area. This analysis indicates that we have to use stiff alignment bars without reducing the effective area. This result is useful to design a proto-model of the XRT housing. We will examine the result of this FEA analysis by measuring the displacement of the proto-model.

MAXI (Monitor of All-sky X-ray Image) is a payload on board the International Space Station, and will be launched on April 2009. We report on the current development status on MAXI, in particular on the two types of X-ray camera (GSC and SSC), and the simulation results of the MAXI observation. SSC is a CCD camera. The moderate energy resolution enables us to detect the various emission peak including 0.5 keV oxygen line. The averaged energy resolution at the CCD temperature of -70 deg is 144.5 eV (FWHM) for 5.9 keV X-ray. GSC includes proportional gas counters, which have large X-ray detection area (5350cm²). The averaged position resolution of 1.1mm at 8 keV enable us to determined the celestial position of bright sources within the accuracy of 0.1 degree. The simulation study involving the results of performance test exhibits the high sensitivity of MAXI as designed.

This paper describes the conceptual thermo-mechanical design of the MIXS (Mercury Imaging X-ray Spectrometer) Focal Plane Assembly (FPA). This design is mainly driven by thermal requirements: The Detector is required to operate below -45 ºC, while the Detector and proximity electronics dissipate more than 2 W, which the passive cooling system can not handle at the required temperature. In order to get rid of this cross-constraint, the Detector was separated from the Proximity electronics board, which in turn has introduced a new dimension of mechanical requirements, as the 370+ bond wires that interconnect both are extremely delicate and have a high thermal conductivity.

MPE will provide the X-ray Survey Telescope eROSITA [5] for the Russian Spektrum-Roentgen-Gamma Mission [4] to be launched in 2011. The design of the X-ray mirror system is based on that of ABRIXAS: The bundle of 7 mirror modules with the short focal length of 1600 mm makes it still a compact instrument while, however, its sensitivity in terms of effective area, field-of-view, and angular resolution shall be largely enhanced with respect to ABRIXAS. The number of nested mirror shells increases from 27 to 54 compared to ABRIXAS thus enhancing the effective area in the soft band by a factor of six. The angular resolution is targeted to be 15 arc seconds half-energy width (HEW) on-axis resulting in an average HEW of 26 arc seconds over the 61 arc minutes field-of-view (FoV). The instrument's high grasp of about 1000 cm²deg² in the soft spectral range and still 10 cm²deg² at 10 keV combined with a survey duration of 4 years will generate a new rich database of X-ray sources over the whole sky. As the 7 mirror modules are co-aligned eROSITA is also able to perform pointed observations.

Three of the four detectors of the SphinX experiment to be flown on the Russian mission Coronas-Photon have been measured at the XACT Facility of the Palermo Observatory at several wavelengths in the soft X-ray band. We describe the instrumental set-up and report some measurements. The analysis work to obtain the final calibration is still in progress.

The Simbol-X¹ Low Energy Detector (LED), a 128 × 128 pixel DEPFET array, will be read out very fast (8000 frames/second). This requires a very fast onboard data preprocessing of the raw data. We present an FPGA based Event Preprocessor (EPP) which can fulfill this requirements. The design is developed in the hardware description language VHDL and can be later ported on an ASIC technology. The EPP performs a pixel related offset correction and can apply different energy thresholds to each pixel of the frame. It also provides a line related common-mode correction to reduce noise that is unavoidably caused by the analog readout chip of the DEPFET. An integrated pattern detector can block all invalid pixel patterns. The EPP has an internal pipeline structure and can perform all operation in realtime (< 2 μs per line of 64 pixel) with a base clock frequency of 100 MHz. It is utilizing a fast median-value detection algorithm for common-mode correction and a new pattern scanning algorithm to select only valid events. Both new algorithms were developed during the last year at our institute.

We present the design of the pre-collimator for the X-ray telescopes (XRTs) onboard New X-ray Telescope (NeXT). The optical design adopted for the NeXT XRTs is conically-approximated Wolter-I type optics. The tightly-nested reflectors with thin substrates (150-300 μm) enable us to achieve the large effective area and extremely light weight simultaneously. However, due to the packed reflector shells, X-rays from the outside of the XRT field of view occasionally arrive at the focal plane without the normal double reflection (stray lights), and then produce a ghost image on the detector. Thus, the stray-lights contamination degrades sensitivity of the source detection In order to reduce the stray lights efficiently, we plan to mount a collimator onto each telescope (referred to as pre-collimator), which is similar to that equipped with the Suzaku XRTs. The pre-collimator consists of coaxially-nested cylindrical blades, each of which is aligned radially with the corresponding primary refector. We found the height of the pre-collimator blade to be ~100 mm that is required to block the X-rays with off-axis angles of 30'-50', which are the main ligth pass of the stray lights for the NeXT XRTs.

The New Exploration X-ray Telescope (NeXT) is an X-ray astronomical observatory slated to be launched from Japan in 2013. Its objectives range from high resolution imaging and spectroscopy below ~12 keV to studying the hard X-ray sky up to ~70 keV. To accomplish these goals, it will carry, among other instruments, 4 grazing incidence, imaging telescopes, two covering the soft X-ray band and the remaining the higher energies. The soft X-ray telescopes will be similar to ones flown onboard Suzaku, with a larger outer diameter (45 cm) and longer focal length (6 m). The NASA's GSFC foil mirror group is collaborating with the Nagoya University and ISAS/JAXA in the implementation of the the soft X-ray mirrors. Our science driven goal is a <1.3' Half Power Diameter (HPD) Point Spread Function, improved from Suzaku ~1.7' HPD. We address important area in the fabrication process where we plan to make changes; (1) substrate shaping, (2) replication process, (3) reflector assembly, (4) alignment bar accuracy, and (5) focal length miss match among segments. Having done some of them, we measured 1.26' HPD for 60-pair quadrant reflectors. But it still includes bad sectors (>1.8' HPD) towards the quadrant boundary, while most of middle sectors are at 1' HPD level. The bad sectors can be corrected with new assembly approach where we actively tune and then fix reflectors at their right position or whole conical shell reflectors instead of segmented ones. In this proceeding, we present a proposed NeXT soft X-ray telescope performance, report the current status of the development and introduce the new whole shell mirror.

Minimization of charged particle background in X-ray telescopes is a well known issue. Charged particles (chiefly protons and electrons) naturally present in the cosmic environment constitute an important background source when they collide with the X-ray detector. Even worse, a serious degradation of spectroscopic performances of the X-ray detector was observed in Chandra and Newton-XMM, caused by soft protons with kinetic energies ranging between 100 keV and some MeV being collected by the grazing-incidence mirrors and funneled to the detector. For a focusing telescope like SIMBOL-X, the exposure of the soft X-ray detector to the proton flux can increase significantly the instrumental background, with a consequent loss of sensitivity. In the worst case, it can also seriously compromise the detector duration. A well-known countermeasure that can be adopted is the implementation of a properly-designed magnetic diverter, that should prevent high-energy particles from reaching the focal plane instruments of SIMBOL-X. Although Newton-XMM and Swift-XRT are equipped with magnetic diverters for electrons, the magnetic fields used are insufficient to effectively act on protons. In this paper, we simulate the behavior of a magnetic diverter for SIMBOL-X, consisting of commercially-available permanent magnets. The effects of SIMBOL-X optics is simulated through GEANT4 libraries, whereas the effect of the intense required magnetic fields is simulated along with specifically-written numerical codes in IDL.

Test campaign of mirror shells for eROSITA, to be launched in 2011, has been performed at the PANTER X-ray test facility. The results of the campaign are adequately described in our companion paper. In this paper, we focus on the detailed analysis of intra- and extrafocal images to investigate possible outcome of the out-of-focus measurements in the framework of the eROSITA mirror test programme. The images taken at several out-offocus positions are ring-shaped, that provide crucial keys to the understanding of the optics performance. With those out-of-focus rings, we can easily examine where the deformation occurs on the shell. Conceivable error causes of the image degradation are examined quantitatively. Properties of the in-focus image can be predicted by an interpolation of the out-of-focus rings, a kind of "Hartmann test". Performing Hartmann test, we can estimate how large portion of the image degradation can be attributed to the out-of-roundness error which is mainly due to fluctuations in taper angles. The reconstructed image using Hartmann test appears similar to the core of actual in-focus image. We also pursue the possibility to evaluate the contributions of slope errors using the width of the radial profiles of the out-of-focus rings. These diagnostic techniques with the out-of-focus measurements should be useful for future measurements, not only for the eROSITA mirror but also for other missions (e.g. XEUS optics), where the images are only available at out-of-focus positions in PANTER facility (i.e. impossible to take in-focus images) because of the significantly long focal lengths.

We report on the prospects for the study of the first stars, galaxies and black holes with the Generation-X Mission. Generation-X is a NASA "Vision Mission" which completed preliminary study in lat e2006. Generation-X was approved in February 2008 as an Astrophysics Strategic Mission Concept Study (ASMCS) and is baselined as an X-ray observatory with 50 square meters of collecting area at 1 keV (500 times larger than Chandra) and 0.1 arcsecond angular resolution (several times better than Chandra and 50 times better than the Constellation-X resolution goal). Such a high energy observatory will be capable of detecting the earliest black holes and galaxies in the Universe, and will also study the chemical evolution of the Universe and extremes of density, gravity, magnetic fields, and kinetic energy which cannot be created in laboratories. A direct signature of the formation of the first galaxies, stars and black holes is predicted to be X-ray emission at characteristic X-ray temperatures of 0.1-1 keV from the collapsing proto-galaxies before they cool and form the first stars.

Stellar Imager (SI) is a proposed NASA space-based UV imaging interferometer to resolve the stellar disks of nearby stars. SI would consist of 20 - 30 separate spacecraft flying in formation at the Earth-Sun L2 libration point. Onboard wavefront sensing and control is required to maintain alignment during science observations and after array reconfigurations. The Fizeau Interferometry Testbed (FIT), developed at the NASA/Goddard Space Flight Center, is being used to study wavefront sensing and control methodologies for Stellar Imager and other large, sparse aperture telescope systems. FIT initially consists of 7 articulated spherical mirrors in a Golay pattern, and is currently undergoing expansion to 18 elements. FIT currently uses in-focus whitelight sparse aperture PSFs and a direct solve broadband phase retrieval algorithm to sense and control its wavefront. Ultimately it will use extended scene wavelength, with a sequential diversity algorithm that modulates a subset of aperture pistons to jointly estimate the wavefront and the reconstructed image from extended scenes. The recovered wavefront is decomposed into the eigenmodes of the control matrix and actuators are moved to minimize the wavefront piston, tip and tilt in closed-loop. We discuss the testbed, wavefront control methodology and ongoing work to increase its bandwidth from 1 per 11 seconds to a few 10's of Hertz and show ongoing results.

We are developing grazing-incidence x-ray optics for high-energy astrophysics using an electroform-nickel process in which mirror shells are formed by replication off super-polished cylindrical mandrels. The optics so fabricated have a demonstrated performance at the level of 11-12 arc seconds resolution (HPD) for 30 keV x rays. Future missions, however, demand ever higher angular resolutions and this places stringent requirements on all aspects of the process -- the mandrels, the shell fabrication, and the mounting and alignment of the resulting mirrors in their housings. A progress report on recent technology developments in these areas is given, including a discussion on possible post fabrication improvements in the x-ray mirrors' quality.

The Constellation-X Spectroscopy X-ray Telescope (SXT) is a segmented, tightly nested Wolter-I telescope with a requirement of approximately 12.5 arcseconds HPD for the mirror system. The individual mirror segments are 0.4 mm thick, formed glass, making the task of mounting, alignment and bonding extremely challenging. Over the past year we have developed a series of tools to meet these challenges, the latest of which is an upgrade to the 600-meter x-ray beam line at GSFC. The new facilities allow us to perform full aperture and sub-aperture imaging tests of mirror segment pairs to locate the source of deformations and correlate them with our optical metrology. We present the optical metrology of the axial figure and Hartmann focus, x-ray imaging performance predictions based on analysis of the optical metrology, and both full aperture and sub-aperture x-ray imaging performance of test mirror segment pairs at 8.05 keV.

The design of a grazing incidence focusing optic obtained from a spiral approximation to multiple nested cones produces an annular image of a point source. The angular size of the annulus depends mainly on the pitch of the winding and the focal length. For a spiral conical approximation to Wolter optics, the effect is magnified by the double reflection. However, if the two conical spirals are wound one clock-wise and the other counter-clock-wise, then the aberration is partially compensated. We use a ray tracing code to evaluate advantages and disadvantages of this optical design for potential applications of a light weight optics technology based on plastic foils that we are currently investigating.

More X-ray missions that will be operating in near future, like particular SIMBOL-X, e-Rosita, Con-X/HXT, SVOM/XIAO and Polar-X, will be based on focusing optics manufactured by means of the Ni electroforming replication technique. This production method has already been successfully exploited for SAX, XMM and Swift-XRT. Optical surfaces for X-ray reflection have to be as smooth as possible also at high spatial frequencies. Hence it will be crucial to take under control microroughness in order to reduce the scattering effects. A high rms microroughness would cause the degradation of the angular resolution and loss of effective area. Stringent requirements have therefore to be fixed for mirror shells surface roughness depending on the specific energy range investigated, and roughness evolution has to be carefully monitored during the subsequent steps of the mirror-shells realization. This means to study the roughness evolution in the chain mandrel, mirror shells, multilayer deposition and also the degradation of mandrel roughness following iterated replicas. Such a study allows inferring which phases of production are the major responsible of the roughness growth and could help to find solutions optimizing the involved processes. The exposed study is carried out in the context of the technological consolidation related to SIMBOL-X, along with a systematic metrological study of mandrels and mirror shells. To monitor the roughness increase following each replica, a multiinstrumental approach was adopted: microprofiles were analysed by means of their Power Spectral Density (PSD) in the spatial frequency range 1000-0.01 μm. This enables the direct comparison of roughness data taken with instruments characterized by different operative ranges of frequencies, and in particular optical interferometers and Atomic Force Microscopes. The performed analysis allowed us to set realistic specifications on the mandrel roughness to be achieved, and to suggest a limit for the maximum number of a replica a mandrel can undergo before being refurbished.

It is well known that slope errors introduced by warped profiles in X-ray Wolter-I astronomical mirrors are important for the image quality at the focal plane. At this regard, a study aiming at developing reliable methods to predict the image quality on the basis of measured profiles of mandrels and mirror shells replicated by Ni electroforming has been performed. We are interested in determinating which of the different available methods could be trusted. The image quality is studied in terms of the Half Energy Width (HEW), a parameter in principle predictable from the metrological data. Two main approaches have been employed to calculate the HEW: i) ray-tracing, that follows the path of every generated photon from the source to the focus after the reflection onto a surface generated by the measured profiles; ii) the so called δ50 (delta 50) method, i.e. considering the slope errors distribution coming from the difference between Wolter profile and measured profile. The analysis is performed by means of software packages specifically written for this aim. They allowed us to consider 2D longitudinal profiles or a 3D grid composed of longitudinal and azimuthal profiles. Analysed profiles belong to mandrels and mirror-shells developed during the feasibility studies of the SIMBOLX and eRosita missions. The data were taken by means of profilometers during the several phases of their manufacturing. Monitoring the HEW evolution was investigated also in order to understand possible errors introduced during the replica and integration process, and to understand effects visible in focal spot and PSF's at the best focus or at different sections along the optical axis.

We exploited a ray-tracing Montecarlo code to investigate the effects of stray-light on the performances of the Wide Field Imager (FoV = 1.5 deg) on board the EDGE satellite. We found non negligible stray-light contamination up to ~ 8 deg off-axis angles. We discuss the benefits of a baffle in order to reduce this contamination, that would strongly affect the telescope sensitivity, and present two possible baffle designs based on results of simulations.

We have developed an Electron-Tracking Compton Camera (ETCC) based on a gaseous micro Time Projection Chamber (ETCC) based on a gaseous micro Time Projection Chamber (μ-TPC) which measures the direction and the energy of the recoil electron and a GSO(Ce) scintillation camera which surrounds the μ-TPC and measures the Compton scattered gamma ray. If not measuring a direction of a recoil electron, a direction of the incident gamma-ray could only be reconstructed as a circle. Measuring the direction of the recoil electron reduces the Compton cone to a point, and thus reconstructs the incident direction completely for a single photon and realizes the strong background rejection. Using the ETCC with a detection volume of about 10cm×10cm×15cm, we had the balloon-borne experiment supported by ISAS/JAXA in 2006 for the purpose of the observation of diffuse cosmic and atmospheric gamma rays. The ETCC obtained about 200 photons with FOV of 3 str in 3 hours in the energy range from 100 keV to 1 MeV, and the obtained flux was consistent with previous observations. On the basis of the results, we are developing the large size ETCC in order to improve the effective area for the next balloon experiment. The large size ETCC has the detection volume of 23cm ×28cm×30cm which consists of the 23cm×28cm×30cm μ-TPC and the 30cm×30cm×1.3cm scintillation camera. Then we obtained the gamma-ray image and investigated the first performances of the large size ETCC. The Angular Resolution Measure (ARM) and the Scatter Plane Deviation (SPD) are 12.1 degree and 117 degree (FWHM) at 662keV, respectively, and the energy resolution is 16.9%(FWHM) at 662keV.

SuperAGILE (SA) is the hard X-ray monitor of the AGILE small satellite mission, launched on 23^rd April 2007. The monitor is based on four one-dimensional coded-mask detectors. In spite of the compactness (45×45×15 cm³) and lightness (5 kg), the experiment has high angular resolution (6 arcmin) and point source location accuracy (<2 arcmin, for bright sources) for every position in the Field Of View (FOV). To achieve these imaging performances, considerable efforts were made for the alignment procedures during the assembly of the experiment itself, and with the rest of the satellite. Mechanical alignment were measured during all the assembly phases and before the launch campaign. Moreover, a specific campaign was performed in the laboratory with radioactive calibration sources to calibrate the imaging response on ground. A on-orbit calibration campaign was performed using the Crab Nebula. Due to the huge satellite wobbling (1 deg) and continuous slewing (1 deg/day), a refined attitude correction strategy has been implemented on photon-by-photon data to maintain the high imaging performances. In this paper we summarize all the activities we performed for calibrating and optimizing the imaging capabilities, from the assembly of the experiment to the on-orbit calibrations and we show the results achieved.

AGILE is an ASI (Italian Space Agency) Small Scientific Mission dedicated to high-energy astrophysics which was launched on April 23 2007 from Satish Dawan Space Centre (India) on a PSLV-C8 rocket. The AGILE Payload is composed of three instruments: a Tungsten-Silicon Tracker designed to detect and image photons in the 30 MeV-50 GeV energy band, an X-ray imager called SuperAGILE that works in the 18-60 keV energy band, and a Minicalorimeter that detects gamma-rays or particle energy deposits between 300~keV and 200~MeV. The instrument is surrounded by an anti-coincidence (AC) system. We have developed a set of Quick Look software tools in the framework of the Test Equipment (TE) and the Electrical Ground Support Equipment (EGSE. This s/w is required in order to support all the assembly, integration and verification (AIV) activities to be carried out for the AGILE mission, from data handling unit level to payload integrated level, calibration campaign, launch campaign and in-orbit commissioning. These software tools have enabled us to test the engineering performance and to perform a health check of the Payload during the various phases. We have used an incremental development approach and a common framework to rapidly adapt our software to the different requirements of the various phases.

AGILE is an ASI (Italian Space Agency) Small Space Mission for high energy astrophysics in the range 30 MeV - 50 GeV successfully launched on 23 April 2007 and currently fully operative. The on-ground Gamma Ray calibration of the Payload have been carried out 18 months before launch at the Beam Test Facility - INFN LNF (Roma) using a complement of mechanical and electrical equipment and computer systems specifically developed to that purpose. In particular, a specific software has been designed and developed to automate the operations of the Mechanical Ground Support Equipment (MGSE) which positions the Payload in front of the Beam. In this paper the architecture and the performance of the software will be described and discussed.

AGILE is an Italian Space Agency (ASI) satellite dedicated to high energy Astrophysics. It was launched successfully on 23 April 2007, and it has been operated by the AGILE Ground Segment, consisting of the Ground Station located in Malindi (Kenia), the Mission Operations Centre (MOC) and the AGILE Data Centre (ADC) established in Italy, at Telespazio in Fucino and at the ASI Science Data Centre (ASDC) in Frascati respectively. Due to the low equatorial orbit at ~ 530 Km. with inclination angle of ~ 2.5°, the satellite passes over the Ground Station every ~ 100'. During the visibility period of . ~ 12', the Telemetry (TM) is down linked through two separated virtual channels, VC0 and VC1. The former is devoted to the real time TM generated during the pass at the average rate of 50 Kbit/s and is directly relayed to the Control Centre. The latter is used to downlink TM data collected on the satellite on-board mass memory during the non visibility period. This generates at the Ground Station a raw TM file of up to 37 MByte. Within 20' after the end of the contact, both the real time and mass memory TM arrive at ADC through the dedicated VPN ASINet. Here they are automatically detected and ingested by the TMPPS pipeline in less than 5 minutes. The TMPPS archives each TM file and sorts its packets into one stream for each of the different TM layout. Each stream is processed in parallel in order to unpack the various telemetry field and archive them into suitable FITS files. Each operation is tracked into a MySQL data base which interfaces the TMPPS pipeline to the rest of the scientific pipeline running at ADC. In this paper the architecture and the performance of the TMPPS will be described and discussed.

The Medium-Energy Gamma-ray Astronomy library MEGAlib is an open-source object-oriented software library designed to simulate and analyze data of low-to-medium-energy gamma-ray telescopes, especially Compton telescopes. The library comprises all necessary simulation and data analysis tools including geometry construction, Monte-Carlo simulation, response creation, event reconstruction, image reconstruction, and other high-level data-analysis tools.

The importance of hard X-ray astronomy (>10 keV) is now widely recognized. Recently both ESA and NASA have indicated in their guidelines for the progress of X- and γ-ray astronomy in the next decade the development of new instrumentation working in the energy range from the keV to the MeV region, where important scientific issues are still open, exploiting high sensitivity for spectroscopic imaging and polarimetry observations. The development of new concentrating (e.g. multilayer mirror) telescopes for hard X-rays (10 -100 keV) and focusing instruments based on Laue lenses operating from ~60 keV up to a few MeV is particularly challenging. We describe the design of a threedimensional (3D) depth-sensing position sensitive device suitable for use as the basic unit of a high efficiency focal plane detector for a Laue lens telescope. The sensitive unit is a drift strip detector based on a CZT crystal, (10×10 mm² area, 2.5 mm thick), irradiated transversally to the electric field direction. The anode is segmented into 4 detection cells, each comprising one collecting strip and 8 drift strips. The drift strips are biased by a voltage divider, whereas the anode strips are held at 0 V. The cathode is divided in 4 horizontal strips for the reconstruction of the Z interaction position. The 3D prototype will be made by packing 8 linear modules, each composed of 2 basic sensitive units, bonded onto a ceramic layer together with the readout electronics.

We present preliminary results for the calibration and flight performance of the Long-Slit Imaging Dual Order Spectrograph (LIDOS), a rocket-borne instrument with a large dynamic range in the 900 - 1650 Å bandpass. The instrument observes UV-bright objects with a CCD channel and fainter nebulosity with an MCP detector. The image quality and the detector quantum efficiencies were determined using the calibration and test equipment at the Johns Hopkins University, and further monitored using an on-board electron-impact calibration lamp. We review results from each of the three flights of the instrument.

We have designed a sounding rocket payload to perform high resolution far ultraviolet (FUV) spectroscopy. The payload will contain a modified Rowland spectrograph, achieving resolution (λ/δ λ) of 60,000 by adding a magnifying secondary optic. We will use this instrument to observe two stars on opposing sides of the Local Bubble wall. Obtaining spectra of the O VI doublet in absorption towards these stars will provide new insight into the processes governing hot gas near the cavity wall.

The High-resolution Lightweight Telescope for the EUV (HiLiTE) is a Cassegrain telescope that will be made entirely of Silicon Carbide (SiC), optical substrates and metering structure alike. Using multilayer coatings, this instrument will be tuned to operate at the 465 Å Ne VII emission line, formed in solar transition region plasma at ~500,000 K. HiLiTE will have an aperture of 30 cm, angular resolution of ~0.2 arc seconds and operate at a cadence of ~5 seconds or less, having a mass that is about 1/4 that of one of the 20 cm aperture telescopes on the Atmospheric Imaging Assembly (AIA) instrument aboard NASA's Solar Dynamics Observatory (SDO). This new instrument technology thus serves as a path finder to a post-AIA, Explorer-class missions.

We report accelerated aging tests on three Pt/Ne lamps from the same manufacturing run as lamps installed on the Cosmic Origins Spectrograph (COS). Initial radiometrically calibrated spectra were taken for each lamp at the National Institute of Standards and Technology (NIST). One lamp was aged in air at NIST at a current of 10 mA and 50% duty cycle (30 s on, 30 s off) until failure. Calibrated spectra were taken after 206 h, 500 h, 778 h, 783 h and 897 h of operation. Two other lamps were aged by the COS instrument development team in a thermal vacuum chamber, with calibrated spectra taken at NIST after 500 h of operation. In all three lamps, total output dropped by less than 15 % over 500 h. We conclude that the lamps will satisfy the requirements of COS in both lifetime and spectral stability.

We report accelerated vacuum aging tests on two Pt-Ne lamps identical and/or similar to those installed on the Cosmic Origins Spectrograph (COS) to be installed in the Hubble Space Telescope (HST) in the fall of 2008. One additional lamp was aged in air at the National Institute of Standards and Technology (NIST). All lamps were tested at a 50% duty cycle (30 s on/off) at flight nominal (10 mA) constant current until failure. Calibrated spectra of all lamps were taken at NIST using the 10.7-m normal incidence vacuum spectrograph at various points in the life of the lamps. In this paper we report the results of the photometric, electrical, and thermal monitoring of the vacuum tested lamps, while the spectroscopic and air aging results are given in a companion paper (Nave et al., 2008, SPIE 7011-134). We conclude that the lamps will satisfy the requirements of the HST/COS mission in terms of lifetime, cycles, and thermal and spectral stability.

We present deep scatter measurements on a sinusoidal profile, high groove density, holographically ruled, large format grating. With long exposures and a low-noise detector, we were able to measure scatter at levels of 1 * 10^-6/Ly α/nm at 100 nm. The result has potential impacts in the prospect of high sensitivity measurements of very faint objects at FUV wavelengths. Any instrument sensitive to hydrogen Lyman α, a bright geo-coronal airglow line, must control the scatter to make astrophysically significant measurements. Measurements of very faint emission line source - particularly ones that do not have known redshifts (i.e. wavelength solution), Lyman α scatter may be the dominant source of error. Therefore, characterization of the actual value of scatter is crucial to the success of future missions that will use diffraction-based measures for detecting very faint targets.

Multiplexed readout of TES (Transition Edge Sensor) signals is one of the key technologies needed to realize large format arrays of microcalorimeters in future X-ray missions. In the FDM (Frequency-Domain Multiplexing) approach using MHz biasing frequencies, a wide band-width FLL (Flux Locked Loop) circuit is essential to compensate the phase delay between the TES sensor and the room temperature circuits. An analog feedback circuit using a lock-in amplifier technique and phase shifters with a very low noise pre-amplifier is being developed. This circuit will be tested with an actual TES array and an 8-input SQUID in the EURECA project.

The SXS (Soft X-ray Spectrometer) onboard the coming Japanese X-ray satellite NeXT (New Exploration Xray Telescope) and the SXC (Spectrum-RG X-ray Calorimeter) in Spectrum-RG mission are microcalorimeter array spectrometers which will achieve high spectral resolution of ~ 6 eV in 0.3-10.0 keV energy band. These spectrometers are well-suited to address key problems in high-energy astrophysics. To achieve these high spectral sensitivities, these detectors require to be operated under 50 mK by using very efficient cooling systems including adiabatic demagnetization refrigerator (ADR). For both missions, we propose a two-stage series ADR as a cooling system below 1 K, in which two units of ADR consists of magnetic cooling material, a superconducting magnet, and a heat switch are operated step by step. Three designs of the ADR are proposed for SXS/SXC. In all three designs, ADR can attain the required hold time of 23 hours at 50 mK and cooling power of 0.4μW with a low magnetic fields (1.5/1.5 Tesla or 2.0/3.0 Tesla) in a small configuration (180 mmφ× 319 mm in length). We also fabricated a new portable refrigerator for a technology investigation of two-stage ADR. Two units of ADR have been installed at the bottom of liquid He tank. By using this dewar, important technologies such as an operation of two-stage cooling cycle, tight temperature control less than 1 μK (in rms) stability, a magnetic shielding, saltpills, and gas-gap heat switches are evaluated.

LMSAL and NIST are developing position-sensitive x-ray strip detectors based on Transition Edge Sensor (TES) microcalorimeters optimized for solar physics. By combining high spectral (E/ΔE ~1600) and temporal (single photon Δt ~10μs) resolutions with imaging capabilities, these devices will be able to study high-temperature (>10 MK) x-ray lines as never before. Diagnostics from these lines should provide significant new insight into the physics of both microflares and the early stages of flares. Previously, the large size of traditional TESs, along with the heat loads associated with wiring large arrays, presented obstacles to using these cryogenic detectors for solar missions. Implementing strip detector technology at small scales, however, addresses both issues: here, a line of substantially smaller effective pixels requires only two TESs, decreasing both the total array size and the wiring requirements for the same spatial resolution. Early results show energy resolutions of Δ Ε_FWHM ~30eV and spatial resolutions of ~10-15 μm, suggesting the strip-detector concept is viable.

The Micro-X High Resolution Microcalorimeter X-ray Imaging Rocket is sounding rocket experiment that will combine a transition-edge-sensor X-ray-microcalorimeter array with a conical imaging mirror to obtain high-spectral-resolution images of extended and point X-ray sources. Our first target is the Puppis A supernova remnant, which will be observed in January 2011. The Micro-X observation of the bright eastern knot of Puppis A will obtain a line-dominated spectrum with up to 90,000 counts collected in 300 seconds at 2 eV resolution across the 0.3-2.5 keV band. Micro-X will utilize plasma diagnostics to determine the thermodynamic and ionization state of the plasma, to search for line shifts and broadening associated with dynamical processes, and seek evidence of ejecta enhancement. We describe the progress made in developing this payload, including the detector, cryogenics, and electronics assemblies. A detailed modeling effort has been undertaken to design a rocket-bourne adiabatic demagnetization refrigerator with sufficient magnetic shielding to allow stable operation of transition edge sensors, and the associated rocket electronics have been prototyped and tested.

Fine-pitch and thick-foil GEMs have been produced using a laser etching technique for photoelectric X-ray polarimeters onboard future missions. The finest hole pitch of the thick-foil GEM is 80 μm with a hole diameter of 40 μm, and a thickness of the insulator is 100 µm. The maximum effective gain in a 70%-30% mixture of argon and carbon dioxide reaches 3×10⁴ at voltage of 750 V between GEM electrodes. No significant gain increase or decrease was observed during 24 hours test in which applied high voltage was ramped up and down frequently. The measured gain stability was less than 4%. An accelerated test of the high voltage ramp up and down for two years LEO operations were carried out. During the 6500 times voltage ramp up and down, the GEM kept its gain within 4% variation and no unexpected behavior was observed.

We have developed the gas electron multiplier (GEM) for applying to a cosmic X-ray polarimeter. For a space use of the GEM, we performed experiments of charged particles irradiation to the GEM as space environmental tests of cosmic rays. The GEM is irradiated with full-striped iron ions with energy of 500 MeV/n, as a result, we found that even if a particle deposits an energy of ~ 2 MeV in the detector, it has no direct effect on the GEM as long as the particle does not hit the GEM directly. In contrast, every time a particle collides with the GEM, it discharges with a probability of 0.4-40% which depending on the count rate, the applied voltage, and energy losses, but the mass of particles does not matter. The predicted count rate of discharges in the space is low enough, so it is negligible compared with a target object. We also found that an irradiation of charged particles for a certain period causes a destruction of the GEM, but the direct reason remains unclear.

We studied how the configuration parameters of a CCD (pixel size and depletion layer thickness) affect the instrumental background of an X-ray CCD camera in the space environment through the Monte-Carlo simulation. X-ray detectors are in general sensitive not only to X-rays but also to charged particles. The latter produce pseudo-signal indistinguishable from that of X-rays, which is called instrumental background. It is essential to reduce the instrumental background for the observations of dim and diffuse X-ray sources, but the low background was not considered as a design goal of an X-ray CCD camera so far. We utilized the Monte-Carlo simulator, which could successfully reproduce the Suzaku XIS background, for the current analysis. We found that thicker depletion layer tends to increase the background except for the >5 keV band of the backside-illuminated CCD. On the other hand, pixel-size dependence was different between the frontside and backside illuminated CCDs. These results are interpreted in terms of the interaction of cosmic/X-rays with the CCD.

eROSITA (extended ROentgen Survey with an Imaging Telescope Array) is the core instrument of the Russian SRG satellite which will be launched in 2011 into an orbit of 600 km height and 30° inclination. It is being developed by the Max-Planck-Institute fur extraterrestrische Physik (MPE) in Garching, Germany. It comprises seven nested Wolter-I grazing incidence telescopes, each equipped with its own CCD camera. The seven eROSITA CCD cameras require a stable operating temperature of about (-80±0,5)°C. Therefore the thermal control system is vitally important. The cooling system consists of passive thermal control components only: two radiators, variable conductance heat pipes (VCHP) and two special thermal storage units. By reason of the low-earth-orbit and the special scan geometry it is impossible for one radiator to look into the cold space at all times. The cameras and the radiators are connected by variable conductance heat pipes which can be cut off when a radiator gets too warm. A novel "latent cold storage unit" guarantees an absolute constant temperature without any further control mechanism.

Future generations of X-ray astronomy instruments will require position sensitive detectors in the form of charge-coupled devices (CCDs) for X-ray spectroscopy and imaging with the ability to probe the X-ray universe with greater efficiency. This will require the development of CCDs with structures that will improve their quantum efficiency over the current state of the art. The quantum efficiency improvements would have to span a broad energy range (0.2 keV to >15 keV). These devices will also have to be designed to withstand the harsh radiation environments associated with orbits that extend beyond the Earth's magnetosphere. This study outlines the most recent work carried out at the University of Leicester focused on improving the quantum efficiency of an X-ray sensitive CCD through direct manipulation of the device depletion region. It is also shown that increased spectral resolution is achieved using this method due to a decrease in the number of multi-pixel events. A Monte Carlo and analytical models of the CCD have been developed and used to determine the depletion depths achieved through variation of the device substrate voltage, Vss. The models are also used to investigate multi-pixel event distributions and quantum efficiency as a function of depletion depth.