Determination of the shape of very thin x-ray mirrors employed in spaced-based telescopes continues to be challenging.
The mirrors' shapes are not readily deduced to the required accuracy because the mount induced distortions are often
larger than the uncertainty tolerable for the mission metrology. In addition to static deformations, dynamic and thermal
considerations are exacerbated for this class of mirrors. We report on the performance of one temporary mounting
scheme for the thin glass mirrors for the Constellation-X mission and prospects for deducing their undistorted shapes.
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 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.
As NASA's next major x-ray astronomical mission following the James Webb Space Telescope,
Constellation-X requires technology advances in several areas, including x-ray optics, x-ray detectors,
and x-ray gratings. In the area of x-ray optics, the technology challenge is in meeting a combination of
angular resolution, effective area, mass, and production cost requirements. A vigorous x-ray optics
development program has been underway to meet this challenge. Significant progress has been made in
mirror fabrication, mirror mount and metrology, and mirror alignment and integration. In this paper we
give a brief overview of our development strategy, technical approaches, current status, and expectations
for the near future and refer interested readers to papers with an in-depth coverage of similar areas.
We present an overview update of the metrologic approach to be employed for the segmented mirror fabrication for
Constellation-X spectroscopy x-ray telescope. We compare results achieved to date with mission requirements. This is
discussed in terms of inherent capability versus in-practice capability. We find that all the needed metrics for the mirrors
are in hand but that they are currently limited by the mounting of the mirrors themselves.
We present the concepts behind the current alignment and integration technique for a Constellation-X primary-secondary
mirror segment pair prior to an x-ray beam line test. We examine the effects of a passive mount on thin glass x-ray mirror
segments, and the issues of mount shape and environment on alignment. We also investigate how bonding and transfer to a
permanent housing affects the quality of the final image.
One of the most important aspects of the Constellation-X x-ray optics development is the fabrication of
lightweight mirror segments. Given its multi-faceted requirements, i.e., good angular resolution, light
weight, and low production cost, we have adopted a glass slumping or forming technique that takes
advantage of the naturally excellent microroughness of thin float glass sheets. In this paper we present
measured quantities of formed mirror segments and compare them with requirements to show that the
formed mirror segments have met all except the sag requirement. The larger than acceptable sag error
may be an artifact of the measurement process. It may also be caused by coating stress or residual thermal
stress resulting from the slumping process. Our immediate future task is to identify the source(s) of the
sag error and address them accordingly.
A single Constellation-X Spectroscopy X-ray Telescope (SXT) mirror segment pair is being aligned in the Optical
Alignment Pathfinder 2 (OAP2) platform using a combination of mechanical and optical techniques. Coarse positioning
was provided through a contact probe, the alignment was refined in a collimated while-light facility used for the Suzaku
(ASTRO-E2) satellite, and then finalized with a combination of a Centroid Detector Assembly (CDA) and an
interferometer coupled to a novel conical null lens providing surface map imaging over 60% of the mirror surface at one
time. Due to a variety of reasons, the positioning and figure of the mirror segment under examination can shift, and we
test how reliably high quality alignment can be reproduced on any given day. Also, the mirror segment's deformation
response to deliberate misalignments has been tested, providing a response matrix for these thin glass mirror segments.
We describe recent progress in the technology development program for the mirror system for the Constellation-X Spectroscopy X-ray Telescope (SXT). Development of this mirror represents a significant technology challenge, as it must provide a combination of large effective area (3 sq. m) and modest angular resolution (15 arc second half power diameter requirement; 5 arc second goal) with a limited mass allocation. The baseline design incorporates over 200 nested Wolter 1 mirrors. Each of these in turn is segmented in order to simplify handling of the mirrors and facilitate mass production. The X-ray reflecting surfaces are fabricated from thin, thermally formed glass sheets. Production improvements have yielded mirror segments that approach the performance requirement without the need for epoxy replication. A mounting and alignment approach incorporating piezoelectric actuators has been shown to manipulate mirror segments with the required precision without introducing significant distortion. Substantial improvements in metrology methodology have provided insights into the mirror segment forming and alignment processes. We describe the technical advances made over the past year and summarize near-term plans.
The Multi-order Solar EUV Spectrograph (MOSES) is a slitless spectrograph designed to study solar He II emission at 303.8 Å (1 Å = 0.1 nm), to be launched on a sounding rocket payload. One difference between MOSES and other slitless spectrographs is that the images are recorded simultaneously at three spectral orders, m = -1, 0, +1. Another is the addition of a narrow-band multilayer coating on both the grating and the fold flat, which will reject out-of-band lines that normally contaminate the image of a slitless instrument. The primary metrics for the coating were high peak reflectivity and suppression of Fe XV and XVI emission lines at 284 Å and 335 Å, respectively. We chose B4C/Mg2Si for our material combination since it provides excellent peak reflectivity and rejection of out-of-band wavelengths. Measurements of witness flats at NIST indicate the peak reflectivity at 303.8 is 39.0% for a 15 bilayer stack, while suppression ranges from 7.5x to 12.9x at 284 Å and from 3.4x to 15.1x at 335 Å for the individual reflections in the optical path. We present the results of coating the MOSES flight gratings and fold flat, including the spectral response of the fold flat and grating as measured at NIST's SURF III and Brookhaven's X24C beamline, respectively.
The Constellation-X Spectroscopy X-ray Telescope (SXT) is a large diameter, high throughput, grazing incidence imaging mirror system, designed to perform high sensitivity spectroscopy of cosmic X-ray sources in the 0.2-10.0 keV band. The baseline effective area requirement is ~3 m2 at 1 keV. The system-level angular-resolution requirement is a 15-arcseconds half-power diameter, with a 5-arcsecond goal. The effective area is attained through a modular design, involving the nesting of many confocal, thin-walled Wolter I mirror segments. Considerable progress has been made in developing thin, thermally formed, glass mirror substrates that meet or better the angular-resolution requirement. Several approaches to mounting and aligning reflector segments into a mirror system are under investigation. We report here on the progress of the SXT technology development program toward reaching the performance goals.
As technological and scientific path-finder towards future observatory missions, a balloon-born hard X-ray imaging observation experiment InFOCμS has been developed. The payload has flown four times since 2000. In its 2004 Fall flight campaign InFOCμS successfully achieved first scientific observations of multiple astronomical objects from galactic compacts to cluster of galaxies. Significant signal has been detected from bright galactic objects while analysis of extragalactic objects is underway. InFOCμS plans additional and upgraded telescope-detector system as early as 2006. High energy telescope for nuclear gamma-ray line observations is under planning.
We have tested the operation and spectral coverage of two different types of EUV light sources for EUV characterization of astronomical mirror coatings, gratings, filters and detectors. Based on successes reported by another group investigating EUV-range K and L shell emission, we tested the feasibility of using Bremmstrahlung emission from a standard x-ray tube with the beryllium window removed. The second source is a Penning gas discharge source reported previously. The range of characterization and combinations of cathode and gas materials has been extended. Using the C/Ne and C/CO2 combinations provides nearly full coverage of the 200-600 Å spectral range with a high density of spectra lines. Use of carbon cathodes as opposed to the standard aluminum or magnesium cathodes allows one to operate the source for a long period of time before having to break vacuum and replace the disposable cathodes.
The status of technology development for the Constellation-X Spectroscopy X-ray Telescope (SXT) mirror is presented. The SXT mirror combines a large (1.6 m) aperture with modest (12 arc sec half power diameter) angular resolution and low mass (750 kg). The overall collecting area, larger than 9,600 square cm at 0.25 keV, requires high throughput, and thus nesting of a substantial number of thin reflectors. A phased development program is underway to develop reflectors, mounting and alignment approaches, and metrology techniques for components and the mirror has a whole. The latest results in all these areas are summarized, along with an overview of results of optical testing of reflector performance.
Hard X-ray focusing observation is important to reveal non-thermal
emission mechanism and origin in active galaxies and clusters of
galaxies. We have carried out the hard X-ray observation throughout
the ¥infocus program, which is an international balloon-borne
experiment in collaboration with NASA/GSFC and Nagoya University.
The telescope is conical approximation of Wolter-I optics with 8 m
focal length and 40 cm diameter. It consists of 255 nested thin (0.17
mm thickness) reflectors with incidence angles of 0.10° to
0.36°. Reflectors are coated with depth-graded platinum-carbon (Pt/C) multilayers, so-called supermirrors, with periodic length of 2.6 to 13 nm and bi-layer number of 28 to 79, depending on incidence angles. We are now continuously fabricating advanced next hard X-ray telescope for the second ¥infocus flight in 2004. Compared with the first telescope, the following improvements have been made on the second one. Supermirror reflectors have wider sensitivity in energy band of 20-60 keV adopting optimum supermirror design for balloon
observation, and smaller interfacial roughness owing to complete
replication technique. For upgrading of the image quality, we then
adopted stiffer reflector substrate, selected replication mandrel with
better shape, and the modified telescope housing with higher alignment
accuracy for reflectors. The performance of the new hard X-ray
telescope was measured in X-ray beamline facility in ISAS/JAXA and
synchrotron radiation facility SPring-8. The effective area and image
quality are obtained to be 45 cm2 at 30 keV and 23 cm2 at 40 keV, and 2.5 arcmin in half power diameter, respectively. In this paper we report our development of the upgraded hard X-ray telescope for the second balloon flight experiment.
The Constellation-X SXT mirrors and housings continue to evolve toward a flight-like design. Our second-generation alignment housing, the Optical Alignment Pathfinder 2 (OAP2), is a monolithic titanium structure that is nested inside the OAP1 alignment jig, described in a previous paper (J. Hair, et. al., SPIE 2002). In order to perform x-ray tests in a configuration where the optical axis is horizontal, and continue to develop more flight-like structures, we needed to design a strong, but lightweight housing that would impart minimal deformations on the thin segmented mirrors when it is rotated from the vertical orientation used for optical alignment to the horizontal orientation that is used for x-ray testing. This paper will focus on the design of the OAP2 housing, and the assembly and alignment of the optics within the OAP1 plus OAP2 combination using the Centroid Detector Assembly (CDA). The CDA is an optical alignment tool that was successfully used for the HRMA alignment on the Chandra X-ray Observatory. In addition, since the glass we are using is so thin and flexible, we will present the response of the optical alignment quality of a Wolter-I segment to known deformations introduced in by the OAP1 alignment housing.
The Constellation-X mission is a follow-on to the current Chandra and XMM missions. It will place in orbit an array of four X-ray telescopes that will work in unison, having a substantial increase in effective area, energy resolution, and energy bandpass over current missions. To accomplish these ambitious increases new optics technologies must be exploited. The primary instrument for the mission is the Spectroscopy X-Ray Telescope (SXT), which covers the 0.21 to 10 keV band with a combination of two x-ray detectors: a reflection grating spectrometer with CCD readout and a micro-calorimeter. Mission requirements are an effective area of 15,000 cm2 near 1 keV and a 15 arc-sec (HPD) image resolution with a goal of 5 arc-sec. The Constellation-X SXT uses a segmented design with lightweight replicated optics. A technology development program is being pursued with the intent of demonstrating technical readiness prior to the program new start. Key elements of the program include the replication of the optical elements, assembly and alignment of the optics into a complete mirror assembly and demonstration of production techniques needed for fabrication of multiple units. These elements will be demonstrated in a series of engineering development and prototype optical assemblies which are increasingly flight-like. In this paper we present an image angular resolution error budgets for the SXT and for the Optical Assembly Pathfinder #2 (OAP2), the first of engineering development units intended to be tested in x-rays. We describe OAP2 image error sources and performance analyses made to assess error sensitivities. Finally we present an overall prediction of as-tested imaging performance in the x-ray test facility.
The Constellation X-ray Observatory consists of four identical spacecraft, each carrying a complement of high sensitivity X-ray instrumentation. At the heart of each is the grazing incidence mirror of the Spectroscopy X-ray Telescope (SXT). This mirror has a diameter of 1.6 m, a focal length of 10 m, mass not exceeding ~650 kg. The required angular resolution is 15 arc seconds and the effective area at 1 keV must exceed 7,500 cm2. Achieving these performance requirements in a cost effective way within the allocated mass is accomplished via a modular design, incorporating lightweight, multiply-nested, segmented Wolter Type I X-ray mirrors. The reflecting elements are composed of thin, thermally formed glass sheets, with epoxy-replicated X-ray reflecting surfaces. Co-alignment of groups of reflectors to the required sub-micron accuracy is assisted by precision silicon microstructures. Optical alignment incorporates the Centroid Detector Assembly (CDA) originally developed for aligning the Chandra mirror. In this talk we present an overview of recent progress in the SXT technology development program. Recent efforts have concentrated on producing an engineering unit that demonstrates all the key fabrication and alignment processes, and meets the angular resolution performance goal. Additionally, we describe the initial steps toward flight mirror production, anticipating a Constellation-X launch early in the next decade.
As NASA’s next facility-class x-ray mission, Constellation X will provide high-throughput, high-resolution spectroscopy for addressing fundamental astrophysical and cosmological questions. Key to the Constellation-X mission is the development of lightweight grazing-incidence optics for its Spectroscopy X-ray Telescopes (SXT) and for its Hard X-ray Telescopes (HXT). In preparation for x-ray testing Constellation-X SXT and HXT development and demonstration optics, Marshall Space Flight Center (MSFC) is upgrading its 100-m x-ray test facility, including development of a five degree-of-freedom (5-DoF) mount for translating and tilting test articles within the facility’s large vacuum chamber. To support development of alignment and assembly procedures for lightweight x-ray optics, Goddard Space Flight Center (GSFC) has prepared the Optical Alignment Pathfinder Two (OAP2), which will serve as a surrogate optic for developing and rehearsing x-ray test procedures. In order to minimize thermal distortion of the mirrors during x-ray testing, the Harvard-Smithsonian Center for Astrophysics (CfA) has designed and implemented a thermal control and monitoring system for the OAP2. CfA has also built an aperture wheel for masking and sub-aperture sampling of the OAP2 to aid in characterizing x-ray performance of test optics.
The development of hard X-ray focusing optics is widely recognized as
one of key technologies for future X-ray observatory missions such as
NeXT(Japan), Constellation-X(US) and possibly XEUS(Europe). We have developed hard X-ray telescope employing depth-graded multilayers, so-called supermirrors. Its benefit is to reflect hard X-rays by Bragg reflection at incidence angles larger than the critical angle of total external reflection. We are now continuously fabricating platinum-carbon(Pt/C) supermirror reflectors for hard X-ray observations. In this paper we focus on our development of the
hard X-ray telescope for the first balloon flight observation
(InFOCuS) and its results. InFOCuS is an international balloon-borne hard X-ray observation experiment initiated by NASA/GSFC. InFOCuS hard X-ray telescope have been jointly developed by Nagoya University and GSFC. The telescope is conical approximation of Wolter-I optics with 8m focal length and 40cm diameter. It consists of 255 nested ultra-thin reflector pairs with incidence angles of 0.10 to 0.36deg. Reflectors are coated with Pt/C supermirrors with periodic length of 2.9 to 10nm and bi-layer number of 25 to 60, depending on incidence angles. The effective area and imaging quality are expected as 100 cm2 at 30 keV and 2 arcmin in half power diameter, respectively. The InFOCuS experiment was launched on July 5, 2001, from National Scientific Balloon Facility in Texas, USA. We successfully observed Cyg X-1, chosen for a calibration target, in 20-40keV energy band. We are planning to carry out next flight for scientific observations as soon as additional telescopes, detectors, and upgraded gondola system are implemented.
As NASA's next major x-ray observatory, Constellation-X will have a photon collection area of 30,000 cm2 at 1 keV, which, after folding other instrumental respojnses, translates into an effective aera of 15,000 cm2. The observatory consists of four identical satellites each of which carries a spectroscopic x-ray telescope mirror assembly (SXT) that is 1.6 m in diameter and has a focal length of 10 m and a collection area of 7,500 cm2 at 1 keV and an angular resolution of 15" HPD at the system level. Each mirror assembly consists of a large number of mirror segments precisely assembled together. Our development of the mirror segments is divided into two steps. The first one is to develop the basic approach and fabricate segments within the constraints of existing infra-structure to meet the angular resolution requirement, but not mirror segments precisely assembled together. Our development of the mirror segments is divided into two steps. The first one is to develop the basic approach and fabricate segments within the constraints of existing infra-structure to meet the angular resolution requirement, but not mirror segment size requirement. We have all but successfully competed this part of the development. We are now on the verge of going into the second step, that is to fabricate mirror segments of larger sizes to reduce the number of segments that have to be aligned and integrated. In this paper, we report on the requirements and the development status of the mirror segments. These assembly and other requirements of the SXT are reported elsewhere.
We have been developing the high throughput hard X-ray telescope, using reflectors coated with the depth graded multilayer known as supermirror, which is considered to be a key technology for future satellite hard X-ray imaging missions. InFOC(mu) $S, the International Focusing Optics Collaboration for (mu) -Crab Sensitivity is the project of the balloon observation of a cosmic hard X-ray source with this type of hard X-ray telescope and CdZnTe pixel detector as a focal plane imager. For the fist InFOC(mu) S balloon experiment, we developed the hard X-ray telescope with outermost diameter of 40cm, focal length of 8m and energy band pass of 20-40 keV, for which Pt/C multilayer was used. From the pre-flight X-ray calibration, we confirmed its energy band and imaging capability of 2 arcmin HPD and 10 arcmin FOV of FWHM, and a effective area of 50 cm2 for 20-40 keV X-ray. We report the current status of our balloon borne experiment and performance of our hard X-ray telescope.
Mass production of replicated thin aluminum x-ray reflecting foils for the InFOC(mu) S (International Focusing Optics Collaboration for Micro-Crab Sensitivity) balloon payload is complete, and the full mirror has been assembled. InFOC(mu) S is an 8-meter focal length hard x-ray telescope scheduled for first launch in July 2001 and will be the first instrument to focus and image x-rays at high energies (20-40 keV) using multilayer-based reflectors. The individual reflecting elements are replicated thin aluminum foils, in a conical approximation Wolter-I system similar to those built for ASCA and ASTRO-E. These previous imaging systems achieved half-power-diameters of 3.5 and 1.7-2.1 arcminutes respectively. The InFOC(mu) S mirror is expected to have angular resolution similar to the ASTRO-E mirror. The reflecting foils for InFOC(mu) S, however, utilize a vertically graded Pt/C multilayer to provide broad-band high-energy focusing. We present the results of our pre-flight characterization of the full mirror, including imaging and sensitivity evaluations. If possible, we will include imaging results from the first flight of a multilayer-based high-energy focusing telescope.
Spatially extended quasi-monoenergetic x-ray beams will allow improved performance for many applications in diagnostic radiology. X-rays with well-defined energies between 15 keV and 20 keV can be used to enhance the contrast of mammography images while reducing dose to the patient. Diagnostic radiology using iodine, xenon, or barium as a contrast agent can be made more sensitive by using nearly monoenergetic x-rays with energies just above and below their K edges near 33 keV, 34 keV, and 37 keV. We describe the design and preliminary performance measurements of a prototype thin film multilayer x-ray narrow-band filter or monochromator designed to produce fan-shaped beams of x-rays at 33 keV. A set of closely spaced thin foil substrates coated with graded Pt/C multilayers provides energy selectivity when illuminated by a diverging broad-band x-ray beam incident on the foils at near-grazing angles from 0.2 degrees to 0.3 degrees. The individual thin foil mirrors are mounted into top and bottom precision alignment structures formed by deep reactive ion etching 1-mm thick silicon wafers.
The ability of periodic and aperiodic multilayer structures to diffract x-rays at grazing angles has long been understood, and has been successfully exploited in the x-ray region, primarily on flat substrates. We have recently begun producing Pt/C multilayer coated thin foil mirrors for the InFOC(mu) S balloon mission. The mirrors are made by depositing the multilayer on glass mandrels and transferring the multilayer to the thin foil substrates using a replication process similar to that used for production of the recently lost ASTRO-E mirrors. Both periodic and broadband versions have been successfully replicated onto thin foils and characterized by grazing incidence x-ray scattering. Initial comparisons between mirrors deposited on flat float glass substrates and mirrors replicated onto thin foils indicate that the reflection properties of the multilayer are not damaged by the transfer from mandrel to foil. We describe the production and characterization facilities that have been developed in our lab, and the performance of our multilayer mirrors, with particular emphasis on the characterization of interfaces in the Pt/C system.
High sensitivity hard X-ray data by means of focusing optics is crucially important to investigate active galaxies and cluster of galaxies. We have developed focusing telescopes with platinum-carbon multilayer coatings. The energy band is broadened by multilayers with graded periodic length, so called `Supermirrors'. We were successful to obtain hard X- ray images in the energy band from 25 to 40 keV with a demonstration model of telescope with 20 mirror shells of supermirrors. The flight model of supermirror telescope is now in production for balloon flight in the summer of 2000. The current status of the balloon mission and future application of supermirror technology is discussed.
Measurements have been performed on a prototype CdZnTe linear array designed for direct digital mammography. Direct detection of x-ray photons without conversion to visible light avoids the trade-off between resolution and efficiency with phosphor thickness inherent in the conversion process. Polycapillary x-ray optics can be used to shape the x-ray image in a manner similar to the use of fused fiber optic tapers with visible light. The polycapillary optics also provide significant scatter rejection and resultant contrast enhancement. The theoretical detector quantum efficiency of CdZnTe at mammographic energies (20 keV) is quite high. Measurements were performed of DQE values and uniformity from 13 - 256 keV in large single pixel detectors. Uniformity and imaging measurements were also performed on a prototype 1 cm long linear detector array with 50 micrometer pixels attached to read-out electronics using indium bump bonding technology.
Polycapillary x-ray optics have found potential application in many different fields, including antiscatter and magnification in mammography, radiography, x-ray fluorescence, x-ray lithography, and x-ray diffraction techniques. In x-ray diffraction, an optic is used to collect divergent x-rays from a point source and redirect them into a quasi-parallel, or slightly focused beam. Monolithic polycapillary optics have been developed recently for macromolecular crystallography and have already shown considerable gains in diffracted beam intensity over pinhole collimation. Development is being pursued through a series of simulations and prototype optics. Many improvements have been made over the stage I prototype reported previously, which include better control over the manufacturing process, reducing the diameter of the output beam, and addition of a slight focusing at the output of the optic to further increase x-ray flux at the sample. We report the characteristics and performance of the stage I and stage II optics.
Bimal Rath, D. Aloisi, Donald Bilderback, Ning Gao, Walter Gibson, F. Hofmann, B. Homan, Chris Jezewski, Ira Klotzko, J. Mitchell, Scott Owens, Johannes Ullrich, Lei Wang, Gregory Wells, Qi-Fan Xiao, Carolyn MacDonald
Several applications of Kumakhov polycapillary optics require extended exposure to intense x- ray radiation. No degradation of performance has been observed when using polycapillary x- ray optics with laboratory sources. As part of an ongoing study to develop an understanding of damage mechanisms and performance limitations, borosilicate glass polycapillaries have been exposed to white beam bending magnet synchrotron radiation with peak energies of 5 and 11 keV, and focused broad band energy centered at 1.4 keV synchrotron radiation. In situ and ex situ measurements of degradation of x-ray transport efficiency have been performed at doses up to 1.8 MJ/cm2 at ambient and elevated temperatures. No decrease in transmission was observed for in situ measurement of fibers exposed to 1.4 keV photons at doses up to 1.4 MJ/cm2. Ambient temperature exposure to higher photon energies causes degradation that can be recovered by low temperature annealing. Exposure at elevated temperatures prevented any measurable damage to rigid fibers, at doses up to 800 kj/cm2.
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