A triple axis X-ray diffractometer, designed and built at the Danish Space Research Institute, was used to make a high resolution study of the performance of a 2000 angstroms period, high energy X-ray transmission grating developed at MIT for one of the grating spectrometers on the Advanced X-ray Astrophysics Facility. Data was obtained at CuK_(alpha )₁ (8.048 keV) and, using single reflection asymmetric Si(044) crystals for both the monochromator and analyzer, an angular resolution of 1.5 arcsec FWHM was achieved. The efficiency of the grating in all orders up to the 15th was measured using a 12 kW rotating anode X-ray generator. These data provided the basis for a modelling of the grating structure.

The Advanced X-ray Astrophysics Facility--Imaging is one of two complementary space-based x-ray observatories being developed by NASA. Utilizing grazing incidence mirror elements in a Wolter Type I configuration, it will image x-ray sources over an energy range of 0.1 to 10 KeV. This paper describes the deposition of iridium/chromium coatings on Zerodur substrates using DC magnetron sputtering for use in grazing incidence configuration. Included are a description of the configuration and parameters of the deposition process, the results of x-ray performance measurements, and the implications of the results for scaling the deposition process to the full scale AXAF-I mirror elements.

This analysis of the extreme ultraviolet (EUV) performance of Wolter type II telescopes as degraded by state-of-the-art optical fabrication errors is motivated by NASA's upcoming Far Ultraviolet Spectroscopic Explorer (FUSE) mission. The primary goal of the FUSE mission is to perform high resolution spectroscopy in the spectral range of 912 angstroms - 1200 angstroms. The optical performance of the FUSE telescope will degrade drastically toward the EUV and of the spectrum. This image degradation is caused by the scattering effects of residual surface irregularities inherent in the optical fabrication process. NASA's Optical Surface Analysis Code is used to parametrically model the image degradation due to optical fabrication errors over the entire range of relevant spatial frequencies and allows us to determine the optical fabrication tolerances necessary to achieve improved performance in the EUV.

The S-056 Wolter I soft x-ray mirror used originally on Skylab for x-ray observations of the Sun is still in use today. The mirror has been flow polished to a surface finish of 5 angstroms for spatial frequencies from 1 - 1000 mm^-1 and has been tested in the AXAF x- ray calibration facility located at Marshall Space Flight Center, Alabama. The mirror performance was enhanced by a new polishing technique and was found to have an experimental point spread function full width half maximum of less than 1 arc second at 8.3 angstroms. No change in the figure was observed.

This paper describes and illustrates simple expressions for determining the effects of conventional and fractal surface errors on the performance of a simple imaging system, and conversely, of specifying surface-finish parameters in terms of system performance requirements.

The AXAF VETA-I mirror ring focus measurements were made with a HRI (microchannel plate) X-ray detector. The ring focus is a sharply focused ring formed by X-rays before they reach the VETA-I focal plane. It is caused by spherical aberrations due to the finite source distance and the despace in the VETA-I test. The ring focus test reveals some aspects of the test system distortions and the mirror surface figure which are difficult or impossible to detect at the focal plane. The test results show periodic modulations of the ring radius and width which could be caused by gravity, thermal, and/or epoxy shrinkage distortions. We expect that a similar test for the finally assembled mirror of AXAF-I will be highly valuable.

We describe the fabrication of smooth electroformed replicas from gold-coated ceramic and lacquer-polished glass mandrels. We show that lowering the temperature of the plating both improves the surface quality of replicas produced from lacquer-polished substrates, although not to the levels that can be achieved using ceramic substrates. The low surface roughness and high ductility of electroforms make them attractive alternatives to conventional silicon and mica substrates for the production of bent and conformable multilayer optics. We describe preliminary work on multilayer coating an electroform produced from a sapphire master.

Fresnel zone plates have recently been used as the focusing optic for hard x-ray (5 - 11 keV) microscopy techniques. Fresnel zone plates used in the hard x-ray regime focus by constructive interference effects based on the phase modulation of the incident x-ray beam and have experimentally been shown to focus 20 - 30% of the incident photons to less than a one- micron focal spot. The materials of choice for these zone plates have been Al, Cu, Ni, and Au. The focus of this work is the theoretical optimization of the focusing efficiency of phase- modulating Fresnel zone plates in the hard x-ray regime by appropriate material selection. The optimal materials for three different energy ranges will be examined (1 - 5 keV, 5 - 20 keV, and > 20 keV) and a discussion of the selection criteria involved will be presented.

The scientific instrumentation onboard the Italian X-ray astronomy satellite SAX foresees X- ray imaging Mirror Units (MU) operating in the energy range 0.1 - 10 KeV with spatial resolution of 1 arcmin HPR. The MU are composed of thirty nested confocal and coaxial very thin double cone mirrors, made by a nickel electroforming replica technique. The paper presents the results obtained with the Engineering Qualification Model of the MU, which are well within the scientific requirements.

The European Space Agency's high throughput X-ray Telescope XMM (X-ray Multi Mirror Mission) has three modules each consisting of 58 highly nested monolithic Wolter I mirrors. The mirrors have diameters in the range between 300 and 700 mm, an axial length of 600 mm and a focal length of 7.5 m. Due to the high packing density within the mirror module the mirror shells have to be sufficiently thin, and due to the high number of mirrors the shells have to be as light as possible. In order to meet these requirements Carl Zeiss and Dornier have developed the CFRP/EPOXY mirror shell technology under ESA contract. In this paper the development and production of carriers of various sizes will be reported. It will be shown that the CFRP laminate with the lay-up chosen by Dornier is a good substrate for the replication of x-ray mirror shells.

We present an analysis of the geometric optics of spherically curved arrays of reflective surfaces. In particular, we consider optical devices in which reflective surfaces are arranged on a spherical interface and every ray reflects once from a reflector. The orientation of the reflective surfaces is not necessarily related in any way to the orientation of the interface. The analysis can be applied to any radiation that may specularly reflect from the reflectors. This may be reflection from stacks of mirrors or diffraction from the atomic planes. In this paper the principles are applied to x-ray optical systems such as capillary arrays and curved crystals. The calculations are used to find optimum configurations of reflective arrays for applications such as x-ray condensers and telescopes, to find the tolerances to which reflective arrays must be constructed, and to find the conditions where primary aberrations are eliminated.

The ESA High Throughput X-ray Spectroscopy Mission (XMM) is a telescope with three modules each consisting of 58 highly nested Wolter I mirrors with a focal length of 7.5 m. Envisaged resolution for an XMM module is 27 arcsec Half Energy Width at 8 keV x-ray energy. Due to the high packing density of the mirror shells within such a telescope, thin walled and light weight mirrors are required. In this paper the results of production, integration and performance tests of XMM CRFP/EPOXY mirror shells of all sizes (diameters from 300 mm to 700 mm; length equals 600 mm; wall thickness from 0.7 mm to 1.3 mm) for the XMM telescope will be reported.

We have developed a new method to make very thin mirror for the high throughput X-ray telescope, whose design goal of an angular resolution is 1 arc min half power diameter. In this method, aluminum mirror substrate is figured by diamond machining using special support made of water-soluble adhesive. The smooth surface is obtained by dip lacquering and the reflective layer is gold coated on this surface by the vacuum deposition. By means of this method, we have made test conical mirrors with a diameter of 150 mm, a height of 100 mm, a grazing angle of 0.6 degree and various thickness. We found that this method can provide very thin substrate of thickness down to 0.3 mm. The first results of mechanical and X-ray test indicate that angular resolution is 1.7 arc min half power diameter for 2 stage conical mirror system.

In this paper, conical foil x-ray telescope technology is reviewed and performance predictions of the Danish Space Research Institute XSPECT telescope design are conducted. Analysis includes discussion of geometrical aberrations, diffraction effects, assembly and alignment errors, and optical fabrication errors. NASA's Optical Surface Analysis Code and Encircled Energy for Grazing incidence optics computer codes are used to predict geometrical performance and model degradation effects of residual surface irregularities. Results are incorporated into a system error budget and parametric image quality predictions are performed. Finally, a summary of image quality predictions and an evaluation of conical foil telescope technology for space astronomy applications are presented.

We have investigated the propagation of the characteristic radiation of the Mo and Re atoms through the planar X-ray waveguides. It is established that if the number of reflections in the waveguide channel is sufficiently large, it is necessary to take into account the scattering of the beam at the roughnesses of the channel walls for the description of the angle distribution of the radiation at the exist of the waveguide. One of the possible systems for scanning the objects by the X-ray beam on the base of the planar waveguides is proposed.

In the present paper, we describe X-ray images obtained using planar, square pore MCPs in `point-to-point' focusing mode. Angular resolution of 5 arcminutes fwhm has now been measured for full-field illumination of a hydrogen-reduced Galileo MCP (29 mm active diameter; approximately 44,000 active channels). Secondly, we report some preliminary metrology of square-pore microchannel plates using atomic force, scanning electron and optical microscopies. Finally, we extend our study of spherically-slumped, round-pore Philips MCPs operated as X-ray `beam expanders'.

We are developing a novel x-ray lens based on a 1D analogue of the optical system of the lobster's eye. The lobster eye lens consists of a large number of flat reflecting surfaces with 100 micrometers separation between adjacent surfaces. We have used silicon micromachining to fabricate arrays of 100 micrometers sized optical elements in <110> oriented single crystal silicon wafers. We used a concentrated KOH solution to anisotropically etch single crystal silicon wafers; the resulting surfaces were aligned with the <111> planes perpendicular to the face of the wafer. The pores were 50 micrometers wide and 800 micrometers deep, for an aspect ratio of 16:1. We report on the fabrication techniques and measurements of the surface microroughness of the etched surfaces.

Passage of a ribbon X-ray photon beam through amorphous materials is investigated by solving a kinetic equation in one-group approximation. It is shown that decrease in the beam thickness leads to decreased background level consisting of scattered photons. The study of the beam passage through a polycapillary detector showed that there is a possibility to effectively detect X-ray photons with great precision.

General properties of Kumakhov lenses for Roentgen radiation and neutron beams are discussed. The role of waveguides surface roughness and some problems of the source and lens connection are investigated. Roentgen filter for energies >= 20 keV is proposed.

Experimental investigation of Kumakhov lenses for an image transfer by means of X-ray radiation is discussed.

Kumakhov lenses making consist of the creation of X—ray optical systems with certain, beforehand set parameters ensuring the solution of one or another functional problem. It means that lens as manufactured article must work in concrete conditions, have a focal spot just such type, shape and size, con— form to required energy range, etc. , and in spite of all this provide gain in operational characteristics (intensity, divergence, resolution, a.o. ), either simplify exploitation with preservation of these parameters or give new possi— bilities in comparison with existing traditional methods.

Multilayer mirrors of Co, Ni or Ru with spacer layer of C or B₄C are fabricated by electron-beam deposition with ion polishing of all metal layers. Improved performance over previous work is obtained for the mirrors containing Co and Ru. Very smooth boundaries are obtained for Ni films, however, this smoothness is only obtained for coatings with a small number of layers.

The optics of a Dall-Kirkham telescope and a Rowland grating have been coated with ion- beam-sputtered SiC in the 2-m mirror coating facility at Goddard Space Flight Center with a newly acquired deposition system. During the deposition system test runs we verified two optical properties of thin SiC films that had been suggested from calculations: (1) the visible reflectivity is sensitive to the thickness of the SiC layer and (2) a substrate of Al (as opposed to glass) improves the visible reflectivity of the coatings. In addition, we found the slow decay in the far-UV reflectivity exhibited by ion-beam-sputtered SiC coatings stored in a desiccator could be significantly retarded by storage in vacuum. We present the far-UV effective area of the telescope and spectrometer that we plan to fly on NASA sounding rocket 36.109UG in September 1993.

We report designs of multilayer narrowband reflective x-ray coatings that operate at non- grazing angles of incidence. The coatings are designed for the x-ray region from 0.1 nm - 7 nm with angles of incidence (measured relative to the film surface normal) (theta) ₀, ranging from 45 degree(s) - 85 degree(s). At 85 degree(s) angle of incidence the peak reflectance is more than 65% at 0.44 nm with bandwidth less than 0.006 nm. The grazing angle of incidence provides reflectance of more than 90% but without any spectral discrimination. This design provides very high spectral purity with reflectances as high as 65% for angles of incidence between 80 degree(s) and 85 degree(s).

Interfacial roughness correlation in W/C multilayer films with periods of 23 angstroms, 30 angstroms, and 37 angstroms is examined with x-ray diffraction using (lambda) in the 10 angstroms to 13 angstroms range and (lambda) equals 1.54 angstroms. Transverse scans through multilayer Bragg reflections are analyzed to determine the magnitude and lateral correlation length of the component of interfacial roughness that is perfectly correlated through the multilayer stack. The results are independent of wavelength, even though hard x rays sample match more deeply into the film, indicating that interfacial roughness is not changing through these films.

Laser-produced plasmas were imaged using a microscope consisting of spherical primary and secondary mirrors that were coated with 40 Mo/Si periods and had peak reflectance of 60% at a wavelength of 130 angstroms. Niobium, gold, and aluminum targets were irradiated by up to 24 beams of the Omega laser at the Laboratory for Laser Energetics at the University of Rochester. Magnified images were recorded on Kodak 101 film, and the resolution was limited by the 10 micrometers emulsion grain size. A variety of plasma emission features were recorded with 5 micrometers (0.6 arcsec) resolution in the object plane.

By varying the thickness of the layers in a multilayer down through the structure, it is possible to produce wide-band reflectors. We report measurements and modeling of the reflectivity of Ni/C, Mo/Si and W/Si supermirrors, at energies ranging from 8 to 130 keV, and discuss the performance of two possible applications: a Kirkpatrick-Baez telescope, and a multiwavelength hard X-ray focusing reflector. The supermirrors perform as expected, and model-fits over the full range have been attempted with some success. We conclude that the supermirror coatings do indeed look very promising as hard x-ray optics for synchrotron applications, while some work on highly nested structures and supermirror coatings on very thin large substrates is necessary, before the feasibility of employing large-area supermirrors for hard X-ray astronomy is determined.

Traditional high-Z coated X-ray telescopes for the >= 1 keV range all have a loss of throughput with higher energies, owing to the inverse proportionality between the critical angle and energy. We have shown that this can, to some degree, be countered by employing multilayers on the outermost reflectors. A W/B₄C multilayer has been fabricated and its 8 keV X-ray reflectivity measured and modeled, yielding an interface-roughness of 3.6 angstroms. This measurement and the resulting model-fit form the basis for computing the performance of `AXAF-S'-sized conical and Kirkpatrick-Baez telescopes. Depending on the specifics of the design, a factor 3 - 5 increased throughput was obtained in a narrow energy band, or a 30 - 100% increase in a wider-band. This throughput ia gained at the expense of the throughput at 2 - 4 keV, which is reduced by 20 - 30%.

The Multi-Spectral Solar Telescope Array, a rocket-borne solar observatory, was successfully flown in May, 1991, obtaining solar images in eight XUV and FUV bands with 12 compact multilayer telescopes. We report on recent measurements of the performance of multilayer coated mirrors for the Multi Spectral Solar Telescope Array, carried out at the Stanford Synchrotron Radiation Laboratory.

This paper describes a new visible light photometer system and presents the results of a test program where visible light transmission has been measured for a variety of materials of varying thicknesses. From these measurements, equivalent absorption coefficients are presented for some of the materials commonly used in x-ray and extreme ultraviolet filters. Also presented are some criteria for quantifying light leaks through pinholes.

The rational behind optical filter design for satellite-borne soft X-ray telescopes is elucidated by a series of sample calculations. By way of example we present the filter designs for two filters to be flown on-board the Joint European X-ray telescope (JET-X).

In previous papers, we reviewed the development of multilayer optics, the successful application of this new technology to astronomical observations, and the evolution of astronomical multilayer optics instrumentation through several generations. These developments have resulted in the acquisition of sub-arc-second images of the sun in several wavelength bands, permitting solar structures to be simultaneously observed over temperatures prevailing in the chromosphere (approximately 10,000 K - 100,000 K), the transition region (approximately 100,000 K - 1,000,000 K) and the corona (> 1,000,000 K). In the present paper, we discuss the interplay between the scientific objectives of the astronomical investigation, and the properties of the multilayer coatings.

We give an experimental study of soft x-ray diffraction by various laminar multilayer amplitude grating mirrors made by electron beam lithography. The +1, 0, -1 diffraction order efficiencies in the grating rule scan model and their positions were measured using synchrotron radiation on the Super-Aco at L.U.R.E in the X-UV region, particularly above the silicon L edge. These efficiencies were compared with values obtained in the detector scan mode. Their diffraction pattern were analyzed and discussed with a model. We describe a modular X-UV spectrogoniometer (0 - 20 goniometer).

The Multi Spectral Solar Telescope ARray (MSSTA) is a rocket borne solar observatory that utilizes an array of multilayer coated telescopes to observe the solar atmosphere from the chromosphere to the corona, over a broad spectral range (VUV--soft X-rays). The instrumentation of the MSSTA is continuously evolved to incorporate new instrument concepts, and to improve its ability to investigate specific topics related to the structure and dynamics of the solar atmosphere.

The x-ray optical properties of X-Ray Telescopes (XRTs) on board Asca were evaluated with an x-ray pencil beam at ISAS 30 m x-ray beam line. The total effective area of four XRTs is obtained to be about 1300 cm², 800 cm², and 450 cm² at each energy of 1.5 keV, 4.5 keV, and 8.0 keV, respectively. These values are about 15% less than those calculated by ray tracing method in an ideal case. The shadow effect of closely packed foils might be the main reason for the degradation of effective area. The Point Spread Function of XRT was also measured by an x-ray CCD. We have also measured the contamination of stray light, which were caused by the one time reflected photons (by primary or secondary mirror) and photons reflected on the back side surface of the mirror shells. The stray light profile and intensity were consistent to the results simulated by the ray tracing.

We have recently completed construction of a high throughput, modest resolution soft x-ray monochromator installed at the Synchrotron Ultraviolet Radiation Facility of the National Institute of Standards and Technology. Although this monochromator will be used primarily to characterize the optical properties of multilayer-coated x-ray optics, the versatility of the instrument will enable us to measure such properties as reflectivity, transmission, diffraction, and scatter of a variety of components. We present measurements of monochromator throughput and resolution.

Originally developed as an ion source for ion accelerators, the Duoplasmatron has also served as a VUV line source in monochromators. We have adapted and modified the Duoplasmatron, historically used at ambient conditions, for use in the vacuum chamber of the Diffraction Grating Evaluation Facility at NASA/GSFC. Construction, operational parameters and maintenance of the light source will be discussed.

Verification of component specification and EUV optical performance for the diffraction gratings of the normal incidence EUV spectrograph of SOHO/CDS is discussed. This discussion includes: a comparison of experimentally obtained EUV spectral images of a point source with corresponding ray trace analysis, in-band Lyman alpha leak determination, verification of toroidal radii of curvature, verification of blaze direction by calculation and VUV measurement, and zero order efficiency at 124 nm.

A new simulation method has been developed for evaluating the performance of a monochromator whose grating is exposed to intense undulator radiation. Analytic expressions for the thermally deformed surface figure and distorted groove pattern of the grating are determined first by a finite element method and then they are incorporated into a ray tracing procedure. The method is applied to a simple beamline optics consisting of a U3.9 undulator of the Advanced Light Source and a water-cooled metal grating to see whether this objective monochromator can stand for heat load without degrading its designed performance. The results show that the simulation method is capable of evaluating the performance of a thermally distorted grating and that the heat load would not cause any significant degradation in the spectral resolution and throughput.

A facility for the calibration of X-ray Space Instrumentation has been established for the Daresbury Synchrotron. The facility provides a continuously tunable beam with (Delta) (lambda) /(lambda) <EQ 10^-4 in the energy range from approximately 5 kev to more than 20 kev. At selected energies in the interval from 6 kev to 12 kev, the facility features a 1D sheet of X-rays, approximately 200 mm wide, obtained from an extremely asymmetric reflection in large perfect crystals of Si. The beam is collimated to < 20 arcsec. Data from tests using large (approximately 250 mm long) beam expander crystals in the energy range from 6 - 12 kev are presented. The planned calibration of the two X-ray telescopes (XSPECT/SODART and JET-X) will be described.

The use of an optical bench operating with UV or visible light, provide an easy and quick way for making a first assessment of the quality of replicated grazing incidence x-ray optics. The mirror to be analyzed is fully illuminated by means of a collimated beam of light and the image at the focal plane is analyzed with a CCD camera. The limit of this approach is given by the diffraction effect which could be important in the visible due to the large obscuration factor which is intrinsic to grazing incidence optics. The paper presents an analysis of the diffraction effect and how to separate the intrinsic aberrations from the diffraction. The use of an UV source (275 nm) is also reported in order to minimize the diffraction effects.

In 1991 a group of scientists from the Angara 5 pulsed power facility at the Kurchatov Institute in Troitsk, Russia had determine the thermal emission from an implosion of xenon gas onto an annular, molybdenum doped foam liner to be 30 TW/cm². This represents an extremely efficient conversion of energy into a high fluence radiation field. In order to verify this claim and better understand the process of producing radiation by means of a Z- pinch plasma device, a series of experiments were proposed through a collaboration from Sandia National Laboratory-Albuquerque, Los Alamos National Laboratory, and Lawrence Livermore National Laboratory.

An X-ray standing wave technique was used to characterize the interface roughness of multilayer structures. Standing wave fields of X-rays in multilayers are described in terms of a modified optical matrix. To include the interface roughness effect, Fresnel reflectance and transmittance coefficients in the matrix were modified. A Ni/C multilayer with about 54 angstroms periods was analyzed by X-ray diffraction and by the X-ray standing wave technique. The ratio between second and third Bragg reflection peaks suggested an expansion of nickel layer thickness. The X-ray standing wave measurement showed a reduction of nickel layer density, suggesting the diffusion of nickel atoms and formation of nickel-carbon complex. Interface roughness was estimated to be about 10 angstroms from the calculation at 85% bulk density of nickel, suggesting the diffusion of nickel.

A double mirror multilayer monochromator was constructed for the purpose of irradiating live cell cultures at the Synchrotron Radiation Center, University of Wisconsin-Madison. The monochromator is designed for the soft x-ray region with photon energies between 273 eV and 2400 eV. Multilayer mirrors with 55 bilayers of W/C and a bilayer spacing of d equals 3.0 nm are sputter deposited on Si substrates. By proper masking of the sputtering sources, variation in the bilayer spacing over the area of the mirror is minimized. The use of suitable filters with a Si(Li) detector allows determination of the spectral output of the monochromator. The output power of the monochromator between 273 eV and 900 eV is measured. Application of the monochromator to radiation biology and materials science are discussed.

The Institute of Roentgen Optical System (IROS) has created four generations of X-ray lenses. The first lens generation was fabricated from the single capillaries with diameter about 0.4 mm. The second lens generation, from polycapillaries which had the channel size up to 5 - 10 micrometers . The third lens generation represents monolithic lenses which completely were drawn or caked in the furnace. For the last two years we mastered the new fourth generation of the X-ray lenses. The X-ray capillary optics which we created presently finds expanding applications in instrument engineering, ecology, microelectronics, astronomy, and medicine. This paper is devoted to the results obtained lately in the IROS.

Film was chosen as the detector for the Multi-Spectral Solar Telescope Array (MSSTA), a sub-orbital solar observatory designed to operate over the entire soft x-ray, extreme ultraviolet (EUV), and far ultraviolet (FUV) spectral regime. In order to accurately calibrate the solar images obtained on the initial May 13, 1991 MSSTA flight, and to optimize the film loads for the diverse telescopes being developed for the MSSTA re-flight, we performed extensive calibrations at the NIST SURF II and the Stanford Synchrotron Radiation Laboratory synchrotrons. In addition to detailed studies of the MSSTA flight films (XUV-100 and 649), we also measured the performance characteristics of Kodak Technical Pan 2415 film, and the Agfa 10E56, 10E75 and Ilford HOTEC holographic emulsions. These measurements yielded valuable information concerning the soft x-ray/EUV/FUV response of the films and provided important insights into the physical properties of the films and their behavior after prolonged exposure to high vacuum.

The optical performances of the spectrometer for the SOHO/UVCS instrument have been tested. A laboratory evaluation unit of the spectrometer assembly consisting of the structure equipped with breadboard models of the entrance slit assembly, a grating drive mechanism mounting a toroidal grating and a MAMA detector has been integrated and aligned. Both tests with visible and UV radiation have been performed. Aberration and stray light measurements have shown satisfactory performances of the instrument almost in compliance with the scientific requirements.

Deposition possibility of small d-spacing (d equals 0.7 - 3 nm) multilayers on the basis of the material combinations W/Sb, W/Sc, Cr/Sc, Fe/Sc and their utilization as dispersive and focusing elements for the photon energy range E > 0.3 kev have been investigated. The use of the normal incidence spherical multilayers W/Sb, W/Sc and Cr/Sc for imaging of a high temperature laser produced plasma within the `water window' spectral range (0.3 < E < 0.5 kev) is presented.

Absolute calibrated multichannel devices based on plane and spherical multilayer mirrors and transparent filters have been used for spectral investigation of high-temperature plasma in a soft X-ray range. Possibility of optimization of the multilayers and filters to obtain maximum values of the channel transmittance and contrast are discussed.

The instruments on board our Normal Incidence X-ray Telescopes payload and the results obtained during the most recent flights will be described. The payload was launched three times during the 1991 - 1993 period, the last time on April 12, 1993. It contained a main telescope with an 11 inch diameter multilayer coated mirror for (lambda) equals 63.5 angstroms and photographic film as detector. Smaller telescopes for either (lambda) equals 304 angstroms or (lambda) equals 193 angstroms used electronic detection and direct transmission of analog or digital data to the ground station. The flight on the day of the solar eclipse in July 1991 gave us an opportunity to perform a soft-ray knife edge test with the limb of the moon. From the experiment we derive upper limits for the figure errors of the telescope mirror, and we conclude that large mirrors with diffraction limited resolution better than 0.01 arcsec can now be fabricated.

This paper presents measurements of specular and non-specular reflectivities of a W/Si multilayer with period d equals 135.1 angstroms. Angular dispersive measurements were performed at 8.05 keV and 59.3 keV, while energy dispersive measurements were made in the range of 17 keV to 130 keV. At an incidence angle of 1.57 mrad the fourth order Bragg- reflection is found at an energy of 125 keV with a reflectivity in excess of 50% and a bandwidth (FWHM) of 3%.

Since the recent invention by Kumakhov of polycapillary optics for the control of x-ray beams, a large number of potential applications have been identified. These include materials analysis techniques such as diffraction and microfluorescence, lithography, medical imaging applications such as angiography and mammography, and medical therapy. To develop and further identify these applications, precise knowledge is needed of the performance of a variety of capillary types for different source energies and geometries. Extensive measurements have been performed of transmission and exit divergence as a function of length, bend radius, x-ray source position, and x-ray energy (from 1 to 44 keV). X-ray source divergence was also varied; measurements were performed with point sources and synchrotron beams. The measurements were performed for a variety of polycapillary compositions, diameters, and geometries. In general, data agrees fairly well with Monte Carlo geometrical simulations.

We report on the application of low pressure ion beam sputtering combined with simultaneous (neutralized) ion beam polishing to the production of multilayer structures for x-ray optics. Initial examination of these structures by high resolution diffractometry at 0.154 nm indicates that the structures exhibit a high degree of structural perfection.

This document describes a proposal for a replica X-ray optics to be developed in Italy for NASA's X-ray spectroscopy mission AXAF-S. The program is based on state of the art technology for the production of replica X-ray optics. On the basis of the experience with the Jet-X mirror shells (to be flown on the Spectrum X-(gamma) satellite), a spatial resolution of 15 - 30 arcsec half power diameter (HPD) can be achieved for the AXAF-S optics. The characteristics of the proposed optical system are described and its performances evaluated by using the current baseline configuration for the array of X-ray calorimeters in the focal plane. The impact of the proposed replica X-ray optics is briefly outlined and a comparison with foil optics (1 - 3 arcmin HPD resolution) is carried out.

In recent years there has been an increased interest in the possible use of Ir as the reflecting surface in X-ray telescope programs. An X-ray study of such surfaces produced by sputtering of Ir on highly polished Zerodur flats is presented here. The study was performed using Fe K(alpha) ₁ (6.404 Kev) and Cu K(alpha) ₁ (8.048 keV) and includes measurement of total external reflection and scattering. The scattering measurement was made with three different instruments arrangements; one employed a 1D position sensitive detector for low resolution studies giving approximately 30 arcsec resolution (FWHM), and the other two arrangements employed channel cut crystals providing resolutions (FWHM) of 5 arcsec and 1 arcsec, respectively at Cu K(alpha) ₁. The reflectivity study revealed a very close correspondence with a theoretical model based on recently published optical constants. This important result shows that an Ir coating can be produced with nominal bulk density.