This PDF file contains the front matter associated with SPIE Proceedings Volume 8076, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.

Astronomical observation in the x-ray band (wavelength from ~100 - 0.1 Angstroms) must take place above the atmosphere on a space platform. The most effective means of collecting x-ray photons is with imaging optics. As such lightweight and high angular resolution optics are essential for continued success of x-ray astronomy in coming years and decades. In this paper, I will briefly review the development of x-ray optics for astronomy in the past few decades and outline the technical approaches that we have adopted at the Goddard Space Flight Center for developing lightweight and high resolution x-ray optics to enable small and medium missions that can be implemented in the current decade as well flagship missions that can be implemented in the 2020's.

The astronomy community has never flown a celestial source spectrograph that can resolve natural line widths in absorption the way the ultraviolet community since OAO-3 Copernicus in 1972. Yet there is important science to be mined there, and right now there are now missions on track to pursue it. We present a modified off-plane grating spectrograph design that will support high resolution (λ/δλ ~ 4000) in the soft x-ray band with a high packing density that will enable a modest cost space mission. We discuss the design for the WHIMEx mission which was proposed as an Explorer earlier this year with the goal of detecting high temperature oxygen in the Intergalactic Medium.

We report on recent progress with development of astronomical X-ray optics based on bent Si wafers. Recent efforts with Si wafers have been focused on new forming technologies such as method of deposition of thin layers. The role of substrates quality in performance of final mirror arrays, as required by large future space X-ray astronomy experiments was also studied.

We discuss a technique of shape modification that can be applied to thin walled (~; 100-400 micron thickness) electroformed replicated optics or slumped glass optics to improve the near net shape of the mirror as well as the mid-frequency ripple. The process involves sputter deposition of a magnetic smart material (MSM) film onto a permanently magnetic material. The MSM material exhibits strains about 400 times stronger than ordinary ferromagnetic materials. The deformation process involves a magnetic write head which traverses the surface, and under the guidance of active metrology feedback,locally magnetizes the surface to impart strain where needed. Designs and basic concepts as applied to space borne X-ray optics will be described.

In the frame of the technology development to be used for the Optical Payload of next future X-ray missions (such as e.g. New Hard X-ray Mission-ASI), a new set of manufacturing techniques were finalized by Media Lario Technologies (MLT), in collaboration with the Italian Space Agency (ASI) and the Brera Astronomical Observatory (INAF/OAB). The set of new technologies includes master manufacturing machines and processes, electroforming method, a vertical optical bench and metrology machines to support manufacturing and integration of mirrors. A magnetron sputtering PVD machine was upgraded and a Pt/C development study has been performed on the basis of the W/Si results obtained in the first phase of the study. New manufacturing technologies for highly accurate masters were developed and tested by mean of two full-size masters together with several dummies. A number of ultrathin Nickel-Cobalt focusing mirrors were manufactured via galvanic replication process from the masters and coated with Pt/C multilayer. Tests on substrate material, roughness and shape of the shell together with analysis on specimens were performed. Tests with AFM and XRR supported the development of the Pt/C multilayer which is the enabling technology for focusing high energy X-Rays. Several mirror shells were integrated into two demonstrator modules to assess the whole manufacturing process up to optical payload integration. The summary of the results from manufacturing and testing of specimens and mirror shells is reported in this paper together with a description of the technologies now available at MLT.

This paper gives a review and focuses on future possible applications of Kirkpatrick-Baez grazing incidence X-ray optical systems in space and astronomy, we also discuss in detail applications in other areas of science, where (in contrary to astronomy) these systems already have demonstrated their performance and advantages.

Different solar mission are in progress and others are foreseen in the next future to study the structure and the dynamics of the Sun and its interaction with the Earth. Different instruments devoted to solar physics are required to have high reflecting MultiLayers (MLs) coatings. For example, the Multi Element Telescope for Imaging and Spectroscopy (METIS) coronograph will fly on board of SOLar Orbiter (SOLO) mission to perform simultaneous observation at 30.4 nm (He - II Lyman - α line), 121.6 nm (H - I Lyman - α line) and in the visible range, therefore its optics will require high performances in a wide spectral region. It should be desirable to reach higher reflectivity as well as long term stability and lifetime, then different candidate coatings will be considered. The Sounding - Rocket Coronographic Experiment (SCORE) is a prototype of METIS equipped with Mg/SiC optics and it has flown on board of a NASA sounding rocket. The Mg/SiC multilayers offer good performances in terms of reflectivity, but the long term stability and the lifetime have been preliminary investigated and there are open problems to be further studied. Besides standard Mo/Si multilayer, a possible alternative is represented by new multilayer structures based on well known Mo/Si stack in which the performances have been improved by superimposing innovative capping layers. Another alternative is represented by a recently developed multilayer based on an Ir/Si material couple. In this paper we review and compare the performances of such multilayer in all the spectral ranges of interest for SOLO.

We report on preliminary results of full aperture X-ray optical tests at the X-ray test facility at the University of Colorado (USA) of four test modules of Kirkpatrick-Baez (KB) X-ray optical systems performed in August 2010. Direct experimental comparisons were made between gold-coated optics of two novel substrates: glass foils and silicon wafers. The preliminary results are promising, with full-width half-maxima of full stacks being of order of 30 arcsec in 2D full arrangement. These results justify further efforts to improve KB optics for use in low-cost, high-performance space-borne astronomical imaging instruments for X-ray wavelengths.

ORIGIN is a medium size high-energy mission concept submitted to ESA in response to the Cosmic Vision call issued on July 2010. The mission will investigate the evolution of the Universe by performing soft X-ray high resolution spectroscopic measurements of metals formed in different astrophysical environments, from the first population III stars at z > 7 to the present large scale structures. The main instrument on-board ORIGIN will be a large format array of TES X-ray micro-calorimeters covering a FOV of 30' at the focal plane of a grazing incidence optical module with a focal length of 2.5 m and an angular resolution of 30'' HEW at 1 keV. We present the optical module design which is based on hybrid technologies, namely Silicon Pore Optics for the outer section and Ni electro-forming for the inner section, and we present the expected performances based on test measurements and ray-tracing simulations.

The Bepi Colombo mission will explore the Mercury planet and its environment. Probing of Hermean Exosphere By Ultraviolet Spectroscopy (PHEBUS) is one of the instruments of the payload. It is a double spectrometer for Extreme Ultraviolet (EUV) and Far Ultraviolet (FUV) spectral regions devoted to the characterization of Mercury's exosphere. In this work we will present the calibration philosophy that will be applied to the Flight Model, and explain how a full instrument calibration can be derived from the wholly characterization of the optical subsystems through the Mueller Matrix formalism. The experimental results concerning of PHEBUS prototype optical subsystems are presented, which have been performed in the 55 - 315 nm range by using the normal incidence reflectometer at LUXOR Laboratory (CNR - Institute for Photonics and Nanotechnology, Padova).

The Lobster eye design for a grazing incidence X-ray optics provides wide field of view of the order of many degrees, for this reason it would be a convenient approach for the construction of space X-ray monitors. In this paper, we compare previously reported measurements of prototype lobster eye X-ray optics called P-25 with computer simulations and discuss differences between the theoretical end experimentally obtained results. Usability of this prototype lobster eye and manufacturing technology for the nano-satellite mission is assessed. The specific scientific goals are proposed.

We present the development of novel coatings for the far and extreme ultraviolet (FUV-EUV). In the EUV above ~50 nm, the strong absorption of materials has precluded the development of narrowband coatings. An extensive research has been performed on the search and characterization of new materials with low absorption; the lanthanide series has been found to be a source of materials with relatively low absorption in the range of interest. The discovery of a wealth of materials with relatively low EUV absorption is basic to develop efficient multilayers, particularly with narrowband properties. In this way, we have developed multilayers based on Yb, Al, and SiO with narrowband performance in the 50-92 nm range; these are first narrowband coatings peaked above 70 nm. Our recent research on multilayers based on Eu, Al, and SiO provide promising results, with an increase in the peak reflectance versus Yb/Al/SiO multilayers, along with a peak wavelength that can be extended up to ~100 nm. For applications where FUV-EUV narrowband coatings have not been able to be prepared, we can design multilayers that address specific purposes, such as maximizing the reflectance ratio at two wavelengths or bands. Our first goal in this direction is the development of coatings with high 102.6 nm/ 121.6 nm reflectance ratio. Calculations predict that a high reflectance at Lyman β with a good rejection at Lyman α can be obtained through multilayer coatings. We are at the beginning of experimental research for this goal.

X-ray imaging techniques based on grating interferometers rely on transmission gratings to detect x-ray refraction and scattering in a sample. Gratings periods below 2 microns are challenging to realize due to the high aspect ratio of the structures. We propose a method to fabricate transmission gratings with sub-micron periods over centimeter areas by multilayer coating of a staircase (echelle) substrate. The advantage of this approach is the high aspect ratio of multilayer coating and the large area of the echelle substrate. The staircase pattern is etched on the surface of a silicon wafer through anisotropic etching. Multiple layers are deposited on the horizontal surfaces of the stairs by magnetron sputtering in a single run. The layers alternate between two materials of different absorption coefficients or refractive indices. The layer thickness d is designed to be (stair height)/2N, where 2N is the total number of layers. The incident xray beam is parallel to the layers and oblique to the wafer surface. Each stair of the echelle substrate forms a micro grating of period 2d, and the array of micro gratings together act as a single grating over a large area given the right continuity conditions. The grating period potentially can be below 100 nm. We present theoretical description of wave diffraction by the grating array, and results of the first fabrication test with magnetron sputtering deposition.

This report summarizes the results of an experiment dedicated to the observation of backward transition radiation in the EUV spectral region. This radiation was generated by an 855MeV electron beam at a molybdenum target. The radiation characteristics in the EUV region are compared to those in the optical region. It was shown that the radiation measured in the EUV region was more intense than theoretically predicted. As a result the EUV radiation yield seems to be sufficient for standard beam profile diagnostics.

At the Institute of Microstructure Technology (IMT) at Karlsruhe Institute of Technology (KIT) X-ray refractive line focus lenses have been developed. They consist of a large number of concave bi-parabolic lens elements made of SU8. To form a point focus two of these lens stacks, tilted by 90° with respect to each other around the optical axis, need to be arranged in the optical path. To increase their transmission, the Fresnel principle can be applied to the lenses to provide higher ratios of refractive power to absorption. The lenses are fabricated by deep X-ray lithography which allows to pattern high aspect ratio structures and gives the possibility to fabricate the lens elements tilted by 90° with respect to each other on a single substrate by tilted double exposure. Nevertheless, the aspect ratio is limited, due to the fact that the columns tend to collapse from capillary forces during fabrication if they exceed a certain height. To overcome this issue and to simplify the fabrication process a new type of lenses as well as a method to fabricate refractive large aperture lenses has been developed recently at IMT. These lenses are fabricated out of a structured polyimide film which is cut into a calculated shape and rolled around a glass-fiber core. The structure on the film itself consists out of triangular shaped ribs. The lenses provide the advantage of Fresnel lenses and also provide a point focus through their approximate rotational symmetry. The full width at half maximum (FWHM) of the focal spot of such lenses is mainly determined by the height of the triangular ribs. Such X-ray optical elements are well suited to be used as condenser lenses, because they provide efficient illumination of an area in the exit working distance. To increase the lens performance, the lens fabrication process has been optimized. In the paper we provide information on how the lenses where improved and present results from tests with X-ray tube sources.

We report on our efforts in design and construction of a compact Extreme Ultraviolet (EUV)-pump-probe microscope. The goal is the observation of formation of nanostructures, induced by a femtosecond (fs)-laser pulse. The unique interaction processes of fs-laser radiation with matter open up new markets in laser material processing and, therefore, are actively investigated in the last decade. The resulting "sub 100 nm"-structures offer vast potential benefits in photonics, biotechnology, tribological surface design, plasmonic applications and production of nanoparticles. Focused fs-laser radiation causes a local modification resulting in nanostructures of high precision and reproducibility. However the formation dynamics is not well understood. Research in this field requires high temporal and spatial resolution. A combination of fs-laser and EUV-microscope provides a tool for "in situ"-observation of the formation dynamics. As exemplary structures to be investigated, we use nanojets on thin gold films and periodic surface structures (ripples) on dielectrics. In the future, the EUV-pump-probe microscope can become a versatile tool to observe physical or biological processes. Microscopy using EUV-light is capable of detecting structures on a scale down to several tens of nanometers. For detailed investigations a compact EUV-microscope has been realized utilizing O^VI Balmer-alpha radiation at 17.3 nm coming from a discharge produced oxygen plasma. As optical elements a grazing incidence elliptical collector and a zone plate with a width of outermost zone of 50 nm and a spectral filter to avoid chromatic aberrations are used. The detector is a fast gated microchannel plate with a pore size of 2 microns contacted by a low impedance transmission line. The expected spatial resolution of the setup is better than 100 nm and the time resolution is better than 1 ns. The newly developed EUV-microscope is a powerful tool for a wide field of investigations that need high time and spatial resolutions simultaneously.

This work concerns in measurement of characteristics of a XUV argon capillary laser, which was developed at the Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering. This laser generates at 46.9 nm in Ne - like Ar. Young's double pinhole experiment was realized to estimate spatial coherence of this laser system and to detect the beam profile. We used double pinholes drilled by Ti:saphire laser with four different pinhole separations. pinhole separations were 50 μm, 60 μ m, 100 μm and 150 μm. Apertures had oval shape with diameter 20 - 25 μ m. Interference structure was detected by XUV CCD camera with resolution 512x512 pixels. This work contains also short overview about sources of XUV radiation.

The requirements for multilayered x-ray elements for diffraction quality imaging optics (EUV - lithography, x-ray microscopy) achieves 0.2-0.3 nm roughness in spatial frequency range 10^-3 - 10³ mcm^-1; it's also true for the substrates. Although, there are plenty of publications on studying a surface, when it comes to angstrom-quality substrates there is still a problem. In some cases we observe, standard methods like x-ray diffuse scattering (XRDS), atomic force microscopy (AFM) and optical interferometric microscopy (OIM) give notably different results in surface characterization. The goal of the attestation procedure is choosing the sample for sputtering a multilayer coating with better reflection properties, that's why it's important to understand the physical causes of the difference and get reliable information about the surface. In this work we discuss the limitation for aforesaid standard methods. OIM is seems to be inapplicable for supersmooth surface investigation because of applying references. It's also shown, that examination substrates with damaged layers in the volume (caused, for example, by ion-beam etching) by XRDS can lead to incorrect results. Imaging systems are composed by nonplanar optical elements with radiuses from 10 mm to 1 meter. That makes impossible using hard x-rays and also limited AFM applicability to high frequencies. Therefore, we propose the diffuse scattering of soft x-rays as an alternative approach. We also describe a new reflectometer, based on soft x-ray and visible light diffuse scattering, which can be used for surface investigation in middle and high spatial frequency ranges for both plane or curved substrates.

The most promising wavelength for the next generation EUV lithography in terms of maximizing throughput of an optical system was found to be 6.63nm, where highest peak reflectivity is expected at this wavelength using La(La₂O₃)/B₄C structures. The optical throughput at 6.63nm is expected to be ~6 times lower than at 13.5nm due to the higher resolution of multilayers at the smaller wavelengths. La/B₄C and La₂O₃/B₄C multilayer structures were coated at RIT by using magnetron sputtering deposition technology. EUV reflectivity of the multilayers was tested at CXRO and NewSUBARU. The round robin measurements demonstrated a maximum deviation of 1.9% in the peak reflectivity and 0.0063nm in the peak position. The big difference in the peak value can be explained by presence of the higher harmonics in the probe beam at NewSUBARU which affected the accuracy of the measurements. The maximum peak reflectivity of 48.9% was measured from La/B4C multilayer at 6.68nm. Maximum reflectivity of La₂O₃/B₄C structure at this wavelength was 39.2% while reflectivity at 6.63nm was measured to be 42.68%. The measured band width of the reflectivity curves was about 20% lower than for ideal structures. La₂O₃/B₄C structure demonstrated a larger level of the imperfections resulting in much lower performance. EUV reflectivity of one of the La/B4C multilayers deposited in December 2000 was measured at NewSUBARU in January 2011 and the results were compared with the measurements performed in January 2001 at CXRO. The maximum reflectivity dropped from 42.6% to 37.6%. Reduction of the reflectivity band width from 0.044nm to 0.04nm was also observed.

A technique for fabrication of freestanding multilayers which are able to be used as optical elements in the soft X-ray and EUV ranges is reported. Two types of transmission mode elements have been developed: phase retarders for the aims of soft X-ray polarimetry and thin film spectral filters. A variety of phase retarders on the base of Cr/Sc, Cr/C, V/B4C and W/B₄C freestanding multilayers were designed for a spectral region of "water window" (λ≈ 2-4.5nm) 2 - 4.5 nm). The possibility to yield the phase shift between s- and p-polarizations as high as 90º at equal transparencies of these polarizations of 0.4% was experimentally demonstrated with Cr/Sc phase retarder close to the Sc L-edge of absorption (λ = 3.11 nm). The set of freestanding absorption filters Cr/Sc, Mo/C, Zr/Si, Zr/Al with spectral windows within 2.2 to 22 nm wavelength range was developed for the aims of hot plasma diagnostics. We also fabricated Al/Si structures with supported mesh, which are transparent in the range λ = 17 - 60 nm, for application in the sun astronomy. The sample of 160 mm in diameter Mo/ZrSi2 spectral purity filters with transparency of 70% (λ = 13 nm) was fabricated as the probable component part of industrial EUV lithography tool. The preliminary testing of heat load withstandability was fulfilled for a number of freestanding multilayers consisting of Si, Zr, Mo and silicides of both metals. It was found that Mo/ZrSi₂ structure is the challenge to withstand intensive heating up to 800 - 850°C.

Due to recent progress in short-period multilayer mirrors manufacturing, a real opportunity of nanoscale space resolution imaging in the XEUV range is appeared. Traditional manufacturing and surface shape characterization techniques do not meet the requirements. This paper reports on some new methods and technologies of measurement and surface shape correction, developed in IPM RAS. Last experimental results in manufacturing and surface shape studies of spherical and aspherical mirrors and objectives for X-ray optics are presented, as well as reflection characteristics of normal incidence multilayer mirrors made in IPM RAS. The advantages of using the multilayer optical elements for the diffraction quality imaging in comparing with Frenel's zone plates are discussed. There are also proposed some new applications for multilayer-based reflecting optical elements.

Research in ultrafast nanoscale phenomena requires high spatial and temporal resolution detectors. Optical imaging microscopes achieve high time resolution but low spatial resolution and scanning microscopes vice versa. Extreme ultraviolet imaging microscopy closes this gap but demands a suited two dimensional detector for efficient use of photons and simultaneously enabling fast gating. We use a micro-channel plate photoelectron multiplier together with a phosphor screen as a detector. We pulse the operation voltage of the electron-multiplier for 1.25 ns. Only during that time the detector is highly sensitive to extreme ultraviolet light. A custom built impedance-transformer delivers high currents into the plates' capacitance. This leads to a short charging time and ensures a narrow temporal sensitivity window. We analyzed the following attributes of the detector system: - Temporal behavior is measured by femtosecond illumination with high harmonics generation radiation at different relative delays. The sensitivity curve has a width of 2 ns. Electronic timing jitter is below 150 ps. - Spatial resolution is determined by mapping the shadow of a sharp edge on the detector. The smearing gives information about the modulation transfer function. The resolution limit according to the Rayleigh criterion is at 12 lp/mm or a minimum resolvable pitch of 80 μm. - Spectral sensitivity of the detector is calibrated for extreme ultraviolet wavelengths ranging from 1 nm to 30 nm at the PTB facility at the BESSY2 synchrotron. In summary the detector provides a spatial resolution down to 80 nm and a time resolution shorter than 2 ns using a discharge produced plasma EUV source and a zone plate based microscope with a magnification of ~ 1000x. This is a highly interesting combination and will help to investigate a variety of short time processes in nanoscience.

We present the CODEX sounding rocket payload, a soft x-ray (0.1-1.0 keV) spectrometer designed to observe diffuse high-surface brightness astronomical sources. The payload is composed of two modules, each with a 3.25° x 3.25° field of view defined by a stack of wire grids that block light not coming to a 3.0 m focus and admit only nearly-collimated light onto an array of 67 diffraction gratings in an off-plane mount. After a 2.0 m throw, the spectrum is detected by offset large-format gaseous electron multiplier (GEM) detectors. CODEX will target the Vela supernova remnant later this year to measure the temperature and abundances and to determine the contributions of various soft x-ray emission mechanisms to the remnant's energy budget; resulting spectra will have resolution (E/▵E) ranging from 50 to 100 across the band. CODEX is the third-generation of similar payloads from the University of Colorado, with an increased bandpass, higher throughput, and a more robust mechanical structure than its predecessors.

CODEX is a sounding rocket payload designed to operate in the soft x-ray (0.1-1.0 kV) regime. The instrument has a 3.25 degree square field of view that uses a one meter long wire grid collimator to create a beam that converges to a line in the focal plane. Wire grid collimator performance is directly correlated to the geometric accuracy of actual grid features and their relative locations. Utilizing a strategic combination of manufacturing and assembly techniques, this design is engineered for precision within the confines of a typical rocket budget. Expected resilience of the collimator under flight conditions is predicted by mechanical analysis.

Mars-XRD is an X-ray diffractometer developed for the in situ mineralogical analysis of the Martian soil. The main components of the Mars-XRD experiment are: a Fe55 radioactive source, a collimator and a CCD-based detector system. For spectroscopic requirements and quality of the machined micrograin of the sample, the beam section should not be larger then 1 × 10 mm² at sample distance. The current collimator baseline is based on a two-windows system that uses about 20% of the total source emitting surface. To improve the X-ray flux, we are studying a collimator with converging blades which permits to use the entire source emission and tune the beam section. In order to better estimate the efficiency of this collimator and because of the high number of variables, a C++ program has been written that look for the best blades configuration among billion of combinations. In addition to the collimator configuration, this software simulator gives the sample photons distribution for different angles of the tilt of the source and for each couple of blades. The optimized collimator transmits a flux 30% higher than a system with blades with the same angular aperture and 5 times higher than a two windows collimator. Moreover the target photon distribution is a triangle function well focused on the sample surface instead of an irregular function obtained with the previous system. Higher performances arise with the source perpendicular to the source-sample direction. Thanks to this optimization we expect to strongly improve the resolution of the diffraction pattern which is the main goal of the current activities of the instrument development. This software simulator could be used also for the optimization of collimator system for the other wavelength and applications (e.g. radiotherapy).