This PDF file contains the front matter associated with SPIE Proceedings Volume 9510, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing.

Over the past 16 years, NASA's Chandra X-ray Observatory has provided an unparalleled means for exploring the high energy universe with its half-arcsecond angular resolution. Chandra studies have deepened our understanding of galaxy clusters, active galactic nuclei, galaxies, supernova remnants, planets, and solar system objects addressing most, if not all, areas of current interest in astronomy and astrophysics. As we look beyond Chandra, it is clear that comparable or even better angular resolution with greatly increased photon throughput is essential to address even more demanding science questions, such as the formation and subsequent growth of black hole seeds at very high redshift; the emergence of the first galaxy groups; and details of feedback over a large range of scales from galaxies to galaxy clusters. Recently, NASA Marshall Space Flight Center, together with the Smithsonian Astrophysical Observatory, has initiated a concept study for such a mission now named the X-ray Surveyor. This concept study starts with a baseline payload consisting of a high resolution X-ray telescope and an instrument set which may include an X-ray calorimeter, a wide-field imager and a dispersive grating spectrometer and readout. The telescope would consist of highly nested thin shells, for which a number of technical approaches are currently under development, including adjustable X-ray optics, differential deposition, and modern polishing techniques applied to a variety of substrates. In many areas, the mission requirements would be no more stringent than those of Chandra, and the study takes advantage of similar studies for other large area missions carried out over the past two decades. Initial assessments indicate that such an X-ray mission is scientifically compelling, technically feasible, and worthy of a high prioritization by the next American National Academy of Sciences Decadal Survey for Astronomy and Astrophysics.

NASA's Marshall Space Flight Center (MSFC) engages in research, development, design, fabrication, coating, assembly, and testing of grazing-incidence optics (primarily) for x-ray telescope systems. Over the past two decades, MSFC has refined processes for electroformed-nickel replication of grazing-incidence optics, in order to produce highstrength, thin-walled, full-cylinder x-ray mirrors. In recent years, MSFC has used this technology to fabricate numerous x-ray mirror assemblies for several flight (balloon, rocket, and satellite) programs. Additionally, MSFC has demonstrated the suitability of this technology for ground-based laboratory applications—namely, x-ray microscopes and cold-neutron microscopes and concentrators. This mature technology enables the production, at moderately low cost, of reasonably lightweight x-ray telescopes with good (15–30 arcsecond) angular resolution. However, achieving arcsecond imaging for a lightweight x-ray telescope likely requires development of other technologies. Accordingly, MSFC is conducting a multi-faceted research program toward enabling cost-effective production of lightweight high-resolution x-ray mirror assemblies. Relevant research topics currently under investigation include differential deposition for post-fabrication figure correction, in-situ monitoring and control of coating stress, and direct fabrication of thin-walled full-cylinder grazing-incidence mirrors.

Alternative designs, arrangements and technologies for future astronomical X ray telescopes are presented and discussed.

The primary objective of the project VZLUSAT-1 is the development, manufacturing, qualification and experimental verification of products and technologies in Earth orbit (IOD – In-Orbit Demonstration). This work addresses the issue of X-ray monitoring for astrophysical applications. The proposed wide-field optical system has not been used in space yet. The proposed novel approach is based on the use of 1D "Lobster eye" optics in combination with Timepix X-ray detector in the energy range 3 - 40 keV. The proposed project includes theoretical study and a functional sample of the Timepix X-ray detector with multifoil wide-field X-ray "Lobster eye" optics. Using optics to focus X-rays on a detector is the only solution in cases the intensity of impinging X-ray radiation is below the sensitivity of the detector, e.g. while monitoring astrophysical objects in space, or phenomena in the Earth's atmosphere. On board the functions and features of Radiation Hardened Composite Housing (RHCH), Solar panels based on composite substrate and Hollow Retro Reflector Array based on composite (HRRA) will be verified. To verify the properties of the developed products the satellite is equipped by Health Monitoring system (HM). HM system includes temperature, volatiles, radiation and mechanical properties sensors. The custom ADCS algorithms are being developed within the project. Given the number of IOD experiments and the necessary power the 1U CubeSat is equipped with Composite Deployable Panels (CDP) where HM panels and additional Solar panels are located. Satellite platform is assembled from commercial parts. Mission VZLUSAT-1 is planned for 6 months with launch in 2016.

Among the methods to focus photons the diffraction in crystals results as one of the most effective for high energy photons. An assembling of properly oriented crystals can form a lens able to focus x-rays at high energy via Laue diffraction in transmission geometry; this is a Laue lens. The x-ray diffraction theory provides that the maximum diffraction efficiency is achieved in ideal mosaic crystals, but real mosaic crystals show diffraction efficiencies several times lower than the ideal case due to technological problems. An alternative and convenient approach is the use of curved crystals. We have recently optimized an efficient method based on the surface damage of crystals to produce self-standing uniformly curved Si, GaAs and Ge tiles of thickness up to 2-3 mm and curvature radii R down to a few meters. We show that, for curved diffracting planes, such crystals have a diffraction efficiency nearly forty times higher than the diffraction efficiency of perfect similar flat crystals, thus very close to that of ideal mosaic crystals. Moreover, in an alternative configuration where the diffracting planes are perpendicular to the curved ones, a focusing effect occurs and will be shown. These results were obtained for several energies between 17 and 120 keV with lab sources or at high energy facilities such as LARIX at Ferrara (Italy), ESRF at Grenoble (France), and ANKA at Karlsruhe (Germany).

ISS-Lobster is a wide-field X-ray transient detector proposed to be deployed on the International Space Station. Through its unique imaging X-ray optics that allow a 30 deg by 30 deg FoV, a 1 arc min position resolution and a 1.6x10^-11 erg/(sec cm²) sensitivity in 2000 sec, ISS-Lobster will observe numerous events per year of X-ray transients related to compact objects, including: tidal disruptions of stars by supermassive black holes, supernova shock breakouts, neutron star bursts and superbursts, high redshift Gamma-Ray Bursts, and perhaps most exciting, X-ray counterparts of gravitational wave detections involving stellar mass and possibly supermassive black holes. The mission includes a 3-axis gimbal system that allows fast Target of Opportunity pointing, and a small gamma-ray burst monitor. In this article we focus on ISS-Lobster measurements of X-ray counterparts of detections by the world-wide ground-based gravitational wave network.

Polarimetry is a powerful tool to interpret how the coronal plasma is involved in the energy transfer processes from the Sun’s inner parts to the outer space. Space polarimetry in the far ultraviolet (FUV) provides essential information of processes governed by the Doppler and Hanle resonant electron scattering effects. Among the key FUV spectral lines to observe these processes, H I Lyman α (121.6 nm) is the most intense. Some developing or proposed solar physics missions, such as CLASP, SolmeX, and COMPASS, plan to perform polarimetry at 121.6 nm. Classical solutions, such as a parallel plate of a transparent material, either MgF₂ or LiF, result in a modest efficiency of the passing polarization component. The development of more efficient linear polarizers at this wavelength will benefit future space instruments. A research has been conducted to develop polarizers based on (Al/MgF₂)_n multilayer coatings in a band containing 121.6 nm, to obtain a significant efficiency increase over plates. Coatings operating by reflectance resulted in a high efficiency after approximately one year of storage under nitrogen. In parallel, coating polarizers operating by transmittance have been prepared for the first time. Transmissive polarizers have the advantage that they involve no deviation of the beam. As a further benefit, the developed transmittance polarizers additionally incorporate filtering properties to help reject wavelengths both shortwards and longwards of a band containing 121.6 nm. Hence a polarizer combined with a filter is obtained with a single device. The combined polarizer-filter could enable a higher performance polarimeter for solar physics if the use of a separate filter to isolate Lyman α turns unnecessary.

This paper presents a new method to model the transverse scattering from random rough surfaces. It uses the same approach as our 2003 SPIE paper – PZ and LVS,¹ but considers the scattering in the direction perpendicular to the incident plane. For a given Power Spectral Density, a model surface is constructed by assigning a random phase to each spectral component. The incident wave is reflected from the model rough surface and then projected to an outgoing wavefront, which is then redistributed onto an even grid in the transverse direction, with corrections for the wave densities and the phase shifts. Fast Fourier transforms are used to calculate the transverse scattering pattern. This method provides the exact solution to the transverse scattering without small angle approximation. This solution is generally applicable to any transverse wave scatterings on random rough surfaces and is not limited to small scattering angles. This paper together with PZ and LVS¹ provide a complete solution for wave scattering on random rough surfaces in all directions. Examples are given for the Chandra X-ray Observatory optics. This method is also useful for the next generation X-ray astronomy missions.

Applications of wide field Lobster Eye X ray telescopes are presented and discussed. The wide field X ray optics was originally proposed for use in X-ray astronomy, but there are numerous other application areas as well.

Single layer thin films have been exposed to low energy alpha particles (4keV). Implanted doses are equivalent to those accumulated in 1, 2, 4 and 6 years of ESA Solar Orbiter mission operation. Two ions fluences have been considered. In order to change the total dose accumulated, for each ion flux the time of exposure was varied. Reflectance in the visible spectral range has been measured prior and after implantation. Results show no significant change in performances in gold and palladium, while a small decrease in performances is observed in iridium. The implantation rate does not seem to affect the experiment.

Analytical equations describing lobster eye optical parameters on dependence on its geometric parameters are presented. The paper partially gives review of main previously known results. At next, the paper gives new results discussing parameters, that were not included to previously published models but may be significant. The results are applicable for a Schmidt as well as for an Angel lobster eye and for some related multi-foil systems.

Schmidt lobster eye multi-foil optics allows high field of view and it can have small mass and dimensions. It makes the optic usable on small low-cost satellite mission that would permanently monitor selected sky area(s). In the paper, possible optical designs are presented. Presented designs are derived of existing optics specimen, therefore they should be technically feasible.

We examine a method for achieving zero intrinsic stress in thin films of iridium, chromium, and nickel deposited by magnetron sputter deposition. The examination of the stress in these materials is motivated by efforts to advance the optical performance of light-weight x-ray space telescopes into the regime of sub-arc second resolution. A characteristic feature of the intrinsic stress behavior in chromium and nickel is their sensitivity to the magnitude and sign of the intrinsic stress with argon gas pressure, including the existence of a critical pressure that results in zero film stress. This critical pressure scales linearly with the film’s density. While the effect of stress reversal with argon pressure has been previously reported by Hoffman and others for nickel and chromium, we have discovered a similar behavior for the intrinsic stress in iridium films. Additionally, we have identified zero stress in iridium shortly after island coalescence in the high adatom mobility growth regime. This feature of film growth is used for achieving a total internal stress of -2.89 MPa for a 15.8 nm thick iridium film with a surface roughness of 5.0 ± 0.5Å based on x-ray reflectivity (XRR) measurement at CuKα. The surface topography was also examined using atomic force microscopy (AFM). The examination of the stress in these films has been performed with a novel in-situ measurement device. The methodology and sensitivity of the in-situ instrument is also described herein.

A Laue lens is an innovative approach to focus x and gamma ray in the energy range from ~60 keV to 600 keV through Laue diffraction by a properly arranged array of crystals. Good candidates as optical elements for such lenses are selfstanding bent crystals, in which the permanent curvature is obtained by a controlled surface treatment. We present a study based on the dynamical theory of x-ray diffraction efficiency of bent Si, Ge and GaAs crystals. We demonstrate that optimizing the curvature and the thickness for a proper diffraction geometry, relatively light Si, Ge and GaAs crystals may diffract with the same or even higher efficiency than higher density mosaic crystals, such as Cu, Ag and Au also permitting to accurately design the diffraction angular range. Thus, the use of low-Z curved crystals in Laue lenses may permit an increase of the lens performance. This opens important opportunities for use in x-ray astronomy for space telescopes and in nuclear medicine for the localization of cancers in the human body.

We present a new approach to the numerical solution of Takagi equations, based on the Finite Element Method (FEM) that starting from a weak formulation of differential equations is much more versatile than the usual Finite Difference method (FDM). In particular, this is the only available approach that can easily handle with calculation where the free space propagation is required, as in the case of focusing by curved crystals, but also some crystals cut with special geometries that are useful for neutron monochromators.

We address the design, fabrication, and characterization of transmittance filters for the Ionosphere Photometer instrument (IP), developed by the Center for Space Science and Applied Research (CSSAR). IP, a payload of Feng-Yun 3D meteorological satellite, to be launched on 2016, is aimed to perform photometry measurements of Earth’s ionosphere by the analysis of the OI (135.6 nm) spectral line and N₂ Lyman-Birge-Hopfield (LBH, 140-180 nm) band, both of them in the far ultraviolet (FUV) range. The most convenient procedure to isolate a spectral band is the use of tunable transmittance filters. In many applications the intensity of the ultraviolet, visible and infrared background is higher than the intensity of the target FUV lines; therefore one of the most important requirements for transmittance filters is to reject (by reflecting and/or by absorbing) as efficiently as possible the visible and close ranges. In the FUV range, (Al/MgF₂)_n transmittance filters are the most common, and they are suitable to reject the visible and adjacent ranges. These materials present unique properties in this range: MgF₂ is transparent down to ∼115 nm and Al has a very low refractive index in the FUV that contrasts well with MgF₂. Narrowband tunable filters with very low transmittance at long wavelengths are achievable. The main data on the preparation and characterization of IP filters by Grupo de Óptica de Láminas Delgadas (GOLD) is detailed. In this proceeding we present (Al/MgF₂)₃ filters peaked at either 135.6 nm or at the center of the LBH band (∼160 nm). Filters were characterized in the 125-800 nm range (143-800 nm range for the LBH filter). After some storage in a desiccator, both coatings kept a transmittance of ~0.14 at their target wavelengths, with visible-to-peak transmittance ratios of 1.2·10^-4 (OI filter) and 1.3·10^-4 (LBH filter). One filter tuned at each target wavelength was exposed to ~300 Gy ⁶⁰Co gamma dose, with no significant transmittance change.

The application of thin film coating processes for the fabrication of diffractive X-ray optical elements like sputteredsliced zone plates or multilayer Laue lenses (MLL) is a very promising approach for X-ray focusing down to spot sizes of < 10 nm. However, for practical useful focal length in the order of several millimeters or a few centimeters, multilayer thicknesses of several 10 μm up to a few 100 μm are necessary in order to have large enough numerical apertures of the lenses. Currently one of the main challenges is to coat low-stress multilayers with large total thicknesses in the order of 100 μm. Usually sputter deposition results in thin films with significant compressive stress. With new material combinations such as Mo/MoSi₂/Si/MoSi₂ and W/WSi₂/Si/WSi₂ the overall stress can be reduced to almost zero if the individual thicknesses are properly adapted. In the case of these four-layer-systems only the period thickness dp follows the zone plate law. In case of Mo/MoSi₂/Si/MoSi₂, stress-free multilayers are obtained with dMo = 0.5*dp, dMoSi2 = 0.16*d_p and d_Si = 0.34*d_p.

Radiation with shorter illumination wavelength allows for extension of the diffraction limit towards nanometer scale, which is a straightforward way to significantly improve a spatial resolution in photon based microscopes. Soft X-ray (SXR) radiation, from the so called ”water window” spectral range, λ=2.3-4.4 nm, which is particularly suitable for biological imaging due to natural optical contrast, providing much better spatial resolution than one obtained with visible light microscopes. The high contrast is obtained because of selective absorption of radiation by carbon and water, being constituents of the biological samples.

We present a desk-top system, capable of resolving 60 nm features in few seconds exposure time. We exploit the advantages of a compact, laser-plasma SXR source, based on a double stream nitrogen gas puff target, developed at the Institute of Optoelectronics, Military University of Technology. The source, emitting quasi-monochromatic, incoherent radiation, in the “water widow” spectral range at λ = 2.88 nm, is coupled with ellipsoidal, grazing incidence condenser and Fresnel zone plate objective. The construction of the microscope with some recent images of test and real samples will be presented and discussed.

The wavelength diffraction limit, described by the Rayleigh criterion, can be overcome if short wavelength radiations are employed, thus it is possible to resolve smaller features by the use of radiation in the extreme ultraviolet (EUV) and soft X-ray (SXR) spectral ranges. In particular way, radiation from the “water window” spectral range, which extends between K-absorption edges of carbon and oxygen (280÷540 eV), could be used in order to obtain high-contrast biological imaging. Laser-plasma double stream gas puff target source is suitable for SXR microscopy in the “water window” spectral range, which recently allowed to develop a system, operating at He-like nitrogen spectral line λ=2.88 nm, which permits to obtain images with half-pitch spatial resolution of ∼ 60 nm, exposure time as low as a few seconds and represents an important alternative for high resolution imaging for biomedical applications, material science and nanotechnology using a very compact laser source. The goal of measurements, presented herein, is to show SXR images of various biological samples, proving high contrast in the “water window” and characterize in more detail such compact microscopy system, based on a laser plasma source with a double stream gas puff target and a Fresnel zone plate (FZP) objective. The influence of various acquisition parameters on the quality of the obtained SXR images, expressed in terms of a signal-to-noise (SNR) will be demonstrated. Moreover, because the measurements are performed on SXR images, similar measurements might be performed as a benchmark in order to characterize different imaging systems as well.

An X-ray spectrograph consisting of aligned, radially ruled off-plane reflection gratings and silicon pore optics (SPO) was tested at the Max Planck Institute for extraterrestrial Physics PANTER X-ray test facility. The SPO is a test module for the proposed Arcus mission, which will also feature aligned off-plane reflection gratings. This test is the first time two off-plane gratings were actively aligned to each other and with a SPO to produce an overlapped spectrum. We report the performance of the complete spectrograph utilizing the aligned gratings module and plans for future development.

In this work photoionized plasmas were created by irradiation of atomic and molecular gases by soft X-ray and extreme ultraviolet intense radiation pulses. Two different laser-produced plasma sources, employing a low energy Nd:YAG laser system (NL 129) and a high energy iodine laser system (PALS), were used for creation of photoionized plasmas. In both cases the SXR/EUV beam irradiated the gas stream, injected into a vacuum chamber synchronously with the radiation pulse. Radiation spectra, measured for photoionized plasmas produced in Ne and Ar gases, are dominated by L-shell emission lines except the Ne plasma produced using the high energy system where K-shell emission dominates. Additionally electron density measurements were performed by laser interferometry employing a femtosecond laser system synchronized with the irradiating system. Maximum electron density for Ne plasma, induced using the high energy system, reached 2·10¹⁸cm^-3. In case of employing the low energy system a detection limit was too high for interferometric measurements, thus only an upper estimation for electron density could be made.

Laser plasma sources of soft x-rays and extreme ultraviolet (EUV) developed in our laboratory for application in various areas of technology and science are presented. The sources are based on a laser-irradiated gas puff target approach. The targets formed by pulsed injection of gas under high-pressure are irradiated with nanosecond laser pulses from Nd:YAG lasers. We use commercial lasers generating pulses with time duration from 1ns to 10ns and energies from 0.5J to 10J at 10Hz repetition rate. The gas puff targets are produced using a double valve system equipped with a special nozzle to form a double-stream gas puff target which secures high conversion efficiency without degradation of the nozzle. The use of a gas puff target instead of a solid target makes generation of laser plasmas emitting soft x-rays and EUV possible without target debris production. The sources are equipped with various optical systems, including grazing incidence axisymmetric ellipsoidal mirrors, a “lobster eye” type grazing incidence multi-foil mirror, and an ellipsoidal mirror with Mo/Si multilayer coating, to collect soft x-ray and EUV radiation and form the radiation beams. In this paper new applications of these sources in various fields, including soft x-ray and EUV imaging in nanoscale, EUV radiography and tomography, EUV materials processing and modification of polymer surfaces, EUV photoionization of gases, radiobiology and soft x-ray contact microscopy are reviewed.

We report on the fabrication of novel diffraction gratings for soft x-ray and extreme ultra-violet (EUV) photon energies based on asymmetric-cut multilayer structures. Asymmetric-cut multilayers are highly dispersive and highly efficient gratings obtained by slicing a thick multilayer coating. Multilayer deposition techniques enable sub-ångström precision in layer thickness control, which leads to close to perfect blazed gratings. However, the final grating size is limited by the maximum multilayer thickness for which one can still control the layer thickness, stress and roughness. Here, we present a new approach in which we substantially extend the grating size by combining specially prepared substrates, thick multilayer deposition and final polishing. Gratings prepared by this method, like asymmetric multilayers deposited on plane substrates, are highly dispersive and efficient. Their extended size make them ideal for use in monochromators, spectrometers and pulse compressors.

A search for novel materials for making multilayers of high reflectivity has been driven by the vigorous demand towards miniaturizing photonics. A typical consumer of high performance multilayers (MLs) is the extreme ultraviolet lithography (EUVL) based on the 13.5 nm laser produced plasma (LPP) source. To sustain “Moore’s law” and print fine features below 10 nm on integrated circuits (IC), source of radiation for the EUVL has to shift towards even shorter wavelengths where 6.x nm wavelength seems to be immediate successor. However, the 6.x nm EUV lithography needs MLs of reflectivity performance above 70 % to support high volume manufacturing (HVM). It is clear that more work is required particularly on the development of MLs with high reflectance, stable to thermal heat and sufficient lifetime. In this work new MLs of B₄C/CeO₂ are deposited, analyzed and characterized for the first time. Combinations of X-ray reflectometry (XRR) and EUV reflectance measurements near resonance edge of boron are analyzed to derive structural and optical parameters of MLs. ML coatings of B₄C/CeO₂ MLs have shown similar reflectance performance with the leading candidate MLs around 6.x nm wavelength. Analysis shows that interlayer diffusion is a major reason for low reflectivity performance. Cross-sectional scanning electron microscopy (SEM) images of the MLs have proved formation of interlayer diffusion.

The ultimate goal of our research is to develop novel fabrication methods for high efficiency and high resolution X-ray optics. To this end, we have been pursuing the fabrication of several innovative diffractive/refractive optics designs. One such optic is the multilayer type Fresnel zone plate (ML-FZP). Our fabrication process relies on the atomic layer deposition (ALD) of two materials on a smooth glass fiber followed by a focused ion beam (FIB) based slicing and polishing. The ALD process allows much smaller outermost zone widths than the standard electron beam lithography based FZPs, meaning FZPs with potentially higher resolutions. Moreover, by depositing the multilayer on a cm long glass-fiber FZPs with very high optical thicknesses can be fabricated that can efficiently focus harder X-rays as well. A 21 nm half-pitch resolution was achieved using the ML-FZPs. Another optic we have been working on is the kinoform lens, which is a refractive/diffractive optic with a 100 % theoretical focusing efficiency. Their fabrication is usually realized by using approximate models which limit their success. Recently the fabrication of real kinoform lenses has been successfully realized in our lab via gray-scale direct-write ion beam lithography without any approximations. The lenses have been tested in the soft X-ray range achieving up to ~90 % of the calculated efficiency which indicates outstanding replication of the designed profile. Here we give an overview of our research and discuss the future challenges and opportunities for these optics.

Obtaining a high quality physical description of the layered structure of multilayer based optical coatings is an essential part of the optimization of their optical performance. Grazing incidence X-ray reflectivity (GIXR) is one of the most informative and easy-to-use non-destructive tools for the analysis of multilayer structures. The typical challenge of GIXR structural characterization is the reconstruction of the layered structure from fitting simulated data to experimental data. Here we present an example of the application of a newly developed, free-form, GIXR analysis to the characterization of heat induced structural changes in periodic La/B multilayers. This example shows that the developed algorithm is capable of reconstructing electron density profiles in cases where a classical non free-form approach generally fails.

Lightweight Asymmetry and Magnetism Probe project (LAMP) was proposed in China to observe the polarized radiation around 250 eV emitted by soft X-ray celestial sources, like puslars, active galactic, black hole binaries, etc. To produce the high efficiency soft X-ray polarizer for LAMP, we are developing Co/C, Cr/C, CoCr/C X-ray multilayers using magnetron sputtering and reactive sputtering with nitrogen. Hard X-ray grazing incidence reflectometry (GIXR) and soft X-ray reflectance measurements were used to study the interface and microstructure of different multilayers. In comparison to the multilayers deposited by normal magnetron sputtering, reactively-sputtered multilayers show higher reflectivity around 250 eV and lower interfacial roughness. As a result, Co/C, Cr/C, CoCr/C multilayers with smaller period can be made with respect to the multilayer fabricated using non-reactive sputtering. The X-ray performance of reactive sputtered Co/C and CoCr/C multilayers can be further improved by optimizing the deposition process.

We present a short review of our activities carried out in Tongji University (Shanghai, China) in the field of theory and technology of soft X-ray multilayer diffraction gratings. Diffraction gratings are widely used to study the structure and dynamics of a matter in laboratory and space by spectral analysis techniques. Combining multilayer and grating structures into a single unit allows to increase essentially both the spectral resolution and the efficiency of the diffraction optics. The unified analytical theory of soft X-ray diffraction from multilayer gratings operating in the single-order regime is briefly discussed. The single-order regime occurs when incident wave excites the only diffraction order and it is characterized by ultimately high diffraction efficiency tending to the reflectivity of conventional multilayer mirror. Our first experiments in fabrication of the blazed multilayer gratings by anisotropic etching of a silicon crystal with small roughness of the facet surfaces are described.

In this work, three TiO2 thin films with thicknesses of 22.7, 48.5 and 102.9 nm were grown on Si (100) substrates by the technique of electron beam evaporation. The films were deposited at a substrate temperature of 150°C with a deposition rate of 0.3 - 0.5 A/sec. The films thicknesses were characterized by spectroscopic ellipsometry and profilometry. The surface roughness was measured by AFM obtaining RMS of less than 0.7nm. Investigations performed by XPS method have shown that stoichiometric TiO₂ was obtained on all the samples with no suboxide presences. Reflectance measurements of the samples were performed in EUV and SX spectral regions from 25.5 to 454.2eV using synchrotron radiation. Analyzing the refractive index N=n+ik of TiO₂ thin films, optical constants (n,k) in this energy range were both determined by fitting the Fresnel equations with least-square fitting methods.

Probing of Hermean Exosphere By Ultraviolet Spectroscopy (PHEBUS) is a dual channels spectrometer working in the Extreme UltraViolet (EUV) and Far UltraViolet (FUV) range. It will be on board of ESA BepiColombo cornerstone mission and it will be devoted to investigate the composition, the dynamic, the formation and the feeding mechanisms of Mercury’s exosphere system. A consistent interpretation of the observational data collected by PHEBUS requires a deeply knowledge of its radiometric behavior. The Mueller’s matrix formalism can be adopted to derive an accurate radiometric model able to takes into account also the polarization state of the source observed by PHEBUS. Moreover, this theoretical model can be further verified and refined during an experimental ground calibration campaign. In this work we present the radiometric model derived for PHEBUS spectrometer together with some results obtained during the Flight Model (FM) ground calibration which is still ongoing. In particular, the obtained results employing this approach show that this is a complete and versatile method to perform the radiometric calibration of a generic space instrument.

An investigation on short-wavelength ablation mechanism of poly(1,4-phenylene ether ether-sulfune) PPEESand poly (1-hexadecene-sulfone) PHDS (Figure 9-10) by EUV radiation is presented. The goal of this work is to evaluate the ablation behavior with respect to the influence of wavelength, fluence and quantum efficiency. Because there is no yet a general EUV ablation theory, data are analyzed in order to underline regularity of the process which can be used in future to detect the scaling laws of the process. The differences with longer wavelengths ablation and EUV one are pointed out and possible applications of EUV ablation are proposed.

Time-integrated spectra and time-resolved spectra (20 ns resolution) of nitrogen discharge plasma radiation were recorded and analyzed. Plasma was created by a 70 kA, 29 ns rise-time current pulse flowing through a 5 mm inner diameter, 224 mm long capillary filled with nitrogen to initial pressure ∼0.1 ÷ 1 kPa. Spectra were captured in the wavelength range 8.3 ÷ 14 nm. This spectral region contains nitrogen Balmer series lines including potentially lasing NVII 2 – 3 transition¹. Spectral lines were identified using the NIST database and the FLY kinetic code. Together with spectra the capillary current was measured. Due to the low inductance design of the driver, the pinch is observable directly from the measured current. 13.38 nm NVII 2 – 3 line was observed in gated, and also in time-integrated spectra for currents <60 kA. For higher gas-filling pressure also other Balmer series lines were observed.

Feasibility measurements leading to the development of a Soft X-ray (SXR) microscopy setup, based on capillary discharge XUV source is presented. Here the Z-pinching plasma is acting as a source of XUV radiation, emitting incoherent radiation in the “water-window” (λ = 2.3 – 4.4 nm) region of interest (natural contrast between the carbon and oxygen edges).This soft X-ray microscopy setup will realize imaging of the biological objects with high spatial resolution. The 2.88 nm radiation line is filtered out from the water-window band, and is focused by an axi-symmetric ellipsoidal mirror, coated with nickle. The focussed spot size is measured and reported. Flux measurements for the available number of photons (photons/pulse) at the sample plane has been carried out with AXUV PIN diode at the sample plane (slightly out of focus). For imaging, a fresnel zone plate lens will be used as an objective. The overall compact transmission SXR microscopy setup design is presented.