[en] The method allows to produce robust X-ray focusing crystal structural elements for X-ray spectroscopy, X-ray diffraction, and X-ray microscopy or X-ray astronomy devices. With the aid of mechanical, pneumatic or hydraulic forces crystal discs are given the required curvature which is fixed by coating the convex back of the disc with a curing or thermoplastic adhesive

[en] Subject of the invention is a device for producing X-ray focusing crystal elements to be used in various type of X-ray machines. The device allows to bend thin crystal discs into the necessary form

[en] X-ray spectroscopical and microscopical methods are used for the determination of the spectral and spatial distribution of X-ray intensity of laser-produced plasmas. It is possible to adapt, in the X-ray microscope, the distances, magnification, position, and width of the spectral window to the special conditions of the laser facility. Manufacturing and testing of the two-dimensionally bent crystals requires a great deal of effort. It was demonstrated that a spatial resolution of about 5 μm was achieved, and that the experimentally determined reflectivity was found to be in close agreement with the dynamical theory of X-ray interferences. Due to high luminosity of the X-ray microscope, in experiments with laser-produced plasmas it was necessary to attenuate the radiation with aperture-limiting diaphragms or filters down to 0.01-1% of the original intensity in the case of a magnification of about one. Emission of the resonance line W 1-2, the intercombination line of helium-like ions, and Lyman alpha line were imaged simultaneously with a three-channel microscope. Such images form the foundation for establishing the N_e(r), Tzub(z)(r) maps. (author)

[en] Recent theoretical and experimental research with short-pulse, high-intensity lasers is surveyed with particular emphasis on new physical processes that occur in interactions with low-and high-density plasmas. Basic models of femtosecond laser-solid interaction are described including collisional absorption, transport, hydrodynamics, fast electron and hard x-ray generation, together with recently predicted phenomena at extreme intensities, such as gigagauss magnetic fields and induced transparency. New developments in the complementary field of nonlinear propagation in ionized gases are reviewed, including field ionization, relativistic self-focusing, wakefield generation and scattering instabilities. Applications in the areas of x-ray generation for medical and biological imaging, new coherent light sources, nonlinear wave guiding and particle acceleration are also examined. (author)

[en] For monochromatic imaging applications the advantages of combining two bent crystals in one system are demonstrated in comparison to a single crystal. The investigation shows that considerable improvements in resolution and spectral selectivity can be achieved by successive reflections from two bent crystals. The x-ray imaging device can be designed to a compact optical device mounted with the detector to a single port of the experimental chamber. This type of arrangement is of particular interest to large laser facilities such as those at LLNL, ILE and CEA where a high X-ray photon flux is available but the space available for diagnostics is restricted. A design for an experimental setup planned for imaging of indirect driven fusion experiments at Lawrence Livermore National Laboratory will be discussed here as an example. In general, improvements of spatial resolution by a factor of about 4 and spectral selectivity by a factor of about 10 can be achieved

[en] Detailed spectroscopic analysis of K-shell emission simultaneously observed at the irradiated and unirradiated surface of laser-exploded foils is reported. The space-dependent spectral line widths and relative shifts in the positions of the Al Lyman transition are interpreted in terms of the plasma density variations; the trend in the shifts data supports the idea of a density-dependent line shift. The significant features of the spectra emitted from the densest part of the plasma are compared with predictions from standard diagnostics modeling based on codes MEDUSA and FLY, and with the results of 2D ATLANT hydrodynamic simulations post-processed with a novel suite of atomic physics codes XEPAP. The results obtained corroborate the feasibility of the plasma density diagnostics based on line shifts in the intermediately coupled plasmas

[en] Laser generated plasmas have good prospects as X-ray sources for time-resolved diffraction experiments in solid state research because of the large number of X-ray photons which will be emitted per unit solid angle and wavelength interval. A modified two-crystal diffractometer will be described, which uses the particular advantages of laser plasmas as X-ray flash sources. Requirements for the source will be determined and discussed. (author)

[en] This paper describes a new method for the simultaneous measurement of the integrated reflectivity of a crystal for multiple orders of reflection at a predefined Bragg angle. The technique is demonstrated with a mica crystal for Bragg angles of 43^o, 47^o, and 50^o. The measured integrated reflectivity for Bragg reflections up to the 24th order is compared with new theoretical predictions, which are also presented in this paper

[en] Theoretical investigations for obtaining x-ray point focusing by using crystals with two-dimensionally modulated surfaces are carried out. Based on the Bragg and Fresnel diffraction principles, formulae of modulated surfaces (structures) are derived for both flat and bent crystals for focusing x-rays to micron or submicron size. It is found that elliptically-shaped and linearly modulated structures are suitable for flat and cylindrically bent crystals, respectively. For the given Ti Kα radiation and geometric parameters, Si(111) and InSb(111) reflections are used for the calculations of flat and bent crystals in terms of their focus characteristics, namely the focusing efficiency and the focus width. The influence of the distribution of the Bragg amplitude on flat and bent crystals is also discussed

[en] By the use of a thin highly oriented pyrolytic graphite crystal (HOPG) bent to a high-performance ellipsoidal shape it was possible to focus monochromatic x-rays of 4.5 keV photon energy with an efficiency of 0.0033, which is 30 times larger than for previously used bent crystals. Isotropic TiK_alpha radiation of a 150 μm source was focused onto a 450 μm spot. The size of the focal spot can be explained by broadening due to the mosaic crystal rocking curve. The rocking curve width (FWHM) of the thin graphite foil was determined to 0.11 deg. . The estimated temporal broadening of an ultrashort Kalpha pulse by the crystal is not larger than 300 fs. These properties make the x-ray optic very attractive for ultrafast time-resolved x-ray measurements