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X-ray reflectivity curves at 20 keV photon energy of alpha-quartz spherically curved crystals have been measured using a micrometric synchrotron beam at the ESRF BM5. Six thin quartz crystals samples with curvature radii of 150 and 250 mm have been studied. Experimental results are compared with diffraction profile calculations using a lamellar model and a good agreement is found.

A plasma of argon produced with a plasma focus discharge has been observed between 3.8 and 4.2 A. Spectra registered with a spectral resolution of 0.03 A/mm show satellite lines of Ar which were measured and compared with two independent theoretical calculations. Seven transitions of Li-like, eleven of Be-like. twelve of B-like, twenty of C-like, nine of N-like, seven of O-like and two of F-like argon have been identified. The agreement between the observations and the calculations and also between the two sets of calculations is generally good.

The combination of a table-top laser produced plasma X-ray source and a spherically bent crystal for the soft X-ray region is used in traditional X-ray microscopy schemes. The X-ray source is well localized both spatially ( ~ 20µm) and temporally ( ~ 1ps) and is spectrally tunable in a relatively wide range (6–14A). High quality monochromatic (δλ/λ ~ 10-5–10-4) images with high spatial resolution (up to ~ 4µm) and in a large field of view (few mm) are presented. For many applications, this low-cost compact system can offer a simple alternative to the larger installations, which are usually used. The spherically bent crystals can be used in a wide range of reflection angles, thus allowing wavelength selection.

Spherically curved crystal spectrometers are demonstrated for use on an Electron Beam Ion Trap (EBIT) for the first time. Such spectrometers are characterized by high light collection efficiency and relative insensitivity to source position, simultaneously, giving them an advantage that no X-ray spectrometer previously used on an EBIT has had. One of the spectrometer crystals tested is composed of mica, giving it the additional advantage that it can be used with reasonable efficiency up to very high order, allowing spectra to span a broad wavelength range from 0.5 Angstroms to 20 Angstroms. Spectra from Ne-like barium and He-like argon are presented.

Essential parameters for the application of crystals to quantitative X-ray spectroscopy are the upper wavelength limit and the quantitative reflection properties (intrinsic resolving power, luminosity) of the crystal. Due to the large lattice constant, muscovite, a mica group mineral, can be used in the wavelength range up to about 2nm. Muscovite crystals can be bent to small radii of curvature due to their favourable cleavage and elastic properties. Characteristic reflection properties at reflections 002 – 00 24 were investigated theoretically and experimentally. The integrated reflectivity was calculated for various reflections of perfect flat as well as spherically bent muscovite crystals with curvature radii R = 100 and R = 186mm. It was measured for flat crystals in the reflections 00 10 – 00 26 using CuKα- and MoKα-radiation from X-ray tubes and compared with calculations for both perfect and mosaic crystals. Available high-quality muscovite crystals have a mosaic structure with a mosaic spread of about 1 arcmin. This mosaic spread limits the spectral resolving power for high reflection orders.

The properties of a monochromatic x-ray backlighting system based on a spherically bent crystal were investigated. Simulations of spatial resolution for spherically bent crystals with different radius of curvature and for several wavelengths of incidence radiation were done using the ray-tracing method. Test experiments were carried out to demonstrate the high spatial resolution using the incoherent soft x-ray radiation produced by laser- and x-pinch plasmas. Both experimental and theoretical results show that a spatial resolution of at least 4 μm can be obtained in a field of view ranging from a few mm to cm. The narrow spectral band of the diffracted beam (Δλ/λ ~ 3 × 10−4), the high efficiency of the presented scheme and the possibility of significantly reducing the self radiation of the studied object make it one of the most promising backlighting systems. This scheme permits the essential reduction of requirements of the source of radiation and could be a less costly alternative to using x-ray lasers for such purposes.

We present a detailed analysis of the spectrum of satellite transitions to the n = 23 and n = 2–4 Ne-like yttrium resonance lines. Satellite lines from the double excited 2s22p53l3l', 2s22p53l4l', 2s2p63l3l' and 2s2p63l4l' levels of Na-like Y as well as from 2s22p53l3l'3l" and 2s2p63l3l'3l" levels of Mg-like Y were observed in spectra from a laser-produced plasma. The x-ray spectra were recorded with high spectral resolution λ/Δλ ≈ 3500–5000 in the wavelength region of the n = 2–3 Ne-like resonance lines and with λ/Δλ > 1000 in the region of the n = 2–4 Ne-like resonance lines. A total of more than 50 spectral features were identified, and their wavelengths were measured. A simple intensity model was developed, which agreed well with the measured spectra and assisted the line identification. The consistency of the model for different spectral regions demonstrates the potential of the Na-like and Mg-like satellite lines for diagnosing plasma conditions.

Aluminum wire X-pinch experiments performed at the Cornell University XP pulsed power generator show detailed high resolution spectra for satellite lines of Li-like, Be-like, B-like and C-like ions. These lines, which correspond to transitions originating from autoionizing levels, are observed in the direction of the anode with respect to the hot X-pinch cross point. The intensities of such satellites are much smaller or absent in the direction of the cathode. These transitions are caused by collisions of ions with energetic electrons (5-15 keV) which are created by inductance between the hot spot and the anode. A collisional-radiative model was constructed using a non-Maxwellian electron energy distribution consisting of a thermal Maxwellian part plus a Gaussian part to represent the high energy electron beam. The shapes of the observed satellite structures are consistent with the calculated spectrum for electron temperatures between 30-100 eV, and beam densities of about 10−7 times the plasma electron density.

A dense jet of a plasma consisting of multiply charged ions was generated in the interaction of a laser plasma with a strong external axial magnetic field. It is shown that using the high-luminosity x-ray spectroheliograph technique allows to measure plasma emission spectra with 2-dimensional spatial resolution even in the cases when these spectra have small intensities. The x-ray spectroscopy and interferometry methods are used to measure plasma parameter distributions. The dependencies of Ne(z) and Te(z) measured in this paper can be used to calculate the evolution of plasma ionization state during plasma expansion. The quasihomogeneous laser jet, which appears when a laser plasma interacts with an external magnetic field can be used not only to form an active medium of a short wavelength laser, but probably also to tackle the urgent problem of transport in a laser ion injector.

X-ray spectroscopic methods were used to investigate the spatial distribution of Z-pinch plasma parameters. Experiments were carried out on the GAEL pulse line generator in Ecole Polytechnique (France) with different types of load. Obtained results for the concentration of electrons and plasma temperature showed that higher plasma homogeneity was obtained in experiments with complex load. Spectrograms demonstrate the stabilization effect of the Al-jet.

X-ray spectroscopy methods are used to study the evolution of the ion abundancies in a laser-produced aluminium plasma during its expansion. Plasma parameters are defined with the help of intensities and lineshapes of 3p → 1s and 1snp → 1s2 (n = 6-10) spectral lines of H-like and He-like A1 XIII, XII ions. It is shown that the most strong variation of ion abundances occurs in the plasma regions close enough to the target surface. Mass-spectrometry methods are applied to investigate the amount of ions with different charges at large (≥3000mm) distances from the target.

A superdense X-pinch plasma was used to investigate the emission spectra of multicharged molybdenum ions in the spectral region 4.4 – 5.0 A. A comparison of the experimental data obtained with results of theoretical calculations allowed the identification of a number of spectral lines caused by radiative decay of autoionizing levels of Na- and Mg-like ions. The wavelengths of the identified spectral lines were measured with a relative accuracy of about ±0.001 A. These measurements provide important tests of radiative emission models of dense plasmas.

Investigations of X-pinch plasma structure and generation of an accelerated electron beam in the X-pinch using the methods of x-ray emission spectroscopy are discussed. The diagnostics allowed to make an investigation of the x-ray radiation with high spectral and spatial resolution over the spectral range 0.5 to more than 10 A from a variety of wire materials.

A 100 ns excimer laser-produced copper plasma was used to investigate the Na-like Cu XIX n = 4-2 satellite emission in a higher density and lower temperature regime than previously studied. Theoretical model calculations were used to identify a number of radiative transitions from autoionizing Na-like copper levels. These transitions were measured with an accuracy of 0.001 A. A comparison of these spectral measurements to spectra obtained from lower density Nd-glass laser-produced copper plsmas demonstrated the changing role of different excitation mechanisms for different plasma conditions.

X-ray spectroscopy with high spectral (up to Δλ/λ = 10−4) and spatial resolution (up to 1 μm) is discussed. Devices based on crystals, diffraction and Bragg-Fresnel elements and their applications in Z- and X-pinches and laser plasma experiments are described.

We present an analysis of dielectronic satellite spectra of 2p6-2s2p63p Ne-like krypton resonance lines. The satellite structure was registered with high (better than ?/?? > 3500) spectral resolution in the emission of a laser irradiated gas puff target. We perform an unambiguous identification of satellite lines caused by radiative transitions from autoionizing states of sodium-like krypton ions. A total of about 20 spectral features are identified, most of them for the first time. Very good agreement between the satellite structure calculations and experimental emission spectra is obtained.

We present an analysis of dielectronic satellite spectra of Ne-like ion resonance lines for elements from Cr to Ni. For these low-Z elements, we use spectra from strongly underionized CO2-laser produced plasma to minimize the emission from open L-shell ions. This simplifies the spectra and allows the identification of satellite lines caused by radiative transitions from autoionizing states of sodium like ions. Good agreement between the satellite structure calculations and the experimental emission spectra is obtained.

Spectra with spectral resolution λ/Δλ 3000-7000 in the vicinity of the He-like ion resonance lines Mg, Al, Si, P, S were obtained in CO2 laser-produced plasma. The wavelengths of these satellites were measured and compared with numerical calculations. Identification of lines or a group of overlapping lines was performed. Twenty-two transitions of dielectronic satellites for Be-like ions, 41 transitions for B-like, 40 transitions for C-like, 22 transitions for N-like, 12 transitions for O-like ions and 2 transitions for F-like ions were identified. The average between theoretical and experimental wavelengths was ±(0.0005-0.001)A, but in some cases it was ±(0.002-0.003)A.

Spectra of rare earth elements emitted from ultra short pulse laser produced plasma were recorded using simultaneously high and low resolution, spectrometers. A study of the broad band emission of the Δn = 1 transitions in highly ionized Ba and Sm plasma showed that this band is completely unresolved. The spectra were analyzed using the LTE based on super-transition array (STA) model. The theory reconstructs the entire Ba spectrum using a single temperature and density, whereas for Sm the discrepancies between the theory and experiment are not reconcilable. The agreement in the Ba case is attributed to the fact that BaF2 target is transparent to the laser's prepulse effects, producing a homogeneous dense plasma, whereas for Sm the dilute plasma created by the prepulse is far from LTE. The obtained results posses a significant implication to the applicability of the STA model, in particular for calculations of opacities and conversion of laser light to x-rays.

We demonstrate a simple technique of formation of high intensity collimated x-ray beams. A parallel beam of x-rays was obtained using a table-top laser system and a spherical crystal mirror. The beam is characterized by a high degree of collimation (divergence < 1 mrad divergence) and monochromaticity (Δλ/λ = 7.6 × 10−3). The spectral range produced can be easily tuned using an adequate target material.

A linear zone plate surface structure was created on the surface of mica crystal and used for obtaining spectrally resolved images of 120 fs laser-produced plasma. A linear Fresnel zone structure was optimized on a wavelength λ = 9.16 A and has a focal length of f = 5 cm, minimum zone width Δzn = 300 nm, total length l = 10 cm, total width of zone plate 2rn = 122.6 μm. Images of laser-produced plasma in the spectral range 9.12−9.31 A were obtained. For high Z (Lanthanum) element target the size of the x-ray radiation spot was not more than 20 μm.

The use of the FSSR mica spherical crystal spectrograph with CCD detector to study satellite structures of 1s2–1s2p transitions of [He]-like Al ions and fine structure of Kα-lines is presented. It is shown that the FSSR spectrograph is more suitable for study of laser plasma with high spectral and spatial resolution than other types of spectrographs and the use of this spectrograph gives the possibility to measure the sizes of the x-ray sources and the intensity of the dielectronic satellites.

A study is made of the spectra produced from a short-wavelength long-pulse (nanosecond) laser incident on a Mg plasma. A very complex experimental spectrum is analyzed in detail by comparison with large-scale atomic kinetics calculations using the recently developed mixed-UTA (MUTA) model. We find that the experimental spectrum appears to contain lines from many inner-shell transitions from ions ranging from neutral Mg to Li-like Mg. Lines from transitions such as 1s?3l, 1s?4l, and from hollow atoms (where in this context hollow atoms refer to ions with an empty 1s shell) are observed. The inclusion of very small fractions of hot electrons is demonstrated to make significant differences to the spectra. Although it is found that the calculations do not match perfectly the experimental spectra, reasonable agreement between the experiment and the theory can be obtained if temperature and density gradients are assumed present in the experimental conditions.

Dielectronic satellite spectra near the He-like resonance line W are investigated experimentally and theoretically. We propose that under certain plasma conditions the resonance line structure plays a minor role and can be mixed with the accumulation of Rydberg satellites.

Laser satellites, i.e. spectral lines caused by non-linear interaction of strong laser radiation with multicharged ions, are observed for the first time. Their identification are carried out by comparison of both experimental wavelengths and intensities with theoretical ones. It is shown that observation of laser satellites allows to measure directly the energies of ionic metastable states.

The application of recently developed spectroscopic instruments in laser produced plasmas with simultaneous high spectral and spatial resolution combined with high luminosity discovered new types of x-ray spectra. These new types are characterised by the disappearance of the resonance lines and the strong emission of dielectronic satellite spectra. Several types of transitions of highly charged ions are discovered which are unknown from usual sources employed in atomic physics. New theoretical models are developed and successfully applied for the interpretation and for plasma diagnostics.

The interaction of heavy ion beams and laser light with matter is of central importance for the inertial fusion and x-ray laser research. Recently developed techniques in x-ray spectroscopy have provided extremely unusual emission spectra near the target even in traditional experiments. It will be shown that reasonable interpretation and diagnostic can be achieved only incorporating new concepts in the dielectronic satellite line formation. Theoretical models are developed which provide good agreement with experimental results. Charge exchange processes are proposed for the formation of hollow atoms.