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It is long ago recognized that Z-pinches represent very natural medium for x-ray lasers (XRL) due to its favorable geometry and achievable high densities and temperatures. They also are very efficient x-ray sources. One of their variants, the capillary discharges, attracted attention of plasma physics researchers for almost two decades. It has been used for hot dense plasma formation and x-ray lasers, for transportation of laser beams and XUV radiation generation in x-ray iithography, for basic Z-pinch research and some others. The combination of efficiency, simplicity and low cost of capillary electrical discharges allowed to scale capillary x-ray lasers to table-top dimensions. In this paper we show the modeling results for next, 3-4 times shorter wavelength x-ray lasers. As an efficient x-ray source of line and continuum radiation it can be used for many practically important application in science and technology. In particular, the capillary discharge can appear as powerful potential candidate for emerging XUV microlithography. We present here the results of numerical modeling of spectra and density of Xe EUV source which involved plasma heating and dynamics, detailed atomic kinetics and radiation transport and material ablation physics. [ABSTRACT FROM AUTHOR]

We report new results using the LLNL COMET laser to evaluate the effectiveness of different target architectures to improve the output and characteristics ofthe transient x-ray laser scheme. Surprising observations were found when the laser line focus irradiating a single slab Cr or Fe target was divided into two or three distinct plasma column sections with millimeter scale gaps between each plasma. The Ne-like 3p [SUP1]S[SUB0] → 3s [SUP1]P[SUB1] 28.5 nm and 25.5 nm x-ray laser lines, for Cr and Fe, respectively, were improved in beam divergence, by 2 - 3 times, and peak intensity, by up to one order of magnitude, when compared with a single plasma column of the same length or longer. This was contrary to expectations since these large-scale inhomogeneities introduced along the plasma, as well as attenuation from the cold plasma at the end of each section, would be detrimental to the x-ray propagation and amplification. Instead an injectoramplifier (IA) type process appears to be at work where the plasma gaps may be beneficially modifying the ray propagation and coupling through the high Ne-like ion gain regions. We present results showing the output of the amplifier stage with increasing length for the IA targets together with beam deflection and divergence measurements. [ABSTRACT FROM AUTHOR]

The advantages of using of table top x-ray lasers (XRLs) for different applications have been described. Examples of the first successful use of XRLs, the current efforts in applying them and the potential applications where an XRL can be used in future have been discussed. Modeling results showing the possibility of 3-4 times shorter wavelength capillary discharge x-ray lasers and calculated spectrum of Xe capillary EUV source are presented. [ABSTRACT FROM AUTHOR]

Recent measurements of the K-shell and L-shell x-ray spectra of highly charged heliumlike and neonlike ions are presented that were performed on the Livermore electron beam ion traps and the Princeton tokamaks. These measurements provide new insights into collisional and indirect line formation processes, identifications of forbidden lines, and a new plasma line diagnostic of magnetic field strength. [ABSTRACT FROM AUTHOR]

With the implementation of a transmission-type curved crystal spectrometer at the Livermore high-energy electron beam ion trap (SuperEBIT) the window on sub-eV level measurements of the ground-state quantum electrodynamics and the two-electron quantum electrodynamics of high-Z ions has been opened. High-resolution spectroscopic measurements of the Kα spectra of hydrogenlike Xe[sup 53+] and heliumlike Xe[sup 52+] are presented. The electron-impact excitation cross sections have been determined relative to the radiative recombination cross sections. The electron-impact energy was 112 keV which is about 3.7 times the excitation threshold for the n=2→1 transitions. Although the relative uncertainties of the measured electron-impact excitation cross sections range from about 20% to 50%, significant disagreement between the measured and calculated cross section values has been found for one of the helium-like xenon lines. Overall, the comparison between experiment and theory shows that already for xenon (Z=54) the Breit interaction plays a significant part in the collisional excitation process. The measured cross sections for the hydrogenlike transitions are in good agreement with theoretical predictions. Additionally, the Xe[sup 53+]Ly-α[sub 1] transition energy has been measured utilizing the Kα emission of neutral cesium and barium for calibration. Surprisingly, the experimental result, (31279.2±1.5) eV, disagrees with the widely accepted theoretically predicted value of (31283.77±0.09) eV. However, this disagreement does not (yet) call for any correction in respect to the theoretical values for the transition energies of the hydrogenlike isoelectronic sequence. It rather emphasizes the need for a re-evaluation of the commonly used x-ray wavelengths table for atomic inner-shell transitions, in particular, for the cesium Kα lines. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]