Measurements and calculations of the resonance between the Ly-a line of magnesium and the 2s~3p transition in neonlike germanium are presented. This resonance is of possible use as part of a resonantly photo-pumped x-ray laser scheme recently proposed which would lase on several 2p~2 s transitions be-0 tween 64 and 89 A in neonlike germanium. Measurements of the resonance are made by three different approaches: one using the electron beam ion trap, the second using laser-produced plasma, and the third on a tokamak. These results are compared with calculations and other measurements.Certain discrepancies are observed with previous measurements which may be due to the partial overlap between oxygenlike and neonlike lines in germanium. The results do show a good resonance between magnesium and germanium, with the germanium line between the two Ly-a components of magnesium but nearer to the short-wavelength component.PACS number(s): 32.30. Rj, 42.60.By

This paper presents the results of temporal measurements of the soft X-ray radiation intensity in the spectral range of 10-40 eV emitted from the capillary plasma under discharge with a current pulse of 26 kA amplitude and rising rate of about 10 12 A/s. The experiments were carried out on a pulsed-power facility SIGNAL with ceramic capillaries of 0.3 cm inner diameter and 15.7 cm length, which are filled with argon up to pressures in the range of 0.25-0.5 torr. To interpret the experimental results, a sequence of numerical calculations simulating gas dynamics and level-by-level ionic kinetics of argon plasma was used. The effect of X-ray lasing in the Ne-like line was found to be generated with a quanta energy of 26.4 eV, which lasted for approximately 1-2 ns, at a moment of about 33 ns after the current pulse start.Index Terms-Capillary discharge, multicharged plasma, pulsed-power facility, X-ray laser.

We present the results of X-ray diagnostics of Z-pinch hot points, formed during fast electrical discharges through exploding Al wires. Experimental data include the pinhole images and X-ray time integrated radiation spectra. These spectra were obtained with high spectral resolution in the range 1.5–2.2 keV, contained the most intensive resonance lines of Al H- and He-like ions. Comparison of the recorded lines width and peak intensities with the corresponding modeled values, enables us to estimate the main hydrodynamical parameters of hot point, such as average temperature and density, being achieved at a moment of its maximum compression. Additionally, on the base of theoretical analysis of the spectral intensities distribution in well-resolved Lyα satellites, the gradient of compression velocities field is concluded. Some features of the investigated lines spectra forming are discussed.

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A review of theoretical works on the laboratory X-ray laser (XRL) research performed at RFNC -VNIITF for the last few years is presented. Three potential photopumped XRL schemes with relatively short laser wavelengths (44, 23, and 64 A) have been investigated. Theoretical studies of lasing plasma parameters for some of the published recombination and resonantly photopumped XRL schemes have been performed using our kinetics and line-profile codes.