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Soft X-ray emission from nitrogen plasma of a small gas-puff Z-pinch has been studied. Multilayer mirror polychromator with time-resolved registration by PIN diodes was installed and its relatively narrow spectral windows were aligned to the important parts of nitrogen spectrum between 390 and 710 eV. The electron temperature evolution (T(sub e) is approximately equal to 400 eV in hot spots) was measured from a slope of recombination continuum of He-like nitrogen. The T(sub e) of bulk plasma (approximately equal to 100 eV) is compared with T(sub e) calculated from yields of K-shell lines. Moreover, pinhole cameras were used for better understanding the radiation phase of the pinch. Time sequences of peaks in X-ray signals corresponding to a number of bright spots on photographs, are presented.

In this paper, we reveal the feasibility of obtaining laboratory craters to investigate planetary events such as meteorite craters. Experiments were performed by using 0.44-[micro]m laser beam with energy of [less than or equal to] 15 J in 350 ps (full-width at half-maximum) on aluminum targets. We obtain simple and complex craters similar in contour that are formed due to large meteorite impacts on the terrestrial surface. Simulations performed with the 2-D radiation hydrodynamic code MULTI help in understanding the origin of the experimentally observed central uplift of complex craters. Index Terms--Complex craters, laser ablation, laser produced craters, meteorite impact, shock pressure.