Evaluation of hot spots parameters by simple soft x-ray diagnostics

Properties of the hot spots in Ar and Ne plasma of a gas-puff z-pinch were investigated. Pinhole cameras with entrance diameter 13–250 m, XRD, semiconductor detectors and flat crystal spectrographs with Si and KAP crystals were used for spatially, temporally and spectrally resolved soft x-ray diagnostics. The diameters of Ar (25–30 m) and Ne (40 um) hot spots were found and K-shell x-ray spectra were registered. Temporal evolution of x-rays within 600 ns was observed; the upper estimate of hot spots lifetime did not exceed 50 ns. The described processing and curve fitting of He-like Ar XVII lines provided the values the of electron temperature and density in Ar hot spotsT_e=1·0–1·1 keV,n_e=(1·8–4·0)×10²⁷ m^–3, which support the idea of the Bennett equilibrium validity for the spots.Reprinted with permission of American Institute of Physics from Dense Z-pinches, AIP Conf. Proc. 195 (Eds. N. R. Pereira, J. Davis, N. Rostoker), AIP, New York, 1989.