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

The properties of the hot spots in Ar and Ne plasma of gas puff z-pinch were investigated. Pinhole cameras with entrance diameter 13--250 μm, XRD, surface-barrier 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 μm) and Ne (40 μm) hot spots were found and K-lines in x-ray spectra were registered. The 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 of electron temperature and density in Ar hot spots Te=1.0--1.1 keV, ne=(1.8--4.0)x1027 m-3, which support the idea of the Bennett equilibrium validity for the spots