Study of plasma evolution in argon-filled capillary Z-pinch devoted to x-ray production

The high-current (up to 40 kA) fast electrical discharge Z-pinch in an argon-filled capillary has been developed to produce pulses of intense soft x-ray radiation in the spectral region of 2-50 nm. We present results of an experimental analysis of plasma evolution in the Z-pinch and discuss them in comparison with a theoretical model. The effects of the electrical circuit parameters and the initial discharge conditions on the plasma evolution are studied. The current was produced by a water dielectric capacitor (C = 3 or 10 nF) resonantly charged to the selected voltages (up to 450 kV) by a six-stage Marx generator. The current pulse with amplitude ranging from 20 to 40 kA and a half-cycle duration of 90 or 170 ns was generated through a 14.5 cm long, 5 mm diameter Al2O3 ceramic channel. The capillary was filled by argon to a selected pressure in the region 0.1-1 Torr. The experimental results are in good agreement with the predictions of the so-called 'simple model of Z-pinch'.