Gas-puff Z-pinch on pulsed power generator with self-crowbar switch

Abstract

Recent developments in pulsed power technology have increased interest in gas-puff Z-pinches as soft X-ray sources and for nuclear fusion. The pulse width of the pulsed power is extremely short, i.e. several tens of nanosecond, in comparison with the pulse width of the fast bank. Therefore, high current density is necessary to realize pinch phenomena within the pulse width. A self-crowbar switch that can be used to produce a slightly larger pulse has been proposed and tested. Experiments using the LIMAY-1 pulsed power generator are reported. The maximum stored energy, the output voltage, the pulse width, and the characteristic impedance are 13 kJ, 600 kV, 70 ns, and 3 Omega , respectively. The discharge starts at radial positions between 8 and 15 mm, after the Ar gas is injected. Then the pinch of the annular plasma occurs. The cathode and anode configurations have significant effects on the development of a homogeneous annular plasma. The discharges are grouped into four kinds of phenomena: vacuum discharges, Z-pinches without and with self-crowbar switches, and no Z-pinch with self-crowbar switches.<>