Git8 Long Conduction PCS Operation At 5ma Current Level

Abstract

The long conduction POS technology is studied on GIT8 since 1992. The usual type POS with radial plasma injection has demonstrated slow opening into small impedance load simulating z-pinch load conditions. Also in this POS large amount of plasma was pushed by EM force into load region located about 60 cm downstream during 1.3 {mu}s conduction time. To avoid these problems a new POS design was developed called PSIPS (Plasma Switch with Inertial Plasma Stopping). The first PSIPS version was studied on GIT4. The idea is to inject plasma with high initial velocity between coaxial electrodes in direction opposite to that of the EM force. In this case part of the conduction time plasma moves along from the load, then stops and changes the direction of its movement to the opposite one. As a result the total time until plasma is removed from the switch region increases without increasing plasma mass and/or cathode diameter. The PSIPS operation at 40 kV charging voltage on GIT8 has demonstrated improved opening into small impedance load compared to the usual POS with radial injection. With cathode diameter of 160 mm it opens at 2.6 MA peak conduction current at a charge time of 1.3more » {mu}s.« less