Design and operation of a quasi-steady, inverse-pinch-discharge closing-switch

An inverse-pinch discharge is used as a closing-switch for the 1.7 MJ Godzilla pulseline. Gas pulsed into an electrode gap initially in vacuum allows the breakdown voltage to drop below the applied voltage. Connections to the electrodes are coaxial, with the inner connection extending further than the outer. Current flow therefore creates an electromagnetic force on the plasma discharge that is radially outward, an arrangement known as an inverse pinch. Static tests demonstrate the ability of the switch to hold off at least 10 kV for charging times exceeding 20 minutes, and to break down for charging voltages less than 500 V when the shock-tube diaphragm is ruptured. In tests to date, peak currents through the switch have exceeded 340 kA, with a total charge transfer of 540 C.