DEVELOPMENT OF 100kV GAP SWITCHES AND GENERATION OF MA-CLASS PULSED CURRENT OF FAST RISING

Abstract

A capacitor bank system for pulsed power use of high current is described. According to a development plan for screw pinch plasma, a medium sized plasma experimental machine TPE-2 was constructed. The specific characteristics for bank system are as follows; the coil current is 1.5_??_4 MA, the pulse duration is 1 ms, the rising time of current is _??_3μ s and the inductance for bank system is the minimized value of a few nH. To realize the required mission for bank system, several components such as a high energy density capacitor, a high voltage co-axial cable, a high current contact were developed. A start gap switch of high performance (fitter time<20 ns at operating voltage=25-80 kV), which was the most important component for realizing the bank system, was developed after the three stages of manufacturing for trial. The machine has been operated for over ten years and the total number of operation becomes 18000, which was near the designed life time of bank system. The start switches have been kept constant in switching characteristics, and the bank system has been stably operated by the assistance of a switch monitoring system.