Design and construction of a ±100 kV gas switch for linear transformer drivers

The design, installation, and performance of a ±100 kV gas switch for linear-transformer-driver (LTD) are presented. LTD demands require gas switches that can be operated at a 200 kV DC voltage, and require trigger jitter and inductance as small as possible. A field distortion switch has been designed based on the L3 switch, the design criteria of switch electric field and trigger system are explained in detail. A two dimensional plasma model is developed to analyze the contribution of trigger system to the closing of gas switch. An experimental platform was built to test the self breakdown and triggered breakdown characteristics of the switch. When the switch is charged to ±100 kV and is triggered by a -120 kV pulse with a 30 ns rise time, the delay time is 78 ns and the jitter is 1.6 ns. A comparative test was done to research the function of UV preionization gap, the test results shown that the UV preionization gap can reduce the switch delay time and jitter, it can effectively improve the trigger performance of the switch. Meanwhile, using the short-circuit discharge, the inductance and impedance were measured, the switch inductance is about 30 nH, and the impedance is varied from 50mΩ to 30mΩ.