Minimum firing voltage characteristics of Triggered Vacuum Gap

Abstract

The low voltage switching characteristics of a triggered vacuum gap has been investigated experimentally in the range 50 to 2, 500 volts.
Specially, the following items have been examined: (1) effect of minimum firing voltage and switching time on the polarity of the main gap voltage; (2) relation between minimum firing voltage and di/dt of main current; and (3) observation of cathode spots by using high-speedstreak camera.
Furthermore, it has been found that the gap could be triggered as low as 50V with switching time 10μs. Minimum firing voltage and switching time are small with a positive main gap voltage than a negative one. Minimum firing voltage and switching time decrease with increasing di/dt of main current. Minimum firing voltage increases when the duration of trigger current is less than 10μs. In the initial stage of discharge, bright cathode spots are observed on the trigger electrode. With the firing on the anode the light emission accompanying the main discharge differs from that for firing on the cathode.