Vacuum switch performance in a 1.2 MJ pulse forming network

Vacuum switching has been used since the early days of pulsed power to provide a means to controlling the flow of large amounts of current. The attractions of vacuum switches for high energy switching are the vacuum mitigates mechanical shock generated by the discharge, low erosion rates, and rapid recovery for repetitive rate operations. Some of the drawbacks of vacuum switching are typically the requirement of a vacuum system and metal vapor sputtering which eventually renders the switch unusable. SAIC has developed a compact vacuum switch which is capable of conducting a current pulse in excess of 300 kA peak for a duration of approximately 0.5 ms. On a single shot, 150 C have been switched while the amount of action seen by these switches has been as much as 3.65x10(7) A2 s. Switches of this design have been able to conduct up to 20 pulses of this magnitude before failure has occurred. The switch is triggerable down to 80 V potential across the anode and cathode. This paper describes the development of this switch.