Analysis of Switch Performance on the Mercury Pulsed-Power Generator

Mercury, Figure 1, is a magnetically-insulated inductive voltage adder that was acquired, assembled, and made operational by the Pulsed Power Physics Branch at the Naval Research Laboratory in Washington, DC^1,2. Mercury is designed to produce a 50-ns pulse of 6-MV peak voltage, and 360-kA peak current when operated at full power. This is accomplished using four, SF₆ filled, laser-triggered switches (LTSs) to transfer energy from four intermediate-storage capacitors to 12 pulse forming lines (PFLs). By discharging the PFLs in a parallel/series configuration via self-break water output switches (OSs) into six induction cells, the output pulse is realized. To achieve optimal power flow, OS closure times should be staggered according to the delay time between adjacent induction cavities³. Consequently, both LTS and OS jitter need to be kept to a minimum. During different stages of assembly, the LTSs and the OSs were tested using dummy loads these tests.