Design, Construction, and Characterization of a 1 kJ Solid-State Switched Pulsed Power System Discharged Through a Coaxial Plasma Gun

With an increased interest in high speed and reliable pulse power switching over the recent years and with the proliferation of semi-conductor manufacturing technologies, the Thyristor or Silicon Controlled Rectifier (SCR) has seen renewed interest for pulse switching. Often however, pulse power system design requires knowing load parameters for correct switch sizing and gate driver design to prevent unwanted thyristor breakdown. This is made difficult when the load is a variable plasma breakdown whose properties itself are dependent on the switch turn-on properties. This poster covers research done on a Thyristor switched pulse power system as operated with a basic coaxial plasma gun (CPG.) The primary components analyzed in this research are: 1.) RLC behavior of the CPG. 2.) Turn-on mechanics of the thyristor switch. 3.) Effect of varying gate driver parameters on switch operation. 4.) Timing of fiber optic signal link to activate the gate driver. 5.) Interrelation between thyristor turn-on profile and CPG operation. This modular pulse power system is rated for 6.5 kV and >1 kJ. The thyristor used has a jitter of under 500 ns and can handle surge currents of over 95 kA. The turn-on time of the CPG discharge is approximately 4 µs with a full 5τ pulse length of ~100 µs. Switch losses are less than 1%. By understanding the relationship between the thyristor and the variable plasma load, better switch designs can be incorporated to increase timing control without sacrificing CPG performance or system safety.