The electrostatic plasma injection switch (EPIS)

A new type of switch called electrostatic plasma injection switch (EPIS) is developed which uses transmission line reflections of incoming trigger pulse to generate voltage gradients on a multisection hollow trigger pin that extends from cathode into a hollow anode. Low current preionization at the bottom of cathode region provides free electrons for fast turn on. The voltage gradient on the trigger pin injects triggering plasma into the region between anode and cathode, thus initiates a high current hollow cathode discharge. This switch operates in the left hand side of Pachen curve as thyratron and pseudospark, but should provide better trigger reliability and higher current capability. The EPIS has been operated at 16.6 KV hold off voltage and 4.96 KA with 0.095 Torr of hydrogen. Hold off voltage is limited by local field emission, and a pseudospark like plasma is responsible for the high current capability. This device is operational and waveforms of anode voltage, anode current, trigger voltage, and spectral emission are recorded.