Ignitron-Based Switching Scheme for Multiple Ignitron Triggering in Pulsed Power Applications

This paper describes a low-cost ignitron-based switching scheme for transferring energy from capacitor bank to various loads, used in plasma physics and other pulsed power applications. Battery-operated driver modules have been designed to simultaneously trigger two ignitrons in parallel by using either transistor-transistor logic pulses or optical pulses using a fiber-optic interface with optical fibers of length up to 50 m, for applications prone to generate electromagnetic interferences. These driver modules are designed using insulated gate bipolar transistors as switches to deliver a pulse of amplitude of ~500 A and rise time of ~1.2 μs to the ignitor-cathode junction of their respective ignitrons. The modules are designed to facilitate triggering of multiple ignitrons required for large current applications. The feasibility of this scheme and the performance of designed circuit are characterized using a test setup. Statistical variation of triggering delay for single ignitrons is studied extensively, and the effect of trigger energy on statistical parameters is reported. Jitters of 63.5 and 85 ns, respectively, have been observed for triggering of each ignitron used in this scheme. Difference in triggering of two ignitrons connected in parallel is also studied, and a jitter of 150 ns is observed in the onset of current discharges through individual ignitrons.