Development Of Electric Pulse Triggered Gas Spark Switch

Switch is core component in pulsed power technology. Electromagnetic pulse is a very important aspect in which pulsed power technology is applied.Switch in this article is used for electromagnetic pulse simulator which will be used for electromagnetic compatibility test equipment. The coaxial field distortion spark switch developed in this article is a sort of closure gas switch.It is constituted of two main electrodes and a trigger electrode. Before triggered, switch does not discharge when a set voltage is exerted across the two main electrodes. At the trigger threshold, trigger pulse causes strong electric field distortion between trigger electrode and two main electrodes, then the gap quickly discharges, and switch is conducted. The main contents obtained from the researches are listed as following:1. The interrelated basic theory of gas switch was discussed. Gas discharge theory was introduced. Conduction process and influence factors of switch were analyzed. Influence factors of switch discharge current and life expectance were calculated theoretically and discussed.2. Transmission line theory was briefly introduced, includes transmission line distribution parameters including distributing conductance G, distributing inductance L, distributing capacitance C: transmission line equation and its solving process; asymmetry distributing parameter transmission line equation; elementary character parameters of transmission line including character impedance, reflectance, etc.3. The coaxial integrative gas switch that not only has fine shielding effect but also contributes to diminish the pulse rise-time was specifically designed. Breakdown voltage of switch, conduction time and switch inductance were calculated theoretically. Mechanical structure was designed.Eelectric field distribution of switch was simulated.4. The switch designed was experimented and tuned for parameters, including static characteristic and dynamic characteristic of switch. The main experiment conclusion includes:a) Self-breakdown voltage of switch increases linearly with increase of atmospheric pressure.b) Trigger extent is wider when trigger electrode is close to cathodal.c) Trigger extent of negative pulse is wider than positive pulse under same conditions.d) The increase of switch’s work atmospheric pressure could effectively diminish switch’s spark inductance, consequently reduce pulse’s rise-time.e) Capacity of energy reserve capacitance decides energy of pulse, fall-time of output pulse will be delayed about10ns when energy reserve capacitance increases100p.The theory and numerical value result basically fit in with expriment result. A gas spark switch triggered by electric pulse was successfully developed and applied to pulse generator set.