Erosion Model of Trigger Electrode Based on the Theory of Microexplosion

This paper discusses the normal working mechanism of trigatron gap which leads to the erosion of trigger electrode. The theory of microexplosion is based on the gas discharge theory, explosive electron emission theory and thermodynamical theory, and the erosion model of trigger electrode can be obtained by microexplosion theory. The specific action is an important physical quantity in the theory of microexplosion, which could be determined by current density and phase-transition time. The model demonstrates that the erosion of trigger electrode is related to material parameters, discharge current waveform, and charge transfer. Due to the results of experiments, there exists no erosion under the action of trigger current, while under the action of main current, the measured erosion height is 0.51 mm after 4000 shots. Based on the theoretical analysis, it can be calculated that after 4000 shots, the erosion height is 0.54 mm. experimental and numerical results match within 5%.

I. Introduction

Because of low-trigger voltage and simple mechanical structure, the three-electrode trigatron gap with a trigger pin inside the main electrode has been widely utilized in high-power modulators for trigger generators, pulse forming networks, and high-energy pulse power. Most devices require switching of high voltages and large currents at medium repetition rates.