Prediction of the breakdown voltage and breakdown area of gas switches based on ionization integral

Gas spark switches have a simple structure and high current capacity and are widely used in the field of pulsed power. The breakdown path of gas switches affects their jitter and lifetime. Particle simulations are used to analyze the breakdown path, which requires a large amount of computation resources. In this paper, in order to calculate the ionization integral value of electrode gaps, a simulation-based method using a simplified model is studied. The integration of the ionization coefficient along the E-field curves is calculated for the electrode gap and is used to determine if breakdown occurs for a given curve. The breakdown region of two-electrode self-breakdown switches is estimated using the distribution of breakdown curves, and the trigger voltage of a three-electrode gas-trigger switch is estimated by analyzing the curves. By applying the ionization integral value to different paths to reach the streamer formation condition as the breakdown criterion, the operating voltage and erosion region of the electrodes are estimated. The numerical results for an environmental pressure of 0.2 MPa are in good agreement with the experimental results from a triggering experiment that uses a three-electrode gas-triggered switch. This ionization integral model can be used to predict the breakdown voltage and breakdown region of gas switches, which is conducive to improving the performance of gas switches.