The Role of Gas Medium Pre-Ionization in Optimizing Discharge Ignition in a Ring Laser

Abstract

This paper addresses the problem of ensuring reliable ignition of the gas discharge in ring lasers. The transition to a three-electrode ignition system, driven by requirements for energy efficiency and thermal stability, significantly complicates the conditions for initiating the discharge in narrow gas-discharge channels. Optical illumination of the resonator is considered as the primary means of improving ignition reliability. Experimental results are presented on the influence of radiation power, ambient temperature, mounting position of the LED module, and spectral composition of the radiation on the breakdown time and breakdown voltage of the gas-discharge gaps. It is shown that the key mechanism for generating seed electrons is photoemission from the dielectric walls of the sitall channel, rather than from the cathode surface. The minimum illumination parameters that guarantee stable ignition over the entire operating temperature range (from -55 °C to +75 °C) are determined. It is found that using blue light reduces the breakdown voltage by 20-25% compared to yellow light. Practical recommendations are given for optimising the illumination system to improve operational reliability and reduce power consumption.