Formative Time Lag to Breakdown in Micro Gap at Low Atmospheric Pressure

This paper studies the discharge development in a micro gap between metal materials in air experimentally and analytically. As a high voltage side electrode is stressed by different voltages at a fixed gap length with UV irradiation, the electrical breakdown voltage is measured as a function of the time lag. The measured time lag until the spark breakdown ranges from 10-1 to 10-4 s between 190 Torr and 760Torr. Using the measured time lag to the breakdown, the formative time lag to breakdown is obtained and the formative time lag to breakdown is calculated by gammai, gammap and gammam. The calculation results of the formative time lag agree with the experiment results. The obtained values of gamma i, gammap and gammam are applied to the estimate the formative time lag to breakdown at various pressures, from 190 Torr to 760 Torr, between metal electrodes in a uniform electric field