The investigation of the left branch Paschen curve under nonuniform field condition

For the development of vacuum interrupters and electron guns it is required that the discharge phenomena in low and medium vacuum be analyzed, in particular, under nonuniform electric field. In this report, the Monte Carlo technique has been used for computer simulation of nonlocal electron ionization in nonuniform electric field. A discharge ignition voltage has been computed for standard discharge gaps. The calculations are performed for several values of ratio electrode curvature radius and gap lengths. The data under such conditions are very important for insulation design of high power vacuum apparatus. Based on the analysis of computing results, the dependence of the discharge ignition voltage and the product gas density and gap length under nonuniform field conditions was clarified and compared with known experimental data. The bending from similar law for nonuniform gap has been investigated quantitatively. It was shown that nonlocal ionization by runaway electrons plays a critical role for similar low irregularity.