Effect of Secondary Ionization Coefficient on the Breakdown Voltage in Nitrogen Gas

Abstract

Abstract A theoretical investigation of the secondary ionization coefficients that responsible for the ionization current growth in uniform electric field studied. Nitrogen gas was from the range of E/p various 60 to 392 V/cm Torr, which corresponding to low values of pressures (0.05 < p < 0.684 Torr). The secondary ionization coefficients have been calculated using the breakdown criterion condition for a discharge gap in a uniform electric field. Using theoretical values of the primary ionization coefficient determined from numerically solving Boltzmann equation together with the values of the sparking distance (ds) obtained from present work. The program provided all cross-sections data from nitrogen. Experimentally, the measurement of breakdown voltage was taken after fixing sparking distance at ds= 69 cm. The results of the present work showed that, the value of breakdown voltage decreased during the increase of the secondary ionization coefficient value. Furthermore, under very low-pressure range, and within the studied sparking distance ds, the value of secondary ionization coefficient was negligible. During pressure increase, the value of secondary ionization coefficient becomes a saturation value.