Analysis of insulation characteristics of c-C4F8and N2gas mixtures by the Monte Carlo method

The motion of electrons in c-C 4 F 8 and N 2 gas mixtures for a pulsed Townsend discharge is simulated by the Monte Carlo method. The effective ionization coefficient, , over the E / N range from 160 to 480 Td is calculated by employing a set of cross sections available in the literature. From the variation curve of with the C 4 F 8 mixture ratio k , the limiting field of the gas mixture at different gas content is determined. The required gas pressure ratios comparable with the insulation property of SF 6 and GWP at this gas pressure were also investigated. It is found that the insulation characteristics of the N 2 and c-C 4 F 8 gas mixtures are comparable with the N 2 and SF 6 mixture, but the GWP of the former is significantly lower than that of the latter. Simulation results show excellent agreement with experimental data available in the literature.