Electron Swarm Parameters in c-C₄ F₈ and CO₂ Gas Mixtures From Boltzmann Equation Analysis

The electron swarm parameters in c-C4F8/CO2gas mixtures, including the density-normalized effective ionization coefficient (α-η)/Nand the drift velocityVe, are calculated for the overall density-reduced electric-field strengthE/Nvalues from 150 to 600 Td (1 Td = 10-17V · cm2). These calculations have been performed through solving the Boltzmann equation under the two-term approximation in the condition of steady-state Townsend experiment. The c-C4F8contentkin the gas mixtures can be varied over the range of 0%-100 %. From the variation curve of (α-η)/Nwith the c-C4F8mixture ratiok, the limiting field strength (E/N)limfor each c-C4F8concentration is determined for the analysis of the insulation characteristics of the c-C4F8/CO2mixture. Additionally, the global-warming potential and the liquefaction temperature of c-C4F8/CO2gas mixtures are also taken into account to evaluate the possibility of applying in gas insulation of power equipment.