Negative Ion Formation and Electric Breakdown in Some Halogenated Gases
W. M. Hickam, Dmitry Borisovich Berg · The Journal of Chemical Physics · 1958
Utilizing a conventional electron gun and mass spectrometer, the formation of negative ions at low electron energies have been investigated for a number of halogen containing gases used in electric breakdown studies. The SF6— peak is used as an energy calibration for establishing the appearance potential and the energy width over which capture occurs for the individual gases. It is found that the relative areas of the negative ion curves can be correlated with the electric strength of the gases. The results suggest that the formation of SF5— rather than SF6— may be the important process in providing the relatively high electric breakdown value for SF6. Electron attachment associated with SF6 and CCl4 is found to be an extremely sensitive function of the gas temperature. The gases investigated include CCl4, CCl3F, CCl2F2, CClF3, CF4, CF3SF5, SeF6, C2F3Cl, CHCl2F, CF2Cl–CF2Cl, and ClO3F.