On the role of electron attachment in the breakdown strength of gaseous dielectrics

Publisher Website
Google Scholar
Abstract
Experimental data on electron attachment and breakdown voltages Vs for two groups of strongly electron attaching gases-perfluorocarbons and freons-and some of their mixtures with electron slowing-down gases have been used in an effort to quantify the role of electron attachment on the breakdown strength of gases. The perfluorocarbons (PFC) considered have positive electron affinities (EAS) and capture electrons at thermal and near-thermal energies principally non-dissociatively. The freons capture slow electrons dissociatively producing mainly Cl-. Vs is strongly influenced by the magnitude and energy dependence of the attachment cross-section, sigma a( epsilon ). The increase in Vs with increasing attachment, however, seems to saturate, indicating an upper limit in Vs of approximately 2.5 times that of SF6. Electron detachment seems to be indicated for PFC and SF6.