DC breakdown in low-pressure CF sub(4)

This paper reports the results of studying dc breakdown in low-pressure CF sub(4) gas. We measured the breakdown curves over a broad range of values of CF sub(4) pressure and interelectrode distance L. Two breakdown modes were observed at different CF sub(4) pressures. When the values of the product of gas pressure and gap width are moderate, pL < 2 Torr cm, a balance is achieved between molecular ionization through electron impact and electron escape to the anode and tube walls due to the drift in the electric field and diffusion, respectively, whereas the attachment of free electrons to CF sub(4) molecules does not play any role. At large values, pL > 2 Torr cm, the rate of growth of breakdown voltage with pressure essentially increases because a considerable number of electrons may be attached to gas molecules.