Time resolved imaging study of phototriggered discharges in SF6 and Ne/SF6mixtures

The spatial dynamic of phototriggered discharges in SF6 and Ne/SF6 mixtures has been studied through gated intensified charge-coupled device camera me asurements correlated to current and voltage measurements. Physical mechani sms involved in discharge instabilities, which limit performance of dischar ge pumped HF/DF lasers using H-2 or D-2, are under investigation, It is sho wn that the high cathodic emission intensity and the discharge bulk glow ar e separated by a pronounced dark space. Arcs develop at a time which depend s upon parameters such as the SF6 pressure and the current pulse duration.