A 1.1 MV rep-rate in-line output switch and triggering system

An output switch system has been developed for a 100 /spl Omega/ PFN. The output pulse to a matching load has 0.55 MV peak amplitude, with a 1 /spl mu/s pulse width. The PFN is resonant-charged to voltages up to 1.1 MV and operates at rep-rates up to 5 Hz. The switch connects the high-voltage output terminal of the PFN directly to the load. This in-line configuration calls for a trigger generator that is isolated from ground. The trigger generator housing is connected to the high-voltage terminal of the output load and the 250 kV trigger pulse is applied to a trigger electrode on the switch. A high-voltage isolation transformer provides 240 VAC power to the trigger system. The switch consists of multiple series gaps that fire in cascade, each purged with compressed air at 10 SCFM. The trigger generator is a compact transformer-based unit that is command fired from a fiber-optic cable. Measurements of jitter for the complete triggering and switching system indicate a total spread of 20 ns to 30 ns depending on rep-rate.