The Pfl “squiggle:” an Independent Monitor of Trigger and Cascade Section Runtimes

The refurbished Z pulsed power driver has been operational since October of 2007 delivering a peak current of ~26 MA to the load. A critical component of the refurbished Z accelerator was the Laser Triggered Gas Switch (LTGS) with a maximum proven operating point of 6.5 MV, 820 kA and an overall 1-σ timing jitter of ~6 ns. We have identified a feature in the V-dot monitor on the Pulse Forming Line (PFL) downstream of the LTGS which is indicative of the closure of the trigger section of the switch. The PFL “squiggle” feature allows us to independently measure the runtime of the cascade and trigger sections and identify problems associated with the laser triggering of the switch, such as poor alignment or degrading transmission of the focusing lens. The squiggle also helps characterize the effect of changes in operating conditions and switch design. For the most recent design version of the LTGS, the trigger and cascade section runtimes with ±1-σ jitter are 0.8 ±1.3 ns and 46 ± 5.3 ns respectively. The trigger and cascade section runtimes are not correlated suggesting that the trigger and cascade sections operate independently of each other.