Final results from the high-current, high-action closing switch test program at Sandia National Laboratories

We tested a variety of high-current closing switches for lifetime and relia bility on a dedicated 2-MJ, 500-kA capacitor bank facility at Sandia Nation al Laboratories, Interest was in a snitch capable of one shot every few min utes, switching a critically damped, de-charged 6.7-mF bank at 24 kV: with a peak current of ol er 500 kA. The desired lifetime is 24 000 shots. Typic al of high-energy systems, particularly multimodule systems, the primary pa rameters of interest related to the switch are 1) reliability, meaning absence of both pre-fires and no-fires; 2) total switch lifetime or number of shots between maintenance; 3) cost, Cost was given lower priority at the evaluation stage because there are unc ertainties in estimating higher-quantity prices of these devices, most of w hich have been supplied before in only small quantities. Cost has more impo rtance in choosing between viable candidates after testing. The categories of switches tested are vacuum discharge, high-pressure discharge, and solid -state. Each group varies in terms of triggering ease, ease-of-maintenance, and tolerance to faults such as excess current and current reversal. We te sted at least two variations of each technology group. The total number of shots on the switch test facility is about 50 000, This paper will present the results from the snitch testing. The observed lifetime of different sni tches varied greatly: the shortest life was one shot; one device was still operating after 6000 shots. On several switches, we measured the voltage dr op during conduction and calculated energy dissipated in the switch; we wil l show these data also.