Evaluation of a triggered vacuum switch for ETC applications

Historically, power supplies for electro-thermal-chemical (ETC) guns have been capacitive pulse forming networks (PFN). One of the impediments to weaponization of an ETC gun system is that the power supply is too large and heavy to be practical. One of the power supply components which needs improvement is the closing switch. Spark gaps or ignitrons are used in this role. Ignitrons are not well suited for use in a weapon system because of sensitivity to orientation and vibration. Spark gaps are large, heavy, and require periodic maintenance and an auxiliary gas system to operate. The triggered vacuum switch (TVS) offers an alternative to the closing switches used presently. The TVS, developed in the 1960s, was perfected in Russia. The TVS is smaller than spark gaps of similar ratings, and requires no maintenance or auxiliary gas system to support operation. United Defense performed a series of tests to evaluate the TVS for use in ETC applications. We subjected a single switch to more than 90 discharges, including single discharges up to 100 kA peak current and 100 C transferred charge. We also performed five bursts, each consisting of eight 50 kA peak, 50 C discharges. Our results show that the switch performance may be extrapolated to ETC application levels, and that the TVS offers an attractive alternative to existing closing switch technologies.