24 kA solid state switch for plasma discharge experiments

We present the design of a modular, robust, high-current switch for controlling discharge current in the large plasma device ~LAPD! at UCLA. As developed, 10 insulated gate bipolar transistor units are connected in parallel to provide 24 kA current-carrying capacity. Associated snubber and protection circuits are described in detail. The switch is typically operated at a 1 Hz repetition rate, with up to a 2% duty cycle. It has proven to be quite reliable, to date having pulsed approximately 5310 times, with a net throughput of about 2 billion Coulombs. This type of switch not only has an application in such a plasma source, but can also be used to switch large currents for a variety of applications. The design is modular and the switch can be made smaller or larger depending on the desired current rating. © 2004 American Institute of Physics. @DOI: 10.1063/1.1646732#