MOS-gated thyristors (MCTs) for repetitive high power switching

Certain applications for pulse power require narrow, high current pulses fo r their implementation. This work was performed to determine if MOS control led thyristors (MCTs) could be used for these applications. The MCTs were t ested as discharge switches in a low inductance circuit delivering 1 mus pu lses at currents between roughly 3 kA and 11kA, single shot and repetitivel y at 1, 10, and 50 Hz, Although up to 9000 switching events could be obtain ed, all the devices failed at some combination of current and repetition ra te, Failure was attributed to termperature increases caused by average powe r dissipated in the thyristor during the switching sequence, A simulation w as performed to confirm that the temperature rise was sufficient to account for failure. Considerable heat sinking, and perhaps a better thermal packa ge, would be required before the MCT could be considered for pulse power ap plications.