Aachen PK 2003 – scientific programme

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K: Kurzzeitphysik

K 5: Short time-scale physics, posters

K 5.7: Poster

Thursday, March 20, 2003, 17:30–19:15, Foyer

Pulsed power opening switches based on semiconducting devices — •Volker Brommer and Emil Spahn — Deutsch-Franzoesisches Forschungsinstitut Saint-Louis (ISL) Postfach 1260, 79576 Weil am Rhein

For generating electrical high power pulses by utilising magnetic storage systems switching elements which have the ability of conducting and interrupting high current pulses (some kA) are required. Concerning semiconductors thyristors are the most powerful devices. In general, due to their structure, they can be used as closing switches only . However, if the principle of counter-current injection is used, they can be applied as opening switches as well. In this case the forward current of the device is forced under the holding current. Thus the thyristor will turn into the blocking state after a short period of time, the so-called recovery time. As a consequence the current is interrupted. In order to enable a high switching efficiency the recovery time should be as low as possible. At the French-German Research Institute a lot of work has been performed in order to obtain a high turn-off current capability for this thyristor opening switch. The measures and experiments having been made to reach a turn-off current of more than 20 kA will be presented. Besides this systematic investigations for determining the temperature dependence of the recovery time have been carried out. The corresponding results show that cryogenic temperatures drastically decrease the recovery time and in this way enhance the switching efficiency.