Solid state on-off switches using IGCT technology

This presentation is about semiconductor devices used for On-Off pulse switching applications and used in a 12 kVdc / 3.2kA / 10 Hz solid state switch assembly. The switch assembly is built-up with IGCT (Integrated Gate Controlled Thyristors) and used for long pulse (1.7 ms) Klystron modulators. The design was made in 2002 and successfully implemented in the Tesla Test Facility (TTF) at DESY in Hamburg / Germany. The components and switches are in the position to switch and interrupt safely up to 4 kA. The presentation will inform about the IGCT devices, switch development, construction, production and commissioning of the complete assembly. Also reliability figures will be presented, and the last 4 years of operation have shown that the switches are extremely rugged. Several IGCT switches are in use in pulse modulators built by PPT Puls Plasmatechnik GmbH and this technology has resulted in a breakthrough for solid state switches in modulator applications. By using different silicon diameters for the devices, different current and pulse repetition rates can be achieved. A new improved version of the switch design is under development.