High-power switch with Sl-thyristors for klystron pulse modulators

To improve the reliability of a line-type modulator for a klystron, we have developed a solid-state switch with Sl-thyristors to replace the thyratron tubes. Fast turn-on characteristics of Sl-thyristor have been studied using a very low-inductance circuit. A maximum current of 10 kA and di/dt of 110 kA//spl mu/s with an anode voltage of 15 kV were obtained. We have designed and built a 45 kV solid-state switch that consists of 15 Sl-thyristors stacked in series. The switch has been successfully operated at 45 kV hold-off voltage, 6,000 A peak current, 6 /spl mu/s pulsewidth and 25 Hz.