Investigation of a 0.1 Hz 800 kA LTD stage

A 0.1 Hz, 800 kA LTD stage for the Z-pinch driven fusion-fission hybrid reactor (Z-FFR) has been developed. The stage consists of 34 bricks, which are coupled through 4 matglas magnetic cores. Each brick has two 40 nF/100 kV capacitors and a gas switch of 4 gaps in series, and the loop inductance is 272 nH. The LTD stage can deliver about 800 kA current pulse with a rise time of 100 ns into the matched liquid resistive load with a repetitive frequency of 0.1 Hz. A novel trigger way that only one trigger cable triggers the stage via a continuous trigger bus internal to the stage has been proposed and demonstrated. The experimental results show that the new trigger way is feasible and reliable. A 140 kV, 25 ns rising time trigger pulse and a 5.2 kA, 30 s width pre-magnetization current pulse which can operate with a rep-rate of 0.1 Hz were used in this stage to insure the LTD stage generate a 80 kV/800 kA current pulse every 10 s. A multi-stage gas switch that has a lifetime in excess of 10000 shots and a jitter of less than 3 ns one sigma agrees well with the demand of Z-FFR.