High-Current Plasma Current Opening Switch Powered from Magneto-Cumulative Generator

Summary form given only. Results of an experiment, performed for the first time, on realization of a plasma current channel (PCC) opening in a plasma current opening switch (POS), powered from a current magneto-cumulative generator (MCG) are presented in the paper. To study the POS operation as an energy source we used the helical MCG having an internal stator diameter of 200 mm (MCG-200). The generator MCG-200 with the explosive current opening switch makes it possible to realize the current pulse with an amplitude I_max~4 MA with a rise time of ~1 mus in a load up to 50 nH inductance. In the experiment we installed three gas-plasma injectors with a pulsed gas puff on the outer cylindrical electrode of a plasma chamber. These devices inject plasma jets of 4 cm diameter with an electrons density up to 10¹⁰ cm³ on the injector output into a radial inter-electrode gap of the POS. We used integrated Rogovsky coils to record a value and pulses shape of the current, and differentiating probes to measure a current derivative. In the experiment we used more than 40 recording channels based on analogue and digital oscilloscopes. Analysis of the experimental data showed that all methods agree with each other with the precision of the measurements errors. Critical current of the POS was 1.9plusmn0.1 MA, the current decay time at the breaking moment reaches the value of ~10¹³A/s.