Experiments with plasma opening switch on SNOP-3 generator

Recent experiments with a plasma opening switch (POS) operating in the nanosecond regime applied to a 0.5 TW accelerator are described with different loads (electron or ion diodes, inductive load). The accelerator parameters in negative pulse polarity are 0.7 MV, 0.7-Ω impedance, and 60-ns pulse duration. The POS with 90% transparent squirrel cage, 160-mm diameter anode used a flashboard plasma source installed at a diameter of 320 mm, having 4 sections with 3 rows each of spark gaps. The plasma ion flow density provided 150 A/cm² with 10-15 cm/μs velocity. With inductive load of 15 nH the voltage enhancement reached a factor of 2; the POS impedance was 15 Ω. With the plasma-filled electron diode the voltage amplitude equaled 1.5 MV; the switched current went up to 400 kA; and the load pulse duration measured by pin diode was 20-30 ns. The ion beam generation was realized in a pinch-reflex diode.