40 kV/5 kA Sealed-off Pseudospark Switch

A double gap sealed-off 40 kV/5 kA pseudospark switch (PSS) was assembled and leak tested as shown in Fig. 1. Vacuum processing of the PSS was completed. It has been holding ultra high vacuum better than ~10-8 mbar in the processing station. Conditioning was carried out for an individual gap and for double gap assembly of the PSS. The hold-off voltage characteristics of the individual gap have been tested up to 30 kV in a vacuum as well as in hydrogen gas (pressure: 25 Pa). The hold-off voltage for the PSS was tested up to 52 kV in both vacuum and hydrogen gas environment (pressure: 25 Pa). A switching circuit was made for testing the PSS. Initial switching of the PSS was tested up to 36 kV of the applied voltage in a single


Fig. 1: 40kV/5kA sealed-off PSS

shot operation experiment at working hydrogen gas pressure of 30 Pa. Fig. 2 shows the V-I characteristics of the switch. The initial switching parameters of the PSS were as follows:

  • Applied Voltage: 35.4 kV
  • Anode Current: ~7 kA
  • Voltage fall time: ~50 ns
  • Current rise time: ~350 ns
  • Rate of current rise: ~2×1010 A/s
  • Pulse width (FWHM): 1.5 μs


Fig. 2: V-I characteristics of the PSS