Experimental studies of a microsecond plasma opening switch in the positive polarity regime

Positive polarity regime of microsecond plasma opening switch (MPOS) was investigated at the DOUBLE generator (480 kV, 300 kA, 1.3 μβ). The measurements of the ion flow parameters showed the considerable enhancement of the ion current density over the thermal flow in the conduction phase. Ion losses reached more than 80% of the full energy losses in MPOS operating on the inductive load. The positive polarity MPOS operation proved to be more critical to the stored current amplitudes and electrode diameters. On one hand, the magnetic field strength should be more than 1 T on the outer cathode surface, on the other hand, the interelectrode gap should be big enough to avoid the secondary plasma influence to the switch performance. The problems of MPOS-diode load coupling are discussed.