Lifetime and switching characteristics of a high-current multichannel pseudospark

A radial multichannel pseudospark switch is integrated into a plasma focus system designed to generate soft x rays to determine switch durability in a long-term test. The operating parameters correspond to a repetition rate o f up to 2 Hz, stand-off voltages of 10 kV and peak currents of 200 kA. Only minimal electrode erosion is witnessed after a serial test of 180 000 shot s where the electrode surfaces are inspected after every 25 000 shots. The good condition of electrode surfaces suggests the possibility of an additio nal 200 000 shots, implying that for the given parameter range the lifetime of the multichannel pseudospark is at least four times longer than that of traditional high-current switches such as spark gaps. In a comparative tes t the performance of the multichannel pseudospark switch is evaluated again st a multichannel spark gap. The results of these investigations show that the low-erosive pseudospark is well suited to substitute for spark gaps in high-current applications. (C) 1999 American Institute of Physics. [S0021-8 979(99)01524-8].