Low-pressure discharge with hollow cathode and hollow anode in a trigger unit of pseudospark switch

This paper deals with the investigations of the auxiliary glow discharge in the trigger unit of the pseudospark switch. The trigger unit communicates with the grounded electrode of the main high-voltage gap due to the aperture in the flat part of one of the trigger electrodes. Then, the so-called parasitic current closes to the main electrode via this aperture. This paper is mainly concentrated on the problem of the formation of the parasitic current for different regimes of the auxiliary discharge burning and for different designs of the trigger system. At a low current, the auxiliary discharge burns in the suppressed regime, and an increase in the current results in the stepwise transition to the ordinary glow discharge. The conditions of sustaining the auxiliary discharge influence on the value of the parasitic current. In the experiments, the cavity of the trigger electrode can play a role of the hollow cathode or the hollow anode, so that the negative glow plasma or the positive column plasma is generated in this hollow electrode. It is demonstrated that for both cases, the parasitic current is determined by the ion flow from the plasma boundary.