Pseudospark Discharge Behavior at a Low Charging Voltage

Evolution maps of the sputtered copper vapor in the hollow cathode and the main gap areas of two experimental pseudospark switches operating with several buffer gases are obtained with laser-induced fluorescence. The measurements aim to understand the pseudospark breakdown formation and are deliberately made at low charging voltages (1 kV) at which the interval between the trigger pulse and the pseudospark breakdown is characterized with a low current (~10 A) and a long (1-5 mus) randomly variable shot-to-shot duration. Reported are the results for prebreakdown intervals with different lengths. On the other hand, the unfavorable statistical behavior is utilized with the method of the Laue diagrams, which allow phenomenological investigation of the breakdown. In addition, spectrally integrated plasma-emission images taken with an intensified charge-coupled-device camera are represented