Initiation of explosive emission centers assisted by laser ablation plasma

Abstract

Ignition of explosive electron emission centers (ectons) is a great problem if operating voltages are rather low and vacuum conditions are clean. However, dense enough plasma adjoining directly to the cathode surface promotes new ectons to be ignited. The idea of the present work is an attempt of using laser ablation plasma to stimulate ignition of ectons. For tests, a gap formed by the ring anode and a single-wire cathode was located at the distance of about 1 cm from a target. High-voltage rectangular pulses of the amplitude 25-40 kV and the rise time about 3-4 ns were applied to the cathode synchronously with laser pulses. The paper presents results of experiments that are the ablation plasma parameters near the cathode and the statistics of successful ignition of ectons. As well, theoretical analysis of ecton initiation under actual experimental conditions is made and presented.