On plasma flow parameters of nanosecond vacuum spark discharge

The plasma flow of a nanosecond vacuum spark was investigated with Faraday cup and MCP (micro channel plate) amplifier. It is shown that the plasma flow consists of high-velocity and low velocity parts. High velocity part of plasma flow has small intensity and contains ions with velocities up to 10⁸ cm/sec. Low velocity part has high intensity and contains ions with velocities up to 3 10⁶cm/sec. High-energy electrons, propagating with the plasma flow, were found. Occurrence of these electrons can be explained by plasma instabilities. The measurement of electron energies was done with retarding potential method. The electron energy makes 100eV for low velocity plasma flow, and more than 1 keV for high velocity plasma flow.