Characterization of a theta-pinch plasma using triple probe diagnostic

Abstract

Plasma diagnostics were carried out in a theta-pinch device to investigate the applicability for plasma–material interaction under fusion-like conditions. A series of triple probe diagnostics show that the plasma is sustained for approximately 80μs at each pulse, with 3.0 (10)21m−3 plasma density and up to 40eV electron temperature when a 32μF main capacitor is discharged at 20kV. In order to increase plasma density and temperature, an RF antenna is installed near one end of a Pyrex tube and a 50μF preionization capacitor is connected to an electrode placed at the same end as the antenna. In this configuration, several time delays between the main and preionization capacitors are tested. When the preionization capacitor was triggered 45μs before the main bank discharge, it resulted in high energetic plasma being obtained with a few density spikes at 1022m−3 and electron temperature around 100eV.