Long-Time Evolution of a Low Pressure Laboratory Plasma after Application of Transient high Voltage Positive Pulses

作者：Choudhary M^*; Kar S; Mukherjee S

来源：Contributions to Plasma Physics, 2016, 56(9): 878-888.

DOI：10.1002/ctpp.201500146

• Low pressure plasma
• Electron distribution function
• double hump

The long-time evolution of weakly-collisional plasma with application of high voltage positive pulses to an electrode immersed in plasma, with pulse widths less than as well as more than ion plasma periods, is studied. The plasma is produced by electron impact ionization of argon or helium gas, where electrons are coming out from dc biased hot thoriated tungsten filaments. It is observed that during the temporal evolution of argon plasma, a beam component exists along with temporal bulk electrons giving rise to a double hump profile of transient Electron Distribution EDF). However, in the case of temporal evolution of helium plasma, only a bulk electron population is present. The obtained results are explained by understanding the role played by thermionically emitted electrons during the plasma evolution, the role of the difference of ionization rates of helium and argon, and the higher temporal plasma potential.

• 出版日期2016-10