Electron and Ion Swarm Parameters in Gas Mixtures of Ar, He with Dry Air by Pulsed Leaser-Induced Plasma Method

We measured electron and ion swarm parameters in gas mixtures of Ar or He with Dry Air at atmospheric pressure. This paper presents the average drift velocity of three kinds of charged particles and the effective ionization coefficient of electrons using two types of gas mixtures: Ar with Dry Air (Ar/Dry Air) and He with Dry Air (He/Dry Air). The Pulsed Laser-induced Plasma method was used in this experiment because this way can measure discharge current easily. Each gas were injected into discharge chamber to total gaseous pressure 760 Torr (1013 hPa) converted by 20 °C. As a result, the average drift velocity of electrons in Ar/Dry Air depended on mixing rate of Ar and changed remarkably at low reduced electrical field: E/P = about 5 ~ 18 V/cm Torr. On the other hand, it showed almost same value in a range of E/P = about 23 ~ 33 V/cm Torr. In case of the average drift velocity of ions, the drift velocity in He/Dry Air was faster than that in Ar/Dry Air at same E/P. Moreover, the drift velocity of positive and negative ions in Ar/Dry Air almost had no effect on injected Ar gas amount. Regarding the effective ionization coefficient of electrons, Ar/Dry Air and He/Dry Air depended on Air concentration. Especially, the critical reduced field strength Ec/P depended on Air concentration, remarkably.