Investigation of Kinetics of Fast Electrons and Parameters of Negative-Glow Plasma in a Low-Pressure Glow Discharge in Helium

Results of numerical investigation of kinetics of fast electrons and parameters of negative-glow plasma in low-pressure glow discharge in helium are presented. It is demonstrated that electron temperature in the negative-glow region is low and equals to a few tenths of an electronvolt. Numerical simulation revealed the formation of narrow peaks in the electron distribution function and the dependence of the differential flux on energy that are related to fast electrons formed in the reactions of Penning ionization. The results of numerical simulation are corroborated by the results of probe diagnostics of plasma. The possibility of determining concentration of excited helium atoms in negative-glow plasma by detection of fast electrons created as a result of reactions of Penning ionization is demonstrated.

Automated summary

The kinetics of fast electrons and parameters of negative-glow plasma in low-pressure glow discharge in helium were investigated numerically. It was found that the electron temperature in the negative-glow region is relatively low, around a few tenths of an electronvolt. Narrow peaks in the electron distribution function and the dependence of the differential flux on energy were observed in the numerical simulation, which is attributed to fast electrons formed in the reactions of Penning ionization. The results of the simulation were confirmed by probe diagnostics of the plasma. It was also demonstrated that the concentration of excited helium atoms in the negative-glow plasma can be determined by detecting fast electrons created as a result of Penning ionization reactions.