Experimental and theoretical study of a quasi-steady electron-beam plasma in hot argon

An argon plasma produced by a quasi-steady high-energy electron beam was studied experimentally. The plasma density was measured using an open barrel-shaped microwave cavity. The gas temperature was shown to be a few times higher than room temperature. Electron beam propagation, as well as heat-transfer and kinetic processes in plasma, is modeled self-consistently for the actual experimental conditions. It is shown that the plasma density is largely governed by the conversion rate of the atomic ions into molecular ones. The calculated results are compared to the experimental data.