Measurement of the electron energy distribution function in an argon radio-frequency discharge in the γ mode

The α–γ transition in an argon radio-frequency discharge has been measured using Langmuir probes and a current–voltage monitor. At two pressures, bi-Maxwellian electron energy distribution functions were measured in the γ mode. Increasing the gas pressure results in a decrease in the high-energy component of the electron energy distribution function. A transition region in the current–voltage characteristic is also observed.