This study aims to investigate experimentally the Ar-He glow-discharge mixture properties using both Langmuir probe and optical emission spectroscopy techniques, at different plasma operation conditions, namely, pressure, applied radio frequency (RF) power, and Helium fraction in the discharge. The plasma is excited in an RF hollow cathode remote discharge system. Different plasma characteristics are studied, such as the electron energy probability function (EEPF), electron density (ne), effective electron temperature (Teff), and atomic lines emission intensities. Findings indicate that the EEPFs exhibit a Druyvesteyn-like shape with depletion of high-energy electrons beyond 50% He fraction. In addition, it is revealed that ne has a maximum at 50% He fraction, which increases with the increase in both total pressure and applied RF power. Regarding Teff behaviors, it is found that it increases with the increase in total pressure, applied power and He fraction. Finally, it is shown that the evolutions of spectral line emission intensities are mainly affected by the applied RF power and partial pressures of argon and helium gases.
S. Saloum (Wed,) studied this question.