Optical emission spectroscopy diagnostics for plasma parameters investigation in a Duo-Plasmaline surface-wave sustained discharge

In this study, we used optical emission spectroscopy (OES) as a diagnostic tool in a Duo-Plasmaline surface-wave discharge. Argon plasma emission is recorded in order to calculate the electron density ne and the electron temperature Te in argon gas at a pressure range of 10-30 Pa. To describe argon emission, a corona model using different line ratios is compared to a more complete collisional-radiative model (CRM). It has been found that metastable states play an important role in the population model via electron impact excitation and radiation trapping and should be taken into account for the considered pressure range. The obtained parameters are in the range of 1.4 eV for the electron temperature and 5 × 1016 m-3 for the electron density.