Optical emission spectroscopy study of plasma parameters in low-pressure hollow cathode plasma jet and planar magnetron powered by DC and pulsed DC supply

Abstract

Optical emission spectroscopy (OES) has become a non-intrusive and versatile method for plasma parameters determination. Each spectral line in emission spectroscopy corresponds to an optical transition between two quantum levels of atom/molecule. The spectral line intensities are controlled by densities of species in various upper states. We calculated the electron temperature (Te) and electron density (ne) in low-pressure discharge systems based on the modified Boltzmann equation and line intensity ratios. We have evaluated the mentioned plasma parameters in the low-pressure hollow cathode plasma jet (HC) and planar magnetron cathode system (PM) in the continuous DC and the pulsed-DC regime. We present the dependences of the electron temperature (Te) and electron density (ne) on the applied power and the argon flow rate in the mentioned two systems together with a qualitative discussion of the obtained results.