Characterization of Atmospheric Pressure Glow Discharge in Helium Using Langmuir Probe, Emission Spectroscopy, and Discharge Resistivity

The experimental work reported here is a validation of Langmuir probe measurements against emission spectroscopic and discharge resistivity measurements of atmospheric glow discharge plasma parameters. The probe measurements of plasma density are close to that obtained by spectroscopy and discharge resistivity measurement. However, it is found that the electron temperature measurement by the probe is higher than that obtained by the spectroscopic technique. Variation of plasma parameters with operating voltage and frequency, which are estimated by the three techniques, shows a similar trend.