Characterization of Argon Plasma by Use of Optical Emission Spectroscopy and Langmuir Probe Measurements

Abstract

Spectroscopic and Langmuir probe measurements are presented to characterize the argon glow discharge plasma generated by a cost-effective 50 Hz AC power source. Optical emission spectra (400–700 nm) are recorded for different gas flow rates and filling pressures at constant power level. The plasma parameters (electron temperature and density) are deduced from the relative intensities of Ar-I and Ar-II lines. The variation in the intensity ratio of the selected emission lines, electron temperature and density is studied as a function of gas flow rate and filling pressure. Slight increase in the intensity ratio I2(426.62 nm )/I1(404.44 nm ) of the emission lines is observed whereas the electron temperature and density are found to decrease with increase in gas flow rate and filling pressure.