Pressure waves generated in a Grimm-type pulsed glow discharge source and their influence on discharge parameters

Gas pressure waves in both argon and helium direct current (dc) pulsed glow discharge (PGD) in a Grimm-type source were found and studied with an inserted microphone. First and second harmonics of pressure vibrations were found to be in good agreement with the resonant frequency (2.7 kHz) of the discharge cell. Formation of the gas pressure wave takes place during about 150 s in edges of PGD. Significant influence of pressure changes on the plasma parameters such as electrical current and optical emission was found. Possible mechanisms responsible for the generation of pressure waves are discussed. In future studies, the results presented here should be taken into account, e.g. for discharge optimization, diagnostics, plasma simulations and corresponding plasma-analytical setups.