Large effects of small pressure changes in the kinetics of low pressure glow discharges

Abstract

Low pressure glow discharges produce cold plasmas, far from thermal equilibrium. Typical electronic temperatures in this kind of plasmas range between 1 and 10 eV, whereas those of the heavier species (neutrals and ions) remain close to room temperature (< 0.1 eV). Cold plasmas are useful for a large number of scientific studies, like spectroscopy of excited levels or kinetics of highly reactive species (radicals and ions), which play a key role in the gas phase chemistry of combustion or in remote regions of interstellar space and planetary ionospheres. Cold plasmas find also widespread application in elemental analysis and in a variety of technological processes, like sputtering, thin film processing, plasma sterilization, and controlled fusion devices, where they are used for wall conditioning and cleaning