Comparison of argon and helium atmospheric pressure plasma jets

Presented here is work on atmospheric pressure plasma jets in helium and argon. The argon plasma jet produces the metastable oxygen states O(¹S) and O(¹D) with emission of the “auroral” green line while the helium plasma jet does not. The electron probability distribution function is investigated with a method based on machine learning using the continuum spectra for both plasma jets. We used schlieren imaging to study plume dynamics and gas shielding effects. The surrounding gas or ambient atmosphere has a profound effect on the argon excimer emission and plasma jet behavior. Plasma parameters were determined from Lissajous plot techniques and BOLSIG+. A detailed comparison of these plasma jets will be presented which offer insight for a variety of technological applications of plasma.