Gas temperature and air fraction diagnosis of helium cold atmospheric plasmas by means of atomic emission lines

• DOI: 10.1016/j.sab.2022.106437
• Publication Date: 2022-05-07T15:14:53Z
• Authors: M.C. García; C. Yubero; A. Rodero
• Keywords: Gas temperature; 0103 physical sciences; Cold atmospheric plasma; Atmospheric pressure plasma; 540; Emission spectroscopy; 530; 01 natural sciences; Plasma diagnosis

In this work, we present a new method allowing the determination of both the gas temperature and the air fraction in non-thermal atmospheric helium plasmas. This new UV-Atomic Emission Spectroscopy technique based on the measurement of the collisional broadening of the He I 667.82 nm and He I 728.13 nm emission lines is a particularly sensible method under low gas temperature conditions; hence it is particularly suitable for the diagnosis of cold helium atmospheric plasmas of biomedical use. To quantify the unknown amount of air entering these plasma jets is key to understanding the chemistry in them and the basis of their clinical and biological action, as it determines the amount of reactive oxygen and nitrogen they generate. The method has been applied to diagnose microwave helium plasmas generated inside three different reactors, thus in environments with different air contents.