Study of Atmospheric-Pressure Microdischarge by Probe and Spectroscopic Methods

The paper presents a study of the plasma characteristics with non-local properties in an atmospheric-pressure microdischarge generated in a helium flow. Using a wall probe, the plasma parameters were determined: temperature of the main group of electrons; density of metastable atoms and plasma. The impurity content was also assessed $${{{\text{N}}}_{2}}$$ , $${{{\text{O}}}_{2}}$$ n the plasma-forming gas. Additional studies were conducted using optical spectroscopy. A comparative analysis of two methods for determining impurities in buffer helium was conducted. Optical spectroscopy allows one to determine more chemical elements in plasma $${\text{OH}}$$ , $${\text{He}}$$ , $${{{\text{N}}}_{2}}$$ , $${{{\text{O}}}_{2}}$$ , $${\text{O}}$$ and $${\text{N}}$$ , but not under all discharge conditions. It is shown that this discharge cell can act as an independent PLES analyzer for determining the composition of a gas mixture at atmospheric pressure, and does not require maintaining a high vacuum in the detector area.