Study on He atmospheric pressure plasma jet based on spectral diagnostics

Dielectric Barrier Discharge (DBD) can generate uniform and high-energy density low-temperature plasma jet at atmospheric pressure, which is often called Atmospheric Pressure Plasma Jet (APPJ). APPJ has a variety of reactive oxygen species and nitrogen products and has important application prospects in surface treatment, biomedicine, food processing, and agriculture. In this paper, the gas temperature, electron excitation temperature, and electron density of helium atmospheric pressure plasma jet (He-APPJ) were diagnosed by Optical Emission Spectroscopy (OES). The experimental results show that the activated particles emitted by He-APPJ plasma contain OH, 𝑁𝑁2 +, Helium, Oxygen, and H at 5500V~6750V. At this high pressure, most gas temperatures remain below 400K, which can be deduced that the He plasma jet is a low-temperature plasma. The electron excitation temperature is around 2000K and the electron density reaches 1014cm-3. The higher the voltage, the higher the electron excitation temperature and electron density.