Generation of Helium atmospheric pressure plasma jet in different shielding gas and its characteristics

Helium atmospheric pressure plasma jet (APPJ) is generated in shielding gas of air and oxygen. Influences of discharge parameters including the applied voltage, driving frequency, and gas flow rate on the jet characteristics are studied. The results show that the plasma jet can propagate longer in air than in oxygen under the same discharge conditions, but the variation trend of plasma jet length in both shielding gases is basically identical at different operating parameters. Electrical and optical diagnosis show that the device has a good stability, repeatability, controllability and security, to produce the plasma jet that meet the needs for cell treatment under the same operating conditions. This is helpful for refined research of the biological effects of ROS and RNS of plasma jet.