The maintenance and flow of the atmospheric pressure plasma jet in different kinds of gas environment will inevitably lead to different degrees of mixing of the jet working gas and the background gas

thereby affecting the plasma jet characteristics. To solve this problem

we compared the jet shape

electrical characteristics and discharge products of plasma jets under different gas environments by means of electrical characteristic measurement and emission spectrum diagnosis. Moreover

we investigated the effects of air

nitrogen

argon and helium on the jet characteristics of atmospheric pressure helium plasma. The results reveal that the background gas will intervene in the evolution of the atmospheric pressure helium plasma jet and cause the plasma jet characteristics to change; the background gas that can react with He via Penning ionization will promote the development of atmospheric pressure helium plasma jet

and electronegativity gas and low-excited background gas will hinder its development; if there is Penning ionization in the atmospheric pressure helium plasma jet

the higher the ionization energy of the main constituent gases such as rare gas and air in the background environment is

the farther the atmospheric pressure He plasma jet will propagate.