Comparative study on the atmospheric pressure plasma jets of helium and argon

Formation mechanisms for atmospheric pressure plasma jets (APPJ) of He and Ar are investigated by comparing the discharge current, light emission from jet, and time-resolved image of the discharge. A longer jet of He (Ar) is available with active (ground) electrode sitting at downstream side. The jet of He outside active electrode arises from corona discharge, while that of Ar outside ground electrode results from charge overflow, and can be diffusive or filamentous in different phases of the applied voltage. The underlying mechanisms are discussed. These results can be helpful for the further mechanism investigation and implementation of APPJs.