One atmospheric pressure plasma jet with two modes at a frequency of several tens kHz

This paper reports an experimental study of a plasma jet by using optical measurement and spectroscopic method. The plasma jet, composed of an inner electrode with a sharpen end and an outer water-electrode, has a cross-field configuration. A cross-field mode of the plasma jet is realized when the applied voltage is low. However, a different mechanism of plasma plume generation is involved when the applied voltage is high enough, and a linear-field mode of the plasma jet can be realized. The two different modes of the plasma jet are compared by spectroscopic method and results show that electron energy in linear-filed mode is higher than that in cross-field mode. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3586499]