Temporal and spectral characteristics of atmospheric pressure argon plasma jet

An investigation of atmospheric pressure argon DBD plasma jet generated at 6 kHz sinusoidal voltage was carried out. On the basis of recorded electrical, optical and spectral characteristics spatio-temporal evolution of plasma jet in negative and positive half-cycles of voltage was studied. It was found that the dynamics of argon jet propagation outside the tube differs considerably from that found by other authors in the case of helium jet. The difference was explained with the influence of Penning reactions between metastable state He atoms and air molecules in He jet. On the basis of radiative transitions N-2(C-B, 0-0) and OH(A-X, 0-0) the rotational temperatures of N-2(C, 0) and OH(A, 0) were estimated along jet axis. In regions where Ar-air mixing was negligible or low, the rotational temperatures of both molecules coincide and were close to the gas temperature.