抄録
By application of 1μs rectangular pulse voltage, N2/He atmospheric-pressure non-equilibrium plasma is generated. The temporally resolved optical emission spectra of the N2 second positive system (2PS) bands are measured to diagnose the plasma characteristics such as the gas temperature and the excitation of N2. Remarkable deviation of the 2PS (0,0) band spectra from the theoretical spectra, which are computed by assuming the Boltzmann distribution of N2 population among the rotational levels, is observed, while the (0,3) band spectra are represented well by the computed spectra. These can be explained by the consequence of the high excitation rate of N2 to the C 3Πu state. The gas temperature is evaluated to be 350±30K from the N2 rotational temperature determined by nonlinear least square fitting of the theoretical spectra to the measured (0,3) band spectra.