[Spectrum of dielectric barrier discharge at atmospheric pressure intensified by mixing a little argon].

In this paper, the spectrum of dielectric barrier discharge at atmospheric pressure was measured by using the special setup with two water electrodes. The variation of spectrum was studied when a little argon was mixed. Nitrogen molecular spectrum (C3 IIu(v' = 0 ) --> B3 IIg(v" = 0-4)) and nitrogen atomic spectrum(4d(4) D7/2 --> 3p(4)P1/2(0)) were found in the range of 300-800nm. After a little argon was mixed, the breakdown voltage of discharge obviously decreased. The spectral line intensities of nitrogen molecules and nitrogen atoms increased. The full width at half maximum (FWHM) of spectral line was obviously broadened. Because Stark broadening is a linear function of electron density, it can be seen that electron density increased after a little argon was mixed with the air, which caused the probability of excitation collision of N2 and N with electrons to increase, and the number of N2 and N excited to higher excitation state to increase. So the intensity of spectrum was intensified.