Emission properties of atmospheric pressure plasma jets on the basis of helium-air and argon-air operating mixtures

The spectral-temporal and energy luminescence characteristics of the "cold" plasma jets generated by the atmospheric pressure barrier discharge in helium-air and argon-air mixtures were experimentally studied and analyzed. The main radiating components of the nitrogen containing low-temperature plasma were observed in radiation spectrum of the generated plasma jets outside the capillary cut-off when an operating mixture is blown through the gas-discharge radiation source, namely, nitrogen molecules N$_{\mathrm{2\thinspace }}(C\,{ }^{3}\Pi_{u} \to B\,{ }^{3}\Pi_{g} $- transition) and nitrogen ions $N_{2}^{+} (B\,{ }^{2}\Sigma_{u}^{+} \to X\,{ }^{2}\Sigma_{g}^{+} $-transition) for helium-air mixture and nitrogen molecules N$_{\mathrm{2\thinspace }}(C\,{ }^{3}\Pi_{u} \to B\,{ }^{3}\Pi _{g} $- transition) for argon-air mixture. At the same time, the radiation power of the "cold" plasma jet increased approximately in 3 times when the argon-air mixture is replaced with the helium-air mixture. The work was supported by a grant of National Academy of Sciences of Ukraine for young scientists (2017--2018).