Spectral study of argon-methane mixture plasma jet generated by a DC plasmatron

Abstract We present the results of studying optical emission spectra of Ar:CH4 plasma produced on a DC plasmatron for graphene synthesis. We have identified the basic set of spectral lines and bands in the obtained spectra and shown that H lines and C2 bands appear due to direct excitation by an electron strike of corresponding neutral particles. C2 molecular bands were also identified in the spectra with intensity considerably lower compared to previous studies where He: C2H2 mixture was used as plasma-forming gas.