Diagnostic of 13.56 MHz RF sustained Ar–N2 plasma by optical emission spectroscopyF. U. Khan, N. U. Rehman, S. Naseer, M. A. Naveed, A. Qayyum, N. A.D. Khattak and M. ZakaullahEur. Phys. J. Appl. Phys., 45 1 (2009) 11002DOI: https://doi.org/10.1051/epjap:2008198