Optical and electrical analyses of DC positive corona discharge in N2/O2/CO2 gas mixtures N. Merbahi, A. Abahazem, D. Dubois, O. Eichwald and M. Yousfi Eur. Phys. J. Appl. Phys., 42 1 (2008) 55-61 Published online: 09 April 2008 DOI: 10.1051/epjap:2008035