N2+/N2 ratio and temperature 2 measurements based on the first negative N2+ and second positive N2 overlapped molecular emission spectra

The N-2(+)(B(2)Sigma(u)(+)-X(2)Sigma(g)(+)) and N-2(C(3)Pi(u)(+)-B(3)Pi(g)(+)) molecular emission spectra are frequently observed simultaneously in plasmas containing nitrogen. Relative band intensities of these systems are very sensitive to a variation of the N-2(+)/N-2 ratio and temperature. The spectrum, emitted between 3800 and 4000 Angstrom, has been used to measure rotational and vibrational temperatures, and to estimate the N-2(+)/N-2 ratio when the electron temperature is known, in different plasma sources (Glidarc, ac discharge between tips). The proposed method is based on a point-to-point comparison of an experimentally measured spectrum with the computer-simulated one.