Evaluation of the rotational temperature in N-2 discharges using low-resolution spectroscopy

An improvement of methods for estimating the rotational temperature from th e partially resolved 391.44 nm emission band of N-2(+) (B(2)Sigma(u)(+)-X(2 )Sigma(g)(+)) has been developed by numerically studying this band as a fun ction both of the temperature and of the instrumental function of the detec tion system. We give a simple tabulation for which one can obtain, without calculation, the rotational temperature in the range 300-900 K from measure ments of the band profile considered and the experimental function. The acc uracy of the temperature evaluation is better than to within 10%. The appro ach is validated in the range 340-410 K, using measurements of the 391.44 n m band in a pure N-2 dc magnetron discharge.