A. Bultel et al., MEASUREMENT OF THE GROUND-STATE AND METASTABLE ATOMIC NITROGEN NUMBERDENSITY IN A LOW-PRESSURE PLASMA-JET, Plasma sources science & technology, 4(4), 1995, pp. 597-605
The radial profiles of metastable and ground state atomic number densi
ties at numerous sections of a supersonic nitrogen plasma jet have bee
n derived from UV absorption and emission spectroscopy. An original me
thod that provides the ground state number density from the ratio of t
he intensities of the 119.955, 120.022 and 120.071 nm resonance lines
has been developed. Along the jet axis direction, and similarly to the
N and N-2(+) excited states, the N ground state density decreases mor
e steeply at the centre of the jet than at its border. At the exit of
the plasma source, our results throw doubt upon the nitrogen dissociat
ion rate usually considered in the literature.