Vibrational distributions in a flowing nitrogen glow discharge

A spectroscopical investigation of a flowing DC nitrogen discharge is realized for determining the vibrational distributions of radiative excited states and . The distributions are found to be Boltzmannian and the characteristic vibrational temperatures increase with the discharge current but are not affected by the flow rate and pressure variations in the range 1 - 3 Torr. The vibrational distribution of the ground state is deduced from the distribution, following the Franck - Condon principle.