Quenching rate of N(2P) atoms in a nitrogen afterglow at atmospheric pressure

We present the results of an experimental determination of the quenching rate of the metastable 2P state of atomic nitrogen by nitrogen molecules. 2D density profiles of N(2P) and N(4S) atoms were measured by absolute optical emission spectroscopy inside a tube placed downstream of an atmospheric pressure pulsed discharge in nitrogen. The results are analyzed by means of a detailed kinetic model taking into account the major processes of production and depletion of N(2P). The quenching rate constant of N(2P) by N2 molecules determined with this method at atmospheric pressure and T = 300 K is k = (3 ± 1) × 10−17 cm3 s−1.