N2(A) as the source of excited species of N2, N and O in a flowing afterglow of N2/NO mixture at atmospheric pressure

Abstract

The kinetic mechanisms of creation and loss of transported species in a flowing afterglow apparatus at atmospheric pressure were studied by optical emission spectroscopy over some tens of cm. The feeding gas was nitrogen containing up to 12.5 ppm of NO flowing at 1333 cm s−1 in an afterglow tube of 8 mm diameter. The absolute concentration dependences versus axial distance were measured for four excited species: O(1S), N(2P), N2(B,v′ = 0) and N2(A). They are all related by linear dependence laws, this being explained by the fact that N2(A) contributes linearly to the creation of O(1S), N(2P), N2(B, v′ = 0). Quantitative measured dependences allowed us to estimate creation and loss rates.