Excitation Mechanisms of the Nitrogen Frist-Positive and First-Negative Radiation at High Temperature

The kinetic mechanisms responsible for the excitation of the first-positive and first-negative emission of nitrogen have been investigated in a re-examination of previously reported shock-tube measurements of the nonequilibrium radiation for these systems. The rate coefficients of the collisional quenching reactions, N2(A 3Σu+)+N(4S)⇒ lim k−2(N)N2(X 1Σg+)+N(4S)and N2+(B 2Σu+)+N2(X 1Σg+)⇒ lim kq(N2)N2+(X 2Σg+) or N2+(A 2Πu)+N2(X 1Σg+)were found to be given by the empirical expressions, k−2(N)=5.1× 10−3 T−2.23 cm3 sec−1 and kq(N2)=1.9 × 10−2 T−2.33 cm3 sec−1, respectively, over the approximate temperature range 6000–14 000°K.