State-to-state excitation of NO(A 2Σ+, v′=0,1,2) by N2(A 3Σ+u, v′=0,1,2)

We have determined that the rate coefficient for quenching N2(A 3Σ+u, v′=0) by NO is (6.6±1.0)×10−11 cm3 molecule−1 s−1. Higher levels of N2(A) appear to be quenched with a similar rate coefficient. Separate studies show that the rate coefficient for the excitation of NO(A 2Σ+, v′=0−2) by N2(A 3Σ+u, v′=0) is (10±3)×10−11 cm3 molecule−1 s−1. The apparent discrepancy between the quenching and excitation rate coefficient measurements most likely results from an error in the accepted value of the lifetime N2(A). Our studies indicate that this lifetime is probably about 30% longer than currently believed. We also report rate coefficients for excitation of each of the vibrational levels 0–2 of NO(A) by each of the vibrational levels 0–2 of N2(A) relative to the rate coefficient for excitation of NO(A, v′=0) by N2(A, v′=0).