Internal Energy Distribution in MgO(a3Π) Formed From Mg(3P) + O2 and N2O: A Case of Population Inversion

The internal state distribution of MgO(a 3 Π) formed from Mg( 3 P) + O 2 and N 2 O reactions was determined from a reanalysis of the laser induced fluorescence spectra of the d 3 Δ - a 3 Π system previously published by Dagdigian. The MgO(a 3 Π) state formed in the reaction with O 2 has a quasi-Boltzmann distribution. In the N 2 O reaction the rotational excitation is much greater and the vibrational population distribution is inverted with a maximum at v = 2 - 3. The a 3 Π rovibrational population distributions are compared with those of the X 1 ∑ + ground state. The dynamics of these reactions are discussed on the basis of earlier ab-initio calculations and experimental data.