Population inversions in recombining hydrogen,nitrogen, and oxygen atomic plasmas

The possibility of population inversions in atomic hydrogen, oxygen and nitrogen plasmas has been investigated by solving a system of master equations describing the temporal evolution of the electronic levels exposed to the action of collisional and radiative processes. The results show that population inversions can be obtained for both quasistationary and fast, transient, recombining plasmas. In this case, the lasing durations of the transitions O(I) 3p³P-3s³S, 3p⁵P-3s⁵S and N(I) 3s²P-2p²D, 3s²P-2p²P⁰ are of the same order of magnitude as the collisional relaxation times of the original states.