Spin Relaxation Effects on the ESR Spectrum of Gaseous Oxygen Atoms

The linewidths of the single-quantum transitions of O(3P1) and O(3P2) in gaseous diluents, such as oxygen molecules and an inter gas, are measured with an ESR spectrometer of a usual type. The cross sections calculated from the pressure broadening are given. With regard to the multiple-quantum transitions in the Zeeman sub-levels of O(3P2) the dependence of the linewidths on the pressure is duscussed. The spin-lattice relaxation time, T1 for the single-quantum transitions of O(3P2) or O(3P2) is evaluated by employing the standard power saturation technique, and the effectiveness of an inert gas on T1 is studied. The spin-lattice relaxation between the Zeeman sublevels of the O atom is caused by the coupling between the orbital momentum and the electron-spin state upon collision. With regard to the multiple-quantum, the relaxation mechanism is also studied. Finally, we study the relationship between the spin-lattice relaxation time, T1, and the corresponding probabilities of ΔMJ=±1, ΔMJ=±2, ΔMJ=±3, and ΔMJ=±4 transition induced by collisions.