Determination of atomic constants and collision cross sections by the method of level crossing in gas lasers

An analysis is made of some features of the level crossing method as applied to the excitation of atoms by laser radiation in the experiments carried out with the participation of the present authors. A system of equations is used to find the polarization moments and then the dominant characteristics of spontaneous radiation generated as a result of transitions from active levels. The experiments give the degree of polarization of the radiation and its depolarization by a magnetic field under various conditions (the discharge current, laser radiation power, and composition of the gas mixture are varied). It is shown that these data are sufficient for the determination of the radiative decay time of the active levels, cross sections of depolarizing and quenching collisions, and sometimes also transition probabilities. The method can be applied to cw and pulse cases. The characteristics of some energy levels are determined for neon and cadmium atoms, cadmium ions, and nitrogen molecules.