Collisional Broadening of the Na-D Lines by Molecular Gases

The experimental investigations devoted to the Na-D spectral line broadening by molecular gases are reviewed. The theoretical interpretation of the data within the framework of the classical theory of atomic spectral line broadening is given. The effect of adiabatic and diabatic collisions on the shape of both impact and quasi-static spectral-line wings is discussed. The different forms of spectral-line shape representation and the connections between them are considered. The experimental cross-sections of the Lorentzian broadening of the Na-D lines by molecules are presented and compared with the theoretical ones. The problem of restoration of the adiabatic interaction potentials from quasi-static wing profiles is noted. The C 6 , C 12 parameters of the effective atom-molecular potentials of the Lennard-Jones 12-6 form, restored on quasi-static wing profiles, are presented.