Elargissement et deplacement par effet de pression des raies d'absorption de quelques multiplets de l'atome neutre de manganese

The profiles of many absorption lines, belonging to the violet and near ultra-violet resonance multiplets and to two intercombination multiplets of the MnI atom, have been determined in the presence of foreign gases at various pressures for several temperatures.Values of the Lennard-Jones interatomic potential constants have been derived from measurements of the line collision broadening and displacement. These values are tabulated. The temperature dependence of the broadening and displacement parameters, for some perturbers of the violet resonance lines has been examined. The discrepancies between theoretical and experimental values of the van der Waals constants, included in the formula of the Lennard-Jones potential, have been discussed. It is shown that, in the case of complex atoms, terms of multipole-dipole interaction must be included in the interatomic potential expressions.