Quasistatic interpretation of the He- and Ne-induced blue asymmetry of the 326.1-nm Cd line shapes in the core and near-wing regions

A blue line shape asymmetry near the center of the Cd 326.1-nm line induced by low-polarizability perturbers (He, Ne) is explained by including the quasistatic contributions to the broadening rate associated with free-free transitions between repulsive branches of potential curves. The resulting shape in the near blue wing is represented by the addition to the Lorentzian and dispersion profiles of a quasistatic component. It is shown that for heavy perturbers (Ar, Kr, Xe) the quasistatic contributions play a marginal role near the line center and the line shape asymmetry arises mainly due to the finite duration of collision. It is also shown that for light perturbers (He, Ne) the quasistatic contributions are much more significant than those due to the collision duration and can adequately describe the blue asymmetry in the core region