On the plasma polarization shift

Possible shifts of spectral ion-lines due to a nonzero mean field, , in a plasma are considered. It is concluded that, in general, it is not consistent to add a term to a ''unified'' or impact theory collision operator. In fact, the correct evaluation of the usual ''shift-width'' operator using quasiparticle interaction potentials (including the monopole term from collisions which penetrate the bound orbit of the radiator) and hyperbolic trajectories (or equivalent perturber wave functions) includes the major portion of the shift. According to the author's analysis, the use of the complete as the shift is only justified when all collisional interactions of second order (and higher) in V are negligible