Bremsstrahlung Coefficients for electron-Hg atom Collisions from the Corrected Phase Shift Approximation

Dalgarno and Lane's [3] approximation, which expresses the bremsstrahlung coefficient in terms of momentum transfer cross sections, has been widely used. This approximation is known to be exact in the "soft photon" or low-frequency limit. Indeed, in the 1967 review article by Johnston [4], it was claimed that the momentum transfer approximation "appears eminently suited" for "most applications of astrophysical interest".