The Free-Free Gaunt Factor in an Ionized Medium
A study of the free-free radiative scatterings of electrons in the Debye screened potential. Three different approximate solutions are shown, with different solutions, in general, covering different regions of validity. For the case of greatest physical interest, that of "small screening," the screened Gaunt factor is very simply related to the unscreened Gaunt factor. In particular, a simple criterion is obtained to measure the importance of screening in free-free scattering.