Spectral line broadening by relativistic electrons in plasmas: Collision operator

In the present work we compute the real part of the impact collision operator for the electron broadening of ion lines in plasmas, taking into account relativistic effects in the dynamics of the perturbing electron. Specifically two relativistic effects are included: The modification of the trajectory due to non-Newtonian mechanics and the modification of the velocity distribution (Maxwell-Juttner). The results are compared to the non-relativistic case.