Theoretical study on electron impact excitation and related polarization properties of subsequent radiative emission

The polarization of x-ray line emission from highly charged ions undergoing collisions with an electron beam has been a topic of continuous fundamental interest for decades. The understanding of the processes is important not only to diagnose the electron distribution anisotropy in high temperature plasmas, but also to provide the information on both the incident electrons and the excitation dynamics. Recently, on the basis of the well-known GRASP92/K and RATIP packages, a new fully relativistic distorted wave program, named REIE06 has been developed by our group. In this composition, some selected applications of the program are shown. A special attention has been paid on influences of the higher order effects to the polarization properties of the subsequent photoemission following electron impact excitation process. We hope these works will be helpful for further understanding the contributions from the higher order effects and getting more accurate polarization data. (author)