Study of electron excitation of Rb-like to Br-like tungsten ions and polarization of their photon emission

Abstract

A systematic study of the electron impact excitation of highly charged Rb-like W37+ through Br-like W39+ tungsten ions has been done using fully relativistic distorted wave theory. The cross sections are calculated for various transitions in the electron impact energy range from the excitation threshold to 20 keV. Analytic fitting of the calculated cross sections are also provided so that these can be directly used in any plasma model. Linear polarization of the emitted photons, due to decay of the different electron excited states of the tungsten ions has also been obtained and reported.