Electron Impact Excitations and Linear Polarization for 1s2 1S0-1s2p3,1P1 Lines of Fe24＋ Ions under Screened Coulomb Interactions

Electron impact excitation cross sections from the ground state to the individual magnetic sublevels of 1s2p 3＇1P1 states in high-temperature dense plasmas are calculated for highly charged He-like Fe24＋ ions by using a fully relativistic distorted-wave method. The Debye-Huckel screening model is used to screen the projectile electron from the nucleus and target electrons. The linear polarization degrees for these lines are obtained. It is found that the cross sections at all incident energies decrease with the increase of the screening for these excitations. The influence of screening on linear polarization degrees of the 1P1 line is very small. The linear polarization degrees of aP1 line decrease sharply at low incident energy with the increase of the screening.