Dynamic screening effects on collisional orientation phenomena in nonideal plasmas

Dynamic screening effects on orientation phenomena of 1s -> 2p +/- 1 excitations in nonideal plasmas are investigated. A semiclassical method is employed to describe the motion of the projectile electron in order to investigate the variation of the orientation parameter as a function of the impact parameter, projectile energy, thermal energy, and Debye length. The result shows that the preference for the 1s -> 2p(-1) transition significantly decreases with increasing projectile energy. It is found that the dynamic screening effect increases with increasing impact parameter and also with increasing projectile energy. It is also found that the 1s -> 2p(-1) preference decreases with increasing thermal energy.