Orientation phenomena for electron-ion collisional excitations in strongly coupled plasmas

In strongly coupled plasmas, the orientation phenomena for direct excitations in electron-hydrogenic ion collisions are investigated using the ion-sphere interaction potential. For small impact parameters, the orientation parameters have minima which correspond to the complete transitions. The target screening effects slightly increase the probability of populating the 2p_-1 state. Received: 16 December 1998 / Received in final form: 23 March 1999