Abstract
Present work gives for the first time the formulation of the two-center Coulomb-Born approximation (TCCBA) and presents some calculations for the electron-impact excitations in electron-ion-ion systems. The effect of the third body was relatively small in the cases studied so far. However, if the third body is a bare ion with a charge larger than the target ion, there will be a marked influence of the three-body collisions. Utilizing TCCBA we present the total and partial cross sections of hydrogen-like ions He+(Z=2), and C5+(Z=6) in the hydrogen plasma from the ground states 1s to the excited states 2s and 2p0, 2p_± for the collision energies from 0.4Z2 to 2Z2 a.u.; for the excited states of the target ions, Stark effect is also studied. It is found that the presence of another ion have little effect on the 1s-2s transition and the 2s-2p Stark mixing has a prominent effect.
