On the projectile-electron loss in fast collisions with heavy atomic targets

The projectile-electron excitation and loss processes are considered in col lisions with heavy atomic targets in the intermediate-to-high-velocity regi me. In order to describe these processes we use the sudden and Glauber appr oximations. We show that these approximations lead to the same results for electronic cross sections. We estimated cross sections for the total loss f rom H and He+ projectiles. Our results favour the interpretation of the tot al electron loss as a process where the projectile-electron interaction wit h the screened heavy target nucleus dominates over the antiscreening mode.