Impact parameter dependence of energy loss and charge exchange in ion-atom collisions

Recent calculations of the impact parameter dependence of electronic energy loss and charge exchange probabilities for fast light ions (energy range 100 keV-10 MeV per nucleon) in collisions with atoms are shortly overviewed and discussed. It is shown that the differential energy loss and energy loss straggling for protons can be well described by explicit calculations within the semiclassical approximation and independent electron atomic model. The role of screening and antiscreening is discussed for ions bearing electrons. The electron capture and loss probabilities in ion collisions with complex atoms are considered. It is demonstrated that the existing theories cannot provide unambiguous predictions for the impact parameter dependence of the electron capture probability.