Mean-Charge Change upon the Deceleration of Heavy Ions in Matter

Abstract

The deceleration of fast heavy ions in matter to a complete stop is accompanied by a change in their equilibrium mean charge, which depends on the velocity that decreases as the distance passed increases. A method is proposed for calculating the dependence of the mean ion charge on the thickness of the passed layer of matter, based on the previously proposed power-law approximation for inelastic energy losses. An important role for the successful description of ion energy losses is played by determining the maximum value of energy losses for different ions in various media. The dependence of the maximum energy loss and ion velocity, at which this maximum is observed, on the nuclear charges of incident ions and target atoms is considered. Analytical expressions are obtained for calculating the energy losses and mean charges for ions from boron to neon depending on the thickness of the passed layer of the substance in carbon and silicon.