Аннотация:The change in the charge fractions Fi (x) and the mean ion charge as the ion energy decreaseswith increasing thickness of the passed layer of matter x is considered. Using the proposed semiempiricalmethod, analytical calculations are carried out for the passage of N ions with initial velocities of V0 = 4 × 108and 6 × 108 cm/s through celluloid. It is shown that in the nonequilibrium region the dependence of thecharge fractions and mean ion charge on x is determined by the initial velocities and initial charges of ions i0,and after reaching charge equilibrium, the mean charges of the ions decrease and the value of the neutral fractionF0 increases with increasing x, regardless of the initial conditions for all considered i0 and V0.