Interaction of fast Hn+ with the last layers of carbon foils

A Monte Carlo program describing the Penetration of H(n)+ hydrogen clusters in thin foils has been used to build a model of charge exchange for protons resulting from the breakup of these clusters. The total neutral fractions observed at emergence with cluster projectiles H(n)+, n < 23 in the energy range 40-120 keV/u, as well as the number of 2p excited states are well reproduced by these calculations taking into account geometrical structures of the projectiles and vicinity effects.