Energy loss of Clq+ (52 MeV) through dilute H2 target: Evidence of non-linear term and non-Coulombian potential contribution

This report states about correlated charge and energy loss measurements in the collisional system Cl ions (1.5 Mev/u) in H2. A windowless gaseous target with different thicknesses was used to measure simultaneously the charge state distributions (CSD) and the energy losses by the main populated outgoing charge states (q=12–15). The Markov chain of the charge-changing process was deduced from a Monte-Carlo computation of the CSD evolution. The stopping cross-sections for individual charge states were finally deduced from energy loss data. Comparison of the experimental results with detailed calculations gives a clear evidence of relative importance of the individual contribution of non-linear correction terms and of the electron cloud bound to the projectiles. These two effects may be important for HI-ICF scenarios where a non-equilibrium charge state behavior is likely to occur.