ENERGY LOSS OF IONS IN PLASMA BEYOND THE LINEAR INTERACTION REGIME

This presentation reports on the recent experimental results on the ion energy loss in plasma obtained with the UNILAC and PHELIX facilities of GSI. Two unexplored regimes of ion stopping, highly relevant for Inertial Confinement Fusion, have been studied. On the one hand, the energy loss of light ions was measured in an ideal laser-induced carbon plasma at a low beam velocity corresponding to the maximum of the stopping power. On the other hand, the energy loss and the exiting charge-state distribution of a heavy ion beam were measured, at relatively high beam velocity, in a moderately coupled carbon plasma created by laser-induced x-rays in a hohlraum cavity. In both cases, the stopping behavior remains largely unknown. The energy loss data, deduced from time-of-flight measurements, are compared with theoretical predictions using plasma and ion-beam simulations as well as usual stopping-power models. Significant discrepancies between the data and the predictions are found.