Abstract
The unique combination of a high-energy Nd:glass laser system and the intense heavy-ion beam at Gesellschaft für Schwerionenforschung (GSI) allowed for the first time the measurement of the stopping power of heavy ions in plasmas at the level of one percent solid-state density and temperatures of about 60 eV. Energy loss measurements of swift heavy ions (5–6 MeV/u) in a carbon plasma revealed a stopping power exceeding theoretical predictions which was not observed in earlier experiments at lower plasma densities. This discrepancy can be resolved assuming higher effective charge states of the projectiles resulting in a consistent picture for the measured parameter range.