Interaction of heavy ions with plasmas

Intense heavy ion beams have been used in recent years to study the properties of matter under extreme conditions. The intense heavy ion beams of the radio frequency accelerator MAXILAC at GSI were used at ion energies of 45 keV/u to produce the first heavy ion driven plasma and to study the hydrodynamic reactions of this plasma. Similar experiments at 300 MeV/u ion energy using the heavy ion synchrotron SIS have now proven to be successful. The understanding and modelling of ion beam driven plasmas requires a precise knowledge of the stopping power in a plasma. Thus, in parallel to the ion beam driven plasmas, the stopping power of a fully ionized hydrogen plasma has been investigated experimentally testing an ion energy range of 45 keV/u to 10 MeV/u at plasma densities from 1016 to 1019 cm-3. The stoppping power experiments revealed the principle of new stopping behavior of ions in a plasma. In comparison to cold, non-ionized matter an increased stopping in hydrogen plasma up to a factor 35 has been observed. (orig.)