ENERGY-LOSS OF FAST HEAVY-IONS IN PLASMAS

Interaction processes of heavy ions and ionized matter have been inves tigated experimentally. A Monte Carlo code to simulate charge exchange and energy loss processes in a plasma environment has been developed to plan the experiments, to analyze the results, and to investigate th e influence of magnetic fields on the particle trajectories inside the plasma target. The first results of the beam plasma interaction exper iments are: The stopping power of ionized matter is increased compared to that of cold, non-ionized matter. This effect is especially pronou nced at low ion energies (E < 100 keV/u) where an enhancement factor o f up to 40 has been observed. At higher energies (E > 1 MeV/u) this ef fect is less dramatic, but is still on the order of 2-3, depending on the ion species. The charge state of ions traversing a fully ionized p lasma is increased due to reduced capture cross sections of free plasm a electrons. It is possible to focus intense heavy ion beams of high m agnetic rigidity using a plasma lens. This ideal focusing device achie ves a high focusing power for ion beams almost comparable to optical s ystems for intense beams from high power lasers. Energetic ion beams a re very well suited to heat cylindrical target volumes and to create a dense plasma. The characteristic inner-shell target and projectile X- rays provide a tool to analyze the hydrodynamic behavior of beam heate d targets with space and time resolution.