BEAM-PLASMA INTERACTION EXPERIMENTS WITH HEAVY-ION BEAMS

The progress of the experimental research program at GSI for studying beam-plasma interaction phenomena is reported. Heavy-ions beams from the new accelerator facility SIS/ESR at GSI-Darmstadt are now available for experiments, and will soon deliver greater-than-or-equal-to 10(9) particles per pulse in 100 ns. Focused on a small sample of matter, the beams will be able to produce a high-density plasma and to permit investigation of interaction process of heavy ions with hot ionized matter. For the intense beam from the new heavy-ion synchroton (SIS), a fine-focus system has been designed to produce a high specific deposition power beam for target experiments with a beam-spot radius of 100-mu-m. We further discuss improvements of this lens system by nonconventional focusing devices such as plasma lenses. Intense-beam experiments at the RFQ Maxilac accelerator at GSI have already produced the first heavy-ion-induced plasma with a temperature of 0.75 eV. New diagnostic techniques for investigating ion-beam-induced plasmas are presented. The low-intensity beam from the GSI UNILAC has been used to measure energy deposition profiles of heavy ions in hot ionized matter. In this experiment an enhancement of the stopping power for heavy ions was observed. The current experimental research program tests basic plasma theory and addresses key issues of inertial confinement fusion driven by intense heavy-ion beams.