Author: Katayama, T.
Paper Title Page
MOPEA017 Electron Cooling of Heavy Ions Interacting with Internal Target at HESR of FAIR 103
  • T. Katayama, M. Steck
    GSI, Darmstadt, Germany
  • R. Maier, D. Prasuhn, H. Stockhorst
    FZJ, Jülich, Germany
  The High Energy Storage Ring (HESR) is designed and optimized to accumulate and store the anti-proton beam for the internal target experiment. The recent demand of atomic physics has impacted to use the HESR facility also as the storage ring of bare heavy ions. In this concept the bare heavy ions are injected at 740 MeV/u from the Collector Ring where the ions are well stochastically cooled to be matched with HESR ring acceptance. In the HESR the 2 MeV electron cooler is prepared with the maximal electron current of 3 A and the cooling length of 2.7 m. The electron cooling process of typically 238U92+ beam is simulated for the Hydogen and Xe internal target with simultaneous use of barrier voltage to compensate the mean energy loss caused by the interaction with internal target. In the present report the detailed simulation results of 6D phase space obtained by the particle tracking code are precisely discussed.  
MOPEA018 Feasibility Study of Heavy Ion Storage and Acceleration in the HESR with Stochastic Cooling and Internal Targets 106
  • H. Stockhorst, R. Maier, D. Prasuhn, R. Stassen
    FZJ, Jülich, Germany
  • T. Katayama
    GSI, Darmstadt, Germany
  Stochastic cooling of heavy ions is investigated under the constraint of the present hardware design of the cooling system and RF cavities as well as the given magnet design as foreseen for anti-proton cooling in the HESR of the FAIR facility. A bare uranium beam is injected from the collector ring CR into the HESR at 740 MeV/u. The beam preparation for an internal target experiment with cooling is outlined. The acceleration of the ion beam to 2 GeV/u is studied under the basic condition of the available cavity voltages and the maximum magnetic field ramp rate in the HESR. The cooling simulations include the beam-target interaction due to a Hydrogen and Xenon target. Diffusion due to Schottky and thermal noise as well as intra beam scattering is accounted for. Due to the higher charge states of the ions Schottky particle noise power becomes an important issue. The analysis considers the electronic power limitation to 500 W in case of momentum cooling. Fast Filter cooling is only available if the revolution harmonics do not overlap in the cooling bandwidth. Since overlap occurs for lower energies the application of the Time-Of-Flight (TOF) momentum cooling method is discussed.