Author: Ratzinger, U.
Paper Title Page
WEA02 Focusing of Intense Heavy Ion Beams with Plasma Lenses 163
  • O. Meusel, M. Droba, U. Ratzinger, K. Schulte
    IAP, Frankfurt am Main, Germany
  Gabor lenses are a special type of plasma lens using a stable confined electron cloud for beam focusing. The electrons provide space charge neutralization of the beam traveling through the lens volume. At the same time a radial symmetric electrostatic self field focuses the beam mass independently. It is possible to control the density and distribution of the confined electrons providing variable focusing strength and moderate emittance growth of the beam. The knowledge of the behavior of the electron column inside this lens type is essential to understand the impact on beam transport. Therefore several diagnostic tools were developed to measure the electron cloud properties with and without ion beam propagation through Gabor lenses. Based on experimental results a new Gabor plasma lens has been designed for focusing heavy ion beams. A comparison of this lens type and a superconducting solenoid is planned at the low energy transport section of the GSI - High Current Test Injector (HOSTI).  
slides icon Slides WEA02 [1.572 MB]  
WEC03 The SC CW LINAC Demonstrator – 1st Test of an SC CH-cavity with Heavy Ions 182
  • S. Mickat, L.A. Dahl
    GSI, Darmstadt, Germany
  • M. Amberg, K. Aulenbacher, W.A. Barth, V. Gettmann, S. Mickat
    HIM, Mainz, Germany
  • D. Bänsch, F.D. Dziuba, D. Mäder, H. Podlech, U. Ratzinger, R. Tiede
    IAP, Frankfurt am Main, Germany
  The superconducting (sc) continuous wave (cw) LINAC Demonstrator is a collaboration project between GSI, the Helmholtz Institute Mainz (HIM), and the Institute for Applied Physics (IAP) at the Goethe University Frankfurt. The aim is a full performance test of a 217 MHz sc Crossbar H-mode (CH) cavity, which provides gradients of 5.1 MV/m at a total length of 0.69 m. In addition the Demonstrator comprises two 9.3 Tesla sc solenoids. The configuration of a CH-cavity embedded by two sc solenoids is taken from a conceptual layout of a new sc cw LINACwith nine CH-cavities and seven solenoids. Such an accelerator is highly desired by a broad community of users requesting heavy ion beam energies in the Coulomb barrier range. A successful test of such an sc multigap structure are an important milestone towards the proposed cw-LINAC.  
slides icon Slides WEC03 [1.842 MB]  
THB05 The HITRAP Decelerator and Beam Instrumentation 217
  • F. Herfurth, Z. Andjelkovic, W.A. Barth, K. Brantjes, G. Clemente, L.A. Dahl, S. Fedotova, P. Gerhard, M. Kaiser, O.K. Kester, H.J. Kluge, C. Kozhuharov, M.T. Maier, D. Neidherr, W. Quint, A. Reiter, T. Stöhlker, G. Vorobjev, S.G. Yaramyshev
    GSI, Darmstadt, Germany
  • U. Ratzinger, A. Schempp
    IAP, Frankfurt am Main, Germany
  A linear decelerator is being commissioned for heavy, highly-charged ions (HCI) at GSI in Darmstadt/Germany. HCI with only one or few electrons are interesting systems for many different experiments as for instance precision tests of the theory of quantum electrodynamics (QED). In order to transform heavy HCI produced at 400 MeV/u to stored and cooled HCI at low energy the linear decelerator facility HITRAP has been setup behind the experimental storage ring (ESR). The ions are decelerated in the ESR from 400 to 4 MeV/u, cooled and extracted. The ions are then matched to an IH-structure using a double drift buncher, decelerated from 4 to 0.5 MeV/u in the IH, and then down to 6 keV/u in a 4-rod RFQ. To detect and analyze the weak and sparse ion bunches a new type of energy analyzing detector has been developed along with improvements to other “standard” beam instrumentation. One million highly charged ions have been decelerated with the IH from 400 MeV/u to about 0.5 MeV/u per cycle. The RFQ has shown in off-line tests to decelerate ions, however, the measured acceptance does not fit the ion beam from the IH. This requires a refined design, which is underway.  
slides icon Slides THB05 [2.925 MB]