Author: Spiller, P.J.
Paper Title Page
MOPS054 Impedance of the Pulse Power Converter for the SIS100 Bipolar Extraction Kicker System 727
 
  • K. Samuelsson, V. Hinrichsen
    TU Darmstadt, Darmstadt, Germany
  • U. Blell, P.J. Spiller
    GSI, Darmstadt, Germany
 
  SIS100 will be operated with high intensity heavy-ion and proton beams. The reduction of ring impedances is therefore of great importance in order to avoid coherent beam instabilities. The kicker system is one of the main contributors to the overall ring impedance in SIS100. This paper will focus on the contribution of the external network to the kicker impedance. Calculations as well as experimental impedance measurements of the network contribution have already been carried out for the SIS18 and ESR kickers. The SIS100 will be equipped with a bipolar kicker system, which uses a Pulse Forming Network (PFN) as energy storage. For potential detachment purposes an insulation transformer will be installed. Since this setup is new in several ways it is important to know its contribution to the coupling impedance of the kicker system. In this contribution the corresponding numerical calculation is presented.  
 
TUPS007 Construction and Test of a Cryocatcher Prototype for SIS100* 1527
 
  • L.H.J. Bozyk, D.H.H. Hoffmann
    TU Darmstadt, Darmstadt, Germany
  • H. Kollmus, P.J. Spiller, M. Wengenroth
    GSI, Darmstadt, Germany
 
  Funding: EU-FP-7 project COLMAT, FIAS
The main accelerator, SIS100, of the FAIR-facility will provide heavy ion beams of highest intensities. Ionization beam loss is the most important loss mechanism at operation with high intensity, intermediate charge state heavy ions. A special synchrotron design has been developed for SIS100, aiming for hundred percent control of ionization beam loss by means of a dedicated cold ion catcher system. To suppress dynamic vacuum effects, the cryo catcher system shall also provide a significantly reduced effective desorption yield. The construction and tests of a prototype cryo ion catcher is a workpackage of the EU-FP-7 project COLMAT. A prototype test setup including cryostat has been constructed, manufactured and tested at GSI under realistic conditions with heavy ion beams of the of the heavy ion synchrotron SIS18. The design and results are presented.
 
 
TUPS032 Overview of EuCARD Accelerator and Material Research at GSI 1602
 
  • J. Stadlmann, H. Kollmus, E. Mustafin, N. Pyka, P.J. Spiller, I. Strašík, N.A. Tahir, M. Tomut, C. Trautmann
    GSI, Darmstadt, Germany
  • L.H.J. Bozyk
    TU Darmstadt, Darmstadt, Germany
 
  Funding: EuCARD is co-funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 227579
EuCARD is a joined accelerator R&D initiative funded by the EU. Within this program, GSI Darmstadt is performing R&D on materials for accelerators and collimators in WP8(ColMat). GSI covers prototyping and testing of a cryogenic ion catcher for FAIR's main synchrotron SIS100, simulations and studies on activation of accelerator components e.g. halo collimatiors as well as irradiation experiments on materials foreseen to be used in FAIR accelerators and the LHC upgrade program. Carbon-carbon composites, silicon carbide and copper-diamond composite samples have been irradiated with heavy ions at various GSI beamlines and their radiation induced property changes were characterized. Numerical simulations on the possible damage by LHC and SPS beams to different targets have been performed. Simulations and modelling of activation and long term radiation induced damage to accelerator components have started. A prototype ion catcher has been built and first experiments have been performed in 2011. New collaborations with other institutes and industry in the EuCARD framework have been established and findings of the joined R&D effort influence decisions in the FAIR project and LHC upgrade.
 
 
WEPC059 Optimization of the Sextupole Scheme and Compensation of the Time-Dependent Field Errors during Slow Extraction from the Superconducting Synchrotron SIS300 2151
 
  • A. Saa Hernandez, P.J. Spiller
    GSI, Darmstadt, Germany
  • U. Ratzinger
    IAP, Frankfurt am Main, Germany
 
  The SIS300 synchrotron, planned for the new Facility for Antiproton and Ion Research (FAIR) at GSI-Darmstadt, will become the first superconducting synchrotron worldwide using cos(θ) magnets for resonant slow extraction. A multi-objective optimization algorithm has been developed for the design of the non-linear magnet scheme. The optimization algorithm makes use of the analytical model for the slow extraction from Kobayashi, the analytical description of the resonance excitation and amplitude-dependent tune-shift from Bengtsson, and corrects the chromaticity in order to fulfill the Hardt condition. As a result, the placement of the chromatic and harmonic sextupole magnets in SIS300, the number of sextupole families and the gradients of these families have been optimized for a high efficiency slow extraction. The algorithm accounts also for the sextupole errors on the dipole magnets, compensating its effects. Furthermore, optimized time-dependent settings for the sextupole magnets are generated to compensate the persistent current decay occurring at slow extraction. Tolerances for the magnets are set for the limits where the compensation is no longer valid.  
 
WEPC091 Studies with a Particle Tracking Code for the SIS100 Resonant Extraction System 2220
 
  • M.M. Kirk, G. Franchetti, H. Klingbeil, P. Moritz, N. Pyka, H. Ramakers, P.J. Spiller, H. Welker
    GSI, Darmstadt, Germany
 
  Several issues concerning the envisaged SIS100 resonant extraction at GSI can be resolved with a simulation-lead approach for which a particle tracking code was developed. Applications to date have included: design and testing of data supply algorithms for the accelerator control system; requirements analysis for the power converter ripple in the quadrupoles forming the doublet focusing; and verification of the RF Knock-Out exciter's performance.  
 
WEPS003 SIS18 – Intensity Record with Intermediate Charge State Heavy Ions 2484
 
  • P.J. Spiller
    GSI, Darmstadt, Germany
  • L.H.J. Bozyk
    FIAS, Frankfurt am Main, Germany
  • P. Puppel
    HIC for FAIR, Frankfurt am Main, Germany
 
  Funding: Project partly funded by the European Community DIRAC-PHASE-1 / Contract number: 515876
In order to reach the desired intensities of heavy ion beams for the experiments at FAIR, SIS18 and SIS100 have to be operated with intermediate charge states. Operation with intermediate charge state heavy ions at the intensity level of about 1011 ions per cycle has never been demonstrated elsewhere and requires a dedicated upgrade program for SIS18 and a dedicated machine design for SIS100. The specific problems coming along with the intermediate charge state operation in terms of charge exchange processes at collisions with residual gas atoms, pressure bumps by ion induced desorption and corresponding beam loss appears far below the typical space charge limits. Thus, new design concepts and new technical equipment addressing these issues are developed and realized with highest priority. The upgrade program of SIS18 addressing the goal of minimum ionization beam loss and stable residual gas pressure conditions has been defined in 2005. A major part of this upgrade program has been successfully realized, with the result of a world record in accelerated number of intermediate charge state heavy ions.
 
 
WEPS094 Dynamic Vacuum Stability in SIS100 2724
 
  • P. Puppel, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  • P.J. Spiller
    GSI, Darmstadt, Germany
 
  SIS100 is the main synchrotron of the FAIR project. It is designed to accelerate high intensity intermediate charge state uranium beams from 200 MeV/u up to 2.7 GeV/u. Intermediate charge state heavy ions are exposed to a high probability of charge exchange due to collisions with residual gas molecules. Since the charge exchange process changes the magnetic rigidity, the involved ions are lost behind dispersive elements, and an energy-dependent gas desorption takes place. The StrahlSim code has been used to predict the stability of the residual gas pressure in SIS100 under beam loss driven dynamic conditions. The results show, that a stable operation at highest U28+ intensities is possible, under the constraint that the vacuum chambers of the ion catcher system are cold enough to pump hydrogen. Furthermore, in order to determine the load to the cryogenic system, the average beam energy deposition onto the ion catcher system has been calculated.