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Schempp, A.

Paper Title Page
MOP05 The HITRAP-Decelerator for Heavy Highly-Charged Ions 39
  • L. Dahl, W. Barth, T. Beier, W. Vinzenz
    GSI, Darmstadt
  • C. A. Kitegi, U. Ratzinger, A. Schempp
    IAP, Frankfurt-am-Main
  The GSI accelerator facility provides highly charged ions up to U92+ by stripping the ions at 400 MeV/u in the transfer line from the SIS18 (Heavy Ion Synchrotron) to the ESR (Experimental Storage Ring). The ESR provides high quality beams by means of stochastic cooling and electron cooling. Deceleration down to 4 MeV/u was already successfully demonstrated. After suitable rebunching, further deceleration down to 6 keV/u, neccessary for the capture of the ions by a penning trap, is done by IH/RFQ-structures. All cavities are operated at 108 MHz. Recently the HITRAP-project (Heavy Ion Trap), described in a Technical Design Report, was approved. The layout of the decelerator and the beam dynamics in different sections are reported.  
MOP06 A Dedicated 70 MeV Proton Linac for the Antiproton Physics Program of the Future Facility for Antiproton and Ion Research (FAIR) at Darmstadt 42
  • L. Groening, W. Barth, L. Dahl, R. Hollinger, P. Spädtke, W. Vinzenz, S. Yaramishev
    GSI, Darmstadt
  • B. Hofmann, Z. Li, U. Ratzinger, A. Schempp, R. Tiede
    IAP, Frankfurt-am-Main
  The antiproton physics program of the future International Accelerator Facility at Darmstadt is based on a rate of 7·1010 cooled antiprotons per hour. To provide the primary proton intensities a proton linac is planned, which will be operated independently from the existing UNILAC for heavy ions. The proposed linac comprises a proton source, a RFQ, and a DTL. Its operation frequency of 352 MHz allows for an efficient acceleration to up to 70 MeV using normal conducting Crossed-bar H-cavities. These CH-cavities show high shunt impedances as known from IH-structures, but allow for much higher relative particle velocities of up to 40%. The beam pulses with a length of 25 μs, a current of 70 mA, and total transverse emittances of 7 μm will allow to fill the existing synchrotron SIS within one multi-turn-injection up to its space charge limit of 7·1012 protons. The maximum SIS ramping rate limits the applied proton linac repetition rate to 5 Hz. This paper gives an overview of the proposed proton linac. The status of the design including beam dynamic studies will be reported.  
MOP09 Status of the 7 MeV/u, 217 MHz Injector Linac for the Heidelberg Cancer Therapy Facility 51
  • B. Schlitt, K. Dermati, G. Hutter, F. Klos, C. Mühle, W. Vinzenz, C. Will, O. Zurkan
    GSI, Darmstadt
  • A. Bechtold, U. Ratzinger, A. Schempp
    IAP, Frankfurt-am-Main
  • Y.R. Lu
    PKU/IHIP, Beijing
  A clinical synchrotron facility for cancer therapy using energetic proton and ion beams (C, He and O) is under construction and will be installed at the Radiologische Universitätsklinik in Heidelberg, Germany, starting in 2005. The status of the ECR ion source systems, the beam line components of the low energy beam transport lines, the 400 keV/u RFQ and the 20 MV IH-cavity as well as the linac rf system will be reported. Two prototype magnets of the linac quadrupole magnets have been built at GSI and have been tested successfully. A test bench for the 1.4 MW, 217 MHz cavity amplifier built by industry has been installed at GSI including a 120 kW driver amplifier which will be used also for high power tests of the RFQ. A test bench for the RFQ using proton beams is presently being set up at the IAP. RF tuning of the 1:2 scaled IH-DTL model as well as Microwave Studio simulations of the model and the power cavity have been also performed at the IAP [1].

[1] Y.Lu, S.Minaev, U.Ratzinger, B.Schlitt, R.Tiede, this conference.

TUP10 Design of a Deuteron RFQ for Neutron Generation 312
  • Z.Y. Guo, J. Chen, J. Fang, Y.R. Lu, S.X. Peng, Z.Z. Song, J.X. Yu, C. Zhang, K. Zhu
    PKU/IHIP, Beijing
  • A. Schempp
    IAP, Frankfurt-am-Main
  A deuteron RFQ is designed for neutron generation with 9Be(d,n)10B reaction. Considering the limitation of available RF transmitter, the frequency was chosen as 201.5 MHz and the peak RF power was set to 400 kW with 10% duty factor. The deuteron beam will be extracted from an ECR ion source also with 10% duty factor and then be accelerated to about 2 MeV by RFQ with high transmission efficiency. The system will be described and the design results of particle dynamics and structure will be given.  
TUP11 High current RFQ using laser ion source 315
  • M. Okamura, R.A. Jameson, J. Takano, K. Yamamoto
    RIKEN, Saitama
  • R. Becker, A. Schempp
    IAP, Frankfurt-am-Main
  • T. Fujimoto
    AEC, Chiba
  • T. Hattori, N. Hayashizaki
    TIT, Tokyo
  • Y. Iwata, S. Shibuya
    NIRS, Chiba-shi
  • H. Kashiwagi
    JAERI/ARTC, Gunma-ken
  A new RFQ was fabricated for very high current heavy ions. The designed target current is 100 mA with cabon 4+ beam. Acceleration test result will be reported at the conference.  
TUP16 Investigation on Beam Dynamics Design of High-Intensity RFQs 327
  • C. Zhang, A. Schempp
    IAP, Frankfurt-am-Main
  • J. Chen, J. Fang, Z.Y. Guo
    PKU/IHIP, Beijing
  Recently various potential uses of high-intensity beams bring new opportunities as well as challenges to RFQ accelerator research because of the new problems arising from the strong space-charge effects. Unconventional concepts of beam dynamics design, which surround the choice of basic parameters and the optimization of main dynamics parameters’ variation along the machine, are illustrated by the designing Peking University (PKU) Deuteron RFQ. An efficient tool of LANL RFQ Design Codes for beam dynamics simulation and analysis, RFQBAT, is introduced. Some quality criterions are also presented for evaluating design results.  
TUP82 Low Energy Beam Transport using Space Charge Lenses 465
  • O. Meusel, A. Bechtold, H. Klein, J. Pozimski, U. Ratzinger, A. Schempp
    IAP, Frankfurt-am-Main
  Gabor lenses provide strong cylinder symmetric electric focusing using a confined nonneutral plasma. The density distribution of the enclosed space charge is defined by the enclosure conditions in transverse and longitudinal direction. For a homogeneous charge density distribution the resulting electrostatic field and therefrom the focusing forces inside the space charge cloud are linear. Additionally in case of a positive ion beam the space charge of the confined electrons causes compensation of the ion beam space charge forces. To study the capabilities of a Gabor double lens system to match an ion beam into a RFQ a testinjector was installed at the IAP and put into operation successfully. First beam profiles and emittance measurements as well as measurements of the beam energy and energy spread have already been performed and show satisfactory results and no significant deviation from the theoretical predictions. To verify the beam focusing of bunched beams using this lens type at beam energies up to 500 keV a new high field Gabor lens was build and will be installed behind of the RFQ.  
THP08 The Frankfurt Funneling Experiment 614
  • A. Schempp, U. Bartz, N. Müller, J. Thibus, H. Zimmermann
    IAP, Frankfurt-am-Main
  Funneling is a procedure to multiply beam currents of rf-accelerators at low energies. In the ideal case the beam current can be multiplied in several stages without emittance growth. The Frankfurt Funneling Experiment consists of two ion sources, a Two-Beam RFQ accelerator, two different funneling deflectors and a beam diagnostic equipment system. The whole set-up is scaled for He+ instead of Bi+ for the first funneling stage of a HIIF driver. The progress of our experiment and the results of the simulations will be presented.  
THP10 Tuner Design for High Power 4-Rod-RFQs 617
  • A. Schempp, L. Brendel, B. Hofmann, H. Liebermann
    IAP, Frankfurt-am-Main
  The performance of high power RFQ linacs, as used in spallations sources and proposed for projects like ADxy, IFMIF or high duty factor drivers for RIB application are limited by beam dynamics properties as well as technical limits like sparking, power density, cooling and thermal stresses. A "one piece structure" even possible in theory has to have means for tuning the real fields like exchangable or moving tuners. Tuner design features will be discussed and results will be presented.  
THP11 Design of A 352 MHz-Proton-RFQ for GSI 620
  • A. Schempp, L. Brendel, B. Hofmann
    IAP, Frankfurt-am-Main
  Part of the future project of GSI is a new p-linac for the production of Antiprotons. The 4- Rod-RFQ operating at 350 MHz has to accelerate up to 100 mA protons from an ECR source. Design studies have been made using the Parmteq- and Microwave Studio codes to optimize beam dynamics properties and the field distribution of the RFQ. Results of the design studies will be presented.  
THP86 Low Power Measurements on a Finger Drift Tube Linac 800
  • A. Schempp, K.-U. Kühnel
    IAP, Frankfurt-am-Main
  • C.P. Welsch
    MPI-K, Heidelberg
  The efficiency of RFQs decreases at higher particle energies. The DTL structures used in this energy regions have a defocusing influence on the beam. To achieve a focusing effect, fingers with quadrupole symmetry were added to the drift tubes. Driven by the same power supply as the drift tubes, the fingers do not need an additional power source or feedthrough. Beam dynamics have been studied with PARMTEQ . Detailed analysis of the field distribution was done and the geometry of the finger array has been optimized with respect to beam dynamics. A spiral loaded cavity with finger drift tubes was built up and low power measurements were done. In this contribution, the results of the rf simulating with Microwave Studio are shown in comparison with bead pertubation measurement on a prototype cavity.