Keyword: proton
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TUP11 The Interaction Between Electrons and Ions in Comoving and Static Electron Columns ion, electron, HOM, space-charge 47
 
  • V.A. Britten, M. Droba, O. Meusel, H. Podlech, A. Schempp, K. Schulte
    IAP, Frankfurt am Main, Germany
 
  The interaction between electrons and positive ion beams and its application in accelerator physics are investigated. A space charge lens named Gabor lens was developed which confines electrons in a static column by external fields. The confined electrons are used for focusing and may support space charge compensation. In this structure the relative velocity between the ions and the electrons is maximal and corresponds to the beam velocity. An electron lens as at the Tevatron* is operated with a lower relative velocity in order to compensate the beam, to clean the beam abort gap or to excite the beam for beam dynamics measurements. In comparison electron cooling needs the same velocity of the ion and the electron beam. The following study contains the superposition of electric and magnetic self-fields and their impact on the density distribution of the ion beam and of the electron beam. Recombinations and ionisations are neglected. This is the beginning of an interface between these topics to find differences and similarities of the interaction between ions and electrons with different relative velocities. This may open up opportunities e.g. for the diagnostics of particle beams.
* Shiltsev, Vladimir, et al. "Tevatron electron lenses: Design and operation." Physical Review Special Topics-Accelerators and Beams 11.10 (2008): 103501.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-COOL2017-TUP11  
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TUP15 Experimental Demonstration of Electron Cooling with Bunched Electron Beam electron, ion, experiment, storage-ring 61
 
  • L.J. Mao, J. Li, X.M. Ma, M.T. Tang, J.C. Yang, X.D. Yang, H. Zhao, H.W. Zhao
    IMP/CAS, Lanzhou, People's Republic of China
  • A. Hutton, K. Jordan, T. Powers, R.A. Rimmer, M. Spata, H. Wang, S. Wang, H. Zhang, Y. Zhang
    JLab, Newport News, Virginia, USA
 
  Funding: This work was supported by the Hundred Talents Project of the Chinese Academy of Sciences and National Natural Science Foundation of China (Nos. 11575264, 11475235, 11375245)
Electron cooling at high energy is presently considered for several ion colliders, in order to achieve high luminosities by enabling a significant reduction of emittance of hadron beams. Electron beam at cooling channel in a few to tens MeV can be accelerated by a RF/SRF linac, and thus using bunched electrons to cool bunched ions. To study such cooling process, the DC electron gun of EC35 cooler was modified by pulsing the grid voltage, by which a 0.5-3.5 us of electron bunch length with a repetition frequency of less than 250 kHz was obtained. The first experiment demonstrated cooling coasting and bunched ion beam by a bunched electron beam was carried out at the storage ring CSRm at IMP. A preliminary data analysis has indicted the bunch length shrinkage and the momentum spread reduction of bunched 12C+6 ion beam. A longitudinal grouping effect of coasting ion beam by the electron bunch has also observed. In this paper, we will present the experiment result and its preliminary comparison to the simulation modeling.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-COOL2017-TUP15  
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TUP17 Design of Stochastic Pick-Ups and Kickers for Low Beta Particle Beams ion, kicker, impedance, experiment 68
 
  • B. Breitkreutz, R. Stassen, H. Stockhorst
    FZJ, Jülich, Germany
 
  The COSY facility hosts experiments for the JEDI (Jülich Electric Dipole moment Investigations) collabora-tion. Polarized deuteron beams with a momentum of 970 MeV/c are stored in the ring. To achieve polarization times in the order of several minutes, small emittances and momentum spread are crucial. Therefore, the beam is pre-cooled with the 100-kV electron cooler. To further improve the spin coherence time, cooling during the experiments would be desirable. That way, the beam blow-up due to intra beam scattering could be compen-sated. But since the focusing solenoids in the e-cooler may not be perfectly compensated, it cannot be used to cool during the experiments. The existing stochastic cooling (SC) system is not sensitive at low beam veloci-ties. Thus, it is proposed to build a dedicated SC system for low beta beams. This work presents the proposed sys-tem. It emphasizes the design process of pick-up and kicker hardware. Starting from the slot-ring structures that have been developed for HESR, an optimization towards a high sensitivity at a beta of 0.46 is undertaken.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-COOL2017-TUP17  
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WEM12 Development of a Bunched Beam Electron Cooler Based on ERL and Circulator Ring Technology for the Jefferson Lab Electron-Ion Collider ion, electron, solenoid, simulation 72
 
  • S.V. Benson, Y.S. Derbenev, D. Douglas, F.E. Hannon, A. Hutton, R. Li, R.A. Rimmer, Y. Roblin, C. Tennant, H. Wang, H. Zhang, Y. Zhang
    JLab, Newport News, Virginia, USA
 
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
Jefferson Lab is in the process of designing an electron ion collider with unprecedented luminosity at a 45 GeV center-of-mass energy. This luminosity relies on ion cooling in both the booster and the storage ring of the accelerator complex. The cooling in the booster will use a conventional DC cooler similar to the one at COSY. The high-energy storage ring, operating at a momentum of up to 100 GeV/nucleon, requires the novel use of bunched-beam cooling. There are two designs for such a bunched beam cooler. The first uses a conventional Energy Recovery Linac (ERL) with a magnetized beam while the second uses a circulating ring to enhance both the peak and average current experienced by the ion beam. This presentation will describe the design of both the Circulator Cooling Ring (CCR) design and that of the backup option using the stand-alone ERL operated at lower charge but higher repetition rate than the ERL injector required by the CCR-based design.
 
slides icon Slides WEM12 [5.124 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-COOL2017-WEM12  
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THM13 Commissioning of the Low Energy Storage Ring Facility CRYRING@ESR ion, storage-ring, MMI, injection 81
 
  • F. Herfurth, Z. Andelkovic, M. Bai, A. Bräuning-Demian, V. Chetvertkova, O. Geithner, W. Geithner, O.E. Gorda, M. Lestinsky, S.A. Litvinov, G. Vorobjev, U. Weinrich
    GSI, Darmstadt, Germany
  • A. Källberg
    Stockholm University, Stockholm, Sweden
  • T. Stöhlker
    HIJ, Jena, Germany
 
  CRYRING@ESR is the early installation of the low-energy storage ring LSR, a Swedish in kind contribution to FAIR, which was proposed as the central decelerator ring for antiprotons at the FLAIR facility. An early installation opens the opportunity to explore part of the low energy atomic physics with heavy, highly charged ions as proposed by the SPARC collaboration but also experiments of nuclear physics background much sooner than foreseen in the FAIR general schedule. Furthermore, the ring follows in large parts FAIR standards, and is used to test the FAIR control system. CRYRING@ESR has been installed behind the existing experimental storage ring ESR starting in 2013. It has a local injector that is used for commissioning. In November 2016 the commissioning of the storage ring started and a first turn was achieved. After a complete bake out cycle and substantial developments of control system, diagnosis and others, commissioning was continued in late summer 2017. Stored as well as accelerated beam has been achieved by now. The remaining step is to take the electron cooler into operation, which is planned for November this year.  
slides icon Slides THM13 [4.318 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-COOL2017-THM13  
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