Author: Bai, M.
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MOPIK031 COSY Extraction Line Characterization and Modeling 567
 
  • B. Lorentz, M. Bai, Y. Dutheil, R. Tölle, C. Weidemann
    FZJ, Jülich, Germany
 
  COSY is a versatile racetrack-type synchrotron accelerating protons and deuterons in a range of rigidity between 1 T m and 11 T m. Circulating beam can be slowly extracted on a third order resonance and channeled towards different users. New users of the COSY beam have presented new challenges with specific requests, most notably in term of beam shape. This in turn drove a strong interest to develop and improve characterization and modeling methods in the COSY extraction beam line. In this contribution we will present the different beam characterization methods used and their limitations. We will then discuss the modeling of the line and the importance of an accurate and reliable model of the extraction line. Some of the latest beam measurements are presented and compared to modeled results.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK031  
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MOPIK073 Calibration of Linear Optics of COSY Based on ORM Data 699
 
  • C. Weidemann, M. Bai, Y. Dutheil, F. Hinder, B. Lorentz
    FZJ, Jülich, Germany
 
  The COoler SYnchrotron in Jülich is a well suited accelerator for a precursor experiment on the direct measurement of the Electric Dipole Moment (EDM) of the deuteron (see* and references within). It provides polarized and unpolarized proton and deuteron beams in the momentum range between 0.3 GeV/c and 3.65 GeV/c**, allows for phase space cooling and is highly flexible with respect to ion-optical settings***. Unfortunately, a model independent linear optics measurement is not possible and so far the existing MAD-X model of COSY does not provide an agreement with the actual machine parameters that is required by future experiments, such as the EDM experiment. Significant deviations with respect to the working point and linear optics have been reported****. As shown in*****, a MAD-X based LOCO (Linear Optics from Closed Orbits) algorithm in a C++ program was successfully developed and carefully benchmarked. This contribution presents the application of the new program on measured ORM data and its capabilities in calibrating linear optics as well as reconstructing machine imperfections such as gradient errors of quadrupole magnets and calibration factors of BPMs and steerers.
* D. Eversmann et al., PRL 115, no. 9, 094801 (2015).
** R. Maier, NIM A 390, 1 (1997).
*** C. Weidemann et al., PRSTAB 18, 020101 (2015).
**** D. Ji et al., IPAC16, doi:10.18429/JACoW-IPAC2016-TUPMR026.
***** C. Weidemann et al., IPAC16, doi:10.18429/JACoW-IPAC2016-THPMB009.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK073  
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TUPIK050 COSY Slow Orbit Feedback System 1802
 
  • M. Simon, M. Bai, C. Böhme, F. Hinder, B. Lorentz, C. Weidemann
    FZJ, Jülich, Germany
  • J. Bobnar, J. Malec, R. Modic, K. Žagar
    Cosylab, Ljubljana, Slovenia
  • A. Marusic
    BNL, Upton, Long Island, New York, USA
 
  The Cooler Synchrotron (COSY) at Forschungszentrum Jülich is currently carrying out the preparation for a direct measurement of the electric Dipole Moment (EDM) of the deuteron using an RF Wien filter*,**. In a magnetic storage ring with the spin vector aligned along the direction of motion, the EDM manifests in a buildup of the vertical spin component. Besides this signal, radial magnetic fields due to a distortion of the vertical closed orbit can produce a similar signal. This signal is a systematic limit of the proposed measurement procedure. Based on simulation studies***, a vertical closed orbit distortion with a RMS smaller than 0.1 mm is required to achieve a sensitivity of 10-19 e.cm or better. In order to accomplish this challenging goal, a slow orbit feedback system was proposed and recently commissioned at COSY. The design and commissioning results will be presented, and the future plan will also be discussed.
* A. Lehrach et. al, arXiv:1201.5773 [hep-ex].
** W. M. Morse, Y. F. Orlov and Y. K. Semertzidis, PRSTAB 16, no.11, 114001 (2013).
*** M. Rosenthal, Ph.D. thesis, RWTH Aachen University, 2016, available from http://collaborations.fz-juelich.de/ikp/jedi/publicfiles/theses/ThesisMRosenthal.pdf
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK050  
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TUPVA081 An MDM Spin Transparent Quadrupole for Storage Ring Based EDM Search 2264
 
  • Y. Dutheil, M. Bai
    FZJ, Jülich, Germany
  • D. Sagan
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  A storage ring provides an attractive option for directly measuring the electric dipole moment (EDM) of charged particles. To reach a sensitivity of 1029 e.cm, it is critical to mitigate the systematic errors from all sources. This daunting task is pushing the precision frontier of accelerator science and technology beyond its current state of the art. Here, we present a unique idea of a magnetic dipole moment (MDM) spin transparent quadrupole that can significantly reduce the systematic errors due to the transverse electric and magnetic fields that particle encounters.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA081  
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WEPVA049 Vacuum- and Bake-Out-Testbenches for the HESR at FAIR 3366
 
  • H. Jagdfeld, M. Bai, U. Bechstedt, N. Bongers, P. Chaumet, F.M. Esser, F. Jordan, F. Klehr, G. Langenberg, G. Natour, U. Pabst, D. Prasuhn, L. Semke, F. Zahariev
    FZJ, Jülich, Germany
 
  The High-Energy Storage Ring (HESR) is one part of the international Facility for Antiproton and Ion Research (FAIR) at GSI Darmstadt. Forschungszentrum Jülich (IKP and ZEA-1) is responsible for the design and development of the HESR. The HESR is designed for antiprotons and heavy ion experiments as well. Therefore the vacuum is required to be 10-11 mbar or better. To achieve this also in the curved sections, where 44 bent dipole magnets are installed, NEG coated dipole chambers will be used to reach the needed pumping speed and capacity. For activation of the NEG a bake-out system is needed. Two test benches were installed to investigate the required equipment needed to reach this low pressure: A vacuum test bench to investigate the influence of different types and quantity of vacuum pumps for the straight sections of the HESR A bake-out test bench for checking the achievable end pressure and develop the bake-out system for the NEG coated dipole chambers in the curved sections of the HESR The results of the tests and the bake-out concept including the layout of the control system and the special design of the heater jackets inside the dipoles and quadrupoles are presented.
1 Central Institute of Engineering, Electronics and Analytics- Engineering and Technology ZEA-1
2 Institute for nuclear physics
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPVA049  
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WEPVA050 Developments for the Injection Kicker Vacuum System of the HESR at FAIR 3369
 
  • F. Zahariev, M. Bai, N. Bongers, P. Chaumet, F.M. Esser, R. Gebel, H. Glückler, S. Hamzic, H. Jagdfeld, B. Laatsch, W. Lesmeister, L. Reifferscheidt, M. Retzlaff, L. Semke, R. Tölle
    FZJ, Jülich, Germany
  • G. Natour
    Forschungszentrum Jülich GmbH, Central Institute of Engineering, Electronics and Analytics, Jülich, Germany
 
  The Research Center Jülich has taken the leadership of a consortium being responsible for the design and manufacturing of the High-Energy Storage Ring (HESR) going to be part of FAIR. The HESR is designed both for antiprotons and for heavy ion experiments. The injection kicker system of the HESR is located directly behind the septum and consists of two pumping crosses for pumps and measurement devices as well as two vacuum tanks housing the four ferrite magnets which will be operated with 40 kV, 4kA. As well as the magnets, the adjustments frames and the electrical feedthroughs will be installed inside the tanks. Due to the large surface of the magnets the injection kicker system will be very sensitive with regard to the achievable vacuum quality that is expected to be in the order of 10-11 mbar or better. Thus the vacuum system is designed to heat up to 250°C. In order to investigate the achievable end pressure and to develop the heating system a test facility was constructed. The actual vacuum layout of the injection kicker system as well as the experimental test results will be presented and in similar the layout of the control system of the test facility will be described.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPVA050  
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