Author: Arimoto, Y.
Paper Title Page
MOPRI065 The Development of a Low Energy Neutron Accelerator for Rebunching Pulsed Neutrons 751
 
  • S. Imajo
    Kyoto University, Kyoto, Japan
  • Y. Arimoto
    KEK, Ibaraki, Japan
  • Y. Iwashita
    Kyoto ICR, Uji, Kyoto, Japan
  • M. Kitaguchi
    Kyoto University, Research Reactor Institute, Osaka, Japan
  • Y. Seki
    RIKEN Nishina Center, Wako, Japan
  • H.M. Shimizu
    Nagoya University, Nagoya, Japan
  • S. Yamashita
    ICEPP, Tokyo, Japan
  • T. Yoshioka
    Kyushu University, Fukuoka, Japan
 
  Low energy neutrons can be accelerated or decelerated by the technique of AFP-NMR with RF in a gradient magnetic fields. The neutrons have magnetic moments, hence their potential energy are not cancelled before and after passage of magnetic fields and their kinetic energy change finally when their spins are flipped in the fields. Nowadays most measurements of the neutron electric dipole moment (nEDM) are carried out with ultra cold neutrons (UCN), whose kinetic energies are lower than about 300 neV, and with a small storage bottle to reduce the systematic errors. In such experiments highly dense UCNs are desired. The spallation neutron sources generate high-density neutrons at the target, however, the pulsed neutrons with spread velocities are diffused in guide tubes during long beam transport. It is necessary to concentrate UCN temporally upon the bottle by controlling their velocities for nEDM experiments at those facilities. We demonstrated such rebuncher and have been developed the advanced apparatus which makes it possible to handle broader energy range UCN. The design, measured specification of the new rebuncher is described in detail.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI065  
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WEPRI086 Three Dimensional Field Analysis for Final Focus Magnet System at SuperKEKB 2690
 
  • Y. Arimoto, N. Ohuchi, M. Tawada, K. Tsuchiya, H. Yamaoka, Z.G. Zong
    KEK, Ibaraki, Japan
  • B. Parker, P. Wanderer
    BNL, Upton, Long Island, New York, USA
 
  SuperKEKB is an upgrade accelerator of KEKB with a design luminosity of 8x1035 cm-2 s-1. The design is based on a "nano-beam scheme", where vertical beam size is squeezed into 50 nm at an interaction point. One of key component is a final focus magnet system. The focusing system consists of 4-superconducting (SC) quadrupole doublets, 43 SC-correctors, 4 SC-compensation solenoids. They are aligned in a detector (Belle-II) solenoid which generates a longitudinal field of 1.5 T. The system are packed in a small area and also has magnetic shields. So it is expected an entire magnetic field of the system is not one which is linearly-superimposed field of each magnet. Here a study of three dimensional field analysis for the final focus magnet system will be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI086  
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WEPRI087 Magnetic Field Measurement System for the SuperKEKB Final Focus Superconducting Magnets 2693
 
  • N. Ohuchi, Y. Arimoto, M. Iwasaki, M.K. Kawai, Y. Kondo, Y. Makida, K. Tsuchiya, H. Yamaoka, Z.G. Zong
    KEK, Ibaraki, Japan
 
  SuperKEKB are now being constructed with a target luminosity of 8×1035 which is 40 times higher than KEKB. This luminosity can be achieved by the "Nano-Beam" scheme, in which both beams should be squeezed to about 50 nm at the beam interaction point, IP. The beam final focusing system consists of 8 superconducting quadrupole magnets, 4 superconducting solenoids and 43 superconducting corrector coils. The magnetic field measurement systems with the vertical cryostats were designed and constructed for performing the acceptance test of these magnets at 4 K. The field measurements are performed by the 6 different harmonic coils and a Hall probe. The higher order multi-pole field distributions along the magnet axes are very important for the beam operation, and then these distributions are measured with the 20 mm long harmonic coils. The integral fields of quadrupole magnets are measured with the 600 mm long harmonic coils. We will describe the magnetic field measurement system.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI087  
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THPRI005 The Mechanical and Vibration Studies of the Final Focus Magnet-cryostat for SuperKEKB 3770
 
  • H. Yamaoka, Y. Arimoto, K. Kanazawa, M. Masuzawa, Y. Ohsawa, N. Ohuchi, K. Tsuchiya, Z.G. Zong
    KEK, Ibaraki, Japan
 
  Construction of the SuperKEKB has been progressed in KEK. The target luminosity of the SuperKEKB is 8×1035 cm-2s−1, which is 40 times larger than the KEKB. The vertical beam sizes of electron and positron must be squeezed to the level of 50 nano-meter at the interaction point. The beam final focus system for the SuperKEKB consists of 4-superconducting (SC) quadrupole doublets, 43 SC-correctors, 4 SC-compensation solenoids. The designs of the cryostats in the left and right side with respect to the beam interaction point are being studied with the progress of the magnet designs. In the design works, the support structure of each cryostat, strength of the cryostat components and support rods for supporting cold mass are investigated. As for the vibration issue, vibration properties of the superconducting quadrupole magnets due to the ground motion has been studied. Also vibration properties of the concrete bridges where the two cryostats will be placed in the interaction region were investigated and measured. We will present the cryostat designs and these vibration studies in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRI005  
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