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Kuroda, S.

Paper Title Page
MOPP003 Study of Abnormal Vertical Emittance Growth in ATF Extraction Line 553
 
  • M. Alabau, A. Faus-Golfe
    IFIC (CSIC-UV), Valencia
  • M. Alabau, P. Bambade, J. Brossard, G. Le Meur, C. Rimbault, F. Touze
    LAL, Orsay
  • D. Angal-Kalinin, J. K. Jones
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • R. Appleby, A. Scarfe
    UMAN, Manchester
  • S. Kuroda
    KEK, Ibaraki
  • G. R. White, M. Woodley
    SLAC, Menlo Park, California
  • F. Zimmermann
    CERN, Geneva
 
  Since several years, the vertical emittance measured in the Extraction Line (EXT) of the Accelerator Test Facility (ATF) at KEK, that will transport the electron beam from the ATF Damping Ring (DR) to the future ATF2 Final Focus beam line, is significantly larger than the emittance measured in the DR itself, and there are indications that it grows rapidly with increasing beam intensity. This long-standing problem has motivated studies of possible sources of this anomalous emittance growth. One possible contribution is non-linear magnetic fields in the extraction region experienced by the beam while passing off-axis through magnets of the DR during the extraction process. In this paper, simulations of the emittance growth are presented and compared to observations. These simulations include the effects of predicted non-linear field errors in the shared DR magnets and orbit displacements from the reference orbit in the extraction region. Results of recent measurements using closed orbit bumps to probe the relation between the extraction trajectory and the anomalous emittance growth are also presented.  
MOPP015 Continuously Adjustable Permanent Magnet Quadrupole for a Final Focus 583
 
  • T. Sugimoto, M. Ichikawa, Y. Iwashita, M. Yamada
    Kyoto ICR, Uji, Kyoto
  • M. Kumada
    NIRS, Chiba-shi
  • S. Kuroda, T. Tauchi
    KEK, Ibaraki
 
  A permanent magnet quadrupole with continuous strength adjustability has been fabricated. It has a five-ring-singlet structure, which was proposed by R. L.Gluckstern. Its small overall diameter allows an outgoing beamline to pass closeby. Since the permanent magnet pieces do not have any vibration source in themselves, this magnet could be used as a quadrupole in a final focus doublet. Such a quadrupole system is described.  
MOPP025 Design of the Beam Extraction by Using Strip-line Kicker at KEK-ATF 601
 
  • T. Naito, H. Hayano, K. Kubo, S. Kuroda, T. Okugi, N. Terunuma, J. Urakawa
    KEK, Ibaraki
 
  The developing work of the strip-line kicker system for International linear collider(ILC) is carrying out at KEK*. To confirm the performance of the kicker system, the beam extraction test by using strip-line kicker is in progress at KEK-ATF. The multi-bunch beam, which has 2.8ns bunch spacing in the damping ring, is extracted from the damping ring to the extraction line with 308ns duration. The scheme is the same as the kicker of the ILC. The bump orbit and the auxiliary septum magnet will be used with the kicker to clear the geometrical restriction. The detail of the hardware design and the basic performance of each component are presented in this paper.

*T. Naito et al. Development of the Strip-line Kicker System for ILC Damping Ring, Proceedings of PAC07, Albuquerque, New Mexico, USA, pp2772-2274.

 
TUPC087 4D Emittance Measurements Using Multiple Wire and Waist Scan Methods in the ATF Extraction Line 1257
 
  • C. Rimbault, P. Bambade, J. Brossard
    LAL, Orsay
  • M. Alabau
    IFIC, Valencia
  • S. Kuroda
    KEK, Ibaraki
  • A. Scarfe
    UMAN, Manchester
  • M. Woodley
    SLAC, Menlo Park, California
 
  Emittance measurements performed in the diagnostic section of the ATF extraction line since 1998 lead to vertical emittances three times larger than the expected ones, with a strong dependence on intensity. An experimental program is pursued to investigate potential sources of emittance growth and find possible remedies. This requires efficient and reliable emittance measurement techniques. In the past, several phase-space reconstruction methods developed at SLAC and KEK have been used to estimate the vertical emittance, based on multiple location beam-size measurements and dedicated quadrupole scans. These methods have been shown to be very sensitive to measurement errors and other fluctuations in beam conditions. In this context new emittance measurements have been performed revisiting these methods and newly developed ones with a systematic approach to compare and characterise their performance in the ATF EXT line.  
TUPP016 A Flight Simulator for ATF2 - A Mechanism for International Collaboration in the Writing and Deployment of Online Beam Dynamics Algorithms 1562
 
  • G. R. White, S. Molloy, A. Seryi
    SLAC, Menlo Park, California
  • P. Bambade, Y. Renier
    LAL, Orsay
  • S. Kuroda
    KEK, Ibaraki
  • D. Schulte, R. Tomas
    CERN, Geneva
 
  The goals of ATF2 are to test a novel compact final focus optics design with local chromaticity correction intended for use in future linear colliders. The newly designed extraction line and final focus system will be used to produce a 37nm vertical waist from an extracted beam from the ATF ring of ~30nm vertical normalised emittance, and to stabilise it at the IP-waist to the ~2nm level. Static and dynamic tolerances on all accelerator components are very tight; the achievement of the ATF2 goals is reliant on the application of multiple high-level beam dynamics algorithms to align and tune the electron beam in the extraction line and final focus system. Much algorithmic development work has been done in Japan and by colleagues in collaborating nations in North America and Europe. We describe here development work towards realising a 'flight simulator' environment for the shared development and implementation of beam dynamics code. This software exists as a 'middle-layer' between the lower-level control systems (EPICS and V-SYSTEM) and the multiple higher-level beam dynamics modeling tools in use by the three regions (SAD, Lucretia and PLACET).  
THPC073 Measurement of Resonance Driving Terms in the ATF Damping Ring 3155
 
  • R. Tomas, F. Zimmermann
    CERN, Geneva
  • K. Kubo, S. Kuroda, T. Naito, T. Okugi, J. Urakawa
    KEK, Ibaraki
 
  The measurement of resonance driving terms in the Damping Ring of the Accelerator Test Facility in KEK could help finding possible machine imperfections and even to optimize single particle stability through the minimization of non-linearities. The first experimental attempts of this enterprise are reported in this note.