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Machida, S.

Paper Title Page
THYAB01 Muon Accelerators 2614
 
  • S. Machida
  
  Funding: The work is supported by the UK Neutrino Factory/Particle Physics and Astronomy Research Council (PPARC) under Contract No. 2054.

Accelerator of muon has to have very large acceptance and very quick acceleration. Recent study shows that FFAGs (in particular non-scaling) are one of the most promising candidates for muon accelerators as building block for a neutrino factory. There are, however, some unresolved problems which should be studied in more detail. We will talk about mostly beam dynamics issues of the muon accelerators, not only FFAG, but other candidates such as linac and RLA and compare their performance.

 
slides icon Slides  
MOPAN028 Current Status of Virtual Accelerator at J-PARC 3 GeV Rapid Cycling Synchrotron 215
 
  • H. Harada
  • K. Furukawa
    KEK, Ibaraki
  • H. Hotchi, Y. Irie, F. Noda, H. Sako, H. Suzuki
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • S. Machida
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  • K. Shigaki
    Hiroshima University, Higashi-Hiroshima
  
  We have developed the logical accelerator called "Virtual Accelerator" based on EPICS for 3 GeV Rapid Cycling Synchrotron (RCS) in J-PARC. The Virtual Accelerator has a mathematical model of the beam dynamics in order to simulate the behavior of the beam and enables the revolutionary commissioning and operation of an accelerator. Additionally, we have constructed the commissioning tool based on the Virtual Accelerator. We will present a current status of the Virtual Accelerator system and some commissioning tool.  
TUPAN061 Updated Simulation for the Nuclear Scattering Loss Estimation at the RCS Injection Area 1526
 
  • P. K. Saha
  • H. Hotchi, Y. Irie, F. Noda
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • S. Machida
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  
  We have updated the simulation for the realistic beam loss estimation at the RCS (Rapid Cycling Synchrotron) injection area of J-PARC(Japan Proton Accelerator Research Complex). At the injection area, beam loss caused by the nuclear scattering together with the multiple coulomb scattering at the charge-exchange foil is the dominant one and is an important issue for designing mainly the foil thickness and other beam elements like, the falling time of bump magnets after the injection is finished and so on. The simulation tool GEANT for the scattering effect and the real injection process have been employed together in order to estimate the beam loss turn by turn including identification of loss points too.  
THPMN082 Beam Injection Into EMMA Non-scaling FFAG 2898
 
  • T. Yokoi
  • S. Machida
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  
  FFAG accelerators have been getting attention as promising candidates for the muon accelerators of a neutrino factory due to their large transverse acceptance and the capability of fast particle acceleration. Non-scaling FFAGs, which are a variation of FFAGs, are nowadays being intensively studied for their simple structure and operational flexibility. To demonstrate the technical feasibility of non-scaling FFAGs and to investigate their beam dynamics, a project to construct a small electron non-scaling FFAG (EMMA) has been proposed in the UK. In EMMA the injection and extraction energies must be arbitrarily changed for a beam with emittance of 3 mm to study the beam dynamics in detail for the entire range of operating energy. In addition, in the planned machine the betatron tunes vary more than a factor of two during acceleration. The requirement of variable injection or extraction energy requires careful optimisation of the of injection elements and operational conditions. The details and design status of the scheme will be described in this paper.  
THPMS083 The EMMA Lattice Design 3181
 
  • J. S. Berg
  • S. R. Koscielniak
    TRIUMF, Vancouver
  • S. Machida
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  • A. G. Ruggiero
    BNL, Upton, Long Island, New York
  
  Funding: Work Supported by the United States Department of Energy, Contract No. DE-AC02-98CH10886.

EMMA is a 10 to 20 MeV electron ring designed to test our understanding of beam dynamics in a relativistic linear non-scaling fixed field alternating gradient accelerator (FFAG). This paper describes the design of the EMMA lattice. We begin with a description of the experimental goals that impact the lattice design. We then describe what motivated the choice for the basic lattice parameters, such as the type of cells, the number of cells, and the RF frequency. We next list the different configurations that we wish to operate the machine in so as to accomplish our experimental goals. Finally, we enumerate the detailed lattice parameters, showing how these parameters result from the various lattice configurations.

 
FRPMN036 Resonance Correction systems for JPARC Main Ring 4024
 
  • A. Y. Molodozhentsev
  • T. Koseki, M. Tomizawa
    KEK, Ibaraki
  • S. Machida
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  
  The injection time for the JPARC Main Ring for the basic scenario is about 120ms, which corresponds to about 20,000 turns. The particle losses at the Main Ring collimator should be less than 1% from the expected maximum beam power at the injection energy. To keep the particle losses for the Main Ring operation below the limit, the correction systems have been suggested to eliminate possible resonance excitation. The proposed correction schemes allow us to suppress linear and nonlinear resonances. The calculated and/or measured field data for main magnets of the ring has been taken into account for this study.  
FRPMN046 Effects of Magnetic Field Tracking Errors on Beam Dynamics at J-PARC RCS 4078
 
  • H. Hotchi
  • S. Machida
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  • F. Noda
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  
  The 3-GeV Rapid-Cycling Synchrotron (RCS) of J-PARC aims at providing a 1-MW proton beam at a repetition rate of 25 Hz for an injection energy of 400 MeV. In this paper, we discuss influences of field tracking errors between dipoles and quadrupoles and between different families of quadrupoles on beam dynamics in combination with effects of the space charge and intrinsic nonlinear fields for the J-PARC RCS.