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Yonehara, K.

Paper Title Page
MOPP071 Intense Stopping Muon Beams 712
 
  • M. A.C. Cummings, R. J. Abrams, R. P. Johnson, C. Y. Yoshikawa
    Muons, Inc, Batavia
  • C. M. Ankenbrandt, M. A. Martens, D. V. Neuffer, K. Yonehara
    Fermilab, Batavia, Illinois
 
  The study of rare processes using stopping muon beams provides access to new physics that cannot be addressed at energy frontier machines. The flux of muons into a small stopping target is limited by the kinematics of the production process and by stochastic processes in the material used to slow the particles. Innovative muon beam cooling techniques are being applied to the design of stopping muon beams in order to increase the event rates in such experiments. Such intense stopping beams will also aid the development of applications such as muon spin resonance and muon-catalyzed fusion.  
WEPD013 Four-Coil Superconducting Helical Solenoid Model for Muon Beam Cooling 2431
 
  • V. S. Kashikhin, N. Andreev, A. N. Didenko, V. Kashikhin, M. J. Lamm, A. V. Makarov, K. Yonehara, A. V. Zlobin
    Fermilab, Batavia, Illinois
  • R. P. Johnson, S. A. Kahn
    Muons, Inc, Batavia
 
  Novel configurations of superconducting magnets for helical muon beam cooling channels and demonstration experiments are being designed at Fermilab. The magnet system for helical cooling channels has to generate longitudinal solenoidal and transverse helical dipole and helical quadrupole fields. This paper discusses the Helical Solenoid model design and manufacturing of a 0.6 m diameter, 4-coil solenoid prototype to prove the design concept, fabrication technology, and the magnet system performance. Results of magnetic and mechanical designs with the 3D analysis by TOSCA, ANSYS and COMSOL will be presented. The model quench performance and the test setup in the FNAL Vertical Magnet Test Facility cryostat will be discussed.  
WEPD014 Magnets for the MANX 6-D Muon Cooling Demonstration Experiment 2434
 
  • V. S. Kashikhin, N. Andreev, V. Kashikhin, M. J. Lamm, K. Yonehara, A. V. Zlobin
    Fermilab, Batavia, Illinois
  • M. Alsharo'a, R. P. Johnson, S. A. Kahn, T. J. Roberts
    Muons, Inc, Batavia
 
  MANX is a 6-dimensional muon ionization-cooling experiment that has been proposed to Fermilab to demonstrate the use of a helical cooling channel (HCC) for muon beam emittance reduction for future muon colliders and neutrino factories. The HCC for MANX has solenoidal, helical dipole, and helical quadrupole magnetic components, which diminish as the beam loses energy as it slows down in the liquid helium absorber inside the magnet. The proposed magnet system design is comprised of coil rings positioned along a helical path, which will provide the desired solenoidal and helical dipole and quadrupole fields. Additional magnets that provide emittance matching between the HCC and the upstream and downstream spectrometers are also described. The results of a G4Beamline simulation of the beam cooling behavior of the magnet and absorber system will be presented.  
WEPP123 Isochronous Pion Decay Channel for Enhanced Muon Capture 2785
 
  • C. Y. Yoshikawa, C. M. Ankenbrandt, D. V. Neuffer, M. Popovic, K. Yonehara
    Fermilab, Batavia, Illinois
  • R. J. Abrams, M. A.C. Cummings, R. P. Johnson
    Muons, Inc, Batavia
  • Y. S. Derbenev
    Jefferson Lab, Newport News, Virginia
 
  Intense muon beams have many potential applications, including neutrino factories and muon colliders. However, muons are produced in tertiary beams into a diffuse phase space. To make useful beams, the muons must be rapidly cooled before they decay. A promising new concept for the collection and cooling of muon beams is being investigated, namely, the use of a nearly Isochronous Helical Transport Channel (IHTC) to facilitate capture of muons into RF bunches. Such a distribution could be cooled quickly and coalesced into a single bunch to optimize the luminosity of a muon collider. We describe the IHTC and provide simulations demonstrating isochronicity, even in the absence of RF and absorber.  
WEPP153 Status of the MANX Muon Cooling Experiment 2844
 
  • K. Yonehara, D. R. Broemmelsiek, M. Hu, A. Jansson, V. Kashikhin, V. S. Kashikhin, M. J. Lamm, M. L. Lopes, V. D. Shiltsev, V. Yarba, M. Yu, A. V. Zlobin
    Fermilab, Batavia, Illinois
  • R. J. Abrams, M. A.C. Cummings, R. P. Johnson, S. A. Kahn, T. J. Roberts
    Muons, Inc, Batavia
 
  MANX is an experiment to prove that effective six-dimensional (6D) muon beam cooling can be achieved a Helical Cooling Channel (HCC) using ionization-cooling with helical and solenoidal magnets in a novel configuration. The aim is to demonstrate that 6D muon beam cooling is understood well enough to plan intense neutrino factories and high-luminosity muon colliders. The experiment consists of the HCC magnets that envelop a liquid helium energy absorber, upstream and downstream instrumentation to measure the particle or beam parameters before and after cooling, and emittance matching sections between the detectors and the HCC. Studies are presented of the effects of detector resolution and magnetic field errors on the beam cooling measurements.  
MOPP080 Studies of Breakdown in a Pressurized RF Cavity 736
 
  • M. BastaniNejad, A. A. Elmustafa
    Old Dominion University, Norfolk, Virginia
  • M. Alsharo'a, P. M. Hanlet, R. P. Johnson, S. Korenev, M. Kuchnir, D. J. Newsham, R. Sah
    Muons, Inc, Batavia
  • C. M. Ankenbrandt, A. Moretti, M. Popovic, K. Yonehara
    Fermilab, Batavia, Illinois
  • D. M. Kaplan
    Illinois Institute of Technology, Chicago, Illinois
  • D. Li
    LBNL, Berkeley, California
  • D. Rose, C. H. Thoma, D. R. Welch
    Voss Scientific, Albuquerque, New Mexico
 
  Previous studies of RF breakdown in a cavity pressurized with dense hydrogen gas have indicated that breakdown probability is proportional to a high power of the surface electromagnetic field. This behavior is similar to the Fowler-Nordheim description of electron emission from a cold cathode, and it implies that breakdown is a quantum mechanical effect that is characterized by the work function of the cavity metal. We describe our present efforts to measure the distributions of work functions at the nanoscale level on the surfaces of the electrodes used in breakdown studies, and to understand how the RF conditioning process affects them.  
MOPP090 Incorporating RF into a Muon Helical Cooling Channel 760
 
  • S. A. Kahn, M. Alsharo'a, R. P. Johnson
    Muons, Inc, Batavia
  • D. R. Broemmelsiek, A. Jansson, V. Kashikhin, V. S. Kashikhin, A. L. Klebaner, G. F. Kuznetsov, G. V. Romanov, A. V. Shemyakin, D. Sun, K. Yonehara, A. V. Zlobin
    Fermilab, Batavia, Illinois
  • L. Thorndahl
    CERN, Geneva
 
  A helical cooling channel (HCC) consisting of a pressurized gas absorber imbedded in a magnetic channel that provides solenoidal, helical dipole and helical quadrupole fields has shown considerable promise in providing six-dimensional cooling for muon beams. The energy lost by muons traversing the gas absorber needs to be replaced by inserting RF cavities into the lattice. Replacing the substantial muon energy losses using RF cavities with reasonable gradients will require a significant fraction of the channel length be devoted to RF. However, to provide the maximum phase space cooling and minimal muon losses, the helical channel should have a short period and length. In this paper we shall examine three approaches to include RF cavities into the HCC lattice:
  1. Use higher frequency cavities that can be placed inside the magnetic channel,
  2. Interleave cavities between magnetic coil rings, and
  3. Place banks of RF cavities between segments of HCC channels.
Each of these approaches has positive and negative features that need to be evaluated in selecting the proper concept for including RF into the HCC system.
 
THPC110 Investigation of Helical Cooling Channel 3233
 
  • K. Yonehara, V. Balbekov
    Fermilab, Batavia, Illinois
 
  A helical cooling channel (HCC) has been proposed to quickly reduce phase space of muon beams*. It is composed of solenoidal and helical coils to provide focusing and dispersion needed for the six-dimension cooling. A comprehensive investigation of the HCC is performed in presented work including theoretical analysis, particle tracking and Monte Carlo simulation. These results are also compared with the past simulation results** to confirm the helical cooling theory. Optimization of the channel and estimation of its ultimate performances are presented.

*Y. Derbenev and R. P. Johnson. PRSTAB 8, 041002 (2005).
**K. Yonehara et al. TPPP052, Particle Accelerator Conference 2005.