Author: Yoshikawa, C. Y.
Paper Title Page
MOPPC034 Use of Helical Transport Channels for Bunch Recombination 205
 
  • D.V. Neuffer, K. Yonehara
    Fermilab, Batavia, USA
  • C.M. Ankenbrandt, C. Y. Yoshikawa
    Muons, Inc, Batavia, USA
 
  Cooling scenarios for a high-luminosity Muon Collider require bunch recombination for optimal luminosity. In this paper we describe a new method for bunch recombination. We combine the high-chronicity of a helical transport channel (HTC) with the high-frequency bunching and phase-energy rotation concept (time-reversed) to obtain a compact bunch recombination system adapted to a muon collider scenario. We first present an idealized 1-D system with multiple chronicity transports. We then implement the concept in a single-chronicity channel, obtaining bunch recombination of 13 200MHz-spaced bunches to a single collider-ready bunch within a compact transport with modest rf requirements. That example is demonstrated within G4BL 3-D simulations. Variations and adaptations for different recombination requirements are discussed.  
 
MOPPD043 Novel Muon Beam Facilities for Project X at Fermilab 457
 
  • C.M. Ankenbrandt, R.J. Abrams, T.J. Roberts, C. Y. Yoshikawa
    Muons, Inc, Batavia, USA
  • D.V. Neuffer
    Fermilab, Batavia, USA
 
  Innovative muon beam concepts for intensity-frontier experiments such as muon-to-electron conversion are described. Elaborating upon a previous single-beam idea, we have developed a design concept for a system to generate four high quality, low-energy muon beams (two of each sign) from a single beam of protons. As a first step, the production of pions by 1 and 3 GeV protons from the proposed Project X linac at Fermilab is being simulated and compared with the 8-GeV results from the previous study.  
 
MOPPD044 Optimization of the Target Subsystem for the New g-2 Experiment 460
 
  • C. Y. Yoshikawa, C.M. Ankenbrandt
    Muons, Inc, Batavia, USA
  • A.F. Leveling, N.V. Mokhov, J.P. Morgan, D.V. Neuffer, S.I. Striganov
    Fermilab, Batavia, USA
 
  A precision measurement of the muon anomalous magnetic moment, aμ = (g-2)/2, was previously performed at BNL with a result of 2.2 - 2.7 standard deviations above the Standard Model (SM) theoretical calculations. The same experimental apparatus is being planned to run in the new Muon Campus at Fermilab, where the muon beam is expected to have less pion contamination and the extended dataset may provide a possible 7.5σ deviation from the SM, creating a sensitive and complementary benchmark for proposed SM extensions. We report here on a preliminary study of the target subsystem where the apparatus is optimized for pions that have favorable phase space to create polarized daughter muons around the magic momentum of 3.094 GeV/c, which is needed by the downstream g 2 muon ring.  
 
TUPPD006 IDR Neutrino Factory Front End and Variations 1416
 
  • D.V. Neuffer
    Fermilab, Batavia, USA
  • A. Alekou
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  • C.T. Rogers
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  • P. Snopok
    IIT, Chicago, Illinois, USA
  • C. Y. Yoshikawa
    Muons, Inc, Batavia, USA
 
  The (International Design Report) IDR neutrino factory scenario for capture, bunching, phase-energy rotation and initial cooling of muons produced from a proton source target is presented. It requires a drift section from the target, a bunching section and a phase-energy rotation section leading into the cooling channel. The rf frequency changes along the bunching and rotation transport in order to form the muons into a train of equal-energy bunches suitable for cooling and acceleration. This design is being explored within the IDR cost model. Important concerns are rf limitations and beam losses. Recent experiments on rf gradient limits suggest preferred configurations for the rf within the magnetic fields, and these considerations are incorporated into the front end design.  
 
TUPPD012 Complete Muon Cooling Channel Design and Simulations 1431
 
  • C. Y. Yoshikawa, C.M. Ankenbrandt, R.P. Johnson
    Muons, Inc, Batavia, USA
  • Y.S. Derbenev, V.S. Morozov
    JLAB, Newport News, Virginia, USA
  • D.V. Neuffer, K. Yonehara
    Fermilab, Batavia, USA
 
  Considerable progress has been made in developing promising subsystems for muon beam cooling channels to provide the extraordinary reduction of emittances required for an energy-frontier muon collider. However, it has not yet been demonstrated that the various proposed cooling subsystems can be consolidated into an integrated end-to-end design. Presented here are concepts to address the matching of transverse emittances between subsystems through an extension of the theoretical framework of the Helical Cooling Channel (HCC), which allows a general analytical approach to guide the transition from one set of cooling channel parameters to another.  
 
TUPPD013 Bunch Coalescing in a Helical Channel 1434
 
  • C. Y. Yoshikawa, C.M. Ankenbrandt
    Muons, Inc, Batavia, USA
  • D.V. Neuffer, K. Yonehara
    Fermilab, Batavia, USA
 
  Funding: Supported in part by SBIR Grant 4725 · 09SC02739.
A high-luminosity Muon Collider requires bunch recombination for optimal luminosity. In this paper, we take advantage of the large slip factor in a helical transport channel (HTC) to coalesce bunches of muons into a single one over a shorter distance than can be achieved over a straight channel. The coalescing subsystem that is designed to merge 9 bunches has a horizontal length of ~105m and is able to achieve efficiencies of 99.7%, 98.4%, and 94.2% for 9, 11, and 13 bunches, respectively, where each bunch has emittances expected at the end of an HCC. Simplified designs incorporating fill factors for RF cavities of ~25% and ~50% obtained efficiencies of 96%, 94-95%, and 90-91% for 9, 11, and 13 bunches, respectively. The efficiencies above do not include decay losses, which would be ~8% for muons with kinetic energy of 200 MeV.
 
 
TUPPD033 Conceptual Design of a Positron-annihilation System for Generation of Quasi-monochromatic Gamma Rays 1476
 
  • R.J. Abrams, C.M. Ankenbrandt, K.B. Beard, G. Flanagan, R.P. Johnson, C. Y. Yoshikawa
    Muons, Inc, Batavia, USA
  • A. Afanasev
    GWU, Washington, USA
 
  A conceptual design is presented for a system consisting of the following: an electron accelerator and production target to produce positrons, a dipole magnet and wedge to compress the positron momenta to be nearly monochromatic, a magnetic transport system to focus and direct the positrons to a converter, and a converter in which the positrons annihilate in flight to produce quasi-monochromatic gamma rays. The system represented is designed to produce ~10 MeV gammas, but it can also be designed for other energies.