Extreme Beams and Other Technologies

4B - Muon Linacs

Paper Title Page
MOP064 Bent Solenoid Tuning Simulations for the COMET Beamline 226
  • A. Kurup
    Imperial College of Science and Technology, Department of Physics, London

The COMET experiment beamline uses bent solenoids for the muon transport and the spectrometer used to analyse the decay electrons from stopped muons. The bent solenoid includes not just a solenoid field but also a vertical dipole field. It is therefore important to have the ability to tune the field distribution. However, since the field distribution is mainly determined by the geometry it is difficult to adjust once the solenoids have been constructed. A cost effective method to provide tuning capability of the field distribution of the bent solenoids is proposed and the results of simulations presented.

MOP066 Status of MICE: the International Muon Ionization Cooling Experiment 229
  • D. Huang
    IIT, Chicago, Illinois
  • D.M. Kaplan
    Illinois Institute of Technology, Chicago, Illinois
  • M.S. Zisman
    LBNL, Berkeley, California

Funding: This work was partially supported by the Office of Science, U. S. Department of Energy, under Contract No. DE-AC02-05CH11231.
A key unanswered question in particle physics is why the universe consists only of matter. It is believed that CP violation in the lepton sector is the answer. The best tool to find this is a muon-based Neutrino Factory. Muons can also be used for an energy-frontier collider that would fit on an existing laboratory site. Since muons are produced as a tertiary beam, their phase space and energy spread are large and must be reduced (cooled) to create a usable beam. Ionization cooling, comprising momentum loss in material followed by rf reacceleration, is the only suitable technique. A cooling channel is merely a linac with absorbing material in the beam path. To demonstrate an understanding of the physics and technology issues, MICE will test a section of cooling channel exposed to a muon beam derived from the ISIS synchrotron at RAL. The muon beam line is now installed and commissioning is under way. Fabrication of cooling channel components and the required detector systems has begun and will be described. A successful demonstration will go a long way toward proving the value of muon beams for future accelerator-based particle physics experiments.

FR202 Linacs for Future Muon Facilities 1119
  • S.A. Bogacz
    JLAB, Newport News, Virginia
  • R.P. Johnson
    Muons, Inc, Batavia

Funding: Supported in part by DOE STTR grant DE-FG02-05ER86253
Neutrino Factories and Muon Colliders require rapid acceleration of short-lived muons to multi-GeV and TeV energies. A Recirculated Linear Accelerator (RLA) that uses a single Linac and teardrop return arcs (the so called 'Dogbone' RLA) can provide exceptionally fast and economical acceleration to the extent that the focusing range of the RLA quadrupoles allows each muon to pass several times through each high-gradient cavity. Since muons are generated as a tertiary beam they occupy large phase-space volume and the accelerator must provide very large transverse and longitudinal acceptances. The above requirements drive the design to low rf frequency. A new concept of rapidly changing the strength of the RLA focusing quadrupoles as the muons gain energy is being developed to increase the number of passes that each muon will make in the rf cavities, leading to greater cost effectiveness. We are developing the optics and technical requirements for RLA designs, using superconducting rf cavities capable of simultaneous acceleration of both μ+ and μ- species, with pulsed Linac quadrupoles to allow the maximum number of passes.


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