MSU, East Lansing, Michigan, USA
Fermilab, Batavia, Illinois, USA
JLab, Newport News, Virginia, USA
BNL, Upton, Long Island, New York, USA
Fermilab, Batavia, Illinois, USA
Illinois Institute of Technology, Chicago, Illinois, USA
We describe a muon capture section to manipulate the longitudinal and transverse phase-space so that to collect efficiently a muon beam produced from an intense proton source target. We show that this can be achieved by using a set of properly tuned rf cavities that captures the beam into string of bunches and aligns them into nearly equal central energies, and a solenoidal chicane that filters high momentum particles, followed by a proton absorber that reduces the energy of all particles. This work elucidates the key parameters that are needed for successful muon capture, such as the required rf frequencies, rf gradients and focusing field. We discuss the sensitivity in performance against the number of different rf frequencies and accelerating rf gradient.
Illinois Institute of Technology, Chicago, Illlinois, USA
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
Fermilab, Batavia, Illinois, USA
The Muon Ionization Cooling Experiment (MICE) at the Rutherford Appleton Laboratory aims to demonstrate ~10% ionization cooling of a muon beam, by its interaction with low-Z absorber materials followed by restoration of longitudinal momentum in RF linacs. MICE Step V will provide the flexibility for a thorough exploration and characterization of the performance of ionization cooling. Step V will include four RF cavities to provide 8 MV/m gradient in a strong magnetic field. This entails an RF drive system to deliver 2 MW, 1 ms pulses of 201 MHz frequency at 1 Hz repetition rate, the distribution network to deliver 1 MW to each cavity with correct RF phasing, diagnostics to determine the gradient and the muon transit phase, and development of the large diameter magnets required in order to keep the muons focused through the linacs. Progress towards the completion of Step V is described.
IIT, Chicago, Illinois, USA
Sheffield University, Sheffield, United Kingdom
The International Muon Ionization Cooling Experiment will provide the demonstration ionization cooling. The experiment is being built in a series of Steps. Step IV, which consists of a tracking spectrometer upstream and downstream of an absorber/focus-coil (AFC) module will be completed in early in 2015. In this configuration, the emittance of the muon beam upstream and downstream of the absorber will be measured precisely allowing the emittance reduction and the factors that determine the ionization cooling effect to be studied in detail. The AFC module is a 22 liter volume of liquid hydrogen placed inside a superconducting focusing coil. The properties of lithium hydride, and possibly other absorber materials, will also be studied. All the components of Step IV have been manufactured and integration of the experiment in the MICE Hall at the Rutherford Appleton Laboratory is underway. A full study of ionization cooling will be carried out with Step V, which will include a short 201 MHz linac module in which beam transport is achieved with a superconducting “coupling coil”. The status of the preparation of the components of Step V of the experiment will be described briefly.
Illinois Institute of Technology, Chicago, Illlinois, USA
Indiana University South Bend, South Bend, USA
Fermilab, Batavia, Illinois, USA
IIT, Chicago, Illinois, USA
Current designs for muon cooling channels require high-gradient RF cavities to be placed in solenoidal magnetic fields in order to contain muons with large transverse emittances. It has been found that doing so reduces the threshold at which RF cavity breakdown occurs. To aid the effort to study RF cavity breakdown in magnetic fields it would be helpful to have a diagnostic tool which can detect breakdown and localize the source of the breakdown inside the cavity. We report here on the experiment setup for localizing sparks in an RF cavity by using piezoelectric transducers and on preparation for data collection on a 201.25 MHz vacuum cavity.
IIT, Chicago, Illinois, USA
MSU, East Lansing, Michigan, USA
Illinois Institute of Technology, Chicago, Illlinois, USA
COSY Infinity is an arbitrary-order beam dynamics simulation code. It can determine high-order transfer maps of combinations of particle optical elements. New features are being developed for inclusion in COSY to follow the distribution of particles through matter. To study in detail the properties of muons passing through material, the transfer map approach alone is not sufficient. The interplay of beam optics and atomic processes must be studied by a hybrid transfer map–Monte-Carlo approach in which transfer map methods describe the average behavior of the particles including energy loss, and Monte-Carlo methods are used to provide small corrections to the predictions of the transfer map accounting for the stochastic nature of scattering and straggling of particles. The advantage of the new approach is that the vast majority of the dynamics is represented by fast application of the high-order transfer map of an entire element and accumulated stochastic effects. The gains in speed will aid the optimization of muon cooling channels. Progress on the development of the required algorithms is reported.
BNL, Upton, Long Island, New York, USA
Fermilab, Batavia, Illinois, USA
Illinois Institute of Technology, Chicago, Illinois, USA
In Muon Accelerators muons are produced by impacting high energy protons onto a target to produce pions. The pions decay to muons which are then accelerated. Through this process a significant background of protons and electrons are generated, which may result in heat deposition on superconducting materials and activation of the machine. In this paper we propose a two-step particle selection scheme: a chicane to remove the high momentum particles from the beam and a Beryllium block absorber that reduces momentum of all particles in the beam, resulting in the loss of low momentum protons. We review the design and numerically examine its impact on the performance of the muon front-end.
SLAC, Menlo Park, California, USA
Fermilab, Batavia, Illinois, USA
JLab, Newport News, Virginia, USA
Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
Illinois Institute of Technology, Chicago, Illinois, USA
BNL, Upton, Long Island, New York, USA
LBNL, Berkeley, California, USA
Muon-based facilities offer unique potential to provide capabilities at both the Intensity Frontier with Neutrino Factories and the Energy Frontier with Muon Colliders. They rely on a novel technology with challenging parameters, for which the feasibility is currently being evaluated by the Muon Accelerator Program (MAP). A realistic scenario for a complementary series of staged facilities with increasing complexity and significant physics potential at each stage has been developed. It takes advantage of and leverages the capabilities already planned for Fermilab, especially the strategy for long-term improvement of the accelerator complex being initiated with the Proton Improvement Plan (PIP-II) and the Long Baseline Neutrino Facility (LBNF). Each stage is designed to provide an R&D platform to validate the technologies required for subsequent stages. The rationale and sequence of the staging process and the critical issues to be addressed at each stage, are presented.
