• S.A. Kahn, R.J. Abrams, C.M. Ankenbrandt, M.A.C. Cummings, R.P. Johnson, T.J. Roberts
  Muons, Inc, Batavia
• K. Yonehara
  Fermilab, Batavia

Funding: Supported in part by USDOE STTR Grant DE-FG02-06ER86282

The MANX experiment is to demonstrate the reduction of 6D muon phase space emittance using a continuous liquid absorber to provide ionization cooling in a helical solenoid magnetic channel. The experiment involves the construction of a short two-period long helical cooling channel (HCC) to reduce the muon invariant emittance by a factor of two. The HCC would replace the current cooling section of the MICE experiment now being setup at the Rutherford Appleton Laboratory. The MANX experiment would use the existing MICE spectrometers and muon beam line. This paper shall consider the various approaches to integrate MANX into the RAL hall using the MICE spectrometers. This study shall discuss the matching schemes used to minimize losses and prevent emittance growth between the MICE spectrometers and the MANX HCC. Also the placement of additional detection planes in the matching region and the HCC to improve the resolution will be examined.

• T.J. Roberts
  Muons, Inc, Batavia
• D.M. Kaplan
  Illinois Institute of Technology, Chicago, Illinois

Funding: Work supported in part by USDOE STTR Grant DE FG02 08ER86281.

We describe an approach that can extend the utility of frictional cooling, originally developed for muon beams, to other particles and ions, producing beams of exceptionally low normalized emittance. Moreover, via this approach the small momentum acceptance typical of frictional cooling channels can be increased by two to three orders of magnitude, making it possible to handle much larger intensities with much higher transmission, while preserving the exceptionally low normalized emittance of the output. Simulation studies have been used to optimize the design and performance for a variety of ions and particles, and an inexpensive experiment has been designed to test and verify the concept and simulations, using alpha particles from a radioactive source.

• D. Huang
  IIT, Chicago, Illinois
• D.M. Kaplan
  Illinois Institute of Technology, Chicago, Illinois
• K.Y. Ng
  Fermilab, Batavia
• T.J. Roberts
  Muons, Inc, Batavia

Funding: Supported in part by USDOE Contract DE-FG02-6ER86281

The study of Muon beam optics is crucial for future Neutrino Factory and Muon Collider facilities. At present, the GEANT4-based simulation tools for Muon beam tracking such as G4beamline and G4MICE are based on single particle tracking without collective effects taken into account. However, it is known that collective effects such as space charge and wakefields for muons (in matters or vacuum) are not ignorable. As the first step, space charge computation has been implemented into muon tracking. The basic algorithm is particle to particle interactions through retarded electro-magnetic fields. The momentum impulse by collective effects is imposed on every particle at each collective step, and the G4beamline main code is used for tracking. Comparisons to LANL Parmela are illustrated and analyzed. Optimizations of the algorithm are also underway to gain less computing time and more accuracy. Moreover, the idea of enhancing ionization cooling efficiency by utilizing the collective effect due to polarized charges in matter appears to be possible, and the preliminary estimation has been done.

• K.B. Beard, T.J. Roberts
  Muons, Inc, Batavia

Funding: Supported in part by USDOE Contract DE-FG02-6ER86281.

The G4beamline program is based on the well-established Geant4 toolkit used to simulate the interactions of particles and photons with matter. Until now, only a single particle at a time could be tracked and there are no interactions between particles. Recent designs for high pressure RF cavities and other novel devices achieving extreme muon cooling require that the effect of space charge be included in the simulations. A new tracking manager in G4beamline propagates a number of particles (typically 1,000-10,000) in parallel, stepping all particles in time. This allows all of the usual Geant4 physics interactions to be applied, plus collective computations. A simple macroparticle-based model is used to represent ~10⁸ charges with an ellipsoidal charge density. At intervals the appropriate macroparticle size and shape are recalculated, the electric and magnetic fields are determined, and an impulse is applied to the simulated particles. Comparisons to standard space charge codes are presented.

• T.J. Roberts
  Muons, Inc, Batavia
• R.C. Fernow
  BNL, Upton, Long Island, New York

Funding: Work supported in part by USDOE STTR Grant DE-FG02-08ER86281 and DE AC02 98CH10886.

The U.S. muon collider community is mobilizing itself to produce a “Design Feasibility Study” (DFS) for a muon collider. This is happening on an aggressive schedule and must include the best possible simulations to support and validate the technical design. The DFS for a muon collider will require innovative new approaches to many aspects of accelerator design, and the simulations to support it will require tools with features and capabilities that are equally innovative and new. Two computer programs have emerged as the preferred and most commonly used simulation tools within the muon collider community: ICOOL (primary author: Dr. Fernow), and G4beamline (primary author: Dr. Roberts). We describe the ongoing development and testing of both tools for the DFS, including a common suite of tests to ensure that both tools give accurate and realistic results, as well as innovative user-friendly interfaces with emphasis on graphical user interfaces and windows.

• T.J. Roberts, K.B. Beard
  Muons, Inc, Batavia
• S. Ahmed, D.M. Kaplan, L.K. Spentzouris
  Illinois Institute of Technology, Chicago, Illinois
• D. Huang
  IIT, Chicago, Illinois

Funding: Supported in part by USDOE STTR Grant DE-FG02-06ER86281

Most computer programs that calculate the trajectories of particles in accelerators assume that the particles travel in an evacuated chamber. The development of muon beams, which are needed for muon colliders and neutrino factories and are usually required to pass through matter, is limited by the lack of user-friendly numerical simulation codes that accurately calculate scattering and energy loss in matter. Geant4 is an internationally supported tracking toolkit that was developed to simulate particle interactions in large detectors for high energy physics experiments, and includes most of what is known about the interactions of particles and matter. Geant4 has been partially adapted in a program called G4beamline to develop muon beam line designs. The program is now being developed and debugged by a larger number of accelerator physicists studying muon cooling channel designs and other applications. Space-charge effects and muon polarization are new features that are being implemented.

• T.J. Roberts, R.J. Abrams, V. Ivanov
  Muons, Inc, Batavia
• H.J. Frisch
  Enrico Fermi Institute, University of Chicago, Chicago, Illinois

Many measurements in particle and accelerator physics are limited by the time resolution with which individual particles can be detected. This includes particle identification via time-of-flight in major experiments like CDF at Fermilab and Atlas and CMS at the LHC, as well as the measurement of longitudinal variables in accelerator physics experiments. Large-scale systems, such as neutrino detectors, could be significantly improved by inexpensive, large-area photo detectors with resolutions of a few millimeters in space and a few picoseconds in time. Recent innovations make inexpensive, large-area detectors possible, with only minor compromises in spatial and time resolution. The G4beamline program [1] is one of the appropriate tools for simulation of low-energy physics processes. The set of specialized tools - MCPS [2], POISSON-2 [3] and Monte Carlo Simulator was used for numerical study of different photo multipliers.