• R.C. Fernow, J.C. Gallardo
  BNL, Upton, Long Island, New York

Using muons instead of electrons is a promising approach to designing a lepton-lepton collider with energies beyond that available at the proposed ILC. At this time a self-consistent design of a high-luminosity muon collider has not been completed. However, a lot of progress has been made in simulating cooling and parts of other systems that could play a role in an eventual collider design. In this paper we look at front-end system designs that begin with a single pion bunch produced from a high power mercury target. We present ICOOL simulation results for phase rotation, charge separation, and pre-cooling of the muon beams. A design is presented for a single-frequency phase rotation system that can transmit 0.47 muons per incident proton on the target. A bent solenoid can be used for high-efficiency separation of the positive and negative muon beams.

• R.C. Fernow
  BNL, Upton, Long Island, New York

Current ideas for designing neutrino factories and muon colliders require unique configurations of fields and materials to prepare the muon beam for acceleration. We have continued the development of the 3D tracking code ICOOL for examining possible system configurations. Development of the ICOOL code began in 1996 in order to simulate the process of ionization cooling. This required tracking in magnetic focusing lattices, together with interactions in shaped materials that must be placed in the beam path.* The most important particle interactions that had to be simulated were energy loss and straggling. Since the optimum way of designing a cooling channel was not known, the code had to have a flexible procedure for specifying field and material geometries. Eventually the early linear cooling channels evolved into cooling rings. In addition the designs require many other novel beam manipulations besides ionization cooling, such as pion collection in a high field solenoid, rf phase rotation, and acceleration in FFAG rings. We describe new features that have been incorporated in ICOOL for handling these new requirements. A suite of auxilliary codes have also been developed for pre-processing, post-processing, and optimization.

*R.C. Fernow, ICOOL: a simulation code for ionization cooling of muon beams, Proc. 1999 Part. Accel. Conf., New York, p. 3020.

• J.C. Gallardo, J.S. Berg, R.C. Fernow, H.G. Kirk, R. Palmer
  BNL, Upton, Long Island, New York
• D.V. Neuffer
  Fermilab, Batavia, Illinois
• K. Paul
  Muons, Inc, Batavia

As part of the APS Joint Study on the Future of Neutrino Physics* we have carried out detailed studies of the Neutrino Factory front-end. A major goal of the new study was to achieve equal performance to our earlier feasibility studies** at reduced cost. The optimal channel design is described in this paper. New innovations included an adiabatic buncher for phase rotation and a simplified cooling channel with LiH absorbers. The linear channel is 295 m long and produces 0.17 muons per proton on target into the assumed accelerator transverse acceptance of 30 mm and longitudinal acceptance of 150 mm.

*APS Multi-Divisional Study of the Physics of Neutrinos, http://www.aps.org/neutrino/. **S.Ozaki, R.B.Palmer, M.Zisman and J.C.Gallardo, edts., Tech. Rep., BNL-52623 (2001), http://www.cap.bnl.gov/mumu/studyii/FS2-report.html.