A summary is given of results from the first year of Muon Collider Task Force activities, together with a description of an updated longer-term R&D plan. In particular, this report summarizes Muon Collider ring and ionization cooling channel design and simulation studies, progress towards testing a high-pressure RF cavity in a beam at the Muon Test Area, Helical Cooling Channel design and simulation studies, progress towards a fourcoil helical solenoid test, design considerations for a 6D cooling experiment, and High Temperature Superconductor magnet and conductor studies for a high field solenoid at the end of a Muon Collider cooling channel.
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Executive SummaryMuon Colliders offer a possible long term path to lepton-lepton collisions at center-ofmass energies s 1 TeV. In October 2006 the Muon Collider Task Force (MCTF) proposed a program of advanced accelerator R&D aimed at developing the Muon Collider concept. The proposed R&D program was motivated by progress on Muon Collider design in general, and in particular, by new ideas that have emerged on muon cooling channel design. The scope of the proposed MCTF R&D program includes muon collider design studies, helical cooling channel design and simulation, high temperature superconducting solenoid studies, an experimental program using beams to test cooling channel RF cavities and a 6D cooling demonstration channel. The first year of MCTF activities are summarized in this report together with a brief description of the anticipated FY08 R&D activities.
Muon Collider Design Studies:An important goal for the MCTF activity is, within the next two to three years, to establish one or more realizable muon collider parameter set(s), and hence identify the performance goals for the muon cooling channel. Past physics studies have shown that a Muon Collider with s = 1 TeV to a few TeV requires a minimum luminosity of ~ 10 34 cm -2 s -1 to probe with adequate sensitivity the physics beyond the Standard Model. Two design strategies are being investigated to achieve this luminosity. In the "high-emittance" strategy the muons of each sign are packaged in the minimum number of bunches (one per cycle) and the emittance goal corresponds to the beam-beam limit. In the "low-emittance" strategy the muons are packaged into many bunches with much lower transverse emittances. To establish the feasibility of the highand/or low-emittance schemes it is necessary to establish the existence of corresponding Collider Lattice designs that assume realistic parameters for magnets, rf, etc. Ring studies this year explored various lattices, paying attention to chromatic correction and momentum acceptance. The designs for the high-emittance lattice are close to achieving the desired momentum acceptance and dynamic aperture, although further studies are needed. However, new ideas are needed to achieve a ring design that corresponds to the low emittance collider scheme.Cooling Channel Design and Simulation: In addition to different collider design strategies (low-or high-emittance), different...