• A.D. Bross, S. Geer, V.D. Shiltsev
  Fermilab, Batavia
• H.G. Kirk
  BNL, Upton, Long Island, New York
• Y. Torun
  IIT, Chicago, Illinois
• M.S. Zisman
  LBNL, Berkeley, California

An accelerator complex that can produce ultra-intense beams of muons presents many opportunities to explore new physics. A facility of this type is unique in that, in a relatively straightforward way, it can present a physics program that can be staged and thus move forward incrementally, addressing exciting new physics at each step. At the request of the US Department of Energy's Office of High Energy Physics, the Neutrino Factory and Muon Collider Collaboration and the Fermilab Muon Collider Task Force have recently submitted a proposal to create a Muon Accelerator Program that will have, as a primary goal, to deliver a Design Feasibility Study for an energy-frontier Muon Collider after a 7 year R&D program. This paper presents a description of a Muon Collider facility with a brief physics motivation, gives an overview of the proposal with respect to its organization and timeline and then discusses in some detail its major technical components.

• K.T. McDonald
  PU, Princeton, New Jersey
• J.R.J. Bennett
  STFC/RAL/ASTeC, Chilton, Didcot, Oxon
• O. Caretta, P. Loveridge
  STFC/RAL, Chilton, Didcot, Oxon
• A.J. Carroll, V.B. Graves, P.T. Spampinato
  ORNL, Oak Ridge, Tennessee
• I. Efthymiopoulos, F. Haug, J. Lettry, M. Palm, H. Pereira
  CERN, Geneva
• A. Fabich
  EBG MedAustron, Wr. Neustadt
• H.G. Kirk, H. Park, T. Tsang
  BNL, Upton, Long Island, New York
• N.V. Mokhov, S.I. Striganov
  Fermilab, Batavia
• P.H. Titus
  PPPL, Princeton, New Jersey

We report on the analysis of data collected in the MERIT experiment at CERN during the Fall of 2007. These results validate the concept of a free mercury jet inside a high-field solenoid magnet as a target for a pulsed proton beam of 4-MW power, as needed for a future Muon Collider and/or Neutrino Factory.

• H.G. Kirk
  BNL, Upton, Long Island, New York
• J.J. Back
  University of Warwick, Coventry
• C.J. Densham, P. Loveridge
  STFC/RAL, Chilton, Didcot, Oxon
• X.P. Ding
  UCLA, Los Angeles, California
• V.B. Graves
  ORNL, Oak Ridge, Tennessee
• F. Ladeinde, Y. Zhan
  SUNY SB, Stony Brook, New York
• K.T. McDonald
  PU, Princeton, New Jersey

We outline a program of engineering design and simulation for a target station and pion production/capture system for a 4-MW proton beam at the front end of a Muon Collider or a Neutrino Factory. The target system consists of a free liquid-metal (nominally mercury) jet immersed in a high-field solenoid magnet capture system that also incorporates the proton beam dump. Topics to be studied include optimization of proton beam and jet target parameters, of the magnetic configuration for capture and subsequent transport of pions and muons, of the beam dump, of the radiation/thermal shielding of the capture magnets, and of the beam windows.

• X.P. Ding, D.B. Cline
  UCLA, Los Angeles, California
• J.S. Berg, H.G. Kirk
  BNL, Upton, Long Island, New York

A study of a pion production and capture system for a 4MW target station for a neutrino factory or muon collider is presented. Using the MARS code, we simulate the pion production produced by the interaction of a free liquid mercury jet with an intense proton beam. We study the variation of meson production with the direction of the proton beam relative to the target. We also examine the influence on the meson production by the focusing of the proton beam. The energy deposition in the capture system is determined and the shielding required in order to avoid radiation damage is discussed.