Six-Dimensional Beam Cooling in a Gas Absorber

72180B03-I Future energy-frontier accelerators depend on the development of robust and affordable techniques to quickly reduce the size of a muon beam. Although schemes exist for reducing horizontal and vertical muon beam dimensions, there are no satisfactory engineering solutions for quickly shrinking the beam bunch length or momentum spread. Gas-filled, high-gradient radio frequency (RF) cavities, operating in a superimposed linear magnetic channel of combined solenoidal and dipole fields, offer the potential to provide simultaneous muon beam cooling in all six dimensions. This project will use analytical and simulation techniques to develop such a channel and will design and prototype the critical components needed for a muon beam demonstration experiment. Phase I will design a linear, six-dimensional muon cooling channel with a gaseous absorber and high-gradient, pressurized RF cavities, optimized by computer simulations to be superior to the ring coolers presently under development. Critical technical issues will be identified for computational and experimental investigation in Phase II. Commercial Applications and Other Benefits as described by awardee: The six-dimensional cooling channel should be relatively short by virtue of the high RF gradient, have no space unoccupied by RF, and be very efficient. Such a channel would help make Neutrino Factories affordable and Muon Colliders compelling.