Gaseous H2 Absorber for Muon Beam Cooling

75498-Ionization cooling, a method for shrinking the size of a particle beam, is an essential technique for future particle accelerators that use muons. Muon colliders and neutrino factories, examples of these future accelerators, depend on the development of robust and affordable techniques for ionization cooling. Unlike schemes now under consideration, which are based on using many large flasks of a liquid hydrogen energy-absorber, the use of a gas absorber could lead to a simpler design with better cooling. Another advantage would be the potential for much higher accelerating gradients. This project will design an ionization-cooling channel based on a gaseous absorber and develop a prototype channel section suitable for testing in a muon beam. Phase I will produce a baseline conceptual design of a muon ionization-cooling channel, with gaseous absorber and high-gradient pressurized RF cavities, which has been optimized by computer simulations to be superior to those based on liquid absorbers. Critical technical issues will be identified for computational and experimental investigation in Phase II. Commercial Applications and Other Benefits as described by the awardee: Cooling and accelerating muons using a gaseous absorber and pressurized high-gradient RF cavities could help make neutrino factories affordable and muon colliders a compelling option. The estimated cost of the transverse ionization-cooling component of each muon collider or neutrino factory is roughly $350 million; the use of a gaseous energy absorber could cut the cost of the cooling channel in half.