CERN Accelerating science

Article
Title	Recent Innovations in Muon Beam Cooling and Prospects for Muon Colliders
Author(s)	Johnson, Rolland P ; Alsharo'a, Mohammad ; Ankenbrandt, Charles ; Barzi, Emanuela ; Beard, Kevin ; Bogacz, S A ; Del Frate, Licia ; Derbenev, Yaroslav S ; Gonin, Ivan V ; Hanlet, Pierrick M ; Hartline, Robert ; Kaplan, Daniel ; Kuchnir, Moyses ; Moretti, Alfred ; Neuffer, David V ; Paul, Kevin ; Popovic, Milorad ; Roberts, Thomas ; Romanov, Gennady ; Turrioni, Daniele ; Yarba, Victor ; Yonehara, Katsuya
Affiliation	(Fermilab, Batavia, Illinois) ; (Illinois Institute of Technology, Chicago, Illinois) ; (Jefferson Lab, Newport News, Virginia) ; (Muons, Inc, Batavia)
Publication	2005
In:	21st IEEE Particle Accelerator Conference, Knoxville, TN, USA, 16 - 20 May 2005, pp.419
Subject category	Accelerators and Storage Rings
Abstract	A six-dimensional(6D)cooling channel based on helical magnets surrounding RF cavities filled with dense hydrogen gas* is used to achieve the small transverse emittances demanded by a high-luminosity muon collider. This helical cooling channel**(HCC) has solenoidal, helical dipole, and helical quadrupole magnetic fields to generate emittance exchange. Simulations verify the analytic predictions and have shown a 6D emittance reduction of over 3 orders of magnitude in a 100 m HCC segment. Using three such sequential HCC segments, where the RF frequencies are increased and transverse dimensions reduced as the beams become cooler, implies a 6D emittance reduction of almost six orders of magnitude. After this, two new post-cooling ideas can be employed to reduce transverse emittances to one or two mm-mr, which allows high luminosity with fewer muons than previously imagined. In this report we discuss the status of and the plans for the HCC simulation and engineering efforts. We also describe the new post-cooling ideas and comment on the prospects for a Higgs factory or energy frontier muon collider using existing laboratory infrastructure.