A hybrid six-dimensional muon cooling channel with gas filled cavities

Obtaining the desired micron-scale emittances for a Muon Collider requires transporting the muon beam through long sections of a beam channel containing rf cavities, absorbers, and focusing solenoids. Here we discuss possible implementation of high-pressure gas-filled RF cavities in a 6D ionization cooling channel and some technical issues associated with it. The key idea of our scheme is a hybrid approach that uses high-pressure gas to avoid cavity breakdown, along with discrete LiH absorbers to provide the majority of the energy loss. We show that the channel performs as well as the original vacuum rf channel while potentially avoiding degradation in rf gradient associated with the strong magnetic field in the cooling channel.