Frictional Cooling Scheme for Use in a Muon Collider

Abstract

Abstract. The Muon Group at the MPI for Physics, Munich is investigating frictional cooling as a fast muon-beam emittance reduction scheme for a muon collider. A new simulation package, CoolSim, based on Geant4 has been developed for the simulation of low-energy beam cooling. New physics processes for low energy muons and protons have been implemented in the Geant4 framework. The group's Frictional Cooling Demonstration experiment aims to verify the principle of the cooling scheme. For this purpose, a 10-cm-long cooling cell has been constructed to test simulation of the energy loss and scattering mechanisms at low energy. This paper contains an introduction to a muon-collider frictional cooling scheme and the status of the demonstration experiment.

Development of a Frictional Cooling Demonstration experiment

“…We simulated the frictional cooling process in the fcd cell to provide expectations for proton energy spectra under different configurations. For this simulation as well as full frictional cooling schemes [21,22], we developed software based on Geant4, called CoolSim [23]. It implements the low-energy packages of Geant4 optimized for the tracking of protons and muons through matter.…”

“…It implements the low-energy packages of Geant4 optimized for the tracking of protons and muons through matter. As well, we have added new processes to the Geant4 framework for the simulation of charge exchange processes at low energies in gaseous materials [21].…”

Low-energy μ+ via frictional cooling

“…where σ i j is the cross section for the changing charge state from q i to q j [13]. The effective charges for µ + in helium and carbon are shown in Fig.…”