Final Cooling With Thick Wedges for a Muon Collider

TL;DR

This paper proposes a new design for the final cooling stage of a muon collider using dense wedge absorbers, achieving better transverse and longitudinal emittance reduction than previous methods.

Contribution

It introduces a novel conceptual design for the final 4D muon cooling channel based on dense wedge absorbers, optimized through simulations.

Findings

Achieves transverse cooling factor of approximately 3.5 in both x and y directions.

Produces lower transverse and longitudinal emittance than previous designs.

Uses G4Beamline and Python for simulation and analysis.

Abstract

In the final cooling stages for a muon collider, the transverse emittances are reduced while the longitudinal emittance is allowed to increase. In previous studies, Final cooling used absorbers within very high field solenoids to cool low-momentum muons. Simulations of the systems did not reach the desired cooling design goals. In this study, we develop and optimize a different conceptual design for the final 4D cooling channel, which is based on using dense wedge absorbers. We used G4Beamline to simulate the channel and Python to generate and analyze particle distributions. We optimized the design parameters of the cooling channel and produced conceptual designs (corresponding to possible starting points for the input beam) which achieve transverse cooling in both x and y by a factor of $\approx$ 3.5. These channels achieve a lower transverse and longitudinal emittance than the best previously published design.