Conceptual Design of a Target and Capture Channel for a Muon Collider

The “target and capture channel” is one of the crucial systems in a Muon Collider, whose function is to create an intense muon beam from the decay of the pions generated by a multi-MW proton beam impinging on a particle-producing target. To guarantee the capture of the pions and resulting muons, the channel consists of a sequence of solenoids, providing a well-defined profile on axis, with 20 T peak at the target location and an adiabatic decrease along the channel length. The solenoids of the channel need substantial shielding from the radiation heat load and dose originating from the nuclear interactions at the target, which results in large bore in excess of 1 m. In this paper we describe a concept for the target and capture solenoid, built with modules whose geometry is optimized to produce the required field profile while minimizing the stored magnetic energy of the system. All solenoids are wound with an internally cooled HTS cable. We focus here on the magnetic and mechanical design of the magnets.