A Design for a 3 TeV Rapid Cycling Synchrotron for Muon Acceleration in the SPS Tunnel

Current proposals for new high-energy physics machines either focus on building ever-larger circular hadron colliders, such as the proposed FCC- hh, or on electron-positron linac designs, such as CLIC and ILC. However, muon colliders present an alternative approach to probing new physics at the energy frontier while also offering a number of advantages over hadron or electron-positron colliders. A detailed design for the acceleration stage of a future 3 TeV centre of mass energy muon collider is proposed. The acceleration of muons to 1.5 TeV would be achieved in two hybrid Rapid Cycling Synchrotrons (RCSs), which would both be situated in the existing SPS tunnel at CERN. RCS1 would accelerate counter rotating muons and antimuons from 100 GeV to 900 GeV before they would be injected into RCS2 where they would then be accelerated up to 1.5 TeV. The lattice design was optimised to fit into the SPS tunnel and two dispersion suppressor schemes are presented. Longitudinal simulations were performed in order to study beam loss and collective effects over the acceleration cycle. A radiofrequency cavity was designed, where the optimal frequency and cavity geometry were investigated, before being modelled in 3D. Designs for the normal conducting dipoles and quadrupoles are presented, which meet the requirements detailed in the lattice design while also minimising power consumption. Radiation deposition in the accelerator was also investigated, along with a study on the environmental exposure from neutrino radiation.