Collective Effects in High-Energy Muon Colliders

Collective single-beam effects, driven by impedances andwake fields in the vacuum chamber of high-energy muon colliders HEMC,are evaluated:<BR>(i) using techniques that have been applied toproton-proton colliders such as the LHC and extrapolations from it,<BR>(ii) using a new technique more applicable to nearly-isochronous HEMC,adding longitudinal and transverse kicks from longitudinal andtransverse loss factors.<BR>Results from both techniques are presentedforHEMC at 10 and 100 TeV centre-of-mass energies.