Reaching muon collider target emittances by ionization cooling
In plain words
Muons must be squeezed in phase space by a factor of about a million within microseconds, by passing them through absorbers and re-accelerating them; the full chain has never been built.
Precise statement
Transverse ionization cooling of muons through a single absorber was demonstrated by MICE (published 2020). Determine whether a realistic 6D cooling channel plus final cooling stage can reach normalized transverse emittance of approximately 2.5e-3 cm and longitudinal emittance of approximately $7\,\mathrm{cm}$ with overall muon transmission above $\sim 10$ percent, including RF limits in solenoid fields, absorber heating, space charge and muon decay.
What would settle it
An end-to-end simulation with engineering-feasible fields and gradients reaching both emittances, confirmed by a 6D cooling demonstrator for the first stages.
Related problems
- More general than Can final cooling reach collider transverse emittance with acceptable longitudinal growth