6D muon ionization cooling problems are discussed in the context of Muon Collider-Neutrino Factory project including:
- Muon Collider outline by MCAC.
- A little about physics of 6D ionization cooling.
- Brief survey of 6D cooling facilities: Ring Coolers, ”Guggenheim”, HCC, RFOFO Snake, etc.
- More about the rectilinear cooling channel with tilted solenoids.
It is shown that the channel meets the requirements of low energy Higgs factory.
Pros, cons and problems.