Can final cooling reach collider transverse emittance with acceptable longitudinal growth? · revision history

Revision 2

Accepted · core change · record

Changes against revision 1:

Title · changed
Revision 1: Can final cooling reach collider transverse emittance with acceptable longitudinal growth
Revision 2: Can final cooling reach collider transverse emittance with acceptable longitudinal growth?
Plain
The last cooling stage must reduce the beam width to about 25 microns while letting it spread lengthwise only within a set limit. No design has yet met both goals together.
Precise · changed · core
Revision 1: Muon collider design studies (MAP, the US Muon Accelerator Program, then IMCC, the International Muon Collider Collaboration) set normalized emittance targets of about eps_T ~ 22.5 to 25 micron transverse and eps_L ~ 70 mm (7.5 MeV m) longitudinal at the end of cooling. Determine whether a final-cooling channel using very high field solenoids ($B \sim 300 \text{ to } 400\,\mathrm{kG}$) or thick wedge absorbers reaches eps_T <= 25 micron with eps_L <= 75 mm and muon transmission above $\sim 50\,\mathrm{percent}$, including decay losses.
Revision 2: Muon collider design studies (MAP, the US Muon Accelerator Program, then IMCC, the International Muon Collider Collaboration) set normalized emittance targets of about eps_T ~ 22.5 to 25 micron transverse and eps_L ~ 70 mm (7.5 MeV m) longitudinal at the end of cooling. Determine whether a final-cooling channel using very high field solenoids ($B \sim 300 \text{ to } 400\,\mathrm{kG}$) or thick wedge absorbers reaches eps_T <= 25 micron with eps_L <= 75 mm and muon transmission above $\sim 50\%$, including decay losses.
Settled by
End-to-end tracking of a realistic final-cooling lattice with engineering-feasible magnets meeting the targets, later confirmed by a demonstrator.
Kind
well-posed
Answer type
yes-no
References
(empty)
Literature status
open
Status note
Thick-wedge final-cooling designs (2024) and a 2026 dispersion-suppressor study for them aim at the 22 micron transverse target; meeting both targets in one realistic lattice is not yet shown.
Posed since
(empty)

Decisions