Proton beam formation at Fermilab for μ2e (and for NF/MC)

Proton bunch formation from the Fermilab proton sources for the mu2e experiment is discussed. In the initial scenario a single intense h=1 bunch is formed in the Accumulator/Debuncher, with slow extraction providing the required spill. However, the mu2e experiment could use h=4 bunching in the Accumulator rather than h=1, with the 4 bunches fed one at a time into the more isochronous Debuncher for slow extraction. The h=4 variant has several advantages and a few disadvantages, and can reduce peak beam intensities, and therefore improve space charge limits. The method can be extended to project X to enable high duty cycle extraction within space charge limits. A further extension should make possible an accumulator/buncher scenario that can provide 8 GeV short bunches for a neutrino factory and/or muon collider scenario.