An 8 GeV Linac as the Booster Replacement in the Fermilab Power Upgrade: a Snowmass 2021 White Paper

Muon Collider Forum report

“…The initial part of that design is being constructed at Fermilab as PIP-II [154], an 0.8 GeV linac capable of 1.6 MW in CW operation. As discussed in Snowmass white papers, PIP-II can be extended to higher energies using a linac-based upgrade [155] or a linac plus RCS system [156]. These upgrades could be developed into proton drivers for a muon collider.…”

RF Accelerator Technology R&D: Report of AF7-rf Topical Group to Snowmass 2021

“…SRF cavities make up the vast majority of the PIP-II linac, which will provide high-intensity proton beam to drive the neutrino facility LBNF/DUNE [6]. One of the options for the multi-MW Fermilab Proton Intensity Upgrade is based on an SRF linac [7]. SRF systems accelerate beams of the LHC and will provide crabbing at the interaction regions to boost luminosity of the HL-LHC [8].…”

“…However, in the medium accelerating gradient range (from 15 to 25 MV/m), already developed recipes have an impact on the performance of prototype SRF cavities for PIP-II and CEPC [13]. Further developments will impact FCC-ee [12], multi-MW Fermilab Proton Intensity Upgrade [7], and possibly a muon collider. For machines that are proposed to operate at higher gradients, new recipes, e.g., 2-step baking, will push the cavity performance to 55-60 MV/m in standing wave structures and to ∼ 70 MV/m and beyond in traveling wave SRF structures [22].…”