PIP-II

PIP-II
U.S. Geological Survey · Public domain · source
Name	PIP-II
Location	Fermi National Accelerator Laboratory
Type	Proton linear accelerator
Status	Under construction
Start	2019
Cost	US$1.1 billion (estimated)

PIP-II PIP-II is a multi-megawatt proton linac project led by Fermi National Accelerator Laboratory to upgrade the neutrino program at Fermilab and enable high-intensity beams for experiments such as DUNE and NOvA. The project integrates superconducting radio-frequency technology developed in collaboration with institutions including Brookhaven National Laboratory, Argonne National Laboratory, SLAC National Accelerator Laboratory, and international partners like CERN and TRIUMF. PIP-II is designed to inject high-power beams into the existing Main Injector (Fermilab) complex to serve long-baseline experiments and short-baseline programs anchored at facilities such as NuMI and Short-Baseline Neutrino (SBN) Program.

Overview

PIP-II is an accelerator upgrade initiative at Fermi National Accelerator Laboratory that aims to provide a continuous-wave-capable, superconducting linac to deliver up to 1.2 MW of 120 GeV proton beam power for long-baseline neutrino experiments like DUNE while supporting other programs including Muon g-2 and Mu2e. The collaboration spans US national laboratories and international organizations such as CERN, CEA Saclay, RAL, and INFN, reflecting a global effort to advance superconducting radio-frequency systems used in projects like ILC and ESS. The upgrade is intended to modernize injector chains preceding the Main Injector (Fermilab), replacing legacy systems similar to upgrades undertaken at KEK and J-PARC.

Design and Components

The PIP-II linac design employs continuous-wave-capable superconducting cavities patterned after developments at DESY and Jefferson Lab with four families of cavities (HB650, LB650, SSR1, SSR2 analogs) manufactured and tested by partners including Fermilab, LANL, and Brookhaven National Laboratory. The front end uses an ion source and a low-energy beam transport inspired by designs from CERN and TRIUMF, followed by a room-temperature radio-frequency quadrupole similar to units used at ISAC and SNS. The cryomodules, cryogenics, and high-power RF systems leverage expertise from SLAC National Accelerator Laboratory and CEA Saclay, integrating low-level RF control strategies demonstrated at FLASH and XFEL. Beam diagnostics, vacuum systems, and beamline elements echo instrumentation developed for VECC projects and upgrades at RAL.

Construction and Installation

Construction of PIP-II involves staged fabrication at facilities such as Fermilab, Brookhaven National Laboratory, Argonne National Laboratory, and partner industrial vendors in the United States and Europe, with component testing at cryomodule test stands modeled on facilities at DESY and Jefferson Lab. Installation phases coordinate with maintenance periods for the Recycler (Fermilab) and Main Injector (Fermilab), and civil works on the Fermi National Accelerator Laboratory site follow environmental reviews similar to processes used for DUNE and LBNF infrastructure. International in-kind contributions from CERN, INFN, and TRIUMF supply key RF, cryogenic, and cavity components, while quality assurance mirrors procedures at ITER and LIGO for complex systems integration.

Performance and Beam Parameters

PIP-II is specified to accelerate H- ions to 800 MeV with beam currents and duty cycles enabling up to 1.2 MW at 120 GeV after injection and stacking in the Main Injector (Fermilab), supporting beam formats required by DUNE and enhancing capabilities like high-intensity spills used by SBN Program detectors. The superconducting cavities operate at frequencies and gradients benchmarked against results from ILC R&D and European XFEL campaigns, with cryogenic loads comparable to those calculated for TESLA-style modules. Expected beam emittance, loss budgets, and transmission efficiencies adopt standards from SNS operations and beam dynamics studies performed at LANSCE.

Scientific and Facility Impact

PIP-II directly enables the long-baseline program centered on DUNE by supplying higher proton intensities to the NuMI/beamline complex and fosters experiments in neutrino oscillation, sterile neutrino searches, and precision muon physics linked to projects like Mu2e and Muon g-2. Facility-wide, the upgrade increases capabilities for users drawn from institutions such as University of Chicago, MIT, Caltech, University of Michigan, and international groups at CERN and INFN. PIP-II’s superconducting linac technology also contributes experience applicable to future proposals like ILC and informs accelerator science training programs at universities affiliated with Fermilab and partner laboratories including Argonne National Laboratory.

Project Timeline and Funding

The PIP-II project follows a staged schedule with key milestones aligned to DUNE beam commissioning, starting with front-end commissioning and cryomodule deliveries in the early 2020s and aiming for integrated operation in the mid-2020s to early 2030s. Funding sources combine US Department of Energy investments through Office of Science (DOE) program allocations and international in-kind contributions from CERN, INFN, CEA Saclay, and TRIUMF, with project governance modeled on large-scale collaborations like LHC upgrades and ITER. Cost control and schedule oversight apply practices used in projects such as SNS and XFEL.

Safety and Environmental Considerations

Safety planning for PIP-II incorporates radiological protection protocols used at Fermilab and benchmarked against standards at CERN and DESY, including air activation control, shielding design informed by ISOLDE experience, and access controls like those at LHC experiments. Environmental reviews addressed groundwater, land use, and ecological impacts consistent with assessments performed for LBNF infrastructure, and emergency planning aligns with procedures practiced by Fermilab emergency management and partner institutions such as Brookhaven National Laboratory.

Category:Particle accelerators