Proton Improvement Plan

Proton Improvement Plan

The Proton Improvement Plan is a staged accelerator upgrade program at Fermi National Accelerator Laboratory aimed at increasing proton beam power and reliability for neutrino experiments and fixed-target physics. Initiated to support projects such as NOvA, MINERvA, MicroBooNE, and the later Deep Underground Neutrino Experiment, it involved coordinated work on the Booster (Fermilab), Recycler (accelerator), Main Injector (Fermilab), and associated beamlines. The program connected to national priorities set by the U.S. Department of Energy and coordinated with research groups at institutions including University of Chicago, Columbia University, Massachusetts Institute of Technology, and international partners such as CERN.

Background and Motivation

The initiative responded to operational constraints observed during runs for experiments like MINOS and planning efforts for NOvA and future long-baseline projects exemplified by LBNE planning. Drivers included limits in cycle time and intensity in the Booster (Fermilab), losses in the Main Injector (Fermilab), and the need to feed the Neutrinos at the Main Injector program. Stakeholders included the High Energy Physics Advisory Panel (HEPAP), the Fermilab Accelerator Division, and funding offices within the U.S. Department of Energy. Technical reviews referenced experience from upgrades at CERN Super Proton Synchrotron, lessons from Brookhaven National Laboratory, and accelerator science developments from groups at SLAC National Accelerator Laboratory and Argonne National Laboratory.

Design and Upgrades

Design choices targeted multiple subsystems: resonant frequency control, magnet power supplies, RF cavities, collimation, and beam instrumentation. Major elements were upgrades to the Booster (Fermilab) cycle through improved RF systems influenced by designs used at Paul Scherrer Institute and TRIUMF, enhanced magnet correctors akin to hardware at Brookhaven National Laboratory, and new collimation schemes drawing on practices from the Large Hadron Collider. The plan incorporated installation of new digital Low-Level RF systems similar to deployments at CERN and modern beam position monitors referenced by projects at European Organization for Nuclear Research facilities. Improvements to the Recycler (accelerator) allowed for slip-stacking techniques also used in studies at KEK and J-PARC to increase the intensity delivered to the Main Injector (Fermilab). Radiation shielding and loss mitigation followed protocols developed in collaboration with radiation safety teams from Lawrence Berkeley National Laboratory and accelerator experts from Imperial College London.

Construction and Implementation

Implementation occurred across multiple technical workstreams coordinated by the Fermilab Accelerator Division with contributions from university groups at University of Oxford, University of Manchester, Pennsylvania State University, and University of Michigan. Hardware procurement involved vendors experienced from upgrades for Spallation Neutron Source and industrial partners that had supplied systems for CERN Large Hadron Collider experiments such as ATLAS and CMS. Installation phases were scheduled around physics runs for NOvA and MINOS+, requiring close coordination with Neutrino beamline operations and detector collaborations like MINERvA and MicroBooNE. Commissioning drew on expertise from accelerator physicists who had worked on Recycler (accelerator) modifications and slip-stacking operations for intensity frontier programs. Safety oversight referenced standards from the U.S. Department of Energy Office of Science and integrated testing with diagnostics developed in collaboration with Fermilab Test Beam Facility teams.

Performance and Scientific Impact

After staged completion, the upgrades enabled increased beam power to the NuMI beamline, benefitting experiments such as NOvA, MINOS+, MINERvA, MicroBooNE, and preparatory work for the Deep Underground Neutrino Experiment. Higher intensity supported improved statistical reach for measurements of neutrino oscillation parameters pursued by collaborations including NOvA Collaboration and DUNE Collaboration planning teams. The program reduced beam losses and improved uptime, informing accelerator physics studies published by groups at Fermilab, SLAC National Accelerator Laboratory, Brookhaven National Laboratory, and university partners like University of Wisconsin–Madison and University of Texas at Austin. Technical outcomes influenced upgrade plans at international facilities, including concepts referenced in proposals for CERN SPS programs and intensity upgrades at J-PARC. The enhanced proton delivery enabled ancillary fixed-target programs in hadron structure research linked with collaborations involving Jefferson Lab and detector developments for experiments such as SeaQuest.

Funding, Collaboration, and Timeline

Funding originated from allocations by the U.S. Department of Energy Office of Science with programmatic oversight influenced by recommendations from High Energy Physics Advisory Panel (HEPAP) and coordination with national laboratory budgets at Fermi National Accelerator Laboratory and partners including Brookhaven National Laboratory and SLAC National Accelerator Laboratory. International in-kind contributions and university-led work packages augmented domestic funding, with participating institutions such as University of Chicago, Columbia University, Massachusetts Institute of Technology, University of Oxford, and Imperial College London providing personnel and R&D. The timeline unfolded in phases aligned with experimental needs for NOvA and future DUNE plans, with major milestones achieved in the 2010s and lessons carried into subsequent accelerator upgrade projects. Category:Accelerator projects