Proton Improvement Plan-III (PIP-III)

General

PIP-III is currently a generic term used to capture activity related to proposed activities to increase the high energy (60-120 GeV) proton power from the Fermilab Main Injector beyond the 1.2 MW goal of PIP-II. The goal of this effort is to set a performance baseline for long term planning, as well as to identify open questions which will require R&D resources to answer in the near term.

Reference Specifications

We are working toward a target power of at least 2.5MW at 120 GeV and at least 2.0MW at 60 GeV.  It's clear that going beyond 1.2 MW will require replacing the existing Booster, which by then will be more than half a century old.  Two options being considered are:
  • Replacing the Booster with a 20 Hz rapid cycling synchrotron (RCS), and eliminating the Recycler as a pre-loader.
or
  • Replacing the Booster with an 8 GeV pulsed linac and continuing to inject into Recycler in order to produce short pulses for other 8 GeV users.
With current technology, the RCS option would be lower cost, we have tentatively chosen that as the reference appraoch; however, the linac offers more versatility, and there is a great deal of work going on to reduce the cost, so we will continue to investigate that as a backup.

Straw man parameters for PIP-III can be found in this spreadsheet, produced by Valeri Lebedev, Paul Derwent, and Steve Holmes.  A summary of the beam requirements can be found in this document.

Main Areas of Research

The key areas of research should focus on the following:
  • Determining whether the new RCS will be injected directly from the PIP-II 800 MeV linac, or whether an additional linac will be added to increase the injection energy to 2 GeV.  This decision depends largely on whether a viable technique can be found to mitigate space charge tuneshift at injection into the RCS.  Promising approaches include the following, which will both be studied extensively  in the IOTA ring, at the FAST facility:
    • integrable non-linear optics
    • electron lenses
  • Determining the optimum circumference for the RCS.  Estimates so far have assumed that it will have the same circumference as the existing Booster (1/7th of the Main Injector), but a larger circumference would reduce the loading time.
  • Determining the optimum injection energy for the Main Injector.  Current estimates assume it remains at 8 GeV, but raising it could reduce cycle times and possibly mitigate space charge issues.
  • Determining the specifications for a new RF system in the Main Injector.
  • Loading, space charge, and electron cloud issues in the Main Injector.
  • Continuing consideration of the linac option, including cost and indrialization, as well as injection issues

Selected Presentations

Research Plan

(under construction)