Facilities for the Intensity Frontier
The Steering Group considered a variety of accelerator facilities and programs using the following criteria:
- Support for physics research goals,
- effective use of accelerator assets freed up at the end of Tevatron operations,
- Alignment with the ILC R&D program,
- Potential for achievement over the next decade.
Twelve facilities received consideration using some or all of these criteria. Appendix G sorts those facilities not described in this chapter based on relevance to proton- or electron-based programs. This chapter describes the facilities that would support neutrino science and precision physics at the intensity frontier. The facilities include an intense proton source and its injection to the existing rings at Fermilab for a variety of programs.
There are two approaches to making an intense proton source at Fermilab. The first and more powerful approach would replace the present injection complex with Project X, an ILC-like linac capable of accelerating intense beams of either protons or electrons. Project X would use the linac, coupled to the Recycler and Main Injector, to produce much higher proton intensities in the range between 8 GeV and 120 GeV than the present complex. SuperNuMI, the second approach, would reconfigure the existing accelerator complex. Project X would be much more capable than SNuMI, which would leave the 35-year-old proton injection complex in place. SNuMI would provide less flexibility, involve more technical risk and have no alignment with the ILC—but it would also be less expensive and faster to implement than Project X. The Steering Group plan assumes a choice between SNuMI and Project X depending on the scope and longevity of the neutrino program and precision physics program, the desire to develop ILC technology on a real machine and the time available before construction of the ILC.
The table below represents the intensities of the present and future Fermilab accelerator complex using either SNuMI or Project X. The first three columns represent current performance and improvements now underway. The last two columns list SNuMI and Project X parameters. All columns are based on injecting beam from the existing 8 GeV Booster, except for Project X, which eliminates the need for the Booster. While the table does not list any beam power availability at 8 GeV in SNuMI, protons could be made available at this energy at the expense of availability at 120 GeV.
Possible evolution of proton availability at Fermilab
* NOνA column includes a potential upgrade of the Booster repetition rate to support simultaneous delivery of ~2×1020 protons per year at 8 GeV. NOνA itself requires Booster operations at 9 Hz.