Proton Accelerators for Science and Innovation

John Womersly, CEO of the Science and Technology Facilities Council (STFC), and Fermilab Director Pier Oddone signed a letter of intent outlining the goals of the collaboration over the next five years. Photo: Reidar Hahn

Last week we hosted the US-UK Workshop on Proton Accelerators for Science and Innovation. The workshop brought together scientists from the United States and the United Kingdom who are working on high-intensity proton accelerators across a variety of fronts. The meeting included not only the developers of high-intensity accelerators but also the experimental users and those involved in the applications of such accelerators beyond particle physics. At the end of the conference, John Womersly, CEO of the UK’s Science and Technology Facilities Council, and I signed a letter of intent specifying the joint goals and activities of our collaboration for the next five years. We plan to have another workshop in about a year to review progress and explore additional areas of collaboration.

Our collaboration with scientists from the United Kingdom in the area of high-intensity proton accelerators is already well established. We have a common interest in muon accelerators, both in connection with neutrino factories and muon colliders. Both of these future projects require multi-megawatt beams of protons to produce the secondary muons that are accelerated. We collaborate on the International Muon Ionization Cooling Experiment at the Rutherford Appleton Laboratory. MICE is the first muon cooling experiment and an essential step in the road to neutrino factories and muon colliders. We also collaborate on the International Scoping Study for neutrino factories.

In our current neutrino program we are very appreciative of this collaboration and U.K. expertise in the difficult mechanical design of high-power targets, in particular for the MINOS, NOvA and LBNE experiments. The design of these targets is quite challenging as the rapid deposition of energy creates shock waves that can destroy them.The Project X experimental program also depends on having appropriate megawatt-class targets relatively close to experimental set-ups.

One of the primary interests in applications outside of particle physics is the development of intense proton accelerators that could be used for the transmutation of waste or even the generation of electrical power in subcritical nuclear reactors. The accelerators necessary for such subcritical reactors could not have been built just a decade ago, but the advent of reliable superconducting linacs changed that. Several programs abroad are developing such accelerators coupled to reactors. While the United States has no explicit program on accelerator-driven subcritical systems, the technologies that we are developing for other applications, such as Project X, place us in a good position should the United States decide to develop such systems.

Overall, the workshop was very productive and the areas of potential collaboration seemed to multiply through the meeting. Each one of the five working groups is preparing a brief summary of the potential areas of collaboration as well as a specific and focused plan for the next year.