The UK at present has no nuclear physics facilities of its own, and very little investment in facilities overseas. “SIRIUS would open up many opportunities in a number of areas, most notably in materials science and nuclear astrophysics, ” says Bill Gelletly, the Surrey University physicist who is SIRIUS project scientist. SIRIUS may also have bio-medical applications, such as the production of long-lived species that could be injected into the body as tracers.

SIRIUS would produce radioactive nuclei by focusing a 100 µA beam of 800 MeV protons from the synchrotron at ISIS onto a heavy metal target. Radioactive nuclei produced in these collisions would then be separated and “re-accelerated” to higher energies. The SIRIUS plans allow for several low-energy beams (below 1 MeV per nucleon) and a high-energy beam. A superconducting linear accelerator would be used to re-accelerate nuclei to 10 MeV per nucleon.

SIRIUS project manager Hywel Price says that the Engineering and Physical Sciences Research Council and other funding bodies will have to look at SIRIUS in a European context. “I am optimistic that there will be a European radioactive beam facility, but whether it’s in the UK remains to be seen, ” he says. Since France, Germany and Italy may prefer to upgrade their existing facilities, the construction of SIRIUS would depend on the merits of using ISIS over other beam technologies. “The UK is very short of major facilities, ” says Gelletly. “My belief is that SIRIUS represents a first-class opportunity for the UK to create a world-class facility. We should grab it.”