Baseline ion production dedicated to beta-beams

Beta-beams, a concept introduced in 1991, require a large facility that produces and accelerates to high energy electron neutrino and antineutrino beams for oscillation experiments. They are produced by b decay of radioactive ion beams in a dedicated ring directed towards underground detectors. This article addresses the production of the 6He and 18Ne baseline ions. Part of the results were obtained within EURISOL-DS, a design study for the next generation OnLine Isotope Separation facility for nuclear physics in Europe. 200 kW, 2 GeV protons on a solid neutron spallation source surrounded by a thick beryllium oxide target produce the required 6He rates, while 18Ne production falls short by more than an order of magnitude. A first alternative might fulfil the objectives with a 30 MeV 3He primary beam onto large solid oxide target disks at several MW. A second 18Ne production alternative is based on a 700 kW proton beam at medium energy (70-160 MeV) and a target made of a circulating molten salt loop.