A high intensity 6 He beam for the β-beam neutrino oscillation facility

This work presents the production and extraction of the short-lived radionuclide 6 He in yet unmatched yields from the ISOLDE facility at CERN. It is the first report of 6 He production using spallation neutrons via the 9 Be(n, α) 6 He reaction. These neutrons are produced from the 1.4 GeV proton beam of the Proton Synchrotron Booster (PSB) striking a tungsten converter, and are impinging on a porous BeO material. The central position of 6 He in future experiments is due to its role as a necessary radioactive nucleus to realize the β- beam at CERN, a next-generation facility to study neutrino oscillation parameters, and hence neutrino masses. In the β-beam scenario, an intense beam of radioactive 6 He nuclei will be produced, accelerated to multi-GeV energies and stored in a dedicated storage ring. The resulting virtually mono-directional anti-neutrino beam from the decay of the stored 6 He nuclei will be directed towards a remote underground neutrino detector. A similar beam of, e.g. , 18 Ne will provide neutrinos, an ideal concept to test CP violation in the neutrino sector. The results of the present experiment demonstrate for the first time that the necessary conditions for the realization of the proposed β- beam scheme with anti-neutrinos can be fulfilled.