The aim of the beta-beams is to produce pure electron neutrino and anti-neutrino highly energetic beams,coming from β-decay of the 18Ne10+ and 6He2+, both at γ = 100, directed towards experimental halls situated in the Fréjus tunnel. The high intensity ion beams are stored in a ring, until the ions decay. Consequently, all the injected particles will be lost anywhere around the ring generating a high level of irradiation. In order to keep a constant neutrino flux, the losses due to the decay of the radioactive ions are compensated with regular injections.
The new ion beam is then merged with the stored beam with a specific RF program. We have to consider two sources of losses:
– The β-decay products: their magnetic rigidity being different from the reference one, they are bent differently and lost.
– The losses during the injection merging process.
The first one needs a particular ring design in order to insert appropriate beam stoppers at the right place. The second one needs a specific collimation system which allows beam longitudinal halo cleaning between two successive injections. |
