Task 1: Innovative Charge Breeding Techniques –ICBT (CERN)
Contributing institutes: CERN, GANIL, UNIWARSAW
During the last decade the Electron-Beam Ion-Source (EBIS) technology has established itself as a key method for preparation of radioactive beams for further post-acceleration, and Europe has been the world-leader in the field. Now several oversea laboratories are either commissioning (ReA at NSCL-MSU and CARIBU at ANL, both US), designing (ARIEL at TRIUMF, Canada) or considering using (iThemba, South Africa and IBS-RISP, Korea) EBIS devices as charge breeders. Two of the tasks described below would reinforce our position and increase the EBIS-based charge-breeder knowledge. The future challenges for these breeders lie in the higher beam intensities delivered by the primary target, the request for curbed breeding times and the demand for fully stripped heavy ions (or few-electron systems) to be injected into consecutive storage rings. In addition, the experiments would profit from a CW extracted beam structure. This work package will address the important issues related to the achievement of these goals and to validate the feasibility of an EBIS/T type charge breeder for EURISOL. It should be based on recent developments related to the most crucial items, i.e. the production of a very high current, high energy and compression electron beam needed for such a charge breeder and the CW-preparation Paul trap. The first tests of an electron gun partially fulfilling these specifications will take place during 2014. The path to the successful production of CW EBIS beams has been paved within the EMILIE-NUPNET project during which an EBIS debuncher prototype was built.
Furthermore, charge breeders of ECR ion-source type are of interest for several facilities within Europe and elsewhere. Its high breeding throughput and relative simplicity are especially appealing. Experiments have indicated that the injection conditions into the plasma are very critical for the overall efficiency. Task 3 will optimise the capture and ionisation efficiency inside the ECR cavity through study of the impact of the injection electrode configuration, of the ion scattering on the support gas, and of the injection beam energy.