Charge Breeding of Radioactive Ions in an Electron Cyclotron Resonance Ion Source(ECRIS) at ISOLDE

The development of an efficient charge breeding scheme for the next generation of RIB facilities will have a strong impact on the post-accelerator for several Radioactive Ion Beam (RIB) projects at European large scale facilities. At ISOLDE/CERN there will be the unique possibility to carry out experiments with the two possible charge breeding set-ups with a large variety of radioactive isotopes using identical injection conditions. One charge breeding set-up is the Penning trap/EBIS combination which feeds the REX-ISOLDE linear accelerator and which is in commissioning now. The second charge breeder is a new ECRIS PHOENIX developed at the ISN ion source laboratory at Grenoble. This ECRIS is now under investigation with a 14 GHz amplifier to characterize its performance. The experiments are accompanied by theoretical studies in computer simulations in order to optimize the capture of the ions in the ECRIS plasma. A second identical PHOENIX ECRIS which is under investigation at the Daresbury Laboratory is available for experiments with radioactive ions at ISOLDE in order to compare the breeding efficiency with the Penning trap/EBIS breeder with the same isotopes. The goal of the breeding experiments proposed are the investigation of the injection of ions into the ECRIS plasma and the loss mechanism, the maximum breeding efficiency and the breeding times. A comparison with REX-EBIS results will allow a more objective evaluation of both schemes. Especially the breeding efficiency for very weak currents will be of interest. A total of 15 shifts of beam time with an UC$_{2}$ target combined to various ion sources are requested to study charge breeding of radioactive isotopes like fission fragments. Later the ECRIS test stand will be available for experiments in astrophysics and deep implantation for solid state physics.