Charge breeder electron cyclotron resonance ion sources (CB-ECRIS) are used as 1+ →n+ charge multiplication devices of post-accelerated radioactive ion beams. The charge breeding process involves thermalization of the injected 1+ ions with the plasma ions in ionion collisions, subsequent ionization by electron impact and extraction of the n+ ions. Charge breeding experiments of 85 Rb and 133 Cs ion beams with the 14.5 GHz PHOENIX CB-ECRIS operating with oxygen gas demonstrate the plasma diagnostics capabilities of the 1+ injection method. Two populations can be distinguished in the m/q-spectrum of the extracted ion beams, the low (1+ and 2+) charge states representing the uncaptured fraction of the incident 1+ ion beam and the high charge states that have been captured in ion-ion collisions and subsequently charge bred through electron impact ionization. Identification of the uncaptured fraction of the 1+ ions allows estimating the lower limit of ion-ion collision frequency of various charge states in the ECRIS plasma. The collision frequencies of highly charged ions (∼10 7 Hz) are shown to exceed their gyrofrequencies (∼10 6 Hz) at least by an order of magnitude, which implies that the dynamics of high charge state ions are dictated by magnetically confined electrons and ambipolar diffusion and only low charge state ions can be considered magnetized. Furthermore, it is concluded that the plasma density of the ECRIS charge breeder is most likely on the order of 10 11 cm −3 i.e. well below the critical density for 14.5 GHz microwaves.

The EUROnu project has studied three possible options for future, high intensity neutrino oscillation facilities in Europe. The first is a Super Beam, in which the neutrinos come from the decay of pions created by bombarding targets with a 4 MW proton beam from the CERN High Power Superconducting Proton Linac. The far detector for this facility is the 500 kt MEMPHYS water Cherenkov, located in the Fr\'ejus tunnel. The second facility is the Neutrino Factory, in which the neutrinos come from the decay of {\mu}+ and {\mu}- beams in a storage ring. The far detector in this case is a 100 kt Magnetised Iron Neutrino Detector at a baseline of 2000 km. The third option is a Beta Beam, in which the neutrinos come from the decay of beta emitting isotopes, in particular 6He and 18Ne, also stored in a ring. The far detector is also the MEMPHYS detector in the Fr\'ejus tunnel. EUROnu has undertaken conceptual designs of these facilities and studied the performance of the detectors. Based on this, it has determined the physics reach of each facility, in particular for the measurement of CP violation in the lepton sector, and estimated the cost of construction. These have demonstrated that the best facility to build is the Neutrino Factory. However, if a powerful proton driver is constructed for another purpose or if the MEMPHYS detector is built for astroparticle physics, the Super Beam also becomes very attractive

Due to the production methods of exotic nuclei, an efficient acceleration of radioactive ion beams needs charge breeding of weakly charged ions. The upgrade of existing isotope separator on-line facilities ͑TRIUMF-isotope separation and acceleration, CERN-isotope separation on-line detector, etc.͒ or the development of projects for the acceleration of radioactive ion beams ͑GANIL-SPIRAL2, MAFF, EURISOL, etc.͒ requires charge breeders with high efficiency, fast charge breeding time, low background levels, and high intensity acceptance either in continuous or in pulsed mode. The optimization of these parameters is a challenge for the electron cyclotron resonance ͑ECR͒ community and is useful to get a better understanding of plasma physics in ECR ion sources ͑ECRISs͒. The ECR charge breeding technique has been developed for more than ten years at LPSC ͑former ISN͒ Grenoble, typical 1 + → n+ efficiencies are in the 3%-10% range depending on the nature of the incoming beam ͑metallic, alkaline, and gaseous͒ and remain constant for high intensity injection. Different laboratories have developed programs to study ECR charge breeding, and the progress of these studies will be presented. ECRISs have main advantages to be efficient charge breeders and a few limitations which will be discussed.