The electron cyclotron resonance (1+n+) systems and the ISOL radioactive beam facilities (invited)

Short life radioactive beams presently need charge breeders either for continuous or pulsed postaccelerators. Until recently these charge breeders were mainly based on stripper foils and or electron beam ion source projects associated with ion trap bunching devices. In 1995 however, we demonstrated the feasibility of radioactive electron cyclotron resonance ion source (ECRIS) charge breeders with rather good efficiencies working in continuous regime and well adapted for continuous postaccelerators. In 1998, we demonstrated also the feasibility of pulsed ECR ion traps (ECRITs) which are well adapted for pulsed postaccelerators with short life radioactive ion bunches. In this article, we explain the basic principles of these devices shortly named (1+n(+)) ECR systems and compare their characteristics with other systems. More precise results are given in companion articles at this meeting. (C) 2000 American Institute of Physics. [S0034-6748(00)64702-0].