Charge State Boosters for Radioactive Ion Acceleration

For the post acceleration of radioactive ions produced at ISOL facilities the increase of the charge state is essential to fulfill the A/q requirements of the accelerators. Many of those existing or proposed facilities are relying on the performance of charge state boosters of EBIS or ECRIS type. Although, in principle both types of sources can be used in pulsed or continuous mode operation an EBIS is better suited for pulsed beams whereas an ECRIS is most efficient in a continuous mode. The first charge state booster of the EBIS type had been installed at CERN/ ISOLDE and is working in a routine way since several years. It has been constantly optimized and reaches efficiencies in the order of 10% for a single charge state. More recently ECRIS type devices with similar efficiencies for noble gas ions are being set up and put into on line operation at KEK and TRIUMF. The paper will discuss the present state of the art with respect to existing data of both sources and potential future developments.