Development of ECR ion source for production of the intense beam of the highly charged heavy ions

Electron cyclotron resonance (ECR) ion sources for production of intense beam of highly charged heavy ions are widely used as an external in source for heavy ion accelerator. Especially, it is one of the key devices of the heavy ion accelerator facilities for radio isotope beam production. At RIKEN, several ECR ion sources have been constructed and used for production of the intense beam in the past 30 years. Moreover, we studied the effects of the key parameters (magnetic field distribution, RF power, gas pressure etc) of the ion source on the beam intensity of highly charged heavy ions and ECR plasma. In this contribution, we present the effect of the key parameters, especially magnetic field distribution, on the beam intensity of the heavy ions and the performance of the ECR ion sources at RIKEN. (author)