Design Calculation of a Improved ECR Ion Source

The design of a ECR ion source in a working mode with a ω_ecr resonance surfaces and a 2ω_rf enclosed surface is presented.The 0.8T axial mirror field and 0.8T radial hexapole field are introduced with detailed discussions.The computational results show that the axial length of the ω_ecr resonance surface in the improved ECR ion source is extended significantly compared with the original CAPRICE one and a closed 2ω_rf equigauss surface is also formed.The new topology of the magnetic field in the improved ECR ion source will largely raise the intensity of high charged ion on the basis of the analysis of ionization mechanism.