Performance of H-/D- cyclotron using internal source

Over the past ten years, several models of H^-/D^- compact cyclotrons using an internal source have been constructed and put into routine operation. This paper reports the performance of some of these machines. A detailed description on individual cyclotrons is omitted in order to give space for discussion on the design guidelines and the criteria which warrant the high beam current capability. It has been found that the design of the ion source and the central region (beam centering, axial focusing strength, puller voltage and RF phase acceptance, etc.) together with the design of the vacuum system determine the initial beam current capability. Subsequently, the magnet phase profile (energy gain per turn), magnet optics quality and the vacuum characteristics dictate beam survival before extraction. Finally, the required beam quality after charge exchange in turn influences the design of the magnet structure. A thorough understanding on these coupled relationships between critical parameters is essential for the successful design of this type of cyclotron