Development of a Cyclotron Magnet
We developed a cyclotron magnet at the Institute of Modern Physics, Chinese Academy of Sciences (IMP, CAS); the whole system include one main magnet, one solenoid, and two quadrupoles, and is used to accelerate the H- beam. This paper describes the magnetic field design of one cyclotron, and several shimming methods are used to meet the isochronous magnetic field of the H- beam, including the pole face shimming method and side shimming method. The final optimization results show that the error between simulation and theory value is small. For the purpose of comparison, a detail magnetic field measurement on the cyclotron are carried out, the results show that the isochronous deviations between the measurements and theory values are less than 5 G at most radii, which satisfy the design requirement.