The Main Dipole Magnets Design and Test of HIMM Project

In the project of Heavy Ion Medical Machine, there are eight dipole magnets in the synchrotron and ten dipole magnets in the high-energy beam line used for beam bending. Both types of dipole magnets have the same bending radius and bending angle, but the gaps are different. The maximum magnetic field of synchrotron dipole is 1.66 T, and the high beam line dipole is 1.6 T. The magnetic field calculation and the structure design are presented in this paper; the trim slot in the pole and the removable pole ends are used in order to reach the required field homogeneity. The magnetic field measurement results, which include field homogeneity and reproducibility, are also shown in details. The test results show that the dipole magnet design could satisfy the major specified physical requirements.