Magnetic Field Measurements of RCS Dipole for CSNS

The China Spallation Neutron Source (CSNS) is an accelerator-based multidisciplinary user facility. The CSNS facility consists of an 80 MeV H- linear accelerator (1inac), a 1.6 GeV rapid cycling synchrotron (RCS), beam transport lines, a target station, and three sets of instruments with auxiliary equipments. The RCS consists of 24 dipole magnets, 48 quadrupole magnets, 16 sextupole magnets and some corrector magnets. The magnets of the RCS are excited with a repetition frequency of 25 Hz AC bias DC. The magnetic field measurements of the dipole prototype under DC and 25 Hz AC bias DC were carried out at the Institute of High Energy Physics (IHEP). The integral field distribution, harmonic components, transfer function were measured. The measurement results are presented in this paper.