Superconducting Magnet Design for the Hyperfine Structure Measurement of Muonium at the J-PARC

A superconducting magnet system for a new muonium hyperfine structure, MuHFS, measurement at J-PARC is being developed. This experiment requires a magnetic field strength of 1.7 T with high homogeneity below 1 ppm. The overall mechanical design including helium and vacuum vessels was almost completed. In order to evaluate the influence of coil vibration on the error field, the modal analysis was performed. The conceptual design of superconducting shim coils was carried out. The zonal and radial shim coils were designed by using the conventional spherical harmonics method and the singular value decomposition method, respectively.