| 摘要 |
A magnetic field generator (10) which suppresses a decrease in the magnetic field intensity and a deterioration in the magnetic field uniformity after transportation, and its manufacturing method. The magnetic field generator (10) comprises a pair of plate yokes (12a, 12b). Permanent magnets (14a, 14b) are disposed on the opposite faces of the pair of plate yokes (12a, 12b), and magnetic pole plates (16a, 16b) are fixed on the opposite faces of the permanent magnets (14a, 14b). The permanent magnets (14a, 14b) comprise permanent magnets (18). The magnetic pole plates (16a, 16b) comprise annular projections (24) and permanent magnets (28) for preventing a leakage flux provided on the outside faces of the annular projections (24). The permanent magnets (18, 28) comprise R-Fe-B magnets with a magnetization rate of 80% or more and 99.9% or less. During manufacture, the whole of the assembled magnetic field generator (10) is heated at 40ringC or more and 70ringC or less. |
