| 摘要 |
PROBLEM TO BE SOLVED: To improve the opening performance and magnetic field uniformity of an open type magnet using a pole piece. SOLUTION: Static magnetic field generating sources 13a, 13b are disposed in the vertical direction with a uniform magnetic field area 12 interposed between them, and the static magnetic field generating sources 13a, 13b are supported by upper and lower magnetic plates 14a, 14b provided with pole pieces 18a, 18b and superconductive coils 26a, 26b and supported by magnetic posts 16. The pole pieces 18a, 18b have uniformity control materials 22a, 22b disposed in the central area and annular projecting parts 20a, 20b disposed in the outer peripheral part, and the superconductive coils 26a, 26b are stored in cooling containers 28a, 28b disposed in contact with the outer peripheries of the annular projecting parts 20a, 20b. Layer products 24a, 24b of directional silicon steel plates are disposed on the opposite surfaces 32 of the annular projecting parts 20a, 20b so that the surface of the steel plate and the opposite surface 32 are substantially parallel. The magnetic flux generated in the superconductive coils 26a, 26b is turned in the direction of an arrow 33 at the parts of the layer products 24a, 24b, thereby increasing the magnetic field intensity of the outer peripheral part (A part) of the uniform magnetic field area 12. |
