Title :
Development of variable field-direction superconducting magnet
Author :
Matsumoto, Shinji ; Kiyoshi, Tsukasa ; Ozaki, Osamu ; Fujihira, Jun-Ichi ; Koyanagi, Kei ; Wada, Hitoshi
Author_Institution :
Tsukuba Magnet Lab., Nat. Inst. for Mater. Sci., Ibaraki, Japan
fDate :
6/1/2003 12:00:00 AM
Abstract :
Magnetic field direction often has a great influence on material properties, such as critical current densities of tape-shaped superconductors. To determine the influence, an object is usually rotated in a fixed magnetic field. This method, however, is not always effective. We are developing a superconducting magnet that can change its field direction continuously in a two-dimensional plane. Two sets of split-pair coils are placed perpendicularly to each other, and the perpendicular magnetic fields generated by each split-pair coil are superimposed. By independently controlling the operating current of each split-pair coil, the direction of the superimposed magnetic field can be changed continuously. The coils are wound with Ni-Ti conductors. The variable field-direction magnet is designed to rotate a field of 1 T. The field homogeneity is estimated to be less than 1% in a 10-mm diameter sphere volume. This is a conduction-cooled superconducting magnet with 4K-GM refrigerators. Predictions derived by numerical calculations show that the electromagnetic forces among coils are quite large.
Keywords :
electromagnetic forces; nickel alloys; superconducting coils; superconducting magnets; titanium alloys; 1 T; 4 K; Gifford-McMahon refrigerator; Ni-Ti; Ni-Ti conductor; conduction cooling; electromagnetic force; split-pair coil; two-dimensional perpendicular magnetic fields; variable-field-direction superconducting magnet; Conductors; Critical current density; Magnetic fields; Magnetic variables control; Material properties; Refrigerators; Superconducting coils; Superconducting magnets; Superconductivity; Wounds;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2003.812774