| 摘要 |
PURPOSE:To enable detection of normal conduction transition without having effects of electromagnetic noises, by disposing an optical fiber, in which its inner optical propagation states varies dependently on temperatures, in a superconducting magnet and detecting the transition on the basis of temperature changes when the normal conduction transition occurs in a magnet. CONSTITUTION:An optical fiber 1, in which its internal optical propagation states are varied dependently on temperature, is disposed in a magnet by such a method that the fiber 1 together with superconductors 2 are wound. Variations of the optical propagation states in the optical fiber 1 are detected by making detective light incident to one end of the optical fiber 1 and taking out its light from the other end. When normal conduction transition occurs, the detection of this transition is thus possible because signal variations appear at once in the optical detector due to temperature changes in the magnet. Further, since an electrical filter for noise removal is also necessary for use, a response speed can be much enlarged. Thus, a superconducting magnet, which is operated with high reliability even under operational conditions where the detection of the normal conduction transition is hard, can be manufactured. |
