1994 年 29 巻 12 号 p. 637-645
A 2.5T/100KVA AC superconducting magnet using a high-Jc NbTi superconducting wire having the designed Nb island-type artificial pins has been developed to demonstrate the advantages of using a high-Jc superconducting wire and the validity of the pin-design method based on the previous experimental results. The controlled pin parameters of the wire led to the achievement of the maximum Fp at 2.5T and the high critical current density, such as 4.7×109A/m2 at 2.5T as designed. The AC magnet wound by the wire was operated at 4.2K and 60Hz, reaching the electrical capacity of 104.8KVA (the current and voltage were 105.8 Arms and 991.2 Vrms, respectively) and the central magnetic field of 2.5T. The total AC losses in operating at the central magnetic field of 2T were extremely small, about 4.8W which was 0.007% of the electrical capacity, 69KVA. Moreover, the losses are drastically reduced compared with conventional AC magnets with a similar specifications because of its compactness and lowered inductance. It points out the usefulness of an AC magnet miniaturized by using a high-a Jc AC superconducting wire having the designed artificial pins.