V3Ga 超伝導線材における高 Ga 濃度 Cu-Ga 化合物粉末を経由した新製法

Abstract

A superconducting magnet system is also one of the important components in an advanced magnetic confinement fusion reactor. Then it is required to have a higher magnetic field property to confine and maintain the steady-state burning deuterium (D)-tritium (T) fusion plasma in the large interspace during the long term operation. Burning plasma is sure to generate 14 MeV fusion neutrons during deuterium-tritium reaction, and fusion neutrons will be streamed and penetrated to superconducting magnet through large ports with damping neutron energy. Therefore, it is necessary to consider carefully not only superconducting property but also neutron irradiation property in superconducting materials for use in a future fusion reactor, and a “low activation and high field superconducting magnet” will be required to realize the fusion power plant beyond International Thermonuclear Experimental Reactor (ITER). V-based superconducting material has a much shorter decay time of induced radioactivity compared with the Nb-based materials. We thought that the V3Ga compound was one of the most promising materials for the “low activation and higher field superconductors” for an advanced fusion reactor. However, the present critical current density (Jc) property of V3Ga compound wire is insufficient for apply to fusion magnet applications. We investigated a new route PIT process using a high Ga content Cu-Ga compound in order to improve the superconducting property of the V3Ga compound wire.