Superconducting Properties and Microstructure of V3Ga Multifilamentary Wires Through a PIT Process Using High Ga Content Compounds.

We have reconsidered V₃Ga compound wire for future fusion reactor application. 14 MeV fast neutrons will be formed during the Deuterium-Tritium fusion reaction, consequently future fusion reactors will be constructed using low activation materials wherever possible. V₃Ga compound has a short radioactive decay time and it will be one of the candidate superconductors with both low activation and high field proper- ties so called "Low activation superconducting materials". The present critical current density, J_c, is insufficient for large fusion magnet. We investigated a new PIT process, using high Ga content compound, in order to improve superconducting properties. The upper critical field, H_c2, of the samples using high Ga content Cu-Ga compounds, was increased with increasing Ga content, and measured 22.5 T when was used 50 at % Ga compound powder. Moreover, the effect of Mg addition into the powder filament was also investigated. The small amount of Mg addition within 1 at %, was improved H_c2 to about 23.0 T. The Ga content dependence and the Mg addition effect on the superconducting properties in the new PIT process are reported in this paper. [ABSTRACT FROM AUTHOR]