A New Wire Fabrication Processing Using High Ga Content Cu-Ga Compound in V3Ga Compound Superconducting Wire

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 V 3 Ga 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 ( J c ) property of V 3 Ga 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 V 3 Ga compound wire.

Microstructure of V₃Ga Superconducting Wire Using Cu/V with High Ga Contents

“…thought that the high Ga content in the Cu-Ga compound material was an effective method to improve J C of the V 3 Ga compound wire, just like the high Sn content Nb 3 Sn wires. They tried to develop the new route for the fabrication of V 3 Ga compound wire with high Ga content Cu-Ga compound using the PIT processed precursors in order to improve the cold workability and volume fraction of the synthesized A15 phase, and investigated its microstructure and superconducting properties [3,4]. It was confirmed that the thicker V 3 Ga layer formed along the interface of Cu-Ga powder core and V matrix compared with previous diffusion processed samples for the multifilamentary wires.…”

“…It is also one of the important components in an advanced magnetic confinement fusion reactor [1]. In previous study, V 3 Ga compound wire was mainly investigated the "Diffusion process" between Cu-Ga solid solution matrix within 20 at% Ga composition and V filament [2]. It has been reported that the drastic critical current density (J C ) of Nb 3 Sn will be improved by increasing Sn content in the Cu-Sn matrix.…”

Microstructure of the New Route Wire Fabrication of V₃Ga Compound Superconducting Wire Using High Ga Content Cu-Ga/V Precursor Composite Material

“…It is also one of the important components in an advanced magnetic confinement fusion reactor [1]. In previous study, V 3 Ga compound wire was mainly investigated "Diffusion process" between Cu-Ga solid solution matrix within 20 at% Ga composition and V filament. The drastic critical current density (J C ) improvement by increasing of Sn content in the Cu-Sn matrix on Nb 3 Sn was reported.…”

“…thought that the high Ga content in the Cu-Ga compound material was an effective method in order to improve J C of the V 3 Ga compound wire, just like for the high Sn content processed Nb 3 Sn wires. They tried to develop the new route wire fabrication of V 3 Ga compound wire using high Ga content Cu-Ga compound through the PIT processed precursors in order to improve cold workability and volume fraction of synthesized A15 phase, and investigated its microstructure and superconducting properties [2,3]. It was confirmed that the thicker V 3 Ga layer formed along the interface of Cu-Ga powder core and V matrix compared with previous diffusion processed samples in the case of the multifilamentary wires.…”