Magnetization study of ITER-type internal-Sn Nb3Sn superconducting wire

Chaowu Zhang (1) , Lian Zhou (2) , André Sulpice (3) , Jean-Louis Soubeyroux (3) , Christophe Verwaerde (4) , Ky Hoang Gia (4) , P.X. Zhang (2) , Yafeng Lu (2) , Xiande Tang (2)

1 Shaanxi University of Science and Technology
2 NIN - Northwest Institute for Nonferrous Metal Research
3 NEEL - MagSup - Magnétisme et Supraconductivité
4 Alstom Magnets and Superconductors

Through magnetization measurement with a SQUID magnetometer the heat treatment optimization of an international thermonuclear experimental reactor (ITER)-type internal-Sn Nb3Sn superconducting wire has been investigated. Their reversibility temperature T* (H), which is mainly dependent on A15 phase composition, was obtained by a warming and cooling cycle at a fixed field. The hysteresis width triangle M(H) which reflects the flux pinning situation of the A15 phase is determined by the sweeping of magnetic field at a constant temperature. The results obtained from differently heat-treated sampless how that the combination of T* (H) with triangle M(H) measurement is very effective for optimizing the heat reaction process. The heat treatment condition of the ITER-type wire is optimized at 675 degrees C/128 h, which results in a composition closer to stoichiometric Nb3Sn and a state with best flux pinning.

Mots clés: Nb3Sn superconducting wire; internal-Sn process; irreversibility temperature; hysteresis width

Domaines: Matériaux

Chaowu Zhang, Lian Zhou, André Sulpice, Jean-Louis Soubeyroux, Christophe Verwaerde, et al.. Magnetization study of ITER-type internal-Sn Nb3Sn superconducting wire. Chinese Physics -Beijing-, 2007, 16 (6), pp.1764-1769. ⟨10.1088/1009-1963/16/6/048⟩. ⟨hal-00715288⟩