The $I_{C}$ Irreversible Strain of Some ITER High $J_{C}$${\rm Nb}_{3}{\rm Sn}$ Wires

Abstract

ITER highNb 3 Sn wires are designed to compensate for the performance degradation due to transverse electromagnetic force in cable-in-conduit-conductor. characterization of these wires, especially as a function of axial strain, is very important. We performed irreversibility strain measurements and geometry examinations on two types of ITER high Nb 3 Sn wires.is measured in a 18 T magnetic field by a straight pull device developed at the NHMFL. Consistent difference in between the two types of strands is observed. We found that the is 0.3% for the type of strands with higher and 0.4% for that with lower . This can be correlated to the difference in their geometry.

Influence of the heat-treatment conditions, microchemistry, and microstructure on the irreversible strain limit of a selection of Ti-doped internal-tin Nb3Sn ITER wires

“…Nonetheless, the results we obtained on the alternatedesign wires are worth presenting within the scope of this work because they confirm the behavior of the 0.82 mm diameter wires (baseline design). Additional strain studies of the same Luvata and OST wires can be found elsewhere [37,42].…”

Insights on grain boundary effects on crack formation and propagation in Nb3Sn coatings at low temperature and high strain rates: a molecular dynamics simulation study

“…For Nb 3 Sn strand with different cross sectional structure (produced by different methods), the experimental test of fiber cracking under uniaxial cyclic loading carried out by Sheth et al [17] demonstrated that once strain reached 1% after 10 000 loading cycles, significant filament cracking was noticed in the bronze process strand, while in a Nb 3 Sn internal tin strand measured throughout the test for up to 1000 cycles of loading, significant filament cracking began to appear at the strain of 0.7%. A similar experiment on the irreversible strain limit of Nb 3 Sn strand (manufactured by luvata Waterbury company (Luvata) and Oxford instrument superconducting technology (OST)) conducted by Lu et al [18] also revealed a microstructure-dependent fracture behavior of Nb 3 Sn filament. With the aid of a direct drawing device, the experiment demonstrates that the irreversible strain of Luvata filament is larger than that of OST filament.…”