Dimensional Changes of Nb₃Sn Conductors and Conduit Alloys During Reaction Heat Treatment

The performance ofNb₃Sncomposite superconducting wire is highly dependent on its strain state, which is difficult to predict or measure accurately. There is limited data in the literature onNb₃Snor conduit alloys for the thermal expansion/contraction that occurs during reaction heat treatments. Thermal expansion measurements of two contemporaryNb₃Snwires and two conduit alloys—316LN and JK2LB—are taken individually during reaction heat treatments in a wide temperature range (4–1200 K) dilatometer system at the NHMFL. The measurements observed here are compared with the existing data and predicted models. This work significantly increases the available data forNb₃Snsuperconductors and conduit alloys that can be used in magnet design and predictive modeling.