Thermomechanical Behavior of the HL-LHC 11 Tesla Nb3Sn Magnet Coil Constituents during Reaction Heat Treatment

TL;DR

This study investigates the thermomechanical properties of HL-LHC 11 Tesla Nb3Sn magnet coil constituents during reaction heat treatment, providing data crucial for predicting coil geometry and stress distribution post-heat treatment.

Contribution

It presents in situ measurements of Young's and shear moduli of coil and tooling materials during heat cycles, enhancing understanding of their thermal and mechanical behavior.

Findings

Measured Young's and shear moduli during heat cycles

Compared thermal expansion of coil components and Nb3Sn wire

Provided data for predicting coil stress and geometry

Abstract

The knowledge of the temperature induced changes of the superconductor volume, and of the thermo-mechanical behaviour of the different coil and tooling materials is required for predicting the coil geometry and the stress distribution in the coil after the Nb3Sn reaction heat treatment. In the present study we have measured the Young's and shear moduli of the HL-LHC 11 T Nb3Sn dipole magnet coil and reaction tool constituents during in situ heat cycles with the dynamic resonance method. The thermal expansion behaviours of the coil components and of a free standing Nb3Sn wire were compared based on dilation experiments.