Brittle superconducting magnets: an equivilent strain model

Barzi, E. ; /Fermilab ; Danuso, M.

关键词: ACCELERATORS;    BUILDERS;    CABLES;    CERAMICS;    DESIGN;    MAGNETS;    SCALARS;    SENSITIVITY;    STRAINS;    SUPERCONDUCTING MAGNETS;    SUPERCONDUCTORS Accelerators;   

DOI  :  10.2172/1015378
RP-ID  :  FERMILAB-TM-2449-TD
PID  :  OSTI ID: 1015378
Others  :  TRN: US1102898

学科分类：核物理和高能物理

美国|英语

来源: SciTech Connect

【 摘 要 】

To exceed fields of 10 T in accelerator magnets, brittle superconductors like A15 Nb{sub 3}Sn and Nb{sub 3}Al or ceramic High Temperature Superconductors have to be used. For such brittle superconductors it is not their maximum tensile yield stress that limits their structural resistance as much as strain values that provoke deformations in their delicate lattice, which in turn affect their superconducting properties. Work on the sensitivity of Nb{sub 3}Sn cables to strain has been conducted in a number of stress states, including uniaxial and multi-axial, producing usually different results. This has made the need of a constituent design criterion imperative for magnet builders. In conventional structural problems an equivalent stress model is typically used to verify mechanical soundness. In the superconducting community a simple scalar equivalent strain to be used in place of an equivalent stress would be an extremely useful tool. As is well known in fundamental mechanics, there is not one single way to reduce a multiaxial strain state as represented by a 2nd order tensor to a scalar. The conceptual experiment proposed here will help determine the best scalar representation to use in the identification of an equivalent strain model.