학술논문

Modeling Training in Nb3Sn Superconducting Magnets
Document Type
Periodical
Source
IEEE Transactions on Applied Superconductivity IEEE Trans. Appl. Supercond. Applied Superconductivity, IEEE Transactions on. 34(5):1-5 Aug, 2024
Subject
Fields, Waves and Electromagnetics
Engineered Materials, Dielectrics and Plasmas
Superconducting magnets
Magnetomechanical effects
Magnetic separation
Training
Temperature measurement
Computational modeling
Coils
CCT
debonding
++%24%5F3%24<%2Ftex-math>+<%2Finline-formula>+<%2Fnamed-content>Sn%22">Nb $_3$ Sn
training
Language
ISSN
1051-8223
1558-2515
2378-7074
Abstract
Stress managed magnet designs allow to limit the strain and stresses applied to the conductor during assembly and operation. In canted cos($\theta$) (CCT) designs, the conductor is wound around a mandrel: the impregnation process creates a bonding between the two, that can fail during magnet powering. The energy releases due to debonding are considered a potential cause of training quenches. In this study, we investigate these events modeling the mandrel-conductor interfaces by means of cohesive zone material models. The material properties were calibrated by means of measurements performed on representative interfaces, and the models were validated comparing the results with strain gauge measurements. A thermal model was used to compute the local temperature increase in the strands as a function of the energy released by debonding and frictional sliding across the newly formed interfaces. The result was then used to define a quench condition for the model, allowing to simulate the full training process of the CCT magnet. The obtained training curve is in reasonable agreement with the experimental results.