Speaker
Description
A magnet undergoing a quench is one of the most challenging scenarios for any operator, often leading to potential failure of the magnet. While quench phenomena are well understood in LTS magnets—where manufacturers deliberately induce quenches during commissioning to ensure reliability—the same cannot be said for HTS magnets. Challenges such as the slow propagation of the normal zone and a significant operating temperature margin before transitioning to the non-superconducting state make quench detection and active protection methods for HTS magnets less effective, particularly in high-field applications.
Given these limitations, designing passively quench-tolerant magnets emerges as a more practical approach. In this work, we present two modelling techniques developed at OpenStar Technologies for the levitating non-insulated DC magnet: (1) a circuit-based modelling approach and (2) a finite element method (FEM) approach. Both methods incorporate a multi-physics framework, with the circuit model offering a fast and simplified analysis, while the FEM approach provides a slower but more detailed simulation.
These models were specifically tailored to mimic OpenStar’s Junior core magnet, comprising of 14 solder-impregnated, thermally coupled coils. The results from both models were consistent with each other and validated against experimental data, demonstrating their reliability.
We further leveraged these tools to explore design enhancements for the next generation of quench-tolerant magnets. Key findings include the significance of non-uniform coil time constants, optimal placement of thermal masses, and effective thermal routing. While these insights may seem intuitive, they are critical in identifying and addressing design bottlenecks without compromising structural integrity.
Currently, the models couple electro-thermal and magnetic physics. Future work aims to incorporate structural mechanics to develop fully optimized magnet designs tailored to specific application requirements.
