Three-Dimensional Numerical Simulation Employing Normal Zone Propagation Velocity on Heat Propagation of LTS Magnet Under Quench Process

Because low-temperature superconducting (LTS) magnets can conduct large electric current and generate intense magnetic fields under cryogenic conditions, such magnets are used in many applications such as MRI, nuclear magnetic resonance spectrometers, and mass spectrometers. However, an abnormal termination called "quench" disturbs the normal operation and increases the magnet temperature. To protect the LTS magnet from excessive heat, the maximum temperature of a magnet under the quench process should be calculated. The design of a superconducting magnet protection system is performed according to the calculated maximum temperature. This is why accurate estimation of magnet temperature is important. The quench process of a superconducting magnet involves complex physical mechanisms, which requires a thermal-electrical simulation using computational analysis. We propose a highly efficient and reliable three-dimensional quench calculation method that can calculate the magnet temperature in the quench process. The LTS magnet is divided into many unit nodes; multiphysics analysis at each node is carried out with respect to the elapsed time. To verify the feasibility of the simulation, LTS magnet quench experimental results were compared with the simulation results. This study has the potential to develop a computational method for heat propagation analysis of a superconducting magnet.