Pulse field magnetization of high-temperature superconductor bulk parts considering thermal effects
Résumé
The dynamic response of cylindrical and ring-shaped YBaCuO bulk parts to magnetic field variations is calculated using the finite difference method. The computations are based on the heat diffusion equation with account of the heat produced by flux motion, and Maxwell's equations. A power law with temperature and field dependent critical current density is used to characterize the electromagnetic behaviour of the superconducting material. Numerical simulations showed that a major difference is obtained by taking account of the thermal heating. Transient magnetizations as a function of time and space as well as shapes and temperature profiles are reported. The influence of several parameters including peak fields, pulse durations, and geometries are investigated for different magnetization processes. Comparisons concerning the achievable trapped magnetic field are made, and implications for the use of high-temperature superconductor bulk parts as cryo-permanent magnets in potential applications like electric machinery are discussed.