Study on the Electromagnetic Characteristics of Ring-Shaped Superconducting Permanent Magnets for Medical Applications

Abstract

The ring-shaped superconducting permanent magnet, with its great advantages in flexible sizing and trapped field, has become a potential candidate for portable medical applications. However, due to the complex geometry involved, it is difficult to predict its electromagnetic performance by traditional numerical methods. This paper presents a field-circuit coupling method to study the entire magnetization process of the ring-shaped magnet. Firstly, the principle of the numerical method is introduced and it is proved to be sufficient for a ring-shaped magnet with a large turn number. Then, the numerical model is used to discuss the relationship between pulse waveform and magnitude of trapped field. Next, the accumulation effect under multi-pulse magnetization is theoretically analyzed and proved by both experiments and simulation. Finally, based on the numerical model, a study on the decay process of ring-shaped magnets is also presented. Conclusions from this paper will be helpful for obtaining the optimization strategy of magnetization of ring-shaped magnets for practical medical applications.