Conceptual Design of 3-T All HTS MRI Using No-Insulation Winding Technology: Electromagnetic Stress Reinforced Structure

Once the miniaturization of high-performance magnetic resonance imaging (MRI) scanner was accomplished, extremely stringent indexes were needed for the magnetic field, the operational stability and mechanical strength. We adopted “No-insulation (NI) winding technology” to build high-temperature superconducting (HTS) magnets for 3-T grade MRI, in order to achieve these stringent indexes. To realize a compact size of 3-T MRI, the electromagnetic stress of HTS magnet becomes a technical challenge. In this paper, we investigated the construction of an electromagnetic stress reinforced structure for HTS magnets of 3-T MRI. First, the electromagnetic force was estimated, and the distributions of stress and strain induced by electromagnetic force in the winding part of the HTS magnet were reproduced using a finite element analysis. Meanwhile, the influences of the interlayers between sub-coils, shells and blind flanges on the stress property of HTS magnet were evaluated. Based on these results, the material and its consumed volume established the reinforced structure employed of the HTS magnet were also clarified. Finally, the utility of reinforced structure was verified for NI HTS magnets deployed in 3-T MRI.