A study on the optimized design of low-order shimming coils for high-temperature superconducting magnets

In this paper we present design and optimization of shimming coils to correct low-order field gradient components deteriorated by screening currents in high-temperature superconducting (HTS) NMR magnets. The unique geometry of HTS wires induces screening currents, which generate low-order field gradients that degrade the magnetic field quality. To compensate the low-order field gradients, high-strength low-order shimming coils were designed. At first, the target field method was employed to derive the initial shapes of the shimming coils. Subsequently, a genetic algorithm (GA) was utilized to optimize the coil geometries, ensuring ease of fabrication while maintaining high performance. The performance of the optimized coils was validated through virtual field mapping and COMSOL simulations, demonstrating their effectiveness in compensating for targeted gradients with correction efficiencies exceeding 99%. The experimental evaluation will be carried out following the fabrication of the shimming coil in accordance with the proposed design. KCI Citation Count: 0