Design and Performance Analysis of Gradient Coil for High-Field HTS REBCO MRI Magnet

In this study, we designed gradient coils for a 6 T high-temperature superconducting (HTS) MRI magnet and analyzed their effects on the main magnet which was fabricated using rare-earth barium copper oxide (REBCO) conductor. First, we designed a total of 6 coils, which composed the X, Y, and Z gradient and shield coils. To ensure the performance of gradient system, we designed the gradient coil that satisfies the essential requirements such as linearity and uniformity. Second, we analyzed the effects of the gradient coil operations on the main magnet. Although the gradient shield coils prevented the main HTS magnet from experiencing magnetic field changes, the unshielded magnetic field leakage could generate screening currents in the REBCO conductor which could affect the performance of the main magnet. We simulated and analyzed the electromagnetic behaviors of the HTS REBCO magnet affected by the high-frequency varying field caused by the gradient coil operation.