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Abstract：High field magnetic resonance imaging (HF-MRI) systems can achieve higher image resolution and sensitivity, resulting in better image quality and more biological information, which has significant value in life science and clinical medicine applications. The key to high field magnetic resonance imaging systems is the high homogeneous superconducting magnets, and active homogenization coils can help to achieve high homogeneous superconducting magnets. This article introduces the design and development process of active shimming coils for 7T whole-body MRI superconducting magnets. Based on the initial magnetic field homogeneity of the 7T superconducting magnet, according to analytical method, the positions of three groups of solenoid shimming coils Z1, Z2, and Z3 were calculated, as well as the linear distribution of six groups of saddle shaped shimming coils X, Y, ZX, ZY, X2Y2, and X-Y. The homogeneity compensation ability, coil current, and electromagnetic stress of each group of shimming coils were calculated in this article. The maximum compensation ability of Z1/Z2/Z3 was 125ppm, the maximum current was 5A, and the maximum electromagnetic stress was 120MPa. The skeleton of the active homogenization coil was designed, made of epoxy material G10, and the stress and deformation of the skeleton were analyzed using finite element method. The results showed that the maximum stress of the skeleton was 41.3 MPa and the maximum deformation was 0.141 mm. The coil design meets the project requirements, and the active shimming coil of the 7T whole-body MRI superconducting magnet is feasible.
Index Terms：High Field MRI（HR-MRI），7T，Superconducting Magnet，Active Shimming Coil，Homogeneity，Compensation Capacity，Electromagnetic Stress
