A 7-T Actively Shielded Superconducting Magnet for Animal MRI

An actively shielded superconducting magnet for animal magnetic resonance imaging has been designed and fabricated. It has a warm bore of 210-mm diameter and consists of five concentric solenoid coils made of epoxy-impregnated NbTi/Cu superconductors. The designed center field is 7 T, and the field homogeneity is 2.75 ppm on a 100-mm diameter of sphere volume. The positions of 5 Gs line are located at 2.1 m radially and 2.4 m axially from the magnet center. In the paper, results of the electromagnetic, structural, quench protection, and thermal designs of the magnet are presented.