Speaker
Description
A 14 T whole-body MRI superconducting magnet is currently being designed at the Institute of Plasma Physics Chinese Academy of Sciences. The main coils will be wound with the Nb3Sn Rutherford cable-in-channel conductors, actively shielded, and operate at 1634 A to produce a central field of 14 T in an 840 mm warm bore. The magnetic field homogeneity is 5 ppm in a 45cm DSV. The inductance is 441 H and the stored energy is 615 MJ. To generate such a high-field in a large warm bore, the Nb3Sn conductors will experience significant magnetic stress and strain, which may lead to irreversible degradation of critical current. Therefore, mechanical analyses are conducted to assess the mechanical behaviour of the 14 T MRI magnet, at the following load conditions: room-temperature preloading, cool-down from RT to 4.5 K, and operating conditions. Several approaches are being considered to reduce the hoop strain of the Nb3Sn conductors, which will be compared with the experimental result of the tensile strain irreversibility limit.
