Preliminary Mechanical Analysis of a 9.4-T Whole-Body MRI Magnet

作者：Lankai Li, Junsheng Cheng, Zhipeng Ni, Housheng Wang, Yinming Dai, Qiuliang Wang · 发表于：IEEE Transactions on Applied Superconductivity · 年份：2015 · DOI：10.1109/tasc.2015.2396934 · 被引用次数：37 · 研究领域：Superconducting Materials and Applications、Advanced MRI Techniques and Applications、Atomic and Subatomic Physics Research

A 9.4-T/800-mm superconducting magnet for whole-body magnetic resonance imaging system has been designed and will be constructed from NbTi conductors. Main coils wound on five aluminum alloy formers provide the center field strength of about 9.4 T. In addition, compensation coils wound on another aluminum alloy former are used to improve the field uniformity of the imaging region. The operating point of the inner main coil is very close to the critical properties of its wire, and its temperature margin is about 0.4 K. It is necessary to know the mechanical stress in the main coils during all operating conditions. The mechanical behavior of the main coils during winding, cooldown, and energizing is analyzed. The effects on mechanical disturbances are predicted, and one available method is proposed to reduce premature quench. In addition, the dimension variations and position changes due to pretension, thermal contraction, and magnetic compression are present.