圆柱型Halbach永磁魔环研究进展  

Research Progress of Cylindrical Halbach Permanent Magnet Magic Ring

作　　者：张鞠成 王志康[1] 娄海芳[1] 黄天海[1] 张华青[1] 徐文龙[2] 

机构地区：[1]浙江大学医学院附属第二医院临床医学工程部,浙江杭州310009 [2]中国计量学院信息工程学院,浙江杭州310018

出　　处：《航天医学与医学工程》2015年第2期151-156,共6页Space Medicine & Medical Engineering

基　　金：国家自然科学基金(81101031);国家质检公益性行业科研项目(201210079);浙江省科技厅项目(2014C37074)

摘　　要：受局部饱和和局部退磁效应的影响以及磁材料性能的限制,永磁体的气隙磁场一般难以达到4T。Halbach永磁魔环结构磁材料利用效率高,且能够产生比剩磁更高的静磁场,因而近年来在磁共振成像领域得到了广泛关注。本文针对Halbach永磁魔环的构成形式,介绍了永磁魔环、阵列永磁魔环、永磁双魔环和单边永磁魔环的研究现状,分析了这些魔环结构由于永磁磁块形状、尺寸,永磁材料受温度变化影响,和加工工艺等因素引起的磁场均匀性较差等主要问题,并对圆柱型Halbach永磁魔环在NMR、MRI和便携式分析仪器等方面的应用进行了展望。Field strength exceeding 4 Tesla in the magnet gap is hard to achieve for permanent magnet because of abnormal magnetizations including local saturation and local demagnetization and the limitation of properties of magnetic materials. Halbach type permanent magnets are of high magnetic material utilization efficiency and can produce homogeneous static field which is greater than the remanence of permanent magnet,thus have drawn wide attention in magnetic resonance imaging. This paper summarized the status and progress of cylindrical Halbach permanent magnet magic ring of different structures,including conventional,Mandhalas,nested and single-sided Halbach permanent magnets. The poor magnetic homogeneity caused by permanent magnet shape,dimension,temperature dependence of the remnant magnetization and work process was discussed.The development trend of cylindrical Halbach permanent magnet magic ring in NMR,MRI and portable analytical instrument was also prospected.

关 键 词：磁共振成像 HALBACH阵列 永磁魔环 永磁体 

分 类 号：TM273[一般工业技术—材料科学与工程]