In this paper, a new portable, low-cost magnet with a good homogeneity is presented. The single-layer central magnet structure based on Halbach-type array has been designed, simulated which can generate a magnetic field of 1 T under the weight of 2 kg. Magnetic strips placed at the ends of the central magnet are presented to improve the central homogeneity. In order to counteract the inhomogeneity resulting from manufacturing tolerances, a new compact shimming structure designed for miniature Halbach magnet is applied. With this structure a reduction of the full width at half maximum (FWHM) from 21 kHz to less than only 0.7 kHz, which is adequate for achieving a good NMR relaxation signal. This novel miniature magnet structure has achieved an excellent balance between cost and homogeneity for portable Time Domain NMR.

中文翻译：

---

一种专为便携式时域NMR设计的低成本微型Halbach磁体

本文提出了一种具有良好同质性的新型便携式，低成本磁体。设计并模拟了基于Halbach型阵列的单层中央磁体结构，该结构在2 kg的重量下可产生1 T的磁场。提出了放置在中央磁体末端的磁条，以改善中央均匀性。为了抵消由于制造公差引起的不均匀性，采用了一种为微型Halbach磁体设计的新型紧凑匀场结构。通过这种结构，半峰全宽（FWHM）从21 kHz减小到仅不到0.7 kHz，这足以实现良好的NMR弛豫信号。对于便携式时域NMR，这种新颖的微型磁体结构在成本和均质性之间实现了极好的平衡。