波谱学杂志2026，Vol.43Issue(3)：268-278,11.DOI:10.11938/cjmr20263206
低场永磁磁共振系统高稳定匀场电流放大器设计
A High-stability Shimming Current Amplifier Design for Low-field Permanent Magnet NMR Systems
摘要
Abstract
The widespread application of low-field permanent magnet NMR systems in areas such as food testing and material analysis places higher demands on the quality of NMR signals.Magnetic field uniformity is crucial for obtaining high-quality signals,and the performance of the shimming current amplifier directly determines the effectiveness of active shimming.This paper presents a specialized high-stability,low-ripple shimming current amplifier design for high-resolution,low-field permanent magnet NMR systems.The design employs a highly integrated modular architecture,supports multi-channel expansion via controller area network(CAN)communication,and utilizes a self-biased push-pull circuit to achieve bipolar current output from-1 A to+1 A,significantly improving output linearity.To ensure accuracy and stability,differential sensing is applied in the current feedback loop to effectively suppress common-mode noise.The amplifier demonstrates a linear regression coefficient R²>0.999 999 9 and a 48-hour long-term stability of 5.3 ppm(1 ppm=10-6),enabling precise current control with excellent linearity and stability,thereby meeting the driving requirements of shim coils in high-resolution,low-field NMR systems.关键词
低场磁共振/永磁磁体/匀场电流放大器/电流源/稳定性Key words
low-field NMR/permanent magnet/shimming current amplifier/current source/stability分类
数理科学引用本文复制引用
卢星云,姚守权,徐俊成,蒋瑜..低场永磁磁共振系统高稳定匀场电流放大器设计[J].波谱学杂志,2026,43(3):268-278,11.基金项目
上海市科技创新行动计划资助项目(19142202900) （19142202900）
国家自然科学基金资助项目(21874045). （21874045）
