Design and Implementation of An Active Shimming System for Low Field NMR Analyzers

doi:10.11938/cjmr20170111

Abstract

Abstract: High homogeneity of the magnet field is an essential prerequisite for measuring weak signals and short spin-spin relaxation time on a nuclear magnetic resonance (NMR) analyzer. In this study, we designed active shimming coils, based on a target-field approach, for low filed NMR analyzers. Constant current source was designed according to the coil power supply. An active shimming platform used in a NMR analyzer's 0.45 T magnet system was constructed over a large target-diameter-sphere-volume (25.4 mm DSV) of interest. The basic structure and operation principles of the system, as well as the shimming method, were introduced. The feasibility and practicality of the design was demonstrated by experimental measurements.

Key words: constant current source, free induction decay (FID), target-field approach, low-field NMR, active shimming

CLC Number:

CHEN Shan-shan, XIA Tian, BI Xin, MIAO Zhi-ying, YANG Pei-qiang, WANG Hong-zhi, DAI Shu-guang. Design and Implementation of An Active Shimming System for Low Field NMR Analyzers[J]. Chinese Journal of Magnetic Resonance, 2017, 34(1): 87-99.

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