The Spin Transition and Susceptibility of NMR Samples in a Time Dependent Longitudinal Field

• 作者: Bin Xu Hong Ma Jinbo Li Yifan Hu
• 来源期刊: 现代物理(英文)
• 学科: 医学
• 关键词: NMR PROBE SPIN Transition SUSCEPTIBILITY Time Dependent Longitudinal FIELD
• 年，卷（期）: 2012,（11）
• 页码范围: 1732-1736
• 页数: 5页
• 分类号: R73

摘要

To construct pulsed high magnet, with rapid adjustments to large changes in the field strength, it is a mandatory acces-sory to development a special NMR probes to provide a precise real-time map of the magnetic field. In order to do so, it is necessary to understand the variations of the spin transition and susceptibility of NMR samples in a time dependent longitudinal field. This work analyzes the effect on the spin transition by a time dependent longitudinal field. For a 1/2 spin system, we have derived a simple formula for the prediction of the probabilities of occupation of the 1/2 and ?1/2 states in a non-static field. We also calculate the magnetic susceptibility of the water and give an analysis of the effect on the magnetic susceptibility in a time dependent longitudinal field and RF frequency.