波谱学杂志 ›› 2016, Vol. 33 ›› Issue (3): 458-467.doi: 10.11938/cjmr20160311

• 低场磁共振技术与应用专栏 • 上一篇    下一篇

超极化气体氙-129的低场NMR测量

赵修超1,2, 孙献平1, 袁亚平1,2, 石磊1, 叶朝辉1, 周欣1   

  1. 1. 波谱与原子分子物理国家重点实验室, 武汉磁共振中心(中国科学院 武汉物理与数学研究所), 湖北 武汉 430071;
    2. 中国科学院大学, 北京 100049
  • 收稿日期:2015-10-22 修回日期:2016-07-10 出版日期:2016-09-05 发布日期:2016-09-05
  • 通讯作者: 周欣,电话:027-87198802,E-mail:xinzhou@wipm.ac.cn. E-mail:xinzhou@wipm.ac.cn
  • 作者简介:赵修超(1986-),男,山东临沂人,博士研究生,原子分子物理专业.
  • 基金资助:

    国家自然科学基金资助项目(81227902,11174327).

Measuring Polarization of Hyperpolarized Xenon-129 Gas with Low-Field NMR

ZHAO Xiu-chao1,2, SUN Xian-ping1, YUAN Ya-ping1,2, SHI Lei1, YE Chao-hui1, ZHOU Xin1   

  1. 1. State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan (Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences), Wuhan 430071, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2015-10-22 Revised:2016-07-10 Online:2016-09-05 Published:2016-09-05

摘要:

在自旋交换光泵过程中,多种参数可能会影响到最终可获得的超极化气体氙-129核自旋极化度.通过低场(0.002 T)核磁共振(NMR)系统研究了连续流动工作模式的自旋交换光泵过程,当混合工作气体流量为0.3 SLPM和0.5 SLPM时,实验测量得到最佳光泵泡工作温度;对于同位素富集和自然丰度的氙-129气体,核自旋极化度的建立时间分别为15 min和22 min.由于混合工作气体的压力以及组分会导致铷原子吸收线的频移和展宽,并且影响到其线型,实验通过低场NMR系统测量确定了用于自旋交换光泵的最佳激光工作波长.低场NMR测量为获得具有高核自旋极化度的超极化气体氙-129,并且能够用于人体肺部MRI研究提供了实验依据.

关键词: 低场核磁共振, 超极化气体氙-129, 自旋交换光泵

Abstract:

Polarization of hyperpolarized xenon-129 gas prepared by spin exchange optical pumping (SEOP) is affected by many operating parameters. In this study, we measured polarization of hyperpolarized xenon-129 gas on a low field (0.002 T) NMR system, and used the results of such measurements to optimize the operating parameters of SEOP. The optimal operating temperature was first determined. Then the optimal building time for isotopically enriched and naturally abundant xenon-129 gases was determined to be 15 min and 22 min, respectively. The pressure and composition of the gases in the optical pumping process were then optimized to minimize spectral shift, broadening and lineshape change of the rubidium atom absorption lines. Finally, the optimal laser wavelength was determined. In conclusion, measuring polarization of hyperpolarized xenon-129 gas with low-field NMR provides an experimental basis for optimizing operating parameters of SEOP.

Key words: low filed NMR, hyperpolarized xenon-129 gas, spin exchange optical pumping

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