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Investigation of a new model of dipolar-coupled nuclear spin relaxation and applications of dynamic nuclear polarization.

机译：研究偶极耦合核自旋弛豫的新模型及其动态核极化的应用。

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摘要

This work presents the results of various investigations using various techniques of hyperpolarizing the nuclei of atoms. Hyperpolarization implies magnetic order in excess of the thermal order obtained naturally as described by Curie's law.;The main portion of this work presents the results of a detailed experimental exploration of predictions arising from a new model of transverse nuclear spin relaxation in quantum systems, based on possible manifestations of microscopic chaos in quantum systems. Experiments have been carried out on a number of hyperpolarized xenon samples, each differing in its relative percentage of xenon isotopes in order to vary the homonuclear and heteronuclear dipole couplings in the spin system. The experiments were performed under a variety of conditions in an attempt to observe the behaviors predicted by the model. Additionally, much more extensive measurements were made on a number of samples of solid CaF2 in both single crystal and powder forms. These samples, although thermally polarized, were observed with superior signal to noise ratios than even the hyperpolarized xenon solids, allowing for more precise measurements for comparison to the theory. This work thus contains the first experimental evidence for the majority of the model's predictions.;Additionally, this work contains the first precise measurements of the frequency-shift enhancement parameters for 129Xe and krypton in the presence of spin-polarized Rb. The determination of these important numbers will be useful to many groups who utilize spin-exchange optical pumping in their labs. This work built on the prior knowledge of a precise number for the frequency-shift enhancement parameter of 3He in Rb vapor.;Finally, I detail work using NMR to detect nuclear-spin polarization enhancement in silicon phosphorus by a novel, photo-induced hyperpolarization technique developed by the Boehme research group at the University of Utah. Significant nuclear polarization enhancements were observed by the Boehme group due to electron-photon interactions in semiconductor soilds; these enhancements were observed by their effects on the ambient electrons and measured with electron spin resonance techniques. The work described here details experiments to observe the enhanced nuclear polarization by directly measuring the intensity increase in an NMR measurement.;I will conclude this dissertation with a brief appendix giving a summary of one additional project involving the use of high pressure fluorinated gas NMR to measure the internal topology and characteristics of energy-rich oil shales.
机译：这项工作提出了使用超极化原子核的各种技术进行各种研究的结果。超极化意味着磁阶超过了居里定律所描述的自然获得的热阶。这项工作的主要部分是对量子系统中横向核自旋弛豫新模型所产生的预测进行详细实验探索的结果。关于量子系统中微观混沌的可能表现。为了改变自旋系统中的同核和异核偶极偶合，已经对许多超极化氙样品进行了实验，每个样品的氙同位素相对百分比不同。为了观察模型预测的行为，在各种条件下进行了实验。另外，对许多单晶和粉末形式的固体CaF2样品进行了更广泛的测量。这些样品虽然是热极化的，但观察到的信噪比甚至比超极化的氙气固体还要好，从而可以进行更精确的测量以与理论进行比较。因此，这项工作为模型的大部分预测提供了第一个实验证据。此外，这项工作还包含了在存在自旋极化Rb的情况下对129Xe和k的频移增强参数的首次精确测量。这些重要数字的确定对于许多在实验室中利用自旋交换光泵浦的小组很有用。这项工作基于对Rb蒸气中3He的频移增强参数的精确数字的先验知识。最后，我详细介绍了使用NMR通过新颖的光诱导超极化来检测硅磷中核自旋极化增强的工作。这项技术是由犹他大学Boehme研究小组开发的。由于半导体污垢中的电子-光子相互作用，Boehme研究小组观察到了显着的核极化增强。这些增强作用是通过它们对周围电子的影响而观察到的，并通过电子自旋共振技术进行了测量。这里描述的工作详细介绍了通过直接测量NMR测量中的强度增加来观察增强的核极化的实验。我将以一个简短的附录结束本论文，总结了涉及使用高压氟化气体NMR的另一个项目的摘要。测量富含能量的油页岩的内部拓扑结构和特征。

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  • 作者

    Sorte, Eric G.;

  • 作者单位

    The University of Utah.;

  • 授予单位 The University of Utah.;
  • 学科 Physics Nuclear.;Physics Atomic.
  • 学位 Ph.D.
  • 年度 2011
  • 页码 176 p.
  • 总页数 176
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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