Development of Instrumentation for High-Rate Production of Hyperpolarized 3He Gas

描述(申请人提供)：本方案的总体目标是开发一种新颖、快速、坚固和便携式的~3He超极化装置，它将产生~1 L/小时的~3He气体，自旋极化到40%或更高。该装置将使用亚稳态交换光学泵浦方法(MEOP)，这是一个理论上有利的过程，传统上很难实现。压缩机和激光技术的最新进展克服了这些障碍。基于MEOP工艺的偏振器与目前基于另一种自旋交换光学泵浦方法(SEOP)的偏振器技术相比，将使超极化~3He的产生速度提高近十倍。该设备将是美国第一台专门用于生物医学核磁共振的MEOP 3He超极化设备，可以安装在生物医学成像环境中。这一多学科计划连接了物理和生物医学科学，具有在肺生理学和医学方面提供重大突破性研究的潜力。因此，该计划符合R-21资助机制的条件。该计划的具体目标是： 1.设计并制作了一台采用亚稳态交换光泵浦法工作的~3He超极化装置，每小时产生~1 L的40%偏振~3He气体。 2.确定装置的最佳操作条件，研究~3He偏振信号随操作参数的变化，包括混合气体、压力和压缩速率。 3.用MEOP~3He超极化装置产生的气体进行体模~3He磁共振研究。

DESCRIPTION (provided by applicant): The broad objective of this proposal is to develop a novel, rapid, robust and portable 3He hyperpolarization apparatus that will produce ~ 1 L / hour of 3He gas spin-polarized to 40% or greater. The apparatus will use the metastability-exchange optical pumping method (MEOP), a theoretically-favorable process that has traditionally been difficult to implement. Recent advances in compressor and laser technology have overcome these hurdles. A polarizer based on the MEOP process will provide an almost ten-fold increase in production rate for hyperpolarized 3He when compared to current polarizer technology based on the alternative spinexchange optical-pumping method (SEOP). The proposed apparatus will be the first MEOP 3He hyperpolarization apparatus dedicated to biomedical MRI use in the US and which can be located in the biomedical imaging environment. This multidisciplinary program bridges the physical and biomedical sciences, with the potential to provide significant breakthrough research in pulmonary physiology and medicine. Thus this program qualifies for the R-21 funding mechanism. The Specific Aims of the program are: 1. Design and fabricate a prototype 3He hyperpolarization apparatus that operates using the metastabilityexchange optical pumping (MEOP) method, and produces ~ 1 L per hour of 40% polarized 3He gas. 2. Determine optimum operating conditions for the apparatus, studying 3He polarization signal as a function of operating parameters, including gas mixture, pressure, and compression rate. 3. Perform phantom 3He MRI studies with gas from the MEOP 3He hyperpolarization apparatus.