Polarized Xenon Production: Compact Magnetic Field

描述（由申请人提供）：超极化气体（氙-129和氦-3）已证明其在结构和功能肺成像以及量化肺部疾病中的实用性。然而，与氦-3相比，氙便宜且储量丰富。它较低的扩散常数提供了优于氦的科学优势，抵消了其较低的旋磁比的缺点。一个紧凑的，鲁棒的，商业偏振器产生50%的偏振在人类成像的有用数量的可用性将引发广泛的研究和应用超极化氙作为成像剂。UNH小组展示了一种新型的氙偏振器，它使气体混合物以相对较高的速度和沿着与激光束相反的方向流动。这种偏振器表现出对于小批量超过60%的偏振，对于超过4升/小时的生产速率超过20%的偏振。该偏振器的品质因数（偏振乘以生产率）目前超过所有其他偏振器技术一个数量级。增加可用激光功率和低温累积能力的单独STTR项目将使偏振器输出增加6至10倍。极化技术依赖于浸没在均匀的25高斯场中的长极化柱、具有100 ppm均匀性的可调场的NMR区域以及非常强的场累积区域。必须消除这些元件的相互作用，以使系统紧凑。我们的第一阶段STTR项目包括对新型非对称磁导率结构进行数值模拟，以传输、成形和扩展磁场线，从而创建均匀的场体积和区域之间的平滑过渡。它还包括制造原型和测量确认模拟和实现之间的协议。我们完成了数百个设计计算，并制作和表征了2个原型，满足设计要求。在第二阶段，我们建议进一步完善设计以提高性能，将偏振器组件集成到其新的磁环境中，并设计易于访问内部组件，特别是最终的超偏振氙产品。这些发展将把我们的大型实验室原型转化为实用的紧凑型商业化医院设备。

DESCRIPTION (provided by applicant): Hyperpolarized gases, both xenon-129 and helium-3, have demonstrated their utility in structural and functional lung imaging and quantifying lung disease. In contrast to helium-3, however, xenon is cheap and abundant. Its lower diffusion constant offers scientific advantages over helium, offsetting the disadvantage of its lower gyromagnetic ratio. Availability of a compact, robust, commercial polarizer producing 50% polarization in useful quantities for human imaging would trigger widespread investigations and applications of hyperpolarized xenon as an imaging agent. The UNH group demonstrated a new type of xenon polarizer that flows the gas mixture at relatively high velocity and low pressure along a direction opposite to the laser beam. This polarizer demonstrated polarization of over 60% for small quantities and 20% for a production rate of over 4 liters per hour. The figure-of-merit (polarization times production rate) of this polarizer presently exceeds all other polarizer technologies by an order of magnitude. Separate STTR projects to increase the useable laser power and to the cryogenic accumulation capacity would increase the polarizer output by another factor of 6 to 10. The polarization technology relies on a long polarization column immersed in a uniform 25 gauss field, an NMR region with adjustable field having 100 ppm uniformity, and a very strong field accumulation region. The interaction of these elements must be eliminated to make the system compact. Our Phase 1 STTR project included numerical simulation of novel asymmetric permeability structures to transport, shape, and spread magnetic field lines creating uniform field volumes and smooth transitions between regions. It also included fabrication of prototypes and measurements confirming the agreement between simulation and realization. We completed several hundred design calculations and fabricated and characterized 2 prototypes, meeting the design critera. In Phase II we propose to further refine the design for improved performance, intergrate the polarizer components into their new magnetic environment, and engineer for ease of access to internal components particularly the final hyperpolarized xenon product. These developments will convert our large laboratory prototype into a practical compact commercially-available hospital-based device.