Polarized Xenon Production: Powerful Narrowed Laser

偏振氙气生产：强大的窄激光

• 批准号: 6937496
• 负责人: Jan H Distelbrink
• 金额: $ 9.99万
• 依托单位: XEMED, LLC
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-30 至 2006-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6937496
• 关键词: biomedical device power system; biomedical equipment development; gas; lasers; lung imaging /visualization /scanning; magnetism; optical polarization; respiratory disorder diagnosis; solubility; xenon

DESCRIPTION (provided by applicant): Both hyperpolarized xenon and helium have demonstrated utility in lung imaging and quantifying lung disease. In contrast to helium, however, hyperpolarized xenon has a high solubility in fluids and tissues and a characteristic chemical shift, revealing its microscopic environment in dissolved-phase imaging. An imaging protocol to investigate dissolved-phase imaging in humans could beneficially utilize several breath holds of roughly one liter each of highly polarized gas. The UNH group has developed 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, producing polarization of over 50% for small quantities and 20% for a production rate of over four 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. The 500 torr operating pressure represents a compromise between higher laser absorption (at higer pressure) and faster spin-exchange rates (at lower pressure). Our numerical simulations indicate that output magnetization scales with absorbed laser power, that is, power within a narrow range around the spectral absorption band. Our research group recently commissioned a 115W laser with narrowed O.Snm spectral linewidth, the world's brightest laser at 794.7nm. We request STTR funding to further develop and commercialize high-power spectrally narrowed lasers for spin-exchange optical pumping of hyperpolarized gas. For Phase I we intend to scale up this spectrally narrowed laser technology to over 400W, install it on a suitably adapted xenon polarizer, and confirm that magnetization output is increased at least 4-fold. For Phase II we will increase efficiency and decrease size by theoretical and experimental optimization of the cavity; characterize the performance of individual components and the full laser; develop supply channels with vendors; engineer mechanical stability and adjustability; determine operational limits; and document safety. We can then commercially offer narrowed lasers from 100W to perhaps as high as 800W for spin-exchange polarization of both helium and xenon.

描述（由申请人提供）：超偏光氙气和氦气在肺部成像和肺部疾病量化方面都有应用。然而，与氦相比，超极化氙在流体和组织中的溶解度高，并且具有典型的化学位移，在溶相成像中揭示了其微观环境。一种用于研究人体溶相成像的成像方案可以有效地利用每次大约一升的高极化气体的几次屏气。