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GOALI: Synchronously Pumped NMR Oscillator

GOALI：同步泵浦核磁共振振荡器

基本信息

批准号：
1912543
负责人：
Thad Walker
金额：
$ 44.43万
依托单位：
University of Wisconsin-Madison
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-09-01 至 2024-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1912543&HistoricalAwards=false
关键词：
GOALI Synchronously Pumped NMR Oscillator

项目摘要

This project, a collaborative project between the University of Wisconsin-Madison and scientists and engineers at Northrop-Grumman Corporation, will further develop new concepts in ultrahigh sensitivity nuclear magnetic resonance (NMR). The idea is make precise measurements of the motions of nuclear spins due to magnetic fields, inertial rotations, or hypothetical new spin-dependent forces of nature. It is noteworthy that such measurements have both practical impact (miniature gyroscopes for navigation, for example) and can be used to test new ideas related to dark matter in the universe. This is an example of a potentially practical device that uses basic features of quantum mechanics to make measurements of macroscopic properties of motion. The underlying principles of the project rely on the application of NMR bias magnetic fields in the form of a sequence of short pulses of well-defined areas that act, in concert with time-dependent optical pumping, to allow alkali atoms and noble-gas nuclei to precess at the same frequency despite having magnetic moments that are different by 3 orders of magnitude. Both species are polarized and precess entirely transverse to the bias field. This greatly suppresses the dominant systematic errors that are known to affect traditional designs of such instruments, but retains the benefits of ultra-sensitive readout of the NMR precession using the embedded alkali magnetometer. Estimates of technical noise indicate the system has a potential frequency noise level of better than 10 nHz/sqrt(Hz), with fundamental limits that are much better. Previous work has demonstrated the basic properties of this system; this project will study systematic errors and improve the statistical uncertainties. The system will be tested as a precision NMR gyro, of great interest to the industrial partners, and will be used to set new mass and sensitivity limits in searches for axion-like particles.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目是威斯康星大学麦迪逊分校与诺斯罗普-格鲁曼公司的科学家和工程师之间的合作项目，将进一步开发高灵敏度核磁共振（NMR）的新概念。这个想法是精确测量由于磁场，惯性旋转或假设的新的自旋相关自然力引起的核自旋运动。值得注意的是，这种测量既有实际影响（例如用于导航的微型陀螺仪），也可用于测试与宇宙中暗物质有关的新想法。这是一个潜在的实用设备的例子，它使用量子力学的基本特征来测量运动的宏观性质。该项目的基本原理依赖于NMR偏置磁场的应用，其形式为一系列明确定义区域的短脉冲，与时间相关的光泵浦相一致，以允许碱金属原子和稀有气体原子核以相同的频率进动，尽管磁矩相差3个数量级。这两种物质都是极化的，并且完全横向于偏置场进行进动。这极大地抑制了已知会影响此类仪器的传统设计的主要系统误差，但保留了使用嵌入式碱性磁力计的NMR旋进的超灵敏读出的益处。技术噪声的估计表明，系统的潜在频率噪声水平优于10 nHz/sqrt（Hz），基本限制要好得多。以往的工作已经证明了这个系统的基本属性，这个项目将研究系统误差和改善统计不确定性。该系统将作为一个精密的核磁共振陀螺仪进行测试，工业合作伙伴对此非常感兴趣，并将用于设置新的质量和灵敏度限制，以寻找轴子状粒子。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。