Investigation of the Low-Lying Nuclear Isomeric Transition in the A = 229 Isotope of Thorium

钍 A = 229 同位素低位核异构转变的研究

• 批准号: 1615233
• 负责人: Eric Hudson
• 金额: $ 18万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1615233&HistoricalAwards=false
• 关键词: Investigation; Low; Lying; Nuclear; Isomeric

This award will support the PI and his group in bringing the techniques of laser physics to a nuclear system with the goal to directly detect and characterize a unique excited state in the A = 229 isotope of thorium. The state is a low lying excited state that is now able to be investigated with current laser technology. The ultimate goal is to use the characteristics of that state to investigate one of the most compelling questions in modern science: Are the constants of nature actually constants? Further, two technological applications with significant impact have also been proposed: a nuclear clock, which could outperform all current and planned optical clocks, thereby improving navigation and communication, and a gamma ray laser in the optical range. Under this award, the PI and his group will perform a direct search for this nuclear transition to better measure the transition energy and lifetime in order to enable the aforementioned promising applications. Specifically, they will interrogate thorium-229 atoms, which have been doped into a vacuum ultraviolet transparent host crystal, with a laser system capable of directly exciting the nuclear state. The resulting nuclear fluorescence will be monitored to determine the transition energy and lifetime. Once the transition is found, the potential of the transition for use as a clock oscillator will be explored by comparing a preliminary thorium clock architecture to more established atomic clocks.

该奖项将支持 PI 及其团队将激光物理技术引入核系统，目标是直接检测和表征钍 A = 229 同位素中的独特激发态。 该态是一种低位激发态，现在可以用当前的激光技术进行研究。 最终目标是利用该状态的特征来研究现代科学中最引人注目的问题之一：自然常数实际上是常数吗？ 此外，还提出了两项​​具有重大影响的技术应用：核钟，其性能优于所有当前和计划中的光学钟，从而改善导航和通信，以及光学范围内的伽马射线激光器。根据该奖项，PI 和他的团队将直接研究这种核跃迁，以更好地测量跃迁能量和寿命，从而实现上述有前景的应用。具体来说，他们将用能够直接激发核态的激光系统来探查掺入真空紫外透明主晶体中的钍229原子。将监测由此产生的核荧光以确定跃迁能量和寿命。一旦找到转变，将通过将初步的钍钟架构与更成熟的原子钟进行比较来探索转变用作时钟振荡器的潜力。