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

该奖项将支持PI和他的团队将激光物理技术引入核系统，目标是直接探测和表征钍的A=229同位素中的一个独特的激发态。这种状态是一种低激发态，现在可以用当前的激光技术进行研究。最终目标是利用这种状态的特征来研究现代科学中最引人注目的问题之一：自然的常量真的是恒定的吗？此外，还提出了两项具有重大影响的技术应用：一种核时钟，其性能可以超过所有现有和计划中的光学时钟，从而改善导航和通信；以及一种在光学范围内的伽马射线激光器。根据这一奖项，PI和他的团队将对这种核跃迁进行直接搜索，以更好地测量跃迁能量和寿命，从而实现上述有希望的应用。具体地说，他们将使用能够直接激发核态的激光系统来询问已经掺杂到真空紫外光透明主体晶体中的钍-229原子。由此产生的核荧光将被监测，以确定跃迁能量和寿命。一旦发现了跃迁，将通过比较初步的钍时钟体系结构和更成熟的原子钟来探索将跃迁用作时钟振荡器的潜力。

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.