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

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

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.