UNC-CH Physics and Astronomy Thesis Proposal Presentation

Michele Kelley

“Designing and constructing a high efficiency 129Xe polarizer”

My work thus far indicates two major barriers to producing high levels of 129Xe polarization: first, 129Xe residence times that are much shorter than what is currently assumed; second, and more importantly, a low Rb density with respect to the normally assumed empirical models. These results also suggest that these two effects do not fully account for the discrepancy between theoretical and experimental 129Xe polarization level. To this end, my future work will be focused on first resolving this discrepancy by measuring spin exchange optical pumping rates, which have not been measured previously under the standard experimental conditions used for continuous flow SEOP of 129Xe. Additionally, I will use finite element simulations to design a new optical pumping cell that will extend Xe residence times and increase Rb vapor density. This all will culminate in the construction and characterization of a high efficiency 129Xe polarizer.