Experiments to investigate phonon-nuclear interactions

This thesis presents a series of experiments conducted by the author between 2016 and 2018 that were designed to test for and investigate a proposed phonon-nuclear coupling interaction and an associated nuclear excitation transfer mechanism. Electric and magnetic interactions of phonons with atomic nuclei have been studied for several decades. However, such second-order interactions are too weak to induce nuclear state changes. Hagelstein and Chaudhary recently identified the possibility of a stronger, first-order phonon-nuclear interaction, based on the boost correction associated with the nucleon-nucleon potential for nuclei embedded in a condensed matter environment. Because the newly proposed interaction follows from the relativistic (Dirac) treatment of nucleons, Hagelstein and Chaudhary refer to this interaction as relativistic phonon-nuclear coupling.