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Abstract

The ^229mTh isomeric state at approximately 8:28 eV has generated significant interest as a
possible candidate for the development of a nuclear clock with cutting edge precision and stability.
One of the approaches to build such a clock relies on the excitation of thorium nuclei doped
into VUV-transparent crystals. Excitation in the crystal environment has yet to be achieved
experimentally. In this dissertation we investigate from the theoretical side, two methods aimed
at exciting thorium's isomeric state within the crystal environment. We study first the possibility
to carry out nuclear forward scattering style experiments which could provide a unique signature
of the nuclear excitation along with quantifying the detuning of the driving laser systems to the
transition energy in question. This work includes analysis of the phase difference and time delay
between excitation pulses along with the role of magnetic fields and dopant orientations on the
level schemes available for driving. As a second method we investigate Electronic Bridge (EB)
processes within the crystal environment which have never been addressed so far in the literature.
EB exploits the coupling between the nucleus and the electronic shell which is neglected in the
direct laser excitation approach. Novel EB schemes in the crystal environment are introduced
which aim to increase the isomeric population with the use of broadband excitation sources. Rates
of such EB processes are calculated and their advantages with respect to the direct laser excitation
are discussed. These findings support the development of a solid-state nuclear clock.