Laser excitation and conversion-electron detection in ThO2 thin films

Investigate and demonstrate laser excitation of the 229mTh nuclear isomeric transition in thorium dioxide (ThO2) thin films produced via pyrohydrolysis of ThF4 and evaluate observation of the transition through internal conversion electrons to enable a conversion-electron-based nuclear clock.

Background

The authors developed a pyrohydrolysis procedure converting ThF4 films to ThO2, motivated by the potential advantages of ThO2 (cubic symmetry, vanishing electric field gradients) for conversion-electron-based nuclear clock implementations.

However, they note that laser excitation in ThO2 thin films, potentially observable via conversion electrons, has not yet been demonstrated and requires future experimental work.