Photo-Induced Quenching of the 229Th Isomer in a Solid-State Host

TL;DR

This study investigates how laser-induced VUV radiation causes the relaxation of the 229Th isomer in a solid host, revealing a photoquenching process with measurable cross-sections and a proposed decay model.

Contribution

It introduces the first measurement of the photoquenching cross-section of the 229Th isomer in a solid-state environment and presents a model explaining the decay mechanism.

Findings

Photoquenching occurs under off-resonant VUV illumination.

Measured cross-section for photoquenching is provided.

A decay model involving electronic states within the bandgap is proposed.

Abstract

The population dynamics of the 229Th isomeric state is studied in a solid-state host under laser illumination. A photoquenching process is observed, where off-resonant vacuum-ultraviolet (VUV) radiation leads to relaxation of the isomeric state. The cross-section for this photoquenching process is measured and a model for the decay process, where photoexcitation of electronic states within the material bandgap opens an internal conversion decay channel, is presented and appears to reproduce the measured cross-section.