October 2, 2025Open Access

Theoretical evaluation of decay mode of ^229m Th in solid samples

Key Points

Decay modes depend on the electronic states of thorium-229m, revealing crucial insights into its half-life.
DFT calculations show varied decay mechanisms; γ-ray transitions occur in most samples, with exceptions noted.
Ion trap and solid-state configurations are linked to distinct decay pathways for thorium-229m, emphasizing complexity.
Findings highlight the need for further investigation into electronic states in solid samples for accurate decay modeling.

Abstract

The excitation energy of ^229m Th is extremely low at 8. 4 \, eV ; thus, this isotope exhibits changes in its decay modes depending on the chemical state, specifically the outermost electronic states. However, the reported half-lives of γ-ray transition are not consistent among the previous experiments. In this study, we investigate the chemical states of ^229m Th by DFT calculations. Based on these results, we evaluate the relationship between the experimental half-life for each sample and the electronic state of Th. The calculation results indicate that ion trap method, Ca F₂ model and Mg F₂ one decay only via the γ-ray transition, whereas Li Sr Al F₆ decay via the γ-ray transition and has a possibility of decay via internal conversion, and electron bridge.

Read Full Paperexternally

Bookmark

View Full Paper

Cite This Study

Masuda et al. (Fri,) studied this question.

synapsesocial.com/papers/68de5d9c83cbc991d0a202de https://doi.org/https://doi.org/10.48550/arxiv.2507.09064

Also Consider

Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context:

Bookmark

View Full Paper