paper

Radiative Decay of the $^{229 m}$ Th Nuclear Clock Isomer in Different Host Materials

arXiv:2408.12309 · doi:10.1103/PhysRevResearch.7.013052

Abstract

A comparative vacuum ultraviolet spectroscopy study conducted at ISOLDE-CERN of the radiative decay of the $^{229 m}$ Th nuclear clock isomer embedded in different host materials is reported. The ratio of the number of radiative decay photons and the number of $^{229 m}$ Th embedded are determined for single crystalline CaF $_{2}$ , MgF $_{2}$ , LiSrAlF $_{6}$ , AlN, and amorphous SiO $_{2}$ . For the latter two materials, no radiative decay signal was observed and an upper limit of the ratio is reported. The radiative decay wavelength was determined in LiSrAlF $_{6}$ and CaF $_{2}$ , reducing its uncertainty by a factor of 2.5 relative to our previous measurement. This value is in agreement with the recently reported improved values from laser excitation.

Radiative Decay of the 229mTh Nuclear Clock Isomer in Different Host Materials

Abstract

Radiative Decay of the $^{229 m}$ Th Nuclear Clock Isomer in Different Host Materials