Radioluminescence and photoluminescence of Th:CaF${}_2$ crystals

Abstract

We study thorium-doped CaF${}_2$ crystals as a possible platform for optical spectroscopy of the Th-229 nuclear isomer transition. We anticipate two major sources of background signal that might cover the nuclear spectroscopy signal: VUV-photoluminescence, caused by the probe light, and radioluminescence, caused by the radioactive decay of Th-229 and its daughters. We find a rich photoluminescence spectrum at wavelengths above 260 nm, and radioluminescence emission above 220 nm. This is very promising, as fluorescence originating from the isomer transition, predicted at a wavelength shorter than 200 nm, could be filtered spectrally from the crystal luminescence. Furthermore, we investigate the temperature-dependent decay time of the luminescence, as well as thermoluminescence properties. Our findings allow for an immediate optimization of spectroscopy protocols for both the initial search for the nuclear transition using synchrotron radiation, as well as future optical clock operation with narrow-linewidth lasers.

9 pages, 6 figures

References in corpus (6)

• Systematic evaluation of an atomic clock at 2e-18 total uncertainty
• Enhanced effect of temporal variation of the fine structure constant in diatomic molecules
• Proposal for a Nuclear Gamma-Ray Laser of Optical Range
• Performance of a 229 Thorium solid-state nuclear clock
• Excitation of the isomeric ^{229m}Th nuclear state via an electronic bridge process in ^{229}Th^+
• Coherence-enhanced optical determination of the ${}^{229}$Th isomeric transition

Cited by in corpus (19)

• Direct detection of the 229Th nuclear clock transition
• Frequency ratio of the ${}^{229\mathrm{m}}$Th nuclear isomeric transition and the ${}^{87}$Sr atomic clock
• Observation of the radiative decay of the ${}^{229}\mathrm{Th}$ nuclear clock isomer
• Radiative lifetime and energy of the low-energy isomeric level in ${}^{229}$Th
• A laser excitation scheme for ${}^{229\text{m}}$Th
• Nuclear excitation of the ${}^{229}$Th isomer via defect states in doped crystals
• The ${}^{229}$Th isomer: prospects for a nuclear optical clock
• On an attempt to optically excite the nuclear isomer in Th-229
• Controlling ${}^{229}$Th isomeric state population in a VUV transparent crystal
• An alternative approach to populate and study the ${}^{229}$Th nuclear clock isomer
• Towards a 229Th-based nuclear clock
• Measuring the Th-229 nuclear isomer transition with U-233 doped crystals
• Optomechanically induced transparency of x-rays via optical control
• Driven electronic bridge processes via defect states in ${}^{229}$Th-doped crystals
• Anomalous Hyperfine Structure of the ${}^{229}$Th Ground-State Doublet in Muonic Atom
• Experimental studies of thorium ions implantation from pulse laser plasma into thin silicon oxide layers
• Collective effects in ${}^{229}$Th-doped crystals
• Proposal for a Nuclear Light Source
• Production and chemical separation of ${}^{229}$Pa toward observation of $\gamma$ rays of ${}^{229\mathrm{m}}$Th