PPhysics Read More The world’s most precise nuclear clock ticks closer to reality11 December 2025 Crucially, it shows that thorium-229 can be studied inside far more common materials than previously thought, removing one…
![FIG. 1. (a) Cut-away rendering of the 229ThO2 target mount. Arrows denote front aperture, window, target, and pyroelectric detector. (b) Rendering of the spectroscopy chamber. (Magenta arrow) Direction of VUV laser propagation. (Yellow arrows) IC electron trajectories from target to detection MCP. (Blue arrows) Background photoelectrons generated from VUV scatter diverted to secondary electrode. (Green arrow) Direction of static B-field used to guide IC electrons. (c) α-spectrum of the 229ThO2 target. (Inset) Photograph of 229ThO2 target used in this study. The peak labeled to 4845 keV corresponds to the dominant α-decay mode of 229Th. The other large peaks correspond to the α-decays of daughter nuclei. The 229Th peak had a FWHM of ∼22 keV, consistent with energy loss through a ∼10 nm sample, as estimated with SRIM [38].](https://www.europesays.com/uk/wp-content/uploads/2025/12/1920_nuclearclockgraphic-380x220.png)