@ARTICLE{,
  author = {O'Neil, Galen and Beeks, Kjeld and Hudson, Eric and Jeet, Justin and Leibrandt, David and Mallweger, Marion and Nam, Sae Woo and Patra, Sayan and Porat, Gil and Reddy, Dileep and Schumm, Thorsten and Schoun, Stephen B. and Seiferle, Benedict and Schneider, Christian and von der Wense, Lars and Thirolf, Peter G. and Verma, Varun and Ye, Jun and Zhang, Chuankun},
  title = {Direct detection of the $\approx \unit[8.4]{eV}$ internal conversion energy of $^{229m}\text{Th}$ embedded in a superconducting nanowire},
  journal = {Phys. Rev. C},
  year = {2025},
  volume = {112},
  pages = {024322},
  month = {Aug},
  url = {https://link.aps.org/doi/10.1103/9v5w-b8k2},
  doi = {10.1103/9v5w-b8k2},
  abstract = {We report on a direct measurement of the $\approx \unit[8.4]{eV}$ nuclear excitation energy of the isomeric first-excited state $^{229m}\text{Th}$ via the internal conversion (IC) decay channel. Thermalized and mass-filtered recoiling $^{229m}\text{Th}$ ions from $^{233}U$ $\alpha$ decay are delivered to the surface of a superconducting nanowire sensor and become embedded. The ion is neutralized, triggering the IC decay, and the energy released by the IC decay is detected with high quantum efficiency by the nanowire sensor. Energy resolution is enabled by the current dependence of the internal quantum efficiency of the nanowire sensor. The techniques presented here are complementary to light-based detection schemes. The IC decay channel is about eight orders of magnitude faster than the photoemission channel, thus the ability to detect IC decays with high efficiency with superconducting nanowire sensors is likely to be a valuable tool for future $^{229m}\text{Th}$ experiments.}
}