{
  "id": 3086707,
  "title": "Mapping thorium's preferred sites could pave the way for nuclear clocks",
  "url": "https://urgent.news/2026/08/24/mapping-thoriums-preferred-sites-could-pave-the-way-for-nuclear-clocks",
  "topic": "science",
  "section": "Science",
  "published": "2026-08-24T18:40:04.000Z",
  "source": {
    "name": "Phys.org",
    "slug": "phys-org",
    "url": "https://phys.org/news/2026-08-thorium-sites-pave-nuclear-clocks.html"
  },
  "original_language": "en",
  "account": "A novel technique, combining Mössbauer spectroscopy and visible-adjacent light, has enabled physicists to study the behavior of thorium-229 atoms within crystal structures. For years, scientists have utilized Mössbauer spectroscopy to analyze the atomic nuclei of solid materials, learning about the local environment surrounding each nucleus by observing shifts in their energy levels. However, the technique has primarily been used to study gamma rays, which have limitations in terms of precision and sensitivity to external fields.\n\nIn a groundbreaking study published in Science, a team led by Takahiro Hiraki at Okayama University demonstrated that thorium-229 could be examined using ultraviolet light instead of gamma rays. By doping thorium-229 into calcium fluoride crystals and probing them with a narrow, tunable vacuum ultraviolet laser, the researchers revealed that thorium ions could settle into four distinct positions within the crystal lattice. Each position left a unique fingerprint in the surrounding electric field, which could be exploited to selectively excite the thorium nuclei.\n\nThis discovery opens up exciting possibilities for the development of nuclear clocks, which could potentially achieve a level of precision far surpassing current atomic clocks. Nuclear clocks operate by tracking transitions deep within the nucleus, making them less susceptible to stray electric and magnetic fields. The gamma-ray lasers required to trigger these transitions have not yet been developed, with the notable exception of thorium-229, whose nuclear transition is at an energy level accessible with an ultraviolet laser.\n\nBy combining Mössbauer spectroscopy with laser excitation, Hiraki's team effectively produced a map of the most suitable crystal environments for hosting thorium-229 nuclei. This map identifies which sites will produce minimal timing errors and which should be avoided. In conclusion, this research represents a significant step forward in the quest to develop compact, ultra-precise nuclear clocks, potentially leading to a new era of timekeeping technology.",
  "summary": "For decades, physicists have used a technique called Mössbauer spectroscopy to peer inside solid materials, revealing fine details of their surroundings by studying how their atomic nuclei absorb and re-emit gamma rays.",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}