Physicists at TU Wien have developed a nuclear clock that measures time using oscillations of thorium atomic nuclei. The device can autonomously maintain its timekeeping accuracy without external standards, opening the way to an era of ultra-precise time, infohub.kz reports.
Today's ultra-precise timekeeping relies on optical atomic clocks, which are based on electron transitions. However, electrons in outer orbits are sensitive to temperature changes and external fields. At TU Wien, researchers turned to thorium nuclei for the task — they are thousands of times better shielded from external interference.
The system is built around a thorium crystal and a control laser. When the laser beam begins to drift from the required frequency, the thorium nuclei absorb less light. The automation instantly detects this shift and returns the laser to the correct rhythm. In the first tests, the setup ran successfully without failure for more than 24 hours.
For now, the prototype's error is about one second over 30 million years. That figure does not surpass the results of the best existing optical clocks, but physicists are confident that refining the crystal and the laser will allow nuclear clocks to outpace all current time-measurement technologies.