Scientists have achieved a significant breakthrough in the quest to develop the world’s first practical nuclear clock. In a study published today in Nature, researchers unveiled a novel method for probing the thorium-229 nucleus, a development that could revolutionize timekeeping and have profound implications for fields such as navigation, communications, and even earthquake prediction.
The research team demonstrated a new technique that eliminates the need for specialized transparent crystals, which were previously essential for exciting the thorium-229 nucleus. This advancement not only simplifies the process but also significantly reduces costs, paving the way for real-world applications of nuclear clock technology.
The Science Behind the Breakthrough
Building on their landmark achievement from last year, where they used a laser to excite the thorium-229 nucleus inside a transparent crystal, the researchers have now succeeded in achieving the same results using a microscopic thin film of thorium oxide. This film was created by electroplating a minute amount of thorium onto a stainless-steel disc, a process akin to gold-plating jewelry.
Dr. Harry Morgan, co-author of the research and Lecturer in Computational and Theoretical Chemistry at The University of Manchester, explained the significance of this development.
“Previously, the transparent crystals needed to hold thorium-229 were technically demanding and costly to produce, which placed real limits on any practical application. This new approach is a major step forward for the future of nuclear clocks and leaves little doubt that such a device is feasible and potentially much closer than anyone expected.”
Implications for Timekeeping and Beyond
The new method employs conversion electron Mössbauer spectroscopy, a technique that has traditionally required high-energy gamma rays at specialized facilities. This study marks the first time it has been successfully demonstrated with a laser in a standard laboratory setting. By exciting the thorium nuclei with a laser, the energy is transferred to nearby electrons, which can then be measured as an electric current.
According to UCLA physicist Eric Hudson, who led the research, this discovery challenges previous assumptions about the materials needed for nuclear clocks.
“We had always assumed that in order to excite and then observe the nuclear transition, the thorium needed to be embedded in a material that was transparent to the light used to excite the nucleus. In this work, we realized that is simply not true,” Hudson said. “We can still force enough light into these opaque materials to excite nuclei near the surface and then, instead of emitting photons like they do in transparent materials like the crystals, they emit electrons which can be detected simply by monitoring an electrical current – which is just about the easiest thing you can do in the lab.”
Potential Applications and Future Research
Nuclear clocks, which rely on the natural “ticking” of single atoms, offer a level of precision that surpasses current atomic clocks. While atomic clocks depend on electron oscillations, nuclear clocks utilize the oscillations within the nucleus, making them less susceptible to external disturbances. This increased accuracy could have transformative effects on various technologies.
One of the most exciting potential applications is in the field of earthquake and volcano prediction. Due to Einstein’s theory of general relativity, nuclear clocks could detect small changes in Earth’s gravity caused by the movement of magma and rock deep underground. By deploying nuclear clocks in seismic zones, scientists could monitor tectonic activity in real-time and potentially predict natural disasters before they occur.
Dr. Morgan emphasized the long-term benefits of this technology:
“In the long term, this technology could revolutionize our ability to prepare for natural disasters. It’s incredibly exciting to think that thorium clocks can do things we previously thought were impossible, as well as improving everything we currently use atomic clocks for.”
Collaboration and Future Directions
This groundbreaking research was funded by the National Science Foundation and involved collaboration among physicists from the University of Nevada Reno, Los Alamos National Laboratory, Ziegler Analytics, Johannes Gutenberg-Universität at Mainz, and Ludwig-Maximilians-Universität München. The study, titled “Laser-based conversion electron Mössbauer spectroscopy of 229ThO2,” marks a significant step forward in the development of nuclear clock technology.
As scientists continue to explore the potential of thorium-229 and refine their methods, the dream of a practical nuclear clock moves ever closer to reality. This advancement not only opens up new avenues for scientific research but also holds the promise of transformative technological applications in the near future.
