Home
Tech
This record-breaking ultraviolet crystal can unlock nuclear clocks and change the way submarines, spacecraft and missiles navigate without external signals.

This record-breaking ultraviolet crystal can unlock nuclear clocks and change the way submarines, spacecraft and missiles navigate without external signals.

Nuclear clocks promise much greater precision than existing atomic timing systems
Thorium-229 Offers Rare Path to Practical Nuclear Time Measurement
Ultraviolet breakthrough reduces one of the most difficult barriers in the development of a nuclear clock

A new crystal developed by Chinese scientists has broken the world record for ultraviolet light conversion, bringing nuclear clock technology closer to reality.

The fluorinated borate compound pushes the laser light to a wavelength of 145.2 nm, surpassing the previous benchmark of 150 nm set by a Chinese crystal from the 1990s.

This wavelength is short enough to meet a key requirement for ultra-precise wearable nuclear clocks being developed in the United States, China and other countries.

Article continues below.

Nuclear clocks: a major GPS upgrade

Nuclear clocks keep time using vibrations within an atomic nucleus rather than electron vibrations used in atomic clocks.

Atomic nuclei are much more stable than electrons and are less affected by temperature, external vibrations and magnetic fields, meaning that nuclear clocks could be 10 to 1,000 times more accurate than current atomic clocks.

Such precision would allow navigation in places where GPS does not work, including deep space and underwater.

Currently, submarines need to surface to locate GPS, making them vulnerable to detection, so a nuclear clock could allow them to navigate freely underwater using dead reckoning based on speed, direction and elapsed time.

The research team, led by Pan Shilie at the Xinjiang Technical Institute of Physics and Chemistry, turned to thorium 229 for their work.

This element is special because its core vibrates at a very low energy level, making it relatively easy to monitor and measure.

However, measuring it requires extremely precise UV lasers with wavelengths around 148.3 nm, which have been very difficult to produce.

The new glass converts laser light to 145.2 nm, still below target, but a big step forward.

The team wrote that their work “paves the way for the practical development of the thorium-229 nuclear clock.”

If the magic number is ever achieved, the crystal could also help missiles become immune to navigational jamming, an advantage in wartime.

For spacecraft, autonomous deep space navigation without Earth-based corrections would be possible, and signals from stars, pulsars and radio sources could also serve as navigation aids.

The work also offers a new way to design next-generation deep ultraviolet materials for various applications.

In theory, the extreme precision of nuclear clocks could allow for much tighter network synchronization, which could lead to faster Internet speeds in future systems.

However, these clocks probably won't make GPS completely redundant, but they will help reduce dependence on these systems if they are perfected.

GPS can be jammed or spoofed with false signals, making it vulnerable in times of war, and does not work well underwater or underground. A thorium nuclear clock would address all of these limitations.