The world of scientific imaging is about to get a whole lot sharper, thanks to a groundbreaking development in neutron lens technology. This new lens, the first of its kind, has the potential to revolutionize our understanding of materials by bringing neutrons into sharp focus, opening up a whole new realm of possibilities for imaging and analysis.
Neutrons, as you may know, are incredibly useful for getting unique insights into the structure of materials. They can penetrate deep into metals and are highly sensitive to light elements like hydrogen and lithium. This makes them perfect for observing oil, polymer, or lithium distribution inside dense metallic structures, revealing water uptake in plants, or even examining priceless archaeological artifacts without causing any damage.
However, neutrons have a weakness: they interact very weakly with matter, making it difficult to deflect or focus them. This has been a major barrier to developing advanced imaging techniques, as neutron beams typically contain neutrons of many different wavelengths, making it challenging to achieve high-resolution images.
Until now, that is. A team of scientists at the Paul Scherrer Institute (PSI) has developed a new type of lens that overcomes this challenge. This achromatic neutron lens focuses a broad range of neutron wavelengths to the same point, enabling sharp, magnified imaging with a resolution below twenty micrometers, even for objects that cannot be placed close to the detector.
This development is a significant breakthrough, as it opens up a whole new way of acquiring images. It allows researchers to follow processes inside equipment like furnaces, cryostats, or pressure cells, and it paves the way for neutron microscopy, which can produce magnified images of objects and reveal even more detail.
The new lens is a result of a collaboration between experts in neutron imaging, X-ray optics, and nanofabrication, all based within walking distance of each other on the PSI campus. The lens consists of concentric rings made of nickel and precisely shaped diamond structures, arranged in a carefully defined geometry. Unlike conventional visible-light lenses, which rely only on refraction, the neutron lenses also exploit diffraction, a phenomenon that causes waves to spread out or form patterns when passing through gratings or small apertures.
The intricate nickel structures were fabricated using electron-beam lithography in PSI's recently inaugurated PICO cleanroom facilities, while the diamond refractive structures were manufactured by the Swiss company SYNOVA S.A. The nickel rings get smaller and smaller, with the finest rings measuring well below 200 nanometres.
The team tested the lens by imaging a commercial lithium-ion battery, placed six meters away from the detector. They were able to magnify the layered structure of the wound electrode assembly by seven times, opening up the possibility of observing fine internal details of materials and devices while they are functioning in realistic environments.
This is just the beginning, according to the researchers. They already see ways to improve the lens, and the key point is not just resolution but a completely new way of acquiring images. Neutron imaging facilities will now have to catch up, and some may need longer beamlines to fully exploit the new lenses.
The development of the neutron lens builds on the team's earlier breakthrough in X-ray optics, which was developed in 2022. This achievement demonstrates the power of collaboration and the potential for technological breakthroughs when experts from different fields work together.
In conclusion, the development of the first-ever neutron lens is a significant milestone in scientific imaging. It opens up a world of new possibilities for understanding materials and devices, and it is a testament to the power of collaboration and innovation in scientific research.
