PSI Combines X-Ray Optics and Neutron Science to Advance High-Resolution Neutron Imaging

Mano Raj Dhanalakshmi Veeraraj and Joan Vila-Comamala, both from the PSI Center for Photon Science, with the achromatic neutron lens outside the Swiss Spallation Neutron Source SINQ. Close collaboration between experts in neutron sciences and X-ray optics allowed a longstanding problem in neutron imaging to be overcome. © Paul Scherrer Institute PSI/Markus Fischer

(IN BRIEF) Researchers at the Paul Scherrer Institute PSI have developed the world’s first achromatic lens for neutron imaging, a breakthrough that allows neutrons of different wavelengths to be focused at the same point. The lens enables sharp, magnified images with resolution below 20 micrometres, even when samples are positioned far from the detector. The technology addresses a long-standing limitation in neutron imaging, where samples usually need to be placed close to the detector to maintain image sharpness. With the new lens, researchers can study thick samples and observe processes inside bulky equipment such as furnaces, cryostats and pressure cells. The PSI team tested the lens by imaging a commercial lithium-ion battery placed six metres from the detector, magnifying the layered electrode structure seven times. The breakthrough could support future neutron microscopy and enable researchers to observe internal changes in materials, batteries, engines and other devices under realistic operating conditions. The lens combines nickel diffraction structures and diamond refractive structures, drawing on PSI’s expertise in X-ray optics, neutron imaging and nanofabrication.

(PRESS RELEASE) VILLIGEN, 14-Jul-2026 — /EuropaWire/ — Researchers at the Paul Scherrer Institute PSI have developed the world’s first achromatic lens for neutron imaging, overcoming a long-standing technical challenge in the field and opening new possibilities for sharper, magnified views inside materials and equipment.

The breakthrough lens allows neutrons of different wavelengths to be focused at the same point, making it possible to produce clear images of samples that previously could not be positioned close enough to a detector for high-resolution imaging.

The development, reported in Nature Communications, could help researchers examine thick samples and observe processes inside bulky equipment such as furnaces, cryostats and pressure cells.

Neutron imaging offers distinctive advantages for studying materials. Like X-rays, neutrons can be used to look inside objects, but they interact with matter in a different way. Neutrons can penetrate deeply into many metals while remaining highly sensitive to light elements such as hydrogen and lithium.

This makes them valuable for studying oil, polymers or lithium inside dense metallic structures such as engines or batteries. They can also be used to observe water uptake in plants and to examine valuable archaeological artefacts without damaging them.

However, the same weak interaction with matter that makes neutrons useful also makes them difficult to deflect and focus. This has limited the development of advanced neutron imaging methods for decades.

A major challenge has been that neutron beams usually contain neutrons with many different wavelengths. For a sharp image, a lens must bring those wavelengths to the same focal point. Until now, no practical neutron imaging lens had been able to focus the broad range of wavelengths in a neutron beam.

Current neutron imaging is generally performed without lenses, which means samples must be placed close to the detector to keep images sharp. This limits both resolution and the size of the object or sample environment that can be studied.

“This limits the achievable resolution, as well as the size of the object or sample environment that can be imaged,” said Mano Raj Dhanalakshmi Veeraraj, first author of the study and PhD student in the PSI Center for Photon Science.

The new lens is an achromatic neutron lens, meaning it can focus a broad range of neutron wavelengths to the same point. It enables sharp, magnified imaging with resolution below 20 micrometres, even when objects cannot be placed close to the detector.

“The lack of such a lens has held back neutron imaging for decades,” said Joan Vila-Comamala, scientist at the PSI Center for Photon Science, who led the team. “Now that we have it, it becomes possible to follow processes inside equipment such as furnaces, cryostats or pressure cells. It also opens the path to neutron microscopy, making it possible to produce magnified images of an object and reveal more detail.”

In the study, the researchers tested the lens by imaging a commercial lithium-ion battery. With the battery positioned six metres from the detector, the team was able to magnify the layered structure of the wound electrode assembly seven times.

This capability could eventually allow scientists to monitor fine internal details of materials and devices while they operate in realistic environments, such as observing structural changes in components of a running engine.

“This is just the beginning,” said Dhanalakshmi Veeraraj. “We already see ways to improve the lens. The key point is not simply resolution, but a completely new way of acquiring images.”

The researchers note that neutron imaging facilities will need to adapt to take full advantage of the new lenses. Longer beamlines could allow greater magnification, meaning the future performance of the technique may depend partly on instrument design rather than the lens itself.

New facilities such as the European Spallation Source, currently under construction in Sweden, are already taking these needs into account, supporting future growth in neutron imaging and its applications.

The technology builds on PSI’s earlier work in X-ray optics. In 2022, the team developed an achromatic X-ray lens for use at synchrotron and X-ray free-electron laser facilities such as the Swiss Light Source SLS and SwissFEL.

The new neutron lens combines X-ray optics expertise from the PSI Center for Photon Science with neutron imaging expertise from the PSI Center for Neutron and Muon Sciences.

The lens is made from concentric nickel rings and precisely shaped diamond structures arranged in a carefully defined geometry. Unlike conventional visible-light lenses, which rely mainly on refraction, the neutron lens also uses diffraction.

The nickel rings generate the diffraction pattern, while the diamond structures refract the neutron beam. Together, these effects create a magnified image on the detector.

The intricate nickel structures were produced using electron-beam lithography in PSI’s 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,” said Vila-Comamala.

After fabrication, the prototypes were rapidly tested with X-rays at the Swiss Light Source SLS and with neutrons at the Swiss Spallation Neutron Source SINQ.

Dhanalakshmi Veeraraj said the achievement was made possible by the close proximity of neutron imaging, X-ray optics and nanofabrication expertise on the PSI campus.

“There are few other places in the world, if any, where this could have happened,” said Dhanalakshmi Veeraraj. “The close collaboration between experts in neutron imaging, X-ray optics, and nanofabrication, based within walking distance of one another on the PSI campus, makes technological breakthroughs such as this possible.”

[English]

Original Publication
Dhanalakshmi Veeraraj M raj, Qu D, Chen H-Y, Strebel S, Qi P, Fedrigo A, et al.
An achromatic neutron lens
Nature Communications. 2026.https://doi.org/10.1038/s41467-026-74925-w
DORA PSI   Original Publication

Media Contact:

Dr. Joan Vila Comamala
PSI Center for Photon Science
Paul Scherrer Institute PSI
+41 56 310 51 33
joan.vila-comamala@psi.ch

SOURCE: Paul Scherrer Institute