Neutron tomography: Insights into the interior of teeth, root balls, batteries, and fuel cells
Fossils like this 250 million year old skull of a lystrosaurus can be examined very carefully by neutron tomography. © MfN Berlin
Neutron tomography shows how torsion (images left) and tensile forces (image right) are changing the distribution of different crystalline phases. © HZB/Wiley VCH
Sequential tomography of a lupin root (yellowish green) after deuterated water (D2O) was introduced from below. The rising water front (H2O, dark blue) is displaced by the D2O from below over the course of time. ©Christian Tötzke/ University of Potsdam
A team of researchers at Helmholtz-Zentrum Berlin (HZB) and European Spallation Source (ESS) has now published a comprehensive overview of neutron-based imaging processes in the renowned journal Materials Today (impact factor 21.6). The authors report on the latest developments in neutron tomography, illustrating the possible applications using examples of this non-destructive method. Neutron tomography has facilitated breakthroughs in so diverse areas such as art history, battery research, dentistry, energy materials, industrial research, magnetism, palaeobiology and plant physiology.
Neutrons can penetrate deep into a sample without destroying it. In addition, neutrons can also distinguish between light elements such as hydrogen, lithium and substances containing hydrogen. Because neutrons themselves have a magnetic moment, they react to the smallest magnetic characteristics inside the material. This makes them a versatile and powerful tool for materials research. 2D or 3D images, called neutron tomographs, can be calculated from the absorption of the neutrons in the sample. A world-renowned team headed by Dr. Nikolay Kardjilov and Dr. Ingo Manke is working with BER II, the neutron source at HZB, to constantly expand and improve of neutron tomography methods.
In their review paper, the authors describe the latest improvements in neutron imaging and present outstanding applications. Improvements in recent years have extended the spatial resolution down into the micrometer range. This is more than ten times better than with typical medical x-ray tomography. Faster images are also possible now, which makes observing processes in materials feasible, such as the “in operando” measurements of a fuel cell during its actual operation that shows precisely how the water is distributed in it. This provides important information for optimising the design of the cell.
Applications range from observing the transport of lithium ions in batteries and strength analyses of industrial components, to examinations of teeth, bones, and the roots of plants, to non-destructive analyses of historical objects such as old swords and knights' armour in order to obtain information on historical manufacturing methods.
“Neutron tomography is extremely versatile. We are working on further improvements and hope that this method, which is in great demand, will also be available in modern spallation sources in the future”, says Nikolay Kardjilov.
Publication: Materials Today 2018; “Advances in neutron imaging”, Nikolay Kardjilov, Ingo Manke, Robin Woracek, André Hilger, John Banhart
DOI: 10.1016/j.mattod.2018.03.001
- Magnon momentum microscopy: A new window into nanoscale spin-wavesAn international team lead by the Max Born Institute has developed a new type of momentum microscopy to image magnons — the quanta of collectively excited spins — directly in two-dimensional reciprocal space using soft X-rays. Measurements have taken place at BESSY II and PETRA III, first author ist the HZB physicist Steffen Wittrock. Owing to its remarkable sensitivity, simplicity, and access to nanometer-scale wavelengths, this novel technique establishes a powerful and versatile platform for exploring nonlinear magnon interactions, which are promising for future computing schemes.
- X-ray analysis reveals overpainted fascist symbolsErich Mercker was a successful painter during the Nazi era and in the years that followed. After 1945, he covered up Nazi symbols in at least one of his paintings. With an interdisciplinary team, physicist Dr Ioanna Mantouvalou reports on this study in the Nature Journal Heritage Science.
- AI agents deliver results – but do they reason scientifically?A research team co-led by Kevin Maik Jablonka from the Helmholtz Institute for Polymers in Energy Applications Jena (HIPOLE Jena) and N. M. Anoop Krishnan from the Indian Institute of Technology Delhi has developed Corral, a new benchmark for AI agents in science. The preprint “AI scientists produce results without reasoning scientifically” has been published on arXiv (https://doi.org/10.48550/arXiv.2604.18805). The analysis shows that current systems can execute scientific workflows and deliver results; however, they often do not follow the basic principles of scientific testing and reasoning.