New data for the analysis of critical raw materials

Dr. Eric Mauerhofer from Forschungszentrum Jülich and his colleagues at RWTH Aachen University and the University of Cologne have published new findings on the gamma emissions of nickel, zirconium, lanthanum, and praseodymium. These elements are indispensable materials for sustainable energy systems and high-tech industries. Using the FaNGaS (Fast Neutron-induced Gamma-ray Spectrometry) instrument from Jülich Centre for Neutron Science at MLZ, their study provides valuable insights into these critical raw materials, supporting their effective application in advanced technologies.

The researchers investigated rare earth metals. © Adobe Stock / Reiner Müller, FRM II / TUM

The researchers investigated rare earth metals. © Adobe Stock / Reiner Müller, FRM II / TUM

Materials for batteries, wind turbines, and reactor technology

The researchers examined nickel, zirconium, lanthanum, and praseodymium using the FaNGaS spectrometer. Nickel and lanthanum are used in batteries for electric and hybrid vehicles, which play a significant role in advancing electromobility—a key technology in combating climate change. Zirconium is primarily valued in the nuclear energy sector for its use in fuel cladding, as it is significantly more radiation-resistant than the stainless steel alloys previously employed. This enhances the safety and efficiency of modern reactors. Praseodymium is crucial in the production of powerful magnets used in wind turbines, enabling efficient energy conversion.

Critical raw materials

Lanthanum and praseodymium are classified as “critical” by the European Commission due to their limited availability and high demand.
This makes it even more important to develop sustainable methods for precise compositional analysis of the raw materials, ensuring that both the primary constituents and any impurities or foreign elements—which might compromise the material’s performance or safety—are accurately identified.

Magnet sample fabricated by Fraunhofer Research Institution for Materials Recycling and Resource Strategies IWKS analysed at the FaNGaS instrument. © Simon Habold, FRM II / TUM

Magnet sample fabricated by Fraunhofer Research Institution for Materials Recycling and Resource Strategies IWKS analysed at the FaNGaS instrument. © Simon Habold, FRM II / TUM

Neutrons for examining large samples

Dr. Eric Mauerhofer and Dr. Iaroslav Meleshenkovskii from Forschungszentrum Jülich, along with Dr. Christian Stieghorst and Dr. Zsolt Révay from FRM II, utilised the FaNGaS instrument at MLZ to determine the partial differential cross sections of gamma rays emitted from the inelastic scattering of fission neutrons. These measurements not only demonstrate that FaNGaS is a unique instrument for obtaining crucial nuclear data and for the non-destructive analysis of thick and dense samples, but they also contribute to the update of the (n,n′,γ) reactions data catalogue, enriching our understanding of nuclear interactions. “Notably, MLZ is one of the few facilities in the EU capable of providing a fission neutron beam—thanks to a special converter installed at FRM II”, says Melenshenkovskii.

The FaNGaS spectrometer at experimental position (left picture).The rear part of the shielding with its opening doors made of borated polyethylene (upper right picture) to access to the detector after removing of some lead bricks (down-right picture) © Dr. Iaroslav Meleshenkovskii, JCNS

The FaNGaS spectrometer at experimental position (left picture).The rear part of the shielding with its opening doors made of borated polyethylene (upper right picture) to access to the detector after removing of some lead bricks (down-right picture) © Dr. Iaroslav Meleshenkovskii, JCNS

The derived data were obtained using an advanced fast neutron based analytical technology—PGAINS (Prompt Gamma Analysis based on Inelastic Neutron Scattering). The PGAINS method, which leverages high-energy fission neutrons, offers several advantages: the ability to analyze thicker and denser samples, improved sensitivity to some elements, reduced activation, and rapid analysis. This approach facilitates the sustainable handling and recycling of such critical raw materials in the context of a circular economy.

“This method allows for the non-destructive analysis of larger and thicker samples compared to established techniques based on cold or thermal neutrons,” explained Meleshenkovskii. “We now have a promising tool to analyze challenging samples that are several centimetres thick and dense. These samples can come from fields such as archaeology, geology, industry, and fundamental research.”