Non-destructive characterization of magnets with fast neutrons

Topic  5
Main supervisor E.Mauerhofer (
MLZ institution FZJ
Local supervisor 1 E.Wooldridge
Institution Dynaxion
Local supervisor 2 S.Tiedke
Institution AixACCT System GmbH
Local supervisor 3 E.Brouwer
Institution Fraunhofer Inst Hanau
Local supervisor 4
Title Non-destructive characterization of magnets with fast neutrons
Description Rare earth magnets and in particularly NdFeB magnets are a critical component of modern technology and their recycling is of strategic importance for Europa. An efficient recycling requires in front end a sorting of the magnets according not only to their type (Ferrite, SmCo, AlNiCo, NFeB, etc.) but also to their rare earth elements content. The chemical composition of magnets is generally determined by destructive analytical methods such as ICP-MS or -OES (Induced Coupled Plasma-Mass/Optical Emission Spectrometry) providing very accurate results but necessitating dissolution of a part of the sample. In the case of heterogeneous samples the results are not representative for the whole sample.   XRF (X-Ray Fluorescence) and LIPS (Laser Induced Plasma Spectrometry) are also used as non-destructive methods but they provide only near-surface information and are not able to identify stacks of materials. A precise and accurate non-destructive bulk analysis of magnet samples of various composition, geometry and thickness can be achieved using fast neutrons and measuring the element specific prompt gamma rays induced by the inelastic scattering of fast neutrons, (n,n´gamma)-reaction. The analysis of magnets can be performed with the instrument FaNGaS (Fast Neutron induced Gamma Spectrometry) installed at the Heinz Maier-Leibnitz Zentrum (MLZ). However, the industrial recycling of magnets requires a characterization of magnets necessitating an operation of the neutron based analytical technique on-site. The aim of this project is to develop a fast-neutron analytical system with a compact accelerator based neutron source and a high resolution spectrometer for non-destructive characterization of magnets. The design and optimization of the system will be performed by numerical simulations using MNCP or FLUKA codes and supported by measurements of various samples with FaNGaS at MLZ for validation.