BNC webinar #5 on Renewable Energy "The Neutron Depth Profiling Instrument N4DP at the PGAA facility of the Heinz Maier-Leibnitz Zentrum"               by            Markus Trunk (Department of Physics Technical University Munich, Germany)          Introduction               on            19 May, 2021     14:00 - 14:45 + discussion    For the request of the speaker no video was recorded

Abstract: Neutron Depth Profiling (NDP) is a non-destructive, isotope-specific, nuclear analytical technique, which is especially sensitive to light nuclides like He-3, Li-6 and B-10. Upon neutron  capture, the investigated nuclei decay into two charged particles with well-defined energies. Before the charged particles are detected, they lose energy while traveling through the host material  before they emanate from the sample surface. Their remaining energy is related to the depth of their production, i.e. the location of the mother nuclei, and so a concentration profile is obtained.
The strong energy loss entails depth sensitivities up to a few ten nanometers while limiting the maximum penetration depth to tens of micrometers. The PGAA facility of the Heinz Maier-Leibnitz Zentrum provides a collimated cold neutron flux with a high thermal equivalent flux density of 2·10⁹ s^-1cm^-2 and a low signal-to-noise ratio and so concentration profiles can be obtained with high time resolutions. The high time resolution combined with the non-destructive nature of the measurement are of special interest for lithium-ion batteries, where the lithium transport processes can be studied during operation. However, due to the limited viewing depth a special battery cell design is required, which is transparent for the charged particles while ensuring an undisturbed battery performance even at low ambient pressures. Here the N4DP instrument at the PGAA facility is introduced and NDP measurements on materials science applications are presented focusing on lithium-ion battery applications. Measurements of operando NDP on lithium-ion batteries using a newly developed cell design are presented.

BNC webinar #4 on Renewable Energy "Neutron Imaging in Energy Research"               by            Nikolay Kardjilov (Helmholtz-Zentrum Berlin, Germany)               on            20 January, 2021     14:00 - 14:45 + discussion           Lecture video

Abstract: Imaging techniques based on neutron beams are rapidly developing and have become versatile non-destructive analysing tools in many research fields. Due to their intrinsic properties, neutrons differ strongly from electrons, protons or X-rays in terms of their interaction with matter: they penetrate deeply into most common metallic materials while they have a high sensitivity to light elements such as hydrogen, hydrogenous substances or lithium. This makes neutrons perfectly suited probes for research on materials that are used for energy storage and conversion, e.g. batteries, hydrogen storage, fuel cells, etc.