Energy broadening of neutron depth profiles by thin polyamide films

A protective covering is often required for neutron depth profiling (NDP) measurements of sensitive materials (e.g., Li-ion batteries). Addition of this layer can increase NDP profile energy broadening and depth assignment uncertainty. This study evaluates the magnitude of these effects when polyimide films of variable thicknesses are placed over Li-rich solids. Key results include a modeled increase in cold neutron beam attenuation with increased film thickness, a methodology for estimating profile energy broadening using a sigmoidal function, and, when using a thick layer, that the broadening will add uncertainity to the zero-depth position and depth scale assignment. (author)