Elemental analysis of concrete via fast neutron transmission and scattering spectrometry

Abstract

We report on the development of neutron-based techniques to non-destructively measure the composition of concrete. Previous experimental studies demonstrated the viability of the unfolding technique to determine the ratio of water, sand and cement in well-characterised concrete samples from the transmitted neutron energy spectrum. In this work, we used MCNP6 simulations to demonstrate the extension of the technique to determine elemental compositions from transmitted, or scattered neutron energy spectra. In both cases, the simulated energy spectra provided a reliable method to unfold the composition of samples with known elemental ratios. The precision of the technique was limited by the statistical uncertainties of the simulated spectra, particularly for the case of scattered neutrons. The accuracy of the technique was heavily dependent on the uniqueness of each of the elemental responses, and reasonable prior knowledge of the composition. Given the promising results at this stage, future developments will include the addition of further elements to the response matrix, and experimental verification.