Monte-Carlo simulation of neutron transmission through nanocomposite materials for neutron-optics applications

TL;DR

This paper uses Monte-Carlo simulations to evaluate neutron transmission through nanocomposites, suggesting that isotopic substitution can significantly reduce neutron absorption and scattering losses for neutron-optics applications.

Contribution

It introduces a simulation approach to predict neutron transmissivity in nanocomposites with different isotopic compositions, guiding material optimization.

Findings

Deuterated and fluorinated nanocomposites can reduce losses to about 2%.

Simulation results align with experimental data.

Isotopic substitution improves neutron transmission.

Abstract

Nanocomposites enable us to tune parameters that are crucial for use of such materials for neutron-optics applications such as diffraction gratings by careful choice of properties such as species (isotope) and concentration of contained nanoparticles. Nanocomposites for neutron optics have so far successfully been deployed in protonated form, containing high amounts of $^1$H atoms, which exhibit rather strong neutron absorption and incoherent scattering. At a future stage of development, chemicals containing $^1$H could be replaced by components with more favourable isotopes, such as $^2$H or $^{19}$F. In this note, we present results of Monte-Carlo simulations of the transmissivity of various nanocomposite materials for thermal and very-cold neutron spectra. The results are compared to experimental transmission data. Our simulation results for deuterated and fluorinated nanocomposite materials predict a decrease of absorption- and scattering-losses down to about 2 % for very-cold neutrons.