Interparticle interference of neutrons in multiple small-angle scattering by a close-packed polydisperse system

Small-angle multiple neutron scattering by a disordered polydisperse system with various concentrations of scattering centers is studied experimentally and theoretically. The experiments show that, for high concentrations (specific volume of scatterers $\geq 30$%), interparticle interference of neutron waves plays a significant role and strongly affects the angular distribution of scattered neutrons. The experimental results are qualitatively explained within the framework of the theory allowing for pair correlations in the spatial distribution of scatterers.