Correlation effects in small-angle multiple neutron scattering

The dependence of the spectra of small-angle multiple neutron scattering on the volume fraction occupied by scattering grains is considered. The conce ntration expansion is used to develop scattering theory in the eikonal appr oximation. The leading term of the expansion reproduces the standard low-co ncentration theory (Mollier). Some properties of the first correction term are analyzed, and it is shown that the angular distribution narrows with an increase in concentration, in qualitative agreement with the experimental data. (C) 2000 MAIK "Nauka/ Interperiodica".