Small-angle multiple scattering is considered in the case when the single scattering is a refraction on an inhomogeneity. A system of spherical particles or pores with radii R randomly distributed over the sample volume V is studied in the diluted case when V much-greater-than deltaV, where deltaV is the volume occupied by the particles (pores). It is shown that there are two regions of the sample thickness L. In the first one the multiple scattering is a result of slightly modified random walks when the characteristic transferred momentum is proportional to [(L/l)ln(L/l)]1/2, where l is the mean free path. For large L (the second region) the characteristic momentum transfer is equal to (L/2lR). For lower q the intensity is q independent and for large q it is determined by single scattering and decreases as q-3.
