Microabsorption of X-rays in Planar Powder Samples in the Non-Symmetric Reflection Case

The microabsorption of X-rays in planar samples of heterogeneous materials and multiphase powder specimens with rough surfaces is theoretically studied for the experimental situation of non-symmetric beam geometry. Analytical expressions are derived which describe the microabsorption effect and its dependence on incidence and scattering angle, surface roughness, bulk porosity and absorption contrast. Experimental data are presented which confirm the theoretical results.