Internal magnetic field gradients as information source about porous media characteristics

The geometry of particles is analyzed by the example of a model porous system (filling of glass spheres and glass cylinders) studied by nuclear magnetic resonance. The experimental approach is based on the registration of the < G(int)>(xi) dependences, where < G(int)> is the effective (average) internal magnetic field gradient and xi = < r(2)>(1/2)/< R > is the ratio of the root-mean-square displacement of molecules to the average particle size < R >. It is shown that the dependence < Gint >(xi) can be approximated by the power law < G(int)>(xi) proportional to xi(alpha), where the power index alpha does not depend on the particle size but is sensitive to its geometry.