Phenomenological and microscopical description of scattering on different dislocation arrangements

Two approaches are used to analyse X-ray or neutron scattering by crystals with different dislocation ensembles. Analogy between the above concepts is discussed. The microscopical approach takes into account the detailed disp lacement field due to different types of dislocation arrangement in the cry stal. Frequently a phenomenological concept operating with the ideas of dis placements, strains and stresses arising in the materials under deformation is applied. Unfortunately, the phenomenological concept cannot take into a ccount that similar stress distributions may have significantly different m icroscopic reasons. The comparison of the results obtained by both phenomen ological and microscopic descriptions of scattering enables us to understan d the connection between different types of strains and stresses in the cry stal with the type of the defects in it.