Hyperfine interactions and nuclear radiations

The paper deals with physics of hyperfine interactions, i.e., interactions of atomic nuclei with electromagnetic fields generated by electrons surrounding the nucleus. Primary attention is paid to nuclear methods of study on hyperfine interactions (Moessbauer effect, perturbed angular distributions and correlations, the method of nuclear orientation). Problems of physics of hyperfine interactions in artificial atoms (mesoatoms, muonium) are presented in brief. The material deals with problems of nuclear physics, solid physics, as well as with applied studies where these methods are used