The effect of the radiation capture of electrons (RCE) by a solid body, non-filled electron states (NES) in a solid body are considered in the paper aiming at the investigation of laws of RCE by a solid body in the range 0 - 6 eV of energies of electrons, the development of methodologies for the obtaining of the information about NES. As a result new laws of RCE by a solid body in the field of small energies of electrons have been determined as well as the excitation threshold of plasmons in silver, the model of the RCE effect by a solid body in energy range 0 - 6 eV. New methodical techniques for the obtaining of the information about NES of a solid body have been developedAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio