Methods for determining a part of neutron energy dissipated in the processes of elastic atom collisions

Experiment block-diagram and methods of determining ratio of neutron energy dissipated during elastic atomic collision in silicon, are described. A semiconducting detector (SCD), operating in the current regime, as well as calorimeter, the absorber of which is made of the same material, as SCD, are placed in the gamma-neutron field of radiation in the process of the experiment. Measurements have been carried out in the beam of the horizontal channel of IRI-200 reactor. Lead and bismuth filtres have been used for gamma-radiation background reduction. Enriched lithium-6 has been used for protection from thermal neutrons. Diffusion-drift detector has been applied as a semiconducting detector (SCD). Calculation results of dose relation of atomic collisions in carbon, silicon and germanium to neutron dose rate in polyethylene are presented. The calculation is executed on the Lindhard theory base with account of nonisotropy of neutron scattering and contribution of neutron inelastic scattering for six neutron spectra measured by a set of activation detectors in the IRI-200 reactor channels, differing by their characteristics (horizontal channel without filter and with graphite and lead filtres and several vertical channels). It is noted, that the considered measuring method is applicable in the fields with the density of fast neutron flux up to 1010 neutron/cm2 and slight background of gamma-radiation. Based on comparing the obtained data a conclusion is made on reliability of determining the dose of elastic atomic collisions by neutron dose rate in water-containing matter