Semiempirical method of slow neutron flux calculation for neutron gauging

The distribution of slow neutrons in a hydrogen containing medium, as a basis of neutron moisture gauging, is investigated in the present work by introducing the effective moisture content. The value of the deviation of the effective moisture content from the true value of moisture content shows the contribution of the dry bulk density to the neutron distribution in the medium. This concept enables one to explicitly express the space neutron distribution as a function of the effective moisture content. The epithermal and thermal neutron fluxes in the medium under consideration were expressed in terms of the epithermal and thermal neutron fluxes in pure water. These latter fluxes need to be measured. Necessary corrections were calculated in the present work on the basis of P-1 approximation, diffusion and age theories. (orig.)