GAMMA-RAY SPECTRA ARISING FROM THERMAL-NEUTRON CAPTURE IN ELEMENTS FOUND IN SOILS, CONCRETES, AND STRUCTURAL MATERIALS

摘要

Gamma-ray spectra arising from the capture of thermal neutrems are presented for iron, aluminum, copper, zinc, titanium, nickel, silicon, calcium, potassium, sodium, barium, chlorine, sulfur, and stainless steel. The spectral intensities in photons per 100 captures are presented as both individual lines and as sums of these lines over 0.5-MeV intervals which are intended for use in shielding calculations. The latter results have an estimated accuracy of +15%, and include the contributions from both discrete and continuum gamma rays. Comparisons of these spectra are made with previously determined spectra, as well as with values reported in the Reactor Handbook, and considerable revision in the latter is concluded to be necessary. The present results do not go below 1 MeV, but when the relatively small contributions from energies less than 1 MeV are added to them, binding energy checks within +5% are obtained.