THE TOTAL GAMMA-RAY ENERGY SPECTRUM ABOVE 1 MeV FROM NEUTRON INTERACTIONS IN 23SU AND 238U

摘要

The total gamma-ray energy spectra above 1 MeV from neutron interactions in 235U and 238U were measured to test the accuracy of model calculations and to improve the accuracy of shielding calculations by reducing the uncertainty in the source term.nThe general structure of the gamma-ray energy spectrum above 1 MeV from fission was independent of the isotope where the fission occurred and the energy of the neutron that caused the fission. This total fission spectrum was approximated to an accuracy of 20% by a simple empirical expression which, between 1 and 5.12 MeV, is twice the spectrum from prompt fission.nThe gamma-ray energy spectrum from all neutron interactions in 23SU was dominated by the total fission spectrum. The photon spectrum obtained as a result of reactor neutrons striking 235U had the same shape as the photon spectrum obtained from the same neutron beam filtered with cadmium.