Calculation of Neutron Ages and Slowing Down Spectra in Light Water for a Fission Source and a D-T Source

摘要

Numerical calculations on neutron age and neutron spectra for a fission source and a D-T source in light water have been performed by means of a stochastic method of calculation for the slowing down process. The formulas for calculation have been derived through direct operational treatment. In dealing with neutron degradation, account has been taken of both inelastic scattering and anisotropy of elastic scattering in the center of mass system (c.m.s.). To elucidate the effects brought by these factors, and to compare the present exact results with those by G.G. approximation for isotropic scattering, numerical calculations have been performed and discussions on the results are given. The results obtained on neutron age are in good agree-ment with values from experiment by other authors. The neutron ages from a fission source and a D-T source to In resonance have been found to be 26.34 and 156.4 cm2, respectively.