Steady neutron source measurement method for Sigma(a) and Sigma(s) in geological samples

An improved experimental method, using a steady neutron source in a moderat ing medium, has been developed to determine thermal neutron absorption and scattering cross sections for bulk geological media using discrete samples. The system design has been optimized and experimental results have been be nchmarked using Monte Carlo simulation. Studies have been performed to impr ove the measurement sensitivity and reproducibility over previous designs. A semi-empirical model has been developed for determining both absorption a nd scattering cross sections of the sample. (C) 2000 Elsevier Science Ltd. All rights reserved.