Measurements of Spatially Independent Reactivity in Pulsed-Neutron Experiments

Through the measurement of the kinetic distortion effect, defined as the modal shape and spectral difference between the fundamental prompt- and delayed-neutron modes, a spatial correction factor for the reactivity of the system, as determined by the Gozani and Garelis-Russell modified pulsed-source methods, is obtained. This factor is the ratio of the experimentally determined and properly normalized delayed- and prompt-neutron densities measured in a pulsed-neutron experiment. With this spatial correction factor the reactivity of the system is obtained as a true global parameter. The results of measurements in several ²³⁵U enriched-uranium cores reflected by light water and by graphite and light water are presented.