Measured Characteristics of Pulsed-Neutron Assaying of Uranium Ore Deposits

We are implementing a neutron-activation borehole-logging system to assay uranium ore in-situ for use in exploration and mine development. The method is based on detecting delayed neutrons from the uranium fission induced by cyclic activation from a pulsed, 14-MeV, neutron generator. The delayed neutron count rate is a measure of ore grade. Experiments in the laboratory and in the field have served to clarify characteristics of this delayed fission neutron (DFN) assaying process, in particular (i) its sensitivity to uranium ore grade and (ii) its susceptibility to sources of systematic error.