A neutron detector includes a coincidence detector to detect coincidence events in which each coincidence event indicates proximity in time of a first signal and a second signal. The first signal indicates detection of at least one of a neutron or a gamma ray, and the second signal indicates detection of a gamma ray by a gamma ray detector. A data processor identifies detection of neutron radiation based on characteristics of an energy spectrum of the gamma rays associated with the second signals that correspond to the coincidence signals.