Abstract: A neutron detector circuit for a neutron detector is disclosed that includes a scintillator having a plurality of wavelength shifting optical fibers. A first detection circuit is connected with a first PMT output that is configured to generate a first detection circuit output in response to a first neutron event. A second detection circuit is connected with a second PMT output that is configured to generate a second detection circuit output in response to a second neutron event. A coincidence detection circuit is included that has inputs connected with the first and second detection circuit outputs that is configured to generate a neutron event count output pulse in response to coincident signals being received by the coincidence detection circuit from the first and second detection circuit outputs.

Abstract: A neutron detection system includes a neutron scintillator having a thickness greater than an optimal thickness and less than twice the optimal thickness. The system includes a first layer of wavelength shifting fiber optic elements positioned on a first side of the neutron scintillator. Adjacent fibers of the first layer pass light to distinct photo-multiplication devices. The system further includes a second layer of wavelength shifting fiber optic elements positioned on a second side of the neutron scintillator. Adjacent fibers of the second layer pass light to distinct photo-multiplication devices. The two layers may share photo-multiplication devices or use different sets of photo-multiplication devices. The system includes a controller that distinguishes a neutron radiation event from a gamma radiation event in response to electronic signals from the distinct photo-multiplication devices.

Abstract: A method, device and retrofitting kit is disclosed that will protect materials that are housed within a storage device from one or more forms of radiographic imaging. A target subject is at least partially covered with a first and second layer of radiographic cloaking material. The first layer of radiographic cloaking material is configured to defeat a first type of radiographic beam, such as a photon beam. The second layer of radiographic cloaking material is configured to defeat a second type of radiographic beam, such as a particle beam.