Abstract: The simultaneous selective detection of neutrons and X or gamma photons is disclosed, employing two scintillators. One scintillator uses a first doped scintillation detector that is sensitive to neutrons, while the second doped scintillation device is sensitive to X or gamma photons whereby the scintillations occurring at the two devices are in distinct and separate energy bands.

Abstract: An apparatus for the simultaneous, selective detection of neutrons and X or gamma photons including a photomultiplier, a first scintillator sensitive to the neutrons and a second scintillator sensitive to the x or gamma photons. The apparatus also includes an attenuating light guide (situated between the first and second scintillators) for guiding the photons produced by the first scintillator to the photomultiplier and for attenuating the radiation associated with these photons. The attenuating light guide facilitates the separation of the energy bands associated with each of the first scintillator, the second scintillator and the background noise of the photomultiplier. By separating energy bands, detection of each radiation element is less complex. The apparatus also includes a neutron filter (situated between the attenuating light guide and the second scintillator) which functions to reduce the occurrence of neutrons interacting with the second scintillator, thus facilitating energy band separation.