Neutron detector

A neutron detector is provided which is able to measure thermal neutron radiation within a gap filled with a substance that permits scintillation in the absorption of thermal neutron radiation, the gap being formed between at least a first and second spaced apart photodetector working in electrical coincidence. The substance disposed within the gap can be either a gas, liquid or solid. In the case of a gas, a shell is used so that the gas can be retained and kept under pressure. The neutron detector is able to differentiate between gamma radiation and neutron energy. An alternate embodiment of the novel detector includes a device which employs a plurality of detectors surrounding a moderator which can be used to measure both thermal and high energy neutrons.