Abstract: 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.

Abstract: 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.

Abstract: An ionization chamber is provided for the detection of nuclear radiation. The chamber is a vessel which acts as a cathode wherein at least one anode is disposed within the chamber and off-set from a center axis of the chamber. The chamber can be made from variety of shapes but is cylindrical in the preferred embodiment. The device contains two anodes in the preferred embodiment which are both off-set from the center axis. One anode collects the free floating electrons which are produced in response to particle ionization and therefore has a collected charge applied thereto. The second anode has the charge induced by immobile ions. The induced charge is subtracted from the collected charge thereby providing an improved resolution for the ionization chamber which translates into a more accurate result. In the preferred embodiment, a pressurized noble gas, such as xenon, is used.

Abstract: A nuclear or x-ray detector which utilizes Compton double-scattering of photons by radiation particles, followed by photoelectron absorption, to reconstruct the energy and direction of such particles.