Abstract: A semiconductor material for radiation absorption and detection comprising a composition of stoichiometry Li(M12+, M22+, M32+, . . . )(G1V, G2V, G3V, . . . ) and exhibiting an antifluorite-type order, where Li=1, (M12++M22++M32++ . . . )=1, and (G1V+G2V+G3V+ . . . )=1. The material provides two useful characteristics: [1] a high Li-site density, which when enriched in 6Li, produces exceptional neutron-absorbing capabilities and [2] a semiconducting band-gap for the efficient conversion of absorbed photon and neutron energies into electrical currents. These characteristics can be exploited in applications for power generation or the spectroscopic detection of gamma and neutron radiation. The material can be tailored so as to detect only gamma photons, detect only neutron particles, or simultaneously detect gamma photons and neutron particles.

Abstract: A neutron scintillator composite (NSC) material is made of a neutron scintillator material and a binder material. The binder material has an index of refraction substantially identical to the neutron scintillator material. The neutron scintillator material and binder material are mixed into a solid or semi-solid neutron scintillator composite material with sufficient flowability for molding into a shaped article, such as a neutron sensing element of a radiation detector. The neutron scitillator composite material collects and channels photons through the material itself and into a photosensing element optically coupled to the material. Because the indices of refraction for both the neutron scintillator material and the binder material are substantially identical, scattering at the scintillator-binder interface(s) is minimized, thereby producing transmission efficiencies that approach single crystals.

Abstract: A neutron sensing material detector includes an anode; a cathode; and a semiconductor material disposed between the anode and the cathode. An electric field is applied between the anode and cathode. The semiconductor material is composed of a ternary composition of stoichiometry LiM2+GV and exhibits an antifluorite-type ordering, where the stoichiometric fractions are Li=1, M2+=1, and GV=1. Electron-hole pairs are created by absorption of radiation, and the electron-hole pairs are detected by the current they generate between the anode and the cathode. The anode may include an array of pixels to provide improved spatial and energy resolution over the face of the anode. The signal value for each pixel can be mapped to a color or grey scale normalized to all the other pixel signal values for a particular moment in time. A guard ring or guard grid may be provided to reduce leakage current.

Abstract: A neutron detection system comprising a radiation portal monitor is disclosed. The radiation portal monitor includes a neutron moderator sheet and a neutron-sensing panel and is configured to receive incoming neutrons through a neutron collection portal area. The neutron-sensing panel comprises a neutron-sensing material optically coupled to a plurality of optical fibers such that the neutron moderator sheet and the neutron-sensing panel are disposed substantially parallel to the neutron collection portal area.

Abstract: A radiation detector includes a neutron sensing element having a neutron scintillating material at least partially surrounded by an optical waveguide material; and a photosensing element optically coupled to the neutron sensing element. The photons emitted from the neutron sensing element are collected and channeled through the optical waveguide material and into the photosensing element.

Abstract: A method of making a cubic halide scintillator material includes pressing a powder mixture of cubic halide and at least one activator under conditions of pressure, temperature, residence time and particle size effective to provide a polycrystalline sintered cubic halide scintillator having a pulse height resolution of from about 7% to about 20%. The conditions include a temperature ranging from about ambient temperature up to about 90% of the melting point of the cubic halide, a pressure of from about 30,000 psi to about 200,000 psi, a pressing residence time of from about 5 minutes to about 120 minutes and an average cubic halide particle size of from about 60 micrometers to about 275 micrometers.

Abstract: A neutron sensing material detector includes an anode; a cathode; and a semiconductor material disposed between the anode and the cathode. An electric field is applied between the anode and cathode. The semiconductor material is composed of a ternary composition of stoichiometry LiM2+GV and exhibits an antifluorite-type ordering, where the stoichiometric fractions are Li=1, M2+=1, and GV=1. Electron-hole pairs are created by absorption of radiation, and the electron-hole pairs are detected by the current they generate between the anode and the cathode. The anode may include an array of pixels to provide improved spatial and energy resolution over the face of the anode. The signal value for each pixel can be mapped to a color or grey scale normalized to all the other pixel signal values for a particular moment in time. A guard ring or guard grid may be provided to reduce leakage current.

Abstract: A radiation detector includes a neutron sensing element comprising a neutron scintillating composite material that emits a first photon having a first wavelength and an optical waveguide material having a wavelength-shifting dopant dispersed therein that absorbs the first photon emitted by the neutron scintillating composite material and emits a second photon having a second, different wavelength, and a functionalized reflective layer at an interface between the neutron scintillating composite material and the optical waveguide material. The functionalized reflective layer allows the first photon emitted by the neutron scintillating composite material to pass through and into the optical waveguide material, but prevents the second photon emitted by the optical waveguide material from passing through and into the neutron scintillating composite material.

Abstract: Moldable neutron sensitive compositions containing an inorganic scintillating component, and neutron capture component, and a moldable resin component, are described. They are prepared with optimized compositions for maximized thermal neutron sensitivity. Methods for preparing such compositions, and articles and radiation detectors made from them are described as well.

Abstract: A radiation detector includes a neutron sensing element having a neutron scintillating material at least partially surrounded by an optical waveguide material; and a photosensing element optically coupled to the neutron sensing element. The photons emitted from the neutron sensing element are collected and channeled through the optical waveguide material and into the photosensing element.

Abstract: An integrated neutron-gamma radiation detector includes a gamma sensing element, a neutron sensing element comprising a neutron scintillating material at least partially surrounded by an optical waveguide material, and a photosensing element optically coupled to both the gamma sensing element and the neutron sensing element. A portion of the gamma sensing element is capable of being disposed within a central aperture of the neutron sensing element. In one aspect, the neutron sensing element comprises a plurality of cylindrical, concentric shells forming the central aperture for receiving the gamma sensing element. In another aspect, the neutron sensing element comprises a plurality of strands forming a multi-layered structure and forming the central aperture for receiving the gamma sensing element.

Abstract: A semiconductor material for radiation absorption and detection comprising a composition of stoichiometry Li(M12+, M22+, M32+, . . . )(G1V, G2V, G3V, . . . ) and exhibiting an antifluorite-type order, where Li=1, (M12++M22++M32++ . . . )=1, and (G1V+G2V+G3V+ . . . )=1. The material provides two useful characteristics: [1] a high Li-site density, which when enriched in 6Li, produces exceptional neutron-absorbing capabilities and [2] a semiconducting band-gap for the efficient conversion of absorbed photon and neutron energies into electrical currents. These characteristics can be exploited in applications for power generation or the spectroscopic detection of gamma and neutron radiation. The material can be tailored so as to detect only gamma photons, detect only neutron particles, or simultaneously detect gamma photons and neutron particles.

Abstract: An integrated radiation detector having a pulse-mode operating photosensor optically coupled to a gamma sensing element and a neutron sensing element is disclosed. The detector includes pulse shape and processing electronics package that uses an analog to digital converter (ADC) and a charge to digital converter (QDC) to determine scintillation decay times and classify radiation interactions by radiation type. The pulse shape and processing electronics package determines a maximum gamma energy from the spectrum associated with gamma rays detected by the gamma sensing element to adaptively select a gamma threshold for the neutron sensing element. A light pulse attributed to the neutron sensing element is a valid neutron event when the amplitude of the light pulse is above the gamma threshold.

Abstract: An integrated neutron-gamma radiation detector includes a gamma sensing element, a neutron sensing element comprising a neutron scintillating material at least partially surrounded by an optical waveguide material, and a photosensing element optically coupled to both the gamma sensing element and the neutron sensing element. A portion of the gamma sensing element is capable of being disposed within a central aperture of the neutron sensing element. In one aspect, the neutron sensing element comprises a plurality of cylindrical, concentric shells forming the central aperture for receiving the gamma sensing element. In another aspect, the neutron sensing element comprises a plurality of strands forming a multi-layered structure and forming the central aperture for receiving the gamma sensing element.

Abstract: A method for localizing optical emission is disclosed. The method involves identifying a first readout channel of a first pixellated photodetector array based on an impact of a first photon on the first pixellated photodetector array. The first photon is emitted by a scintillator unit of a scintillator array and the first readout channel corresponds to a column of one or more pixels of the first pixellated photodetector array. The method also involves identifying a second readout channel of a second pixellated photodetector array based on an impact of a second photon on the second pixellated photodetector array. The second photon is emitted by the scintillator unit and the second readout channel corresponds to a row of one or more pixels of the second pixellated photodetector array. The method further involves identifying the scintillator unit based on the first readout channel and the second readout channel.

Abstract: Moldable neutron sensitive compositions containing an inorganic scintillating component, and neutron capture component, and a moldable resin component, are described. They are prepared with optimized compositions for maximized thermal neutron sensitivity. Methods for preparing such compositions, and articles and radiation detectors made from them are described as well.

Abstract: An integrated radiation detector having a pulse-mode operating photosensor optically coupled to a gamma sensing element and a neutron sensing element is disclosed. The detector includes pulse shape and processing electronics package that uses an analog to digital converter (ADC) and a charge to digital converter (QDC) to determine scintillation decay times and classify radiation interactions by radiation type. The pulse shape and processing electronics package determines a maximum gamma energy from the spectrum associated with gamma rays detected by the gamma sensing element to adaptively select a gamma threshold for the neutron sensing element. A light pulse attributed to the neutron sensing element is a valid neutron event when the amplitude of the light pulse is above the gamma threshold.

Abstract: A method and apparatus for discriminating the types of radiation interacting with an integrated radiation detector having of a pulse-mode operating photosensor which is optically coupled to a gamma-ray scintillator sensor and a neutron scintillator sensor and uses an analog to digital converter (ADC) and a charge to digital converter (QDC) to determine scintillation decay times and classify radiation interactions by radiation type. The pulse processing provides for, among other things, faithful representation of the true energy spectrum of the gamma radiation field and allows for radioisotope identification by searching for the presence of characteristic energy lines in the gamma energy spectrum. The pulse shape discrimination method ensures that the high sensitivity and resolution of the isotope identification function is not affected during operation in mixed neutron-gamma fields.

Abstract: A method for identifying localized optical emission is disclosed. The method involves identifying a region, which corresponds to a plurality of scintillator units of a scintillator, on a position sensitive photodetector that is impacted by one or more photons. The method further involves identifying a readout channel of a pixellated photodetector array that corresponds to a pixel associated with a scintillator unit impacted by the one or more photons. The method, further involves, identifying the scintillator unit based on the region and the readout channel.

Abstract: A sensing element or detector activated by radiation comprising a first scintillator activated by gamma radiation; and a neutron sensing layer comprising a second scintillator activated by neutron radiation.