583results about "Measurement with scintillation detectors" patented technology

An apparatus for selective radiation detection includes a neutron detector that facilitates detection of neutron emitters, e.g. plutonium, and the like; a gamma ray detector that facilitates detection of gamma ray sources, e.g., uranium, and the like; and/or an X-ray analyzer that facilitates detection of materials that can shield radioactive sources, e.g., lead, and the like.

The present invention provides a gamma-neutron detector based on mixtures of thermal neutron absorbers that produce heavy-particle emission following thermal capture. The detector consists of one or more thin screens embedded in transparent hydrogenous light guides, which also serve as a neutron moderator. The emitted particles interact with the scintillator screen and produce a high light output, which is collected by the light guides into a photomultiplier tube and produces a signal from which the neutrons are counted. Simultaneous gamma-ray detection is provided by replacing the light guide material with a plastic scintillator. The plastic scintillator serves as the gamma-ray detector, moderator and light guide. The neutrons and gamma-ray events are separated employing Pulse-Shape Discrimination (PSD). The detector can be used in several scanning configurations including portal, drive-through, drive-by, handheld and backpack, etc.

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.

A broad spectrum neutron detector has a thermal neutron sensitive scintillator film interleaved with a hydrogenous thermalizing media. The neutron detector has negligible sensitivity to gamma rays and produces a strong and unambiguous signal for virtually all neutrons that interact with the hydrogenous volume. The interleaving of the layers of thermal neutron sensitive phosphors helps ensure that all parts of the thermalizing volume are highly sensitive.

A detector and methods for inspecting material on the basis of scintillator coupled by wavelength-shifting optical fiber to one or more photo-detectors, with a temporal integration of the photo-detector signal. An unpixelated volume of scintillation medium converts energy of incident penetrating radiation into scintillation light which is extracted from a scintillation light extraction region by a plurality of optical waveguides. This geometry provides for efficient and compact detectors, enabling hitherto unattainable geometries for backscatter detection and for energy discrimination of incident radiation. Additional energy-resolving transmission configurations are enabled as are skew- and misalignment compensation.

A positron emission tomography detector for a multilayer scintillation crystal comprises a plurality of layers of scintillation crystals, a photoelectric detector system and an algorithm system, wherein the multilayer scintillation crystals comprises n layers of array scintillation crystals and m layers of continuous scintillation crystals, both n and m are integers which are greater than or equal to 1, the sum of n and m is smaller than or equal to 10, the array scintillation crystals are formed by arraying strip-type scintillation crystals along the width and length directions, the continuous scintillation crystals are scintillation crystals which have uncut inner parts, the array scintillation crystals and the continuous scintillation crystals are sequentially coupled along the height direction of the strip-type scintillation crystals to form the multilayer scintillation crystals, and the bottoms of the continuous scintillation crystals are coupled with the photoelectric detector system. The positron emission tomography detector can more accurately obtain the position and the time of energy deposition of gamma photon in the scintillation crystal, and has higher detection efficiency of the gamma photon, the spatial resolution, the time resolution and the flexibility of a positron emission tomographic imaging system can be improved when the positron emission tomography detector is applied to the positron emission tomographic imaging system, and further, the imaging quality of the system can be improved.

The present invention provides a gamma-neutron detector based on mixtures of thermal neutron absorbers that produce heavy-particle emission following thermal capture. The detector consists of one or more thin screens embedded in transparent hydrogenous light guides, which also serve as a neutron moderator. The emitted particles interact with the scintillator screen and produce a high light output, which is collected by the light guides into a photomultiplier tube and produces a signal from which the neutrons are counted. Simultaneous gamma-ray detection is provided by replacing the light guide material with a plastic scintillator. The plastic scintillator serves as the gamma-ray detector, moderator and light guide. The neutrons and gamma-ray events are separated employing Pulse-Shape Discrimination (PSD). The detector can be used in several scanning configurations including portal, drive-through, drive-by, handheld and backpack, etc.

The present invention provides a gamma-neutron detector based on mixtures of thermal neutron absorbers that produce heavy-particle emission following thermal capture. In one configuration, B-10 based detector is used in a parallel electrode plate geometry that integrates neutron moderating sheets, such as polyethylene, on the back of the electrode plates to thermalize the neutrons and then detect them with high efficiency. The moderator can also be replaced with plastic scintillator sheets viewed with a large area photomultiplier tube to detect gamma-rays as well. The detector can be used in several scanning configurations including portal, drive-through, drive-by, handheld and backpack, etc.

A scintillator system is provided to detect the presence of fissile material and radioactive material. One or more neutron detectors are based on 6LiF mixed in a binder medium with scintillator material, and are optically coupled to one or more wavelength shifting fiber optic light guide media that have a tapered portion extending from the scintillator material to guide light from the scintillator material to a photosensor at the tapered portion. An electrical output of the photosensor is connected to an input of a first pre-amp circuit designed to operate close to a pulse shape and duration of a light pulse from the scintillator material, without signal distortion. The scintillator material includes a set of scintillation layers connected to the wavelength shifting fiber optic light guide media that guide light to the photosensor. Moderator material is applied around the set of scintillation layers increasing detector efficiency.

A neutron detector has a volume of neutron moderating material and a plurality of individual neutron sensing elements dispersed at selected locations throughout the moderator, and particularly arranged so that some of the detecting elements are closer to the surface of the moderator assembly and others are more deeply embedded. The arrangement captures some thermalized neutrons that might otherwise be scattered away from a single, centrally located detector element. Different geometrical arrangements may be used while preserving its fundamental characteristics. Different types of neutron sensing elements may be used, which may operate on any of a number of physical principles to perform the function of sensing a neutron, either by a capture or a scattering reaction, and converting that reaction to a detectable signal. High detection efficiency, an ability to acquire spectral information, and directional sensitivity may be obtained.

A neutron detector composed of a matrix of scintillating particles imbedded in a lithiated glass is disclosed. The neutron detector detects the neutrons by absorbing the neutron in the lithium-6 isotope which has been enriched from the natural isotopic ratio to a commercial ninety five percent. The utility of the detector is optimized by suitably selecting scintillating particle sizes in the range of the alpha and the triton. Nominal particle sizes are in the range of five to twenty five microns depending upon the specific scintillating particle selected.

A device for detecting radiation includes a substantially transparent substrate with one or more substantially transparent scintillating films patterned onto the surface and with one or more integrated waveguides such that radiation of differing species may be detected by an optical light detector and such that the composition of the radiation may be analyzed. A scintillating material for detecting individual species of radiation and including one or more groups of nanoparticles mixed with a fast electron scintillating material and extruded into a transparent film such that a light pulse is emitted when said transparent film is exposed to the species of radiation targeted by the nanoparticle groups.