37 results about "Gamma ray detectors" patented technology

A positron emission tomography (PET) scanner may include a plurality of gamma radiation detector modules arranged to form a detector ring. Each detector module may include an array of elongated scintillation crystals. With respect to the detector ring, each elongated scintillation crystal includes a proximal end-face, two axially oriented lateral faces, two transaxially oriented lateral faces, and a distal end-face radially oriented into the detector ring to receive a gamma photon. An array of photosensors is positioned along a first of the axially oriented lateral faces of each elongated scintillation crystal to detect scintillation photons. A reflective material is positioned on the proximal end-face, the distal end-face, the transaxially oriented lateral faces, and a second of the axially oriented lateral faces of each elongated scintillation crystal to internally reflect scintillation photons. In various embodiments, a dual-channel processing circuit provides distinct timing and energy signals from the photosensors.

Techniques of performing gamma ray coincidence detection are provided. The techniques include identifying, using a first voltage data signal obtained using at least one gamma ray detector disposed adjacent to a sample material, a first time value corresponding to a leading edge of the first voltage data signal and identifying, using a second voltage data signal obtained using the at least one gamma ray detector, a second time value corresponding to a leading edge of the second voltage data signal. The techniques further include determining, using the first and second time values, a time difference value and determining whether the time difference value is greater than or less than a threshold coincidence value to identify whether the sample material underwent a sequential radiative transition.

The invention relates to the technical field of nondestructive testing of element content and uniformity of fuel elements, and provides a fuel element detection method and system based on neutron imaging and activation analysis. The detection method comprises the following steps: S1, installing a to-be-detected sample, and adjusting an imaging collimation hole to be aligned with a neutron beam current of a neutron source; s2, the thermal neutrons are collimated by the imaging collimation hole and then transmit the to-be-detected sample, and spatial distribution of uranium and poison elements of the to-be-detected sample is obtained through detection of a neutron imaging detector; s3, selecting a specific target area, switching the activation analysis collimation hole to align to a neutron beam of the neutron source, and adjusting the position of the to-be-detected sample, so that the specific target area aligns to the neutron beam of the neutron source; thermal neutrons bombard a specific target area after being collimated by the activation collimation hole, and are received by the gamma ray detector so as to analyze and obtain the element content of the specific target area. According to the method, distribution and content of uranium and toxic elements in the fuel element can be rapidly and accurately determined on the premise of nondestructive testing.

Methods and apparatus for using exempt gamma photon sources to measure fluid properties are described herein. The gamma photon sources are used with detectors in an arrangement that provides a short photon path length between source and detector. Fluid measurement devices described herein have a fluid container defining an interior, an exempt gamma-ray source located outside the fluid container, and a gamma-ray detector located outside the fluid container, the exempt gamma photon source and the gamma-ray detector defining a photon path that traverses the interior of the fluid container along a non-diametric chord of the fluid container.

The application discloses a water body radioactivity online monitoring system and a monitoring method, and relates to the technical field of water body radioactivity monitoring. The monitoring system comprises a probe device, a probe driver and signal processing device and a data processing device. The probe device comprises a beta particle detector and a gamma ray detector, and is used for detecting beta particles and gamma rays in a water body and outputting detection signals. The probe driver and signal processing device is electrically connected with the beta particle detector and the gamma ray detector, and is used for receiving the detection signals, processing the detection signals and outputting detection data. The data processing device is electrically connected with the probe driver and signal processing device, and is used for receiving the detection data and analyzing the detection data to obtain a monitoring result. The system provided by the application can realize online real-time monitoring of water body radioactivity, and can realize monitoring of water body nuclide content and identification of nuclides.

Methods and apparatus are disclosed for concurrent digital autoradiography of alpha-particle events and positron events using a spatially resolving charged particle detector and a gamma-ray detector. Alpha particles and positrons are detected by the charged particle detector. Positrons are identified based on coincidence with gamma-ray events. A positron-emission autoradiograph is formed based on positron positions. Alpha particles, both coincident and anticoincident with positrons, are identified based on energy deposition patterns. An alpha-emission autoradiograph is formed based on alpha-particle positions and energies. Separation of coincident alpha and positron events recorded by the charged particle detector improves position detection accuracy. Validation of positron imaging for alpha-emitter distribution or dosage, based on correlation of respective autoradiographs, is described. Variations for particle identification based on isotropy, energy, coincidence, or anticoincidence are presented. Disclosed techniques are applicable to alpha-emitting radionuclides with complex decay chains.

The invention discloses a single-layer Compton camera system and an imaging method, and relates to the technical field of nuclear radiation imaging. The system comprises a single-plane pixel type gamma ray detector used for collecting gamma ray interaction event data, including time information and energy information of each interaction and two-dimensional position information in a detector plane, and forming pixel counting distribution; the shielding structure is arranged on one side of the plane of the detector, is located in a local area of the detector and is used for enabling pixel counting distribution to generate a local counting missing feature when gamma rays are incident from one side where the shielding structure is located; and the judging and imaging module is used for judging a gamma ray incident side based on the local counting missing feature and executing Compton imaging reconstruction in a corresponding hemispherical view field range according to the judged incident side. According to the invention, partitioned omnidirectional imaging can be carried out on the radioactive source under the condition that a detector does not need to act on depth information, and meanwhile, generation of mirror image artifacts is avoided.

To provide both good time-of-flight resolution and interaction depth information. [Solution] The positron emission tomography apparatus according to the embodiment comprises a scintillation array and a photosensor array. The scintillation array includes a plurality of scintillator crystal units individually separated by a reflective material, and each scintillator crystal unit is configured to generate scintillation light in response to gamma-ray interactions within the scintillator crystal unit caused by gamma-ray irradiation from a subject, and has a substructure for decoding two or more depths within the scintillator crystal unit such that gamma-ray interactions at different depths cause scintillation light to escape from the photo-escape plane of the scintillator crystal unit in different patterns. The photosensor array converts the scintillation light received from the scintillation array into an electrical signal.

The utility model relates to the field of medical instruments, in particular to a quick-release gamma ray detector probe which comprises a handle and a probe body. The handle comprises a handle body and a control panel, the control panel is arranged on the side face of the handle body, and the control panel is used for controlling the probe to conduct gamma ray detection analysis; the front end of the handle is provided with a Remo joint socket; the probe comprises a Remo joint plug, a fixed long rod and a probe; long rods with included angles are arranged at the two ends of the fixed long rod; the Remo joint plug is arranged at the tail part of the fixed long rod, and the probe is arranged at the front end of the fixed long rod; the Remo joint socket and the Remo joint plug are matched with each other; the probe is connected to the Remo connector plug through a wire arranged in the fixed long rod, and is finally connected to the control panel through cooperation of the Remo connector plug and the Remo connector socket. The probe is convenient to disassemble and split, and can be quickly disinfected before sentinel lymph node detection.

The invention relates to the technical field of radiation detection, in particular to a gamma ray detector and a gamma ray detection system. The detector comprises a substrate, a shading shell, a scintillation crystal, a silicon photomultiplier tube array, a first reflecting layer and a second reflecting layer, the shading shell is connected with the substrate so as to define an open inner cavity with the substrate; the scintillation crystal is located in the open inner cavity; the silicon photomultiplier tube array is located in the open inner cavity and is coupled with the scintillation crystal through an adhesive, and the silicon photomultiplier tube array is connected with the substrate to obtain electric energy; the first reflecting layer is arranged around the scintillation crystal; and the second reflecting layer is connected with a cavity opening of the open inner cavity to form a sealing structure. The invention has the advantages of magnetic interference resistance, miniaturization and high counting rate.

Neutron-induced radiation detectors (NiRDs) and radiation dosimetry systems containing the same are described. Examples of NiRDs can include numerous components based on location, function, dimension, and / or constituent materials. A NiRD can be configured to directly measure an absorbed dose (or rate) of particular ionizing reaction products induced by neutrons. The NiRD can utilize various detection schemes for measuring the deposited energy of the reaction products, such as gaseous ionization, semiconducting, scintillating, or homogenous versions of these detection schemes. The NiRD can measure the deposited energy of the reaction products in forward emission, backward emission, or both. Examples of radiation dosimetry systems can include one or more NiRDs, a gamma ray detector, and readout electronics coupled to each of the radiation detectors. Example implementations of the radiation dosimetry systems are described for determining an equivalent dose (or rate) of a neutron beam generated for boron neutron capture therapy (BNCT).

A gamma ray measurement tool has a tubular shell, a gamma ray detector disposed in the tubular shell, and a shield disposed between the tubular shell and the gamma ray detector. The gamma ray detector has a scintillation crystal coupled to a photomultiplier tube, and the shield has a open window configured to allow gamma rays to pass through and reach the scintillation crystal. Further, the tubular shell has a first axis in the longitudinal direction, and the gamma ray detector has a second axis in the longitudinal direction, the first axis and the second axis do not coincide with each other, and a distance between the scintillation crystal and an inner surface of the tubular shell through the window is shorter than a distance between the scintillation crystal and a portion of the tubular shell covered by the shield.

The invention particularly relates to a combined detector for an online sipping device. The combined detector comprises a beta-ray detector, a gamma-ray detector and a signal processing system, the beta ray detector adopts a plastic scintillation chamber with a high beta / gamma response ratio; the gamma ray detector adopts a scintillation crystal; the signal processing system is configured to perform beta-gamma coincidence measurement on output signals of the beta-ray detector and the gamma-ray detector; the plastic scintillation chamber is adjacent to the scintillation crystal space, and the detection areas of the plastic scintillation chamber and the scintillation crystal space are at least partially overlapped so as to jointly detect the detected gas flowing through the plastic scintillation chamber. The invention further relates to a nuclear fuel assembly damage detection method which adopts the combined detector. According to the invention, comprehensive detection of beta and gamma rays of radioactive inert gas is realized, and efficient and sensitive measurement of beta rays in large-volume radioactive inert gas is realized, so that the efficiency and accuracy of gamma-beta coincidence measurement are improved.

The invention provides a ray deposition process Boolean operation-based X / gamma ray detector passive efficiency scale calculation method, which belongs to the technical field of nuclear radiation measurement, and comprises the following steps: dispersing a radioactive source into a plurality of point radioactive sources in space, and obtaining ray angle distribution; analyzing to obtain the passing distance of the ray in the shielding body; calculating to obtain a line absorption coefficient; calculating the attenuation proportion of the shielding body; acquiring a ray deposition process in the sensitive body to form a scattering point coordinate matrix; performing coordinate system transformation on the ray deposition process to obtain a scattering point model, and performing graphic Boolean intersection operation on the scattering point model and the sensitive body; calculating the intrinsic detection efficiency of the rays; and calculating the radioactive source detection efficiency according to the ray angle distribution, the attenuation ratio and the intrinsic detection efficiency. According to the technical scheme provided by the invention, rapid and accurate passive efficiency calibration can be carried out, and a reliable and efficient solving technology is provided for large-volume long-distance radioactive source calibration.

The invention relates to the technical field of radioactivity measurement, in particular to radioactivity on-line monitoring of mineral products such as coal and iron ore, which comprises a radioactivity detection module for radioactivity on-line monitoring, an alarm output module when the radioactivity intensity of the mineral products exceeds the standard, and a measurement and control module for realizing measurement control, the radioactivity detection module is provided with a gamma ray detector; the radioactivity detection module is installed above a mineral product conveying line; the whole set of system is further provided with a positioning module to realize mineral product radioactive intensity standard exceeding positioning, and is provided with a nuclide identification module to realize nuclide type identification. A gamma dose equivalent rate module is configured to measure the dose equivalent rate; the problem that an existing online radioactivity monitoring system cannot be used for online radioactivity monitoring of mineral products is solved, and online radioactivity monitoring of the mineral products is achieved.

The disclosure provides a low-orbit neutron and gamma-ray detector group, a detection device and a detection method. The detection device is a small-volume, small-mass, low-power and high-speed neutron / gamma spectrometer based on a multi-layer single / dual sensitive area Si detector and a cadmium zinc telluride (CZT) detector array. The neutron / gamma spectrometer can be carried on a small satellite as an independent load to measure thermal neutrons, fast neutrons below 20 MeV and gamma rays. The cooperation between different layers of the detector group in the detection device forms multiple anticoincidence groups, improving the accuracy of energy spectrum inversion. The detection method proposes a pile discarding algorithm, thereby avoiding the interference caused by signal overlap and improving the system resolution of the entire neutron / gamma spectrometer.

A downhole system may include a downhole tubular having a body portion formed between a central bore and a radially outer surface of the downhole tubular, a neutron generator housed within the body portion and configured to emit neutrons, and a gamma ray detector housed within the body portion and configured to detect gamma rays formed via interactions between the emitted neutrons and a downhole formation. The downhole system may also include a sleeve disposed about the radially outer surface of the downhole tubular. The sleeve may be axially positioned over at least a portion of the gamma ray detector. Additionally, the downhole system may include a thermal neutron absorption layer disposed between a radially outer surface of the sleeve and the gamma ray detector.

The application discloses a kind of fully mechanized coal face coal-rock interface simulation identification method and intelligent coal winning machine, 1, construct the inversion model of coal-rock interface based on the eigenvalue of radiation field;2, when coal seam thickness h=0, the radiation intensity measured by gamma ray detector in rock stratum P point is J0, is calculated to obtain relevant parameter value in the inversion model of coal-rock interface;3, set horizontal direction span Δ, set i=1, with X i Point as detection starting point detects its corresponding radiation intensity J i ;4, the radiation intensity J i It is calculated in the inversion model of coal-rock interface to predict the fluctuation slope τ of next section coal-rock interface;5, according to current detection point X i Position, predicted coal-rock interface fluctuation slope τ and horizontal direction span Δ determine next detection point X i+1 Position;6, judge whether simulation is finished or not. Realize the dynamic tracking of coal-rock interface situation, realize the coal-rock interface simulation identification of fully mechanized coal face, guide intelligent coal winning machine to cut coal.

To provide a radiation monitoring system that can determine a critical margin of an object including nuclear fuel with partially unknown characteristics.SOLUTION: A radiation monitoring system is configured to include a gamma-ray detector for measuring gamma rays, a gamma-ray energy analysis device for analyzing gamma-ray energy from the output of the gamma-ray detector, a neutron detector for measuring neutrons, a neutron flux analysis device for analyzing neutron flux from the output of the neutron detector, an inverse multiplication analysis device for calculating inverse multiplication data based on a high-energy gamma-ray dose and an alternative gamma-ray dose acquired from the gamma-ray energy analysis device and a neutron flux acquired from the neutron flux analysis device, and an inverse multiplication curve processing device for calculating a critical margin from the high-energy gamma-ray dose and the inverse multiplication data.SELECTED DRAWING: Figure 1

A concentration detector includes: a neutron source emitting neutrons to a target; a gamma ray detector detecting and determining an amount of specific gamma rays that are among gamma rays generated in the target by interactions with the neutrons; and a concentration calculator calculating a concentration of the target at selected depths in the inspection target, based on the detected amount. A relational expression expressing a relation between a plurality of concentrations of the target in a plurality of virtual layers and a detected amount of the specific gamma rays is predetermined for each type of the specific gamma rays or each detection condition. The concentration calculator applies the detected amount for each gamma ray type or each detection condition, to the relational expression for the type or the detection condition, and calculates a concentration of the target component in the layer at each depth or the specific depth.

This invention provides a multi-channel SiPM data acquisition system, method, SiPM-type gamma-ray detector, and composite detector system. In the data acquisition system, an ASIC chip compares the amplified SiPM signal with preset trigger selection conditions. If the amplified SiPM signal meets the trigger selection conditions, a first trigger signal is sent to the FPGA control board. The FPGA control board sends parameter configuration signals to the ASIC chip, controlling the configuration of the ASIC chip's parameters. Upon receiving the first trigger signal from the ASIC chip, it outputs a first control signal and a second control signal. This invention improves debugging efficiency, fully utilizes the positional sensitivity of the SiPM array, effectively reduces signal saturation problems caused by parallel readouts, and achieves a large signal dynamic range.

A first aspect of the invention relates to a system for the in-line preparation of a vitrifiable mixture having a target composition, the system comprising: - a unit for dispensing raw materials, which is able to provide a premix comprising cullet, preferably at least 20% by weight of cullet; - a conveyor which is able to move the premix; - a unit for the in-line measurement of the composition of the premix by neutron activation, the in-line measurement unit comprising: • at least one neutron emission source configured to irradiate all or part of said premix; • at least one gamma ray detector configured to detect the gamma rays emitted by the premix when it is irradiated by the neutron emission source; and • a digital processing device configured to calculate, from the signal of the gamma ray detector, the content of chemical elements present in the premix, and optionally configured to estimate the water content and / or the content of organic compounds in the premix; and - at least one means for adjusting the premix to obtain the vitrifiable mixture having the target composition. The invention also relates to a method for the in-line preparation of a vitrifiable mixture having a target composition.

The application discloses a gamma logging instrument principle demonstration simulation device and method, and belongs to the field of well logging principle demonstration. The device comprises a cylinder for simulating a formation model; the cylinder is arranged vertically and has different light transmittances at different heights of the cylinder; a photosensitive resistance device is arranged in the interior of the cylinder for replacing a gamma ray detector; the photosensitive resistance device is connected with driving devices for driving the photosensitive resistance device to move up and down; the photosensitive resistance device is also connected with a linear voltage-controlled oscillator through wires, the linear voltage-controlled oscillator is connected with a voltage comparator, the voltage comparator is connected with a counter, and the counter is connected with a single-chip microcomputer. The application can convert different light intensities into electric pulse signals with different frequencies, and then count square wave pulses output by the voltage comparator in a unit time through the counter, so that gamma logging simulation is realized. The application simplifies the structure and scale of a measuring device and a simulated formation in a demonstration process, and enhances the convenience and intuitiveness of relevant demonstration operations.

A downhole system may include a downhole tubular having a body portion formed between a central bore and a radially outer surface of the downhole tubular, a neutron generator housed within the body portion and configured to emit neutrons, and a gamma ray detector housed within the body portion and configured to detect gamma rays formed via interactions between the emitted neutrons and a downhole formation. The downhole system may also include a sleeve disposed about the radially outer surface of the downhole tubular. The sleeve may be axially positioned over at least a portion of the gamma ray detector. Additionally, the downhole system may include a thermal neutron absorption layer disposed between a radially outer surface of the sleeve and the gamma ray detector.

The invention discloses a method for growing an MAPbBr3 single crystal through a mixed solvent and a gamma ray detector, and relates to the technical field of semiconductor material preparation and radiation detection.The method comprises the steps that a precursor solution is prepared through the mixed solvent of DMF and DMSO, and the low-defect-density and large-size MAPbBr3 single crystal is obtained through growth at the precisely-controlled heating rate through a temperature inversion crystallization technology; according to a gamma ray detector constructed based on the single crystal, a Bi / MAPbBr3 / Au asymmetric electrode structure is adopted, and surface polishing treatment and protection ring design are combined, so that dark current and noise are remarkably reduced; according to the method, the dissolution-crystallization thermodynamic and dynamic behaviors of MAPbBr3 are regulated and controlled through the DMF-DMSO mixed solvent, controllable growth of low-defect-density single crystals is achieved, and the high-performance room-temperature gamma ray detector is constructed in combination with surface defect repair and asymmetric electrode energy band engineering.

According to a first aspect, the invention relates to an online preparation system for a vitrifiable mixture of target composition, the system comprising: - a raw material distribution unit capable of supplying a premix comprising cullet, preferably at least 20% by mass of cullet; - a conveyor capable of moving the premix; - an online measurement unit for the composition of the premix by neutron activation, the online measurement unit comprising: • at least one neutron emission source configured to irradiate all or part of said premix; • at least one gamma ray detector configured to detect the gamma rays emitted by the premix when it is irradiated by the neutron emission source;and • a digital processing device configured to calculate, from the gamma ray detector signal, the chemical element content present in the premix, and optionally configured to estimate the water content and / or the organic compound content in the premix; and at least one means for adjusting the premix to obtain the vitrifiable mixture of target composition. The invention also relates to a method for preparing a vitrifiable mixture of target composition online. Figure 1.

A method for determining real-time thermal power of a nuclear reactor based on number of gamma rays counted comprising measuring a number of gamma-ray counts by a gamma-ray detector that is placed outside a biological shield at a primary cooling circuit of a fission nuclear power plant so that maintenance of the detector is possible during normal operation of the fission nuclear power plant, and determining, by a computing device in real-time, a thermal power of the fission nuclear power plant based on the number of gamma-ray counts measured by the gamma-ray detector.

Methods and apparatus are disclosed for concurrent digital autoradiography of alpha-particle events and positron events using a spatially resolving charged particle detector and a gamma-ray detector. Alpha particles and positrons are detected by the charged particle detector. Positrons are identified based on coincidence with gamma-ray events. A positron-emission autoradiograph is formed based on positron positions. Alpha particles, both coincident and anticoincident with positrons, are identified based on energy deposition patterns. An alpha-emission autoradiograph is formed based on alpha-particle positions and energies. Separation of coincident alpha and positron events recorded by the charged particle detector improves position detection accuracy. Validation of positron imaging for alpha-emitter distribution or dosage, based on correlation of respective autoradiographs, is described. Variations for particle identification based on isotropy, energy, coincidence, or anticoincidence are presented. Disclosed techniques are applicable to alpha-emitting radionuclides with complex decay chains.

A downhole tool is equipped with a neutron generator configured to emit neutrons into a geological formation. The downhole tool includes one or more neutron detectors configured to detect neutrons that return to the downhole tool upon interaction with the geological formation. The downhole tool further includes one or more gamma ray detectors configured to detect gamma rays from the geological formation, the gamma rays being formed when the neutrons are inelastically scattered by the geological formation. Formation density is determined using measurements from a detector combination of at least one of the one or more neutron detectors and at least one of the one or more gamma ray detectors. The first formation density determined using the first detector combination is used to compensate for the second formation density determined using the second detector combination.

A nanosecond neutron analysis and associated particle imaging system (NNA / API) and a gamma ray detector device (i.e., a device) are disclosed that utilizes the associated element detection of titanium, iron, and oxygen to determine the concentration of ilmenite or other minerals associated with He-3 in extraterrestrial bodies. The device is used with a movable carrier to map the concentration of possible He-3 regions on extraterrestrial bodies.