Abstract: The attenuation and other optical properties of a medium are exploited to measure a thickness of the medium between a sensor and a target surface. Disclosed herein are various mediums, arrangements of hardware, and processing techniques that can be used to capture these thickness measurements and obtain three-dimensional images of the target surface in a variety of imaging contexts. This includes general techniques for imaging interior/concave surfaces as well as exterior/convex surfaces, as well as specific adaptations of these techniques to imaging ear canals, human dentition, and so forth.

Abstract: Apparatus for detecting ionizing radiation includes a mobile telephone, including an imaging assembly, which includes a solid-state image sensor. A radiation converter is mounted in proximity to the image sensor and is configured to emit, in response to the ionizing radiation, lower-energy radiation for detection by the image sensor. A processor, contained in the mobile telephone, is configured to process images captured by the image sensor so as to assess an intensity of the ionizing radiation.

Abstract: An imaging detector includes a scintillator having a scintillator pixel that is configured to emit light. The detector also includes a photosensor that defines a photosensor pixel that is configured to absorb light emitted by the scintillator pixel. A lens is positioned between the scintillator pixel and the photosensor pixel for directing light emitted from the scintillator to the photosensor pixel. The lens is configured to converge light emitted from the scintillator pixel toward the photosensor pixel.

Abstract: A radiation therapy system including a linear accelerator configured to emit a beam of radiation and a dosimeter configured to detect in real-time the beam of radiation emitted by the linear accelerator. The dosimeter includes at least one linear array of scintillating fibers configured to capture radiation from the beam at a plurality of independent angular orientations, and a detection system coupled to the at least one linear array, the detection system configured to detect the beam of radiation by measuring an output of the scintillating fibers.

Abstract: The present disclosure relates to a method and an apparatus for identifying line-of-responses (LOR) of photons. A radiation detection machine measures the photons. LOR identification errors are then mitigated using pattern recognition of the measurements. In some embodiments, the photons may comprise positron annihilation photons, each position annihilation photon being associated with one or more scattered photons. In yet some embodiments, pattern recognition may be implemented in a neural network.

Abstract: A method for estimating the start time of an electronic pulse generated in response to a detected event, for example the start time for pulses received in response to photon detection in positron emission tomography, includes providing a detector that detects an external event and generates an electronic analog pulse signal. A composite reference pulse curve is calculated to represent analog pulse signals generated by the detector. Upon receiving an analog pulse signal, it may be filtered, and then digitized, and normalized based on the area of the digital signal. Using at least one point of the normalized digital pulse signal, the composite reference pulse curve shape is used to estimate the pulse start time.

Abstract: Provided are devices and methods for quantifying a surface's cleanliness relative to a contaminant. Such devices and methods may comprise and/or use a source of interrogating radiation to which the contaminant is responsive, a means for directing the interrogating radiation, a detector, and an analyzer. Radiation emitted from the source is directed by the radiation means toward an article having the surface or comprising a surface cleaner that may hold the contaminant. The detector detects radiation from the article produced in response to the interrogating radiation by the contaminant, e.g., fluorescent or phosphorescent radiation, and generate a corresponding signal that is compared by the analyzer relative to an electronic standard that corresponds to the surface in an acceptably clean state so as to quantify the surface's cleanliness.

Abstract: When employing hygroscopic scintillation crystals (32) in a nuclear detector (e.g., PET or SPECT), Silicon photo-multiplier (SiPM) sensors (34) are coupled to each scintillation crystal (32) to improve scintillation event detection and reduce scatter. The crystals (32) and sensors (34) are hermetically sealed in a detector housing (50) using a sealant layer (51). Electrical contacts (60) from each sensor (34) extend through the sealant layer (51) or are bused together such that the bus extends through the sealant layer (51). In this manner, hygroscopic scintillation crystals (e.g., LaBr, NaI, etc.) are protected from humidity and light scatter is reduced by direct coupling of the sensors (34) and crystals (32).

Abstract: One embodiment disclosed relates a method of detecting a patterned electron beam. The patterned electron beam is focused onto a grating with a pattern that has a same pitch as the patterned electron beam. Electrons of the patterned electron beam that pass through the grating un-scattered are detected. Another embodiment relates to focusing the patterned electron beam onto a grating with a pattern that has a second pitch that is different than a first pitch of the patterned electron beam. Electrons of the patterned electron beam that pass through the grating form a Moiré pattern that is detected using a position-sensitive detector. Other embodiments, aspects and features are also disclosed.

Abstract: A radiation detector includes a sensor panel, a scintillator panel, a reflective layer, and a radiation irradiation detecting photodetector laminated in this order from a side of a radiation receiving surface. Radiation transmitted through a patient's body enters the scintillator panel through the sensor panel, and is converted into light. The converted light propagates through columnar crystals in the scintillator panel with total internal reflection. Apart of the light reaches the sensor panel, while the remains reach the reflective layer. The light reaching the sensor panel is detected by photoelectric converters. Out of the light reaching the reflective layer, a short wavelength component with a relatively high refractive index is specularly reflected to the sensor panel. A long wavelength component with a relatively low refractive index is transmitted through the reflective layer, and enters the radiation irradiation detecting photodetector, which detects a start of radiation irradiation.

Abstract: A method for creating a look-up table includes arranging a mask configured to cover a subset of crystals of a plurality of crystals in a scintillation array. The method includes collecting a first set of data from at least one photosensor positioned to receive light generated by the scintillation array. The method further includes realigning the mask in a second position on the scintillation array to cover a second subset of crystals of the plurality of crystals. Further, the method includes collecting a second set of data from the at least one photosensor with the mask aligned on the scintillation array in the second position. Additionally, the method includes creating first and second flood histograms from the first and second sets of collected data, respectively. The method also superimposing the first flood histogram with the second flood histogram to create a superimposed flood histogram.

Abstract: Disclosed is an apparatus and method of acquiring images created by penetration of a radioactive ray. The apparatus includes a scintillator to generate a light signal in response to an irradiated radioactive ray, and to change an advancing direction of the generate light signal, a light receiving unit to receive the light signal whose advancing direction is changed, and a signal processing unit to convert the received light signal into an electrical signal, and acquire an image corresponding to the penetrated irradiated radioactive ray based on the converted electrical signal.

Abstract: A radiation detecting apparatus of this invention includes an arithmetic processing device which has a first adding step for adding signal strengths in one portion of a two-dimensional position map, draws respective boundaries based on results of addition in the first adding step, and corrects the two-dimensional position map based on signal strengths enclosed by these boundaries. The signal strengths of one portion of the two-dimensional position map, and not all the areas of the two-dimensional position map, are added. As a result, incident positions can be discriminated efficiently, and radiation detecting positions can be determined efficiently.

Abstract: The invention relates to a detector (110) for the detection of ionizing radiation (116). The detector (110) comprises at least one scintillator (112) which is adapted to convert the ionizing radiation (116) to electromagnetic radiation (118), especially to visible, ultraviolet or infrared light. The detector (110) further comprises at least one organic photovoltaic element (114) which is adapted to convert the electromagnetic radiation (118) to at least one electrical signal (120).

Abstract: Embodiments of the invention provide a scintillator material, a scintillator system, and/or a method of detecting incident radiation using a scintillator material, or scintillator system, comprising a polymer material that comprises chromophores. Additional embodiments provide a scintillator material, scintillator system, and/or a method of detecting incident radiation using a scintillator material, or scintillator system, comprising a polymer material having one, two, three, or more, organic dyes dissolved therein wherein the polymer material having the one, two, three, or more dyes dissolved therein comprises chromophores. At least one of the dyes, termed the base dye, has a concentration in the range 0.5 to 3.5 mol/L. In a specific embodiment, the base dye has a concentration in the range 1.0 to 3.0 mol/L. This base dye concentration is high enough to achieve a substantial triplet-triplet state annihilation rate despite the negligible diffusion of the dye in the rigid polymer matrix.

Abstract: A radiographic image capturing system includes a radiographic image capturing device, a grid, an acquiring unit, and a processor. The radiographic image capturing device includes a radiation detector in which pixels having a sensitivity with respect to radiation or light are disposed two-dimensionally at a predetermined pixel spacing. The grid is placed on a radiation source side of the radiation detector, and includes radiation absorbing members that are disposed at a predetermined spacing. The acquiring unit acquires an inclination angle of the grid, with respect to an array direction of the pixels, with which a spatial frequency of moiré fringes generated by the absorbing members in a captured radiographic image will be equal to or greater than a predetermined spatial frequency. The processor executes predetermined processing for making a relative angle between the grid and the radiation detector the acquired inclination angle.

Abstract: Provided are sensors and methods for detecting thermal neutrons. Provided is an apparatus having a scintillator for absorbing a neutron, the scintillator having a back side for discharging a scintillation light of a first wavelength in response to the absorbed neutron, an array of wavelength-shifting fibers proximate to the back side of the scintillator for shifting the scintillation light of the first wavelength to light of a second wavelength, the wavelength-shifting fibers being disposed in a two-dimensional pattern and defining a plurality of scattering plane pixels where the wavelength-shifting fibers overlap, a plurality of photomultiplier tubes, in coded optical communication with the wavelength-shifting fibers, for converting the light of the second wavelength to an electronic signal, and a processor for processing the electronic signal to identify one of the plurality of scattering plane pixels as indicative of a position within the scintillator where the neutron was absorbed.

Abstract: Scintillator materials based on mixed garnet compositions, as well as corresponding methods and systems, are described.

Abstract: Systems and methods for determining fluid mobility in rock samples using time-lapse position emission particle tracking.

Abstract: Apparatus and methods for imaging sources of gamma rays with a large area, comparatively low-cost Compton telescope (20). The Compton telescope (20) uses multiple layers (24) of low-cost organic solid plastic or liquid scintillator, arranged in large arrays of identical scintillator pixels (28). Photodiodes, avalanche photodiodes (30), or solid-state photomultipliers are used to read out the fluorescent pulses from scintillator pixels (28). Multiple scintillator pixels (28) are multiplexed into a few fast digitizers (80) and a few fast FPGA programmable digital microprocessors (78). Selection rule methods are presented for processing multiple near-simultaneous gamma ray collisions within the Compton telescope (28) to identify trackable events that yield gamma ray image data of interest. A calibration method achieves improved energy resolution along with (x,y) position information in pixels (28) made of organic scintillator materials with multiple photodetectors (30).

Abstract: Embodiments of the present disclosure provide for radionuclide probes, methods of using the radionuclide probes, methods of detecting an optical signal from radionuclides, methods of detecting an optical signal from a quantum dot(s) that receives optical energy from a radionuclide(s), system for analyzing optical energy emitted by a radionuclide(s), system for imaging a target within a living subject or a sample, methods of imaging a disease or condition, and the like.

Abstract: A neutron image detection method is disclosed, which collects a fluorescent light generated by a neutron incident at a designated position interval in one-dimensional geometry and determines an incident position of the neutron by detecting the collected fluorescent light, in which the fluorescent light is detected by a photon counting method; a pulse signal generated by an individual output photon is extracted on the basis of a clock signal generated with the same time interval as the time width of the pulse signal generated by a single photon; a count-value distribution is obtained in terms of incident position as variable determined by a single neutron incident by counting the pulse signal output; and a neutron incident position is determined by calculating a median point on the basis of the obtained count-value distribution.

Abstract: Signals generated by radiation sensors can be encoded to reduce the number of cables needed to transport information from a nuclear imaging apparatus to a processor for reconstruction. For example, signals from 16 radiation sensors can be encoded into three signals: T (top), L (left), and E (energy). This method of encoding signals can be capable of substantially reducing the number of signals, thereby reducing costs. In addition, reducing the number of signals could improve system timing performance by eliminating cable time-skew and facilitate the filter design by downgrading the circuit accuracy requirements such as group-delay error and filter signal skews.

Abstract: Embodiments of sensor systems and related methods of operating and manufacturing the same are described herein. The sensor systems can be used to detect atomic or subatomic particles or radiation. Other embodiments and related methods are also disclosed herein.

Abstract: A method and system for reducing scintillator afterglow. Methods for reducing afterglow include conditioning a scintillator by exposing it to high flux densities of ionizing radiation. One technique includes operating an x-ray tube at elevated amperage.

Abstract: Disclosed is a device for detecting orientation of a radioactive material to determine presence and position of the radioactive material, comprising: at least one first radiation detector; at least one second radiation detector, each of said at least one second radiation detector and each of said at least one first radiation detector being arranged side by side and in pairs, detection surfaces of said first and second radiation detector being in the same plane to receive radiation from the same direction in the same manner and to generate a first detection signal and a second detection signal, respectively; a shielding plate, said shielding plate being arranged between said first radiation detector and said second radiation detector arranged in a pair and extending forward beyond said detection surfaces; and a determination device for receiving the first and second detection signals from said first and second radiation detector, and determining whether a radioactive material exists or not according to said fi

Abstract: In a combined system, a magnetic resonance (MR) scanner includes a magnet configured to generate a static magnetic field at least in a MR examination region from which MR data are acquired. Radiation detectors are configured to detect gamma rays generated by positron-electron annihilation events in a positron emission tomography (PET) examination region. The radiation detectors include electron multiplier elements having a direction of electron acceleration arranged substantially parallel or anti-parallel with the static magnetic field. In some embodiments, the magnet is an open magnet having first and second spaced apart magnet pole pieces disposed on opposite sides of a magnetic resonance examination region, and the radiation detectors include first and second arrays of radiation detectors disposed with the first and second spaced apart magnet pole pieces.

Abstract: According to one aspect, a fluence monitoring detector for use with a multileaf collimator on a radiotherapy machine having an x-ray radiation source. The fluence monitoring detector includes a plurality of scintillating optical fibers, each scintillating optical fiber configured to generate a light output at each end thereof in response to incident radiation pattern thereon from the radiation source and multileaf collimator, a plurality of collection optical fibers coupled to the opposing ends of the scintillating optical fibers and operable to collect the light output coming from both ends of each scintillating optical fiber, and a photo-detector coupled to the collection optical fibers and operable to converts optical energy transmitted by the collection optical fibers to electric signals for determining actual radiation pattern information.

Abstract: In one embodiment, a neutron detector includes a three dimensional matrix, having nanocomposite materials and a substantially transparent film material for suspending the nanocomposite materials, a detector coupled to the three dimensional matrix adapted for detecting a change in the nanocomposite materials, and an analyzer coupled to the detector adapted for analyzing the change detected by the detector. In another embodiment, a method for detecting neutrons includes receiving radiation from a source, converting neutrons in the radiation into alpha particles using converter material, converting the alpha particles into photons using quantum dot emitters, detecting the photons, and analyzing the photons to determine neutrons in the radiation.

Abstract: A gamma ray detector having a scintillator with segments allows for a linearity calibration of the gamma ray detector without the use of a linearity phantom. The segments in the scintillator are configured to channel output radiation received by the gamma ray detector to loci identifiable in image data generated by photomultiplier tubes. The non-linearity in the detector system may be characterized, and a correction map may be generated, based upon the identifiable loci.

Abstract: A method of imaging a region of interest (ROI) in an object, the ROI having an axial extent greater than an axial FOV of a PET scanner. The method includes determining a number of overlapping scans of the PET scanner necessary to image at least the axial extent of the ROI, wherein each scan has a same axial length equal to the axial FOV, and each scan overlaps an adjacent scan by a predetermined overlap percentage of the axial length of each scan. Further, the method includes determining a total amount of excess scanning length of the scans based on the number, the axial extent of the ROI, and the axial FOV, and determining a new overlap percentage based on the total amount of excess scanning length and the predetermined overlap percentage, so that a new total amount of excess scanning length, as determined with the new overlap percentage, is zero.

Abstract: A method of locating a thermal updraft. In one embodiment, the method includes the steps of flying an aircraft in a flight path; making ionization measurements at a plurality of locations along the aircraft flight path using an ionization measuring device to measure ionization rate; determining in response to the ionization measurements areas of increased ionization rate; and denoting areas of increased ionization rate as areas of thermal updraft. In another embodiment, the method includes the steps of measuring ionizing radiation at each location along the aircraft flight path; and if ionizing radiation levels are above a predetermined value, determining that the location is within a thermal updraft and if the ionizing radiation levels are below a predetermined value, determining that the location is outside of a thermal updraft.

Abstract: A gamma-ray spectrometer comprising a scintillation body (34) for receiving gamma-rays and generating photons therefrom and a photodetector for detecting photons from the scintillation body and generating a corresponding output signal is described. The photodetector comprises a photocathode (26), an anode (28), and a reflecting surface (28A). The photocathode is arranged to receive photons from the source and generate photo-electrons therefrom. The anode is arranged to receive photoelectrons generated at the photocathode and is coupled to a detection circuit/amplifier configured to generate an output signal indicative of the photoelectrons received at the anode. The reflecting surface is arranged so as to reflect photons which have passed through the photocathode without interaction back towards the photocathode to provide the photons with another opportunity to interact with the photocathode, thus enhancing the overall effective quantum efficiency of the detector. The reflector may be specular or diffuse.

Abstract: This invention relates to a device for determining the conversion power of conversion element, a method for performing these measurements and a method for producing pcLEDs with essentially the same color point applying said device and said method.

Abstract: A ?-radiation detection system that includes at least one semiconductor detector such as HPGe-Detector, a position-sensitive ?-Detector, a TOF Controller, and a Digitizer/Integrator. The Digitizer/Integrator starts to process the energy signals of a ?-radiation sent from the HPGe-Detector instantly when the HPGe-Detector detects the ?-radiation. Subsequently, it is determined whether a coincidence exists between the ?-particles and ?-radiation signal, based on a determination of the time-of-flight of neutrons obtained from the ?-Detector and the HPGe-Detector. If it is determined that the time-of-flight falls within a predetermined coincidence window, the Digitizer/Integrator is allowed to continue and complete the energy signal processing. If, however, there is no coincidence, the Digitizer/Integrator is instructed to be clear and reset its operation instantly.

Abstract: A time-to-digital converter device includes a first delay chain circuit that generates a first value corresponding to a time delay between a start signal and a stop signal. The time-to-digital converter device also includes at least one second delay chain circuits that generates a second value corresponding to a time delay between a delayed start signal and the stop signal. At least one delay element generates the delayed start signal by applying a predetermined delay to the start signal, and a combining circuit generates an output value based on the first and second values. In the time-to-digital converter according to the exemplary embodiments of the present advancements, the output value corresponds to the time delay between the start signal and the stop signal.

Abstract: Methods, systems, and computer-readable mediums are provided that determine the angular orientation of detectors and detector electronic assemblies (“DEAs”). In various embodiments, the orientation of detectors/DEAs (in the ring) is determined with respect to other detectors/DEAs in the ring, the orientation of the detectors/DEAs with respect to a patient bed, or the orientation of the detectors/DEAs with respect to Earth's gravitational field. In another embodiment, a nuclear medical imaging system has one or more detector units arranged around or that can be swept around a patient bed. Each of the detector units includes an angular orientation-sensing accelerometer. By determining angular orientation of the detector from signals outputted by the accelerometer, the circumferential position of the detector relative to the patient bed can be determined. That information is used in conjunction with information about detected events to construct an image of an organ or tissue mass of interest.

Abstract: A liquid scintillator detector for three-dimensional dosimetric measurement of a radiation beam is provided wherein a volumetric phantom liquid scintillator is exposed to the radiation beam to produce light that is captured by the cameras that provide a three-dimensional image of the beam.

Abstract: A device having: a scintillator material, an optically transparent element containing a glass or polymer and gadolinium oxide, and one or more photomultiplier tubes adjacent to the scintillator material. The optically transparent element is surrounded by the scintillator material.

Abstract: A highly scalable platform for radiation measurement data collection with high precision time stamping and time measurements between the elements in the detection array uses IEEE 1588 with or without Synchronous Ethernet (timing over Ethernet) to synchronize the measurements. At a minimum, the system includes at least two radiation detector units, an IEEE 1588 and SyncE enabled Ethernet switch, and a computer for processing. The addition of timing over Ethernet and power over Ethernet (PoE) allows a radiation measurement system to operate with a single Ethernet cable, simplifying deployment of detectors using standardized technology with a multitude of configuration possibilities. This eliminates the need for an additional hardware for the timing measurements which simplifies the detection system, reduces the cost of the deployment, reduces the power consumption of the detection system and reduces the overall size of the system.

Abstract: A positron emission scanner is disclosed having a timing compensation element which uses position information originating from a spatial locator element to compensate for travel time of timing signals. A method of constructing a PET image is also discussed in which a timing error function is convolved with an envelope function evaluated along a line of response to derive an emission event weight for use in image construction.

Abstract: A scintillator radiation detector system according to one embodiment includes a scintillator; and a processing device for processing pulse traces corresponding to light pulses from the scintillator, wherein pulse digitization is used to improve energy resolution of the system. A scintillator radiation detector system according to another embodiment includes a processing device for fitting digitized scintillation waveforms to an algorithm based on identifying rise and decay times and performing a direct integration of fit parameters. A method according to yet another embodiment includes processing pulse traces corresponding to light pulses from a scintillator, wherein pulse digitization is used to improve energy resolution of the system. A method in a further embodiment includes fitting digitized scintillation waveforms to an algorithm based on identifying rise and decay times; and performing a direct integration of fit parameters. Additional systems and methods are also presented.

Abstract: A positron annihilation characteristics measurement system 10 comprises a positron source; radiation detection means 14 for detecting radiation emitted when a positron generated by the positron source is annihilated; and a positron detector 40 that detects a positron that is not injected into a measured sample S after being generated by the positron source. The positron source is disposed between the measured sample S and the positron detector. An arithmetic device 50 calculates the annihilation characteristics of the positron in the measured sample S after eliminating the radiation that is detected by the radiation detection means 14 and is expected to be emitted when the positron detected by the positron detector 40 is annihilated.

Abstract: A radiographic image capture device includes a wavelength conversion layer that converts radiation that has passed through an imaging subject into visible light, a first photodetector that detects the converted visible light and that converts the converted visible light into a first image signal expressing a radiographic image, a second photodetector that detects the converted visible light and that converts the converted visible light into a second image signal expressing a radiographic image, and a synthesizing section that combines the first image signal read from the first photodetector and the second image signal read from the second photodetector such that misalignment between the first and the second photodetectors is eliminated.

Abstract: A multi-modality cancer screening and diagnosis system is provided that allows cancer screening and diagnosis of a patient using at least two different and sequential three-dimensional imaging techniques without patient repositioning. The system includes a first three-dimensional image acquisition device, a second three-dimensional image acquisition device having a probe with a transmitter mounted thereon, and a positioning paddle for positioning and immobilizing an object to be imaged during the cancer screening and diagnosis procedure. The positioning paddle is designed to facilitate visualization of the breast in both three-dimensional modalities without movement of the patient, and preferably is designed to position the patient with comfort during a diagnosis procedure which uses both imaging modalities.

Abstract: A variable delay device is connected to a photosensor of a time-of-flight gamma ray detection system and includes a substrate on which a plurality of conductive pins are affixed. A first terminal connected to a first of the plurality of pins and a second terminal connected to the second of the plurality of pins are also affixed to the substrate. A jumper electrically connects the plurality of pins at a predetermined distance relative to the substrate, and a time delay of the variable delay device is determined based on the electrical path between the first and second terminals formed by the plurality of pins and the jumper.

Abstract: A method for estimating a line or response in a positron emission tomography scanner having depth of interaction estimation capability. The method utilizes information from both detector modules detecting a coincident event. A joint probability density function combining factors accounting for intermediate Compton scattering interactions and/or a final interaction that may be either a Compton scattering interaction or photoelectric absorption is calculated. In a preferred embodiment, a Bayesian estimation scheme is used to integrate the PDF for all permutations of the measured signal pairs, and the permutation with the largest joint probability is selected to construct the estimated line of response.

Abstract: The invention is directed to methods and arrangements for spatial acquisition of measurement data over the cross section of a bundle of high-energy, high-intensity radiation. The object of finding a novel possibility for radiation measurement within the cross section of a beam bundle of high intensity which acquires highly spatially resolved measurement data without impairment of the measuring accuracy through saturation or degradation of the detectors is met according to the invention in that the entire cross section of the beam bundle is imaged on a shading element, the cross section is separated successively into partial beam bundles having reduced cross section and reduced intensity through movement of at least one opening, and measurement values of the partial beam bundles passing the opening are acquired so as to be associated temporally and spatially with the positions of the opening and are stored.

Abstract: The present invention relates to a system and method for compensating for anode gain non-uniformity in a Multi-anode Position Sensitive Photomultiplier Tube (PS-PMT), in which a compensation unit is disposed between the multi-anode position sensitive photomultiplier tube and a position detection circuit unit and configured to uniform a current signal inputted to the position detection circuit unit, thereby compensating for anode gain non-uniformity. In accordance with the present invention, the compensation unit for changing resistance is used. Accordingly, there is an advantage in that the gain non-uniformity of each of the anodes of the PS-PMT can be compensated for. Furthermore, the gain non-uniformity of each of the anodes of the PS-PMT is compensated for by changing resistance values of the variable resistances of the compensation unit. Accordingly, there is an advantage in that the interaction positions of gamma rays can be calculated more precisely.

Abstract: An omni-directional sensor device is provided for detecting radiation emission sources, such as nuclear and atomic weapons and dirty bombs. The omni-directional sensor device is constructed as a three-dimensional structure formed of a plurality of walls of gamma ray detector arrays. The walls face in multiple directions to establish omni-directional sensing of incident gamma rays from substantially all directions. As constructed, a first wall of the device intercepts an incident gamma ray at a first location. The gamma ray experiences a Compton scattering effect whereby a deflected gamma ray is emitted into the inner chamber of the device before intercepting a second wall of the device at a second location. The first and second locations can be used to trace the location of the emission source. Also provided are radiation detection systems including the omni-directional sensor devices, and methods of locating a radiation emission source.