Patent•
Apparatus for detecting the location of incident radiation
29 Sep 1980-
TL;DR: In this article, an apparatus for detecting the location of incident radiation comprises at least one pair of assembly comprised of a scintillation crystal consisting of a plurality of crystal segments, and a pair of photo-multiplier tubes optically coupled to the crystal so as to be able to detect scintillations produced in any one of these crystal segments.
Abstract: An apparatus for a detecting the location of incident radiation comprises at least one pair of assembly comprised of a scintillation crystal consisting of a plurality of crystal segments, a pair of photo-multiplier tubes optically coupled to the scintillation crystal so as to be able to detect a scintillation produced in any one of these crystal segments. These plural crystal segments are coupled to each other in such manner that any scintillation produced in any single crystal segment will cause the photo-multiplier tubes to deliver substantially a same output irrespective of the illuminating position within this crystal segment, and also that scintillations produced in the respective crystal segments will cause the photo-multiplier tubes to deliver outputs which are different in level for the respective crystal segments.
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Patent•
07 Nov 1985
TL;DR: In this paper, a two-dimensional photon position encoder system was proposed, which included a detector for enhancing the spatial resolution of the situs of the origin of incident photons of gamma rays, and the statistical distribution of these photoelectrons was processed by an improved pattern recognition technique such that the positioning information can be determined.
Abstract: A two-dimensional photon position encoder system (10) and process which includes a detector (20) for enhancing the spatial resolution of the situs of the origin of incident photons of gamma rays. A plurality of scintillator material members (22) interact with the incident photons and produce a quantifiable number of photons which exit the scintillation material members. A tuned light guide (68) having a plurality of radiation barriers (92) of predetermined lengths define slots which are operatively associated with one of the scintillator material members. These slots (90) serve to enhance the predictability of the statistical distribution of photons along the length of the slotted light guide (68). A detector (20) detects the distribution of the photons at preselected locations along the length of the slotted light guide. In one embodiment, this detector (20) comprises a photomultiplier (70) which gathers information concerning the photoelectrons which are then counted. The statistical distribution of these photoelectrons is processed by an improved pattern recognition technique such that the positioning information can be determined.
72 citations
Patent•
24 May 1984
TL;DR: In this paper, a positron emission tomography camera has a plurality of detector rings positioned side-by-side or offset by one-half of the detector cross section around a patient area to detect radiation therefrom.
Abstract: A positron emission tomography camera having a plurality of detector rings positioned side-by-side or offset by one-half of the detector cross section around a patient area to detect radiation therefrom. Each ring contains a plurality of scintillation detectors which are positioned around an inner circumference with a septum ring extending inwardly from the inner circumference along each outer edge of each ring. An additional septum ring is positioned in the middle of each ring of detectors and parallel to the other septa rings whereby the inward extent of all the septa rings may be reduced by one-half and the number of detectors required in each ring is reduced. Each detector ring or offset ring includes a plurality of photomultiplier tubes and a plurality of scintillation crystals are positioned relative to the photomultiplier tubes whereby each tube is responsive to more than one crystal. Each alternate crystal in the ring is offset by one-half or less of the thickness of the crystal such that the staggered crystals are seen by more than one photomultiplier tube. This sharing of crystals and photomultiplier tubes allows identification of the staggered crystal and the use of smaller detectors shared by larger photomultiplier tubes thereby requiring less photomultiplier tubes, creating more scanning slices, providing better data sampling, and reducing the cost of the camera. The offset detector ring geometry combined with the additional septa reduces the cost of the positron camera and improves its performance.
48 citations
Patent•
10 Dec 1990TL;DR: In this article, a radiation detector comprising a scintillator array for emitting scintillation light upon incidence of radiation to a scinterator and distributing the scinterillation light to the other scinterceptors at a predetermined distribution ratio and plural photomultiplier tubes optically coupled to the array for converting the scitter light into an amplified electrical signal representing an incident position of the radiation to the scintilator array.
Abstract: A radiation detector comprising a scintillator array for emitting scintillation light upon incidence of radiation to a scintillator and distributing the scintillation light to the other scintillators at a predetermined distribution ratio and plural photomultiplier tubes optically coupled to the scintillator array for converting the scintillation light into an amplified electrical signal representing an incident position of the radiation to the scintillator array. The scintillator array comprises plural scintillators, and each pair of neighboring scintillators have coupling surface on both of confronting surfaces thereof for optically coupling the neighboring scintillators therethrough, each of the coupling surfaces having at least one of a roughened surface and a mirror-polished surface having different transmissivities to light passing therethrough to thereby adjust the distribution ratio of the scintillation light transmitted from one of the scintillators to another.
48 citations
Patent•
21 Aug 1985
TL;DR: In this paper, a radioisotope camera with an array of scintillation crystals arranged in N rows and M columns and adapted to be struck by gamma-rays from a subject, a separate solid state photodetector (15 ) optically coupled to each crystal, and N+M amplifiers (24) connected to the photodeteectors (15) to distinguish the particular row and column of an activated photodeterector.
Abstract: A radioisotope camera (10) having an array (12) of scintillation crystals (13) arranged in N rows and M columns and adapted to be struck by gamma-rays from a subject, a separate solid state photodetector (15 ) optically coupled to each crystal (13), and N+M amplifiers (24) connected to the photodetectors (15) to distinguish the particular row and column of an activated photodetector. One of the anode or cathode leads (33 or 34) of each photodetector (15) is coupled to the row amplifier (24) associated with the row containing that photodetector while the other of the two leads (34 or 33) is coupled to the column amplifier (24) associated with the column containing that photodetector.
39 citations
Patent•
19 Nov 2002TL;DR: In this article, a method, system and a radiation detector system for use therein are provided for determining the depth distribution of radiation-emitting material distributed in a source medium, such as a contaminated field, without the need to take samples of extensive soil samples.
Abstract: A method, system and a radiation detector system for use therein are provided for determining the depth distribution of radiation-emitting material distributed in a source medium, such as a contaminated field, without the need to take samples, such as extensive soil samples, to determine the depth distribution. The system includes a portable detector assembly with an x-ray or gamma-ray detector having a detector axis for detecting the emitted radiation. The radiation may be naturally-emitted by the material, such as gamma-ray-emitting radionuclides, or emitted when the material is struck by other radiation. The assembly also includes a hollow collimator in which the detector is positioned. The collimator causes the emitted radiation to bend toward the detector as rays parallel to the detector axis of the detector. The collimator may be a hollow cylinder positioned so that its central axis is perpendicular to the upper surface of the large area source when positioned thereon. The collimator allows the detector to angularly sample the emitted radiation over many ranges of polar angles. This is done by forming the collimator as a single adjustable collimator or a set of collimator pieces having various possible configurations when connected together. In any one configuration, the collimator allows the detector to detect only the radiation emitted from a selected range of polar angles measured from the detector axis. Adjustment of the collimator or the detector therein enables the detector to detect radiation emitted from a different range of polar angles. The system further includes a signal processor for processing the signals from the detector wherein signals obtained from different ranges of polar angles are processed together to obtain a reconstruction of the radiation-emitting material as a function of depth, assuming, but not limited to, a spatially-uniform depth distribution of the material within each layer. The detector system includes detectors having different properties (sensitivity, energy resolution) which are combined so that excellent spectral information may be obtained along with good determinations of the radiation field as a function of position.
36 citations
References
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Patent•
13 Aug 1973
TL;DR: In this paper, a scintillation counting apparatus is provided which measures scintillations arising from both beta and gamma radiation, which can also be used solely as a gamma detecting instrument.
Abstract: In the measurement of radiation by means of scintillation counters one drawback has been the scarcity of radiation counters which efficiently measure both gamma and beta radiation. There has also been the problem of scintillation counting in the face of external or background radiation. A scintillation counting apparatus is provided herein which measures scintillations arising from both beta and gamma radiation. The apparatus also effects a better separation of sample radiation from background radiation. The apparatus can also be used solely as a gamma detecting instrument. In such apparatus a radioactive sample, is placed in a housing coupled to a photomultiplier. In this apparatus the housing itself is an inorganic phosphor.
28 citations
Patent•
12 May 1981
TL;DR: In this article, a high-resolution radioactivity distribution detection system with a plurality of crystal assemblies that are disposed in rows and columns and define a sensing array is presented. But the system is not suitable for high-dimensional data.
Abstract: A crystal detector array, particularly for a high resolution radioactivity distribution detection system, with a plurality of crystal assemblies that are disposed in rows and columns and define a sensing array. Each crystal assembly is provided with four sensing heads. Each head is a quadrant of the crystal assembly and is identified by a unique address location in the array. A plurality of detectors are superimposed on the sensing array. Certain ones of the detectors are in registration with one sensing head of four crystal assemblies in adjacent rows and columns. Radioactive events emitted from a subject under diagnosis activate selected ones of the sensing heads. Light signals generated by the activated heads are detected by the detectors and processed to provide a presentation of radioactivity distribution within the subject under diagnosis.
7 citations
Patent•
09 Mar 1971
TL;DR: In this paper, a series of RECTANGULAR WAFERS have been used to form a cyclone-like structure in a room, where the cyclone is detected at the end of the room by means of photo-visual sensors.
Abstract: A SCINTILLATION CRYSTAL INCLUDING A SERIES OF RECTANGULAR WAFERS HAVING THEIR ADJACENT FACES ADHERED TO ONE ANOTHER WITH OPTICAL ADHESIVE TO FORM A BAR. RADIATION IS RECEIVED THROUGH A SIDE OF THE CRYSTAL BAR. SCINTILLATIONS IN THE CRYSTAL ARE DETECTED AT THE ENDS OF THE BAR BY MEANS OF PHOTOSENSITIVE DEVICES.
3 citations