With Or Including A Luminophor Patents (Class 250/361R)
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Patent number: 6143200Abstract: When each of a rare earth oxysulfide phosphor represented by the composition formula (I) of Ln.sub.2 O.sub.2 S:xRe, yM wherein Ln represents at least one rare earth element selected from Y, La and Gd; Re represents at least one rare earth element selected from Pr and Tb; M represents at least one element selected from Nb, Ta and Mn; and x and y are numbers which satisfy the conditions of 1.times.10.sup.-4 .ltoreq.x.ltoreq.0.2 and 0.01 ppm .ltoreq.y.ltoreq.1000 ppm, respectively, and a rare earth oxysulfide phosphor represented by the composition formula (II) of (Gd .sub.1-x-y-z, Pr.sub.x, Sc.sub.y, Ce.sub.z).sub.2 O.sub.2 S wherein x, y and z are numbers which satisfy the conditions of 10.sup.-4 .ltoreq.x.ltoreq.2.times.10.sup.-1, 10.sup.-4 .ltoreq.y.ltoreq.10.sup.-1 and 0.ltoreq.z.ltoreq.10.sup.-6, respectively is excited by radiation, each of them emits a scintillation at high efficiency, and decreases the afterglow.Type: GrantFiled: December 10, 1998Date of Patent: November 7, 2000Assignee: Kasei Optonix, Ltd.Inventors: Takeshi Akiwa, Yuji Aoki, Etsuo Shimizu, Hideo Suzuki
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Patent number: 6100530Abstract: An angular time-synchronized directional radiation sensor is provided to indicate the direction, or distribution of directions, of incident gamma radiation, and consequently, to locate sources of radioactivity emitting these photons. The angular time-synchronized directional radiation sensor comprises a rotating radiation sensing means, interacting with the incident radiation to produce light flashes, together with a stationary photomultiplier tube that converts the light flashes to electrical pulses that are counted by a data collection means. A synchronous motor enables the radiation sensing means to complete a 360.degree. scan within 1 second to reduce the time needed for measuring from hours to only a few minutes. The data collection means calculates an angle of rotation at a corresponding fraction of the 360.degree. scan to rapidly indicate the direction of a radiation source. In one embodiment, the data collection means is a computer. The radiation sensing means can be a scintillator assembly.Type: GrantFiled: November 23, 1998Date of Patent: August 8, 2000Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Stanley Kronenberg, George J. Brucker
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Patent number: 6091796Abstract: A scintillation based microscope. One surface of a single crystal salt crystal scintillator is supported on an optically transparent support plate. The opposite surface, an illumination surface, of the crystal is coated with an optically reflecting material which is transparent to high energy photons (such as x-ray and/or high energy ultraviolet photons) in order to provide a scintillation sandwich having an optical mirror at the illumination surface of the crystal. These high energy photons are directed through a target to create a shadow image of the target on the illumination surface of the scintillator salt crystal. A portion or all of the shadow image is viewed with an optical device such as an eye piece to provide a very high resolution image of the target or portions of the target. In a preferred embodiment an adjustable pin hole unit is described to produce a very small x-ray spot source for producing high resolution geometric magnification of the shadow image of the target.Type: GrantFiled: October 28, 1996Date of Patent: July 18, 2000Assignee: Thermotrex CorporationInventors: Richard Trissel, Steve Horton, Brett Spivey, Lee Morsell
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Patent number: 6087666Abstract: An optically-stimulated luminescent radiation dosimeter system for the ree monitoring of radiation sources is disclosed. The system includes a radiation-sensitive optically-stimulated dosimeter which utilizes a new, doped glass material disposed at a remote location for storing energy from ionizing radiation when exposed thereto and for releasing the stored energy in the form of optically-stimulated luminescent light at a first wavelength when stimulated by exposure to light energy at a stimulating second wavelength.Type: GrantFiled: February 18, 1998Date of Patent: July 11, 2000Assignee: The United States of America as represented by the Secretary of the NavyInventors: Alan L. Huston, Brian L. Justus
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Patent number: 5973328Abstract: An neutron detector composed of fissionable material having ions of lithium, uranium, thorium, plutonium, or neptunium, contained within a glass film fabricated using a sol-gel method combined with a particle detector is disclosed. When the glass film is bombarded with neutrons, the fissionable material emits fission particles and electrons. Prompt emitting activated elements yielding a high energy electron contained within a sol-gel glass film in combination with a particle detector is also disclosed. The emissions resulting from neutron bombardment can then be detected using standard UV and particle detection methods well known in the art, such as microchannel plates, channeltrons, and silicon avalanche photodiodes.Type: GrantFiled: October 29, 1997Date of Patent: October 26, 1999Assignee: Lockheed Martin Energy Research CorporationInventors: John M. Hiller, Steven A. Wallace, Sheng Dai
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Patent number: 5962855Abstract: A radiation detector assembly employing an enlarged volume scintillation element and a photomultiplier tube. The scintillation element is surrounded by a reflective material and may be enclosed within a rigid shield for protection against shock and/or humidity. A Sidewall Axial Restraint and Compliance Assembly (SARCA) is positioned radially outside the reflective tape. Radial springs are placed outside the SARCA to provide stiff restraint in the axial and radial directions, The SARCA and springs provide for thermal expansion of the element. A two-stage axial biasing means is positioned at an end of the element, and an optical window may be positioned at the other end. Non-cylindrical portions may be formed along the circumference of the element. These non-cylindrical portions enable a larger element to be placed within the shield. In an alternative embodiment, the element is positioned apart from the photomultiplier tube with no window therebetween.Type: GrantFiled: February 25, 1998Date of Patent: October 5, 1999Assignee: General Electric Co.Inventors: Larry David Frederick, Larry David Frederick, Jr.
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Patent number: 5952665Abstract: A composite phosphor screen for converting radiation, such as X-rays, into visible light. The screen includes a planar surface, which can be formed from glass, silicon or metal, which has etched therein a multiplicity of closely spaced nanochannels having diameters of the order of 5 microns or less. Deposited within each of the nanochannels is a multiplicity of nanocrystalline phosphors, having diameters of less than 100 nanometers and preferably less than 10 nanometers, which emit light when acted upon by radiation. The walls of the nanochannels are arranged to reflect the light emitted by the nanophoshors down the nanochannels to suitable light collecting device such as film or an electronic device. This minimizes light scattering and increases light collection efficiency.Type: GrantFiled: November 28, 1997Date of Patent: September 14, 1999Assignee: Nanocrystals Technology L.P.Inventor: Rameshwar Nath Bhargava
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Patent number: 5923037Abstract: In a device for determining the ozone concentration by utilizing the surface chemiluminescence effect having a fan (13), a chemiluminescence element (8), a photomultiplier (6), a temperature sensor (16), and control electronics (12), an airflow generated by a fan (13) passes via a suction pipe (7) and an adjoining light trap system (17) through a venturi-shaped channel structure (2) along a metal block (9) in which a temperature sensor (16) is housed. The device is calibrated with respect to the temperature dependence of the reaction of a chemiluminescence disc (8) attached to the bottom of the metal block by determining the output voltage of a photomultiplier (6) in dependence on the temperature at a predetermined ozone concentration in the measured air.Type: GrantFiled: November 17, 1997Date of Patent: July 13, 1999Assignee: Deutsche Forschungsanstalt fur Luft-und Raumfahrt E.V.Inventors: Rainer Stager, Gerd Uhlemann, Reinhold Busen, Hans Gusten, Anthony Delany
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Patent number: 5905262Abstract: Radiation measuring apparatus includes a sensor assembly (10) including a sensor (16) which includes a scintillating body (30, 30') that absorbs radiation to be sensed and converts it to light. A measuring device (38) measures the intensity of the light emitted by the scintillating body and thereby indicates the amount of radiation to which the body (30) has been exposed. The sensor assembly may also include an optical fiber (12) by which the light emitted by the scintillating body is conducted to the measuring device (38). A plug (14) located on an end of the optical fiber remote from the sensor (16) is adapted to be detachably inserted in a connecting socket (40) of the measuring device (38). In this way the sensor assembly (10) is readily exchangeable for a new assembly.Type: GrantFiled: February 26, 1997Date of Patent: May 18, 1999Inventor: Keith Albert Spanswick
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Patent number: 5892230Abstract: A scintillating fiducial pattern, and methods of fabricating and using same, on a substrate or a resist/substrate composite, where the scintillating fiducial pattern is used in a spatial referencing scheme. The invention includes the use of a scintillating fiducial pattern as alignment or reference marks on a resist/substrate composite, into which a pattern or feature is to be defined. The invention includes the use of a scintillating fiducial in a mask alignment scheme. The invention includes the use of a scintillating fiducial grid or grating in conjunction with an energy beam locating method, or spatial-phase-locked electron-beam lithography. Spatial referencing to the scintillating fiducial grid, or grating, may be implemented with a delay-locked loop, which locks the phase of a signal from the scintillating grid, or grating, to the phase of a known signal.Type: GrantFiled: May 29, 1997Date of Patent: April 6, 1999Assignee: Massachusetts Institute of TechnologyInventors: James G. Goodberlet, Henry I. Smith
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Patent number: 5869836Abstract: A scintillation detector (10) includes a scintillation crystal (14) and a shock absorbing member (76) circumscribing the crystal (14). A sleeve (98) circumscribes the shock absorbing member (76) which, in turn, is circumscribed by a housing (12). The sleeve (98) provides for substantial controlled radial loading on the crystal (14). A method of manufacturing the detector (10) includes placing the crystal (14) and shock absorbing member (76) into the sleeve (98), compressing the sleeve 98 and inserting the compressed sleeve (98) into the housing (12) such that the sleeve (98) substantially maintains its compression. The radial stiffness causes vibration induced counts to occur at an excitation frequency which is above the operational bandwidth of the radiation measurements, thereby excluding vibration induced counts for radiation measurements.Type: GrantFiled: July 18, 1997Date of Patent: February 9, 1999Assignee: Saint-Gobain Industrial Ceramics, Inc.Inventors: Chris W. Linden, Jeffrey R. Lutz, William D. Sekela
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Patent number: 5796108Abstract: The invention is based in part on the discovery that a plastic housing that is lightweight is surprisingly efficient inasmuch as background signals from any gamma radiation are significantly reduced by using a plastic housing instead of a metal housing. A further aspect of the present invention is the profile of the housing as a bi-linear approximation to a parabola resulting in full optical response from any location on the scintillation material to the photomultiplier tube. A yet further aspect of the present invention is that the survey probe is resistant to magnetic fields. A yet further aspect of the present invention is the use of a snap-fit retaining bracket that overcomes the need for multiple screws.Type: GrantFiled: September 30, 1996Date of Patent: August 18, 1998Assignee: Battelle Memorial InstituteInventors: Dale M. Fleming, Kevin L. Simmons, Thomas J. Froelich, Gregory L. Carter
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Patent number: 5796109Abstract: A unitized scintillation detector, employing a scintillation element and a photomultiplier tube housed within inner and outer housings for protection against shock, and a scintillation shock assembly. The scintillation element is encased within potting material, which is enclosed within a rigid shield. A reflective coating or tape may be used to optimize light impulse transmission from the element to the photomultiplier. The element is further protected from shock by an elastomeric boot disposed around the shield and within the housing. Elastomeric material cushions the element on one end and a spring system protects the other end. The spring system is pre-loaded against the shield, not the element. Dual windows interfacing the scintillation element and photomultiplier tube at the other end of the element create an hermetic seal. The photomultiplier tube is encased within an elastomer with outwardly directed projections.Type: GrantFiled: March 12, 1997Date of Patent: August 18, 1998Assignee: Frederick Energy ProductsInventors: Larry D. Frederick, Larry D. Frederick, Jr.
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Patent number: 5783828Abstract: The present invention relates to an apparatus and a method for measuring tritium specific activity by gas scintillation. The specific activity is measured when the tritium is mixed in carrier streams of certain gases which serve as scintillation detection media. The apparatus comprises a detection chamber with connections for gaseous inlet and outlet, the detection chamber being optically connectable to at least one UV photomultiplier tube, which tube is connectable to means for measuring photon emittance.Type: GrantFiled: December 2, 1996Date of Patent: July 21, 1998Assignee: European Atomic Energy Community (EURATOM)Inventors: Paolo Pacenti, Fabrizio Campi, Cristina Mascherpa, Claudia Sterlini
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Patent number: 5753919Abstract: A gamma ray detector and measurement device having a generally elongate housing (11); a scintillator module (12) movably mounted in the housing (11) and arranged to respond to the presence of gamma rays in the local environment in which the device is located and which rays pass through the wall (13) of the housing and into the scintillator module, the module having an optical output (14) for transmitting an optical signal based on converted incoming gamma rays and an optical transducer module (15) also movably mounted in the housing (11) and having an input (16) arranged to receive the optical output from the scintillator module, the transducer module being able to convert the instantaneous optical output into an electrical output corresponding to the energy and flux of the incoming gamma radiation as detected in the scintillator module; in which the output (14) of the scintillator module (12) and the input of the transducer module (15) are closely spaced to each other, and define a space (17) therebetween toType: GrantFiled: March 13, 1997Date of Patent: May 19, 1998Assignee: Geolink (UK) LimitedInventors: Kenneth A. Prain, John H. Knight
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Patent number: 5742057Abstract: A unitized scintillation detector, employing a scintillation element and a photomultiplier tube housed within inner and outer housings for protection against shock, and a scintillation shock assembly. The scintillation element is encased within potting material, which is further enclosed within a rigid shield. A reflective coating or reflective tape may be used to optimize light impulse transmission from the element to the photomultiplier. The element is further protected from shock by an elastomeric boot disposed around the shield and within the housing. In addition, elastomeric material cushions the element on one end and a spring system protects the other end. The spring system is pre-loaded against the shield, not the element. Dual windows interfacing the scintillation element and photomultiplier tube at the other end of the element create an hermetic seal. In another embodiment, a single optical window may be used.Type: GrantFiled: May 3, 1996Date of Patent: April 21, 1998Assignee: Frederick Energy ProductsInventors: Larry D. Frederick, Larry David Frederick, Jr.
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Patent number: 5705818Abstract: A method of monitoring for radioactive contamination of scrap contained in a railroad car comprises the steps of detecting the presence of a moving railroad car. The railroad car is scanned for radioactive contamination upon being detected, and scanning continues thereafter. The identification of the railroad car is then determined by an RFID system. The scintillator scanning for radiation is deactivated when the vehicle is no longer detected. Once scanning is completed, then a determination is made whether the scanned vehicle is contaminated with radiation, and an indication that the vehicle is contaminated is made in that event.Type: GrantFiled: February 29, 1996Date of Patent: January 6, 1998Assignee: Bethlehem Steel CorporationInventors: Clinton J. Kelbel, Floyd A. Johnston
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Patent number: 5665970Abstract: A radiation sensor and/or imager is formed by sandwiching two materials having different atomic numbers (Z) around a radiation detector, such as scintilator or Geiger-Mueller type radiation counters, or solid state radiation detectors, such as those made of silicon). In one embodiment of the present invention, a thin layer of lead (Pb) is placed on one side of a Geiger-Mueller radiation counter and a layer of Lucite.TM. is disposed on the opposite side. One example, of a preferred Geiger-Mueller counter which may be used in the present invention is a modified pancake Geiger-Mueller counter with thin ruby mica windows, approximately 2.8 mg/cm.sup.2 thick on both sides.Type: GrantFiled: July 3, 1996Date of Patent: September 9, 1997Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Stanley Kronenberg, George J. Brucker
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Patent number: 5665971Abstract: A nuclear or x-ray detector which utilizes Compton double-scattering of photons by radiation particles, followed by photoelectron absorption, to reconstruct the energy and direction of such particles.Type: GrantFiled: August 8, 1995Date of Patent: September 9, 1997Assignee: Massachusetts Institute of TechnologyInventors: Min Chen, Alexander I. Bolozdynya
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Patent number: 5656817Abstract: Apparatus for detecting the presence, in aqueous media, of substances which emit alpha and/or beta radiation and determining the oxidation state of these radioactive substances, that is, whether they are in cationic or anionic form. In one embodiment, a sensor assembly has two elements, one comprised of an ion-exchange material which binds cations and the other comprised of an ion-exchange material which binds anions. Each ion-exchange element is further comprised of a scintillation plastic and a photocurrent generator. When a radioactive substance to which the sensor is exposed binds to either element and emits alpha or beta particles, photons produced in the scintillation plastic illuminate the photocurrent generator of that element. Sensing apparatus senses generator output and thereby indicates whether cationic species or anionic species or both are present and also provides an indication of species quantity.Type: GrantFiled: February 28, 1996Date of Patent: August 12, 1997Assignee: The Reents of the University of CaliforniaInventors: Kenneth E. Bower, Donald R. Weeks
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Patent number: 5640017Abstract: Device for the remote detection of radiation.This device has an optical fibre (4), a detecting crystal (10), whereof one end is optically coupled to the optical fibre and which is able to emit, by interacting with the radiation (2), a light which then propagates in the optical fibre, as well as an optical cladding (12) surrounding the detecting crystal and which is in optical contact therewith and whose optical index is lower than that of the detecting crystal, so as to confine said light by total reflection. Application to dosimetry.Type: GrantFiled: April 13, 1995Date of Patent: June 17, 1997Assignee: Commissariat a l'Energie AtomiqueInventor: Jean-Claude Thevenin
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Patent number: 5640016Abstract: A scintillator is disclosed that comprises a ceramic of a rare-earth oxysulfide activated with Pr, such as Gd.sub.2 O.sub.2 S:Pr, having: (1) a ratio of a peak value at about 270 K to that at about 140 K in a glow curve of about 0.01 or less, when the thermoluminescence intensity of the scintillator is measured at a rate of temperature increase of 15.+-.5 K/min after 20 minutes irradiation with ultraviolet rays having a wavelength of 254 nm and a power of 1 W/m.sup.2 at liquid nitrogen temperature, and (2) a ratio of a peak value at about 630 nm to that at about 512 nm of a thermoluminescence of about 410 K with about 2 nm resolution of about 1 or less.Type: GrantFiled: January 31, 1996Date of Patent: June 17, 1997Assignee: Kabushiki Kaisha ToshibaInventors: Naotoshi Matsuda, Masaaki Tamatani, Miwa Okumura, Kazuto Yokota
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Patent number: 5635717Abstract: An apparatus for sensing and locating sources of ionizing radiation retained in a turnout in a body environment, including a hand-held probe and comprising a housing with a sensor circuit for outputting a response to interaction between the radiation and the sensor; a unit for processing signals from the sensor circuit; and an indicator responding to driving signals applied thereto by generating an audible or visual output. Said hand-held probe comprises at least one scintillating plastic optical fibre (2) connecting the sensing end to a light sensor (1).Type: GrantFiled: March 6, 1995Date of Patent: June 3, 1997Assignee: DimasonInventor: Gheorghe D. Popescu
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Patent number: 5610016Abstract: The invention provides an assay by which detection and/or quantitation of adenyl group-containing substances can be performed simply, with high sensitivity and high signal-to-noise ratio. In particular, the method provides an assay in which the chemiluminescence of a chemiluminescent substance, made by reacting a glyoxal derivative with an adenyl group in the substance to be detected/quantitated in the presence of a heteropolyacid or a heteropolyacid salt, is measured.Type: GrantFiled: March 30, 1995Date of Patent: March 11, 1997Assignee: Mochida Pharmaceutical Co., Ltd.Inventors: Naofumi Sato, Kamon Shirakawa
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Patent number: 5594250Abstract: Water equivalent of accumulated snow determination by measurement of secondary background cosmic radiation attenuation by the snowpack. By measuring the attentuation of 3-10 MeV secondary gamma radiation it is possible to determine the water equivalent of snowpack. The apparatus is designed to operate remotely to determine the water equivalent of snow in areas which are difficult or hazardous to access during winter, accumulate the data as a function of time and transmit, by means of an associated telemetry system, the accumulated data back to a central data collection point for analysis. The electronic circuitry is designed so that a battery pack can be used to supply power.Type: GrantFiled: April 3, 1995Date of Patent: January 14, 1997Inventor: Kenneth J. Condreva
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Patent number: 5568304Abstract: An optical receiver for modulated light includes an optical antenna (12) having fluorescent material (18) dispersed therein, and an optoelectrical demodulator (14) for demodulating the modulated light. The optical antenna (12) is formed of a filter material which is transparent to wavelengths equal to or longer than a predetermined wavelength and absorptive to wavelengths shorter than the predetermined wavelength. Also, the optical antenna (12) has a coating (20) of a filter material which is transparent to wavelengths equal to or shorter than the predetermined wavelength, and reflective to wavelengths longer than the predetermined wavelength. Thus, the optical antenna (12) acts on a narrow-pass band filter. Since the fluorescent material emits light at a longer wavelength than the received light, the emitted light is reflected internally to impact on the optoelectrical demodulator (14).Type: GrantFiled: June 6, 1995Date of Patent: October 22, 1996Assignee: AT&T Global Information Solutions CompanyInventor: Peter F. Baur
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Patent number: 5557107Abstract: A device locating radiation sources includes a pinhole camera, a collimator means for closing off or obturating the camera, a luminescent or phosphor screen, and a camera optically coupled to the screen. The collimator comprises two half-collimators rotatable about a common rotation axis (AA').Type: GrantFiled: March 13, 1995Date of Patent: September 17, 1996Assignee: Commissariat A L'Energie AtomiqueInventors: Hubert Carcreff, Gilles Thellier
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Patent number: 5517030Abstract: Detectors for ionizing radiation (X-rays, gamma rays, electrons, protons, alpha particles, etc. as well as neutrons) of the gas proportional scintillation counter type using techniques to compensate for a loss of scintillation light reaching the photosensor due to solid angle and reflection effects. Two such techniques are disclosed. One technique involves the use of two non-parallel electrically charged grids which produce a radially increasing electric field, thus radially increasing the intensity of the scintillation light. Another technique involves the use of a mask of small opaque dots having a radially decreasing density covering the photosensor, thus radially increasing the intensity of the scintillation light transmitted to the photosensor. The preferred embodiment for X-ray detection consists in a detector, filled with very pure xenon at atmospheric pressure, with a 2.5 cm diameter radiation window (1), a grid with a spherical (2 cm radius) curvature (2) with its edges placed 0.Type: GrantFiled: June 14, 1994Date of Patent: May 14, 1996Inventors: Carlos A. Nabais Conde, Joaquim Marques Ferreira dos Santos, Antonio C. Sena Sao Miguel Benito
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Patent number: 5512753Abstract: A scintillation counting system utilizing scintillator capsules for the detection of radioactive substances in a sample for analysis include a liquid scintillator core encapsulated within a shell. The liquid scintillator comprises a base component or components and one or more fluors. The base component preferably includes one or more aromatic solvents. The fluors useful in the liquid or gel scintillator include any of the organic fluors well-known in the scintillation counting art. The liquid or gel scintillator can also include a wavelength shifter (i.e. secondary fluors). Useful wavelength shifters are also well known in the scintillation counting art. Additionally, a other materials can be added to the scintillator capsules to modify the characteristics of the scintillator capsules, and the scintillator capsules can be used in a variety of scintillation counting applications.Type: GrantFiled: June 8, 1994Date of Patent: April 30, 1996Assignee: Packard Instrument, B.V.Inventors: James Thomson, Jan ter Wiel, Harry van Lune, Herbert M. Bosel, Gerhard H. Kremer
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Patent number: 5496502Abstract: An adhesive plastic scintillator which can be attached onto a solid support medium such as a microtiter plate, either by melting it in and/or on a solid support medium because the plastic scintillator is capable of being changed between solid and liquid phases, whichever is desired, by temperature control, or by deposition from a solution of said adhesive plastic scintillator. The plastic scintillator is for analyzing radioactive samples and comprises fluorescent substances and optionally energy transfer compounds for converting radiation energy into light energy. The plastic scintillator remains transparent upon transition from the liquid to the solid state, and upon the same transition adheres to the solid support medium.Type: GrantFiled: November 18, 1994Date of Patent: March 5, 1996Assignee: Packard Instrument, B.V.Inventor: James Thomson
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Patent number: 5493121Abstract: A method and apparatus for measuring radiation are disclosed in which a scintillation body intercepts incident radiation to cause the body to emit a population of scintillation photons, the population of scintillation photons is spectrally decomposed into at least a first subpopulation of photons and a second subpopulation of photons (the first subpopulation originating from faster time decay processes than the second subpopulation) and at least one of the subpopulations is detected.Type: GrantFiled: November 30, 1992Date of Patent: February 20, 1996Assignee: Optical Semiconductors, Inc.Inventor: Brian J. Fitzpatrick
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Patent number: 5479017Abstract: A radiation scanning mechanism is capable of increasing an observable range by eliminating a restriction on a scannable range of a conventional scanning mechanism for a radiation TV set for scanning an observation object by a directional radiation detector to display the distribution state of a radioactive material as an image. In the radiation scanning mechanism, an inner frame having a rotary shaft provided with a directional gamma-ray detector is attached to an outer frame having a rotary shaft so that the rotary shaft of the inner frame may perpendicularly and rotatably intersect the rotary shaft of the outer frame, and the rotary shaft of tile outer frame is rotatably supported by an outer frame support base.Type: GrantFiled: April 11, 1994Date of Patent: December 26, 1995Assignee: Doryokuro Kakunenryo Kaihatsu JigyodanInventors: Tadashi Yamada, Toshikatsu Sugaya, Yasushi Dounomae, Yoshio Kashimura
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Patent number: 5466930Abstract: A scintillator for absorbing and concentrating radioactive ions within a solution, the scintillator including a solid scintillator and an ionic layer on a surface of and in contact with the solid scintillator. When radioactive ions are absorbed by the ionic layer, the scintillator acts as a light source.Type: GrantFiled: February 23, 1994Date of Patent: November 14, 1995Assignee: Florida State UniversityInventor: Joseph B. Schlenoff
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Patent number: 5446286Abstract: An efficient and ultrafast sensor for X-ray and UV radiation based on doped nanocrystals. These doped nanocrystals consist preferably of impurity-activator doped wide band gap II-VI semiconductors. They yield high efficiency and short recombination time radiation-sensitive phosphors which in response to radiation emit visible light easily detected by conventional sensors such as Si sensors. The combination of pulsed UV/X-ray sources with efficient and ultrafast sensors will yield sensors with increased signal to noise ratio. In a preferred embodiment, thin films of doped nanocrystals are used for generating visible radiation, which can be imaged with a conventional Si-based camera. Other applications also include the use of doped nanocrystals of piezoelectric materials to sense pressure, of pyroelectric materials to sense heat, and of ferroelectric materials to sense electric fields.Type: GrantFiled: August 11, 1994Date of Patent: August 29, 1995Inventor: Rameshwar N. Bhargava
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Patent number: 5444251Abstract: The invention provides a method of detecting and monitoring ionizing radiation such as nuclear radiation. The method comprises providing a diamond radiation sensor element having a nitrogen concentration not exceeding 20 ppm and which is optimized for phosphorescent response, and exposing it to ionizing radiation. The resulting phosphorescent response of the sensor element is then monitored, typically over a period of at least 20 seconds. The invention extends to the sensor element itself, and to apparatus employing the sensor.Type: GrantFiled: March 2, 1994Date of Patent: August 22, 1995Inventors: Tom L. Nam, Shawn Araikum, Rex J. Keddy
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Patent number: 5430299Abstract: A PET radiation detector includes a pair of amplifying gaps 3,21 to enhance the electron yield from a TMAE gas, BaF.sub.2 gamma detector, together with a gate electrode 17 to inhibit passage of charge to the detector electrodes and reverse passage of ions to the crystal. A further reverse-biased gap may be positioned adjacent the crystal to prevent charge build-up thereon. Shield electrodes 23,25 prevent gate switching signals causing spurious responses in the detector circuit.Type: GrantFiled: April 12, 1994Date of Patent: July 4, 1995Assignee: British Technology Group Ltd.Inventors: James E. Bateman, Richard Stephenson
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Patent number: 5427950Abstract: A method of quantitative measurement of a very small amount of low-energy beta radioactivity in a biological sample, a process for preparing samples and a device therefore, which require no large-scaled equipment and no labor for sample preparation, measurement, correction of the measured values and treatment of waste solution after measurement. The method comprises: forming a solid, liquid or liquefied biological sample containing a radioactive substance so as to have a substantially uniform and predetermined thickness; freezing or solidifying the sample and measuring the radioactivity thereof.Type: GrantFiled: January 12, 1993Date of Patent: June 27, 1995Assignee: Kabushiki Kaisha Seitai Kagaku KankyushoInventors: Akiyo Shigematsu, Naomi Motoji, Yasuko Niikura, Yuko Shiina, Yasuhiko Hatori, Mitsunobu Okuyama
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Patent number: 5422075Abstract: The present invention relates to a chemical luminescence-detecting apparatus that is provided with a plurality of optical detectors different in sensitivity in the vicinity of a photometric cell. A ratio of outputs from the optical detectors based on intensity of luminescence is previously determined and stored. Signal processing can multiply an output of a low sensitivity optical detector by a factor determined by the stored ratio to measure the intensity of luminescence so that a conversion value corresponding to an equivalent output from a high sensitivity optical detector may be obtained when the output from the high sensitivity optical detector has become saturated.Type: GrantFiled: May 27, 1993Date of Patent: June 6, 1995Assignees: Sankyo Company, Limited, Horiba, Ltd.Inventors: Yukio Saito, Koichi Sekiya, Yoshihiro Sato, Takeshi Kohno, Hiroaki Takahasi, Kunio Terada, Takayuki Aoki
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Patent number: 5391876Abstract: Afterglow in a luminescent material in which a significant factor in afterglow is the release of holes from hole traps in the scintillator material is substantially reduced by adding cerium as a hole-trapping species to the scintillator composition which successfully competes with the hole traps in the basic scintillator composition. In gadolinium gallium garnet activated with chromium, the addition of cerium in the range of 0.2 to 0.255 weight percent reduces afterglow in this manner while exhibiting excellent stability to x-ray damage after exposure to an initial pair of x-ray pulses.Type: GrantFiled: May 27, 1994Date of Patent: February 21, 1995Assignee: General Electric CompanyInventors: Veneta G. Tsoukala, Charles D. Greskovich
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Patent number: 5360557Abstract: In a computed tomography machine employing a luminescent material in a scintillator in which a significant factor in afterglow is the release of holes from hole traps in the scintillator material, afterglow in the luminescent material is substantially reduced by adding a hole-trapping species to the scintillator composition which successfully competes with the hole traps in the basic scintillator composition. For a gadolinium gallium garnet scintillator activated with chromium, the addition of cerium reduces afterglow in this manner.Type: GrantFiled: February 28, 1994Date of Patent: November 1, 1994Assignee: General Electric CompanyInventors: Veneta G. Tsoukala, Charles D. Greskovich
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Patent number: 5336889Abstract: A gamma radiation detector and a radioluminiscent composition for use therein. The detector includes a radioluminscent composition that emits light in a characteristic wavelength region when exposed to gamma radiation, and means for detecting said radiation. The composition contains a scintillant such as anglesite (PbSO.sub.4) or cerussite (PbCO.sub.3) incorporated into an inert, porous glass matrix via a sol-gel process. Particles of radiation-sensitive scintillant are added to, a sol solution. The mixture is polymerized to form a gel, then dried under conditions that preserve the structural integrity and radiation sensitivity of the scintillant. The final product is a composition containing the uniformly-dispersed scintillant in an inert, optically transparent and highly porous matrix. The composition is chemically inert and substantially impervious to environmental conditions including changes in temperature, air pressure, and so forth.Type: GrantFiled: January 4, 1993Date of Patent: August 9, 1994Assignee: The United States of America as represented by the United States Department of EnergyInventor: Kenneth J. Hofstetter
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Patent number: 5334838Abstract: A radiation-sensing assembly adapted for sensing radiation emitted from a source of radiation which may be non-coal layers (shale and other materials) in a coal mine tunnel. The sensor assembly incudes a housing forming an enclosure for a radiation-sensing medium. A cover is provided on the top of the lower portion of the housing, and radiation passes through the cover to impinge on the sensing machine. The cover includes a collimator, which is built into the cover, to direct the radiation from the source to the sensing medium.Type: GrantFiled: December 11, 1992Date of Patent: August 2, 1994Assignee: American Mining Electronics, Inc.Inventor: John W. Ramsden, Jr.
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Patent number: 5332906Abstract: A scintillator assembly for use in conjunction with a photomultiplier or the like in the detection of alpha radiation utilizes a substrate or transparent yttrium aluminum garnet and a relatively thin film of cerium-doped yttrium aluminum garnet coated upon the substrate. The film material is applied to the substrate in a sputtering process, and the applied film and substrate are annealed to effect crystallization of the film upon the substrate. The resultant assembly provides relatively high energy resolution during use in a detection instrument and is sufficiently rugged for use in field environments.Type: GrantFiled: August 12, 1992Date of Patent: July 26, 1994Assignee: Martin Marietta Energy Systems, Inc.Inventors: Robert J. Lauf, Stephanie A. McElhaney, John B. Bates
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Patent number: 5321268Abstract: An undersea probe which can be attached to marine animals for collecting data as to light intensity and temperature in regions where the marine animals travel. The probe is essentially omnidirectional in its light acceptance capability so that light intensity measurements will not be dependent upon any particular orientation of the probe. The probe includes a central optical fiber containing a fluorescent dye enclosed in a transparent or translucent, protective and fouling-resistant sheath. The optical fiber is provided at its outer end with a fiber terminator which blocks entry of light into the end of the fiber. At its opposite inner end, the fiber is coupled to a light detector in a housing which may be implanted in the marine animal. The optical fiber exhibits radial changes in its refractive index to trap light which approaches the surface of the fiber from inside and which makes a small enough angle with that surface. Such light is propagated along the fiber to the light detector.Type: GrantFiled: February 22, 1993Date of Patent: June 14, 1994Assignee: Northwest Marine Technology, Inc.Inventors: David A. Crosby, Philip A. Ekstrom
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Patent number: 5313064Abstract: The present invention is a scintillator which emits light in response to radiation. The scintillator is capable of being reversibly changed between solid and liquid phases, whichever is desired, by temperature control. The scintillator comprises a fluorescent substance for converting radiation energy into light energy; a solvent which transfers radiation energy to the fluorescent substance and dissolves and diffuses the fluorescent substance and a radioactive substance acting as an object of measurement to thereby homogenize them; and a fixing substance which enables the solvent, the fluorescent substance and the radioactive substance to be fixed in a solid state and also liquified upon heating, the fixing substance being capable of phase change reversibility.Type: GrantFiled: August 7, 1992Date of Patent: May 17, 1994Assignee: Packard Instrument B.V.Inventor: Haruo Fujii
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Patent number: 5306445Abstract: The invention relates to a composition for the volumetric generation of radiation. The composition comprises a porous substrate loaded with a component capable of emitting radiation upon interaction with an exciting radiation. Preferably, the composition is an aerogel substrate loaded with a component, e.g., a phosphor, capable of interacting with exciting radiation of a first energy, e.g., ultraviolet light, to produce radiation of a second energy, e.g., visible light.Type: GrantFiled: May 18, 1992Date of Patent: April 26, 1994Assignee: The United States of America as represented by the United States Department of EnergyInventors: Scott Reed, Robert J. Walko, Carol S. Ashley, C. Jeffrey Brinker
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Patent number: 5283439Abstract: The scintillator uses a luminescent crystal (5) under the action of an ionizing radiation. It is particularly intended for use at high temperatures and accelerations. The crystal (5) is surrounded by PTFE powder (11) which is sintered cold and then conditioned hot and under pressure.Type: GrantFiled: January 19, 1993Date of Patent: February 1, 1994Assignee: Quartz Et SiliceInventors: Claude Bouissou, Claude Baron
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Patent number: 5281820Abstract: A detector for detecting invisible radiation and charged particles is composed of at least one radiation-absorbing panel and at least one optical waveguide arranged parallel to the surface of said panel and containing a fluorescent dyestuff. The luminescent light produced in the panel by the absorbed radiation is converted into a fluorescent radiation in the optical waveguide conducted to a photosensitive semiconductor component by total reflection and measured at that point.Type: GrantFiled: July 3, 1991Date of Patent: January 25, 1994Assignee: Hoechst AktiengesellschaftInventors: Werner Groh, Jochen Coutandin, Peter Herbrechtsmeier, Jurgen Theis, Thomas Stehlin
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Patent number: 5272348Abstract: Dose of radiation to which a body of crystalline material has been exposed is measured by exposing the body to optical radiation at a first wavelength, which is greater than about 540 nm, and measuring optical energy emitted from the body by luminescence at a second wavelength, which is longer than the first wavelength.Type: GrantFiled: June 28, 1991Date of Patent: December 21, 1993Assignee: Battelle Memorial InstituteInventor: Steven D. Miller
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Patent number: 5243193Abstract: A detection material for ionizing radiation. The material is solid at room temperature but meltable to a fluid at a temperature of about 100.degree. C. One essential component in said detection material is a low molecular weight aromatic polymer, preferably a thermoplastic resin that contains low molecular weight polymer molecules of styrene and/or styrene derivatives. The detection material optionally contains a hot melt polymer and a wax-like substance, such as paraffin.Type: GrantFiled: December 17, 1991Date of Patent: September 7, 1993Assignee: Wallac OyInventors: Jari Suontausta, Timo Oikari