Patents Assigned to Fisk University
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Patent number: 10024982Abstract: According to one embodiment, a scintillator includes a host material having the chemical formula: A2BX6, where A includes a monovalent ion, B includes a tetravalent ion, and X includes a halide ion.Type: GrantFiled: August 6, 2015Date of Patent: July 17, 2018Assignees: LAWRENCE LIVERMORE NATIONAL SECURITY, LLC, FISK UNIVERSITYInventors: Stephen A. Payne, Nerine Cherepy, Arnold Burger
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Patent number: 9658350Abstract: A radiation detection device, including: a support structure; and a chalcopyrite crystal coupled to the support structure; wherein, when the chalcopyrite crystal is exposed to radiation, a visible spectrum of the chalcopyrite crystal changes from an initial color to a modified color. The visible spectrum of the chalcopyrite crystal is changed back from the modified color to the initial color by annealing the chalcopyrite crystal at an elevated temperature below a melting point of the chalcopyrite crystal over time. The chalcopyrite crystal is optionally a 6LiInSe2 crystal. The radiation is comprised of neutrons that decrease the 6Li concentration of the chalcopyrite crystal via a 6Li(n,?) reaction. The initial color is yellow and the modified color is one of orange and red. The annealing temperature is between about 450 degrees C. and about 650 degrees C. and the annealing time is between about 12 hrs and about 36 hrs.Type: GrantFiled: June 3, 2015Date of Patent: May 23, 2017Assignees: CONSOLIDATED NUCLEAR SECURITY, LLC, FISK UNIVERSITYInventors: Ashley C. Stowe, Brenden Wiggins, Arnold Burger
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Patent number: 9638813Abstract: A combined thermal neutron detector and gamma-ray spectrometer system, including: a detection medium including a lithium chalcopyrite crystal operable for detecting thermal neutrons in a semiconductor mode and gamma-rays in a scintillator mode; and a photodetector coupled to the detection medium also operable for detecting the gamma rays. Optionally, the detection medium includes a 6LiInSe2 crystal. Optionally, the detection medium comprises a compound formed by the process of: melting a Group III element; adding a Group I element to the melted Group III element at a rate that allows the Group I and Group III elements to react thereby providing a single phase I-III compound; and adding a Group VI element to the single phase I-III compound and heating; wherein the Group I element includes lithium.Type: GrantFiled: September 30, 2015Date of Patent: May 2, 2017Assignees: Consolidated Nuclear Security, LLC, Fisk University, University of Tennessee Research FoundationInventors: Ashley Stowe, Arnold Burger, Eric Lukosi
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Patent number: 9638809Abstract: A combined thermal neutron detector and gamma-ray spectrometer system, including: a first detection medium including a lithium chalcopyrite crystal operable for detecting neutrons; a gamma ray shielding material disposed adjacent to the first detection medium; a second detection medium including one of a doped metal halide, an elpasolite, and a high Z semiconductor scintillator crystal operable for detecting gamma rays; a neutron shielding material disposed adjacent to the second detection medium; and a photodetector coupled to the second detection medium also operable for detecting the gamma rays; wherein the first detection medium and the second detection medium do not overlap in an orthogonal plane to a radiation flux. Optionally, the first detection medium includes a 6LiInSe2 crystal. Optionally, the second detection medium includes a SrI2(Eu) scintillation crystal.Type: GrantFiled: August 7, 2014Date of Patent: May 2, 2017Assignees: Consolidated Nuclear Security, LLC, Fisk UniversityInventors: Ashley C. Stowe, Arnold Burger, Pijush Bhattacharya, Yevgeniy Tupitsyn
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Patent number: 9632190Abstract: A neutron imaging system, including: a plurality of Li-III-VI2 semiconductor crystals arranged in an array, wherein III represents a Group III element and VI represents a Group VI element; and electronics operable for detecting and a charge in each of the plurality of crystals in the presence of neutrons and for imaging the neutrons. Each of the crystals is formed by: melting the Group III element; adding the Li to the melted Group III element at a rate that allows the Li and Group III element to react, thereby providing a single phase Li-III compound; and adding the Group VI element to the single phase Li-III compound and heating. Optionally, each of the crystals is also formed by doping with a Group IV element activator.Type: GrantFiled: March 31, 2014Date of Patent: April 25, 2017Assignees: Consolidates Nuclear Security, LLC, Fisk UniversityInventors: Ashley C. Stowe, Arnold Burger
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Patent number: 9612345Abstract: A photodetector device, including: a scintillator material operable for receiving incident radiation and emitting photons in response; a photodetector material coupled to the scintillator material operable for receiving the photons emitted by the scintillator material and generating a current in response, wherein the photodetector material includes a chalcopyrite semiconductor crystal; and a circuit coupled to the photodetector material operable for characterizing the incident radiation based on the current generated by the photodetector material. Optionally, the scintillator material includes a gamma scintillator material and the incident radiation received includes gamma rays. Optionally, the photodetector material is further operable for receiving thermal neutrons and generating a current in response. The circuit is further operable for characterizing the thermal neutrons based on the current generated by the photodetector material.Type: GrantFiled: September 2, 2015Date of Patent: April 4, 2017Assignees: Cosolidated Nuclear Security, LLC, Fisk UniversityInventors: Ashley C. Stowe, Arnold Burger
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Publication number: 20170090045Abstract: A combined thermal neutron detector and gamma-ray spectrometer system, including: a first detection medium including a lithium chalcopyrite crystal operable for detecting neutrons; a gamma ray shielding material disposed adjacent to the first detection medium; a second detection medium including one of a doped metal halide, an elpasolite, and a high Z semiconductor scintillator crystal operable for detecting gamma rays; a neutron shielding material disposed adjacent to the second detection medium; and a photodetector coupled to the second detection medium also operable for detecting the gamma rays; wherein the first detection medium and the second detection medium do not overlap in an orthogonal plane to a radiation flux. Optionally, the first detection medium includes a 6LiInSe2 crystal. Optionally, the second detection medium includes a SrI2(Eu) scintillation crystal.Type: ApplicationFiled: August 7, 2014Publication date: March 30, 2017Applicants: Consolidated Nuclear Security, LLC, Fisk UniversityInventors: Ashley C. STOWE, Arnold BURGER, Pijush BHATTACHARYA, Yevgeniy TUPITSYN
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Publication number: 20160349383Abstract: In one embodiment, a material comprises a crystal comprising strontium iodide providing at least 50,000 photons per MeV, where the strontium iodide material is characterized by a volume not less than 1 cm3. In another embodiment, a scintillator optic includes europium-doped strontium iodide providing at least 50,000 photons per MeV, where the europium in the crystal is primarily Eu2+, and the europium is present in an amount greater than about 1.6%. A scintillator radiation detector in yet another embodiment includes a scintillator optic comprising SrI2 and BaI2, where a ratio of SrI2 to BaI2 is in a range of between 0:1 and 1.0, the scintillator optic is a crystal that provides at least 50,000 scintillation photons per MeV and energy resolution of less than about 5% at 662 keV, and the crystal has a volume of 1 cm3 or more; the scintillator optic contains more than about 2% europium.Type: ApplicationFiled: October 7, 2013Publication date: December 1, 2016Applicants: Fisk University, Lawrence Livermore National Security, LLCInventors: Stephen A. Payne, Nerine J. Cherepy, Giulia E. Hull, Alexander D. Drobshoff, Arnold Burger
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Patent number: 9441154Abstract: In one embodiment, a crystal includes at least one metal halide; and an activator dopant comprising ytterbium. In another general embodiment, a scintillator optic includes: at least one metal halide doped with a plurality of activators, the plurality of activators comprising: a first activator comprising europium, and a second activator comprising ytterbium. In yet another general embodiment, a method for manufacturing a crystal suitable for use in a scintillator includes mixing one or more salts with a source of at least one dopant activator comprising ytterbium; heating the mixture above a melting point of the salt(s); and cooling the heated mixture to a temperature below the melting point of the salts. Additional materials, systems, and methods are presented.Type: GrantFiled: March 20, 2014Date of Patent: September 13, 2016Assignees: Lawrence Livermore National Security, LLC, Fisk UniversityInventors: Stephen A. Payne, Nerine Cherepy, Christian Pedrini, Arnold Burger
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Patent number: 9429662Abstract: A bulk semiconducting scintillator device, including: a Li-containing semiconductor compound of general composition Li-III-VI2, wherein III is a Group III element and VI is a Group VI element; wherein the Li-containing semiconductor compound is used in one or more of a first mode and a second mode, wherein: in the first mode, the Li-containing semiconductor compound is coupled to an electrical circuit under bias operable for measuring electron-hole pairs in the Li-containing semiconductor compound in the presence of neutrons and the Li-containing semiconductor compound is also coupled to current detection electronics operable for detecting a corresponding current in the Li-containing semiconductor compound; and, in the second mode, the Li-containing semiconductor compound is coupled to a photodetector operable for detecting photons generated in the Li-containing semiconductor compound in the presence of the neutrons.Type: GrantFiled: March 31, 2014Date of Patent: August 30, 2016Assignees: Consolidated Nuclear Security, LLC, Fisk UniversityInventors: Ashley C. Stowe, Arnold Burger, Michael Groza
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Publication number: 20160146953Abstract: A combined thermal neutron detector and gamma-ray spectrometer system, including: a detection medium including a lithium chalcopyrite crystal operable for detecting thermal neutrons in a semiconductor mode and gamma-rays in a scintillator mode; and a photodetector coupled to the detection medium also operable for detecting the gamma rays. Optionally, the detection medium includes a 6LiInSe2 crystal. Optionally, the detection medium comprises a compound formed by the process of: melting a Group III element; adding a Group I element to the melted Group III element at a rate that allows the Group I and Group III elements to react thereby providing a single phase I-III compound; and adding a Group VI element to the single phase I-III compound and heating; wherein the Group I element includes lithium.Type: ApplicationFiled: September 30, 2015Publication date: May 26, 2016Applicants: CONSOLIDATED NUCLEAR SECURITY, LLC, UNIVERSITY OF TENNESSEE RESEARCH FOUNDATION, FISK UNIVERSITYInventors: Ashley Stowe, Arnold Burger, Eric Lukosi
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Patent number: 9334581Abstract: A method for synthesizing I-III-VI2 compounds, including: melting a Group III element; adding a Group I element to the melted Group III element at a rate that allows the Group I and Group III elements to react thereby providing a single phase I-III compound; and adding a Group VI element to the single phase I-III compound under heat, with mixing, and/or via vapor transport. The Group III element is melted at a temperature of between about 200 degrees C. and about 700 degrees C. Preferably, the Group I element consists of a neutron absorber and the group III element consists of In or Ga. The Group VI element and the single phase I-III compound are heated to a temperature of between about 700 degrees C. and about 1000 degrees C. Preferably, the Group VI element consists of S, Se, or Te. Optionally, the method also includes doping with a Group IV element activator.Type: GrantFiled: October 23, 2012Date of Patent: May 10, 2016Assignees: Consolidated Nuclear Security, LLC, Fisk UniversityInventors: Ashley Stowe, Arnold Burger
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Publication number: 20160041273Abstract: A combined thermal neutron detector and gamma-ray spectrometer system, including: a first detection medium including a lithium chalcopyrite crystal operable for detecting neutrons; a gamma ray shielding material disposed adjacent to the first detection medium; a second detection medium including one of a doped metal halide, an elpasolite, and a high Z semiconductor scintillator crystal operable for detecting gamma rays; a neutron shielding material disposed adjacent to the second detection medium; and a photodetector coupled to the second detection medium also operable for detecting the gamma rays; wherein the first detection medium and the second detection medium do not overlap in an orthogonal plane to a radiation flux. Optionally, the first detection medium includes a 6LiInSe2 crystal. Optionally, the second detection medium includes a SrI2(Eu) scintillation crystal.Type: ApplicationFiled: August 7, 2014Publication date: February 11, 2016Applicants: Consolidated Nuclear Security, LLC, Fisk UniversityInventors: Ashley C. STOWE, Arnold BURGER, Pijush BHATTACHARYA, Yevgeniy TUPITSYN
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Publication number: 20150378031Abstract: A photodetector device, including: a scintillator material operable for receiving incident radiation and emitting photons in response; a photodetector material coupled to the scintillator material operable for receiving the photons emitted by the scintillator material and generating a current in response, wherein the photodetector material includes a chalcopyrite semiconductor crystal; and a circuit coupled to the photodetector material operable for characterizing the incident radiation based on the current generated by the photodetector material. Optionally, the scintillator material includes a gamma scintillator material and the incident radiation received includes gamma rays. Optionally, the photodetector material is further operable for receiving thermal neutrons and generating a current in response. The circuit is further operable for characterizing the thermal neutrons based on the current generated by the photodetector material.Type: ApplicationFiled: September 2, 2015Publication date: December 31, 2015Applicants: FISK UNIVERSITY, CONSOLIDATED NUCLEAR SECURITY, LLCInventors: Ashley C. STOWE, Arnold BURGER
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Publication number: 20150285924Abstract: A radiation detection device, including: a support structure; and a chalcopyrite crystal coupled to the support structure; wherein, when the chalcopyrite crystal is exposed to radiation, a visible spectrum of the chalcopyrite crystal changes from an initial color to a modified color. The visible spectrum of the chalcopyrite crystal is changed back from the modified color to the initial color by annealing the chalcopyrite crystal at an elevated temperature below a melting point of the chalcopyrite crystal over time. The chalcopyrite crystal is optionally a 6LiInSe2 crystal. The radiation is comprised of neutrons that decrease the 6Li concentration of the chalcopyrite crystal via a 6Li(n,?) reaction. The initial color is yellow and the modified color is one of orange and red. The annealing temperature is between about 450 degrees C. and about 650 degrees C. and the annealing time is between about 12 hrs and about 36 hrs.Type: ApplicationFiled: June 3, 2015Publication date: October 8, 2015Applicants: FISK UNIVERSITY, CONSOLIDATED NUCLEAR SECURITY, LLCInventors: Ashley C. STOWE, Brenden WIGGINS, Arnold BURGER
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Publication number: 20140361221Abstract: In one embodiment, a crystal includes at least one metal halide; and an activator dopant comprising ytterbium. In another general embodiment, a scintillator optic includes: at least one metal halide doped with a plurality of activators, the plurality of activators comprising: a first activator comprising europium, and a second activator comprising ytterbium. In yet another general embodiment, a method for manufacturing a crystal suitable for use in a scintillator includes mixing one or more salts with a source of at least one dopant activator comprising ytterbium; heating the mixture above a melting point of the salt(s); and cooling the heated mixture to a temperature below the melting point of the salts. Additional materials, systems, and methods are presented.Type: ApplicationFiled: March 20, 2014Publication date: December 11, 2014Applicants: FISK UNIVERSITY, Lawrence Livermore National Security, LLCInventors: Stephen A. Payne, Nerine Cherepy, Christian Pedrini, Arnold Burger
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Patent number: 8884228Abstract: An apparatus and process is provided to illustrate the manipulation of the internal electric field of CZT using multiple wavelength light illumination on the crystal surface at RT. The control of the internal electric field is shown through the polarization in the IR transmission image under illumination as a result of the Pockels effect.Type: GrantFiled: January 27, 2012Date of Patent: November 11, 2014Assignees: Savannah River Nuclear Solutions, LLC, Fisk UniversityInventors: Aaron L. Washington, II, Martine C. Duff, Lucile C. Teague, Arnold Burger, Michael Groza
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Publication number: 20140209805Abstract: A bulk semiconducting scintillator device, including: a Li-containing semiconductor compound of general composition Li-III-VI2, wherein III is a Group III element and VI is a Group VI element; wherein the Li-containing semiconductor compound is used in one or more of a first mode and a second mode, wherein: in the first mode, the Li-containing semiconductor compound is coupled to an electrical circuit under bias operable for measuring electron-hole pairs in the Li-containing semiconductor compound in the presence of neutrons and the Li-containing semiconductor compound is also coupled to current detection electronics operable for detecting a corresponding current in the Li-containing semiconductor compound; and, in the second mode, the Li-containing semiconductor compound is coupled to a photodetector operable for detecting photons generated in the Li-containing semiconductor compound in the presence of the neutrons.Type: ApplicationFiled: March 31, 2014Publication date: July 31, 2014Applicants: FISK UNIVERSITY, BABCOCK & WILCOX TECHNICAL SERVICES Y-12, L.L.C.Inventors: Ashley C. Stowe, Arnold Burger, Michael Groza
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Publication number: 20140144373Abstract: A method for synthesizing I-III-VI2 compounds, including: melting a Group III element; adding a Group I element to the melted Group III element at a rate that allows the Group I and Group III elements to react thereby providing a single phase I-III compound; and adding a Group VI element to the single phase I-III compound under heat, with mixing, and/or via vapor transport. The Group III element is melted at a temperature of between about 200 degrees C. and about 700 degrees C. Preferably, the Group I element consists of a neutron absorber and the group III element consists of In or Ga. The Group VI element and the single phase I-III compound are heated to a temperature of between about 700 degrees C. and about 1000 degrees C. Preferably, the Group VI element consists of S, Se, or Te. Optionally, the method also includes doping with a Group IV element activator.Type: ApplicationFiled: October 23, 2012Publication date: May 29, 2014Applicants: Fisk University, Babcock & Wilcox Technical Services Y-12, L.L.C., Attn: Mike RennerInventors: Bacock & Wilcox Technical Services Y-12, L.L.C., Fisk University
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Patent number: 8580149Abstract: In one embodiment, a material comprises a crystal comprising strontium iodide providing at least 50,000 photons per MeV. A scintillator radiation detector according to another embodiment includes a scintillator optic comprising europium-doped strontium iodide providing at least 50,000 photons per MeV. A scintillator radiation detector in yet another embodiment includes a scintillator optic comprising SrI2 and BaI2, wherein a ratio of SrI2 to BaI2 is in a range of between 0:1 A method for manufacturing a crystal suitable for use in a scintillator includes mixing strontium iodide-containing crystals with a source of Eu2+, heating the mixture above a melting point of the strontium iodide-containing crystals, and cooling the heated mixture near the seed crystal for growing a crystal. Additional materials, systems, and methods are presented.Type: GrantFiled: October 21, 2008Date of Patent: November 12, 2013Assignees: Lawrence Livermore National Security, LLC, Fisk UniversityInventors: Stephen A. Payne, Nerine J. Cherepy, Giulia E. Hull, Alexander D. Drobshoff, Arnold Burger