Patents Assigned to Fisk University
  • Patent number: 9638809
    Abstract: 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: Grant
    Filed: August 7, 2014
    Date of Patent: May 2, 2017
    Assignees: Consolidated Nuclear Security, LLC, Fisk University
    Inventors: Ashley C. Stowe, Arnold Burger, Pijush Bhattacharya, Yevgeniy Tupitsyn
  • Patent number: 9638813
    Abstract: 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: Grant
    Filed: September 30, 2015
    Date of Patent: May 2, 2017
    Assignees: Consolidated Nuclear Security, LLC, Fisk University, University of Tennessee Research Foundation
    Inventors: Ashley Stowe, Arnold Burger, Eric Lukosi
  • Patent number: 9632190
    Abstract: 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: Grant
    Filed: March 31, 2014
    Date of Patent: April 25, 2017
    Assignees: Consolidates Nuclear Security, LLC, Fisk University
    Inventors: Ashley C. Stowe, Arnold Burger
  • Patent number: 9612345
    Abstract: 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: Grant
    Filed: September 2, 2015
    Date of Patent: April 4, 2017
    Assignees: Cosolidated Nuclear Security, LLC, Fisk University
    Inventors: Ashley C. Stowe, Arnold Burger
  • Publication number: 20170090045
    Abstract: 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: Application
    Filed: August 7, 2014
    Publication date: March 30, 2017
    Applicants: Consolidated Nuclear Security, LLC, Fisk University
    Inventors: Ashley C. STOWE, Arnold BURGER, Pijush BHATTACHARYA, Yevgeniy TUPITSYN
  • Publication number: 20160349383
    Abstract: 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: Application
    Filed: October 7, 2013
    Publication date: December 1, 2016
    Applicants: Fisk University, Lawrence Livermore National Security, LLC
    Inventors: Stephen A. Payne, Nerine J. Cherepy, Giulia E. Hull, Alexander D. Drobshoff, Arnold Burger
  • Patent number: 9441154
    Abstract: 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: Grant
    Filed: March 20, 2014
    Date of Patent: September 13, 2016
    Assignees: Lawrence Livermore National Security, LLC, Fisk University
    Inventors: Stephen A. Payne, Nerine Cherepy, Christian Pedrini, Arnold Burger
  • Patent number: 9429662
    Abstract: 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: Grant
    Filed: March 31, 2014
    Date of Patent: August 30, 2016
    Assignees: Consolidated Nuclear Security, LLC, Fisk University
    Inventors: Ashley C. Stowe, Arnold Burger, Michael Groza
  • Patent number: 9334581
    Abstract: 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: Grant
    Filed: October 23, 2012
    Date of Patent: May 10, 2016
    Assignees: Consolidated Nuclear Security, LLC, Fisk University
    Inventors: Ashley Stowe, Arnold Burger
  • Publication number: 20160041273
    Abstract: 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: Application
    Filed: August 7, 2014
    Publication date: February 11, 2016
    Applicants: Consolidated Nuclear Security, LLC, Fisk University
    Inventors: Ashley C. STOWE, Arnold BURGER, Pijush BHATTACHARYA, Yevgeniy TUPITSYN
  • Patent number: 8884228
    Abstract: 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: Grant
    Filed: January 27, 2012
    Date of Patent: November 11, 2014
    Assignees: Savannah River Nuclear Solutions, LLC, Fisk University
    Inventors: Aaron L. Washington, II, Martine C. Duff, Lucile C. Teague, Arnold Burger, Michael Groza
  • Publication number: 20140144373
    Abstract: 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: Application
    Filed: October 23, 2012
    Publication date: May 29, 2014
    Applicants: Fisk University, Babcock & Wilcox Technical Services Y-12, L.L.C., Attn: Mike Renner
    Inventors: Bacock & Wilcox Technical Services Y-12, L.L.C., Fisk University
  • Patent number: 8580149
    Abstract: 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: Grant
    Filed: October 21, 2008
    Date of Patent: November 12, 2013
    Assignees: Lawrence Livermore National Security, LLC, Fisk University
    Inventors: Stephen A. Payne, Nerine J. Cherepy, Giulia E. Hull, Alexander D. Drobshoff, Arnold Burger
  • Publication number: 20130193336
    Abstract: 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: Application
    Filed: January 27, 2012
    Publication date: August 1, 2013
    Applicants: Fisk University, Savannah River Nuclear Solutions, LLC
    Inventors: Aaron L. Washington, II, Martine C. Duff, Lucile C. Teague, Arnold Burger, Michael Groza
  • Patent number: 7687780
    Abstract: A semiconductor detector for ionizing electromagnetic radiation, neutrons, and energetic charged particles. The detecting element is comprised of a compound having the composition I-III-VI2 or II-IV-V2 where the “I” component is from column 1A or 1B of the periodic table, the “II” component is from column 2B, the “III” component is from column 3A, the “IV” component is from column 4A, the “V” component is from column 5A, and the “VI” component is from column 6A. The detecting element detects ionizing radiation by generating a signal proportional to the energy deposited in the element, and detects neutrons by virtue of the ionizing radiation emitted by one or more of the constituent materials subsequent to capture. The detector may contain more than one neutron-sensitive component.
    Type: Grant
    Filed: October 11, 2005
    Date of Patent: March 30, 2010
    Assignees: Babcock & Wilcox Technical Services Y-12, LLC, Fisk University
    Inventors: Zane W. Bell, Arnold Burger