Patents by Inventor Zewu Chen
Zewu Chen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
-
Patent number: 7298817Abstract: An x-ray fluorescence technique for detecting the level of arsenic in a sample of water or body fluid. Arsenic and lead are expected to fluoresce in a first energy band and lead is expected to also fluoresce separately in a second energy band. An excitation path directs x-rays toward the sample; a first detection path detects x-ray fluorescence of the first energy band from the sample; and a second detection path detects x-ray fluorescence of the second energy band from the sample. The level of arsenic can be obtained by analyzing the x-ray fluorescence from both detection paths, and using a constant which relates the level of lead in the second energy band to the level of lead in the first energy band. The excitation path and each detection path may each include a monochromating optic to transmit the desired x-ray energy band, e.g., a doubly curved optic.Type: GrantFiled: November 30, 2004Date of Patent: November 20, 2007Assignee: X-ray Optical Systems, Inc.Inventors: Zewu Chen, Walter M. Gibson
-
Publication number: 20070140420Abstract: An x-ray source assembly and method of operation are provided having enhanced output stability. The assembly includes an anode having a source spot upon which electrons impinge and a control system for controlling position of the anode source spot relative to an output structure. The control system can maintain the anode source spot location relative to the output structure notwithstanding a change in one or more operating conditions of the x-ray source assembly. One aspect of the disclosed invention is most amenable to the analysis of sulfur in petroleum-based fuels.Type: ApplicationFiled: February 8, 2007Publication date: June 21, 2007Applicant: X-RAY OPTICAL SYSTEMS, INC.Inventors: Ian Radley, Thomas Bievenue, John Burdett, Brian Gallagher, Stuart Shakshober, Zewu Chen, Michael Moore
-
Patent number: 7209545Abstract: An x-ray source assembly (2700) and method of operation are provided having enhanced output stability. The assembly includes an anode (2125) having a source spot upon which electrons (2120) impinge and a control system (2715/2720) for controlling position of the anode source spot relative to an output structure. The control system can maintain the anode source spot location relative to the output structure (2710) notwithstanding a change in one or more operating conditions of the x-ray source assembly. One aspect of the disclosed invention is most amenable to the analysis of sulfur in petroleum-based fuels.Type: GrantFiled: June 3, 2004Date of Patent: April 24, 2007Assignee: X-Ray Optical Systems, Inc.Inventors: Ian Radley, Thomas J. Bievenue, John H. Burdett, Jr., Brian W. Gallagher, Stuart M. Shakshober, Zewu Chen, Michael D. Moore
-
Patent number: 7206375Abstract: Compact, low-power-consuming systems and methods for exposing samples to high-energy radiation, for example, for exposing samples to x-rays for implementing x-ray absorption near edge analysis (XANES). The systems and methods include a low-power-consuming radiation source, such as an x-ray tube; one or more tunable crystal optics for directing and varying the energy of the radiation onto a sample under analysis; and a radiation detecting device, such as an x-ray detector, for detecting radiation emitted by the sample. The one or more tunable crystal optics may be doubly-curved crystal optics. The components of the system may be arranged in a collinear fashion. The disclosed systems and methods are particularly applicable to XANES analysis, for example, XANES analysis of the chemical state of chromium or another transition metal in biological processes.Type: GrantFiled: December 1, 2005Date of Patent: April 17, 2007Assignee: X-Ray Optical Systems, Inc.Inventors: Zewu Chen, Walter Gibson
-
Patent number: 7110506Abstract: A method and device for cooling and electrically-insulating a high-voltage, heat-generating component, for example, an x-ray tube (1105) for analyzing fluids by means of x-ray fluorescence. The device includes an x-ray source (1100) including an x-ray tube (1105) having improved heat-dissipating properties due to the thermal coupling of the x-ray tube with a thermally-conductive, dielectric material (1150). The device may include a base assembly (1135) mounted to the component for conducting heat away from the component while electrically isolating the component. In one aspect of the invention, the base assembly includes two copper plates (1140, 1145) separated by a dielectric plate (1150). The dielectric plate minimizes or prevents the leakage of current through the base assembly (1135). One aspect of the disclosed invention is most amenable to the analysis of sulfur in petroleum-based fuels.Type: GrantFiled: June 3, 2004Date of Patent: September 19, 2006Assignee: X-Ray Optical Systems, Inc.Inventors: Ian Radley, Thomas J. Bievenue, John H. Burdett, Jr., Brian W. Gallagher, Stuart M. Shakshober, Zewu Chen
-
Publication number: 20060193440Abstract: A method and device for cooling and electrically-insulating a high-voltage, heat-generating component, for example, an x-ray tube (1105) for analyzing fluids by means of x-ray fluorescence. The device includes an x-ray source (1100) including an x-ray tube (1105) having improved heat-dissipating properties due to the thermal coupling of the x-ray tube with a thermally-conductive, dielectric material (1150). The device may include a base assembly (1135) mounted to the component for conducting heat away from the component while electrically isolating the component. In one aspect of the invention, the base assembly includes two copper plates (1140, 1145) separated by a dielectric plate (1150). The dielectric plate minimizes or prevents the leakage of current through the base assembly (1135). One aspect of the disclosed invention is most amenable to the analysis of sulfur in petroleum-based fuels.Type: ApplicationFiled: April 14, 2006Publication date: August 31, 2006Applicant: X-Ray Optical Systems, Inc.Inventors: Ian Radley, Thomas Bievenue, John Burdett, Brian Gallagher, Stuart Shakshober, Zewu Chen
-
Patent number: 7072439Abstract: A technique for analyzing fluids by means of x-ray fluorescence applicable to any fluid, including liquids and gases, which emit x-ray fluorescence when exposed to x-rays. The apparatus includes an x-ray source (82) including an x-ray tube (64) having improved heat dissipating properties due to a thermally-conductive, dielectric material (70, 1150). The x-ray tube also includes means for aligning (100, 2150, 2715) the tube with the source housing whereby the orientation of the x-ray beam produced by the source can be optimized, and stabilized over various operating conditions. The method and apparatus may also include an x-ray detector having a small-area, for example, a PIN-diode type semiconductor x-ray detector (120), that can provide effective x-ray detection at room temperature. One aspect of the disclosed invention is most amenable to the analysis of sulfur in petroleum-based fuels.Type: GrantFiled: June 1, 2004Date of Patent: July 4, 2006Assignee: X-Ray Optical Systems, Inc.Inventors: Ian Radley, Thomas J. Bievenue, John H. Burdett, Jr., Brian W. Gallagher, Stuart M. Shakshober, Zewu Chen, Michael D. Moore
-
Publication number: 20060120508Abstract: Compact, low-power-consuming systems and methods for exposing samples to high-energy radiation, for example, for exposing samples to x-rays for implementing x-ray absorption near edge analysis (XANES). The systems and methods include a low-power-consuming radiation source, such as an x-ray tube; one or more tunable crystal optics for directing and varying the energy of the radiation onto a sample under analysis; and a radiation detecting device, such as an x-ray detector, for detecting radiation emitted by the sample. The one or more tunable crystal optics may be doubly-curved crystal optics. The components of the system may be arranged in a collinear fashion. The disclosed systems and methods are particularly applicable to XANES analysis, for example, XANES analysis of the chemical state of chromium or another transition metal in biological processes.Type: ApplicationFiled: December 1, 2005Publication date: June 8, 2006Applicant: X-Ray Optical Systems, Inc.Inventors: Zewu Chen, Walter Gibson
-
Patent number: 7035374Abstract: Devices for improving the capturing and utilization of high-energy electromagnetic radiation, for example, x-rays, gamma rays, and neutrons, for use in physical, medical, and industrial analysis and control applications are disclosed. The devices include optics having a plurality of optical crystals, for example, doubly-curved silicon or germanium crystals, arranged to optimize the capture and redirection of divergent radiation via Bragg diffraction. In one aspect, a plurality of optic crystals having varying atomic diffraction plane orientations are used to capture and focus divergent x-rays upon a target. In another aspect, a two- or three-dimensional matrix of crystals is positioned relative to an x-ray source to capture and focus divergent x-rays in three dimensions.Type: GrantFiled: February 1, 2005Date of Patent: April 25, 2006Assignee: X-Ray Optical Systems, Inc.Inventor: Zewu Chen
-
Patent number: 7023955Abstract: Measurement technique and apparatus for examining a region of a patterned surface such as an integrated circuit (IC). Excitation x-ray, neutron, particle-beam or gamma ray radiation is directed toward a two-dimensional sample area of the IC. Emissions (e.g., x-ray fluorescence—XRF) from the sample area are detected. A mask is placed in a planar radiation path formed by the source, detector and the sample area, and in one embodiment moveable relative to the sample area. The mask includes an elongate aperture to substantially confine the excitation radiation directed to the sample area, and the emissions from the sample area, to the planar radiation path when arranged parallel to a first axis of the two-dimensional sample area. The invention allows predictive measurement of feature characteristics in active circuit regions of the IC, using sample areas outside of these regions.Type: GrantFiled: August 12, 2003Date of Patent: April 4, 2006Assignee: X-Ray Optical System, Inc.Inventors: Zewu Chen, Shinichi Terada
-
Publication number: 20050201517Abstract: Devices for improving the capturing and utilization of high-energy electromagnetic radiation, for example, x-rays, gamma rays, and neutrons, for use in physical, medical, and industrial analysis and control applications are disclosed. The devices include optics having a plurality of optical crystals, for example, doubly-curved silicon or germanium crystals, arranged to optimize the capture and redirection of divergent radiation via Bragg diffraction. In one aspect, a plurality of optic crystals having varying atomic diffraction plane orientations are used to capture and focus divergent x-rays upon a target. In another aspect, a two- or three-dimensional matrix of crystals is positioned relative to an x-ray source to capture and focus divergent x-rays in three dimensions.Type: ApplicationFiled: February 1, 2005Publication date: September 15, 2005Applicant: X-Ray Optical Systems, Inc.Inventor: Zewu Chen
-
Patent number: 6934359Abstract: X-ray fluorescence (XRF) spectroscopy systems and methods are provided. One system includes a source of x-ray radiation and an excitation optic disposed between the x-ray radiation source and the sample for collecting x-ray radiation from the source and focusing the x-ray radiation to a focal point on the sample to incite at least one analyte in the sample to fluoresce. The system further includes an x-ray fluorescence detector and a collection optic comprising a doubly curved diffracting optic disposed between the sample and the x-ray fluorescence detector for collecting x-ray fluorescence from the focal point on the sample and focusing the fluorescent x-rays towards the x-ray fluorescence detector.Type: GrantFiled: December 19, 2003Date of Patent: August 23, 2005Assignee: X-Ray Optical Systems, Inc.Inventors: Zewu Chen, David M. Gibson
-
Publication number: 20050157843Abstract: An x-ray fluorescence technique for detecting the level of arsenic in a sample of water or body fluid. Arsenic and lead are expected to fluoresce in a first energy band and lead is expected to also fluoresce separately in a second energy band. An excitation path directs x-rays toward the sample; a first detection path detects x-ray fluorescence of the first energy band from the sample; and a second detection path detects x-ray fluorescence of the second energy band from the sample. The level of arsenic can be obtained by analyzing the x-ray fluorescence from both detection paths, and using a constant which relates the level of lead in the second energy band to the level of lead in the first energy band. The excitation path and each detection path may each include a monochromating optic to transmit the desired x-ray energy band, e.g., a doubly curved optic.Type: ApplicationFiled: November 30, 2004Publication date: July 21, 2005Applicant: X-Ray Optical Systems, Inc.Inventors: Zewu Chen, Walter Gibson
-
Publication number: 20050053197Abstract: An x-ray source assembly (2700) and method of operation are provided having enhanced output stability. The assembly includes an anode (2125) having a source spot upon which electrons (2120) impinge and a control system (2715/2720) for controlling position of the anode source spot relative to an output structure. The control system can maintain the anode source spot location relative to the output structure (2710) notwithstanding a change in one or more operating conditions of the x-ray source assembly. One aspect of the disclosed invention is most amenable to the analysis of sulfur in petroleum-based fuels.Type: ApplicationFiled: June 3, 2004Publication date: March 10, 2005Applicant: X-Ray Optical Systems, Inc.Inventors: Ian Radley, Thomas Bievenue, John Burdett, Brian Gallagher, Stuart Shakshober, Zewu Chen, Michael Moore
-
Publication number: 20050036583Abstract: Measurement technique and apparatus for examining a region of a patterned surface such as an integrated circuit (IC). Excitation x-ray, neutron, particle-beam or gamma ray radiation is directed toward a two-dimensional sample area of the IC. Emissions (e.g., x-ray fluorescence—XRF) from the sample area are detected. A mask is placed in a planar radiation path formed by the source, detector and the sample area, and in one embodiment moveable relative to the sample area. The mask includes an elongate aperture to substantially confine the excitation radiation directed to the sample area, and the emissions from the sample area, to the planar radiation path when arranged parallel to a first axis of the two-dimensional sample area. The invention allows predictive measurement of feature characteristics in active circuit regions of the IC, using sample areas outside of these regions.Type: ApplicationFiled: August 12, 2003Publication date: February 17, 2005Applicants: X-Ray Optical Systems, Inc., Technos Co., Inc.Inventors: Zewu Chen, Shinichi Terada
-
Publication number: 20050031073Abstract: A method and apparatus for analyzing fluids by means of x-ray fluorescence. The method and apparatus are applicable to any fluid, including liquids and gases, having at least one component that emits x-ray fluorescence when exposed to x-rays. The apparatus includes an x-ray source (82) including an x-ray tube (64) having improved heat dissipating properties due to the thermal coupling of the x-ray tube with a thermally-conductive, dielectric material (70, 1150). The x-ray tube also includes means for aligning (100, 2150, 2715) the x-ray tube with the x-ray source housing whereby the orientation of the x-ray beam produced by the x-ray source can be optimized, and stabilized various over operating conditions. The method and apparatus may also include an x-ray detector having a small-area, for example, a PIN-diode type semiconductor x-ray detector (120), that can provide effective x-ray detection at room temperature.Type: ApplicationFiled: June 1, 2004Publication date: February 10, 2005Applicant: X-Ray Optical Systems, Inc.Inventors: Ian Radley, Thomas Bievenue, John Burdett, Brian Gallagher, Stuart Shakshober, Zewu Chen, Michael Moore
-
Patent number: 6829327Abstract: An improved total-reflection x-ray fluorescence (TXRF) apparatus using a doubly-curved optic is presented for use in detecting foreign matter on surfaces, for example, semiconductor wafers. The apparatus includes an x-ray source, a doubly-curved x-ray optic for diffracting and focusing the x-rays, a surface onto which at least some of the diffracted x-rays are directed, and an x-ray detector for detecting resultant x-ray fluorescence emitted by any foreign matter present on the surface One or more apertures may be provided for limiting the dispersion angle of the x-rays. The crystal or multi-layer doubly-curved optic typically adheres to Bragg's law of x-ray diffraction may be curved to a toroidal, ellipsoidal, spherical, parabolic, hyperbolic, or other doubly-curved shape. An apparatus for diffracting x-rays is also presented.Type: GrantFiled: September 22, 2000Date of Patent: December 7, 2004Assignee: X-Ray Optical Systems, Inc.Inventor: Zewu Chen
-
Publication number: 20040218725Abstract: A method and device for cooling and electrically-insulating a high-voltage, heat-generating component, for example, an x-ray tube (1105) for analyzing fluids by means of x-ray fluorescence. The device includes an x-ray source (1100) including an x-ray tube (1105) having improved heat-dissipating properties due to the thermal coupling of the x-ray tube with a thermally-conductive, dielectric material (1150). The device may include a base assembly (1135) mounted to the component for conducting heat away from the component while electrically isolating the component. In one aspect of the invention, the base assembly includes two copper plates (1140, 1145) separated by a dielectric plate (1150). The dielectric plate minimizes or prevents the leakage of current through the base assembly (1135). One aspect of the disclosed invention is most amenable to the analysis of sulfur in petroleum-based fuels.Type: ApplicationFiled: June 3, 2004Publication date: November 4, 2004Applicant: X-Ray Optical Systems, Inc.Inventors: Ian Radley, Thomas J. Bievenue, John H. Burdett, Brian W. Gallagher, Stuart M. Shakshober, Zewu Chen
-
Publication number: 20040131146Abstract: X-ray fluorescence (XRF) spectroscopy systems and methods are provided. One system includes a source of x-ray radiation and an excitation optic disposed between the x-ray radiation source and the sample for collecting x-ray radiation from the source and focusing the x-ray radiation to a focal point on the sample to incite at least one analyte in the sample to fluoresce. The system further includes an x-ray fluorescence detector and a collection optic comprising a doubly curved diffracting optic disposed between the sample and the x-ray fluorescence detector for collecting x-ray fluorescence from the focal point on the sample and focusing the fluorescent x-rays towards the x-ray fluorescence detector.Type: ApplicationFiled: December 19, 2003Publication date: July 8, 2004Applicant: X-Ray Optical Systems, Inc.Inventors: Zewu Chen, David M. Gibson
-
Patent number: 6317483Abstract: An optically curved device is presented for use in focusing or imaging x-rays from a divergent source. The device includes a plurality of curved atomic reflection planes, at least some of which are separated by a spacing d which varies in at least one direction across the optically curved device. A doubly curved optical surface is disposed over the plurality of curved reflection planes. The spacing d varies continuously in the at least one direction for enhanced matching of incident angles of x-rays from a divergent source impinging on the optical surface with the Bragg angles on at least some points of the optical surface. The doubly curved optical surface can have an elliptic, parabolic, spheric or aspheric profile.Type: GrantFiled: November 29, 1999Date of Patent: November 13, 2001Assignee: X-Ray Optical Systems, Inc.Inventor: Zewu Chen