Full-aperture x-ray tests of Kirkpatrick-Baez modules: preliminary results

NASA Astrophysics Data System (ADS)

Pina, L.; Marsikova, V.; Hudec, R.; Inneman, A.; Marsik, J.; Cash, W.; Shipley, A.; Zeiger, B.

2011-05-01

We report on preliminary results of full aperture X-ray optical tests at the X-ray test facility at the University of Colorado (USA) of four test modules of Kirkpatrick-Baez (KB) X-ray optical systems performed in August 2010. Direct experimental comparisons were made between gold-coated optics of two novel substrates: glass foils and silicon wafers. The preliminary results are promising, with full-width half-maxima of full stacks being of order of 30 arcsec in 2D full arrangement. These results justify further efforts to improve KB optics for use in low-cost, high-performance space-borne astronomical imaging instruments for X-ray wavelengths.

Transmitted wavefront testing with large dynamic range based on computer-aided deflectometry

NASA Astrophysics Data System (ADS)

Wang, Daodang; Xu, Ping; Gong, Zhidong; Xie, Zhongmin; Liang, Rongguang; Xu, Xinke; Kong, Ming; Zhao, Jun

2018-06-01

The transmitted wavefront testing technique is demanded for the performance evaluation of transmission optics and transparent glass, in which the achievable dynamic range is a key issue. A computer-aided deflectometric testing method with fringe projection is proposed for the accurate testing of transmitted wavefronts with a large dynamic range. Ray tracing of the modeled testing system is carried out to achieve the virtual ‘null’ testing of transmitted wavefront aberrations. The ray aberration is obtained from the ray tracing result and measured slope, with which the test wavefront aberration can be reconstructed. To eliminate testing system modeling errors, a system geometry calibration based on computer-aided reverse optimization is applied to realize accurate testing. Both numerical simulation and experiments have been carried out to demonstrate the feasibility and high accuracy of the proposed testing method. The proposed testing method can achieve a large dynamic range compared with the interferometric method, providing a simple, low-cost and accurate way for the testing of transmitted wavefronts from various kinds of optics and a large amount of industrial transmission elements.

X-Ray Testing Constellation-X Optics at MSFC's 100-m Facility

NASA Technical Reports Server (NTRS)

O'Dell, Stephen; Baker, Markus; Content, David; Freeman, Mark; Glenn, Paul; Gubarev, Mikhail; Hair, Jason; Jones, William; Joy, Marshall

2003-01-01

In addition to the 530-m-long X-Ray Calibration Facility (XRCF), NASA's Marshall Space Flight Center (MSFC) operates a 104-m-long (source-to-detector) X-ray-test facility. Originally developed and still occasionally used for stray-light testing of visible-fight optical systems, the so-called "Stray-Light Facility" now serves primarily as a convenient and inexpensive facility for performance evaluation and calibration of X-ray optics and detectors. The facility can accommodate X-ray optics up to about 1-m diameter and 12-m focal length. Currently available electron-impact sources at the facility span the approximate energy range 0.2 to 100 keV, thus supporting testing of soft- and hard-X-ray optics and detectors. Available MSFC detectors are a front-illuminated CCD (charge-coupled device) and a scanning CZT (cadmium--zinc--telluride) detector, with low-energy cut-offs of about 0.8 and 3 keV, respectively. In order to test developmental optics for the Constellation-X Project, led by NASA's Goddard Space Flight Center (GSFC), MSFC undertook several enhancements to the facility. Foremost among these was development and fabrication of a five-degree-of-freedom (5-DoF) optics mount and control system, which translates and tilts the user-provided mirror assembly suspended from its interface plate. Initial Constellation-X tests characterize the performance of the Optical Alignment Pathfinder Two (OAP2) for the large Spectroscopy X-ray Telescope (SXT) and of demonstration mirror assemblies for the Hard X-ray Telescope (HXT). With the Centroid Detector Assembly (CDA), used for precision alignment of the Chandra (nee AXAF) mirrors, the Constellation-X SXT Team optically aligned the individual mirrors of the OAPZ at GSFC. The team then developed set-up and alignment procedures, including transfer of the alignment from the optical alignment facility at GSFC to the X-ray test facility at MSFC, using a reference flat and fiducials. The OAPZ incorporates additional ancillary features --- fixed aperture mask and movable sub-aperture mask --- to facilitate X-ray characterization of the optics. Although the OAPZ was designed to- have low sensitivity to temperature offsets and gradients, analyses showed the necessity of active temperature control for the X-ray performance testing. Thus, the Smithsonian Astrophysical Observatory (SAO) implemented a thermal control and monitoring system, designed to hold the OAP2 close to its assembly.

The Development of a Simulator System and Hardware Test Bed for Deep Space X-Ray Navigation

NASA Astrophysics Data System (ADS)

Doyle, Patrick T.

2013-03-01

Currently, there is a considerable interest in developing technologies that will allow using photon measurements from celestial x-ray sources for deep space navigation. The impetus for this is that many envisioned future space missions will require spacecraft to have autonomous navigation capabilities. For missions close to Earth, Global Navigation Satellite Systems (GNSS) such as GPS are readily available for use, but for missions far from Earth, other alternatives must be provided. While existing systems such as the Deep Space Network (DSN) can be used, latencies associated with servicing a fleet of vehicles may not be compatible with some autonomous operations requiring timely updates of their navigation solution. Because of their somewhat predictable emissions, pulsars are the ideal candidates for x-ray sources that can be used to provide key parameters for navigation. Algorithms and simulation tools that will enable designing and analyzing x-ray navigation concepts are presented. The development of a compact x-ray detector system is pivotal to the eventual deployment of such navigation systems. Therefore, results of a high altitude balloon test to evaluate the design of a compact x-ray detector system are described as well.

SEXTANT X-Ray Pulsar Navigation Demonstration: Flight System and Test Results

NASA Technical Reports Server (NTRS)

Winternitz, Luke; Mitchell, Jason W.; Hassouneh, Munther A.; Valdez, Jennifer E.; Price, Samuel R.; Semper, Sean R.; Yu, Wayne H.; Ray, Paul S.; Wood, Kent S.; Arzoumanian, Zaven;

SEXTANT X-Ray Pulsar Navigation Demonstration: Flight System and Test Results

NASA Technical Reports Server (NTRS)

Winternitz, Luke M. B.; Mitchell, Jason W.; Hassouneh, Munther A.; Valdez, Jennifer E.; Price, Samuel R.; Semper, Sean R.; Yu, Wayne H.; Ray, Paul S.; Wood, Kent S.; Arzoumanian, Zaven;

Implementation of a preamplifier-amplifier system for radiation detectors used in Mössbauer spectroscopy

NASA Astrophysics Data System (ADS)

Velásquez, A. A.; Arroyave, M.

2014-01-01

We report the assembly and testing of a preamplification and amplification system for pulses produced by gaseous radiation detectors commonly used in Mössbauer spectroscopy. The system is composed by a pair of commercial integrated circuits A203 and A206, which operate as charge sensitive preamplifier-shaping amplifier and linear amplifier-low level discriminator, respectively. The integrated circuits were interconnected in the unipolar output mode and placed inside a metallic shielding, which prevents noise amplification for a suitable signal-noise ratio. The system was tested by irradiating a proportional counter LND-45431 with characteristic X rays of 6.3 keV and gamma rays of 14.4 keV emitted by a Mössbauer radioactive source of 57Co (Rh). Unipolar pulses with Gaussian profile were obtained at the output of the linear amplifier, whose amplitudes were close to 0.4 V for 6.3 keV X rays and 1.4 V for 14.4 keV gamma rays. Pulse height spectra showed that the system allows a satisfactory identification of the X-rays and gamma rays emitted by the 57Co source, giving the possibility to make a good selection of the 14.4 keV peak for having a suitable signal-noise ratio in the Mössbauer spectra. Absorption percentages of 14 % were found by taking the Mössbauer spectra of a natural iron absorber. The assembly and tests of the system are presented through this paper.

Fissile interrogation using gamma rays from oxygen

DOEpatents

Smith, Donald; Micklich, Bradley J.; Fessler, Andreas

2004-04-20

The subject apparatus provides a means to identify the presence of fissionable material or other nuclear material contained within an item to be tested. The system employs a portable accelerator to accelerate and direct protons to a fluorine-compound target. The interaction of the protons with the fluorine-compound target produces gamma rays which are directed at the item to be tested. If the item to be tested contains either a fissionable material or other nuclear material the interaction of the gamma rays with the material contained within the test item with result in the production of neutrons. A system of neutron detectors is positioned to intercept any neutrons generated by the test item. The results from the neutron detectors are analyzed to determine the presence of a fissionable material or other nuclear material.

Elemental X-ray mapping of agglutinated foraminifer tests: A non- destructive technique for determining compositional characteristics.

USGS Publications Warehouse

Commeau, R.F.; Reynolds, Leslie A.; Poag, C.W.

1985-01-01

The composition of agglutinated foraminiferal tests vary remarkably in response to local substrate characteristics, physiochemical properties of the water column and species- dependant selectivity of test components. We have employed a technique that combines a scanning electron microscope with an energy dispersive X-ray spectrometer system to identify major and minor elemental constituents of agglutinated foraminiferal walls. As a sample is bombarded with a beam of high energy electrons, X-rays are generated that are characteristic of the elements present. As a result, X- ray density maps can be produced for each of several elements present in the tests of agglutinated foraminifers. 

High-accuracy Aspheric X-ray Mirror Metrology Using Software Configurable Optical Test System/deflectometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Run; Su, Peng; Burge, James H.

The Software Configurable Optical Test System (SCOTS) uses deflectometry to measure surface slopes of general optical shapes without the need for additional null optics. Careful alignment of test geometry and calibration of inherent system error improve the accuracy of SCOTS to a level where it competes with interferometry. We report a SCOTS surface measurement of an off-axis superpolished elliptical x-ray mirror that achieves <1 nm<1 nm root-mean-square accuracy for the surface measurement with low-order term included.

An objectively-analyzed method for measuring the useful penetration of x-ray imaging systems.

PubMed

Glover, Jack L; Hudson, Lawrence T

2016-06-01

The ability to detect wires is an important capability of the cabinet x-ray imaging systems that are used in aviation security as well as the portable x-ray systems that are used by domestic law enforcement and military bomb squads. A number of national and international standards describe methods for testing this capability using the so called useful penetration test metric, where wires are imaged behind different thicknesses of blocking material. Presently, these tests are scored based on human judgments of wire visibility, which are inherently subjective. We propose a new method in which the useful penetration capabilities of an x-ray system are objectively evaluated by an image processing algorithm operating on digital images of a standard test object. The algorithm advantageously applies the Radon transform for curve parameter detection that reduces the problem of wire detection from two dimensions to one. The sensitivity of the wire detection method is adjustable and we demonstrate how the threshold parameter can be set to give agreement with human-judged results. The method was developed to be used in technical performance standards and is currently under ballot for inclusion in a US national aviation security standard.

An objectively-analyzed method for measuring the useful penetration of x-ray imaging systems

PubMed Central

Glover, Jack L.; Hudson, Lawrence T.

2016-01-01

The ability to detect wires is an important capability of the cabinet x-ray imaging systems that are used in aviation security as well as the portable x-ray systems that are used by domestic law enforcement and military bomb squads. A number of national and international standards describe methods for testing this capability using the so called useful penetration test metric, where wires are imaged behind different thicknesses of blocking material. Presently, these tests are scored based on human judgments of wire visibility, which are inherently subjective. We propose a new method in which the useful penetration capabilities of an x-ray system are objectively evaluated by an image processing algorithm operating on digital images of a standard test object. The algorithm advantageously applies the Radon transform for curve parameter detection that reduces the problem of wire detection from two dimensions to one. The sensitivity of the wire detection method is adjustable and we demonstrate how the threshold parameter can be set to give agreement with human-judged results. The method was developed to be used in technical performance standards and is currently under ballot for inclusion in a US national aviation security standard. PMID:27499586

An objectively-analyzed method for measuring the useful penetration of x-ray imaging systems

NASA Astrophysics Data System (ADS)

Glover, Jack L.; Hudson, Lawrence T.

2016-06-01

The ability to detect wires is an important capability of the cabinet x-ray imaging systems that are used in aviation security as well as the portable x-ray systems that are used by domestic law enforcement and military bomb squads. A number of national and international standards describe methods for testing this capability using the so called useful penetration test metric, where wires are imaged behind different thicknesses of blocking material. Presently, these tests are scored based on human judgments of wire visibility, which are inherently subjective. We propose a new method in which the useful penetration capabilities of an x-ray system are objectively evaluated by an image processing algorithm operating on digital images of a standard test object. The algorithm advantageously applies the Radon transform for curve parameter detection that reduces the problem of wire detection from two dimensions to one. The sensitivity of the wire detection method is adjustable and we demonstrate how the threshold parameter can be set to give agreement with human-judged results. The method was developed to be used in technical performance standards and is currently under ballot for inclusion in an international aviation security standard.

X-ray based extensometry

NASA Technical Reports Server (NTRS)

Jordan, E. H.; Pease, D. M.

1988-01-01

A totally new method of extensometry using an X-ray beam was proposed. The intent of the method is to provide a non-contacting technique that is immune to problems associated with density variations in gaseous environments that plague optical methods. X-rays are virtually unrefractable even by solids. The new method utilizes X-ray induced X-ray fluorescence or X-ray induced optical fluorescence of targets that have melting temperatures of over 3000 F. Many different variations of the basic approaches are possible. In the year completed, preliminary experiments were completed which strongly suggest that the method is feasible. The X-ray induced optical fluorescence method appears to be limited to temperatures below roughly 1600 F because of the overwhelming thermal optical radiation. The X-ray induced X-ray fluorescence scheme appears feasible up to very high temperatures. In this system there will be an unknown tradeoff between frequency response, cost, and accuracy. The exact tradeoff can only be estimated. It appears that for thermomechanical tests with cycle times on the order of minutes a very reasonable system may be feasible. The intended applications involve very high temperatures in both materials testing and monitoring component testing. Gas turbine engines, rocket engines, and hypersonic vehicles (NASP) all involve measurement needs that could partially be met by the proposed technology.

X-ray transport and radiation response assessment (XTRRA) experiments at the National Ignition Facility.

PubMed

Fournier, K B; Brown, C G; Yeoman, M F; Fisher, J H; Seiler, S W; Hinshelwood, D; Compton, S; Holdener, F R; Kemp, G E; Newlander, C D; Gilliam, R P; Froula, N; Lilly, M; Davis, J F; Lerch, Maj A; Blue, B E

2016-11-01

Our team has developed an experimental platform to evaluate the x-ray-generated stress and impulse in materials. Experimental activities include x-ray source development, design of the sample mounting hardware and sensors interfaced to the National Ignition Facility's diagnostics insertion system, and system integration into the facility. This paper focuses on the X-ray Transport and Radiation Response Assessment (XTRRA) test cassettes built for these experiments. The test cassette is designed to position six samples at three predetermined distances from the source, each known to within ±1% accuracy. Built-in calorimeters give in situ measurements of the x-ray environment along the sample lines of sight. The measured accuracy of sample responses as well as planned modifications to the XTRRA cassette is discussed.

Development of Camera Electronics for the Advanced Gamma-ray Imaging System (AGIS)

NASA Astrophysics Data System (ADS)

Tajima, Hiroyasu

2009-05-01

AGIS, a next generation of atmospheric Cherenkov telescope arrays, aims to achieve a sensitivity level of a milliCrab for gamma-ray observations in in the energy band of 40 GeV to 100 TeV. Such improvement requires cost reduction of individual components with high reliability in order to equip the order of 100 telescopes necessary to achieve the sensitivity goal. We are exploring several design concepts to reduce the cost of camera electronics while improving their performance. We have developed test systems for some of these concepts and are testing their performance. Here we present test results of the test systems.

High resolution X-ray CT for advanced electronics packaging

NASA Astrophysics Data System (ADS)

Oppermann, M.; Zerna, T.

2017-02-01

Advanced electronics packaging is a challenge for non-destructive Testing (NDT). More, smaller and mostly hidden interconnects dominate modern electronics components and systems. To solve the demands of customers to get products with a high functionality by low volume, weight and price (e.g. mobile phones, personal medical monitoring systems) often the designers use System-in-Package solutions (SiP). The non-destructive testing of such devices is a big challenge. So our paper will impart fundamentals and applications for non-destructive evaluation of inner structures of electronics packaging for quality assurance and reliability investigations with a focus on X-ray methods, especially on high resolution X-ray computed tomography (CT).

Event-Driven X-Ray CCD Detectors for High Energy Astrophysics

NASA Technical Reports Server (NTRS)

Ricker, George R.

2004-01-01

A viewgraph presentation describing the Event-Driven X- Ray CCD (EDCCD) detector system for high energy astrophysics is presented. The topics include: 1) EDCCD: Description and Advantages; 2) Summary of Grant Activity Carried Out; and 3) EDCCD Test System.

X ray attenuation measurements for high-temperature materials characterization and in-situ monitoring of damage accumulation. Ph.D. Thesis - Cleveland State Univ., 1991

NASA Technical Reports Server (NTRS)

Baaklini, George Y.

1992-01-01

The scope of this dissertation is to develop and apply x ray attenuation measurement systems that are capable of: (1) characterizing density variations in high-temperature materials, e.g., monolithic ceramics, ceramic and intermetallic matrix composites, and (2) noninvasively monitoring damage accumulation and failure sequences in ceramic matrix composites under room temperature tensile testing. This dissertation results in the development of: (1) a point scan digital radiography system, and (2) an in-situ x ray material testing system. Radiographic evaluation before, during, and after loading shows the effect of preexisting volume flaws on the fracture behavior of composites. Results show that x ray film radiography can monitor damage accumulation during tensile loading. Matrix cracking, fiber matrix debonding, fiber bridging, and fiber pullout are imaged throughout the tensile loading of the specimens. Further in-situ radiography is found to be a practical technique for estimating interfacial shear strength between the silicon carbide fibers and the reaction bonded silicon nitride matrix. It is concluded that pretest, in-situ, and post test x ray imaging can provide for greater understanding of ceramic matrix composite mechanical behavior.

X-ray transport and radiation response assessment (XTRRA) experiments at the National Ignition Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fournier, K. B., E-mail: fournier2@llnl.gov; Brown, C. G.; Yeoman, M. F.

2016-11-15

Our team has developed an experimental platform to evaluate the x-ray-generated stress and impulse in materials. Experimental activities include x-ray source development, design of the sample mounting hardware and sensors interfaced to the National Ignition Facility’s diagnostics insertion system, and system integration into the facility. This paper focuses on the X-ray Transport and Radiation Response Assessment (XTRRA) test cassettes built for these experiments. The test cassette is designed to position six samples at three predetermined distances from the source, each known to within ±1% accuracy. Built-in calorimeters give in situ measurements of the x-ray environment along the sample lines ofmore » sight. The measured accuracy of sample responses as well as planned modifications to the XTRRA cassette is discussed.« less

X-ray transport and radiation response assessment (XTRRA) experiments at the National Ignition Facility

DOE PAGES

Fournier, K. B.; Brown, Jr., C. G.; Yeoman, M. F.; ...

2016-08-10

Our team has developed an experimental platform to evaluate the x-ray-generated stress and impulse in materials. Experimental activities include x-ray source development, design of the sample mounting hardware and sensors interfaced to the NIF’s diagnostics insertion system, and system integration into the facility. This paper focuses on the X-ray Transport and Radiation Response Assessment (XTRRA) test cassettes built for these experiments. The test cassette is designed to position six samples at three predetermined distances from the source, each known to within ±1% accuracy. Built in calorimeters give in situ measurements of the x-ray environment along the sample lines of sight.more » We discuss the measured accuracy of sample responses, as well as planned modifications to the XTRRA cassette.« less

Design and implemention of a multi-functional x-ray computed tomography system

NASA Astrophysics Data System (ADS)

Li, Lei; Xi, Xiaoqi; Han, Yu; Yan, Bin; Zhang, Xiang; Deng, Lin; Chen, Siyu; Jin, Zhao; Li, Zengguang

2015-10-01

A powerful volume X-ray tomography system has been designed and constructed to provide an universal tool for the three-dimensional nondestructive testing and investigation of industrial components, automotive, electronics, aerospace components, new materials, etc. The combined system is equipped with two commercial X-ray sources, sharing one flat panel detector of 400mm×400mm. The standard focus 450kV high-energy x-ray source is optimized for complex and high density components such as castings, engine blocks and turbine blades. And the microfocus 225kV x-ray source is to meet the demands of micro-resolution characterization applications. Thus the system's penetration capability allows to scan large objects up to 200mm thick dense materials, and the resolution capability can meet the demands of 20μm microstructure inspection. A high precision 6-axis manipulator system is fitted, capable of offset scanning mode in large field of view requirements. All the components are housed in a room with barium sulphate cement. On the other hand, the presented system expands the scope of applications such as dual energy research and testing. In this paper, the design and implemention of the flexible system is described, as well as the preliminary tomographic imaging results of an automobile engine block.

X-ray phase scanning setup for non-destructive testing using Talbot-Lau interferometer

NASA Astrophysics Data System (ADS)

Bachche, S.; Nonoguchi, M.; Kato, K.; Kageyama, M.; Koike, T.; Kuribayashi, M.; Momose, A.

2016-09-01

X-ray grating interferometry has a great potential for X-ray phase imaging over conventional X-ray absorption imaging which does not provide significant contrast for weakly absorbing objects and soft biological tissues. X-ray Talbot and Talbot-Lau interferometers which are composed of transmission gratings and measure the differential X-ray phase shifts have gained popularity because they operate with polychromatic beams. In X-ray radiography, especially for nondestructive testing in industrial applications, the feasibility of continuous sample scanning is not yet completely revealed. A scanning setup is frequently advantageous when compared to a direct 2D static image acquisition in terms of field of view, exposure time, illuminating radiation, etc. This paper demonstrates an efficient scanning setup for grating-based Xray phase imaging using laboratory-based X-ray source. An apparatus consisting of an X-ray source that emits X-rays vertically, optical gratings and a photon-counting detector was used with which continuously moving objects across the field of view as that of conveyor belt system can be imaged. The imaging performance of phase scanner was tested by scanning a long continuous moving sample at a speed of 5 mm/s and absorption, differential-phase and visibility images were generated by processing non-uniform moire movie with our specially designed phase measurement algorithm. A brief discussion on the feasibility of phase scanner with scanning setup approach including X-ray phase imaging performance is reported. The successful results suggest a breakthrough for scanning objects those are moving continuously on conveyor belt system non-destructively using the scheme of X-ray phase imaging.

RESOLVE Project

NASA Technical Reports Server (NTRS)

Parker, Ray O.

2012-01-01

The RESOLVE project is a lunar prospecting mission whose primary goal is to characterize water and other volatiles in lunar regolith. The Lunar Advanced Volatiles Analysis (LAVA) subsystem is comprised of a fluid subsystem that transports flow to the gas chromatograph- mass spectrometer (GC-MS) instruments that characterize volatiles and the Water Droplet Demonstration (WDD) that will capture and display water condensation in the gas stream. The LAVA Engineering Test Unit (ETU) is undergoing risk reduction testing this summer and fall within a vacuum chamber to understand and characterize C!Jmponent and integrated system performance. Ray will be assisting with component testing of line heaters, printed circuit heaters, pressure transducers, temperature sensors, regulators, and valves in atmospheric and vacuum environments. He will be developing procedures to guide these tests and test reports to analyze and draw conclusions from the data. In addition, he will gain experience with preparing a vacuum chamber with fluid and electrical connections. Further testing will include integrated testing of the fluid subsystem with the gas supply system, near-infrared spectrometer, WDD, Sample Delivery System, and GC-MS in the vacuum chamber. This testing will provide hands-on exposure to a flight forward spaceflight subsystem, the processes associated with testing equipment in a vacuum chamber, and experience working in a laboratory setting. Examples of specific analysis Ray will conduct include: pneumatic analysis to calculate the WOO's efficiency at extracting water vapor from the gas stream to form condensation; thermal analysis of the conduction and radiation along a line connecting two thermal masses; and proportional-integral-derivative (PID) heater control analysis. In this Research and Technology environment, Ray will be asked to problem solve real-time as issues arise. Since LAVA is a scientific subsystem, Ray will be utilizing his chemical engineering background to operate the near-infrared spectrometer and GC-MS instruments during ETU testing. Ray will be working with Modified Commercial off the Shelf (MCOTS) instruments and characterizing their analytical behavior for optimization. Ray will be offered the opportunity to suggest testing modifications or configuration changes at any time to improve the experimental effectiveness. He will gain many skills needed for working in a technical team setting requiring flexibility and critical thinking.

Adaptive x-ray threat detection using sequential hypotheses testing with fan-beam experimental data (Conference Presentation)

NASA Astrophysics Data System (ADS)

Thamvichai, Ratchaneekorn; Huang, Liang-Chih; Ashok, Amit; Gong, Qian; Coccarelli, David; Greenberg, Joel A.; Gehm, Michael E.; Neifeld, Mark A.

2017-05-01

We employ an adaptive measurement system, based on sequential hypotheses testing (SHT) framework, for detecting material-based threats using experimental data acquired on an X-ray experimental testbed system. This testbed employs 45-degree fan-beam geometry and 15 views over a 180-degree span to generate energy sensitive X-ray projection data. Using this testbed system, we acquire multiple view projection data for 200 bags. We consider an adaptive measurement design where the X-ray projection measurements are acquired in a sequential manner and the adaptation occurs through the choice of the optimal "next" source/view system parameter. Our analysis of such an adaptive measurement design using the experimental data demonstrates a 3x-7x reduction in the probability of error relative to a static measurement design. Here the static measurement design refers to the operational system baseline that corresponds to a sequential measurement using all the available sources/views. We also show that by using adaptive measurements it is possible to reduce the number of sources/views by nearly 50% compared a system that relies on static measurements.

National Synchrotron Light Source annual report 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hulbert, S.L.; Lazarz, N.M.

1992-04-01

This report discusses the following research conducted at NSLS: atomic and molecular science; energy dispersive diffraction; lithography, microscopy and tomography; nuclear physics; UV photoemission and surface science; x-ray absorption spectroscopy; x-ray scattering and crystallography; x-ray topography; workshop on surface structure; workshop on electronic and chemical phenomena at surfaces; workshop on imaging; UV FEL machine reviews; VUV machine operations; VUV beamline operations; VUV storage ring parameters; x-ray machine operations; x-ray beamline operations; x-ray storage ring parameters; superconducting x-ray lithography source; SXLS storage ring parameters; the accelerator test facility; proposed UV-FEL user facility at the NSLS; global orbit feedback systems; and NSLSmore » computer system.« less

Design and Tests of the Hard X-Ray Polarimeter X-Calibur

NASA Technical Reports Server (NTRS)

Beilicke, M.; Binns, W. R.; Buckley, J.; Cowsik, R.; Dowkontt, P.; Garson, A.; Guo, Q.; Israel, M. H.; Lee, K.; Krawczynski, H.;

Design and Tests of the Hard X-Ray Polarimeter X-Calibur

NASA Technical Reports Server (NTRS)

Beilicke, M.; Baring, M. G.; Barthelmy, S.; Binns, W. R.; Buckley, J.; Cowsik, R.; Dowkontt, P.; Garson, A.; Guo, Q.; Haba, Y.;

Ultra-short wavelength x-ray system

DOEpatents

Umstadter, Donald [Ann Arbor, MI; He, Fei [Ann Arbor, MI; Lau, Yue-Ying [Potomac, MD

2008-01-22

A method and apparatus to generate a beam of coherent light including x-rays or XUV by colliding a high-intensity laser pulse with an electron beam that is accelerated by a synchronized laser pulse. Applications include x-ray and EUV lithography, protein structural analysis, plasma diagnostics, x-ray diffraction, crack analysis, non-destructive testing, surface science and ultrafast science.

Automating High-Precision X-Ray and Neutron Imaging Applications with Robotics

DOE PAGES

Hashem, Joseph Anthony; Pryor, Mitch; Landsberger, Sheldon; ...

2017-03-28

Los Alamos National Laboratory and the University of Texas at Austin recently implemented a robotically controlled nondestructive testing (NDT) system for X-ray and neutron imaging. This system is intended to address the need for accurate measurements for a variety of parts and, be able to track measurement geometry at every imaging location, and is designed for high-throughput applications. This system was deployed in a beam port at a nuclear research reactor and in an operational inspection X-ray bay. The nuclear research reactor system consisted of a precision industrial seven-axis robot, 1.1-MW TRIGA research reactor, and a scintillator-mirror-camera-based imaging system. Themore » X-ray bay system incorporated the same robot, a 225-keV microfocus X-ray source, and a custom flat panel digital detector. The robotic positioning arm is programmable and allows imaging in multiple configurations, including planar, cylindrical, as well as other user defined geometries that provide enhanced engineering evaluation capability. The imaging acquisition device is coupled with the robot for automated image acquisition. The robot can achieve target positional repeatability within 17 μm in the 3-D space. Flexible automation with nondestructive imaging saves costs, reduces dosage, adds imaging techniques, and achieves better quality results in less time. Specifics regarding the robotic system and imaging acquisition and evaluation processes are presented. In conclusion, this paper reviews the comprehensive testing and system evaluation to affirm the feasibility of robotic NDT, presents the system configuration, and reviews results for both X-ray and neutron radiography imaging applications.« less

Automating High-Precision X-Ray and Neutron Imaging Applications with Robotics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hashem, Joseph Anthony; Pryor, Mitch; Landsberger, Sheldon

Los Alamos National Laboratory and the University of Texas at Austin recently implemented a robotically controlled nondestructive testing (NDT) system for X-ray and neutron imaging. This system is intended to address the need for accurate measurements for a variety of parts and, be able to track measurement geometry at every imaging location, and is designed for high-throughput applications. This system was deployed in a beam port at a nuclear research reactor and in an operational inspection X-ray bay. The nuclear research reactor system consisted of a precision industrial seven-axis robot, 1.1-MW TRIGA research reactor, and a scintillator-mirror-camera-based imaging system. Themore » X-ray bay system incorporated the same robot, a 225-keV microfocus X-ray source, and a custom flat panel digital detector. The robotic positioning arm is programmable and allows imaging in multiple configurations, including planar, cylindrical, as well as other user defined geometries that provide enhanced engineering evaluation capability. The imaging acquisition device is coupled with the robot for automated image acquisition. The robot can achieve target positional repeatability within 17 μm in the 3-D space. Flexible automation with nondestructive imaging saves costs, reduces dosage, adds imaging techniques, and achieves better quality results in less time. Specifics regarding the robotic system and imaging acquisition and evaluation processes are presented. In conclusion, this paper reviews the comprehensive testing and system evaluation to affirm the feasibility of robotic NDT, presents the system configuration, and reviews results for both X-ray and neutron radiography imaging applications.« less

Microfocus/Polycapillary-Optic Crystallographic X-Ray System

NASA Technical Reports Server (NTRS)

Joy, Marshall; Gubarev, Mikhail; Ciszak, Ewa

2005-01-01

A system that generates an intense, nearly collimated, nearly monochromatic, small-diameter x-ray beam has been developed for use in macromolecular crystallography. A conventional x-ray system for macromolecular crystallography includes a rotating-anode x-ray source, which is massive (.500 kg), large (approximately 2 by 2 by 1 m), and power-hungry (between 2 and 18 kW). In contrast, the present system generates a beam of the required brightness from a microfocus source, which is small and light enough to be mounted on a laboratory bench, and operates at a power level of only tens of watts. The figure schematically depicts the system as configured for observing x-ray diffraction from a macromolecular crystal. In addition to the microfocus x-ray source, the system includes a polycapillary optic . a monolithic block (typically a bundle of fused glass tubes) that contains thousands of straight or gently curved capillary channels, along which x-rays propagate with multiple reflections. This particular polycapillary optic is configured to act as a collimator; the x-ray beam that emerges from its output face consists of quasi-parallel subbeams with a small angular divergence and a diameter comparable to the size of a crystal to be studied. The gap between the microfocus x-ray source and the input face of the polycapillary optic is chosen consistently with the focal length of the polycapillary optic and the need to maximize the solid angle subtended by the optic in order to maximize the collimated x-ray flux. The spectrum from the source contains a significant component of Cu K (photon energy is 8.08 keV) radiation. The beam is monochromatized (for Cu K ) by a nickel filter 10 m thick. In a test, this system was operated at a power of 40 W (current of 897 A at an accelerating potential of 45 kV), with an anode x-ray spot size of 41+/-2 microns. Also tested, in order to provide a standard for comparison, was a commercial rotating-anode x-ray crystallographic system with a pyrolytic graphite monochromator and a 250-micron pinhole collimator, operating at a power of 3.15 kW (current of 70 mA at an accelerating potential of 45 kV). The flux of collimated Cu K radiation in this system was found to be approximately 16 times that in the rotatinganode system. Data on x-ray diffraction from crystals of tetragonal form of lysozyme (protein) in this system were found to be of high quality and to be reducible by use of standard crystallographic software.

Application of X-ray television image system to observation in solid rocket motor

NASA Astrophysics Data System (ADS)

Fujiwara, T.; Ito, K.; Tanemura, T.; Shimizu, M.; Godai, T.

The X-ray television image system is used to observe the solid propellant burning surface during rocket motor operation as well as to inspect defects in solid rocket motors in a real time manner. This system can test 200 mm diameter dummy propellant rocket motors with under 2 percent discriminative capacity. Viewing of a 50 mm diameter internal-burning rocket motor, propellant burning surface time transition and propellant burning process of the surroundings of artificial defects were satisfactorily observed. The system was demonstrated to be effective for nondestructive testing and combustion research of solid rocket motors.

National Synchrotron Light Source annual report 1991. Volume 1, October 1, 1990--September 30, 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hulbert, S.L.; Lazarz, N.M.

1992-04-01

This report discusses the following research conducted at NSLS: atomic and molecular science; energy dispersive diffraction; lithography, microscopy and tomography; nuclear physics; UV photoemission and surface science; x-ray absorption spectroscopy; x-ray scattering and crystallography; x-ray topography; workshop on surface structure; workshop on electronic and chemical phenomena at surfaces; workshop on imaging; UV FEL machine reviews; VUV machine operations; VUV beamline operations; VUV storage ring parameters; x-ray machine operations; x-ray beamline operations; x-ray storage ring parameters; superconducting x-ray lithography source; SXLS storage ring parameters; the accelerator test facility; proposed UV-FEL user facility at the NSLS; global orbit feedback systems; and NSLSmore » computer system.« less

Practical Applications of Cosmic Ray Science: Spacecraft, Aircraft, Ground Based Computation and Control Systems and Human Health and Safety

NASA Technical Reports Server (NTRS)

Atwell, William; Koontz, Steve; Normand, Eugene

2012-01-01

In this paper we review the discovery of cosmic ray effects on the performance and reliability of microelectronic systems as well as on human health and safety, as well as the development of the engineering and health science tools used to evaluate and mitigate cosmic ray effects in earth surface, atmospheric flight, and space flight environments. Three twentieth century technological developments, 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems, have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools (e.g. ground based test methods as well as high energy particle transport and reaction codes) needed to design, test, and verify the safety and reliability of modern complex electronic systems as well as effects on human health and safety. The effects of primary cosmic ray particles, and secondary particle showers produced by nuclear reactions with spacecraft materials, can determine the design and verification processes (as well as the total dollar cost) for manned and unmanned spacecraft avionics systems. Similar considerations apply to commercial and military aircraft operating at high latitudes and altitudes near the atmospheric Pfotzer maximum. Even ground based computational and controls systems can be negatively affected by secondary particle showers at the Earth's surface, especially if the net target area of the sensitive electronic system components is large. Accumulation of both primary cosmic ray and secondary cosmic ray induced particle shower radiation dose is an important health and safety consideration for commercial or military air crews operating at high altitude/latitude and is also one of the most important factors presently limiting manned space flight operations beyond low-Earth orbit (LEO).

Development and application of variable-magnification x-ray Bragg optics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hirano, Keiichi, E-mail: keiichi.hirano@kek.jp; Takahashi, Yumiko; Sugiyama, Hiroshi

2016-07-27

A novel x-ray Bragg optics was developed for variable-magnification of an x-ray beam, and was combined with a module of the PILATUS pixel detector. A feasibility test of this optical system was carried out at the vertical-wiggler beamline BL-14B of the Photon Factory. By tuning the magnification factor, we could successfully control the spatial resolution of the optical system between 28 μm and 280 μm. X-ray absorption-contrast images of a leaf were observed at various magnification factors.

An explosives detection system for airline security using coherent x-ray scattering technology

NASA Astrophysics Data System (ADS)

Madden, Robert W.; Mahdavieh, Jacob; Smith, Richard C.; Subramanian, Ravi

2008-08-01

L-3 Communications Security and Detection Systems (SDS) has developed a new system for automated alarm resolution in airline baggage Explosive Detection Systems (EDS) based on coherent x-ray scattering spectroscopy. The capabilities of the system were demonstrated in tests with concealed explosives at the Transportation Security Laboratory and airline passenger baggage at Orlando International Airport. The system uses x-ray image information to identify suspicious objects and performs targeted diffraction measurements to classify them. This extra layer of detection capability affords a significant reduction in the rate of false alarm objects that must presently be resolved by opening passenger bags for hand inspection.

DoD Role in Counterdrug Operations - Can We Achieve Better Results?

DTIC Science & Technology

1999-04-01

drug detection 34 requirement. Tests showed fully loaded containers can be effectively screened for narcotics with high energy X - ray technologies...The DOD and the U.S. Customs Service are procuring X - ray systems with higher energy level, mobile X - ray systems, and even more advanced handheld...reduction in domestic marijuana cultivation and methamphetamine production by the year 2002. Long term objectives include a 30 percent reduction in the flow

A State Change In The Missing Link Binary Pulsar System Psr J1023+0038

DOE PAGES

Stappers, B. W.; Archibald, A. M.; Hessels, J. W. T.; ...

2014-07-01

We present radio, X-ray, and γ-ray observations which reveal that the binary millisecond pulsar / low-mass X-ray binary transition system PSR J1023+0038 has undergone a transformation in state. Whereas until recently the system harbored a bright millisecond radio pulsar, the radio pulsations at frequencies between 300 to 5000MHz have now become undetectable. Concurrent with this radio disappearance, the γ-ray flux of the system has quintupled. We conclude that, though the radio pulsar is currently not detectable, the pulsar mechanism is still active and the pulsar wind, as well as a newly formed accretion disk, are together providing the necessary conditionsmore » to create the γ-ray increase. The system is the first example of a transient, compact, low-mass γ-ray binary and will continue to provide an exceptional test bed for better understanding the formation of millisecond pulsars as well as accretion onto neutron stars in general.« less

Practical Applications of Cosmic Ray Science: Spacecraft, Aircraft, Ground-Based Computation and Control Systems, and Human Health and Safety

NASA Technical Reports Server (NTRS)

Atwell, William; Koontz, Steve; Normand, Eugene

2012-01-01

Three twentieth century technological developments, 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems, have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools needed to design, test, and verify the safety and reliability of modern complex technological systems. The effects of primary cosmic ray particles and secondary particle showers produced by nuclear reactions with the atmosphere, can determine the design and verification processes (as well as the total dollar cost) for manned and unmanned spacecraft avionics systems. Similar considerations apply to commercial and military aircraft operating at high latitudes and altitudes near the atmospheric Pfotzer maximum. Even ground based computational and controls systems can be negatively affected by secondary particle showers at the Earth s surface, especially if the net target area of the sensitive electronic system components is large. Finally, accumulation of both primary cosmic ray and secondary cosmic ray induced particle shower radiation dose is an important health and safety consideration for commercial or military air crews operating at high altitude/latitude and is also one of the most important factors presently limiting manned space flight operations beyond low-Earth orbit (LEO). In this paper we review the discovery of cosmic ray effects on the performance and reliability of microelectronic systems as well as human health and the development of the engineering and health science tools used to evaluate and mitigate cosmic ray effects in ground-based atmospheric flight, and space flight environments. Ground test methods applied to microelectronic components and systems are used in combinations with radiation transport and reaction codes to predict the performance of microelectronic systems in their operating environments. Similar radiation transport codes are used to evaluate possible human health effects of cosmic ray exposure, however, the health effects are based on worst-case analysis and extrapolation of a very limited human exposure data base combined with some limited experimental animal data. Finally, the limitations on human space operations beyond low-Earth orbit imposed by long term exposure to galactic cosmic rays are discussed.

Method and apparatus for measuring enrichment of UF6

DOEpatents

Hill, Thomas Roy [Santa Fe, NM; Ianakiev, Kiril Dimitrov [Los Alamos, NM

2011-06-07

A system and method are disclosed for determining the enrichment of .sup.235U in Uranium Hexafluoride (UF6) utilizing synthesized X-rays which are directed at a container test zone containing a sample of UF6. A detector placed behind the container test zone then detects and counts the X-rays which pass through the container and the UF6. In order to determine the portion of the attenuation due to the UF6 gas alone, this count rate may then be compared to a calibration count rate of X-rays passing through a calibration test zone which contains a vacuum, the test zone having experienced substantially similar environmental conditions as the actual test zone. Alternatively, X-rays of two differing energy levels may be alternately directed at the container, where either the container or the UF6 has a high sensitivity to the difference in the energy levels, and the other having a low sensitivity.

A novel lobster-eye imaging system based on Schmidt-type objective for X-ray-backscattering inspection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Jie; Wang, Xin, E-mail: wangx@tongji.edu.cn, E-mail: mubz@tongji.edu.cn; Zhan, Qi

This paper presents a novel lobster-eye imaging system for X-ray-backscattering inspection. The system was designed by modifying the Schmidt geometry into a treble-lens structure in order to reduce the resolution difference between the vertical and horizontal directions, as indicated by ray-tracing simulations. The lobster-eye X-ray imaging system is capable of operating over a wide range of photon energies up to 100 keV. In addition, the optics of the lobster-eye X-ray imaging system was tested to verify that they meet the requirements. X-ray-backscattering imaging experiments were performed in which T-shaped polymethyl-methacrylate objects were imaged by the lobster-eye X-ray imaging system basedmore » on both the double-lens and treble-lens Schmidt objectives. The results show similar resolution of the treble-lens Schmidt objective in both the vertical and horizontal directions. Moreover, imaging experiments were performed using a second treble-lens Schmidt objective with higher resolution. The results show that for a field of view of over 200 mm and with a 500 mm object distance, this lobster-eye X-ray imaging system based on a treble-lens Schmidt objective offers a spatial resolution of approximately 3 mm.« less

A novel lobster-eye imaging system based on Schmidt-type objective for X-ray-backscattering inspection

NASA Astrophysics Data System (ADS)

Xu, Jie; Wang, Xin; Zhan, Qi; Huang, Shengling; Chen, Yifan; Mu, Baozhong

2016-07-01

This paper presents a novel lobster-eye imaging system for X-ray-backscattering inspection. The system was designed by modifying the Schmidt geometry into a treble-lens structure in order to reduce the resolution difference between the vertical and horizontal directions, as indicated by ray-tracing simulations. The lobster-eye X-ray imaging system is capable of operating over a wide range of photon energies up to 100 keV. In addition, the optics of the lobster-eye X-ray imaging system was tested to verify that they meet the requirements. X-ray-backscattering imaging experiments were performed in which T-shaped polymethyl-methacrylate objects were imaged by the lobster-eye X-ray imaging system based on both the double-lens and treble-lens Schmidt objectives. The results show similar resolution of the treble-lens Schmidt objective in both the vertical and horizontal directions. Moreover, imaging experiments were performed using a second treble-lens Schmidt objective with higher resolution. The results show that for a field of view of over 200 mm and with a 500 mm object distance, this lobster-eye X-ray imaging system based on a treble-lens Schmidt objective offers a spatial resolution of approximately 3 mm.

Verification technology of remote sensing camera satellite imaging simulation based on ray tracing

NASA Astrophysics Data System (ADS)

Gu, Qiongqiong; Chen, Xiaomei; Yang, Deyun

2017-08-01

Remote sensing satellite camera imaging simulation technology is broadly used to evaluate the satellite imaging quality and to test the data application system. But the simulation precision is hard to examine. In this paper, we propose an experimental simulation verification method, which is based on the test parameter variation comparison. According to the simulation model based on ray-tracing, the experiment is to verify the model precision by changing the types of devices, which are corresponding the parameters of the model. The experimental results show that the similarity between the imaging model based on ray tracing and the experimental image is 91.4%, which can simulate the remote sensing satellite imaging system very well.

42 CFR 419.2 - Basis of payment.

Code of Federal Regulations, 2013 CFR

2013-10-01

... prospective payment system establishes a national payment rate, standardized for geographic wage differences... X-ray tests, diagnostic laboratory tests, and other diagnostic tests; (10) Durable medical equipment...

In-field tests of the EURITRACK tagged neutron inspection system

NASA Astrophysics Data System (ADS)

Carasco, C.; Perot, B.; Bernard, S.; Mariani, A.; Szabo, J.-L.; Sannie, G.; Roll, Th.; Valkovic, V.; Sudac, D.; Viesti, G.; Lunardon, M.; Bottosso, C.; Fabris, D.; Nebbia, G.; Pesente, S.; Moretto, S.; Zenoni, A.; Donzella, A.; Moszynski, M.; Gierlik, M.; Batsch, T.; Wolski, D.; Klamra, W.; Le Tourneur, P.; Lhuissier, M.; Colonna, A.; Tintori, C.; Peerani, P.; Sequeira, V.; Salvato, M.

2008-04-01

The EURopean Illicit TRAfficking Countermeasures Kit (EURITRACK) inspection system has been designed to complement X-ray scanners in the detection of explosives and other illicit materials hidden in cargo containers. The containers are interrogated by a 14-MeV tagged neutron beam at any suspect position in the X-ray image. Interrogation of a specific volume element with tagged neutrons yields information about the chemical composition of the material. Implementation and performance tests of the EURITRACK system in the Port of Rijeka in Croatia are described. Cargo container inspection results are reported and discussed.

Engine materials characterization and damage monitoring by using x ray technologies

NASA Technical Reports Server (NTRS)

Baaklini, George Y.

1993-01-01

X ray attenuation measurement systems that are capable of characterizing density variations in monolithic ceramics and damage due to processing and/or mechanical testing in ceramic and intermetallic matrix composites are developed and applied. Noninvasive monitoring of damage accumulation and failure sequences in ceramic matrix composites is used during room-temperature tensile testing. This work resulted in the development of a point-scan digital radiography system and an in situ x ray material testing system. The former is used to characterize silicon carbide and silicon nitride specimens, and the latter is used to image the failure behavior of silicon-carbide-fiber-reinforced, reaction-bonded silicon nitride matrix composites. State-of-the-art x ray computed tomography is investigated to determine its capabilities and limitations in characterizing density variations of subscale engine components (e.g., a silicon carbide rotor, a silicon nitride blade, and a silicon-carbide-fiber-reinforced beta titanium matrix rod, rotor, and ring). Microfocus radiography, conventional radiography, scanning acoustic microscopy, and metallography are used to substantiate the x ray computed tomography findings. Point-scan digital radiography is a viable technique for characterizing density variations in monolithic ceramic specimens. But it is very limited and time consuming in characterizing ceramic matrix composites. Precise x ray attenuation measurements, reflecting minute density variations, are achieved by photon counting and by using microcollimators at the source and the detector. X ray computed tomography is found to be a unique x ray attenuation measurement technique capable of providing cross-sectional spatial density information in monolithic ceramics and metal matrix composites. X ray computed tomography is proven to accelerate generic composite component development. Radiographic evaluation before, during, and after loading shows the effect of preexisting volume flaws on the fracture behavior of composites. Results from one-, three-, five-, and eight-ply ceramic composite specimens show that x ray film radiography can monitor damage accumulation during tensile loading. Matrix cracking, fiber-matrix debonding, fiber bridging, and fiber pullout are imaged throughout the tensile loading of the specimens. In situ film radiography is found to be a practical technique for estimating interfacial shear strength between the silicon carbide fibers and the reaction-bonded silicon nitride matrix. It is concluded that pretest, in situ, and post-test x ray imaging can provide greater understanding of ceramic matrix composite mechanical behavior.

X-ray tests of a microchannel plate detector and amorphous silicon pixel array readout for neutron radiography

NASA Astrophysics Data System (ADS)

Ambrosi, R. M.; Street, R.; Feller, B.; Fraser, G. W.; Watterson, J. I. W.; Lanza, R. C.; Dowson, J.; Ross, D.; Martindale, A.; Abbey, A. F.; Vernon, D.

2007-03-01

High-performance large area imaging detectors for fast neutrons in the 5-14 MeV energy range do not exist at present. The aim of this project is to combine microchannel plates or MCPs (or similar electron multiplication structures) traditionally used in image intensifiers and X-ray detectors with amorphous silicon (a-Si) pixel arrays to produce a composite converter and intensifier position sensitive imaging system. This detector will provide an order of magnitude improvement in image resolution when compared with current millimetre resolution limits obtained using phosphor or scintillator-based hydrogen rich converters. In this study we present the results of the initial experimental evaluation of the prototype system. This study was carried out using a medical X-ray source for the proof of concept tests, the next phase will involve neutron imaging tests. The hybrid detector described in this study is a unique development and paves the way for large area position sensitive detectors consisting of MCP or microsphere plate detectors and a-Si or polysilicon pixel arrays. Applications include neutron and X-ray imaging for terrestrial applications. The technology could be extended to space instrumentation for X-ray astronomy.

REVIEWS OF TOPICAL PROBLEMS: Masses of black holes in binary stellar systems

NASA Astrophysics Data System (ADS)

Cherepashchuk, Anatolii M.

1996-08-01

Mass determination methods and their results for ten black holes in X-ray binary systems are summarised. A unified interpretation of the radial velocity and optical light curves allows one to reliably justify the close binary system model and to prove the correctness of determination of the optical star mass function fv(m).The orbit plane inclination i can be estimated from an analysis of optical light curve of the system, which is due mainly to the ellipsoidal shape of the optical star (the so-called ellipticity effect). The component mass ratio q = mx/mv is obtained from information about the distance to the binary system as well as from data about rotational broadening of absorption lines in the spectrum of the optical star. These data allow one to obtain from the value of fv(m) a reliable value of the black hole mass mx or its low limit, as well as the optical star mass mv. An independent estimate of the optical star mass mv obtained from information about its spectral class and luminosity gives us test results. Additional test comes from information about the absence or presence of X-ray eclipses in the system. Effects of the non-zero dimension of the optical star, its pear-like shape, and X-ray heating on the absorption line profiles and the radial velocity curve are investigated. It is very significant that none of ten known massive (mx > 3M\\odot) X-ray sources considered as black hole candidates is an X-ray pulsar or an X-ray burster of the first kind.

Performance Test of the Next Generation X-Ray Beam Position Monitor System for The APS Upgrade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, B.; Lee, S.; Westferro, F.

The Advanced Photon Source is developing its next major upgrade (APS-U) based on the multi-bend achromat lattice. Improved beam stability is critical for the upgrade and will require keeping short-time beam angle change below 0.25 µrad and long-term angle drift below 0.6 µrad. A reliable white x-ray beam diagnostic system in the front end will be a key part of the planned beam stabilization system. This system includes an x-ray beam position monitor (XBPM) based on x-ray fluorescence (XRF) from two specially designed GlidCop A-15 absorbers, a second XBPM using XRF photons from the Exit Mask, and two white beammore » intensity monitors using XRF from the photon shutter and Compton-scattered photons from the front end beryllium window or a retractable diamond film in windowless front ends. We present orbit stability data for the first XBPM used in the feedback control during user operations, as well as test data from the second XBPM and the intensity monitors. They demonstrate that the XBPM system meets APS-U beam stability requirements.« less

Explosive vessel for coupling dynamic experiments to the X-ray beam at the Advanced Photon Source

NASA Astrophysics Data System (ADS)

Owens, Charles; Sanchez, Nathaniel; Sorensen, Christian; Jensen, Brian

2017-06-01

Recent experiments at the Advanced Photon Source have been successful in coupling gun systems to the synchrotron to take advantage of the advanced X-ray diagnostics available including X-ray diffraction and X-ray phase contrast imaging (PCI) to examine matter at extreme conditions. There are many experiments that require explosive loading capabilities, e.g. detonator and initiator dynamics, small angle X-ray scattering (SAXS), ejecta formation, and explosively driven flyer experiments. The current work highlights a new explosive vessel that was designed specifically for use at a synchrotron facility with requirements to confine up to 15 grams of explosives (TNT equivalent), couple the vessel to the X-ray beam line, and reliably position samples remotely. A description of the system and capability will be provided along with the results from qualification testing to bring the system into service (LA-UR-17-21381).

X-ray transmission microscope development

NASA Astrophysics Data System (ADS)

Kaukler, William F.; Rosenberger, Franz E.

1995-08-01

This report covers the third 6 month period, from February 28, 1995 to August 31, 1995, under this contract. The main efforts during this period were the construction of the X-ray furnace, evaluation and selection of the CCD technology for the X-ray camera, solidification experiments with Al alloys and Al-zirconia composites in the prototype furnace, evaluation of specimens for the particle pushing flight experiment - PEPSI, measurements of emitted spectra from X-ray source, testing of the high resolution X-ray test targets, and the establishment of criteria for and selection of peripheral equipment. In addition to these tasks, two presentations were prepared in this period; one for the AIAA Microgravity Symposium and another for the Gordon Conference on Gravitational Effects in Pyisico-Chemical Systems.

X-ray transmission microscope development

NASA Technical Reports Server (NTRS)

Kaukler, William F.; Rosenberger, Franz E.

1995-01-01

This report covers the third 6 month period, from February 28, 1995 to August 31, 1995, under this contract. The main efforts during this period were the construction of the X-ray furnace, evaluation and selection of the CCD technology for the X-ray camera, solidification experiments with Al alloys and Al-zirconia composites in the prototype furnace, evaluation of specimens for the particle pushing flight experiment - PEPSI, measurements of emitted spectra from X-ray source, testing of the high resolution X-ray test targets, and the establishment of criteria for and selection of peripheral equipment. In addition to these tasks, two presentations were prepared in this period; one for the AIAA Microgravity Symposium and another for the Gordon Conference on Gravitational Effects in Pyisico-Chemical Systems.

Test Operations Procedure (TOP) 5-2-521 Pyrotechnic Shock Test Procedures

DTIC Science & Technology

2007-11-20

Clipping will produce a signal that resembles a square wave . (2) Filters are used to limit the frequency bandwidth of the signal . Low pass filters...video systems permit observation of explosive items under test. c. Facilities to perform non-destructive inspections such as x-ray, ultrasonic , magna...test. (1) Accelerometers (2) Signal Conditioners (3) Digital Recording System (4) Data Processing System with hardcopy output

i RadMat: A thermo-mechanical testing system for in situ high-energy X-ray characterization of radioactive specimens

DOE PAGES

Zhang, Xuan; Xu, Chi; Wang, Leyun; ...

2017-01-27

Here, we present an in situ Radiated Materials (iRadMat) experimental module designed to interface with a servo-hydraulic load frame for X-ray measurements at beamline 1-ID at the Advanced Photon Source. This new capability allows in situ studies of radioactive specimens subject to thermo-mechanical loading using a suite of high-energy X-ray scattering and imaging techniques. The iRadMat is a radiation-shielded vacuum heating system with the sample rotation-under-load capability. We describe the design features and performances of the iRadMat and present a dataset from a 300 °C uniaxial tensile test of a neutron-irradiated pure Fe specimen to demonstrate its capabilities.

Development Of A Flash X-Ray Scanner For Stereoradiography And CT

NASA Astrophysics Data System (ADS)

Endorf, Robert J.; DiBianca, Frank A.; Fritsch, Daniel S.; Liu, Wen-Ching; Burns, Charles B.

1989-05-01

We are developing a flash x-ray scanner for stereoradiography and CT which will be able to produce a stereoradiograph in 30 to 70 ns and a complete CT scan in one microsecond. This type of imaging device will be valuable in studying high speed processes, high acceleration, and traumatic events. We have built a two channel flash x-ray system capable of producing stereo radiographs with stereo angles of from 15 to 165 degrees. The dynamic and static Miff 's for the flash x-ray system were measured and compared with similar MIT's measured for a conventional medical x-ray system. We have written and tested a stereo reconstruction algorithm to determine three dimensional space points from corresponding points in the two stereo images. To demonstrate the ability of the system to image traumatic events, a radiograph was obtained of a bone undergoing a fracture. The effects of accelerations of up to 600 g were examined on radiographs taken of human kidney tissue samples in a rapidly rotating centrifuge. Feasibility studies of CT reconstruction have been performed by making simulated Cr images of various phantoms for larger flash x-ray systems of from 8 to 29 flash x-ray tubes.

Image Processor Electronics (IPE): The High-Performance Computing System for NASA SWIFT Mission

NASA Technical Reports Server (NTRS)

Nguyen, Quang H.; Settles, Beverly A.

2003-01-01

Gamma Ray Bursts (GRBs) are believed to be the most powerful explosions that have occurred in the Universe since the Big Bang and are a mystery to the scientific community. Swift, a NASA mission that includes international participation, was designed and built in preparation for a 2003 launch to help to determine the origin of Gamma Ray Bursts. Locating the position in the sky where a burst originates requires intensive computing, because the duration of a GRB can range between a few milliseconds up to approximately a minute. The instrument data system must constantly accept multiple images representing large regions of the sky that are generated by sixteen gamma ray detectors operating in parallel. It then must process the received images very quickly in order to determine the existence of possible gamma ray bursts and their locations. The high-performance instrument data computing system that accomplishes this is called the Image Processor Electronics (IPE). The IPE was designed, built and tested by NASA Goddard Space Flight Center (GSFC) in order to meet these challenging requirements. The IPE is a small size, low power and high performing computing system for space applications. This paper addresses the system implementation and the system hardware architecture of the IPE. The paper concludes with the IPE system performance that was measured during end-to-end system testing.

An X-Ray Survey for Polar CAP Qpos in AM Herculis Systems

NASA Astrophysics Data System (ADS)

Wood, Kent

Five AM Herculis binary systems show an optical QPO that is known to be associated with magentically channeled polar cap accretion. Hard X-ray QPOs are predicted by the time-depndent hydrodynamic models. We propose to search selected AM Her systems for polar cap X-ray QPOs using the XTE PCA. Because of its large collecting area, the PCA is the only instrument that can do this job. No other accreting objects provide comparable high-quality observational diagnostics on the accretion flow. The detailed understanding of flow geometry, shock heating, ion-electron energy exchange, accretion column structure, and emission and radiative transfer mechanisms that go to make up the picture of AM Her accretion needs to be tested against X-ray timing information.

Development of cable fed flash X-ray (FXR) system

NASA Astrophysics Data System (ADS)

Menon, Rakhee; Mitra, S.; Patel, A. S.; Kumar, R.; Singh, G.; Senthil, K.; Kumar, Ranjeet; Kolge, T. S.; Roy, Amitava; Acharya, S.; Biswas, D.; Sharma, Archana

2017-08-01

Flash X-ray sources driven by pulsed power find applications in industrial radiography, and a portable X-ray source is ideal where the radiography needs to be taken at the test site. A compact and portable flash X-ray (FXR) system based on a Marx generator has been developed with the high voltage fed to the FXR tube via a cable feed-through arrangement. Hard bremsstrahlung X-rays of few tens of nanosecond duration are generated by impinging intense electron beams on an anode target of high Z material. An industrial X-ray source is developed with source size as low as 1 mm. The system can be operated from 150 kV to 450 kV peak voltages and a dose of 10 mR has been measured at 1 m distance from the source window. The modeling of the FXR source has been carried out using particle-in-cell and Monte Carlo simulations for the electron beam dynamics and X-ray generation, respectively. The angular dose profile of X-ray has been measured and compared with the simulation.

An analysis of the ArcCHECK-MR diode array's performance for ViewRay quality assurance.

PubMed

Ellefson, Steven T; Culberson, Wesley S; Bednarz, Bryan P; DeWerd, Larry A; Bayouth, John E

2017-07-01

The ArcCHECK-MR diode array utilizes a correction system with a virtual inclinometer to correct the angular response dependencies of the diodes. However, this correction system cannot be applied to measurements on the ViewRay MR-IGRT system due to the virtual inclinometer's incompatibility with the ViewRay's multiple simultaneous beams. Additionally, the ArcCHECK's current correction factors were determined without magnetic field effects taken into account. In the course of performing ViewRay IMRT quality assurance with the ArcCHECK, measurements were observed to be consistently higher than the ViewRay TPS predictions. The goals of this study were to quantify the observed discrepancies and test whether applying the current factors improves the ArcCHECK's accuracy for measurements on the ViewRay. Gamma and frequency analysis were performed on 19 ViewRay patient plans. Ion chamber measurements were performed at a subset of diode locations using a PMMA phantom with the same dimensions as the ArcCHECK. A new method for applying directionally dependent factors utilizing beam information from the ViewRay TPS was developed in order to analyze the current ArcCHECK correction factors. To test the current factors, nine ViewRay plans were altered to be delivered with only a single simultaneous beam and were measured with the ArcCHECK. The current correction factors were applied using both the new and current methods. The new method was also used to apply corrections to the original 19 ViewRay plans. It was found the ArcCHECK systematically reports doses higher than those actually delivered by the ViewRay. Application of the current correction factors by either method did not consistently improve measurement accuracy. As dose deposition and diode response have both been shown to change under the influence of a magnetic field, it can be concluded the current ArcCHECK correction factors are invalid and/or inadequate to correct measurements on the ViewRay system. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

An experimental platform for triaxial high-pressure/high-temperature testing of rocks using computed tomography

NASA Astrophysics Data System (ADS)

Glatz, Guenther; Lapene, Alexandre; Castanier, Louis M.; Kovscek, Anthony R.

2018-04-01

A conventional high-pressure/high-temperature experimental apparatus for combined geomechanical and flow-through testing of rocks is not X-ray compatible. Additionally, current X-ray transparent systems for computed tomography (CT) of cm-sized samples are limited to design temperatures below 180 °C. We describe a novel, high-temperature (>400 °C), high-pressure (>2000 psi/>13.8 MPa confining, >10 000 psi/>68.9 MPa vertical load) triaxial core holder suitable for X-ray CT scanning. The new triaxial system permits time-lapse imaging to capture the role of effective stress on fluid distribution and porous medium mechanics. System capabilities are demonstrated using ultimate compressive strength (UCS) tests of Castlegate sandstone. In this case, flooding the porous medium with a radio-opaque gas such as krypton before and after the UCS test improves the discrimination of rock features such as fractures. The results of high-temperature tests are also presented. A Uintah Basin sample of immature oil shale is heated from room temperature to 459 °C under uniaxial compression. The sample contains kerogen that pyrolyzes as temperature rises, releasing hydrocarbons. Imaging reveals the formation of stress bands as well as the evolution and connectivity of the fracture network within the sample as a function of time.

An experimental platform for triaxial high-pressure/high-temperature testing of rocks using computed tomography.

PubMed

Glatz, Guenther; Lapene, Alexandre; Castanier, Louis M; Kovscek, Anthony R

2018-04-01

A conventional high-pressure/high-temperature experimental apparatus for combined geomechanical and flow-through testing of rocks is not X-ray compatible. Additionally, current X-ray transparent systems for computed tomography (CT) of cm-sized samples are limited to design temperatures below 180 °C. We describe a novel, high-temperature (>400 °C), high-pressure (>2000 psi/>13.8 MPa confining, >10 000 psi/>68.9 MPa vertical load) triaxial core holder suitable for X-ray CT scanning. The new triaxial system permits time-lapse imaging to capture the role of effective stress on fluid distribution and porous medium mechanics. System capabilities are demonstrated using ultimate compressive strength (UCS) tests of Castlegate sandstone. In this case, flooding the porous medium with a radio-opaque gas such as krypton before and after the UCS test improves the discrimination of rock features such as fractures. The results of high-temperature tests are also presented. A Uintah Basin sample of immature oil shale is heated from room temperature to 459 °C under uniaxial compression. The sample contains kerogen that pyrolyzes as temperature rises, releasing hydrocarbons. Imaging reveals the formation of stress bands as well as the evolution and connectivity of the fracture network within the sample as a function of time.

Projection x-ray topography system at 1-BM x-ray optics test beamline at the advanced photon source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoupin, Stanislav, E-mail: sstoupin@aps.anl.gov; Liu, Zunping; Trakhtenberg, Emil

2016-07-27

Projection X-ray topography of single crystals is a classic technique for the evaluation of intrinsic crystal quality of large crystals. In this technique a crystal sample and an area detector (e.g., X-ray film) collecting intensity of a chosen crystallographic reflection are translated simultaneously across an X-ray beam collimated in the diffraction scattering plane (e.g., [1, 2]). A bending magnet beamline of a third-generation synchrotron source delivering x-ray beam with a large horizontal divergence, and therefore, a large horizontal beam size at a crystal sample position offers an opportunity to obtain X-ray topographs of large crystalline samples (e.g., 6-inch wafers) inmore » just a few exposures. Here we report projection X-ray topography system implemented recently at 1-BM beamline of the Advanced Photon Source. A selected X-ray topograph of a 6-inch wafer of 4H-SiC illustrates capabilities and limitations of the technique.« less

Fabrication and testing of a newly designed slit system for depth-resolved X-ray diffraction measurements

DOE PAGES

Sinsheimer, John; Bouet, Nathalie; Ghose, Sanjit; ...

2016-10-06

A new system of slits called `spiderweb slits' have been developed for depth-resolved powder or polycrystalline X-ray diffraction measurements. The slits act on diffracted X-rays to select a particular gauge volume of sample, while absorbing diffracted X-rays from outside of this volume. Although the slit geometry is to some extent similar to that of previously developed conical slits or spiral slits, this new design has advantages over the previous ones in use for complex heterogeneous materials and in situ and operando diffraction measurements. For example, the slits can measure a majority of any diffraction cone for any polycrystalline material, overmore » a continuous range of diffraction angles, and work for X-ray energies of tens to hundreds of kiloelectronvolts. In addition, the design is generated and optimized using ray-tracing simulations, and fabricated through laser micromachining. The first prototype was successfully tested at the X17A beamline at the National Synchrotron Light Source, and shows similar performance to simulations, demonstrating gauge volume selection for standard powders, for all diffraction peaks over angles of 2–10°. A similar, but improved, design will be implemented at the X-ray Powder Diffraction beamline at the National Synchrotron Light Source II.« less

Fabrication and testing of a newly designed slit system for depth-resolved X-ray diffraction measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sinsheimer, John; Bouet, Nathalie; Ghose, Sanjit

2016-10-06

A new system of slits called `spiderweb slits' have been developed for depth-resolved powder or polycrystalline X-ray diffraction measurements. The slits act on diffracted X-rays to select a particular gauge volume of sample, while absorbing diffracted X-rays from outside of this volume. Although the slit geometry is to some extent similar to that of previously developed conical slits or spiral slits, this new design has advantages over the previous ones in use for complex heterogeneous materials andin situandoperandodiffraction measurements. For example, the slits can measure a majority of any diffraction cone for any polycrystalline material, over a continuous range ofmore » diffraction angles, and work for X-ray energies of tens to hundreds of kiloelectronvolts. The design is generated and optimized using ray-tracing simulations, and fabricated through laser micromachining. The first prototype was successfully tested at the X17A beamline at the National Synchrotron Light Source, and shows similar performance to simulations, demonstrating gauge volume selection for standard powders, for all diffraction peaks over angles of 2–10°. A similar, but improved, design will be implemented at the X-ray Powder Diffraction beamline at the National Synchrotron Light Source II.« less

Ambient x-ray pollution assessment at inspection gates of airports- a case study of Mehrabad and Imam Khomeini Airports in Iran.

PubMed

Pourtaghi, Gholamhossein; Valipour, Firouz; Nourian, Sepideh; Mofidi, Amirabbas

2014-01-01

As a well-known, physical carcinogen, ambient X-ray pollution assessment would be of great importance in today's modern world. Accordingly, the present study was done to measure the exposure level of ambient X-ray at inspection gates of two airports in Iran. According to which, the X-ray was measured at different points of the inspection gates including closed and opened Curtain, as well as seating place of operators beside the X-ray inspection systems. The recorded data were then analyzed by "sign" and t-tests. The total average exposure level of the measured x-ray was 2.68 ± 0.73 μsv.h(-1). The measured x-ray exposure level was 2.07 ± 0.61 (μsv.h(-1)) released from RAPISCAN X-ray inspection system and 3.3 ± 1.34 (μsv.h(-1)) emitted from HEIMANN X-ray inspection system. Comparison of average x-ray doses of the systems in both airports showed that the minimum and maximum exposure levels were recorded at 1(m) far from the devices and at the entrance of the devices, respectively. The exposure levels at all measurement points were lower than the occupational exposure limit. This reveals the fact that the exposed operators are not probably at risk of adverse health effects.

X-ray backlighting of imploding aluminium liners on PTS facility

NASA Astrophysics Data System (ADS)

Yang, Qingguo; Liu, Dongbing; Mu, Jian; Huang, Xianbin; Dan, Jiakun; Xie, Xudong; Deng, Wu; Feng, Shuping; Wang, Meng; Ye, Yan; Peng, Qixian; Li, Zeren

2016-09-01

The x-ray backlighting systems, including a 1.865 keV (Si Heα line) spherically bent crystal imaging system and an ˜8.3 keV (Cu Heα line) point-projection imaging system, newly fielded on the Primary Test Stand facility are introduced and its preliminary experimental results in radiography of the aluminium (Al) liners with seeded sinusoidal perturbations are presented. The x-ray backlighter source is created using a 1 TW, 1 kJ Nd: glass high power laser, kilo-joule laser system, recently constructed at China Academy of Engineering Physics. The ablation melt and instability of the imploding Al liner outer edge under the driving current of ˜7.5 MA are successfully observed using these two backlighting systems, respectively.

Compact energy dispersive X-ray microdiffractometer for diagnosis of neoplastic tissues

NASA Astrophysics Data System (ADS)

Sosa, C.; Malezan, A.; Poletti, M. E.; Perez, R. D.

2017-08-01

An energy dispersive X-ray microdiffractometer with capillary optics has been developed for characterizing breast cancer. The employment of low divergence capillary optics helps to reduce the setup size to a few centimeters, while providing a lateral spatial resolution of 100 μm. The system angular calibration and momentum transfer resolution were assessed by a detailed study of a polycrystalline reference material. The performance of the system was tested by means of the analysis of tissue-equivalent samples previously characterized by conventional X-ray diffraction. In addition, a simplified correction model for an appropriate comparison of the diffraction spectra was developed and validated. Finally, the system was employed to evaluate normal and neoplastic human breast samples, in order to determine their X-ray scatter signatures. The initial results indicate that the use of this compact energy dispersive X-ray microdiffractometer combined with a simplified correction procedure is able to provide additional information to breast cancer diagnosis.

Noise and sensitivity of x-ray framing cameras at Nike (abstract)

NASA Astrophysics Data System (ADS)

Pawley, C. J.; Deniz, A. V.; Lehecka, T.

1999-01-01

X-ray framing cameras are the most widely used tool for radiographing density distributions in laser and Z-pinch driven experiments. The x-ray framing cameras that were developed specifically for experiments on the Nike laser system are described. One of these cameras has been coupled to a CCD camera and was tested for resolution and image noise using both electrons and x rays. The largest source of noise in the images was found to be due to low quantum detection efficiency of x-ray photons.

Analysis of particulate contamination on tape lift samples from the VETA optical surfaces

NASA Technical Reports Server (NTRS)

Germani, Mark S.

1992-01-01

Particulate contamination analysis was carried out on samples taken from the Verification Engineering Test Article (VETA) x-ray detection system. A total of eighteen tape lift samples were taken from the VETA optical surfaces. Initially, the samples were tested using a scanning electron microscope. Additionally, particle composition was determined by energy dispersive x-ray spectrometry. Results are presented in terms of particle loading per sample.

Asymmetric masks for laboratory-based X-ray phase-contrast imaging with edge illumination.

PubMed

Endrizzi, Marco; Astolfo, Alberto; Vittoria, Fabio A; Millard, Thomas P; Olivo, Alessandro

2016-05-05

We report on an asymmetric mask concept that enables X-ray phase-contrast imaging without requiring any movement in the system during data acquisition. The method is compatible with laboratory equipment, namely a commercial detector and a rotating anode tube. The only motion required is that of the object under investigation which is scanned through the imaging system. Two proof-of-principle optical elements were designed, fabricated and experimentally tested. Quantitative measurements on samples of known shape and composition were compared to theory with good agreement. The method is capable of measuring the attenuation, refraction and (ultra-small-angle) X-ray scattering, does not have coherence requirements and naturally adapts to all those situations in which the X-ray image is obtained by scanning a sample through the imaging system.

Studies of auroral X-ray imaging from high altitude spacecraft

NASA Technical Reports Server (NTRS)

Mckenzie, D. L.; Mizera, P. F.; Rice, C. J.

1980-01-01

Results of a study of techniques for imaging the aurora from a high altitude satellite at X-ray wavelengths are summarized. The X-ray observations allow the straightforward derivation of the primary auroral X-ray spectrum and can be made at all local times, day and night. Five candidate imaging systems are identified: X-ray telescope, multiple pinhole camera, coded aperture, rastered collimator, and imaging collimator. Examples of each are specified, subject to common weight and size limits which allow them to be intercompared. The imaging ability of each system is tested using a wide variety of sample spectra which are based on previous satellite observations. The study shows that the pinhole camera and coded aperture are both good auroral imaging systems. The two collimated detectors are significantly less sensitive. The X-ray telescope provides better image quality than the other systems in almost all cases, but a limitation to energies below about 4 keV prevents this system from providing the spectra data essential to deriving electron spectra, energy input to the atmosphere, and atmospheric densities and conductivities. The orbit selection requires a tradeoff between spatial resolution and duty cycle.

Mobile system for in-situ imaging of cultural objects

NASA Astrophysics Data System (ADS)

Zemlicka, J.; Jakubek, J.; Krejci, F.; Hradil, D.; Hradilova, J.; Mislerova, H.

2012-01-01

Non-invasive analytical techniques recently developed with the Timepix pixel detector have shown great potential for the inspection of objects of cultural heritage. We have developed new instrumentation and methodology for in-situ X-ray transmission radiography and X-ray fluorescence imaging and successfully tested and evaluated a mobile system for remote terrain tasks. The prototype portable imaging device comprises the radiation source tube and the spectral sensitive X-ray camera. Both components can be moreover mounted on independent motorized positioning systems allowing adaptation of irradiation geometry to the object shape. Both parts are placed onto a pair of universal portable holders (tripods). The detector is placed in a shielded box with exchangeable entrance window (beam filters and pinhole collimator). This adjustable setup allows performing in-situ measurements for both transmission and emission (XRF) radiography. The assembled system has been successfully tested in our laboratory with phantoms and real samples. The obtained and evaluated results are presented in this paper. Future work will include successive adaptation of the current system for real in-situ utilization and preparation of software allowing semi-automatic remote control of measurements.

The UCSD high energy X-ray timing experiment cosmic ray particle anticoincidence detector

NASA Technical Reports Server (NTRS)

Hink, P. L.; Rothschild, R. E.; Pelling, M. R.; Macdonald, D. R.; Gruber, D. E.

1991-01-01

The HEXTE, part of the X-Ray Timing Explorer (XTE), is designed to make high sensitivity temporal and spectral measurements of X-rays with energies between 15 and 250 keV using NaI/CsI phoswich scintillation counters. To achieve the required sensitivity it is necessary to provide anticoincidence of charged cosmic ray particles incident upon the instrument, some of which interact to produce background X-rays. The proposed cosmic ray particle anticoincidence shield detector for HEXTE uses a novel design based on plastic scintillators and wavelength-shifter bars. It consists of five segments, each with a 7 mm thick plastic scintillator, roughly 50 cm x 50 cm in size, coupled to two wavelength-shifter bars viewed by 1/2 inch photomultiplier tubes. These segments are configured into a five-sided, box-like structure around the main detector system. Results of laboratory testing of a model segment, and calculations of the expected performance of the flight segments and particle anticoincidence detector system are presented to demonstrate that the above anticoincidence detector system satisfies its scientific requirements.

X-Ray Radiography of Gas Turbine Ceramics.

DTIC Science & Technology

1979-10-20

Microfocus X-ray equipment. 1a4ihe definition of equipment concepts for a computer assisted tomography ( CAT ) system; and 4ffthe development of a CAT ...were obtained from these test coupons using Microfocus X-ray and image en- hancement techniques. A Computer Assisted Tomography ( CAT ) design concept...monitor. Computer reconstruction algorithms were investigated with respect to CAT and a preferred approach was determined. An appropriate CAT algorithm

Compact "diode-based" multi-energy soft x-ray diagnostic for NSTX.

PubMed

Tritz, K; Clayton, D J; Stutman, D; Finkenthal, M

2012-10-01

A novel and compact, diode-based, multi-energy soft x-ray (ME-SXR) diagnostic has been developed for the National Spherical Tokamak Experiment. The new edge ME-SXR system tested on NSTX consists of a set of vertically stacked diode arrays, each viewing the plasma tangentially through independent pinholes and filters providing an overlapping view of the plasma midplane which allows simultaneous SXR measurements with coarse sub-sampling of the x-ray spectrum. Using computed x-ray spectral emission data, combinations of filters can provide fast (>10 kHz) measurements of changes in the electron temperature and density profiles providing a method to "fill-in" the gaps of the multi-point Thomson scattering system.

A Compact X-Ray System for Support of High Throughput Crystallography

NASA Technical Reports Server (NTRS)

Ciszak, Ewa; Gubarev, Mikhail; Gibson, Walter M.; Joy, Marshall K.; Whitaker, Ann F. (Technical Monitor)

2001-01-01

Standard x-ray systems for crystallography rely on massive generators coupled with optics that guide X-ray beams onto the crystal sample. Optics for single-crystal diffractometry include total reflection mirrors, polycapillary optics or graded multilayer monochromators. The benefit of using polycapillary optic is that it can collect x-rays over tile greatest solid angle, and thus most efficiently, utilize the greatest portion of X-rays emitted from the Source, The x-ray generator has to have a small anode spot, and thus its size and power requirements can be substantially reduced We present the design and results from the first high flux x-ray system for crystallography that combine's a microfocus X-ray generator (40microns FWHM Spot size at a power of 45 W) and a collimating, polycapillary optic. Diffraction data collected from small test crystals with cell dimensions up to 160A (lysozyme and thaumatin) are of high quality. For example, diffraction data collected from a lysozyme crystal at RT yielded R=5.0% for data extending to 1.70A. We compare these results with measurements taken from standard crystallographic systems. Our current microfocus X-ray diffraction system is attractive for supporting crystal growth research in the standard crystallography laboratory as well as in remote, automated crystal growth laboratory. Its small volume, light-weight, and low power requirements are sufficient to have it installed in unique environments, i.e.. on-board International Space Station.

Protection of the electronic components of measuring equipment from the X-ray radiation

NASA Astrophysics Data System (ADS)

Perez Vasquez, N. O.; Kostrin, D. K.; Uhov, A. A.

2018-02-01

In this work the effect of X-ray radiation on the operation of integrated circuits of the measurement equipment is discussed. The results of the calculations of a shielding system, allowing using integrated circuits with a high degree of integration in the vicinity of the X-ray source, are shown. The results of the verification of two measurement devices that was used for more than five years in the facility for training and testing of X-ray tubes are presented.

Stacked, filtered multi-channel X-ray diode array

DOE Office of Scientific and Technical Information (OSTI.GOV)

MacNeil, Lawrence; Dutra, Eric; Raphaelian, Mark

2015-08-01

There are many types of X-ray diodes used for X-ray flux or spectroscopic measurements and for estimating the spectral shape of the VUV to soft X-ray spectrum. However, a need exists for a low-cost, robust X-ray diode to use for experiments in hostile environments on multiple platforms, and for experiments that utilize forces that may destroy the diode(s). Since the typical proposed use required a small size with a minimal single line-of-sight, a parallel array could not be used. So, a stacked, filtered multi-channel X-ray diode array was developed, called the MiniXRD. To achieve significant cost savings while maintaining robustnessmore » and ease of field setup, repair, and replacement, we designed the system to be modular. The filters were manufactured in-house and cover the range from 450 eV to 5000 eV. To achieve the line-of-sight accuracy needed, we developed mounts and laser alignment techniques. We modeled and tested elements of the diode design at NSTec Livermore Operations (NSTec / LO) to determine temporal response and dynamic range, leading to diode shape and circuitry changes to optimize impedance and charge storage. The authors fielded individual and stacked systems at several national facilities as ancillary "ride-along" diagnostics to test and improve the design usability. This paper presents the MiniXRD system performance, which supports consideration as a viable low-costalternative for multiple-channel low-energy X-ray measurements. This diode array is currently at Technical Readiness Level (TRL) 6.« less

In-line wear monitor. Final report, July 1988-April 1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pieper, K.A.; Taylor, I.J.

This report describes construction and test results of an in-line monitor for critical ferrous and nonferrous metal debris in turbine engine lubrication systems. The in-line wear monitor (ILWM) uses the X-ray fluorescence principle for detecting metal debris on a continuous basis while the engine is running. The sensor portion of the system is engine mounted and contains a radioactive X-ray source, a flow cell to direct the oil across an X-ray permeable window, a proportional counter X-ray detector and its associated preamplifier and amplifier electronics. The data acquisition electronics is mounted on the airframe and contains a microprocessor based systemmore » for inputting pulses from the sensor, classifying and counting them according to energy bands, and analyzing the data and outputting metal concentration values to the engine monitoring system. The sensor portion of the system is designed to fit on a TF41 turbine engine in place of a tube between the oil tank and the oil pump. A TF41 engine monitoring system has been modified to accept the new signals from the ILWM on spare inputs so that none of the existing functions were disturbed. The ILWM has been flow tested at various flow rates, concentration levels, oil temperatures, and aerations. The wear monitor detected iron, copper, and both iron and copper together with less than 2 ppm one sigma statistical uncertainty for 30 minute count times over the 0-50 ppm range. There was no significant effect of flow rate or aeration on accuracy. The system is developed to the point that it can be tested in an actual flight environment.« less

New optical architecture for holographic data storage system compatible with Blu-ray Disc™ system

NASA Astrophysics Data System (ADS)

Shimada, Ken-ichi; Ide, Tatsuro; Shimano, Takeshi; Anderson, Ken; Curtis, Kevin

2014-02-01

A new optical architecture for holographic data storage system which is compatible with a Blu-ray Disc™ (BD) system is proposed. In the architecture, both signal and reference beams pass through a single objective lens with numerical aperture (NA) 0.85 for realizing angularly multiplexed recording. The geometry of the architecture brings a high affinity with an optical architecture in the BD system because the objective lens can be placed parallel to a holographic medium. Through the comparison of experimental results with theory, the validity of the optical architecture was verified and demonstrated that the conventional objective lens motion technique in the BD system is available for angularly multiplexed recording. The test-bed composed of a blue laser system and an objective lens of the NA 0.85 was designed. The feasibility of its compatibility with BD is examined through the designed test-bed.

Effectiveness of the Civil Aviation Security Program.

DTIC Science & Technology

1982-10-26

12 IX. CIVIL AVIATION SECURITY ACTIONS . . . . . . 14 X . MPIANCE M EN4FOW . ........ 20 X . U . . . . . ... . . . . .. . . . 21 EXHIBITS 1...Screening Results 10. Weapon Detection Devices 11. X -Ray Baggage Inspection Systems 12. Basic Policies 13. Regulatory Impact 14. FAA Sponsored Explosive...WERE APPROVED FOR MORE THAN 200 AIRPORTS. D . TESTING WAS BEGUN ON A NEW C MPUTER PROGRAM FOR HE X -RAY ABSORPTION SYSTEM DEVELOPED TO DTECT BMBS IN

Ambient x-ray pollution assessment at inspection gates of airports- a case study of Mehrabad and Imam Khomeini Airports in Iran

PubMed Central

2014-01-01

Background As a well-known, physical carcinogen, ambient X-ray pollution assessment would be of great importance in today’s modern world. Accordingly, the present study was done to measure the exposure level of ambient X-ray at inspection gates of two airports in Iran. According to which, the X-ray was measured at different points of the inspection gates including closed and opened Curtain, as well as seating place of operators beside the X-ray inspection systems. The recorded data were then analyzed by “sign” and t-tests. Results The total average exposure level of the measured x-ray was 2.68 ± 0.73 μsv.h-1. The measured x-ray exposure level was 2.07 ± 0.61 (μsv.h-1) released from RAPISCAN X-ray inspection system and 3.3 ± 1.34 (μsv.h-1) emitted from HEIMANN X-ray inspection system. Comparison of average x-ray doses of the systems in both airports showed that the minimum and maximum exposure levels were recorded at 1(m) far from the devices and at the entrance of the devices, respectively. Conclusions The exposure levels at all measurement points were lower than the occupational exposure limit. This reveals the fact that the exposed operators are not probably at risk of adverse health effects. PMID:24955243

Optimization of a Fast Neutron Scintillator for Real-Time Pulse Shape Discrimination in the Transient Reactor Test Facility (TREAT) Hodoscope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, James T.; Thompson, Scott J.; Watson, Scott M.

We present a multi-channel, fast neutron/gamma ray detector array system that utilizes ZnS(Ag) scintillator detectors. The system employs field programmable gate arrays (FPGAs) to do real-time all digital neutron/gamma ray discrimination with pulse height and time histograms to allow count rates in excess of 1,000,000 pulses per second per channel. The system detector number is scalable in blocks of 16 channels.

High Sensitivity, One-Sided X-Ray Inspection System.

DTIC Science & Technology

1985-07-01

8217. X-Ray Imaging Quantitative NDT One-Sided Inspection Backs cat ter De laminat ions .. Nondestructive Testing (NDT) Rocket Motor Case NDT ’j 20...epoxy composites and other low atomic number materials have been detected. Wall thick nesses up to 7 cm thick have been interrogated. The results show...fiber composite rocket motor pressure vessels, the anticipated backscatter x-ray instrument will offer high sensitivity (contact delaminations have

Test results of a new detector system for gamma ray isotopic measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malcom, J.E.; Bonner, C.A.; Hurd, J.R.

1993-08-01

A new type of gamma-ray detector system for isotopic measurements has been developed. This new system, a ``Duo detector`` array, consists of two intrinsic germanium detectors, a planar followed by a coaxial mounted on the same axis within a single cryostat assembly. This configuration allows the isotopic analysis system to take advantage of spectral data results that are collected simultaneously from different gamma-ray energy regimes. Princeton Gamma Tech (PGT) produced several prototypes of this Duo detector array which were then tested by Rocky Flats personnel until the design was optimized. An application for this detector design is in automated, roboticizedmore » NDA systems such as those being developed at the Los Alamos TA-55 Plutonium Facility. The Duo detector design reduces the space necessary for the isotopic instrument by a factor of two (only one liquid nitrogen dewar is needed), and also reduces the complexity of the mechanical systems and controlling software. Data will be presented on measurements of nuclear material with a Duo detector for a wide variety of matrices. Results indicate that the maximum count rate can be increased up to 100,000 counts per second yet maintaining excellent resolution and energy rate product.« less

On-ground calibration of AGILE-GRID with a photon beam: results and lessons for the future

NASA Astrophysics Data System (ADS)

Cattaneo, P. W.; Rappoldi, A.

2013-06-01

On the AGILE satellite, there is the Gamma Ray Imaging Detector (GRID) consisting of a Silicon Tracker (ST), a Cesium Iodide Mini-Calorimeter and an Anti-Coincidence system of plastic scintillator bars. The ST needs a calibration with a γ-ray beam to validate the simulation used to calculate the detector response versus the energy and the direction of the γ rays. A tagged γ-ray beam line was designed at the Beam Test Facility of the Laboratori Nazionali of Frascati, generated by an electron beam through bremsstrahlung in a position-sensitive target. The γ-ray energy is deduced by the difference with the post-bremsstrahlung electron energy [P. W. Cattaneo, et al., Characterization of a tagged γ-ray beam line at the daΦne beam test facility, Nucl. Instr. and Meth. A 674 (2012) 55-66; P. W. Cattaneo, et al., First results about on-ground calibration of the silicon tracker for the agile satellite, Nucl. Instr. and Meth. A 630(1) (2011) 251-257.]. The electron energy is measured by a spectrometer consisting of a dipole magnet and an array of position sensitive silicon strip detectors, the Photon Tagging System (PTS). In this paper the setup and the calibration of AGILE performed in 2005 are described.

Fast frame rate rodent cardiac x-ray imaging using scintillator lens coupled to CMOS camera

NASA Astrophysics Data System (ADS)

Swathi Lakshmi, B.; Sai Varsha, M. K. N.; Kumar, N. Ashwin; Dixit, Madhulika; Krishnamurthi, Ganapathy

2017-03-01

Micro-Computed Tomography (MCT) systems for small animal imaging plays a critical role for monitoring disease progression and therapy evaluation. In this work, an in-house built micro-CT system equipped with a X-ray scintillator lens coupled to a commercial CMOS camera was used to test the feasibility of its application to Digital Subtraction Angiography (DSA). Literature has reported such studies being done with clinical X-ray tubes that can be pulsed rapidly or with rotating gantry systems, thus increasing the cost and infrastructural requirements.The feasibility of DSA was evaluated by injected Iodinated contrast agent (ICA) through the tail vein of a mouse. Projection images of the heart were acquired pre and post contrast using the high frame rate X-ray detector and processing done to visualize transit of ICA through the heart.

42 CFR 419.2 - Basis of payment.

Code of Federal Regulations, 2012 CFR

2012-10-01

... prospective payment system establishes a national payment rate, standardized for geographic wage differences...) Capital-related costs; (9) Implantable items used in connection with diagnostic X-ray tests, diagnostic laboratory tests, and other diagnostic tests; (10) Durable medical equipment that is implantable; (11...

A compact x-ray system for two-phase flow measurement

NASA Astrophysics Data System (ADS)

Song, Kyle; Liu, Yang

2018-02-01

In this paper, a compact x-ray densitometry system consisting of a 50 kV, 1 mA x-ray tube and several linear detector arrays is developed for two-phase flow measurement. The system is capable of measuring void fraction and velocity distributions with a spatial resolution of 0.4 mm per pixel and a frequency of 1000 Hz. A novel measurement model has been established for the system which takes account of the energy spectrum of x-ray photons and the beam hardening effect. An improved measurement accuracy has been achieved with this model compared with the conventional log model that has been widely used in the literature. Using this system, void fraction and velocity distributions are measured for a bubbly and a slug flow in a 25.4 mm I.D. air-water two-phase flow test loop. The measured superficial gas velocities show an error within  ±4% when compared with the gas flowmeter for both conditions.

Applications of Elpasolites as a Multimode Radiation Sensor

NASA Astrophysics Data System (ADS)

Guckes, Amber

This study consists of both computational and experimental investigations. The computational results enabled detector design selections and confirmed experimental results. The experimental results determined that the CLYC scintillation detector can be applied as a functional and field-deployable multimode radiation sensor. The computational study utilized MCNP6 code to investigate the response of CLYC to various incident radiations and to determine the feasibility of its application as a handheld multimode sensor and as a single-scintillator collimated directional detection system. These simulations include: • Characterization of the response of the CLYC scintillator to gamma-rays and neutrons; • Study of the isotopic enrichment of 7Li versus 6Li in the CLYC for optimal detection of both thermal neutrons and fast neutrons; • Analysis of collimator designs to determine the optimal collimator for the single CLYC sensor directional detection system to assay gamma rays and neutrons; Simulations of a handheld CLYC multimode sensor and a single CLYC scintillator collimated directional detection system with the optimized collimator to determine the feasibility of detecting nuclear materials that could be encountered during field operations. These nuclear materials include depleted uranium, natural uranium, low-enriched uranium, highly-enriched uranium, reactor-grade plutonium, and weapons-grade plutonium. The experimental study includes the design, construction, and testing of both a handheld CLYC multimode sensor and a single CLYC scintillator collimated directional detection system. Both were designed in the Inventor CAD software and based on results of the computational study to optimize its performance. The handheld CLYC multimode sensor is modular, scalable, low?power, and optimized for high count rates. Commercial?off?the?shelf components were used where possible in order to optimize size, increase robustness, and minimize cost. The handheld CLYC multimode sensor was successfully tested to confirm its ability for gamma-ray and neutron detection, and gamma?ray and neutron spectroscopy. The sensor utilizes wireless data transfer for possible radiation mapping and network?centric deployment. The handheld multimode sensor was tested by performing laboratory measurements with various gamma-ray sources and neutron sources. The single CLYC scintillator collimated directional detection system is portable, robust, and capable of source localization and identification. The collimator was designed based on the results of the computational study and is constructed with high density polyethylene (HDPE) and lead (Pb). The collimator design and construction allows for the directional detection of gamma rays and fast neutrons utilizing only one scintillator which is interchangeable. For this study, a CLYC-7 scintillator was used. The collimated directional detection system was tested by performing laboratory directional measurements with various gamma-ray sources, 252Cf and a 239PuBe source.

Feasibility studies on explosive detection and homeland security applications using a neutron and x-ray combined computed tomography system

NASA Astrophysics Data System (ADS)

Sinha, V.; Srivastava, A.; Lee, H. K.; Liu, X.

2013-05-01

The successful creation and operation of a neutron and X-ray combined computed tomography (NXCT) system has been demonstrated by researchers at the Missouri University of Science and Technology. The NXCT system has numerous applications in the field of material characterization and object identification in materials with a mixture of atomic numbers represented. Presently, the feasibility studies have been performed for explosive detection and homeland security applications, particularly in concealed material detection and determination of the light atomic number materials. These materials cannot be detected using traditional X-ray imaging. The new system has the capability to provide complete structural and compositional information due to the complementary nature of X-ray and neutron interactions with materials. The design of the NXCT system facilitates simultaneous and instantaneous imaging operation, promising enhanced detection capabilities of explosive materials, low atomic number materials and illicit materials for homeland security applications. In addition, a sample positioning system allowing the user to remotely and automatically manipulate the sample makes the system viable for commercial applications. Several explosives and weapon simulants have been imaged and the results are provided. The fusion algorithms which combine the data from the neutron and X-ray imaging produce superior images. This paper is a compete overview of the NXCT system for feasibility studies of explosive detection and homeland security applications. The design of the system, operation, algorithm development, and detection schemes are provided. This is the first combined neutron and X-ray computed tomography system in operation. Furthermore, the method of fusing neutron and X-ray images together is a new approach which provides high contrast images of the desired object. The system could serve as a standardized tool in nondestructive testing of many applications, especially in explosives detection and homeland security research.

High-frame-rate digital radiographic videography

NASA Astrophysics Data System (ADS)

King, Nicholas S. P.; Cverna, Frank H.; Albright, Kevin L.; Jaramillo, Steven A.; Yates, George J.; McDonald, Thomas E.; Flynn, Michael J.; Tashman, Scott

1994-10-01

High speed x-ray imaging can be an important tool for observing internal processes in a wide range of applications. In this paper we describe preliminary implementation of a system having the eventual goal of observing the internal dynamics of bone and joint reactions during loading. Two Los Alamos National Laboratory (LANL) gated and image intensified camera systems were used to record images from an x-ray image convertor tube to demonstrate the potential of high frame-rate digital radiographic videography in the analysis of bone and joint dynamics of the human body. Preliminary experiments were done at LANL to test the systems. Initial high frame-rate imaging (from 500 to 1000 frames/s) of a swinging pendulum mounted to the face of an X-ray image convertor tube demonstrated high contrast response and baseline sensitivity. The systems were then evaluated at the Motion Analysis Laboratory of Henry Ford Health Systems Bone and Joint Center. Imaging of a 9 inch acrylic disk with embedded lead markers rotating at approximately 1000 RPM, demonstrated the system response to a high velocity/high contrast target. By gating the P-20 phosphor image from the X-ray image convertor with a second image intensifier (II) and using a 100 microsecond wide optical gate through the second II, enough prompt light decay from the x-ray image convertor phosphor had taken place to achieve reduction of most of the motion blurring. Measurement of the marker velocity was made by using video frames acquired at 500 frames/s. The data obtained from both experiments successfully demonstrated the feasibility of the technique. Several key areas for improvement are discussed along with salient test results and experiment details.

The Noninvasive Measurement of X-Ray Tube Potential.

NASA Astrophysics Data System (ADS)

Ranallo, Frank Nunzio

In this thesis I briefly describe the design of clinical x-ray imaging systems and also the various methods of measuring x-ray tube potential, both invasive and noninvasive. I also discuss the meaning and usage of the quantities tube potential (kV) and peak tube potential (kVp) with reference to x-ray systems used in medical imaging. I propose that there exist several quantities which describe different important aspects of the tube potential as a function of time. These quantities are measurable and can be well defined. I have developed a list of definitions of these quantities along with suggested names and symbols. I describe the development and physical principles of a superior noninvasive method of tube potential measurement along with the instrumentation used to implement this method. This thesis research resulted in the development of several commercial kVp test devices (or "kVp Meters") for which the actual measurement procedure is simple, rapid, and reliable compared to other methods, invasive or noninvasive. These kVp test devices provide measurements with a high level of accuracy and reliability over a wide range of test conditions. They provide results which are more reliable and clinically meaningful than many other, more primary and invasive methods. The errors inherent in these new kVp test devices were investigated and methods to minimize them are discussed.

A hyperspectral X-ray computed tomography system for enhanced material identification

NASA Astrophysics Data System (ADS)

Wu, Xiaomei; Wang, Qian; Ma, Jinlei; Zhang, Wei; Li, Po; Fang, Zheng

2017-08-01

X-ray computed tomography (CT) can distinguish different materials according to their absorption characteristics. The hyperspectral X-ray CT (HXCT) system proposed in the present work reconstructs each voxel according to its X-ray absorption spectral characteristics. In contrast to a dual-energy or multi-energy CT system, HXCT employs cadmium telluride (CdTe) as the x-ray detector, which provides higher spectral resolution and separate spectral lines according to the material's photon-counter working principle. In this paper, a specimen containing ten different polymer materials randomly arranged was adopted for material identification by HXCT. The filtered back-projection algorithm was applied for image and spectral reconstruction. The first step was to sort the individual material components of the specimen according to their cross-sectional image intensity. The second step was to classify materials with similar intensities according to their reconstructed spectral characteristics. The results demonstrated the feasibility of the proposed material identification process and indicated that the proposed HXCT system has good prospects for a wide range of biomedical and industrial nondestructive testing applications.

Detective quantum efficiency: a standard test to ensure optimal detector performance and low patient exposures

NASA Astrophysics Data System (ADS)

Escartin, Terenz R.; Nano, Tomi F.; Cunningham, Ian A.

2016-03-01

The detective quantum efficiency (DQE), expressed as a function of spatial frequency, describes the ability of an x-ray detector to produce high signal-to-noise ratio (SNR) images. While regulatory and scientific communities have used the DQE as a primary metric for optimizing detector design, the DQE is rarely used by end users to ensure high system performance is maintained. Of concern is that image quality varies across different systems for the same exposures with no current measures available to describe system performance. Therefore, here we conducted an initial DQE measurement survey of clinical x-ray systems using a DQE-testing instrument to identify their range of performance. Following laboratory validation, experiments revealed that the DQE of five different systems under the same exposure level (8.0 μGy) ranged from 0.36 to 0.75 at low spatial frequencies, and 0.02 to 0.4 at high spatial frequencies (3.5 cycles/mm). Furthermore, the DQE dropped substantially with decreasing detector exposure by a factor of up to 1.5x in the lowest spatial frequency, and a factor of 10x at 3.5 cycles/mm due to the effect of detector readout noise. It is concluded that DQE specifications in purchasing decisions, combined with periodic DQE testing, are important factors to ensure patients receive the health benefits of high-quality images for low x-ray exposures.

Grazing Incidence Optics for X-rays Interferometry

NASA Technical Reports Server (NTRS)

Shipley, Ann; Zissa, David; Cash, Webster; Joy, Marshall

1999-01-01

Grazing incidence mirror parameters and constraints for x-ray interferometry are described. We present interferometer system tolerances and ray trace results used to define mirror surface accuracy requirements. Mirror material, surface figure, roughness, and geometry are evaluated based on analysis results. We also discuss mirror mount design constraints, finite element analysis, environmental issues, and solutions. Challenges associated with quantifying high accuracy mirror surface quality are addressed and test results are compared with theoretical predictions.

Coherent variability of GX 1+4

NASA Astrophysics Data System (ADS)

Nielsen, Ann-Sofie Bak; Patruno, Alessandro

2018-06-01

The accreting pulsar GX 1+4 is a symbiotic X-ray binary system with a M-type giant star companion. The system has a spin period of about 150 s and a proposed strong magnetic field of 1012-1014G. In this paper we study the coherent variability of the source and attempt to find a phase-coherent solution for the pulsar. We also test for the presence of a pulse phase - flux correlation, similar to what is observed for the accreting millisecond X-ray pulsars, in order to test whether this feature is dependent on the magnetic field strength. We find that no phase coherent solution exists which suggests that the pulsar is accreting plasma from a wind rather than an accretion disc. We also find evidence that the pulse phase is not correlated with the X-ray flux, which strengthens the idea that such relation might be present only in weak magnetic field sources like accreting millisecond pulsars.

ROBOCAL: An automated NDA (nondestructive analysis) calorimetry and gamma isotopic system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hurd, J.R.; Powell, W.D.; Ostenak, C.A.

1989-11-01

ROBOCAL, which is presently being developed and tested at Los Alamos National Laboratory, is a full-scale, prototype robotic system for remote calorimetric and gamma-ray analysis of special nuclear materials. It integrates a fully automated, multidrawer, vertical stacker-retriever system for staging unmeasured nuclear materials, and a fully automated gantry robot for computer-based selection and transfer of nuclear materials to calorimetric and gamma-ray measurement stations. Since ROBOCAL is designed for minimal operator intervention, a completely programmed user interface is provided to interact with the automated mechanical and assay systems. The assay system is designed to completely integrate calorimetric and gamma-ray data acquisitionmore » and to perform state-of-the-art analyses on both homogeneous and heterogeneous distributions of nuclear materials in a wide variety of matrices.« less

Partially coherent X-ray wavefront propagation simulations including grazing-incidence focusing optics.

PubMed

Canestrari, Niccolo; Chubar, Oleg; Reininger, Ruben

2014-09-01

X-ray beamlines in modern synchrotron radiation sources make extensive use of grazing-incidence reflective optics, in particular Kirkpatrick-Baez elliptical mirror systems. These systems can focus the incoming X-rays down to nanometer-scale spot sizes while maintaining relatively large acceptance apertures and high flux in the focused radiation spots. In low-emittance storage rings and in free-electron lasers such systems are used with partially or even nearly fully coherent X-ray beams and often target diffraction-limited resolution. Therefore, their accurate simulation and modeling has to be performed within the framework of wave optics. Here the implementation and benchmarking of a wave-optics method for the simulation of grazing-incidence mirrors based on the local stationary-phase approximation or, in other words, the local propagation of the radiation electric field along geometrical rays, is described. The proposed method is CPU-efficient and fully compatible with the numerical methods of Fourier optics. It has been implemented in the Synchrotron Radiation Workshop (SRW) computer code and extensively tested against the geometrical ray-tracing code SHADOW. The test simulations have been performed for cases without and with diffraction at mirror apertures, including cases where the grazing-incidence mirrors can be hardly approximated by ideal lenses. Good agreement between the SRW and SHADOW simulation results is observed in the cases without diffraction. The differences between the simulation results obtained by the two codes in diffraction-dominated cases for illumination with fully or partially coherent radiation are analyzed and interpreted. The application of the new method for the simulation of wavefront propagation through a high-resolution X-ray microspectroscopy beamline at the National Synchrotron Light Source II (Brookhaven National Laboratory, USA) is demonstrated.

REBOCOL (Robotic Calorimetry): An automated NDA (Nondestructive assay) calorimetry and gamma isotopic system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hurd, J.R.; Bonner, C.A.; Ostenak, C.A.

1989-01-01

ROBOCAL, which is presently being developed and tested at Los Alamos National Laboratory, is a full-scale, prototypical robotic system, for remote calorimetric and gamma-ray analysis of special nuclear materials. It integrates a fully automated, multi-drawer, vertical stacker-retriever system for staging unmeasured nuclear materials, and a fully automated gantry robot for computer-based selection and transfer of nuclear materials to calorimetric and gamma-ray measurement stations. Since ROBOCAL is designed for minimal operator intervention, a completely programmed user interface and data-base system are provided to interact with the automated mechanical and assay systems. The assay system is designed to completely integrate calorimetric andmore » gamma-ray data acquisition and to perform state-of-the-art analyses on both homogeneous and heterogeneous distributions of nuclear materials in a wide variety of matrices. 10 refs., 10 figs., 4 tabs.« less

Status and expected perfomance of the MAXI mission for the JEM/ISS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kataoka, J.; Kawai, N.

2008-12-24

MAXI (Monitor of All-sky X-ray Image) is the first payload to be attached on JEM-EF (Kibo exposed facility) of ISS. It provides an all sky X-ray image every ISS orbit. Only with a few weeks scan, MAXI is expected to make a milli-Crab X-ray all sky map excluding bright region around the sun. Thus, MAXI does not only inform X-ray novae and transients rapidly to world astronomers if once they occur, but also observes long-term variability of Galact ic and extra-Galactic X-ray sources. MAXI also provides an X-ray source catalogue at that time with diffuse cosmic X-ray background. MAXI consistsmore » of two kinds of detectors, position sensitive gas-proportional counters for 2-30 keV X-rays and CCD cameras for 0.5-10 keV X-rays. All instruments of MAXI are now in final phase of pre-launching tests of their flight modules. We are also carrying out performance tests for X-ray detectors and collimators. Data processing and analysis software including alert system on ground are being developed by mission team. In this paper we report an overview of final instruments of MAXI and capability of MAXI.« less

Design of dual energy x-ray detector for conveyor belt with steel wire ropes

NASA Astrophysics Data System (ADS)

Dai, Yue; Miao, Changyun; Rong, Feng

2009-07-01

A dual energy X-ray detector for conveyor belt with steel wire ropes is researched in the paper. Conveyor belt with steel wire ropes is one of primary transfer equipments in modern production. The traditional test methods like electromagnetic induction principle could not display inner image of steel wire ropes directly. So X-ray detection technology has used to detect the conveyor belt. However the image was not so clear by the interference of the rubber belt. Therefore, the dualenergy X-ray detection technology with subtraction method is developed to numerically remove the rubber belt from radiograph, thus improving the definition of the ropes image. The purpose of this research is to design a dual energy Xray detector that could make the operator easier to found the faulty of the belt. This detection system is composed of Xray source, detector controlled by FPGA chip, PC for running image processing system and so on. With the result of the simulating, this design really improved the capability of the staff to test the conveyor belt.

Performance verification and system integration tests of the pulse shape processor for the soft x-ray spectrometer onboard ASTRO-H

NASA Astrophysics Data System (ADS)

Takeda, Sawako; Tashiro, Makoto S.; Ishisaki, Yoshitaka; Tsujimoto, Masahiro; Seta, Hiromi; Shimoda, Yuya; Yamaguchi, Sunao; Uehara, Sho; Terada, Yukikatsu; Fujimoto, Ryuichi; Mitsuda, Kazuhisa

2014-07-01

The soft X-ray spectrometer (SXS) aboard ASTRO-H is equipped with dedicated digital signal processing units called pulse shape processors (PSPs). The X-ray microcalorimeter system SXS has 36 sensor pixels, which are operated at 50 mK to measure heat input of X-ray photons and realize an energy resolution of 7 eV FWHM in the range 0.3-12.0 keV. Front-end signal processing electronics are used to filter and amplify the electrical pulse output from the sensor and for analog-to-digital conversion. The digitized pulses from the 36 pixels are multiplexed and are sent to the PSP over low-voltage differential signaling lines. Each of two identical PSP units consists of an FPGA board, which assists the hardware logic, and two CPU boards, which assist the onboard software. The FPGA board triggers at every pixel event and stores the triggering information as a pulse waveform in the installed memory. The CPU boards read the event data to evaluate pulse heights by an optimal filtering algorithm. The evaluated X-ray photon data (including the pixel ID, energy, and arrival time information) are transferred to the satellite data recorder along with event quality information. The PSP units have been developed and tested with the engineering model (EM) and the flight model. Utilizing the EM PSP, we successfully verified the entire hardware system and the basic software design of the PSPs, including their communication capability and signal processing performance. In this paper, we show the key metrics of the EM test, such as accuracy and synchronicity of sampling clocks, event grading capability, and resultant energy resolution.

Design and experimental research on a self-magnetic pinch diode under MV

NASA Astrophysics Data System (ADS)

Pengfei, ZHANG; Yang, HU; Jiang, SUN; Yan, SONG; Jianfeng, SUN; Zhiming, YAO; Peitian, CONG; Mengtong, QIU; Aici, QIU

2018-01-01

A self-magnetic pinch diode (SMPD) integrating an anode foil-reinforced electron beam pinch focus and a small high-dose x-ray spot output was designed and optimized. An x-ray focal spot measuring system was developed in accordance with the principle of pinhole imaging. The designed SMPD and the corresponding measuring system were tested under ∼MV, with 1.75 × 2 mm2 oval x-ray spots (AWE defined) and forward directed dose 1.6 rad at 1 m. Results confirmed that the anode foil can significantly strengthen the electron beam pinch focus, and the focal spot measuring system can collect clear focal spot images. This finding indicated that the principle and method are feasible.

Preliminary testing of a prototype portable X-ray fluorescence spectrometer

NASA Technical Reports Server (NTRS)

Patten, L. L.; Anderson, N. B.; Stevenson, J. J.

1982-01-01

A portable X-ray fluorescence spectrometer for use as an analyzer in mineral resource investigative work was built and tested. The prototype battery powered spectrometer, measuring 11 by 12 by 5 inches and weighing only about 15 pounds, was designed specifically for field use. The spectrometer has two gas proportional counters and two radioactive sources, Cd (10a) and Fe (55). Preliminary field and laboratory tests on rock specimens and rock pulps have demonstrated the capability of the spectrometer to detect 33 elements to date. Characteristics of the system present some limitations, however, and further improvements are recommended.

[Problems of X-ray mammology manpower training and management].

PubMed

Rozhkova, N I

2014-01-01

The paper considers the issues of manpower training in X-ray mammology. It mentions staff shortage and no special training, which reduces the efficient activities of X-ray mammographic rooms, as well as shortage of training facilities and no unified educational programs within interdisciplinary integration, inadequate technical equipment in the training facilities, the lack of an accounting system for training higher- and mid-level health workers, as well as engineers. Emphasis is placed on that the educational programs must comply with the organizational forms of testing the specialists to be employed. The introduction of a continuous education system should be accelerated to rule out the decay period of specialists' competence.

Development of a real-time internal and external marker tracking system for particle therapy: a phantom study using patient tumor trajectory data

PubMed Central

Cho, Junsang; Cheon, Wonjoong; Ahn, Sanghee; Jung, Hyunuk; Sheen, Heesoon; Park, Hee Chul

2017-01-01

Abstract Target motion–induced uncertainty in particle therapy is more complicated than that in X-ray therapy, requiring more accurate motion management. Therefore, a hybrid motion-tracking system that can track internal tumor motion and as well as an external surrogate of tumor motion was developed. Recently, many correlation tests between internal and external markers in X-ray therapy have been developed; however, the accuracy of such internal/external marker tracking systems, especially in particle therapy, has not yet been sufficiently tested. In this article, the process of installing an in-house hybrid internal/external motion-tracking system is described and the accuracy level of tracking system was acquired. Our results demonstrated that the developed in-house external/internal combined tracking system has submillimeter accuracy, and can be clinically used as a particle therapy system as well as a simulation system for moving tumor treatment. PMID:28201522

A method to test the performance of an energy-dispersive X-ray spectrometer (EDS).

PubMed

Hodoroaba, Vasile-Dan; Procop, Mathias

2014-10-01

A test material for routine performance evaluation of energy-dispersive X-ray spectrometers (EDS) is presented. It consists of a synthetic, thick coating of C, Al, Mn, Cu, and Zr, in an elemental composition that provides interference-free characteristic X-ray lines of similar intensities at 10 kV scanning electron microscope voltage. The EDS energy resolution at the C-K, Mn-Lα, Cu-Lα, Al-K, Zr-Lα, and Mn-Kα lines, the calibration state of the energy scale, and the Mn-Lα/Mn-Kα intensity ratio as a measure for the low-energy detection efficiency are calculated by a dedicated software package from the 10 kV spectrum. Measurements at various input count rates and processor shaping times enable an estimation of the operation conditions for which the X-ray spectrum is not yet corrupted by pile-up events. Representative examples of EDS systems characterized with the test material and the related software are presented and discussed.

Scatter of X-rays on polished surfaces

NASA Technical Reports Server (NTRS)

Hasinger, G.

1981-01-01

In investigating the dispersion properties of telescope mirrors used in X-ray astronomy, the slight scattering characteristics of X-ray radiation by statistically rough surfaces were examined. The mathematics and geometry of scattering theory are described. The measurement test assembly is described and results of measurements on samples of plane mirrors are given. Measurement results are evaluated. The direct beam, the convolution of the direct beam and the scattering halo, curve fitting by the method of least squares, various autocorrelation functions, results of the fitting procedure for small scattering, and deviations in the kernel of the scattering distribution are presented. A procedure for quality testing of mirror systems through diagnosis of rough surfaces is described.

Error analysis and system optimization of non-null aspheric testing system

NASA Astrophysics Data System (ADS)

Luo, Yongjie; Yang, Yongying; Liu, Dong; Tian, Chao; Zhuo, Yongmo

2010-10-01

A non-null aspheric testing system, which employs partial null lens (PNL for short) and reverse iterative optimization reconstruction (ROR for short) technique, is proposed in this paper. Based on system modeling in ray tracing software, the parameter of each optical element is optimized and this makes system modeling more precise. Systematic error of non-null aspheric testing system is analyzed and can be categorized into two types, the error due to surface parameters of PNL in the system modeling and the rest from non-null interferometer by the approach of error storage subtraction. Experimental results show that, after systematic error is removed from testing result of non-null aspheric testing system, the aspheric surface is precisely reconstructed by ROR technique and the consideration of systematic error greatly increase the test accuracy of non-null aspheric testing system.

Combined neutron and x-ray imaging at the National Ignition Facility (invited)

DOE PAGES

Danly, C. R.; Christensen, K.; Fatherley, Valerie E.; ...

2016-10-11

X-ray and neutrons are commonly used to image Inertial Confinement Fusion implosions, providing key diagnostic information on the fuel assembly of burning DT fuel. The x-ray and neutron data provided are complementary as the production of neutrons and x-rays occur from different physical processes, but typically these two images are collected from different views with no opportunity for co-registration of the two images. Neutrons are produced where the DT fusion fuel is burning; X-rays are produced in regions corresponding to high temperatures. Processes such as mix of ablator material into the hotspot can result in increased x-ray production and decreasedmore » neutron production but can only be confidently observed if the two images are collected along the same line of sight and co-registered. To allow direct comparison of x-ray and neutron data, a Combined Neutron X-ray Imaging system has been tested at Omega and installed at the National Ignition Facility to collect an x-ray image along the currently installed neutron imaging line-of-sight. Here, this system is described, and initial results are presented along with prospects for definitive coregistration of the images.« less

Combined neutron and x-ray imaging at the National Ignition Facility (invited).

PubMed

Danly, C R; Christensen, K; Fatherley, V E; Fittinghoff, D N; Grim, G P; Hibbard, R; Izumi, N; Jedlovec, D; Merrill, F E; Schmidt, D W; Simpson, R A; Skulina, K; Volegov, P L; Wilde, C H

2016-11-01

X-ray and neutrons are commonly used to image inertial confinement fusion implosions, providing key diagnostic information on the fuel assembly of burning deuterium-tritium (DT) fuel. The x-ray and neutron data provided are complementary as the production of neutrons and x-rays occurs from different physical processes, but typically these two images are collected from different views with no opportunity for co-registration of the two images. Neutrons are produced where the DT fusion fuel is burning; X-rays are produced in regions corresponding to high temperatures. Processes such as mix of ablator material into the hotspot can result in increased x-ray production and decreased neutron production but can only be confidently observed if the two images are collected along the same line of sight and co-registered. To allow direct comparison of x-ray and neutron data, a combined neutron x-ray imaging system has been tested at Omega and installed at the National Ignition Facility to collect an x-ray image along the currently installed neutron imaging line of sight. This system is described, and initial results are presented along with prospects for definitive coregistration of the images.

X-Ray Structure determination of the Glycine Cleavage System Protein H of Mycobacterium tuberculosis Using An Inverse Compton Synchrotron X-Ray Source

PubMed Central

Abendroth, Jan; McCormick, Michael S.; Edwards, Thomas E.; Staker, Bart; Loewen, Roderick; Gifford, Martin; Rifkin, Jeff; Mayer, Chad; Guo, Wenjin; Zhang, Yang; Myler, Peter; Kelley, Angela; Analau, Erwin; Hewitt, Stephen Nakazawa; Napuli, Alberto J.; Kuhn, Peter; Ruth, Ronald D.; Stewart, Lance J.

2010-01-01

Structural genomics discovery projects require ready access to both X-ray and NMR instrumentation which support the collection of experimental data needed to solve large numbers of novel protein structures. The most productive X-ray crystal structure determination laboratories make extensive frequent use of tunable synchrotron X-ray light to solve novel structures by anomalous diffraction methods. This requires that frozen cryo-protected crystals be shipped to large government-run synchrotron facilities for data collection. In an effort to eliminate the need to ship crystals for data collection, we have developed the first laboratory-scale synchrotron light source capable of performing many of the state-of-the-art synchrotron applications in X-ray science. This Compact Light Source is a first-in-class device that uses inverse Compton scattering to generate X-rays of sufficient flux, tunable wavelength and beam size to allow high-resolution X-ray diffraction data collection from protein crystals. We report on benchmarking tests of X-ray diffraction data collection with hen egg white lysozyme, and the successful high-resolution X-ray structure determination of the Glycine cleavage system protein H from Mycobacterium tuberculosis using diffraction data collected with the Compact Light Source X-ray beam. PMID:20364333

Model-based phase-shifting interferometer

NASA Astrophysics Data System (ADS)

Liu, Dong; Zhang, Lei; Shi, Tu; Yang, Yongying; Chong, Shiyao; Miao, Liang; Huang, Wei; Shen, Yibing; Bai, Jian

2015-10-01

A model-based phase-shifting interferometer (MPI) is developed, in which a novel calculation technique is proposed instead of the traditional complicated system structure, to achieve versatile, high precision and quantitative surface tests. In the MPI, the partial null lens (PNL) is employed to implement the non-null test. With some alternative PNLs, similar as the transmission spheres in ZYGO interferometers, the MPI provides a flexible test for general spherical and aspherical surfaces. Based on modern computer modeling technique, a reverse iterative optimizing construction (ROR) method is employed for the retrace error correction of non-null test, as well as figure error reconstruction. A self-compiled ray-tracing program is set up for the accurate system modeling and reverse ray tracing. The surface figure error then can be easily extracted from the wavefront data in forms of Zernike polynomials by the ROR method. Experiments of the spherical and aspherical tests are presented to validate the flexibility and accuracy. The test results are compared with those of Zygo interferometer (null tests), which demonstrates the high accuracy of the MPI. With such accuracy and flexibility, the MPI would possess large potential in modern optical shop testing.

A Compact X-Ray System for Macromolecular Crystallography. 5

NASA Technical Reports Server (NTRS)

Gubarev, Mikhail; Ciszak, Ewa; Ponomarev, Igor; Joy, Marshall

2000-01-01

We describe the design and performance of a high flux x-ray system for macromolecular crystallography that combines a microfocus x-ray generator (40 gm FWHM spot size at a power level of 46.5Watts) and a 5.5 mm focal distance polycapillary optic. The Cu K(sub alpha) X-ray flux produced by this optimized system is 7.0 times above the X-ray flux previously reported. The X-ray flux from the microfocus system is also 3.2 times higher than that produced by the rotating anode generator equipped with a long focal distance graded multilayer monochromator (Green optic; CMF24-48-Cu6) and 30% less than that produced by the rotating anode generator with the newest design of graded multilayer monochromator (Blue optic; CMF12-38-Cu6). Both rotating anode generators operate at a power level of 5000 Watts, dissipating more than 100 times the power of our microfocus x-ray system. Diffraction data collected from small test crystals are of high quality. For example, 42,540 reflections collected at ambient temperature from a lysozyme crystal yielded R(sub sym) 5.0% for the data extending to 1.7A, and 4.8% for the complete set of data to 1.85A. The amplitudes of the reflections were used to calculate difference electron density maps that revealed positions of structurally important ions and water molecules in the crystal of lysozyme using the phases calculated from the protein model.

Detection of variable VHE γ-ray emission from the extra-galactic γ-ray binary LMC P3

NASA Astrophysics Data System (ADS)

HESS Collaboration; Abdalla, H.; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Angüner, E. O.; Arakawa, M.; Armand, C.; Arrieta, M.; Backes, M.; Balzer, A.; Barnard, M.; Becherini, Y.; Becker Tjus, J.; Berge, D.; Bernhard, S.; Bernlöhr, K.; Blackwell, R.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bonnefoy, S.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Büchele, M.; Bulik, T.; Capasso, M.; Caroff, S.; Carosi, A.; Casanova, S.; Cerruti, M.; Chakraborty, N.; Chaves, R. C. G.; Chen, A.; Chevalier, J.; Colafrancesco, S.; Condon, B.; Conrad, J.; Davids, I. D.; Decock, J.; Deil, C.; Devin, J.; deWilt, P.; Dirson, L.; Djannati-Ataï, A.; Donath, A.; Drury, L. O.'C.; Dyks, J.; Edwards, T.; Egberts, K.; Emery, G.; Ernenwein, J.-P.; Eschbach, S.; Farnier, C.; Fegan, S.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Funk, S.; Füßling, M.; Gabici, S.; Gallant, Y. A.; Garrigoux, T.; Gaté, F.; Giavitto, G.; Glawion, D.; Glicenstein, J. F.; Gottschall, D.; Grondin, M.-H.; Hahn, J.; Haupt, M.; Hawkes, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J. A.; Hofmann, W.; Hoischen, C.; Holch, T. L.; Holler, M.; Horns, D.; Ivascenko, A.; Iwasaki, H.; Jacholkowska, A.; Jamrozy, M.; Jankowsky, D.; Jankowsky, F.; Jingo, M.; Jouvin, L.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katsuragawa, M.; Katz, U.; Kerszberg, D.; Khangulyan, D.; Khélifi, B.; King, J.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Komin, Nu.; Kosack, K.; Krakau, S.; Kraus, M.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lefaucheur, J.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Leser, E.; Lohse, T.; Lorentz, M.; Liu, R.; López-Coto, R.; Lypova, I.; Malyshev, D.; Marandon, V.; Marcowith, A.; Mariaud, C.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; Meintjes, P. J.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Mohrmann, L.; Morå, K.; Moulin, E.; Murach, T.; Nakashima, S.; de Naurois, M.; Ndiyavala, H.; Niederwanger, F.; Niemiec, J.; Oakes, L.; O'Brien, P.; Odaka, H.; Ohm, S.; Ostrowski, M.; Oya, I.; Padovani, M.; Panter, M.; Parsons, R. D.; Pekeur, N. W.; Pelletier, G.; Perennes, C.; Petrucci, P.-O.; Peyaud, B.; Piel, Q.; Pita, S.; Poireau, V.; Prokhorov, D. A.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Rauth, R.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rinchiuso, L.; Romoli, C.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Saito, S.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwemmer, S.; Seglar-Arroyo, M.; Seyffert, A. S.; Shafi, N.; Shilon, I.; Shiningayamwe, K.; Simoni, R.; Sol, H.; Spanier, F.; Spir-Jacob, M.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Steppa, C.; Sushch, I.; Takahashi, T.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tibaldo, L.; Tiziani, D.; Tluczykont, M.; Trichard, C.; Tsirou, M.; Tsuji, N.; Tuffs, R.; Uchiyama, Y.; van der Walt, D. J.; van Eldik, C.; van Rensburg, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voisin, F.; Völk, H. J.; Vuillaume, T.; Wadiasingh, Z.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zaborov, D.; Zacharias, M.; Zanin, R.; Zdziarski, A. A.; Zech, A.; Zefi, F.; Ziegler, A.; Zorn, J.; Żywucka, N.

2018-03-01

Context. Recently, the high-energy (HE, 0.1-100 GeV) γ-ray emission from the object LMC P3 in the Large Magellanic Cloud (LMC) has been discovered to be modulated with a 10.3-day period, making it the first extra-galactic γ-ray binary. Aim. This work aims at the detection of very-high-energy (VHE, >100 GeV) γ-ray emission and the search for modulation of the VHE signal with the orbital period of the binary system. Methods: LMC P3 has been observed with the High Energy Stereoscopic System (H.E.S.S.); the acceptance-corrected exposure time is 100 h. The data set has been folded with the known orbital period of the system in order to test for variability of the emission. Results: VHE γ-ray emission is detected with a statistical significance of 6.4 σ. The data clearly show variability which is phase-locked to the orbital period of the system. Periodicity cannot be deduced from the H.E.S.S. data set alone. The orbit-averaged luminosity in the 1-10 TeV energy range is (1.4 ± 0.2) × 1035 erg s-1. A luminosity of (5 ± 1) × 1035 erg s-1 is reached during 20% of the orbit. HE and VHE γ-ray emissions are anti-correlated. LMC P3 is the most luminous γ-ray binary known so far.

Detection of variable VHE γ -ray emission from the extra-galactic γ -ray binary LMC P3

DOE PAGES

Abdalla, H.; Abramowski, A.; Aharonian, F.; ...

2018-02-01

Context. Recently, the high-energy (HE, 0.1–100 GeV) γ-ray emission from the object LMC P3 in the Large Magellanic Cloud (LMC) has been discovered to be modulated with a 10.3-day period, making it the first extra-galactic γ-ray binary. Aim. This work aims at the detection of very-high-energy (VHE, >100 GeV) γ-ray emission and the search for modulation of the VHE signal with the orbital period of the binary system. Methods. LMC P3 has been observed with the High Energy Stereoscopic System (H.E.S.S.); the acceptance-corrected exposure time is 100 h. The data set has been folded with the known orbital period ofmore » the system in order to test for variability of the emission. Results. VHE γ-ray emission is detected with a statistical significance of 6.4 σ. The data clearly show variability which is phase-locked to the orbital period of the system. Periodicity cannot be deduced from the H.E.S.S. data set alone. The orbit-averaged luminosity in the 1–10 TeV energy range is (1.4 ± 0.2) × 1035 erg s -1. A luminosity of (5 ± 1) × 1035 erg s -1 is reached during 20% of the orbit. HE and VHE γ-ray emissions are anti-correlated. In conclucion, LMC P3 is the most luminous γ-ray binary known so far.« less

Detection of variable VHE γ -ray emission from the extra-galactic γ -ray binary LMC P3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdalla, H.; Abramowski, A.; Aharonian, F.

Context. Recently, the high-energy (HE, 0.1–100 GeV) γ-ray emission from the object LMC P3 in the Large Magellanic Cloud (LMC) has been discovered to be modulated with a 10.3-day period, making it the first extra-galactic γ-ray binary. Aim. This work aims at the detection of very-high-energy (VHE, >100 GeV) γ-ray emission and the search for modulation of the VHE signal with the orbital period of the binary system. Methods. LMC P3 has been observed with the High Energy Stereoscopic System (H.E.S.S.); the acceptance-corrected exposure time is 100 h. The data set has been folded with the known orbital period ofmore » the system in order to test for variability of the emission. Results. VHE γ-ray emission is detected with a statistical significance of 6.4 σ. The data clearly show variability which is phase-locked to the orbital period of the system. Periodicity cannot be deduced from the H.E.S.S. data set alone. The orbit-averaged luminosity in the 1–10 TeV energy range is (1.4 ± 0.2) × 1035 erg s -1. A luminosity of (5 ± 1) × 1035 erg s -1 is reached during 20% of the orbit. HE and VHE γ-ray emissions are anti-correlated. In conclucion, LMC P3 is the most luminous γ-ray binary known so far.« less

The development and test of multi-anode microchannel array detector systems. Part 2: Soft X-ray detectors

NASA Technical Reports Server (NTRS)

Timothy, J. G.

1986-01-01

Detector systems based on the high gain microchannel plate (MCP) electron multiplier were used extensively for imaging at soft X-ray wavelengths both on the ground and in space. The latest pulse counting electronic readout systems provide zero readout noise, spatial resolutions (FWHM) of 25 microns or better and can determine the arrival times of detected photons to an accuracy of the order of 100 ns. These systems can be developed to produce detectors with active areas of 100 nm in diameter or greater. The use of CsI photocathodes produces very high detective quantum efficiencies at wavelengths between about 100 and 1A (approximately 0.1 to 10 keV) with moderate energy resolution. The operating characteristics of the different types of soft X-ray MCP detector systems are described and the prospects for future developments are discussed.

X-ray tomography system to investigate granular materials during mechanical loading

NASA Astrophysics Data System (ADS)

Athanassiadis, Athanasios G.; La Rivière, Patrick J.; Sidky, Emil; Pelizzari, Charles; Pan, Xiaochuan; Jaeger, Heinrich M.

2014-08-01

We integrate a small and portable medical x-ray device with mechanical testing equipment to enable in situ, non-invasive measurements of a granular material's response to mechanical loading. We employ an orthopedic C-arm as the x-ray source and detector to image samples mounted in the materials tester. We discuss the design of a custom rotation stage, which allows for sample rotation and tomographic reconstruction under applied compressive stress. We then discuss the calibration of the system for 3D computed tomography, as well as the subsequent image reconstruction process. Using this system to reconstruct packings of 3D-printed particles, we resolve packing features with 0.52 mm resolution in a (60 mm)3 field of view. By analyzing the performance bounds of the system, we demonstrate that the reconstructions exhibit only moderate noise.

Nondestructive Inspection System for Special Nuclear Material Using Inertial Electrostatic Confinement Fusion Neutrons and Laser Compton Scattering Gamma-Rays

NASA Astrophysics Data System (ADS)

Ohgaki, H.; Daito, I.; Zen, H.; Kii, T.; Masuda, K.; Misawa, T.; Hajima, R.; Hayakawa, T.; Shizuma, T.; Kando, M.; Fujimoto, S.

2017-07-01

A Neutron/Gamma-ray combined inspection system for hidden special nuclear materials (SNMs) in cargo containers has been developed under a program of Japan Science and Technology Agency in Japan. This inspection system consists of an active neutron-detection system for fast screening and a laser Compton backscattering gamma-ray source in coupling with nuclear resonance fluorescence (NRF) method for precise inspection. The inertial electrostatic confinement fusion device has been adopted as a neutron source and two neutron-detection methods, delayed neutron noise analysis method and high-energy neutron-detection method, have been developed to realize the fast screening system. The prototype system has been constructed and tested in the Reactor Research Institute, Kyoto University. For the generation of the laser Compton backscattering gamma-ray beam, a race track microtron accelerator has been used to reduce the size of the system. For the NRF measurement, an array of LaBr3(Ce) scintillation detectors has been adopted to realize a low-cost detection system. The prototype of the gamma-ray system has been demonstrated in the Kansai Photon Science Institute, National Institutes for Quantum and Radiological Science and Technology. By using numerical simulations based on the data taken from these prototype systems and the inspection-flow, the system designed by this program can detect 1 kg of highly enriched 235U (HEU) hidden in an empty 20-ft container within several minutes.

Illicit drug detection using energy dispersive x-ray diffraction

NASA Astrophysics Data System (ADS)

Cook, E. J.; Griffiths, J. A.; Koutalonis, M.; Gent, C.; Pani, S.; Horrocks, J. A.; George, L.; Hardwick, S.; Speller, R.

2009-05-01

Illicit drugs are imported into countries in myriad ways, including via the postal system and courier services. An automated system is required to detect drugs in parcels for which X-ray diffraction is a suitable technique as it is non-destructive, material specific and uses X-rays of sufficiently high energy to penetrate parcels containing a range of attenuating materials. A database has been constructed containing the measured powder diffraction profiles of several thousand materials likely to be found in parcels. These include drugs, cutting agents, packaging and other innocuous materials. A software model has been developed using these data to predict the diffraction profiles which would be obtained by X-ray diffraction systems with a range of suggested detector (high purity germanium, CZT and scintillation), source and collimation options. The aim of the model was to identify the most promising system geometries, which was done with the aid of multivariate analysis (MVA). The most promising systems were constructed and tested. The diffraction profiles of a range of materials have been measured and used to both validate the model and to identify the presence of drugs in sample packages.

Cargo container inspection test program at ARPA's Nonintrusive Inspection Technology Testbed

NASA Astrophysics Data System (ADS)

Volberding, Roy W.; Khan, Siraj M.

1994-10-01

An x-ray-based cargo inspection system test program is being conducted at the Advanced Research Project Agency (ARPA)-sponsored Nonintrusive Inspection Technology Testbed (NITT) located in the Port of Tacoma, Washington. The test program seeks to determine the performance that can be expected from a dual, high-energy x-ray cargo inspection system when inspecting ISO cargo containers. This paper describes an intensive, three-month, system test involving two independent test groups, one representing the criminal smuggling element and the other representing the law enforcement community. The first group, the `Red Team', prepares ISO containers for inspection at an off-site facility. An algorithm randomly selects and indicates the positions and preparation of cargoes within a container. The prepared container is dispatched to the NITT for inspection by the `Blue Team'. After in-gate processing, it is queued for examination. The Blue Team inspects the container and decides whether or not to pass the container. The shipment undergoes out-gate processing and returns to the Red Team. The results of the inspection are recorded for subsequent analysis. The test process, including its governing protocol, the cargoes, container preparation, the examination and results available at the time of submission are presented.

Principle and design of small-sized and high-definition x-ray machine

NASA Astrophysics Data System (ADS)

Zhao, Anqing

2010-10-01

The paper discusses the circuit design and working principles of VMOS PWM type 75KV10mA high frequency X-ray machine. The system mainly consists of silicon controlled rectifier, VMOS tube PWM type high-frequency and highvoltage inverter circuit, filament inverter circuit, high-voltage rectifier filter circuit and as X-ray tube. The working process can be carried out under the control of a single-chip microcomputer. Due to the small size and high resolution in imaging, the X-ray machine is mostly adopted for emergent medical diagnosis and specific circumstances where nondestructive tests are conducted.

MWPC prototyping and performance test for the STAR inner TPC upgrade

NASA Astrophysics Data System (ADS)

Shen, Fuwang; Wang, Shuai; Kong, Fangang; Bai, Shiwei; Li, Changyu; Videbæk, Flemming; Xu, Zhangbu; Zhu, Chengguang; Xu, Qinghua; Yang, Chi

2018-07-01

A new prototype of STAR inner Time Projection Chamber (iTPC) MWPC sector has been fabricated and tested in an X-ray test system. The wire chamber built at Shandong University has a wire tension precision better than 6% and wire pitch precision better than 10 μm. The gas gain uniformity and energy resolution are measured to be better than 1% (RMS) and 20% (FWHM), respectively, using an 55Fe X-ray source. The iTPC upgrade project is to replace all 24 STAR TPC inner sectors as a crucial detector upgrade for the RHIC beam energy scan phase II program. The test results show that the constructed iTPC prototype meets all project requirements.

The development and test of multi-anode microchannel array detector systems. 2: Soft X-ray detectors

NASA Technical Reports Server (NTRS)

Timothy, J. G.

1983-01-01

The techniques and procedures for producing very-large-format pulse-counting array detector systems for use in forthcoming high-energy astrophysics facilities were defined, and the structures and performance characteristics of high-sensitivity photocathodes for use at soft X-ray wavelengths between 100 and 1 A were determined. The progress made to date in each of these areas are described and the tasks that will be undertaken when the program is continued are summarized.

Overview of MAGIC results

NASA Astrophysics Data System (ADS)

Rico, Javier; MAGIC Collaboration

2016-04-01

MAGIC is a system of two 17-m diameter Cherenkov telescopes, located at the Observatorio del Roque de los Muchachos, in the Canary island La Palma (Spain). MAGIC performs astronomical observations of gamma-ray sources in the energy range between 50 GeV and 10 TeV. The first MAGIC telescope has been operating since 2004, and in 2009 the system was completed with the second one. During 2011 and 2012 the electronics for the readout system were fully upgraded, and the camera of the first telescope replaced. After that, no major hardware interventions are foreseen in the next years, and the experiment has undertaken a final period of steady astronomical observations. MAGIC studies particle acceleration in the most violent cosmic environments, such as active galactic nuclei, gamma-ray bursts, pulsars, supernova remnants or binary systems. In addition, it addresses some fundamental questions of Physics, such as the origin of Galactic cosmic rays and the nature of dark matter. Moreover, by observing the gamma-ray emission from sources at cosmological distances, we measure the intensity and evolution of the extragalactic background radiation, and perform tests of Lorentz Invariance. In this paper I present the status and some of the latest results of the MAGIC gamma-ray telescopes.

Energy and Technology Review

NASA Astrophysics Data System (ADS)

Poggio, Andrew J.

1988-10-01

This issue of Energy and Technology Review contains: Neutron Penumbral Imaging of Laser-Fusion Targets--using our new penumbral-imaging diagnostic, we have obtained the first images that can be used to measure directly the deuterium-tritium burn region in laser-driven fusion targets; Computed Tomography for Nondestructive Evaluation--various computed tomography systems and computational techniques are used in nondestructive evaluation; Three-Dimensional Image Analysis for Studying Nuclear Chromatin Structure--we have developed an optic-electronic system for acquiring cross-sectional views of cell nuclei, and computer codes to analyze these images and reconstruct the three-dimensional structures they represent; Imaging in the Nuclear Test Program--advanced techniques produce images of unprecedented detail and resolution from Nevada Test Site data; and Computational X-Ray Holography--visible-light experiments and numerically simulated holograms test our ideas about an X-ray microscope for biological research.

Development and calibration of fine collimators for the ASTRO-H Soft Gamma-ray Detector

NASA Astrophysics Data System (ADS)

Mizuno, T.; Kimura, D.; Fukazawa, Y.; Furui, S.; Goto, K.; Hayashi, T.; Kawabata, K. S.; Kawano, T.; Kitamura, Y.; Shirakawa, H.; Tanabe, T.; Makishima, K.; Nakajima, K.; Nakazawa, K.; Fukuyama, T.; Ichinohe, Y.; Ishimura, K.; Ohta, M.; Sato, T.; Takahashi, T.; Uchida, Y.; Watanabe, S.; Ishibashi, K.; Sakanobe, K.; Matsumoto, H.; Miyazawa, T.; Mori, H.; Sakai, M.; Tajima, H.

2014-07-01

The Soft Gamma-ray Detector (SGD) is a Si/CdTe Compton telescope surrounded by a thick BGO active shield and is scheduled to be onboard the ASTRO-H satellite when it is launched in 2015. The SGD covers the energy range from 40 to 600 keV with high sensitivity, which allows us to study nonthermal phenomena in the universe. The SGD uses a Compton camera with the narrow field-of-view (FOV) concept to reduce the non-Xray background (NXB) and improve the sensitivity. Since the SGD is essentially a nonimaging instrument, it also has to cope with the cosmic X-ray background (CXB) within the FOV. The SGD adopts passive shields called "fine collimators" (FCs) to restrict the FOV to <= 0.6° for low-energy photons (<= 100 keV), which reduces contamination from CXB to less than what is expected due to NXB. Although the FC concept was already adopted by the Hard X-ray Detector onboard Suzaku, FCs for the SGD are about four times larger in size and are technically more difficult to operate. We developed FCs for the SGD and confirmed that the prototypes function as required by subjecting them to an X-ray test and environmental tests, such as vibration tests. We also developed an autocollimator system, which uses visible light to determine the transmittance and the optical axis, and calibrated it against data from the X-ray test. The acceptance tests of flight models started in December 2013: five out of six FCs were deemed acceptable, and one more unit is currently being produced. The activation properties were studied based on a proton-beam test and the results were used to estimate the in-orbit NXB.

X-ray Spectral Formation In High-mass X-ray Binaries: The Case Of Vela X-1

NASA Astrophysics Data System (ADS)

Akiyama, Shizuka; Mauche, C. W.; Liedahl, D. A.; Plewa, T.

2007-05-01

We are working to develop improved models of radiatively-driven mass flows in the presence of an X-ray source -- such as in X-ray binaries, cataclysmic variables, and active galactic nuclei -- in order to infer the physical properties that determine the X-ray spectra of such systems. The models integrate a three-dimensional time-dependent hydrodynamics capability (FLASH); a comprehensive and uniform set of atomic data, improved calculations of the line force multiplier that account for X-ray photoionization and non-LTE population kinetics, and X-ray emission-line models appropriate to X-ray photoionized plasmas (HULLAC); and a Monte Carlo radiation transport code that simulates Compton scattering and recombination cascades following photoionization. As a test bed, we have simulated a high-mass X-ray binary with parameters appropriate to Vela X-1. While the orbital and stellar parameters of this system are well constrained, the physics of X-ray spectral formation is less well understood because the canonical analytical wind velocity profile of OB stars does not account for the dynamical and radiative feedback effects due to the rotation of the system and to the irradiation of the stellar wind by X-rays from the neutron star. We discuss the dynamical wind structure of Vela X-1 as determined by the FLASH simulation, where in the binary the X-ray emission features originate, and how the spatial and spectral properties of the X-ray emission features are modified by Compton scattering, photoabsorption, and fluorescent emission. This work was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48.

Silicon pore optics for the international x-ray observatory

NASA Astrophysics Data System (ADS)

Wille, E.; Wallace, K.; Bavdaz, M.; Collon, M. J.; Günther, R.; Ackermann, M.; Beijersbergen, M. W.; Riekerink, M. O.; Blom, M.; Lansdorp, B.; de Vreede, L.

2017-11-01

Lightweight X-ray Wolter optics with a high angular resolution will enable the next generation of X-ray telescopes in space. The International X-ray Observatory (IXO) requires a mirror assembly of 3 m2 effective area (at 1.5 keV) and an angular resolution of 5 arcsec. These specifications can only be achieved with a novel technology like Silicon Pore Optics, which is developed by ESA together with a consortium of European industry. Silicon Pore Optics are made of commercial Si wafers using process technology adapted from the semiconductor industry. We present the manufacturing process ranging from single mirror plates towards complete focusing mirror modules mounted in flight configuration. The performance of the mirror modules is tested using X-ray pencil beams or full X-ray illumination. In 2009, an angular resolution of 9 arcsec was achieved, demonstrating the improvement of the technology compared to 17 arcsec in 2007. Further development activities of Silicon Pore Optics concentrate on ruggedizing the mounting system and performing environmental tests, integrating baffles into the mirror modules and assessing the mass production.

Balloon Borne Instrumentation for Detection of Gamma Ray Glows

NASA Astrophysics Data System (ADS)

Sterpka, C. F.; Bagheri, M.; Dwyer, J. R.; Liu, N.; Morman, K.; Gadbois, J. L.; Bozarth, A.; Boggs, L.; Mailyan, B. G.; Nag, A.; Lazarus, S. M.; Austin, M.; Aguirre, F.; Colvin, J.; Haley, V.; Rassoul, H.

2017-12-01

Gamma-ray glows are emissions of gamma rays that last from seconds to minutes and are produced by runaway electrons in high-field regions of thunderclouds. The lightning group at the University of New Hampshire in collaboration with the Florida Institute of Technology has designed balloon-based instrumentation for flying into thunderstorms with the aim of detecting such radiation. The instrumentation includes two Geiger-Muller tubes, sensitive to both gamma rays and charged particles, and a low-power lightweight electric field mill, designed and calibrated to measure both polarity and amplitude of the vertical electric field inside the thunderstorm region. With the polarity measurement provided by the field mill, the Geiger-Muller tubes should be capable of differentiating energetic electrons from positrons. Additionally, a lead sheet is placed between the Geiger-Muller tubes to differentiate between charged particles and gamma rays. We have conducted several test flights of this system during the summer of 2017. In this study, we will present an overview of the instrumentation and discuss preliminary results from the test flights.

Development study of the X-ray scattering properties of a group of optically polished flat samples

NASA Technical Reports Server (NTRS)

Froechtenigt, J. F.

1973-01-01

A group of twelve optically polished flat samples were used to study the scattering of X-rays. The X-ray beam reflected from the twelve optical flat samples was analyzed by means of a long vacuum system of special design for these tests. The scattering measurements were made at 8.34A and 0.92 deg angle of incidence. The results for ten of the samples are comparable, the two exceptions being the fire polished samples.

Remote analysis of planetary soils: X-ray diffractometer development

NASA Technical Reports Server (NTRS)

Gregory, J. C.

1973-01-01

A system is described suitable for remote low power mineralogical analysis of lunar, planetary, or asteroid soils. It includes an X-ray diffractometer, fluorescence spectrometer, and sample preparation system. A one Curie Fe-55 source provides a monochromatic X-ray beam of 5.9 keV. Seeman-Bohlin or focusing geometry is employed in the camera, allowing peak detection to proceed simultaneously at all angles and obviating the need for moving parts. The detector system is an array of 500-600 proportional counters with a wire-spacing of 1 mm. An electronics unit comprising preamplifier, postamplifier, window discriminators, and storage flipflops requiring only 3.5 milliwatts was designed and tested. Total instrument power is less than 5 watts. Powder diffraction patterns using a flat breadboard multiwire counter were recorded.

Thermal (Silicon Diode) Data Acquisition System

NASA Technical Reports Server (NTRS)

Kegley, Jeffrey

2008-01-01

Marshall Space Flight Center's X-ray Calibration Facility (XRCF) has been performing cryogenic testing to 20 Kelvin since 1999. Two configurations for acquiring data from silicon diode temperature sensors have been implemented at the facility. The facility's environment is recorded via a data acquisition system capable of reading up to 60 silicon diodes. Test article temperature is recorded by a second data acquisition system capable of reading 150+ silicon diodes. The specifications and architecture of both systems will be presented.

Thermal (Silicon Diode) Data Acquisition Systems

NASA Technical Reports Server (NTRS)

Wright, Ernest; Kegley, Jeff

2008-01-01

Marshall Space Flight Center s X-ray Cryogenic Facility (XRCF) has been performing cryogenic testing to 20 Kelvin since 1999. Two configurations for acquiring data from silicon diode temperature sensors have been implemented at the facility. The facility's environment is recorded via a data acquisition system capable of reading up to 60 silicon diodes. Test article temperature is recorded by a second data acquisition system capable of reading 150+ silicon diodes. The specifications and architecture of both systems will be presented.

Testing of a sCVD diamond detection system in the CROCUS reactor

NASA Astrophysics Data System (ADS)

Hursin, M.; Weiss, C.; Frajtag, P.; Lamirand, V.; Perret, G.; Kavrigin, P.; Pautz, A.; Griesmayer, E.

2018-05-01

The paper describes the testing of the NEUTON detection system into CROCUS, the zero-power reactor of the École Polytechnique Fédérale de Lausanne (EPFL). NEUTON is composed of a 4 mm × 4 mm sCVD diamond detector with a 6Li converter and the associated acquisition electronics. It is developed by CIVIDEC Instrumentation GmbH. The use of a diamond detector with converter in the mixed radiation field of a nuclear reactor is challenging because these detectors are sensitive to gamma-rays, fast neutrons and thermal neutrons through conversion in 6Li . In NEUTON, the rejection of gamma-rays is achieved in real time, via the analysis of the signal pulse shape from the detector. To do so, a few signal characteristics (amplitude, area and FWHM) are recorded in the integrated Field Programmable Gate Arrays (FPGA) of the system. This treatment does not induce any dead time. Measurements in CROCUS demonstrated for the first time the capability of a system like NEUTON to detect and separate fast neutrons, thermal neutrons, and gamma-rays. The system response was shown to be linear with respect to the reactor power (up to 35W) and its thermal sensitivity was found to be (3.5± 0.2)× 10^{-5} cps/nv.

State of the Art and Development Trends of the Digital Radiography Systems for Cargo Inspection

NASA Astrophysics Data System (ADS)

Udod, V.; Van, J.; Osipov, S.; Chakhlov, S.; Temnik, A.

2016-01-01

Increasing requirements for technical parameters of inspection digital radiography systems are caused by increasing incidences of terrorism, drug trafficking and explosives via variety of transport. These requirements have determined research for new technical solutions that enable to ensure the safety of passengers and cargos in real-time. The main efforts in the analyzed method of testing are aimed at the creation of new and modernization of operated now systems of digital radiography as a whole and their main components and elements in particular. The number of these main components and elements includes sources of X-ray recording systems and transformation of radiometric information as well as algorithms and software that implements these algorithms for processing, visualization and results interpretation of inspection. Recent developments of X-ray units and betatrons used for inspection of small- and large-sized objects that are made from different materials are deserve special attention. The most effective X-ray detectors are a line and a radiometric detector matrix based on various scintillators. The most promising methods among the algorithms of material identification of testing objects are dual-energy methods. The article describes various models of digital radiography systems applied in Russia and abroad to inspection of baggage, containers, vehicles and large trucks.

Quality control and batch testing of MRPC modules for BESIII ETOF upgrade

NASA Astrophysics Data System (ADS)

Liu, Z.; Li, X.; Sun, Y. J.; Li, C.; Heng, Y. K.; Chen, T. X.; Dai, H. L.; Shao, M.; Sun, S. S.; Tang, Z. B.; Yang, R. X.; Wu, Z.; Wang, X. Z.

2017-12-01

The end-cap time-of-flight (ETOF) system for the Beijing Spectrometer III (BESIII) has been upgraded using the Multi-gap Resistive Plate Chamber (MRPC) technology (Williams et al., 1999; Li et al., 2001; Blanco et al., 2003; Fonte et al., 2013, [1-4]). A set of quality-assurance procedures has been developed to guarantee the performances of the 72 mass-produced MRPC modules installed. The cosmic ray batch testing show that the average detection efficiency of the MRPC modules is about 95%. Two different calibration methods indicate that MRPCs' time resolution can reach 60 ps in the cosmic ray test.

Development of a single-shot CCD-based data acquisition system for time-resolved X-ray photoelectron spectroscopy at an X-ray free-electron laser facility

PubMed Central

Oura, Masaki; Wagai, Tatsuya; Chainani, Ashish; Miyawaki, Jun; Sato, Hiromi; Matsunami, Masaharu; Eguchi, Ritsuko; Kiss, Takayuki; Yamaguchi, Takashi; Nakatani, Yasuhiro; Togashi, Tadashi; Katayama, Tetsuo; Ogawa, Kanade; Yabashi, Makina; Tanaka, Yoshihito; Kohmura, Yoshiki; Tamasaku, Kenji; Shin, Shik; Ishikawa, Tetsuya

2014-01-01

In order to utilize high-brilliance photon sources, such as X-ray free-electron lasers (XFELs), for advanced time-resolved photoelectron spectroscopy (TR-PES), a single-shot CCD-based data acquisition system combined with a high-resolution hemispherical electron energy analyzer has been developed. The system’s design enables it to be controlled by an external trigger signal for single-shot pump–probe-type TR-PES. The basic performance of the system is demonstrated with an offline test, followed by online core-level photoelectron and Auger electron spectroscopy in ‘single-shot image’, ‘shot-to-shot image (image-to-image storage or block storage)’ and ‘shot-to-shot sweep’ modes at soft X-ray undulator beamline BL17SU of SPring-8. In the offline test the typical repetition rate for image-to-image storage mode has been confirmed to be about 15 Hz using a conventional pulse-generator. The function for correcting the shot-to-shot intensity fluctuations of the exciting photon beam, an important requirement for the TR-PES experiments at FEL sources, has been successfully tested at BL17SU by measuring Au 4f photoelectrons with intentionally controlled photon flux. The system has also been applied to hard X-ray PES (HAXPES) in ‘ordinary sweep’ mode as well as shot-to-shot image mode at the 27 m-long undulator beamline BL19LXU of SPring-8 and also at the SACLA XFEL facility. The XFEL-induced Ti 1s core-level spectrum of La-doped SrTiO3 is reported as a function of incident power density. The Ti 1s core-level spectrum obtained at low power density is consistent with the spectrum obtained using the synchrotron source. At high power densities the Ti 1s core-level spectra show space-charge effects which are analysed using a known mean-field model for ultrafast electron packet propagation. The results successfully confirm the capability of the present data acquisition system for carrying out the core-level HAXPES studies of condensed matter induced by the XFEL. PMID:24365935

Development of a stationary chest tomosynthesis system using carbon nanotube x-ray source array

NASA Astrophysics Data System (ADS)

Shan, Jing

X-ray imaging system has shown its usefulness for providing quick and easy access of imaging in both clinic settings and emergency situations. It greatly improves the workflow in hospitals. However, the conventional radiography systems, lacks 3D information in the images. The tissue overlapping issue in the 2D projection image result in low sensitivity and specificity. Both computed tomography and digital tomosynthesis, the two conventional 3D imaging modalities, requires a complex gantry to mechanically translate the x-ray source to various positions. Over the past decade, our research group has developed a carbon nanotube (CNT) based x-ray source technology. The CNT x-ray sources allows compacting multiple x-ray sources into a single x-ray tube. Each individual x-ray source in the source array can be electronically switched. This technology allows development of stationary tomographic imaging modalities without any complex mechanical gantries. The goal of this work is to develop a stationary digital chest tomosynthesis (s-DCT) system, and implement it for a clinical trial. The feasibility of s-DCT was investigated. It is found that the CNT source array can provide sufficient x-ray output for chest imaging. Phantom images have shown comparable image qualities as conventional DCT. The s-DBT system was then used to study the effects of source array configurations and tomosynthesis image quality, and the feasibility of a physiological gated s-DCT. Using physical measures for spatial resolution, the 2D source configuration was shown to have improved depth resolution and comparable in-plane resolution. The prospective gated tomosynthesis images have shown substantially reduction of image blur associated with lung motions. The system was also used to investigate the feasibility of using s-DCT as a diagnosis and monitoring tools for cystic fibrosis patients. A new scatter reduction methods for s-DCT was also studied. Finally, a s-DCT system was constructed by retrofitting the source array to a Carestream digital radiography system. The system passed the electrical and radiation safety tests, and was installed in Marsico Hall. The patient trial started in March of 2015, and the first patient was successfully imaged.

Firing test of propellant-cracked solid motor under X-ray TV

NASA Astrophysics Data System (ADS)

Fujiwara, Tsutomu; Tanemura, Toshiharu; Itoh, Katsuya; Kakuta, Yoshiaki; Shimizu, Morio; Takahashi, Michio

This paper presents the effects of a big crack on the combustion behaviors of the scaled-down Japanese H-I upper stage motors of the National Space Development Agency (NASDA). The big crack was generated by cooling down the propellant grain below -100 C; the crack was identified and measured with the X-ray computer tomography (CT) system designed for medical use. It was found that the crack spread widely from inner bore to liner and fore-and-aft of the motor. The firing test of the propellant-cracked solid motor was performed under X-ray TV observation, and the motor exploded just after the ignition because of the abrupt chamber pressure increase due to flame propagation into the crack.

Structural control sensors for the CASES GTF

NASA Technical Reports Server (NTRS)

Davis, Hugh W.; Bukley, Angelia P.

1993-01-01

CASES (Controls, Astrophysics and Structures Experiment in Space) is a proposed space experiment to collect x-ray images of the galactic center and solar disk with unprecedented resolution. This requires precision pointing and suppression of vibrations in the long flexible structure that comprises the 32-m x-ray telescope optical bench. Two separate electro-optical sensor systems are provided for the ground test facility (GTF). The Boom Motion Tracker (BMT) measures eigenvector data for post-mission use in system identification. The Tip Displacement Sensor (TDS) measures boom tip position and is used as feedback for the closed-loop control system that stabilizes the boom. Both the BMT and the TDS have met acceptance specifications and were delivered to MSFC in February 1992. This paper describes the sensor concept, the sensor configuration as implemented in the GTF, and the results of characterization and performance testing.

Function-based design process for an intelligent ground vehicle vision system

NASA Astrophysics Data System (ADS)

Nagel, Robert L.; Perry, Kenneth L.; Stone, Robert B.; McAdams, Daniel A.

2010-10-01

An engineering design framework for an autonomous ground vehicle vision system is discussed. We present both the conceptual and physical design by following the design process, development and testing of an intelligent ground vehicle vision system constructed for the 2008 Intelligent Ground Vehicle Competition. During conceptual design, the requirements for the vision system are explored via functional and process analysis considering the flows into the vehicle and the transformations of those flows. The conceptual design phase concludes with a vision system design that is modular in both hardware and software and is based on a laser range finder and camera for visual perception. During physical design, prototypes are developed and tested independently, following the modular interfaces identified during conceptual design. Prototype models, once functional, are implemented into the final design. The final vision system design uses a ray-casting algorithm to process camera and laser range finder data and identify potential paths. The ray-casting algorithm is a single thread of the robot's multithreaded application. Other threads control motion, provide feedback, and process sensory data. Once integrated, both hardware and software testing are performed on the robot. We discuss the robot's performance and the lessons learned.

X-ray Measurements of a Thermo Scientific P385 DD Neutron Generator

DOE Office of Scientific and Technical Information (OSTI.GOV)

E.H. Seabury; D.L. Chichester; A.J. Caffrey

2001-08-01

Idaho National Laboratory is experimenting with electrical neutron generators, as potential replacements for californium-252 radioisotopic neutron sources in its PINS prompt gamma-ray neutron activation analysis (PGNAA) system for the identification of military chemical warfare agents and explosives. In addition to neutron output, we have recently measured the x-ray output of the Thermo Scientific P385 deuterium-deuterium neutron generator. X-rays are a normal byproduct from a neutron generator and depending on their intensity and energy they can interfere with gamma rays from the object under test, increase gamma-spectrometer dead time, and reduce PGNAA system throughput. The P385 x-ray energy spectrum was measuredmore » with a high-purity germanium (HPGe) detector, and a broad peak is evident at about 70 keV. To identify the source of the x-rays within the neutron generator assembly, it was scanned by collimated scintillation detectors along its long axis. At the strongest x-ray emission points, the generator also was rotated 60° between measurements. The scans show the primary source of x-ray emission from the P385 neutron generator is an area 60 mm from the neutron production target, in the vicinity of the ion source. Rotation of the neutron generator did not significantly alter the x-ray count rate, and the x-ray emission appears to be axially symmetric within the neutron generator.« less

X-ray tomography system to investigate granular materials during mechanical loading

DOE Office of Scientific and Technical Information (OSTI.GOV)

Athanassiadis, Athanasios G.; Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139; La Rivière, Patrick J.

2014-08-15

We integrate a small and portable medical x-ray device with mechanical testing equipment to enable in situ, non-invasive measurements of a granular material's response to mechanical loading. We employ an orthopedic C-arm as the x-ray source and detector to image samples mounted in the materials tester. We discuss the design of a custom rotation stage, which allows for sample rotation and tomographic reconstruction under applied compressive stress. We then discuss the calibration of the system for 3D computed tomography, as well as the subsequent image reconstruction process. Using this system to reconstruct packings of 3D-printed particles, we resolve packing featuresmore » with 0.52 mm resolution in a (60 mm){sup 3} field of view. By analyzing the performance bounds of the system, we demonstrate that the reconstructions exhibit only moderate noise.« less

A Normal Incidence X-ray Telescope (NIXT) sounding rocket payload

NASA Technical Reports Server (NTRS)

Golub, Leon

1989-01-01

Work on the High Resolution X-ray (HRX) Detector Program is described. In the laboratory and flight programs, multiple copies of a general purpose set of electronics which control the camera, signal processing and data acquisition, were constructed. A typical system consists of a phosphor convertor, image intensifier, a fiber optics coupler, a charge coupled device (CCD) readout, and a set of camera, signal processing and memory electronics. An initial rocket detector prototype camera was tested in flight and performed perfectly. An advanced prototype detector system was incorporated on another rocket flight, in which a high resolution heterojunction vidicon tube was used as the readout device for the H(alpha) telescope. The camera electronics for this tube were built in-house and included in the flight electronics. Performance of this detector system was 100 percent satisfactory. The laboratory X-ray system for operation on the ground is also described.

Temporary implementation and testing of a confocal SR- μXRF system for bone analysis at the X-ray Fluorescence beamline at Elettra

NASA Astrophysics Data System (ADS)

Perneczky, L.; Rauwolf, M.; Ingerle, D.; Eichert, D.; Brigidi, F.; Jark, W.; Bjeoumikhova, S.; Pepponi, G.; Wobrauschek, P.; Streli, C.; Turyanskaya, A.

2018-07-01

The confocal μXRF spectrometer of Atominstitut (ATI) was transported and set up at the X-ray Fluorescence beamline at Elettra - Sincrotrone Trieste. It was successfully adjusted to the incoming beam (9.2 keV). Test measurements on a free-standing Cu wire were performed to determine the size of the focused micro-beam (non-confocal mode, 56 × 35 μm2) and the size of the confocal volume (confocal mode, 41 × 24 × 34 μm2) for the Cu-K α emission. In order to test the setup's capabilities, two areas on different human bone samples were measured in confocal scanning mode. For one of the samples the comparison with a previous μ XRF measurement, obtained with a low power X-ray tube in the lab, is presented.

Low-mass X-ray binaries and gamma-ray bursts

NASA Technical Reports Server (NTRS)

Lasota, J. P.; Frank, J.; King, A. R.

1992-01-01

More than twenty years after their discovery, the nature of gamma-ray burst sources (GRBs) remains mysterious. The results from BATSE experiment aboard the Compton Observatory show however that most of the sources of gamma-ray bursts cannot be distributed in the galactic disc. The possibility that a small fraction of sites of gamma-ray bursts is of galactic disc origin cannot however be excluded. We point out that large numbers of neutron-star binaries with orbital periods of 10 hr and M dwarf companions of mass 0.2-0.3 solar mass are a natural result of the evolution of low-mass X-ray binaries (LMXBs). The numbers and physical properties of these systems suggest that some gamma-ray burst sources may be identified with this endpoint of LMXB evolution. We suggest an observational test of this hypothesis.

A Compact X-Ray System for Macromolecular Crystallography

NASA Technical Reports Server (NTRS)

Gubarev, Mikhail; Ciszak, Ewa; Ponomarev, Igor; Gibson, Walter; Joy, Marshall

2000-01-01

We describe the design and performance of a high flux x-ray system for a macromolecular crystallography that combines a microfocus x-ray generator (40 micrometer full width at half maximum spot size at a power level of 46.5 W) and a collimating polycapillary optic. The Cu Ka lpha x-ray flux produced by this optimized system through a 500,um diam orifice is 7.0 times greater than the x-ray flux previously reported by Gubarev et al. [M. Gubarev et al., J. Appl. Crystallogr. 33, 882 (2000)]. The x-ray flux from the microfocus system is also 2.6 times higher than that produced by a rotating anode generator equipped with a graded multilayer monochromator (green optic, Osmic Inc. CMF24-48-Cu6) and 40% less than that produced by a rotating anode generator with the newest design of graded multilayer monochromator (blue optic, Osmic, Inc. CMF12-38-Cu6). Both rotating anode generators operate at a power level of 5000 W, dissipating more than 100 times the power of our microfocus x-ray system. Diffraction data collected from small test crystals are of high quality. For example, 42 540 reflections collected at ambient temperature from a lysozyme crystal yielded R(sub sym)=5.0% for data extending to 1.70 A, and 4.8% for the complete set of data to 1.85 A. The amplitudes of the observed reflections were used to calculate difference electron density maps that revealed positions of structurally important ions and water molecules in the crystal of lysozyme using the phases calculated from the protein model.

Automated inspection of solder joints for surface mount technology

NASA Technical Reports Server (NTRS)

Savage, Robert M.; Park, Hyun Soo; Fan, Mark S.

1993-01-01

Researchers at NASA/GSFC evaluated various automated inspection systems (AIS) technologies using test boards with known defects in surface mount solder joints. These boards were complex and included almost every type of surface mount device typical of critical assemblies used for space flight applications: X-ray radiography; X-ray laminography; Ultrasonic Imaging; Optical Imaging; Laser Imaging; and Infrared Inspection. Vendors, representative of the different technologies, inspected the test boards with their particular machine. The results of the evaluation showed limitations of AIS. Furthermore, none of the AIS technologies evaluated proved to meet all of the inspection criteria for use in high-reliability applications. It was found that certain inspection systems could supplement but not replace manual inspection for low-volume, high-reliability, surface mount solder joints.

Inverse Compton scattering X-ray source yield optimization with a laser path folding system inserted in a pre-existent RF linac

NASA Astrophysics Data System (ADS)

Chaleil, A.; Le Flanchec, V.; Binet, A.; Nègre, J. P.; Devaux, J. F.; Jacob, V.; Millerioux, M.; Bayle, A.; Balleyguier, P.; Prazeres, R.

2016-12-01

An inverse Compton scattering source is under development at the ELSA linac of CEA, Bruyères-le-Châtel. Ultra-short X-ray pulses are produced by inverse Compton scattering of 30 ps-laser pulses by relativistic electron bunches. The source will be able to operate in single shot mode as well as in recurrent mode with 72.2 MHz pulse trains. Within this framework, an optical multipass system that multiplies the number of emitted X-ray photons in both regimes has been designed in 2014, then implemented and tested on ELSA facility in the course of 2015. The device is described from both geometrical and timing viewpoints. It is based on the idea of folding the laser optical path to pile-up laser pulses at the interaction point, thus increasing the interaction probability. The X-ray output gain measurements obtained using this system are presented and compared with calculated expectations.

Ultrahigh-speed X-ray imaging of hypervelocity projectiles

NASA Astrophysics Data System (ADS)

Miller, Stuart; Singh, Bipin; Cool, Steven; Entine, Gerald; Campbell, Larry; Bishel, Ron; Rushing, Rick; Nagarkar, Vivek V.

2011-08-01

High-speed X-ray imaging is an extremely important modality for healthcare, industrial, military and research applications such as medical computed tomography, non-destructive testing, imaging in-flight projectiles, characterizing exploding ordnance, and analyzing ballistic impacts. We report on the development of a modular, ultrahigh-speed, high-resolution digital X-ray imaging system with large active imaging area and microsecond time resolution, capable of acquiring at a rate of up to 150,000 frames per second. The system is based on a high-resolution, high-efficiency, and fast-decay scintillator screen optically coupled to an ultra-fast image-intensified CCD camera designed for ballistic impact studies and hypervelocity projectile imaging. A specially designed multi-anode, high-fluence X-ray source with 50 ns pulse duration provides a sequence of blur-free images of hypervelocity projectiles traveling at speeds exceeding 8 km/s (18,000 miles/h). This paper will discuss the design, performance, and high frame rate imaging capability of the system.

Development of x-ray imaging technique for liquid screening at airport

NASA Astrophysics Data System (ADS)

Sulaiman, Nurhani binti; Srisatit, Somyot

2016-01-01

X-ray imaging technology is a viable option to recognize flammable liquids for the purposes of aviation security. In this study, an X-ray imaging technology was developed whereby, the image viewing system was built with the use of a digital camera coupled with a gadolinium oxysulfide (GOS) fluorescent screen. The camera was equipped with a software for remote control setting of the camera via a USB cable which allows the images to be captured. The image was analysed to determine the average grey level using a software designed by Microsoft Visual Basic 6.0. The data was obtained for various densities of liquid thickness of 4.5 cm, 6.0 cm and 7.5 cm respectively for X-ray energies ranging from 70 to 200 kVp. In order to verify the reliability of the constructed calibration data, the system was tested with a few types of unknown liquids. The developed system could be conveniently employed for security screening in order to discriminate between a threat and an innocuous liquid.

Theoretical modeling of a portable x-ray tube based KXRF system to measure lead in bone

PubMed Central

Specht, Aaron J; Weisskopf, Marc G; Nie, Linda Huiling

2017-01-01

Objective K-shell x-ray fluorescence (KXRF) techniques have been used to identify health effects resulting from exposure to metals for decades, but the equipment is bulky and requires significant maintenance and licensing procedures. A portable x-ray fluorescence (XRF) device was developed to overcome these disadvantages, but introduced a measurement dependency on soft tissue thickness. With recent advances to detector technology, an XRF device utilizing the advantages of both systems should be feasible. Approach In this study, we used Monte Carlo simulations to test the feasibility of an XRF device with a high-energy x-ray tube and detector operable at room temperature. Main Results We first validated the use of Monte Carlo N-particle transport code (MCNP) for x-ray tube simulations, and found good agreement between experimental and simulated results. Then, we optimized x-ray tube settings and found the detection limit of the high-energy x-ray tube based XRF device for bone lead measurements to be 6.91 μg g−1 bone mineral using a cadmium zinc telluride detector. Significance In conclusion, this study validated the use of MCNP in simulations of x-ray tube physics and XRF applications, and demonstrated the feasibility of a high-energy x-ray tube based XRF for metal exposure assessment. PMID:28169835

Theoretical modeling of a portable x-ray tube based KXRF system to measure lead in bone.

PubMed

Specht, Aaron J; Weisskopf, Marc G; Nie, Linda Huiling

2017-03-01

K-shell x-ray fluorescence (KXRF) techniques have been used to identify health effects resulting from exposure to metals for decades, but the equipment is bulky and requires significant maintenance and licensing procedures. A portable x-ray fluorescence (XRF) device was developed to overcome these disadvantages, but introduced a measurement dependency on soft tissue thickness. With recent advances to detector technology, an XRF device utilizing the advantages of both systems should be feasible. In this study, we used Monte Carlo simulations to test the feasibility of an XRF device with a high-energy x-ray tube and detector operable at room temperature. We first validated the use of Monte Carlo N-particle transport code (MCNP) for x-ray tube simulations, and found good agreement between experimental and simulated results. Then, we optimized x-ray tube settings and found the detection limit of the high-energy x-ray tube based XRF device for bone lead measurements to be 6.91 µg g -1 bone mineral using a cadmium zinc telluride detector. In conclusion, this study validated the use of MCNP in simulations of x-ray tube physics and XRF applications, and demonstrated the feasibility of a high-energy x-ray tube based XRF for metal exposure assessment.

Measurement and simulation of a Compton suppression system for safeguards application

NASA Astrophysics Data System (ADS)

Lee, Seung Kyu; Seo, Hee; Won, Byung-Hee; Lee, Chaehun; Shin, Hee-Sung; Na, Sang-Ho; Song, Dae-Yong; Kim, Ho-Dong; Park, Geun-Il; Park, Se-Hwan

2015-11-01

Plutonium (Pu) contents in spent nuclear fuels, recovered uranium (U) or uranium/transuranium (U/TRU) products must be measured in order to secure the safeguardability of a pyroprocessing facility. Self-induced X-Ray fluorescence (XRF) and gamma-ray spectroscopy are useful techniques for determining Pu-to-U ratios and Pu isotope ratios of spent fuel. Photon measurements of spent nuclear fuel by using high-resolution spectrometers such as high-purity germanium (HPGe) detectors show a large continuum background in the low-energy region, which is due in large part to Compton scattering of energetic gamma rays. This paper proposes a Compton suppression system for reducing of the Compton continuum background. In the present study, the system was configured by using an HPGe main detector and a BGO (bismuth germanate: Bi4Ge3O12) guard detector. The system performances for gamma-ray measurement and XRF were evaluated by means of Monte Carlo simulations and measurements of the radiation source. The Monte Carlo N-Particle eXtended (MCNPX) simulations were performed using the same geometry as for the experiments, and considered, for exact results, the production of secondary electrons and photons. As a performance test of the Compton suppression system, the peak-to-Compton ratio, which is a figure of merit to evaluate the gamma-ray detection, was enhanced by a factor of three or more when the Compton suppression system was used.

X-Ray Measurements Of A Thermo Scientific P385 DD Neutron Generator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wharton, C. J.; Seabury, E. H.; Chichester, D. L.

2011-06-01

Idaho National Laboratory is experimenting with electrical neutron generators, as potential replacements for californium-252 radioisotopic neutron sources in its PINS prompt gamma-ray neutron activation analysis (PGNAA) system for the identification of military chemical warfare agents and explosives. In addition to neutron output, we have recently measured the x-ray output of the Thermo Scientific P385 deuterium-deuterium neutron generator. X rays are a normal byproduct from neutron generators, but depending on their intensity and energy, x rays can interfere with gamma rays from the object under test, increase gamma-spectrometer dead time, and reduce PGNAA system throughput. The P385 x-ray energy spectrum wasmore » measured with a high-purity germanium (HPGe) detector, and a broad peak is evident at about 70 keV. To identify the source of the x rays within the neutron generator assembly, it was scanned by collimated scintillation detectors along its long axis. At the strongest x-ray emission points, the generator also was rotated 60 deg. between measurements. The scans show the primary source of x-ray emission from the P385 neutron generator is an area 60 mm from the neutron production target, in the vicinity of the ion source. Rotation of the neutron generator did not significantly alter the x-ray count rate, and its x-ray emission appears to be axially symmetric. A thin lead shield, 3.2 mm (1/8 inch) thick, reduced the 70-keV generator x rays to negligible levels.« less

X-Ray Measurements Of A Thermo Scientific P385 DD Neutron Generator

NASA Astrophysics Data System (ADS)

Wharton, C. J.; Seabury, E. H.; Chichester, D. L.; Caffrey, A. J.; Simpson, J.; Lemchak, M.

2011-06-01

Idaho National Laboratory is experimenting with electrical neutron generators, as potential replacements for californium-252 radioisotopic neutron sources in its PINS prompt gamma-ray neutron activation analysis (PGNAA) system for the identification of military chemical warfare agents and explosives. In addition to neutron output, we have recently measured the x-ray output of the Thermo Scientific P385 deuterium-deuterium neutron generator. X rays are a normal byproduct from neutron generators, but depending on their intensity and energy, x rays can interfere with gamma rays from the object under test, increase gamma-spectrometer dead time, and reduce PGNAA system throughput. The P385 x-ray energy spectrum was measured with a high-purity germanium (HPGe) detector, and a broad peak is evident at about 70 keV. To identify the source of the x rays within the neutron generator assembly, it was scanned by collimated scintillation detectors along its long axis. At the strongest x-ray emission points, the generator also was rotated 60° between measurements. The scans show the primary source of x-ray emission from the P385 neutron generator is an area 60 mm from the neutron production target, in the vicinity of the ion source. Rotation of the neutron generator did not significantly alter the x-ray count rate, and its x-ray emission appears to be axially symmetric. A thin lead shield, 3.2 mm (1/8 inch) thick, reduced the 70-keV generator x rays to negligible levels.

4U 1820-30 as a potential test of the nonsymmetric gravitational theory of Moffat

NASA Technical Reports Server (NTRS)

Krisher, Timothy P.

1987-01-01

Recent observations of the X-ray burst source 4U 1820-30 have revealed a 685 s modulation of the luminosity. How this system could provide a stringent test of the nonsymmetric gravitational theory (NGT) of Moffat (1979), provided the observed periodicity is due to orbital motion of a binary system, is discussed. The possible orbital period change predicted by general relativity may be detectable in this system.

Studying the High Energy Gamma Ray Sky with Gamma Ray Large Area Space Telescope (GLAST)

NASA Technical Reports Server (NTRS)

Kamae, T.; Ohsugi, T.; Thompson, D. J.; Watanabe, K.

1998-01-01

Building on the success of the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory, the Gamma Ray Large Area Space Telescope (GLAST) will make a major step in the study of such subjects as blazars, gamma Ray bursts, the search for dark matter, supernova remnants, pulsars, diffuse radiation, and unidentified high energy sources. The instrument will be built on new and mature detector technologies such as silicon strip detectors, low-power low-noise LSI, and a multilevel data acquisition system. GLAST is in the research and development phase, and one full tower (of 25 total) is now being built in collaborating institutes. The prototype tower will be tested thoroughly at Stanford Linear Accelerator Center (SLAC) in the fall of 1999.

Development report: Automatic System Test and Calibration (ASTAC) equipment

NASA Technical Reports Server (NTRS)

Thoren, R. J.

1981-01-01

A microcomputer based automatic test system was developed for the daily performance monitoring of wind energy system time domain (WEST) analyzer. The test system consists of a microprocessor based controller and hybrid interface unit which are used for inputing prescribed test signals into all WEST subsystems and for monitoring WEST responses to these signals. Performance is compared to theoretically correct performance levels calculated off line on a large general purpose digital computer. Results are displayed on a cathode ray tube or are available from a line printer. Excessive drift and/or lack of repeatability of the high speed analog sections within WEST is easily detected and the malfunctioning hardware identified using this system.

[Quality assurance from the viewpoint of the x-ray film industry].

PubMed

von Volkmann, T

1992-08-01

The parameters of a film-screen-combination are listed in the directive to section 16 of the german X-ray Regulation. These parameters are determined by methods described in DIN standards and published by the manufacturer. Comparable but less precise parameters are determined in the Acceptance Test. For physical reasons it is not possible to determine the speed of an X-ray film or the intensification factor of a screen separately. The films, screens and processing chemicals delivered by the members of the manufacturer association ZVEI are kept below a deviation (expressed as relative contribution to the system speed S) of +/- 10% for the majority of products, the upper limit is +/- 15%. Poor storage and transport conditions may adversely affect the quality of X-ray films. A special labeling of the film box shall serve to guarantee safe distribution channels. The processing conditions are adjusted at the Acceptance Test according to the manufacturers recommendations. The Constancy Test of film processing serves to maintain these correct conditions. Methods deviating from the DIN-method are of limited (Bayerische method) or no value (Stuttgart method).

Organic liquid scintillation detectors for on-the-fly neutron/gamma alarming and radionuclide identification in a pedestrian radiation portal monitor

NASA Astrophysics Data System (ADS)

Paff, Marc Gerrit; Ruch, Marc L.; Poitrasson-Riviere, Alexis; Sagadevan, Athena; Clarke, Shaun D.; Pozzi, Sara

2015-07-01

We present new experimental results from a radiation portal monitor based on the use of organic liquid scintillators. The system was tested as part of a 3He-free radiation portal monitor testing campaign at the European Commission's Joint Research Centre in Ispra, Italy, in February 2014. The radiation portal monitor was subjected to a wide range of test conditions described in ANSI N42.35, including a variety of gamma-ray sources and a 20,000 n/s 252Cf source. A false alarm test tested whether radiation portal monitors ever alarmed in the presence of only natural background. The University of Michigan Detection for Nuclear Nonproliferation Group's system triggered zero false alarms in 2739 trials. It consistently alarmed on a variety of gamma-ray sources travelling at 1.2 m/s at a 70 cm source to detector distance. The neutron source was detected at speeds up to 3 m/s and in configurations with up to 8 cm of high density polyethylene shielding. The success of on-the-fly radionuclide identification varied with the gamma-ray source measured as well as with which of two radionuclide identification methods was used. Both methods used a least squares comparison between the measured pulse height distributions to library spectra to pick the best match. The methods varied in how the pulse height distributions were modified prior to the least squares comparison. Correct identification rates were as high as 100% for highly enriched uranium, but as low as 50% for 241Am. Both radionuclide identification algorithms produced mixed results, but the concept of using liquid scintillation detectors for gamma-ray and neutron alarming in radiation portal monitor was validated.

Development of a real-time internal and external marker tracking system for particle therapy: a phantom study using patient tumor trajectory data.

PubMed

Cho, Junsang; Cheon, Wonjoong; Ahn, Sanghee; Jung, Hyunuk; Sheen, Heesoon; Park, Hee Chul; Han, Youngyih

2017-09-01

Target motion-induced uncertainty in particle therapy is more complicated than that in X-ray therapy, requiring more accurate motion management. Therefore, a hybrid motion-tracking system that can track internal tumor motion and as well as an external surrogate of tumor motion was developed. Recently, many correlation tests between internal and external markers in X-ray therapy have been developed; however, the accuracy of such internal/external marker tracking systems, especially in particle therapy, has not yet been sufficiently tested. In this article, the process of installing an in-house hybrid internal/external motion-tracking system is described and the accuracy level of tracking system was acquired. Our results demonstrated that the developed in-house external/internal combined tracking system has submillimeter accuracy, and can be clinically used as a particle therapy system as well as a simulation system for moving tumor treatment. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

Commissioning and quality assurance of an integrated system for patient positioning and setup verification in particle therapy.

PubMed

Pella, A; Riboldi, M; Tagaste, B; Bianculli, D; Desplanques, M; Fontana, G; Cerveri, P; Seregni, M; Fattori, G; Orecchia, R; Baroni, G

2014-08-01

In an increasing number of clinical indications, radiotherapy with accelerated particles shows relevant advantages when compared with high energy X-ray irradiation. However, due to the finite range of ions, particle therapy can be severely compromised by setup errors and geometric uncertainties. The purpose of this work is to describe the commissioning and the design of the quality assurance procedures for patient positioning and setup verification systems at the Italian National Center for Oncological Hadrontherapy (CNAO). The accuracy of systems installed in CNAO and devoted to patient positioning and setup verification have been assessed using a laser tracking device. The accuracy in calibration and image based setup verification relying on in room X-ray imaging system was also quantified. Quality assurance tests to check the integration among all patient setup systems were designed, and records of daily QA tests since the start of clinical operation (2011) are presented. The overall accuracy of the patient positioning system and the patient verification system motion was proved to be below 0.5 mm under all the examined conditions, with median values below the 0.3 mm threshold. Image based registration in phantom studies exhibited sub-millimetric accuracy in setup verification at both cranial and extra-cranial sites. The calibration residuals of the OTS were found consistent with the expectations, with peak values below 0.3 mm. Quality assurance tests, daily performed before clinical operation, confirm adequate integration and sub-millimetric setup accuracy. Robotic patient positioning was successfully integrated with optical tracking and stereoscopic X-ray verification for patient setup in particle therapy. Sub-millimetric setup accuracy was achieved and consistently verified in daily clinical operation.

MWPC prototyping and performance test for the STAR inner TPC upgrade

DOE PAGES

Shen, Fuwang; Wang, Shuai; Kong, Fangang; ...

2018-04-16

A new prototype of STAR inner Time Projection Chamber (iTPC) MWPC sector has been fabricated and tested in an X-ray test system. The wire chamber built at Shandong University has a wire tension precision better than 6% and wire pitch precision better than 10 μm. The gas gain uniformity and energy resolution are measured to be better than 1% (RMS) and 20% (FWHM), respectively, using an 55Fe X-ray source. The iTPC upgrade project is to replace all 24 STAR TPC inner sectors as a crucial detector upgrade for the RHIC beam energy scan phase II program. Furthermore, the test resultsmore » show that the constructed iTPC prototype meets all project requirements.« less

MWPC prototyping and performance test for the STAR inner TPC upgrade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Fuwang; Wang, Shuai; Kong, Fangang

A new prototype of STAR inner Time Projection Chamber (iTPC) MWPC sector has been fabricated and tested in an X-ray test system. The wire chamber built at Shandong University has a wire tension precision better than 6% and wire pitch precision better than 10 μm. The gas gain uniformity and energy resolution are measured to be better than 1% (RMS) and 20% (FWHM), respectively, using an 55Fe X-ray source. The iTPC upgrade project is to replace all 24 STAR TPC inner sectors as a crucial detector upgrade for the RHIC beam energy scan phase II program. Furthermore, the test resultsmore » show that the constructed iTPC prototype meets all project requirements.« less

X-ray angiography systems.

PubMed

1993-11-01

Despite the emergence of several alternative angiographic imaging techniques (i.e., magnetic resonance imaging, computed tomography, and ultrasound angiography), x-ray angiography remains the predominant vascular imaging modality, generating over $4 billion in revenue a year in U.S. hospitals. In this issue, we provide a brief overview of the various angiographic imaging techniques, comparing them with x-ray angiography, and discuss the clinical aspects of x-ray vascular imaging, including catheterization and clinical applications. Clinical, cost, usage, and legal issues related to contrast media are discussed in "Contrast Media: Ionic versus Nonionic and Low-osmolality Agents." We also provide a technical overview and selection guidance for a basic x-ray angiography imaging system, including the gantry and table system, x-ray generator, x-ray tube, image intensifier, video camera and display monitors, image-recording devices, and digital acquisition and processing systems. This issue also contains our Evaluation of the GE Advantx L/C cardiac angiography system and the GE Advantx AFM general-purpose angiography system; the AFM can be used for peripheral, pulmonary, and cerebral vascular studied, among others, and can also be configured for cardiac angiography. Many features of the Advantx L/C system, including generator characteristics and ease of use, also apply to the Advantx AFM as configured for cardiac angiography. Our ratings are based on the systems' ability to provide the best possible image quality for diagnosis and therapy while minimizing patient and personnel exposure to radiation, as well as its ability to minimize operator effort and inconvenience. Both units are rated Acceptable. In the Guidance Section, "Radiation Safety and Protection," we discuss the importance of keeping patient and personnel exposures to radiation as low as reasonably possible, especially in procedures such as cardiac catheterization, angiographic imaging for special procedures, and interventional radiology, which produce among the highest radiation exposure of all x-ray imaging techniques. We also provide recommendations for minimizing personnel and patient exposures to radiation. For more information about x-ray angiography systems and similar devices, as well as for additional perspectives on which we based this study, see the following Health Devices Evaluations: "Mobile C-arm Units" (19[8], August 1990) and "Noninvasive Electronic Quality Control Devices for X-ray Generator Testing" (21[6-7], June-July 1992).(ABSTRACT TRUNCATED AT 400 WORDS)

Equatorial secondary cosmic ray observatory to study space weather and terrestrial events

NASA Astrophysics Data System (ADS)

Vichare, Geeta; Bhaskar, Ankush; Datar, Gauri; Raghav, Anil; Nair, K. U.; Selvaraj, C.; Ananthi, M.; Sinha, A. K.; Paranjape, M.; Gawade, T.; Anil Kumar, C. P.; Panneerselvam, C.; Sathishkumar, S.; Gurubaran, S.

2018-05-01

Recently, equatorial secondary cosmic ray observatory has been established at Equatorial Geophysical Research Laboratory (EGRL), Tirunelveli, (Geographic Coordinates: 8.71°N, 77.76°E), to study secondary cosmic rays (SCR) produced due to the interaction of primary cosmic rays with the Earth's atmosphere. EGRL is a regional center of Indian Institute of Geomagnetism (IIG), located near the equator in the Southern part of India. Two NaI(Tl) scintillation detectors are installed inside the temperature controlled environment. One detector is cylindrical in shape of size 7.62 cm × 7.62 cm and another one is rectangular cuboid of 10.16 cm × 10.16 cm × 40.64 cm size. Besides NaI(Tl) detectors, various other research facilities such as the Geomagnetic observatory, Medium Frequency Radar System, Digital Ionosonde, All-sky airglow imager, Atmospheric electricity laboratory to measure the near-Earth atmospheric electric fields are also available at EGRL. With the accessibility of multi- instrument facilities, the objective is set to understand the relationship between SCR and various atmospheric and ionospheric processes, during space weather and terrestrial events. For gamma-ray spectroscopy, it is important to test the performance of the NaI(Tl) scintillation detectors and to calibrate the gamma-ray spectrum in terms of energy. The present article describes the details of the experimental setup installed near the equator to study cosmic rays, along with the performance testing and calibration of the detectors under various conditions. A systematic shift in the gain is observed with varying temperature of the detector system. It is found that the detector's response to the variations in the temperature is not just linear or non-linear type, but it depends on the history of the variation, indicating temperature hysteresis effects on NaI detector and PMT system. This signifies the importance of isothermal environment while studying SCR flux using NaI(Tl) detectors, especially for the experiments conducted during daytime such as solar eclipses etc.

Control and acquisition system of a space instrument for cosmic ray measurement

NASA Astrophysics Data System (ADS)

Prieto, M.; Martín, C.; Quesada, M.; Meziat, D.; Medina, J.; Sánchez, S.; Rodríguez-Frías, M. D.

2000-04-01

The PESCA Instrument Control and Acquisition System (PICAS) design, building and tests are presented. The purpose of the PESCA instrument is the study of the Solar Energetic Particles and the Anomalous Cosmic Rays. It is, therefore, a satellite on-board instrument. The PICAS is basically a computer, composed of a microprocessor with a memory block and a set of interfaces for the communication with the rest of the instrument and the satellite. The PICAS manages all the comunication processes with the satellite, that comprises the order reception from the ground station, and the telemetry sending, that includes scientific data and housekeeping data. By means of telecommands, the PICAS is completely controllable from the ground. The PICAS is also a reliable data acquisition system that guarantees the correct reception of the Cosmic Rays data collected in the ground.

Vehicle and cargo inspection system

NASA Astrophysics Data System (ADS)

Verbinski, Victor V.; Orphan, Victor J.

1997-02-01

Vehicle and Cargo Inspection System (VACIS) is comprised of a 1 Curie 137Cs gamma-ray source in a shield and collimator which produces a fan-shaped beam designed to intercept a vertical array of gama-ray detectors contained in a tower structure. The source and detector modules straddle the vehicle or container being inspected and are mounted on self-propelled trolleys which travel in synchronization along two parallel tracks covering the length of the scanned object. The signals from the gamma-ray detector array are processed and displayed so as to produce a 2D gamma-radiographic image of the object. Testing of the system on a variety of empty and lightly-loaded vehicles and containers has demonstrated the effectiveness of VACIS in detecting hidden contraband. For example, a small sample of cocaine only 1.5 inches thick was readily detected in a container.

In-flight performance of the soft x-ray spectrometer detector system on Astro-H

NASA Astrophysics Data System (ADS)

Porter, Frederick S.; Boyce, Kevin R.; Chiao, Meng P.; Eckart, Megan E.; Fujimoto, Ryuichi; Ishisaki, Yoshitaka; Kilbourne, Caroline Anne; Leutenegger, Maurice A.; McCammon, Daniel; Mitsuda, Kazuhisa; Sato, Kosuke; Seta, Hiromi; Sawada, Makoto; Sneiderman, Gary A.; Szymkowiak, Andrew E.; Takei, Yoh; Tashiro, Makoto S.; Tsujimoto, Masahiro; Watanabe, Tomomi; Yamada, Shinya

2018-01-01

The soft x-ray spectrometer (SXS) instrument was launched aboard the Astro-H (Hitomi) observatory on February 17, 2016. The SXS is based on a high-sensitivity x-ray calorimeter detector system that has been successfully deployed in many ground and suborbital spectrometers. The instrument was to provide essential diagnostics for nearly every class of x-ray emitting objects from the atmosphere of Jupiter to the outskirts of galaxy clusters, without degradation for spatially extended objects. The SXS detector system consisted of a 36-pixel cryogenic microcalorimeter array operated at a heat sink temperature of 50 mK. In preflight testing, the detector system demonstrated a resolving power of better than 1300 at 6 keV with a simultaneous bandpass from below 0.3 keV to above 12 keV with a timing precision better than 100 μs. In addition, a solid-state anticoincidence detector was placed directly behind the detector array for background suppression. The detector error budget included the measured interference from the SXS cooling system and the spacecraft. Additional margin for on-orbit gain stability and on-orbit spacecraft interference were also included predicting an on-orbit performance that meets or exceeds the 7-eV FWHM at 6-keV requirement. The actual on-orbit spectral resolution was better than 5 eV FWHM at 6 keV, easily satisfying the instrument requirement. Here, we discuss the actual on-orbit performance of the SXS detector system and compare this to performance in preflight testing and the on-orbit predictions. We will also discuss the on-orbit gain stability, additional on-orbit interference, and measurements of the on-orbit background.

Segmented X-Ray Optics for Future Space Telescopes

NASA Technical Reports Server (NTRS)

McClelland, Ryan S.

2013-01-01

Lightweight and high resolution mirrors are needed for future space-based X-ray telescopes to achieve advances in high-energy astrophysics. The slumped glass mirror technology in development at NASA GSFC aims to build X-ray mirror modules with an area to mass ratio of approx.17 sq cm/kg at 1 keV and a resolution of 10 arc-sec Half Power Diameter (HPD) or better at an affordable cost. As the technology nears the performance requirements, additional engineering effort is needed to ensure the modules are compatible with space-flight. This paper describes Flight Mirror Assembly (FMA) designs for several X-ray astrophysics missions studied by NASA and defines generic driving requirements and subsequent verification tests necessary to advance technology readiness for mission implementation. The requirement to perform X-ray testing in a horizontal beam, based on the orientation of existing facilities, is particularly burdensome on the mirror technology, necessitating mechanical over-constraint of the mirror segments and stiffening of the modules in order to prevent self-weight deformation errors from dominating the measured performance. This requirement, in turn, drives the mass and complexity of the system while limiting the testable angular resolution. Design options for a vertical X-ray test facility alleviating these issues are explored. An alternate mirror and module design using kinematic constraint of the mirror segments, enabled by a vertical test facility, is proposed. The kinematic mounting concept has significant advantages including potential for higher angular resolution, simplified mirror integration, and relaxed thermal requirements. However, it presents new challenges including low vibration modes and imperfections in kinematic constraint. Implementation concepts overcoming these challenges are described along with preliminary test and analysis results demonstrating the feasibility of kinematically mounting slumped glass mirror segments.

The soft x-ray beamline at Frascati Labs

NASA Astrophysics Data System (ADS)

Cinque, Gianfelice; Burattini, Emilio; Grilli, Antonio; Dabagov, Sultan

2005-08-01

DAΦNE-Light is the Synchrotron Radiation laboratory at the Laboratori Nazionali di Frascati (LNF)1. Three beamlines were commissioned since spring 2003 to exploit parasitically the intense photon emission from DAΦNE, the 0.5 1 GeV storage ring routinely circulating over 1 A of electrons. The soft X-ray beamline utilizes a wiggler source and, by a double-crystal fixed-exit monochromator, it is operational in the distinguishing energy window 1.5 - 4 keV range to be extended from the "water window" toward 6 keV. At present, the research activity is focused on X-ray Absorption Spectroscopy (XAS): precisely, X-ray Absorption Near Edge Spectroscopy (XANES) on the inner electronic levels of light elements and transition metals from Al to Ge and both d- and f-shells of higher Z atoms. Preliminary tests of X-ray imaging have been performed in view of applying different focusing optics, namely policapillary systems in trasmission and/or bent mica diffractor in back-reflection, for X-ray microscopy and spectromicroscopy experiments. The use of polycapillary systems (lenses, halflenses, capillaries) for studying features of radiation transportation by such structures (X-ray channelling, focusing, bending, etc.) has been planned.

X-ray system simulation software tools for radiology and radiography education.

PubMed

Kengyelics, Stephen M; Treadgold, Laura A; Davies, Andrew G

2018-02-01

To develop x-ray simulation software tools to support delivery of radiological science education for a range of learning environments and audiences including individual study, lectures, and tutorials. Two software tools were developed; one simulated x-ray production for a simple two dimensional radiographic system geometry comprising an x-ray source, beam filter, test object and detector. The other simulated the acquisition and display of two dimensional radiographic images of complex three dimensional objects using a ray casting algorithm through three dimensional mesh objects. Both tools were intended to be simple to use, produce results accurate enough to be useful for educational purposes, and have an acceptable simulation time on modest computer hardware. The radiographic factors and acquisition geometry could be altered in both tools via their graphical user interfaces. A comparison of radiographic contrast measurements of the simulators to a real system was performed. The contrast output of the simulators had excellent agreement with measured results. The software simulators were deployed to 120 computers on campus. The software tools developed are easy-to-use, clearly demonstrate important x-ray physics and imaging principles, are accessible within a standard University setting and could be used to enhance the teaching of x-ray physics to undergraduate students. Current approaches to teaching x-ray physics in radiological science lack immediacy when linking theory with practice. This method of delivery allows students to engage with the subject in an experiential learning environment. Copyright © 2017. Published by Elsevier Ltd.

Measurement and simulation for a complementary imaging with the neutron and X-ray beams

NASA Astrophysics Data System (ADS)

Hara, Kaoru Y.; Sato, Hirotaka; Kamiyama, Takashi; Shinohara, Takenao

2017-09-01

By using a composite source system, we measured radiographs of the thermal neutron and keV X-ray in the 45-MeV electron linear accelerator facility at Hokkaido University. The source system provides the alternative beam of neutron and X-ray by switching the production target onto the electron beam axis. In the measurement to demonstrate a complementary imaging, the detector based on a vacuum-tube type neutron color image intensifier was applied to the both beams for dual-purpose. On the other hand, for reducing background in a neutron transmission spectrum, test measurements using a gadolinium-type neutron grid were performed with a cold neutron source at Hokkaido University. In addition, the simulations of the neutron and X-ray transmissions for various substances were performed using the PHITS code. A data analysis procedure for estimating the substance of sample was investigated through the simulations.

A rotational and axial motion system load frame insert for in situ high energy x-ray studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shade, Paul A., E-mail: paul.shade.1@us.af.mil; Schuren, Jay C.; Turner, Todd J.

2015-09-15

High energy x-ray characterization methods hold great potential for gaining insight into the behavior of materials and providing comparison datasets for the validation and development of mesoscale modeling tools. A suite of techniques have been developed by the x-ray community for characterizing the 3D structure and micromechanical state of polycrystalline materials; however, combining these techniques with in situ mechanical testing under well characterized and controlled boundary conditions has been challenging due to experimental design requirements, which demand new high-precision hardware as well as access to high-energy x-ray beamlines. We describe the design and performance of a load frame insert withmore » a rotational and axial motion system that has been developed to meet these requirements. An example dataset from a deforming titanium alloy demonstrates the new capability.« less

Focal Plane Detectors for the Advanced Gamma-Ray Imaging System (AGIS)

NASA Astrophysics Data System (ADS)

Wagner, R. G.; Byrum, K.; Drake, G.; Funk, S.; Otte, N.; Smith, A.; Tajima, H.; Williams, D.

2009-05-01

The Advanced Gamma-Ray Imaging System (AGIS) is a concept for the next generation observatory in ground-based very high energy gamma-ray astronomy. It is being designed to achieve a significant improvement in sensitivity compared to current Imaging Air Cherenkov Telescope (IACT) Arrays. One of the main requirements in order that AGIS fulfills this goal will be to achieve higher angular resolution than current IACTs. Simulations show that a substantial improvement in angular resolution may be achieved if the pixel size is reduced to 0.05 deg, i.e. two to three times smaller than for current IACT cameras. Here we present results from testing of alternatives being considered for AGIS, including both silicon photomultipliers (SiPMs) and multi-anode photomultipliers (MAPMTs).

Low energy X-ray spectra measured with a mercuric iodide energy dispersive spectrometer in a scanning electron microscope

NASA Technical Reports Server (NTRS)

Iwanczyk, J. S.; Dabrowski, A. J.; Huth, G. C.; Bradley, J. G.; Conley, J. M.

1986-01-01

A mercuric iodide energy dispersive X-ray spectrometer, with Peltier cooling provided for the detector and input field effect transistor, has been developed and tested in a scanning electron microscope. X-ray spectra were obtained with the 15 keV electron beam. An energy resolution of 225 eV (FWHM) for Mn-K(alpha) at 5.9 keV and 195 eV (FWHM) for the Mg-K line at 1.25 keV has been measured. Overall system noise level was 175 eV (FWHM). The detector system characterization with a carbon target demonstrated good energy sensitivity at low energies and lack of significant spectral artifacts at higher energies.

History of Chandra X-Ray Observatory

NASA Image and Video Library

1997-05-01

This photograph shows the Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), High Resolution Mirror Assembly (HRMA) being removed from the test structure in the X-Ray Calibration Facility (XRCF) at the Marshall Space Flight Center (MSFC). The AXAF was renamed CXO in 1999. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It observes x-rays from high-energy regions of the universe, such as hot gas in the remnants of exploded stars. The HRMA, the heart of the telescope system, is contained in the cylindrical "telescope" portion of the observatory. Since high-energy x-rays would penetrate a normal mirror, special cylindrical mirrors were created. The two sets of four nested mirrors resemble tubes within tubes. Incoming x-rays graze off the highly polished mirror surface and are furneled to the instrument section for detection and study. MSFC's XRCF is the world's largest, most advanced laboratory for simulating x-ray emissions from distant celestial objects. It produces a space-like environment in which components related to x-ray telescope imaging are tested and the quality of their performances in space is predicted. TRW, Inc. was the prime contractor for the development of the CXO and NASA's MSFC was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The CXO was launched July 22, 1999 aboard the Space Shuttle Columbia (STS-93).

History of Chandra X-Ray Observatory

NASA Image and Video Library

1997-05-01

This photograph shows the Chandra X-ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), High Resolution Mirror Assembly (HRMA) being removed from the test structure in the X-Ray Calibration Facility (XRCF) at the Marshall Space Flight Center (MSFC). The AXAF was renamed CXO in 1999. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It observes x-rays from high-energy regions of the universe, such as hot gas in the remnants of exploded stars. The HRMA, the heart of the telescope system, is contained in the cylindrical "telescope" portion of the observatory. Since high-energy x-rays would penetrate a normal mirror, special cylindrical mirrors were created. The two sets of four nested mirrors resemble tubes within tubes. Incoming x-rays graze off the highly polished mirror surface and are furneled to the instrument section for detection and study. MSFC's XRCF is the world's largest, most advanced laboratory for simulating x-ray emissions from distant celestial objects. It produces a space-like environment in which components related to x-ray telescope imaging are tested and the quality of their performances in space is predicted. TRW, Inc. was the prime contractor for the development of the CXO and NASA's MSFC was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The CXO was launched July 22, 1999 aboard the Space Shuttle Columbia (STS-93).

500-MHz x-ray counting with a Si-APD and a fast-pulse processing system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kishimoto, Shunji; Taniguchi, Takashi; Tanaka, Manobu

2010-06-23

We introduce a counting system of up to 500 MHz for synchrotron x-ray high-rate measurements. A silicon avalanche photodiode detector was used in the counting system. The fast-pulse circuit of the amplifier was designed with hybrid ICs to prepare an ASIC system for a large-scale pixel array detector in near future. The fast amplifier consists of two cascading emitter-followers using 10-GHz band transistors. A count-rate of 3.25x10{sup 8} s{sup -1} was then achieved using the system for 8-keV x-rays. However, a baseline shift by adopting AC-coupling in the amplifier disturbed us to observe the maximum count of 4.49x10{sup 8} s{supmore » -1}, determined by electron-bunch filling into a ring accelerator. We also report that an amplifier with a baseline restorer was tested in order to keep the baseline level to be 0 V even at high input rates.« less

Practical application of HgI2 detectors to a space-flight scanning electron microscope

NASA Technical Reports Server (NTRS)

Bradley, J. G.; Conley, J. M.; Albee, A. L.; Iwanczyk, J. S.; Dabrowski, A. J.

1989-01-01

Mercuric iodide X-ray detectors have been undergoing tests in a prototype scanning electron microscope system being developed for unmanned space flight. The detector program addresses the issues of geometric configuration in the SEM, compact packaging that includes separate thermoelectric coolers for the detector and FET, X-ray transparent hermetic encapsulation and electrical contacts, and a clean vacuum environment.

Space simulation techniques and facilities for SAX STM test campaign

NASA Technical Reports Server (NTRS)

Giordano, Pietro; Raimondo, Giacomo; Messidoro, Piero

1994-01-01

SAX is a satellite for X-Ray astronomy. It is a major element of the overall basic Science Program of the Italian Space Agency (ASI) and is being developed with the contribution of the Netherlands Agency for Aerospace Programs (NIVR). The scientific objectives of SAX are to carry out systematic and comprehensive observations of celestial X-Ray sources over the 0.1 - 300 KeV energy range with special emphasis on spectral and timing measurements. The satellite will also monitor the X-Ray sky to investigate long-term source variability and to permit localization and study of X-Ray transients. Alenia Spazio is developing the satellite that is intended for launch in the second half of 1995 in a low, near-equatorial Earth orbit. At system level a Structural Thermal Model (STM) has been conceived to verify the environmental requirements by validating the mechanical and thermal analytical models and qualifying satellite structure and thermal control. In particular, the following tests have been carried out in Alenia Spazio, CEA/CESTA and ESTEC facilities: Modal Survey, Centrifuge, Acoustic, Sinusoidal/Random Vibration and Thermal Balance. The paper, after a short introduction of the SAX satellite, summarizes the environmental qualification program performed on the SAX STM. It presents test objectives, methodologies and relevant test configurations. Peculiar aspects of the test campaign are highlighted. Problems encountered and solutions adopted in performing the tests are described as well. Furthermore, test results are presented and assessed.

Large field of view, fast and low dose multimodal phase-contrast imaging at high x-ray energy.

PubMed

Astolfo, Alberto; Endrizzi, Marco; Vittoria, Fabio A; Diemoz, Paul C; Price, Benjamin; Haig, Ian; Olivo, Alessandro

2017-05-19

X-ray phase contrast imaging (XPCI) is an innovative imaging technique which extends the contrast capabilities of 'conventional' absorption based x-ray systems. However, so far all XPCI implementations have suffered from one or more of the following limitations: low x-ray energies, small field of view (FOV) and long acquisition times. Those limitations relegated XPCI to a 'research-only' technique with an uncertain future in terms of large scale, high impact applications. We recently succeeded in designing, realizing and testing an XPCI system, which achieves significant steps toward simultaneously overcoming these limitations. Our system combines, for the first time, large FOV, high energy and fast scanning. Importantly, it is capable of providing high image quality at low x-ray doses, compatible with or even below those currently used in medical imaging. This extends the use of XPCI to areas which were unpractical or even inaccessible to previous XPCI solutions. We expect this will enable a long overdue translation into application fields such as security screening, industrial inspections and large FOV medical radiography - all with the inherent advantages of the XPCI multimodality.

AXAF VETA-I mirror ring focus measurements

NASA Technical Reports Server (NTRS)

Tananbaum, H. D.; Zhao, P.

1994-01-01

The AXAF VETA-I mirror ring focus measurements were made with an HRI (microchannel plate) X-ray detector. The ring focus is a sharply focused ring formed by X-rays before they reach the VEAT-I focal plane. It is caused by spherical aberrations due to the finite source distance and the despace in the VETA-I test. The ring focus test reveals some aspects fo the test system distortions and the mirror surface figure which are difficult or impossible to detect at the focal plane. The test results show periodic modulations of the ring radius and width which could be caused by gravity, thermal, and/or epoxy shrinkage distortions. The strongest component of the modulation had a 12-fold symmetry, because these distortions were exerted on the mirror through 12 flexures of the VETA-I mount. Ring focus models were developed to simulate the ring image. The models were compared with the data to understand the test system distortions and the mirror glass imperfection. Further studies will be done to complete this work. The ring focus measurement is a very powerful test. We expect that a similar test for the finally assembled mirror of AXAD-I will be highly valuable.

Fentanyl Iontophoretic Transdermal System (IONSYS(®)) can be Safely used in the Hospital Environment with X-Rays, Computerized Tomography and Radiofrequency Identification Devices.

PubMed

Lemke, John; Sardariani, Edmond; Phipps, Joseph Bradley; Patel, Niki; Itri, Loretta M; Caravelli, James; Viscusi, Eugene R

2016-09-01

Fentanyl iontophoretic transdermal system (fentanyl ITS, IONSYS(®)) is a patient-controlled analgesia system used for the management of acute postoperative pain, designed to be utilized in a hospital setting. The objective of the two studies was to determine if fentanyl ITS could be safely used with X-rays, computerized tomography (CT) scans and radiofrequency identification (RFID) devices. The ITS system has two components: controller and drug unit; the studies utilized ITS systems without fentanyl, referred to as the ITS Placebo system. The first study evaluated the effect of X-radiation on the operation of an ITS Placebo system. Five ITS Placebo systems were exposed to X-rays (20 and 200 mSv total radiation dose-the 200 mSv radiation dose represents a tenfold higher exposure than in clinical practice) while operating in the Ready Mode and five were exposed while operating in the Dose Mode. The second study evaluated the effect of RFID (worst-case scenario of direct contact with an RFID transmitter) on the operation of an ITS Placebo system. During these tests, observations of the user interface and measurements of output voltage confirmed proper function throughout all operational modes (Ready Mode, Dose Mode, End-of-Use Mode, and End-of-Life Mode). The ITS Placebo system met all specifications and no functional anomalies were observed during and following X-ray exposure at two radiation dose levels or exposure at six different combinations of RFID frequencies and field strengths. The performance of the ITS system was unaffected by X-ray exposure levels well beyond those associated with diagnostic X-rays and CT scans, and by exposure to radiofrequency field strengths typically generated by RFID devices. These results provide added confidence to clinicians that the fentanyl ITS system does not need to be removed during diagnostic X-rays and CT scans and can also be utilized in close proximity to RFID devices. The studies and writing of this manuscript were supported financially by The Medicines Company.

Tissue Equivalent Phantom Design for Characterization of a Coherent Scatter X-ray Imaging System

NASA Astrophysics Data System (ADS)

Albanese, Kathryn Elizabeth

Scatter in medical imaging is typically cast off as image-related noise that detracts from meaningful diagnosis. It is therefore typically rejected or removed from medical images. However, it has been found that every material, including cancerous tissue, has a unique X-ray coherent scatter signature that can be used to identify the material or tissue. Such scatter-based tissue-identification provides the advantage of locating and identifying particular materials over conventional anatomical imaging through X-ray radiography. A coded aperture X-ray coherent scatter spectral imaging system has been developed in our group to classify different tissue types based on their unique scatter signatures. Previous experiments using our prototype have demonstrated that the depth-resolved coherent scatter spectral imaging system (CACSSI) can discriminate healthy and cancerous tissue present in the path of a non-destructive x-ray beam. A key to the successful optimization of CACSSI as a clinical imaging method is to obtain anatomically accurate phantoms of the human body. This thesis describes the development and fabrication of 3D printed anatomical scatter phantoms of the breast and lung. The purpose of this work is to accurately model different breast geometries using a tissue equivalent phantom, and to classify these tissues in a coherent x-ray scatter imaging system. Tissue-equivalent anatomical phantoms were designed to assess the capability of the CACSSI system to classify different types of breast tissue (adipose, fibroglandular, malignant). These phantoms were 3D printed based on DICOM data obtained from CT scans of prone breasts. The phantoms were tested through comparison of measured scatter signatures with those of adipose and fibroglandular tissue from literature. Tumors in the phantom were modeled using a variety of biological tissue including actual surgically excised benign and malignant tissue specimens. Lung based phantoms have also been printed for future testing. Our imaging system has been able to define the location and composition of the various materials in the phantom. These phantoms were used to characterize the CACSSI system in terms of beam width and imaging technique. The result of this work showed accurate modeling and characterization of the phantoms through comparison of the tissue-equivalent form factors to those from literature. The physical construction of the phantoms, based on actual patient anatomy, was validated using mammography and computed tomography to visually compare the clinical images to those of actual patient anatomy.

Instruments for the nondestructive testing of materials and products: Handbook. Volumes 1 & 2 (2nd revised and enlarged edition)

NASA Astrophysics Data System (ADS)

Kliuev, V. V.

Data on the general design and principles of operation of various instruments and systems for the nondestructive testing of materials and products of various kinds are presented, and test procedures are described. Methods discussed include optical, thermal, capillary, RF, and X-ray testing techniques. The discussion also covers magnetic, electromagnetic, eddy-current, acoustic, and combined nondestructive testing methods.

Real-Time X-ray Radiography Diagnostics of Components in Solid Rocket Motors

NASA Technical Reports Server (NTRS)

Cortopassi, A. C.; Martin, H. T.; Boyer, E.; Kuo, K. K.

2012-01-01

Solid rocket motors (SRMs) typically use nozzle materials which are required to maintain their shape as well as insulate the underlying support structure during the motor operation. In addition, SRMs need internal insulation materials to protect the motor case from the harsh environment resulting from the combustion of solid propellant. In the nozzle, typical materials consist of high density graphite, carbon-carbon composites and carbon phenolic composites. Internal insulation of the motor cases is typically a composite material with carbon, asbestos, Kevlar, or silica fibers in an ablative matrix such as EPDM or NBR. For both nozzle and internal insulation materials, the charring process occurs when the hot combustion products heat the material intensely. The pyrolysis of the matrix material takes away a portion of the thermal energy near the wall surface and leaves behind a char layer. The fiber reinforcement retains the porous char layer which provides continued thermal protection from the hot combustion products. It is of great interest to characterize both the total erosion rates of the material and the char layer thickness. By better understanding of the erosion process for a particular ablative material in a specific flow environment, the required insulation material thickness can be properly selected. The recession rates of internal insulation and nozzle materials of SRMs are typically determined by testing in some sort of simulated environment; either arc-jet testing, flame torch testing, or subscale SRMs of different size. Material recession rates are deduced by comparison of pre- and post-test measurements and then averaging over the duration of the test. However, these averaging techniques cannot be used to determine the instantaneous recession rates of the material. Knowledge of the variation in recession rates in response to the instantaneous flow conditions during the motor operation is of great importance. For example, in many SRM configurations the recession of the solid propellant grain can drastically alter the flow-field and effect the recession of internal insulation and nozzle materials. Simultaneous measurement of the overall erosion rate, the development of the char layer, and the recession of the char-virgin interface during the motor operation can be rather difficult. While invasive techniques have been used with limited success, they have serious drawbacks. Break wires or make wire sensors can be installed into a sufficient number of locations in the charring material from which a time history of the charring surface can be deduced. These sensors fundamentally alter the local structure of the material in which they are imbedded. Also, the location of these sensors within the material is not known precisely without the use of an X-ray. To determine instantaneous recession rates, real-time X-ray radiography (X-ray RTR) has been utilized in several SRM experiments at PSU. The X-ray RTR system discussed in this paper consists of an X-ray source, X-ray image intensifier, and CCD camera connected to a capture computer. The system has been used to examine the ablation process of internal insulation as well as nozzle material erosion in a subscale SRM. The X-ray source is rated to 320 kV at 10 mA and has both a large (5.5 mm) and small (3.0 mm) focal spot. The lead-lined cesium iodide X-ray image intensifier produces an image which is captured by a CCD camera with a 1,000 x 1,000 pixel resolution. To produce accurate imagery of the object of interest, the alignment of the X-ray source to the X-ray image intensifier is crucial. The image sequences captured during the operation of an SRM are then processed to enhance the quality of the images. This procedure allows for computer software to extract data on the total erosion rate and the char layer thickness. Figure 1 Error! Reference source not found.shows a sequence of images captured during the operation the subscale SRM with the X-ray RTR system. The X-rayTR system, alignment procedure, uncertainty determination, and image analysis process will be discussed in detail in the full manuscript.

Phase contrast imaging simulation and measurements using polychromatic sources with small source-object distances

DOE Office of Scientific and Technical Information (OSTI.GOV)

Golosio, Bruno; Carpinelli, Massimo; Masala, Giovanni Luca

Phase contrast imaging is a technique widely used in synchrotron facilities for nondestructive analysis. Such technique can also be implemented through microfocus x-ray tube systems. Recently, a relatively new type of compact, quasimonochromatic x-ray sources based on Compton backscattering has been proposed for phase contrast imaging applications. In order to plan a phase contrast imaging system setup, to evaluate the system performance and to choose the experimental parameters that optimize the image quality, it is important to have reliable software for phase contrast imaging simulation. Several software tools have been developed and tested against experimental measurements at synchrotron facilities devotedmore » to phase contrast imaging. However, many approximations that are valid in such conditions (e.g., large source-object distance, small transverse size of the object, plane wave approximation, monochromatic beam, and Gaussian-shaped source focal spot) are not generally suitable for x-ray tubes and other compact systems. In this work we describe a general method for the simulation of phase contrast imaging using polychromatic sources based on a spherical wave description of the beam and on a double-Gaussian model of the source focal spot, we discuss the validity of some possible approximations, and we test the simulations against experimental measurements using a microfocus x-ray tube on three types of polymers (nylon, poly-ethylene-terephthalate, and poly-methyl-methacrylate) at varying source-object distance. It will be shown that, as long as all experimental conditions are described accurately in the simulations, the described method yields results that are in good agreement with experimental measurements.« less

X-ray spectroscopy of the SSME plume

NASA Technical Reports Server (NTRS)

Olive, Dan F.

1988-01-01

In order to examine the potential of using SSME exhaust plume radiation in the soft X-ray spectrum as an early warning system of imminent engine failure, a low cost, low risk experiment was devised. An approach was established, equipment was leased, the system was installed and checked out, and data were successfully acquired demonstrating the proof-of-concept. One spectrum measurement of the SSME plume was acquired during a 300 second burn on the A-1 Test Stand. This spectrum showed a prominent, line emission feature at about 34.5 KeV, a result which was not expected, nor can it be explained at this time. If X-ray spectra are to be useful as a means of monitoring nominal engine operation, it will be necessary to explore this region of the EM spectrum in greater detail. The presence of structure in the spectrum indicates that this technology may prove to be useful as an engine health monitoring system.

Complete blood counts, liver function tests, and chest x-rays as routine screening in early-stage breast cancer: value added or just cost?

PubMed

Louie, Raphael J; Tonneson, Jennifer E; Gowarty, Minda; Goodney, Philip P; Barth, Richard J; Rosenkranz, Kari M

2015-11-01

Current National Comprehensive Cancer Network guidelines for breast cancer staging include pre-treatment complete blood count (CBC) and liver function tests (LFT) to screen for occult metastatic disease. To date, the relevance of these tests in detecting metastatic disease in asymptomatic women with early-stage breast cancer (Stage I/II) has not been demonstrated. Although chest x-rays are no longer recommended in the NCCN guidelines, many centers continue to include this imaging as part of their screening process. We aim to determine the clinical and financial impact of these labs and x-rays in the evaluation of early-stage breast cancer patients. A single institution IRB-approved retrospective chart review was conducted of patients with biopsy-proven invasive breast cancer treated from January 1, 2005–December 31, 2009. We collected patient demographics, clinical and pathologic staging, chest x-ray, CBC, and LFT results at the time of referral. Patients were stratified according to radiographic stage at the time of diagnosis. We obtained Medicare reimbursement fees for cost analysis. From 2005 to 2009, 1609 patients with biopsy-proven invasive breast cancer were treated at our institution. Of the 1082 patients with radiographic stage I/II disease, 27.3 % of patients had abnormal CBCs. No additional testing was performed to evaluate these abnormalities. In the early-stage population, 24.7 % of patients had elevated LFTs, resulting in 84 additional imaging studies. No metastatic disease was detected. The cost of CBC, LFTs and chest x-rays was $110.20 per patient, totaling $106,410.99. Additional tests prompted by abnormal results cost $58,143.30 over the five-year period. We found that pre-treatment CBCs, LFTs, and chest x-rays did not improve detection of occult metastatic disease but resulted in additional financial costs. Avoiding routine ordering of these tests would save the US healthcare system $25.7 million annually.

Improved Cryogenic Optical Test Capability at Marshall Space Flight Center's X-ray Cryogenic Test Facility

NASA Technical Reports Server (NTRS)

Kegley, Jeffrey; Haight, Harlan; Hogue, William; Carpenter, Jay; Siler, Richard; Wright, Ernie; Eng, Ron; Baker, Mark; McCracken, Jeff

2005-01-01

Marshall Space Flight Center's X-ray & Cryogenic Test Facility (XRCF) has been performing optical wavefront testing and thermal structural deformation testing at subliquid nitrogen cryogenic temperatures since 1999. Recent modifications have been made to the facility in support of the James Webb Space Telescope (JWST) program. The test article envelope and the chamber's refrigeration capacity have both been increased. A new larger helium-cooled enclosure has been added to the existing enclosure increasing both the cross-sectional area and the length. This new enclosure is capable of supporting six JWST Primary Mirror Segment Assemblies. A second helium refrigeration system has been installed essentially doubling the cooling capacity available at the facility. Modifications have also been made to the optical instrumentation area. Improved access is now available for both the installation and operation of optical instrumentation outside the vacuum chamber. Chamber configuration, specifications, and performance data will be presented.

X-ray free-electron laser studies of dense plasmas

NASA Astrophysics Data System (ADS)

Vinko, Sam M.

2015-10-01

> The high peak brightness of X-ray free-electron lasers (FELs), coupled with X-ray optics enabling the focusing of pulses down to sub-micron spot sizes, provides an attractive route to generating high energy-density systems on femtosecond time scales, via the isochoric heating of solid samples. Once created, the fundamental properties of these plasmas can be studied with unprecedented accuracy and control, providing essential experimental data needed to test and benchmark commonly used theoretical models and assumptions in the study of matter in extreme conditions, as well as to develop new predictive capabilities. Current advances in isochoric heating and spectroscopic plasma studies on X-ray FELs are reviewed and future research directions and opportunities discussed.

Addition of tracers into the polypropylene in view of automatic sorting of plastic wastes using X-ray fluorescence spectrometry.

PubMed

Bezati, F; Froelich, D; Massardier, V; Maris, E

2010-04-01

This study focused on the detection of rare earth oxides, used as tracers for the identification of polymer materials, using XRF (X-ray fluorescence) spectrometry. The tests were carried out in a test system device which allows the collection of static measurements of the samples' spectrum through the use of energy dispersive X-ray fluorescence technology. A sorting process based on tracers added into the polymer matrix is proposed in order to increase sorting selectivity of polypropylene during end-of-life recycling. Tracers consist of systems formed by one or by several substances dispersed into a material, to add a selective property to it, with the aim of improving the efficiency of sorting and high speed identification. Several samples containing rare earth oxides (Y(2)O(3), CeO(2), Nd(2)O(3), Gd(2)O(3), Dy(2)O(3), Er(2)O(3) and Yb(2)O(3)) in different concentrations were prepared in order to analyse some of the parameters which can influence the detection, such as the concentration of tracers, the acquisition time and the possible overlapping among the tracers. This work shows that by using the XRF test system device, it was possible to detect 5 of the 7 tracers tested for 1min exposure time and at a concentration level of 1000ppm. These two parameters will play an important role in the development of an industrial device, which indicates the necessity of further works that needs to be conducted in order to reduce them. Copyright 2009 Elsevier Ltd. All rights reserved.

Status of the eROSITA Telescope testing and calibrating the x-ray mirror assemblies

NASA Astrophysics Data System (ADS)

Burwitz, Vadim; Predehl, Peter; Bräuninger, Heinrich; Burkert, Wolfgang; Dennerl, Konrad; Eder, Josef; Friedrich, Peter; Fürmetz, Maria; Grisoni, Gabriele; Hartner, Gisela; Marioni, Fabio; Menz, Benedikt; Pfeffermann, Elmar; Valsecchi, Giuseppe

2013-09-01

The eROSITA X-ray observatory that will be launched on board the Russian Spectrum-RG mission comprises seven X-ray telescopes, each with its own mirror assembly (mirror module + X-ray baffle), electron deflector, filter wheel, and CCD camera with its control electronics. The completed flight mirror modules are undergoing many thorough X-ray tests at the PANTHER X-ray test facility after delivery, after being mated with the X-ray baffle, and again after both the vibration and thermal-vacuum tests. A description of the work done with mirror modules/assemblies and the test results obtained will be reported here. We report also on the environmental tests that have been performed on the eROSITA telescope qualification model.

A Compendium of Solar Dish/Stirling Technology

DTIC Science & Technology

1994-01-01

systems and Plataforma Solar in Almeria, Spain, with the goal being plans to produce fourteen 7.5-kWe systems for testing to test the system’s long-term...the sun is not a point source, its rays 21 Chapter 3 (a) (b) - N Mounting Ring and CollaraI/ / I/\\ I / Virtual Exit I / Target S• Entrance I 0 L...tptical \\ I Real Exit / Virtual Target \\ Aperture\\ / Cooling \\ / I Coils N - Focal - - - - " Plane 4. Figure 3-2. A secondary concentrator with side view (a

Multi-species beam hardening calibration device for x-ray microtomography

NASA Astrophysics Data System (ADS)

Evershed, Anthony N. Z.; Mills, David; Davis, Graham

2012-10-01

Impact-source X-ray microtomography (XMT) is a widely-used benchtop alternative to synchrotron radiation microtomography. Since X-rays from a tube are polychromatic, however, greyscale `beam hardening' artefacts are produced by the preferential absorption of low-energy photons in the beam path. A multi-material `carousel' test piece was developed to offer a wider range of X-ray attenuations from well-characterised filters than single-material step wedges can produce practically, and optimization software was developed to produce a beam hardening correction by use of the Nelder-Mead optimization method, tuned for specimens composed of other materials (such as hydroxyapatite [HA] or barium for dental applications.) The carousel test piece produced calibration polynomials reliably and with a significantly smaller discrepancy between the calculated and measured attenuations than the calibration step wedge previously in use. An immersion tank was constructed and used to simplify multi-material samples in order to negate the beam hardening effect of low atomic number materials within the specimen when measuring mineral concentration of higher-Z regions. When scanned in water at an acceleration voltage of 90 kV a Scanco AG hydroxyapatite / poly(methyl methacrylate) calibration phantom closely approximates a single-material system, producing accurate hydroxyapatite concentration measurements. This system can then be corrected for beam hardening for the material of interest.

Interactive high-resolution isosurface ray casting on multicore processors.

PubMed

Wang, Qin; JaJa, Joseph

2008-01-01

We present a new method for the interactive rendering of isosurfaces using ray casting on multi-core processors. This method consists of a combination of an object-order traversal that coarsely identifies possible candidate 3D data blocks for each small set of contiguous pixels, and an isosurface ray casting strategy tailored for the resulting limited-size lists of candidate 3D data blocks. While static screen partitioning is widely used in the literature, our scheme performs dynamic allocation of groups of ray casting tasks to ensure almost equal loads among the different threads running on multi-cores while maintaining spatial locality. We also make careful use of memory management environment commonly present in multi-core processors. We test our system on a two-processor Clovertown platform, each consisting of a Quad-Core 1.86-GHz Intel Xeon Processor, for a number of widely different benchmarks. The detailed experimental results show that our system is efficient and scalable, and achieves high cache performance and excellent load balancing, resulting in an overall performance that is superior to any of the previous algorithms. In fact, we achieve an interactive isosurface rendering on a 1024(2) screen for all the datasets tested up to the maximum size of the main memory of our platform.

Space Science

NASA Image and Video Library

2002-02-01

This photograph depicts the Solar X-Ray Imager (SXI) being installed in the X-Ray Calibration Facility (XRCF) vacuum chamber for testing at the Marshall Space Flight Center (MSFC). The XRCF vacuum chamber simulates a space environment with low temperature and pressure. The x-ray images from SXI on the Geostationary Operational Environmental Satellite-12 (GOES-12) will be used by the National Oceanic and Atmospheric Administration (NOAA) and U.S. Air Force to forecast the intensity and speed of solar disturbances that could destroy satellite electronics or disrupt long-distance radio communications. The SXI will observe solar flares, coronal mass ejections, coronal holes, and active regions in the x-ray region of the electromagnetic spectrum. These features are the dominant sources of disturbances in space weather. The imager instrument consists of a telescope assembly with a 6.3-inch (16-centimeter) diameter grazing incidence mirror and a detector system. The imager was developed, tested, and calibrated by MSFC, in conjunction with the NASA Goddard Space Flight Center and U.S. Air Force.

Microanalysis of extended-test xenon hollow cathodes

NASA Technical Reports Server (NTRS)

Verhey, Timothy R.; Patterson, Michael J.

1991-01-01

Four hollow cathode electron sources were analyzed via boroscopy, scanning electron microscopy, energy dispersive x ray analysis, and x ray diffraction analysis. These techniques were used to develop a preliminary understanding of the chemistry of the devices that arise from contamination due to inadequate feed-system integrity and improper insert activation. Two hollow cathodes were operated in an ion thruster simulator at an emission current of 23.0 A for approximately 500 hrs. The two tests differed in propellant-feed systems, discharge power supplies, and activation procedures. Tungsten deposition and barium tungstate formation on the internal cathode surfaces occurred during the first test, which were believed to result from oxygen contamination of the propellant feed-system. Consequently, the test facility was upgraded to reduce contamination, and the test was repeated. The second hollow cathode was found to have experienced significantly less tungsten deposition. A second pair of cathodes examined were the discharge and the neutralizer hollow cathodes used in a life-test of a 30-cm ring-cusp ion thruster at a 5.5 kW power level. The cathodes' test history was documented and the post-test microanalyses are described. The most significant change resulting from the life-test was substantial tungsten deposition on the internal cathode surfaces, as well as removal of material from the insert surface. In addition, barium tungstate and molybdate were found on insert surfaces. As a result of the cathode examinations, procedures and approaches were proposed for improved discharge ignition and cathode longevity.

AXAF Alignment Test System Autocollimating Flat Error Correction

NASA Technical Reports Server (NTRS)

Lewis, Timothy S.

1995-01-01

The alignment test system for the advanced x ray astrophysics facility (AXAF) high-resolution mirror assembly (HRMA) determines the misalignment of the HRMA by measuring the displacement of a beam of light reflected by the HRMA mirrors and an autocollimating flat (ACF). This report shows how to calibrate the system to compensate for errors introduced by the ACF, using measurements taken with the ACF in different positions. It also shows what information can be obtained from alignment test data regarding errors in the shapes of the HRMA mirrors. Simulated results based on measured ACF surface data are presented.

The Topo-trigger: a new concept of stereo trigger system for imaging atmospheric Cherenkov telescopes

NASA Astrophysics Data System (ADS)

López-Coto, R.; Mazin, D.; Paoletti, R.; Blanch Bigas, O.; Cortina, J.

2016-04-01

Imaging atmospheric Cherenkov telescopes (IACTs) such as the Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes endeavor to reach the lowest possible energy threshold. In doing so the trigger system is a key element. Reducing the trigger threshold is hampered by the rapid increase of accidental triggers generated by ambient light (the so-called Night Sky Background NSB). In this paper we present a topological trigger, dubbed Topo-trigger, which rejects events on the basis of their relative orientation in the telescope cameras. We have simulated and tested the trigger selection algorithm in the MAGIC telescopes. The algorithm was tested using MonteCarlo simulations and shows a rejection of 85% of the accidental stereo triggers while preserving 99% of the gamma rays. A full implementation of this trigger system would achieve an increase in collection area between 10 and 20% at the energy threshold. The analysis energy threshold of the instrument is expected to decrease by ~ 8%. The selection algorithm was tested on real MAGIC data taken with the current trigger configuration and no γ-like events were found to be lost.

Low-Energy Microfocus X-Ray Source for Enhanced Testing Capability in the Stray Light Facility

NASA Technical Reports Server (NTRS)

Gaskin, Jessica; O'Dell, Stephen; Kolodziejczak, Jeff

2015-01-01

Research toward high-resolution, soft x-ray optics (mirrors and gratings) necessary for the next generation large x-ray observatories requires x-ray testing using a low-energy x-ray source with fine angular size (<1 arcsecond). To accommodate this somewhat demanding requirement, NASA Marshall Space Flight Center (MSFC) has procured a custom, windowless low-energy microfocus (approximately 0.1 mm spot) x-ray source from TruFocus Corporation that mates directly to the Stray Light Facility (SLF). MSFC X-ray Astronomy team members are internationally recognized for their expertise in the development, fabrication, and testing of grazing-incidence optics for x-ray telescopes. One of the key MSFC facilities for testing novel x-ray instrumentation is the SLF. This facility is an approximately 100-m-long beam line equipped with multiple x-ray sources and detectors. This new source adds to the already robust compliment of instrumentation, allowing MSFC to support additional internal and community x-ray testing needs.

MARS: a mouse atlas registration system based on a planar x-ray projector and an optical camera

NASA Astrophysics Data System (ADS)

Wang, Hongkai; Stout, David B.; Taschereau, Richard; Gu, Zheng; Vu, Nam T.; Prout, David L.; Chatziioannou, Arion F.

2012-10-01

This paper introduces a mouse atlas registration system (MARS), composed of a stationary top-view x-ray projector and a side-view optical camera, coupled to a mouse atlas registration algorithm. This system uses the x-ray and optical images to guide a fully automatic co-registration of a mouse atlas with each subject, in order to provide anatomical reference for small animal molecular imaging systems such as positron emission tomography (PET). To facilitate the registration, a statistical atlas that accounts for inter-subject anatomical variations was constructed based on 83 organ-labeled mouse micro-computed tomography (CT) images. The statistical shape model and conditional Gaussian model techniques were used to register the atlas with the x-ray image and optical photo. The accuracy of the atlas registration was evaluated by comparing the registered atlas with the organ-labeled micro-CT images of the test subjects. The results showed excellent registration accuracy of the whole-body region, and good accuracy for the brain, liver, heart, lungs and kidneys. In its implementation, the MARS was integrated with a preclinical PET scanner to deliver combined PET/MARS imaging, and to facilitate atlas-assisted analysis of the preclinical PET images.

MARS: a mouse atlas registration system based on a planar x-ray projector and an optical camera.

PubMed

Wang, Hongkai; Stout, David B; Taschereau, Richard; Gu, Zheng; Vu, Nam T; Prout, David L; Chatziioannou, Arion F

2012-10-07

This paper introduces a mouse atlas registration system (MARS), composed of a stationary top-view x-ray projector and a side-view optical camera, coupled to a mouse atlas registration algorithm. This system uses the x-ray and optical images to guide a fully automatic co-registration of a mouse atlas with each subject, in order to provide anatomical reference for small animal molecular imaging systems such as positron emission tomography (PET). To facilitate the registration, a statistical atlas that accounts for inter-subject anatomical variations was constructed based on 83 organ-labeled mouse micro-computed tomography (CT) images. The statistical shape model and conditional Gaussian model techniques were used to register the atlas with the x-ray image and optical photo. The accuracy of the atlas registration was evaluated by comparing the registered atlas with the organ-labeled micro-CT images of the test subjects. The results showed excellent registration accuracy of the whole-body region, and good accuracy for the brain, liver, heart, lungs and kidneys. In its implementation, the MARS was integrated with a preclinical PET scanner to deliver combined PET/MARS imaging, and to facilitate atlas-assisted analysis of the preclinical PET images.

Development of x-ray imaging technique for liquid screening at airport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sulaiman, Nurhani binti, E-mail: nhani.sulaiman@gmail.com; Srisatit, Somyot, E-mail: somyot.s@chula.ac.th

2016-01-22

X-ray imaging technology is a viable option to recognize flammable liquids for the purposes of aviation security. In this study, an X-ray imaging technology was developed whereby, the image viewing system was built with the use of a digital camera coupled with a gadolinium oxysulfide (GOS) fluorescent screen. The camera was equipped with a software for remote control setting of the camera via a USB cable which allows the images to be captured. The image was analysed to determine the average grey level using a software designed by Microsoft Visual Basic 6.0. The data was obtained for various densities ofmore » liquid thickness of 4.5 cm, 6.0 cm and 7.5 cm respectively for X-ray energies ranging from 70 to 200 kVp. In order to verify the reliability of the constructed calibration data, the system was tested with a few types of unknown liquids. The developed system could be conveniently employed for security screening in order to discriminate between a threat and an innocuous liquid.« less

Eclipsing Pulsar Promises Clues to Crushed Matter

NASA Image and Video Library

2017-12-08

NASA image release August 17, 2010 Astronomers using NASA's Rossi X-ray Timing Explorer (RXTE) have found the first fast X-ray pulsar to be eclipsed by its companion star. Further studies of this unique stellar system will shed light on some of the most compressed matter in the universe and test a key prediction of Einstein's relativity theory. Known as Swift J1749.4-2807 -- J1749 for short -- the system erupted with an X-ray outburst on April 10. During the event, RXTE observed three eclipses, detected X-ray pulses that identified the neutron star as a pulsar, and even recorded pulse variations that indicated the neutron star's orbital motion. To view a video of this pulsar go here: www.flickr.com/photos/gsfc/4901238111 To read more click here Credit: NASA/GSFC NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe. Follow us on Twitter Join us on Facebook

Effects of a descending lithospheric slab on yield estimates of underground nuclear tests. Final technical report, 8 Mar 88-31 Aug 90

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cormier, V.F.; Kim, W.; Mandal, B.

A method for computing seismic wavefields in a high-frequency approximation is proposed based on the integration of the kinematic ray tracing equations and a new set of differential equations for the dynamic properties of the wavefront, which the authors call the vicinity ray tracing (VRT) equations. These equations are directly obtained from the Hamiltonian in ray centered coordinates, using no paraxial approximations. This system is comparable to the standard dynamic ray tracing (DRT) system, but it is specified by fewer equations (four versus eight in 3-D) and only requires the specification of velocity and its first spacial derivative along amore » ray. The VRT equations describe the trajectory of a ray in ray centered coordinates of a reference ray. Quantities obtained from vicinity ray tracing can be used to determine wavefront curvature, geometric spreading, travel time to a receiver near the reference ray, and the KMAH index of the reference ray with greater numerical precision than is possible by differencing kinematically traced rays. Since second spatial derivatives of velocity are not required by the new technique, parameterization of the medium is simplified, and reflection and transmission of beams can be calculated by applying Snell's law to both vicinity and central rays. Conversation relations between VRT and DRT can be used to determine the paraxial vicinity of DRT, in which the errors of the paraxial approximations of DRT remain small. Because no paraxial approximations are made, the superposition of the Gaussian beams define from the vicinity rays should exhibit a much slower breakdown in accuracy as the scale length of the medium given by V/Delta v approaches the beamwidth.« less

Experiment in Assessing Color Separation Techniques for Identifying Small Density Variations in Tires

DOT National Transportation Integrated Search

1972-07-01

An experimental color system was tested as an adjunct to the X-ray fluoroscopy system already in use. Shades of gray were translated into various colors as a means of enhancing small defects normally observed with difficulty, and to provide for more ...

Focal Plane Detectors for the Advanced Gamma-Ray Imaging System (AGIS)

NASA Astrophysics Data System (ADS)

Otte, A. N.; Byrum, K.; Drake, G.; Falcone, A.; Funk, S.; Horan, D.; Mukherjee, R.; Smith, A.; Tajima, H.; Wagner, R. G.; Williams, D. A.

2008-12-01

The Advanced Gamma-Ray Imaging System (AGIS) is a concept for the next generation observatory in ground-based very high energy gamma-ray astronomy. Design goals are ten times better sensitivity, higher angular resolution, and a lower energy threshold than existing Cherenkov telescopes. Simulations show that a substantial improvement in angular resolution may be achieved if the pixel diameter is reduced to the order of 0.05 deg, i.e. two to three times smaller than the pixel diameter of current Cherenkov telescope cameras. At these dimensions, photon detectors with smaller physical dimensions can be attractive alternatives to the classical photomultiplier tube (PMT). Furthermore, the operation of an experiment with the size of AGIS requires photon detectors that are among other things more reliable, more durable, and possibly higher efficiency photon detectors. Alternative photon detectors we are considering for AGIS include both silicon photomultipliers (SiPMs) and multi-anode photomultipliers (MAPMTs). Here we present results from laboratory testing of MAPMTs and SiPMs along with results from the first incorporation of these devices into cameras on test bed Cherenkov telescopes.

High-mass X-ray binary populations. 1: Galactic modeling

NASA Technical Reports Server (NTRS)

Dalton, William W.; Sarazin, Craig L.

1995-01-01

Modern stellar evolutionary tracks are used to calculate the evolution of a very large number of massive binary star systems (M(sub tot) greater than or = 15 solar mass) which cover a wide range of total masses, mass ratios, and starting separations. Each binary is evolved accounting for mass and angular momentum loss through the supernova of the primary to the X-ray binary phase. Using the observed rate of star formation in our Galaxy and the properties of massive binaries, we calculate the expected high-mass X-ray binary (HMXRB) population in the Galaxy. We test various massive binary evolutionary scenarios by comparing the resulting HMXRB predictions with the X-ray observations. A major goal of this study is the determination of the fraction of matter lost from the system during the Roche lobe overflow phase. Curiously, we find that the total numbers of observable HMXRBs are nearly independent of this assumed mass-loss fraction, with any of the values tested here giving acceptable agreement between predicted and observed numbers. However, comparison of the period distribution of our HMXRB models with the observed period distribution does reveal a distinction among the various models. As a result of this comparison, we conclude that approximately 70% of the overflow matter is lost from a massive binary system during mass transfer in the Roche lobe overflow phase. We compare models constructed assuming that all X-ray emission is due to accretion onto the compact object from the donor star's wind with models that incorporate a simplified disk accretion scheme. By comparing the results of these models with observations, we conclude that the formation of disks in HMXRBs must be relatively common. We also calculate the rate of formation of double degenerate binaries, high velocity detached compact objects, and Thorne-Zytkow objects.

Quantification technology study on flaws in steam-filled pipelines based on image processing

NASA Astrophysics Data System (ADS)

Sun, Lina; Yuan, Peixin

2009-07-01

Starting from exploiting the applied detection system of gas transmission pipeline, a set of X-ray image processing methods and pipeline flaw quantificational evaluation methods are proposed. Defective and non-defective strings and rows in gray image were extracted and oscillogram was obtained. We can distinguish defects in contrast with two gray images division. According to the gray value of defects with different thicknesses, the gray level depth curve is founded. Through exponential and polynomial fitting way to obtain the attenuation mathematical model which the beam penetrates pipeline, thus attain flaw deep dimension. This paper tests on the PPR pipe in the production of simulated holes flaw and cracks flaw, 135KV used the X-ray source on the testing. Test results show that X-ray image processing method, which meet the needs of high efficient flaw detection and provide quality safeguard for thick oil recovery, can be used successfully in detecting corrosion of insulated pipe.

HESS J1844-030: A New Gamma-Ray Binary?

NASA Astrophysics Data System (ADS)

McCall, Hannah; Errando, Manel

2018-01-01

Gamma-ray binaries are comprised of a massive, main-sequence star orbiting a neutron star or black hole that generates bright gamma-ray emission. Only six of these systems have been discovered. Here we report on a candidate stellar-binary system associated with the unidentified gamma-ray source HESS J1844-030, whose detection was revealed in the H.E.S.S. galactic plane survey. Analysis of 60 ks of archival Chandra data and over 100 ks of XMM-Newton data reveal a spatially associated X-ray counterpart to this TeV-emitting source (E>1012 eV), CXO J1845-031. The X-ray spectra derived from these exposures yields column density absorption in the range nH = (0.4 - 0.7) x 1022 cm-2, which is below the total galactic value for that part of the sky, indicating that the source is galactic. The flux from CXO J1845-031 increases with a factor of up to 2.5 in a 60 day timescale, providing solid evidence for flux variability at a confidence level exceeding 7 standard deviations. The point-like nature of the source, the flux variability of the nearby X-ray counterpart, and the low column density absorption are all indicative of a binary system. Once confirmed, HESS J1844-030 would represent only the seventh known gamma-ray binary, providing valuable data to advance our understanding of the physics of pulsars and stellar winds and testing high-energy astrophysical processes at timescales not present in other classes of objects.

Observations of breakup processes of liquid jets using real-time X-ray radiography

NASA Technical Reports Server (NTRS)

Char, J. M.; Kuo, K. K.; Hsieh, K. C.

1988-01-01

To unravel the liquid-jet breakup process in the nondilute region, a newly developed system of real-time X-ray radiography, an advanced digital image processor, and a high-speed video camera were used. Based upon recorded X-ray images, the inner structure of a liquid jet during breakup was observed. The jet divergence angle, jet breakup length, and fraction distributions along the axial and transverse directions of the liquid jets were determined in the near-injector region. Both wall- and free-jet tests were conducted to study the effect of wall friction on the jet breakup process.

KSC-08pd0781

NASA Image and Video Library

2008-03-21

CAPE CANAVERAL, Fla. --- In the Astrotech payload processing facility, a General Dynamics technician prepares to test the deployment mechanism on the solar arrays on NASA's Gamma-Ray Large Area Space Telescope, or GLAST. The telescope will launch aboard a Delta II rocket May 16 from Launch Pad 17-B on Cape Canaveral Air Force Station. A powerful space observatory, the GLAST will explore the most extreme environments in the universe, and answer questions about supermassive black hole systems, pulsars and the origin of cosmic rays. It also will study the mystery of powerful explosions known as gamma-ray bursts. Photo credit: NASA/Jim Grossmann

KSC-08pd0784

NASA Image and Video Library

2008-03-21

CAPE CANAVERAL, Fla. --- In the Astrotech payload processing facility, NASA's Gamma-Ray Large Area Space Telescope, or GLAST, completes the test of the deployment mechanism on its solar arrays. The telescope will launch aboard a Delta II rocket May 16 from Launch Pad 17-B on Cape Canaveral Air Force Station. A powerful space observatory, the GLAST will explore the most extreme environments in the universe, and answer questions about supermassive black hole systems, pulsars and the origin of cosmic rays. It also will study the mystery of powerful explosions known as gamma-ray bursts. Photo credit: NASA/Jim Grossmann

KSC-08pd0782

NASA Image and Video Library

2008-03-21

CAPE CANAVERAL, Fla. --- In the Astrotech payload processing facility, a General Dynamics technician prepares to test the deployment mechanism of the solar arrays on NASA's Gamma-Ray Large Area Space Telescope, or GLAST. The telescope will launch aboard a Delta II rocket May 16 from Launch Pad 17-B on Cape Canaveral Air Force Station. A powerful space observatory, the GLAST will explore the most extreme environments in the universe, and answer questions about supermassive black hole systems, pulsars and the origin of cosmic rays. It also will study the mystery of powerful explosions known as gamma-ray bursts. Photo credit: NASA/Jim Grossmann

Single-pulse x-ray diffraction using polycapillary optics for in situ dynamic diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maddox, B. R., E-mail: maddox3@llnl.gov; Akin, M. C., E-mail: akin1@llnl.gov; Teruya, A.

2016-08-15

Diagnostic use of single-pulse x-ray diffraction (XRD) at pulsed power facilities can be challenging due to factors such as the high flux and brightness requirements for diffraction and the geometric constraints of experimental platforms. By necessity, the x-ray source is usually positioned very close, within a few inches of the sample. On dynamic compression platforms, this puts the x-ray source in the debris field. We coupled x-ray polycapillary optics to a single-shot needle-and-washer x-ray diode source using a laser-based alignment scheme to obtain high-quality x-ray diffraction using a single 16 ns x-ray pulse with the source >1 m from themore » sample. The system was tested on a Mo sample in reflection geometry using 17 keV x-rays from a Mo anode. We also identified an anode conditioning effect that increased the x-ray intensity by 180%. Quantitative measurements of the x-ray focal spot produced by the polycapillary yielded a total x-ray flux on the sample of 3.3 ± 0.5 × 10{sup 7} molybdenum Kα photons.« less

A multi-dataset data-collection strategy produces better diffraction data

PubMed Central

Liu, Zhi-Jie; Chen, Lirong; Wu, Dong; Ding, Wei; Zhang, Hua; Zhou, Weihong; Fu, Zheng-Qing; Wang, Bi-Cheng

2011-01-01

A multi-dataset (MDS) data-collection strategy is proposed and analyzed for macromolecular crystal diffraction data acquisition. The theoretical analysis indicated that the MDS strategy can reduce the standard deviation (background noise) of diffraction data compared with the commonly used single-dataset strategy for a fixed X-ray dose. In order to validate the hypothesis experimentally, a data-quality evaluation process, termed a readiness test of the X-ray data-collection system, was developed. The anomalous signals of sulfur atoms in zinc-free insulin crystals were used as the probe to differentiate the quality of data collected using different data-collection strategies. The data-collection results using home-laboratory-based rotating-anode X-ray and synchrotron X-ray systems indicate that the diffraction data collected with the MDS strategy contain more accurate anomalous signals from sulfur atoms than the data collected with a regular data-collection strategy. In addition, the MDS strategy offered more advantages with respect to radiation-damage-sensitive crystals and better usage of rotating-anode as well as synchrotron X-rays. PMID:22011470

Comparison of ring-focus image profile with predictions for the AXAF VETA-I test

NASA Technical Reports Server (NTRS)

Zissa, David E.

1993-01-01

The X-ray test of the largest pair of nearly cylindrical mirrors for the Advanced X-ray Astrophysics Facility (AXAF) was completed in October 1991 at Marshall Space Flight Center. The test assembly was named the Verification Engineering Test Article I (VETA-I). The ring-focus portion of the test measured the imaging quality of azimuthal sections of VETA-I. This gives information about the core of the on-orbit image. The finite source distance, VETA-I mirror spacing, and VETA-I structural deformation caused the core of the image to be spread over a diameter of nearly 4 arc seconds at the VETA-I overall focus. The results of a preliminary analysis of the ring-focus data and the implications for the on-orbit image of the telescope are discussed. An upper limit for the on-orbit encircled-energy fraction at 1 arc second diameter was determined to be 0.82 at 0.277 keV X-ray energy. This assumes that the bottoms of the mirrors in the VETA-I arrangement are representative of the mirror surfaces and that the on-orbit system would be aligned using a combination of preliminary measurements and predictions for the mirror surface shapes.

Compact and portable X-ray imager system using Medipix3RX

NASA Astrophysics Data System (ADS)

Garcia-Nathan, T. B.; Kachatkou, A.; Jiang, C.; Omar, D.; Marchal, J.; Changani, H.; Tartoni, N.; van Silfhout, R. G.

2017-10-01

In this paper the design and implementation of a novel portable X-ray imager system is presented. The design features a direct X-ray detection scheme by making use of a hybrid detector (Medipix3RX). Taking advantages of the capabilities of the Medipix3RX, like a high resolution, zero dead-time, single photon detection and charge-sharing mode, the imager has a better resolution and higher sensitivity compared to using traditional indirect detection schemes. A detailed description of the system is presented, which consists of a vacuum chamber containing the sensor, an electronic board for temperature management, conditioning and readout of the sensor and a data processing unit which also handles network connection and allow communication with clients by acting as a server. A field programmable gate array (FPGA) device is used to implement the readout protocol for the Medipix3RX, apart from the readout the FPGA can perform complex image processing functions such as feature extraction, histogram, profiling and image compression at high speeds. The temperature of the sensor is monitored and controlled through a PID algorithm making use of a Peltier cooler, improving the energy resolution and response stability of the sensor. Without implementing data compression techniques, the system is capable of transferring 680 profiles/s or 240 images/s in a continuous mode. Implementation of equalization procedures and tests on colour mode are presented in this paper. For the experimental measurements the Medipix3RX sensor was used with a Silicon layer. One of the tested applications of the system is as an X-ray beam position monitor (XBPM) device for synchrotron applications. The XBPM allows a non-destructive real time measurement of the beam position, size and intensity. A Kapton foil is placed in the beam path scattering radiation towards a pinhole camera setup that allows the sensor to obtain an image of the beam. By using profiles of the synchrotron X-ray beam, high frequency movement of the beam position can be studied, up to 340 Hz. The system is capable of realizing an independent energy measure of the beam by using the Medipix3RX variable energy threshold feature.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shedlock, Daniel; Dugan, Edward T.; Jacobs, Alan M.

X-ray backscatter radiography by selective detection (RSD) is a field tested and innovative approach to non-destructive evaluation (NDE). RSD is an enhanced single-side x-ray Compton backscatter imaging (CBI) technique which selectively detects scatter components to improve image contrast and quality. Scatter component selection is accomplished through a set of specially designed detectors with fixed and movable collimators. Experimental results have shown that this NDE technique can be used to detect boric acid deposition on a metallic plate through steel foil reflective insulation commonly covering reactor pressure vessels. The current system is capable of detecting boric acid deposits with sub-millimeter resolution,more » through such insulating materials. Industrial systems have been built for Lockheed Martin Space Co. and NASA. Currently the x-ray backscatter RSD scanning systems developed by the University of Florida are being used to inspect the spray-on foam insulation (SOFI) used on the external tank of the space shuttle. RSD inspection techniques have found subsurface cracking in the SOFI thought to be responsible for the foam debris which separated from the external tank during the last shuttle launch. These industrial scanning systems can be customized for many applications, and a smaller, lighter, more compact unit design is being developed. The smaller design is approximately four inches wide, three inches high, and about 12 inches in length. This smaller RSD system can be used for NDE of areas that cannot be reached with larger equipment. X-ray backscatter RSD is a proven technology that has been tested on a wide variety of materials and applications. Currently the system has been used to inspect materials such as aluminum, plastics, honeycomb laminates, reinforced carbon composites, steel, and titanium. The focus of RSD is for one-sided detection for applications where conventional non-destructive examination methods either will not work or give poor results. Acquired images have clearly shown, for a variety of conditions, that proper selection of x-ray field scatter components leads to a significant improvement in image quality and contrast. Improvements are significant enough in some cases that objects not visible to conventional CBI or transmission radiography become readily discernable with RSD. (authors)« less

A Compton suppressed detector multiplicity trigger based digital DAQ for gamma-ray spectroscopy

NASA Astrophysics Data System (ADS)

Das, S.; Samanta, S.; Banik, R.; Bhattacharjee, R.; Basu, K.; Raut, R.; Ghugre, S. S.; Sinha, A. K.; Bhattacharya, S.; Imran, S.; Mukherjee, G.; Bhattacharyya, S.; Goswami, A.; Palit, R.; Tan, H.

2018-06-01

The development of a digitizer based pulse processing and data acquisition system for γ-ray spectroscopy with large detector arrays is presented. The system is based on 250 MHz 12-bit digitizers, and is triggered by a user chosen multiplicity of Compton suppressed detectors. The logic for trigger generation is similar to the one practised for analog (NIM/CAMAC) pulse processing electronics, while retaining the fast processing merits of the digitizer system. Codes for reduction of data acquired from the system have also been developed. The system has been tested with offline studies using radioactive sources as well as in the in-beam experiments with an array of Compton suppressed Clover detectors. The results obtained therefrom validate its use in spectroscopic efforts for nuclear structure investigations.

Plutonium immobilization can loading FY99 component test report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kriikku, E.

2000-06-01

This report summarizes FY99 Can Loading work completed for the Plutonium Immobilization Project and it includes details about the Helium hood, cold pour cans, Can Loading robot, vision system, magnetically coupled ray cart and lifts, system integration, Can Loading glovebox layout, and an FY99 cost table.

Experimental validation and testing of a NaI boron-lined neutron detector

NASA Astrophysics Data System (ADS)

Metwally, Walid A.; Emam, Amira G.

2018-05-01

Effective neutron detection systems are critical in various nuclear fields. Most of the current detection systems rely on He-3 detectors due to their high neutron cross section. However, the limited sizes and worldwide scarcity of He-3 lead to major research efforts to find alternative neutron detectors. One of the proposed cost-effective alternatives is using boron-lined NaI detectors to detect the gamma ray resulting from the 10B(n,α)7Li reaction. The proposed detector assembly has been experimentally tested and its results were compared with those from a He-3 detector. In addition to detecting the gamma rays from the source and surrounding medium, the boron-lined NaI detector showed a good sensitivity to changes in neutron flux distributions and a higher efficiency when compared to the He-3 detector used.

Porous plug phase separator and superfluid film flow suppression system for the soft x-ray spectrometer onboard ASTRO-H

NASA Astrophysics Data System (ADS)

Ezoe, Yuichiro; Ishikawa, Kumi; Mitsuishi, Ikuyuki; Ohashi, Takaya; Mitsuda, Kazuhisa; Fujimoto, Ryuichi; Murakami, Masahide; Kanao, Kenichi; Yoshida, Seiji; Tsunematsu, Shoji; DiPirro, Michael; Shirron, Peter

2016-07-01

Suppression of super fluid helium flow is critical for the Soft X-ray Spectrometer onboard ASTRO-H (Hitomi). In nominal operation, a small helium gas flow of 30 μg/s must be safely vented and a super fluid film flow must be sufficiently small <2 μg/s. To achieve a life time of the liquid helium, a porous plug phase separator and a film flow suppression system composed of an orifice, a heat exchanger, and knife edge devices are employed. In this paper, design, on-ground testing results and in-orbit performance of the porous plug and the film flow suppression system are described.

Results of a laboratory experiment that tests rotating unbalanced-mass devices for scanning gimbaled payloads and free-flying spacecraft

NASA Technical Reports Server (NTRS)

Alhorn, D. C.; Polites, M. E.

1994-01-01

Rotating unbalanced-mass (RUM) devices are a new way to scan space-based, balloon-borne, and ground-based gimbaled payloads, like x-ray and gamma-ray telescopes. They can also be used to scan free-flying spacecraft. Circular scans, linear scans, and raster scans can be generated. A pair of RUM devices generates the basic scan motion and an auxiliary control system using torque motors, control moment gyros, or reaction wheels keeps the scan centered on the target and produces some complementary motion for raster scanning. Previous analyses and simulation results show that this approach offers significant power savings compared to scanning only with the auxiliary control system, especially with large payloads and high scan frequencies. However, these claims have never been proven until now. This paper describes a laboratory experiment which tests the concept of scanning a gimbaled payload with RUM devices. A description of the experiment is given and test results that prove the concept are presented. The test results are compared with those from a computer simulation model of the experiment and the differences are discussed.

A concept for a soft gamma-ray concentrator using thin-film multilayer structures

NASA Astrophysics Data System (ADS)

Bloser, Peter F.; Shirazi, Farzane; Echt, Olof; Krzanowski, James E.; Legere, Jason S.; McConnell, Mark L.; Tsavalas, John G.; Wong, Emily N.; Aliotta, Paul H.

2016-07-01

We are investigating the use of thin-film, multilayer structures to form optics capable of concentrating soft gamma rays with energies greater than 100 keV, beyond the reach of current grazing-incidence hard X-ray mirrors. Alternating layers of low- and high-density materials (e.g., polymers and metals) will channel soft gamma-ray photons via total external reflection. A suitable arrangement of bent structures will then concentrate the incident radiation to a point. Gamma-ray optics made in this way offer the potential for soft gamma-ray telescopes with focal lengths of less than 10 m, removing the need for formation flying spacecraft and opening the field up to balloon-borne instruments. Following initial investigations conducted at Los Alamos National Laboratory, we have constructed and tested a prototype structure using spin coating combined with magnetron sputtering. We are now investigating whether it is possible to grow such flexible multi-layer structures with the required thicknesses and smoothness more quickly by using magnetron sputter and pulsed laser deposition techniques. We present the latest results of our fabrication and gamma-ray channeling tests, and describe our modeling of the sensitivity of potential concentrator-based telescope designs. If successful, this technology offers the potential for transformational increases in sensitivity while dramatically improving the system-level performance of future high-energy astronomy missions through reduced mass and complexity.

A System Approach to Navy Medical Education and Training. Appendix 18. Radiation Technician.

DTIC Science & Technology

1974-08-31

attrition was forecast to approximate twenty percent, final sample and sub-sample sizes were adjusted accordingly. Stratified random sampling... HYPERTENSIVE INTRAVENOUS PYELOGRAMS 2 ITAKE RENAL LOOPOGRAMI I 3 ITAKE CIXU, I.Eo CONSTANT INFUSION 4 10 RENAL SPLIT FUNCTION TEST, E.G. STAMEY 5...ITAKE PORTAL FILM OF AREA BEING TREATED WITH COBALT 32 [INFORM DOCTOR OF UNEXPECTED X-RAY FINDINGS 33 IREAD X-RAY FILMS FOR TECHNICAL ADEQUACY 34

Simulation and Laboratory results of the Hard X-ray Polarimeter: X-Calibur

NASA Astrophysics Data System (ADS)

Guo, Qingzhen; Beilicke, M.; Kislat, F.; Krawczynski, H.

2014-01-01

X-ray polarimetry promises to give qualitatively new information about high-energy sources, such as binary black hole (BH) systems, Microquasars, active galactic nuclei (AGN), GRBs, etc. We designed, built and tested a hard X-ray polarimeter 'X-Calibur' to be flown in the focal plane of the InFOCuS grazing incidence hard X-ray telescope in 2014. X-Calibur combines a low-Z Compton scatterer with a CZT detector assembly to measure the polarization of 20- 80 keV X-rays making use of the fact that polarized photons Compton scatter preferentially perpendicular to the E field orientation. X-Calibur achieves a high detection efficiency of order unity. We optimized of the design of the instrument based on Monte Carlo simulations of polarized and unpolarized X-ray beams and of the most important background components. We have calibrated and tested X-Calibur extensively in the laboratory at Washington University and at the Cornell High-Energy Synchrotron Source (CHESS). Measurements using the highly polarized synchrotron beam at CHESS confirm the polarization sensitivity of the instrument. In this talk we report on the optimization of the design of the instrument based on Monte Carlo simulations, as well as results of laboratory calibration measurements characterizing the performance of the instrument.

A small-angle x-ray scattering system with a vertical layout.

PubMed

Wang, Zhen; Chen, Xiaowei; Meng, Lingpu; Cui, Kunpeng; Wu, Lihui; Li, Liangbin

2014-12-01

A small-angle x-ray scattering (SAXS) system with a vertical layout (V-SAXS) has been designed and constructed for in situ detection on nanostructures, which is well suitable for in situ study on self-assembly of nanoparticles at liquid interface and polymer processing. A steel-tower frame on a reinforced basement is built as the supporting skeleton for scattering beam path and detector platform, ensuring the system a high working stability and a high operating accuracy. A micro-focus x-ray source combining parabolic three-dimensional multi-layer mirror and scatteringless collimation system provides a highly parallel beam, which allows us to detect the very small angle range. With a sample-to-detector distance of 7 m, the largest measurable length scale is 420 nm in real space. With a large sample zone, it is possible to install different experimental setups such as film stretching machine, which makes the system perfect to follow the microstructures evolution of materials during processing. The capability of the V-SAXS on in situ study is tested with a drying experiment of a free latex droplet, which confirms our initial design.

Pulse pile-up in hard X-ray detector systems. [for solar X-rays

NASA Technical Reports Server (NTRS)

Datlowe, D. W.

1975-01-01

When pulse-height spectra are measured by a nuclear detection system at high counting rates, the probability that two or more pulses will arrive within the resolving time of the system is significant. This phenomenon, pulse pile-up, distorts the pulse-height spectrum and must be considered in the interpretation of spectra taken at high counting rates. A computational technique for the simulation of pile-up is developed. The model is examined in the three regimes where (1) the time between pulses is long compared to the detector-system resolving time, (2) the time between pulses is comparable to the resolving time, and (3) many pulses occur within the resolving time. The technique is used to model the solar hard X-ray experiment on the OSO-7 satellite; comparison of the model with data taken during three large flares shows excellent agreement. The paper also describes rule-of-thumb tests for pile-up and identifies the important detector design factors for minimizing pile-up, i.e., thick entrance windows and short resolving times in the system electronics.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Verburg, J; Bortfeld, T

Purpose: We present a new system to perform prompt gamma-ray spectroscopy during proton pencil-beam scanning treatments, which enables in vivo verification of the proton range. This system will be used for the first clinical studies of this technology. Methods: After successful pre-clinical testing of prompt gamma-ray spectroscopy, a full scale system for clinical studies is now being assembled. Prompt gamma-rays will be detected during patient treatment using an array of 8 detector modules arranged behind a tungsten collimator. Each detector module consists of a lanthanum(III) bromide scintillator, a photomultiplier tube, and custom electronics for stable high voltage supply and signalmore » amplification. A new real-time data acquisition and control system samples the signals from the detectors with analog-to-digital converters, analyses events of interest, and communicates with the beam delivery systems. The timing of the detected events was synchronized to the cyclotron radiofrequency and the pencil-beam delivery. Range verification is performed by matching measured energy- and timeresolved gamma-ray spectra to nuclear reaction models based on the clinical treatment plan. Experiments in phantoms were performed using clinical beams in order to assess the performance of the systems. Results: The experiments showed reliable real-time analysis of more than 10 million detector events per second. The individual detector modules acquired accurate energy- and time-resolved gamma-ray measurements at a rate of 1 million events per second, which is typical for beams delivered with a clinical dose rate. The data acquisition system successfully tracked the delivery of the scanned pencil-beams to determine the location of range deviations within the treatment field. Conclusion: A clinical system for proton range verification using prompt gamma-ray spectroscopy has been designed and is being prepared for use during patient treatments. We anticipate to start a first clinical study in the near future. This work was supported by the Federal Share of program income earned by Massachusetts; General Hospital on C06-CA059267, Proton Therapy Research and Treatment Center.« less

X-ray scattering study

NASA Technical Reports Server (NTRS)

Wriston, R. S.; Froechtenigt, J. F.

1972-01-01

A soft X-ray glancing incidence telescope mirror and a group of twelve optical flat samples were used to study the scattering of X-rays. The mirror was made of Kanigen coated beryllium and the images produced were severely limited by scattering of X-rays. The best resolution attained was about fifteen arc seconds. The telescope efficiency was found to be 0.0006. The X-ray beam reflected from the twelve optical flat samples was analyzed by means of a long vacuum system of special design for these tests. The scattering then decreased with increasing angle of incidence until a critical angle was passed. At larger angles the scattering increased again. The samples all scattered more at 44 A than at 8 A. Metal samples were found to have about the same scattering at 44 A but greater scattering at 8 A than glass samples.

Progress of nanopositioning stages development for hard x-ray nanofocusing and coherence preservation optics at the APS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shu, Deming

2015-07-01

Customized flexure mechanisms and precision thermal expansion compensation are needed for the development of nanopositioning stages for hard x-ray nanofocusing and coherence preservation optics at the APS. Recent progress of such stage development is summarized in this paper, which includes: stages designed for alignment apparatus for K-B mirrors with 20 - 50 nm focal spot; alignment apparatus for six Fresnel zone plates stacking with 20 nm focal spot; stages for switchable multiple nanofocusing system; UHV hard x-ray monochromators for coherence related applications; and four-crystal hard x-ray split-and-delay line with coherence preservation. Preliminary test results for mechanical performance of these nanopositioningmore » stages are also discussed in this paper.« less

Using the USU ionospheric model to predict radio propagation through a simulated ionosphere

NASA Astrophysics Data System (ADS)

Huffines, Gary R.

1990-12-01

To evaluate the capabilities of communication, navigation, and defense systems utilizing electromagnetic waves which interact with the ionosphere, a three-dimensional ray tracing program was used. A simple empirical model (Chapman function) and a complex physical model (Schunk and Sojka model) were used to compare the representation of ionospheric conditions. Four positions were chosen to test four different features of the Northern Hemispheric ionosphere. It seems that decreasing electron density has little or no effect on the horizontal components of the ray path while increasing electron density causes deviations in the ray path. It was also noted that rays in the physical model's mid-latitude trough region escaped the ionosphere for all frequencies used in this study.

Feasibility study of a low-energy gamma ray system for measuring quantity and flow rate of slush hydrogen

NASA Technical Reports Server (NTRS)

Singh, Jag J.; Shen, Chih-Ping; Sprinkle, Danny R.

1992-01-01

As part of a study to demonstrate the suitability of an X-ray or gamma ray probe for monitoring the quality and flow rate of slush hydrogen, mass attenuation coefficients for Cd-109 X- and gamma radiation in five chemical compounds were measured. The Ag-109 K rays were used for water and acetic acid, whereas E3 transition from the first excited state at 87.7 keV in Ag-109 provided the probe radiation for bromobenzene, alpha (exp 2) chloroisodurene, and cetyl bromide. Measurements were made for a single phase (gas, liquid, solid) as well as mixed phases (liquid plus solid) in all cases. It was shown that the mass attenuation coefficient for the selected radiations is independent of the phase of the test fluids or phase ratios in the case of mixed phase fluids. Described here are the procedure and the results for the five fluid systems investigated.

Modern aerial gamma-ray spectrometry and regional potassium map of the conterminous United States

USGS Publications Warehouse

Duval, Joseph S.

1990-01-01

The aerial gamma-ray data were obtained as part of the National Uranium Resource Evaluation (NURE) Program sponsored by the U.S. Department of Energy during the period 1975-1983. References for the Open-File Reports that describe the surveys and data collection can be found in Bendix Field Engineering Corp. (1983). The aerial surveys were flown by contractors using fixed-wing and helicopter systems with 33-50 L (liters) of thallium-activated sodium iodide (NaI (TI)) crystals. The nominal survey altitude used is 122 m. The survey lines were generally east-west with line spacings of 1.6-10 km. Tie lines were flown perpendicular to the flight lines at intervals of 16- 30 km. The data were corrected for background from aircraft contamination and cosmic rays, altitude variations, airborne 214Bi, and Compton scattering. The gamma-ray systems were calibrated using the calibrations pads at Grand Junction, Colorado (Ward, 1978 ) and the dynamic test strip at Lake Mead, Arizona (Geodata International, Inc., 1977).  

Comprehensive clinical commissioning and validation of the RayStation treatment planning system for proton therapy with active scanning and passive treatment techniques.

PubMed

Bäumer, C; Geismar, D; Koska, B; Kramer, P H; Lambert, J; Lemke, M; Plaude, S; Pschichholz, L; Qamhiyeh, S; Schiemann, A; Timmermann, B; Vermeren, X

2017-11-01

To commission the treatment planning system (TPS) RayStation for proton therapy including beam models for spot scanning and for uniform scanning. Tests consist of procedures from ESTRO booklet number 7, the German DIN for constancy checks of TPSs, and extra tests checking the dose perturbation function. The dose distributions within patients were verified in silico by a comparison of 65 clinical treatment plans with the TPS XiO. Dose-volume parameters, dose differences, and three-dimensional gamma-indices serve as measures of similarity. The monthly constancy checks of Raystation have been automatized with a script. The basic functionality of the software complies with ESTRO booklet number 7. For a few features minor enhancements are suggested. The dose distribution in RayStation agrees with the calculation in XiO. This is supported by a gamma-index (3mm/3%) pass rate of >98.9% (median over 59 plans) for the volume within the 20% isodose line and a difference of <0.3% of V 95 of the PTV (median over 59 plans). If spot scanning is used together with a range shifter, the dose level calculated by RayStation can be off by a few percent. RayStation can be used for the creation of clinical proton treatment plans. Compared to XiO RayStation has an improved modelling of the lateral dose fall-off in passively delivered fields. For spot scanning fields with range shifter blocks an empirical adjustment of monitor units is required. The computation of perturbed doses also allows the evaluation of the robustness of a treatment plan. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Effect of X-ray exposure on the pharmaceutical quality of drug tablets using X-ray inspection equipment.

PubMed

Uehara, Kazuaki; Tagami, Tatsuaki; Miyazaki, Itaru; Murata, Norikazu; Takahashi, Yoshifumi; Ohkubo, Hiroshi; Ozeki, Tetsuya

2015-06-01

X-ray inspection equipment is widely used to detect missing materials and defective goods in opaque containers. Its application has been expanded to the pharmaceutical industry to detect the presence of drug tablets in aluminum foil press-through packaging. However, the effect of X-rays on the pharmaceutical quality of drug tablets is not well known. In this study, the effect of X-rays on the pharmaceutical quality of drug tablets was investigated. Exposure of acetaminophen, loxoprofen and mefenamic acid tablets to X-ray doses of 0.34 mGy (thrice the dose by X-ray scanning) to 300 Gy (maximum dose from our X-ray equipment) was demonstrated, and the samples were evaluated by formulation tests. Exposure to X-rays did not affect the pharmaceutical quality of the drug content. The samples exposed to X-rays exhibited almost the same profile in formulation tests (dissolution test, disintegrating test and hardness test) as control samples (0 Gy). The combination of X-ray exposure with accelerated temperature and humidity tests (six months) also did not affect the pharmaceutical quality. The color change of light-sensitive drugs (nifedipine and furosemide tablets) after X-ray exposure was negligible (< 1.0). In contrast, tablet color was remarkably changed by light from a D65 lamp. The X-ray scanning and X-ray exposure under our experimental conditions did not affect the pharmaceutical quality of drug tablets.

Using Simulations of Black Holes to Study General Relativity and the Properties of Inner Accretion Flow

NASA Astrophysics Data System (ADS)

Hoormann, Janie Katherine

2016-06-01

While Albert Einstein's theory of General Relativity (GR) has been tested extensively in our solar system, it is just beginning to be tested in the strong gravitational fields that surround black holes. As a way to study the behavior of gravity in these extreme environments, I have used and added to a ray-tracing code that simulates the X-ray emission from the accretion disks surrounding black holes. In particular, the observational channels which can be simulated include the thermal and reflected spectra, polarization, and reverberation signatures. These calculations can be performed assuming GR as well as four alternative spacetimes. These results can be used to see if it is possible to determine if observations can test the No-Hair theorem of GR which states that stationary, astrophysical black holes are only described by their mass and spin. Although it proves difficult to distinguish between theories of gravity, it is possible to exclude a large portion of the possible deviations from GR using observations of rapidly spinning stellar mass black holes such as Cygnus X-1. The ray-tracing simulations can furthermore be used to study the inner regions of black hole accretion flows. I examined the dependence of X-ray reverberation observations on the ionization of the disk photosphere. My results show that X-ray reverberation and X-ray polarization provides a powerful tool to constrain the geometry of accretion disks which are too small to be imaged directly. The second part of my thesis describes the work on the balloon-borne X-Calibur hard X-ray polarimetry mission and on the space-borne PolSTAR polarimeter concept.

Adaptive optics based non-null interferometry for optical free form surfaces test

NASA Astrophysics Data System (ADS)

Zhang, Lei; Zhou, Sheng; Li, Jingsong; Yu, Benli

2018-03-01

An adaptive optics based non-null interferometry (ANI) is proposed for optical free form surfaces testing, in which an open-loop deformable mirror (DM) is employed as a reflective compensator, to compensate various low-order aberrations flexibly. The residual wavefront aberration is treated by the multi-configuration ray tracing (MCRT) algorithm. The MCRT algorithm based on the simultaneous ray tracing for multiple system models, in which each model has different DM surface deformation. With the MCRT algorithm, the final figure error can be extracted together with the surface misalignment aberration correction after the initial system calibration. The flexible test for free form surface is achieved with high accuracy, without auxiliary device for DM deformation monitoring. Experiments proving the feasibility, repeatability and high accuracy of the ANI were carried out to test a bi-conic surface and a paraboloidal surface, with a high stable ALPAOTM DM88. The accuracy of the final test result of the paraboloidal surface was better than 1/20 Μ PV value. It is a successful attempt in research of flexible optical free form surface metrology and would have enormous potential in future application with the development of the DM technology.

Astronomy helps advance medical diagnosis techniques

NASA Astrophysics Data System (ADS)

2001-11-01

Effective treatment of cancer relies on the early detection and removal of cancerous cells. Unfortunately, this is when they are hardest to spot. In the case of breast cancer, now the most prevalent form of cancer in the United Kingdom, cancer cells tend to congregate in the lymph nodes, from where they can rapidly spread throughout the rest of the body. Current medical equipment can give doctors only limited information on tissue health. A surgeon must then perform an exploratory operation to try to identify the diseased tissue. If that is possible, the diseased tissue will be removed. If identification is not possible, the doctor may be forced to take away the whole of the lymphatic system. Such drastic treatment can then cause side effects, such as excessive weight gain, because it throws the patient's hormones out of balance. Now, members of the Science Payloads Technology Division of the Research and Science Support Department, at ESA's science, technology and engineering research centre (ESTEC) in the Netherlands, have developed a new X-ray camera that could make on-the-spot diagnoses and pinpoint cancerous areas to guide surgeons. Importantly, it would be a small device that could be used continuously during operations. "There is no photography involved in the camera we envisage. It will be completely digital, so the surgeon will study the whole lymphatic system and the potentially cancerous parts on his monitor. He then decides which parts he removes," says Dr. Tone Peacock, Head of the Science Payloads Technology Division. The ESA team were trying to find a way to make images using high-energy X-rays because some celestial objects give out large quantities of X-rays but little visible light. To see these, astronomers need to use X-ray cameras. Traditionally, this has been a bit of a blind spot for astronomers. ESA's current X-ray telescope, XMM-Newton, is in orbit now, observing low energy, so-called 'soft' X-rays. European scientists have always wanted to follow up XMM-Newton's success with a satellite called XEUS. It would be capable of taking images of the high-energy 'hard' X-rays but a reliable camera has eluded them - until now. For the first time, the ESTEC researchers have produced a microchip, similar to that found in a household video camera but capable of detecting hard X-rays instead of visible light. The key is that, instead of silicon, the new chip is made from a chemical compound called epitaxial gallium arsenide. This new material was developed under the ESA leadership of Dr Marcos Bavdaz to the very demanding requirements of such hard X-ray sensors. The prototype sensor has now successfully completed its extensive tests at a German X-ray test facility (HASYLAB). It may seem surprising that medical imaging is similar to observing high energy X-rays from space. However, hard X-rays are the only type that will pass through the human body. Dr Alan Owens, who is closely involved in the research at ESA, explains: "For the lymphatic system a radioactive tracer which emits X-rays is injected into or near the breast tumour. The tracer focuses on those parts of the system which are cancerous. With a small camera it is therefore possible to image this cancerous tissue during surgery." The ESA team were aware, from an early stage, that the work they were doing could lead to better medical equipment and sought expert advice. "We are talking to the people at Leiden University Medical Centre," explains Owens. "Also they can test and evaluate what we produce." A small lightweight X-ray camera would be a very important addition to the set of tools available to the surgeon. Having made the basic camera sensor, the next stage in this work is to develop a system to send the images to television screens in real time. "We are developing that now with our industrial partners, such as Metorex, a research and development company in Finland," says Peacock. Once ESA, which is a non-profit organisation, has developed the technology to make this X-ray camera work, its task is done. The industrial partners will take over, producing a camera for medical use. ESA will adapt its design to provide European astronomers with a new view of the Universe.

Real-Time Processing System for the JET Hard X-Ray and Gamma-Ray Profile Monitor Enhancement

NASA Astrophysics Data System (ADS)

Fernandes, Ana M.; Pereira, Rita C.; Neto, André; Valcárcel, Daniel F.; Alves, Diogo; Sousa, Jorge; Carvalho, Bernardo B.; Kiptily, Vasily; Syme, Brian; Blanchard, Patrick; Murari, Andrea; Correia, Carlos M. B. A.; Varandas, Carlos A. F.; Gonçalves, Bruno

2014-06-01

The Joint European Torus (JET) is currently undertaking an enhancement program which includes tests of relevant diagnostics with real-time processing capabilities for the International Thermonuclear Experimental Reactor (ITER). Accordingly, a new real-time processing system was developed and installed at JET for the gamma-ray and hard X-ray profile monitor diagnostic. The new system is connected to 19 CsI(Tl) photodiodes in order to obtain the line-integrated profiles of the gamma-ray and hard X-ray emissions. Moreover, it was designed to overcome the former data acquisition (DAQ) limitations while exploiting the required real-time features. The new DAQ hardware, based on the Advanced Telecommunication Computer Architecture (ATCA) standard, includes reconfigurable digitizer modules with embedded field-programmable gate array (FPGA) devices capable of acquiring and simultaneously processing data in real-time from the 19 detectors. A suitable algorithm was developed and implemented in the FPGAs, which are able to deliver the corresponding energy of the acquired pulses. The processed data is sent periodically, during the discharge, through the JET real-time network and stored in the JET scientific databases at the end of the pulse. The interface between the ATCA digitizers, the JET control and data acquisition system (CODAS), and the JET real-time network is provided by the Multithreaded Application Real-Time executor (MARTe). The work developed allowed attaining two of the major milestones required by next fusion devices: the ability to process and simultaneously supply high volume data rates in real-time.

Necrotizing vasculitis

MedlinePlus

The health care provider will do a complete physical exam. A nervous system (neurological) exam may show signs of nerve damage. Tests that may be done include: Complete blood count, comprehensive chemistry panel, and urinalysis Chest x-ray C-reactive ...

5 MV 30 mA industrial electron processing system

NASA Astrophysics Data System (ADS)

Hoshi, Y.; Mizusawa, K.

1991-05-01

Industrial electron beam processing systems have been in use in various application fields such as: improving heat resistivity of wire insulation; controlling quality of automobile rubber tires and melt index characteristics of PE foams; and curing paintings or printing inks. Recently, there has come up a need for electron beam with an energy higher than 3 MV in order to disinfect salmonella in chicken meat, to kill bugs in fruits, and to sterilize medical disposables. To meet this need we developed a 5 MV 30 mA electron processing system with an X-ray conversion target. The machine was tested in NHV's plant in Kyoto at continuous operation of full voltage and full current. It proved to be very steady in operation with a high efficiency (as much as 72%). Also, the X-ray target was tested in a continuous run of 5 MV 30 mA (150 kW). It proved to be viable in industrial utilization. This paper introduces the process and the results of the development.

Detection of Illicit Drugs with the EURITRACK System

NASA Astrophysics Data System (ADS)

Perot, B.; Carasco, C.; Valkovic, V.; Sudac, D.; Franulovic, A.

2009-03-01

The EURopean Illicit TRAfficking Countermeasures Kit (EURITRACK) inspection system has been developed within the 6th EU Framework Program to complement X-ray scanners in the detection of explosives and other illicit materials hidden in cargo containers. Gamma rays are produced inside the cargo materials by 14 MeV tagged neutron beams, which yields information about the chemical composition of the transported goods. In the beginning of year 2007, the EURITRACK system was implemented in the Seaport of Rijeka, Croatia, primarily to carry out a demonstration using real containers to conduct a series of detection tests. This article reports tests performed with real samples of illicit drugs hidden in a metallic cargo with an average density of 0.2 g/cm3. Heroin and cocaine have been distinguished from benign substances based on their chemical composition. Marijuana, which chemical composition is similar to benign materials, cannot be distinguished from common organic goods. However, the detection of an unexpected organic substance inside the metallic cargo indicates that a suspicious object has been hidden in the container.

A library least-squares approach for scatter correction in gamma-ray tomography

NASA Astrophysics Data System (ADS)

Meric, Ilker; Anton Johansen, Geir; Valgueiro Malta Moreira, Icaro

2015-03-01

Scattered radiation is known to lead to distortion in reconstructed images in Computed Tomography (CT). The effects of scattered radiation are especially more pronounced in non-scanning, multiple source systems which are preferred for flow imaging where the instantaneous density distribution of the flow components is of interest. In this work, a new method based on a library least-squares (LLS) approach is proposed as a means of estimating the scatter contribution and correcting for this. The validity of the proposed method is tested using the 85-channel industrial gamma-ray tomograph previously developed at the University of Bergen (UoB). The results presented here confirm that the LLS approach can effectively estimate the amounts of transmission and scatter components in any given detector in the UoB gamma-ray tomography system.

A Preliminary Research on the Development of the Hard X-Ray Imaging Telescope

NASA Astrophysics Data System (ADS)

Zheng, C. X.; Cai, M. S.; Hu, Y. M.; Huang, Y. Y.; Gong, Y. Z.

2014-03-01

Since the 1860s, astronomers have explored a new field with the discovery of X-ray. Instead of the conventional imaging technique by using mirrors or lens, which can not work in the high-energy bands, direct imaging, coded aperture, and Fourier transform are used for the high-energy imaging. It can be implemented in various hardware configurations, among which the spatial modulation collimator are widely used. We adopt the grating collimator based on Fourier transform that is discussed in detail. This paper makes an investigation on the fabrication process of grating. The key components of the hard X-ray telescope based on the spatial modulation are developed, which contains 8 CsI-detector modules, 8-channel shaping amplifiers, and data acquisition system. The preliminary test results of readout electronics system are obtained.

The Advanced Gamma-ray Imaging System (AGIS): Focal Plane Detectors

NASA Astrophysics Data System (ADS)

Mukherjee, Reshmi; Byrum, K.; Drake, G.; Falcone, A.; Funk, S.; Horan, D.; Tajima, H.; Wagner, B.; Williams, D.

2008-04-01

Report of the Focal Plane Instrumentation Working Group, AGIS collaboration: The Advanced Gamma-ray Imaging System (AGIS) is a concept for the next generation instrument in ground-based very high energy gamma-ray astronomy. It has the goal of achieving significant improvement in sensitivity over current experiments. One of the main requirements for AGIS will be to achieve higher angular resolution than current imaging atmospheric Cherenkov telescopes (IACTs). Simulations show that a substantial improvement in angular resolution may be achieved if the pixel size is reduced to 0.05 deg, below that of current IACTs. Reducing the cost per channel and improving reliability and modularity are other important considerations. Here we present several alternatives being considered for AGIS, including both silicon photomultipliers (SiPMs) and multi-anode photomultipliers (MAPMTs) and summarize results from feasibility testing by various AGIS photodetector group members.

Evaluation of nondestructive testing techniques for the space shuttle nonmetallic thermal protection system

NASA Technical Reports Server (NTRS)

Tiede, D. A.

1972-01-01

A program was conducted to evaluate nondestructive analysis techniques for the detection of defects in rigidized surface insulation (a candidate material for the Space Shuttle thermal protection system). Uncoated, coated, and coated and bonded samples with internal defects (voids, cracks, delaminations, density variations, and moisture content), coating defects (holes, cracks, thickness variations, and loss of adhesion), and bondline defects (voids and unbonds) were inspected by X-ray radiography, acoustic, microwave, high-frequency ultrasonic, beta backscatter, thermal, holographic, and visual techniques. The detectability of each type of defect was determined for each technique (when applicable). A possible relationship between microwave reflection measurements (or X-ray-radiography density measurements) and the tensile strength was established. A possible approach for in-process inspection using a combination of X-ray radiography, acoustic, microwave, and holographic techniques was recommended.

KSC-99pc0165

NASA Image and Video Library

1999-02-06

Cradled in the cargo hold of a tractor-trailer rig called the Space Cargo Transportation System, the Chandra X-ray Observatory reaches the Vertical Processing Facility (VPF). Chandra arrived at the Shuttle Landing Facility on Thursday, Feb. 4, aboard an Air Force C-5 Galaxy aircraft. In the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

KSC-99pc0166

NASA Image and Video Library

1999-02-06

Cradled in the cargo hold of a tractor-trailer rig called the Space Cargo Transportation System, the Chandra X-ray Observatory waits to be moved inside the Vertical Processing Facility (VPF). Chandra arrived at the Shuttle Landing Facility on Thursday, Feb. 4, aboard an Air Force C-5 Galaxy aircraft. In the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

On the Corrosion Performance of Monel 400 in Molten LiCl-Li2O-Li at 923 K

NASA Astrophysics Data System (ADS)

Phillips, William; Merwin, Augustus; Chidambaram, Dev

2018-06-01

The corrosion resistance of a Ni-Cu alloy, Monel 400, in molten LiCl-Li2O-Li at 923 K (650 °C) was investigated. Exposure testing of Monel 400 samples submerged in molten LiCl-2 wt pct Li2O solutions with Li concentrations between zero and 1 wt pct was performed at 923 K (650°C) for 20 hours. Post exposure surface analysis was performed using X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, optical microscopy, micro-Vickers hardness testing, and X-ray photoelectron spectroscopy, while inductively coupled plasma optical emission spectroscopy was used to quantify the rate of material leaching. The extent of material degradation was observed to be strongly correlated to the concentration of metallic Li in the molten LiCl-Li2O system.

Inorganic fullerene-like tungsten disulfide nanocoating for friction reduction of nickel-titanium alloys.

PubMed

Samorodnitzky-Naveh, Gili R; Redlich, Meir; Rapoport, Lev; Feldman, Yishay; Tenne, Reshef

2009-12-01

To fabricate a friction-reducing coating onto different nickel-titanium (NiTi) substrates using inorganic fullerene-like tungsten disulfide (IF-WS(2)) nanoparticles and to estimate in vitro friction reducing extent of the coating. Different NiTi substrates were coated with cobalt and IF-WS(2) nanoparticles film by the electrodeposition procedure. Coating composition analyses was made by scanning-electron microscopy, energy dispersive x-ray spectroscopy, x-ray powder diffractometry and x-ray photoelectron spectroscopy. Friction evaluation was carried out using standard tribological tests and an Instron system. Stable and well-adhered cobalt + IF-WS(2) coating of the NiTi substrates was obtained. Friction tests presented up to 66% reduction of the friction coefficient. NiTi alloy is widely used for many medical appliances; hence, this unique friction-reducing coating could be implemented to provide better manipulation and lower piercing rates.

Temperature Measurements in Compressed and Uncompressed SPECTOR Plasmas at General Fusion

NASA Astrophysics Data System (ADS)

Young, William; Carter, Neil; Howard, Stephen; Carle, Patrick; O'Shea, Peter; Fusion Team, General

2017-10-01

Accurate temperature measurements are critical to establishing the behavior of General Fusion's SPECTOR plasma injector, both before and during compression. As compression tests impose additional constraints on diagnostic access to the plasma, a two-color, filter-based soft x-ray electron temperature diagnostic has been implemented. Ion Doppler spectroscopy measurements also provide impurity ion temperatures on compression tests. The soft x-ray and ion Doppler spectroscopy measurements are being validated against a Thomson scattering system on an uncompressed version of SPECTOR with more diagnostic access. The multipoint Thomson scattering diagnostic also provides up to a six point temperature and density profile, with the density measurements validated against a far infrared interferometer. Temperatures above 300 eV have been demonstrated to be sustained for over 500 microseconds in uncompressed plasmas. Optimization of soft x-ray filters is ongoing, in order to balance blocking of impurity line radiation with signal strength.

A Coordinated X-Ray and Optical Campaign of the Nearest Massive Eclipsing Binary, Delta Orionis Aa. I. Overview of the X-Ray Spectrum

NASA Technical Reports Server (NTRS)

Corcoran, M. F.; Nicholas, J. S.; Pablo, H.; Shenar, T.; Pollock, A. M. T.; Waldron, W. L.; Moffat, A. F. J.; Richardson, N. D.; Russell, C. M. P.; Hamaguchi, K.;

A COORDINATED X-RAY AND OPTICAL CAMPAIGN OF THE NEAREST MASSIVE ECLIPSING BINARY, δ ORIONIS Aa. I. OVERVIEW OF THE X-RAY SPECTRUM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Corcoran, M. F.; Hamaguchi, K.; Nichols, J. S.

2015-08-20

We present an overview of four deep phase-constrained Chandra HETGS X-ray observations of δ Ori A. Delta Ori A is actually a triple system that includes the nearest massive eclipsing spectroscopic binary, δ Ori Aa, the only such object that can be observed with little phase-smearing with the Chandra gratings. Since the fainter star, δ Ori Aa2, has a much lower X-ray luminosity than the brighter primary (δ Ori Aa1), δ Ori Aa provides a unique system with which to test the spatial distribution of the X-ray emitting gas around δ Ori Aa1 via occultation by the photosphere of, andmore » wind cavity around, the X-ray dark secondary. Here we discuss the X-ray spectrum and X-ray line profiles for the combined observation, having an exposure time of nearly 500 ks and covering nearly the entire binary orbit. The companion papers discuss the X-ray variability seen in the Chandra spectra, present new space-based photometry and ground-based radial velocities obtained simultaneously with the X-ray data to better constrain the system parameters, and model the effects of X-rays on the optical and UV spectra. We find that the X-ray emission is dominated by embedded wind shock emission from star Aa1, with little contribution from the tertiary star Ab or the shocked gas produced by the collision of the wind of Aa1 against the surface of Aa2. We find a similar temperature distribution to previous X-ray spectrum analyses. We also show that the line half-widths are about 0.3−0.5 times the terminal velocity of the wind of star Aa1. We find a strong anti-correlation between line widths and the line excitation energy, which suggests that longer-wavelength, lower-temperature lines form farther out in the wind. Our analysis also indicates that the ratio of the intensities of the strong and weak lines of Fe xvii and Ne x are inconsistent with model predictions, which may be an effect of resonance scattering.« less

Gamma Ray Observatory (GRO) dynamics simulator requirements and mathematical specifications, revision 1

NASA Technical Reports Server (NTRS)

Harman, R.; Blejer, D.

1990-01-01

The requirements and mathematical specifications for the Gamma Ray Observatory (GRO) Dynamics Simulator are presented. The complete simulator system, which consists of the profie subsystem, simulation control and input/output subsystem, truth model subsystem, onboard computer model subsystem, and postprocessor, is described. The simulator will be used to evaluate and test the attitude determination and control models to be used on board GRO under conditions that simulate the expected in-flight environment.

A Classical Nova Explosion in a Binary System with B[e] Star

NASA Astrophysics Data System (ADS)

Filippova, E.; Revnivtsev, M.; Lutovinov, A.

2011-09-01

The description of a thermonuclear runaway on a white dwarf, which causes a Classical Nova (CN) explosion, has several uncertainties. Observational tests of models are challenging because the majority of CNe are observed in optical and NIR spectral bands days after the onset of the explosion. We propose to use the properties of the X-ray emission of CNe for these tests. We have developed a model for the 1998 CN explosion in the binary system CI Cam. According to the adopted model the stellar wind from the optical component (a B[e] star), heated by a strong shock wave that was produced when matter was ejected from the white dwarf as the result of a thermonuclear explosion on its surface, is the source of X-ray emission in the standard X-ray band (˜ 2 - 10 keV). We use this model to explain the behaviour of the X-ray luminosity and of the mean temperature of the heated material during the explosion, and obtain velocity and mass estimates of the ejected matter from the WD surface. Discrepancies between model and observations, for example the slower decline of the theoretical luminosity compared to the observed one, are likely caused by the rough assumption of spherical symmetry. Using 3D calculations we find possible density perturbations (accretion wakes) that can reconcile theory with observations.

Test of hadronic interaction models with the KASCADE-Grande muon data

NASA Astrophysics Data System (ADS)

Arteaga-Velázquez, J. C.; Apel, W. D.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuchs, B.; Fuhrmann, D.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Mayer, H. J.; Melissas, M.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schoo, S.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.

2013-06-01

KASCADE-Grande is an air-shower observatory devoted for the detection of cosmic rays with energies in the interval of 1014 - 1018 eV, where the Grande array is responsible for the higher energy range. The experiment comprises different detection systems which allow precise measurements of the charged, electron and muon numbers of extensive air-showers (EAS). These data is employed not only to reconstruct the properties of the primary cosmic-ray particle but also to test hadronic interaction models at high energies. In this contribution, predictions of the muon content of EAS from QGSJET II-2, SIBYLL 2.1 and EPOS 1.99 are confronted with the experimental measurements performed with the KASCADE-Grande experiment in order to test the validity of these hadronic models commonly used in EAS simulations.

Liquid-explosives scanners stand trial in airports

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matthews, Jermey N. A.

Air passengers may once more be allowed to pack beverages, lotions, and hair spray in their carry-on luggage, if imaging technologies to detect liquid explosives can prove their worth. Several competing systems, including multi-energy x-ray systems and a low-field magnetic resonance imaging (MRI) scanner, are undergoing field tests at some airports worldwide.

A normal incidence high resolution X-ray telescope for solar coronal observations

NASA Technical Reports Server (NTRS)

Golub, Leon

1987-01-01

The preflight preparation of the multilayer mirror fabrication and testing, integration and testing, and WSMR activities are described. Post-flight analysis shows that all payload systems and subsystems performed well within acceptable limits, with the sole exception of the light-blocking prefilters. Suggested corrective actions were discussed. Refurbishment and reflight are then described.

Fracture Toughness, Mechanical Property, And Chemical Characterization Of A Critical Modification To The NASA SLS Solid Booster Internal Material System

NASA Technical Reports Server (NTRS)

Pancoast, Justin; Garrett, William; Moe, Gulia

2015-01-01

A modified propellant-liner-insulation (PLI) bondline in the Space Launch System (SLS) solid rocket booster required characterization for flight certification. The chemical changes to the PLI bondline and the required additional processing have been correlated to mechanical responses of the materials across the bondline. Mechanical properties testing and analyses included fracture toughness, tensile, and shear tests. Chemical properties testing and analyses included Fourier transform infrared (FTIR) spectroscopy, cross-link density, high-performance liquid chromatography (HPLC), gas chromatography (GC), gel permeation chromatography (GPC), and wave dispersion X-ray fluorescence (WDXRF). The testing identified the presence of the expected new materials and found the functional bondline performance of the new PLI system was not significantly changed from the old system.

Flight qualified solid argon cooler for the BBXRT instrument. [Broad Band X Ray Telescope for ASTRO-1 payload

NASA Technical Reports Server (NTRS)

Cygnarowicz, Thomas A.; Schein, Michael E.; Lindauer, David A.; Scarlotti, Roger; Pederson, Robert

1990-01-01

A solid argon cooler (SAC) for attached Shuttle payloads has been developed and qualified to meet the need for low cost cooling of flight instruments to the temperature range of 60-120 K. The SACs have been designed and tested with the intent of flying them up to five times. Two coolers, as part of the Broad Band X-ray Telescope (BBXRT) instrument on the ASTRO-1 payload, are awaiting launch on Space Shuttle mission STS-35. This paper describes the design, testing and performance of the SAC and its vacuum maintenance system (VMS), used to maintain the argon as a solid during launch delays of up to 5 days. BBXRT cryogen system design features used to satisfy Shuttle safety requirements are discussed, along with SAC ground servicing equipment (GSE) and procedures used to fill, freeze and subcool the argon.

Investigation of periodically driven systems by x-ray absorption spectroscopy using asynchronous data collection mode

NASA Astrophysics Data System (ADS)

Singh, H.; Donetsky, D.; Liu, J.; Attenkofer, K.; Cheng, B.; Trelewicz, J. R.; Lubomirsky, I.; Stavitski, E.; Frenkel, A. I.

2018-04-01

We report the development, testing, and demonstration of a setup for modulation excitation spectroscopy experiments at the Inner Shell Spectroscopy beamline of National Synchrotron Light Source - II. A computer algorithm and dedicated software were developed for asynchronous data processing and analysis. We demonstrate the reconstruction of X-ray absorption spectra for different time points within the modulation pulse using a model system. This setup and the software are intended for a broad range of functional materials which exhibit structural and/or electronic responses to the external stimulation, such as catalysts, energy and battery materials, and electromechanical devices.

Portable X-ray Fluorescence Unit for Analyzing Crime Scenes

NASA Astrophysics Data System (ADS)

Visco, A.

2003-12-01

Goddard Space Flight Center and the National Institute of Justice have teamed up to apply NASA technology to the field of forensic science. NASA hardware that is under development for future planetary robotic missions, such as Mars exploration, is being engineered into a rugged, portable, non-destructive X-ray fluorescence system for identifying gunshot residue, blood, and semen at crime scenes. This project establishes the shielding requirements that will ensure that the exposure of a user to ionizing radiation is below the U.S. Nuclear Regulatory Commission's allowable limits, and also develops the benchtop model for testing the system in a controlled environment.

A novel method for NDT applications using NXCT system at the Missouri University of Science & Technology

NASA Astrophysics Data System (ADS)

Sinha, Vaibhav; Srivastava, Anjali; Koo Lee, Hyoung

2014-06-01

A novel method for non-destructive analysis has been developed using a neutron/X-ray combined computed tomography (NXCT) system at the Missouri University of Science and Technology Reactor (MSTR). This imaging system takes advantage of the fact that neutrons and X-rays have characteristically different interactions with same materials. NXCT fuses the imaging capabilities of both systems at one location and allows instant evaluation for nondestructive testing (NDT) applications. This technique promises viable advances in the field of NDT. In this paper, the complete design criteria and procedures are provided. The described design criteria and procedures can effectively be utilized to design and develop advanced combined computed tomography system. The successful operation of the high resolution X-ray and neutron computed tomography has been demonstrated in this paper. The utility and importance of the NXCT system has been shown by nondestructive evaluation of various phantoms constituting different materials, geometrical, structural and compositional information. The concept of NXCT can be useful for concealed material detection, material characterization, investigation of complex geometries involving different atomic number materials and real time imaging for in-situ studies.

Learning without labeling: domain adaptation for ultrasound transducer localization.

PubMed

Heimann, Tobias; Mountney, Peter; John, Matthias; Ionasec, Razvan

2013-01-01

The fusion of image data from trans-esophageal echography (TEE) and X-ray fluoroscopy is attracting increasing interest in minimally-invasive treatment of structural heart disease. In order to calculate the needed transform between both imaging systems, we employ a discriminative learning based approach to localize the TEE transducer in X-ray images. Instead of time-consuming manual labeling, we generate the required training data automatically from a single volumetric image of the transducer. In order to adapt this system to real X-ray data, we use unlabeled fluoroscopy images to estimate differences in feature space density and correct covariate shift by instance weighting. An evaluation on more than 1900 images reveals that our approach reduces detection failures by 95% compared to cross validation on the test set and improves the localization error from 1.5 to 0.8 mm. Due to the automatic generation of training data, the proposed system is highly flexible and can be adapted to any medical device with minimal efforts.

STARLIFE - An International Campaign to Study the Role of Galactic Cosmic Radiation in Astrobiological Model Systems

NASA Astrophysics Data System (ADS)

Moeller, Ralf; Raguse, Marina; Leuko, Stefan; Berger, Thomas; Hellweg, Christine Elisabeth; Fujimori, Akira; Okayasu, Ryuichi; Horneck, Gerda

2017-02-01

In-depth knowledge regarding the biological effects of the radiation field in space is required for assessing the radiation risks in space. To obtain this knowledge, a set of different astrobiological model systems has been studied within the STARLIFE radiation campaign during six irradiation campaigns (2013-2015). The STARLIFE group is an international consortium with the aim to investigate the responses of different astrobiological model systems to the different types of ionizing radiation (X-rays, γ rays, heavy ions) representing major parts of the galactic cosmic radiation spectrum. Low- and high-energy charged particle radiation experiments have been conducted at the Heavy Ion Medical Accelerator in Chiba (HIMAC) facility at the National Institute of Radiological Sciences (NIRS) in Chiba, Japan. X-rays or γ rays were used as reference radiation at the German Aerospace Center (DLR, Cologne, Germany) or Beta-Gamma-Service GmbH (BGS, Wiehl, Germany) to derive the biological efficiency of different radiation qualities. All samples were exposed under identical conditions to the same dose and qualities of ionizing radiation (i) allowing a direct comparison between the tested specimens and (ii) providing information on the impact of the space radiation environment on currently used astrobiological model organisms.

Quick-scanning x-ray absorption spectroscopy system with a servo-motor-driven channel-cut monochromator with a temporal resolution of 10 ms.

PubMed

Nonaka, T; Dohmae, K; Araki, T; Hayashi, Y; Hirose, Y; Uruga, T; Yamazaki, H; Mochizuki, T; Tanida, H; Goto, S

2012-08-01

We have developed a quick-scanning x-ray absorption fine structure (QXAFS) system and installed it at the recently constructed synchrotron radiation beamline BL33XU at the SPring-8. Rapid acquisition of high-quality QXAFS data was realized by combining a servo-motor-driven Si channel-cut monochromator with a tapered undulator. Two tandemly aligned monochromators with channel-cut Si(111) and Si(220) crystals covered energy ranges of 4.0-28.2 keV and 6.6-46.0 keV, respectively. The system allows the users to adjust instantly the energy ranges of scans, the starting angles of oscillations, and the frequencies. The channel-cut crystals are cooled with liquid nitrogen to enable them to withstand the high heat load from the undulator radiation. Deformation of the reflecting planes is reduced by clamping each crystal with two cooling blocks. Performance tests at the Cu K-edge demonstrated sufficiently high data quality for x-ray absorption near-edge structure and extended x-ray absorption fine-structure analyses with temporal resolutions of up to 10 and 25 ms, respectively.

NASA X-Ray Observatory Completes Tests Under Harsh Simulated Space Conditions

NASA Astrophysics Data System (ADS)

1998-07-01

NASA's most powerful X-ray observatory has successfully completed a month-long series of tests in the extreme heat, cold, and airless conditions it will encounter in space during its five-year mission to shed new light on some of the darkest mysteries of the universe. The Advanced X-ray Astrophysics Facility was put through the rigorous testing as it was alternately heated and cooled in a special vacuum chamber at TRW Space and Electronics Group in Redondo Beach, Calif., NASA's prime contractor for the observatory. "Successful completion of thermal vacuum testing marks a significant step in readying the observatory for launch aboard the Space Shuttle in January," said Fred Wojtalik, manager of the Observatory Projects Office at NASA's Marshall Space Flight Center in Huntsville, Ala. "The observatory is a complex, highly sophisticated, precision instrument," explained Wojtalik. "We are pleased with the outcome of the testing, and are very proud of the tremendous team of NASA and contractor technicians, engineers and scientists that came together and worked hard to meet this challenging task." Testing began in May after the observatory was raised into the 60-foot thermal vacuum chamber at TRW. Testing was completed on June 20. During the tests the Advanced X-ray Astrophysics Facility was exposed to 232 degree heat and 195 degree below zero Fahrenheit cold. During four temperature cycles, all elements of the observatory - the spacecraft, telescope, and science instruments - were checked out. Computer commands directing the observatory to perform certain functions were sent from test consoles at TRW to all Advanced X-ray Astrophysics Facility components. A team of contractor and NASA engineers and scientists monitored and evaluated the results. Commands were also sent from, and test data monitored at, the Advanced X-ray Astrophysics Facility Operations Control Center in Cambridge, Mass., as part of the test series. The observatory will be managed and controlled from the Operations Control Center after launch. "As is usually the case, we identified a few issues to be resolved before launch," said Wojtalik. "Overall, however, the observatory performed exceptionally well." The observatory test team discovered a mechanical problem with one of the primary science instruments, the Imaging Spectrometer. A door protecting the instrument did not function when commanded by test controllers. "We do these tests to check and double check every aspect of satellite operation that could affect the ultimate success of the science mission," said Craig Staresinich, TRW Advanced X-ray Astrophysics Facility program manager. "Discovering a problem now is a success. Discovering a problem later, after launch, would be a failure." A team of NASA and contractor engineers are studying the mechanical problem and developing a plan to correct it. The instrument will be sent back to its builder, Lockheed-Martin Astronautics in Denver, Colo., where it will be repaired while the rest of the observatory continues other testing. This should still allow an on-time delivery of the observatory to NASA's Kennedy Space Center, Fla., in August, where it will be readied for launch in January. With a resolving power 10 times greater than previous X-ray telescopes, the new X-ray observatory will provide scientists with views of previously invisible X-ray sources, including black holes, exploding stars and interstellar gasses. The third of NASA's Great Observatories, it will join the Compton Gamma Ray Observatory and the Hubble Space Telescope in orbit. The Advanced X-ray Astrophysics Facility program is managed by the Marshall Center for the Office of Space Science, NASA Headquarters, Washington, D.C. TRW Space & Electronics Group is assembling the observatory and doing verification testing. The Advanced X-ray Astrophysics Facility Operations Control Center is operated by the Smithsonian Astrophysical Observatory. Using glass purchased from Schott Glaswerke, Mainz, Germany, the telescope's mirrors were built by Raytheon Optical Systems Inc., Danbury, Conn. The mirrors were coated by Optical Coating Laboratory, Inc., Santa Rosa, Calif., and assembled by EastmanKodak Co., Rochester, N.Y. The Advanced X-ray Astrophysics Facility Charge-Coupled Device Imaging Spectrometer was developed by Pennsylvania State University, University Park, Pa., and the Massachusetts Institute of Technology (MIT), Cambridge. One diffraction grating was developed by MIT, the other by the Space Research Organization Netherlands, Utrecht, Netherlands, in collaboration with the Max Planck Institute, Garching, Germany. The High Resolution Camera was built by the Smithsonian Astrophysical Observatory. Ball Aerospace & Technologies Corporation of Boulder, Colo., developed the aspect camera and the Science Instrument Module. Note to editors: Digital images to accompany this release are available via the World Wide Web at the following URL: http://chandra.harvard.edu/press/images.html

Online Tester for a Symbol Generator

NASA Technical Reports Server (NTRS)

Juday, D.; Mcconaugy, K.

1985-01-01

About 95 percent of faults detected. Programable instrument periodically checks for failures in system that generates alphanumerical and other symbol voltages for cathode-ray-tube displays. Symbol-generator tester compares gated test-point voltages with predetermined voltage limits while circuit under test performs commanded operation. A go/no-go indication given, depending on whether test voltage is or is not within its specification. Tester in plug-in modular form, temporarily wired to generator test points, or permanently wired to these points.

Design of the Readout Electronics for the BGO Calorimeter of DAMPE Mission

NASA Astrophysics Data System (ADS)

Feng, Changqing; Zhang, Deliang; Zhang, Junbin; Gao, Shanshan; Yang, Di; Zhang, Yunlong; Zhang, Zhiyong; Liu, Shubin; An, Qi

2015-12-01

The DAMPE (DArk Matter Particle Explorer) is a scientific satellite being developed in China, aimed at cosmic ray study, gamma ray astronomy, and searching for the clue of dark matter particles in the near future. The BGO (Bismuth Germanate Oxide) Calorimeter, which consists of 616 PMTs (photomultiplier tubes) and 1848 dynode signals, is a crucial part of the DAMPE payload for measuring the energy of cosmic ray particles, distinguishing interesting particles from background, and providing trigger information. An electronics system, which consists of 16 FEE (Front End Electronics) modules with a total power consumption of about 26 W, has been developed. Its main functions are based on the low power, 32-channel VA160 and VATA160 ASICs (Application Specific Integrated Circuits) for precisely measuring the charge of PMT signals and providing“hit”signals as well. To assure the long-term reliability in harsh space environment, a series of critical issues such as the radiation hardness, thermal design, components and board level quality control, etc., are taken into consideration. Test result showed that the system level ENC (equivalent noise charge) for each channel is about 10 fC in RMS (root mean square), and the timing uncertainty of the hit signals is about 300 ns, both of which satisfy the physics requirements of the detector. Experiments with 60Co radioactive source proved that 20 krad(Si) TID (Total Ionizing Dose) level is achieved, while the heavy ion beam and laser beam tests indicated that its SEL (Single Event Latch-up) and SEU (Single Event Upset) performance in orbit will be acceptable by taking some hardness measures. All the readout modules successfully passed the board-level screening, the sub-system level and finally the satellite system level environmental tests, and behave well in the beam test at CERN (European Organisation for Nuclear Research).

Focal Plane Detectors for the Advanced Gamma-Ray Imaging System (AGIS)

NASA Astrophysics Data System (ADS)

Wagner, Robert G.; AGIS Photodetector Group; Byrum, K.; Drake, G.; Falcone, A.; Funk, S.; Horan, D.; Mukherjee, R.; Tajima, H.; Williams, D.

2008-03-01

The Advanced Gamma-Ray Imaging System (AGIS) is a concept for the next generation observatory in ground-based very high energy gamma-ray astronomy. It is being designed to achieve a significant improvement in sensitivity compared to current Imaging Air Cherenkov Telescope (IACT) Arrays. One of the main requirements in order that AGIS fulfill this goal will be to achieve higher angular resolution than current IACTs. Simulations show that a substantial improvement in angular resolution may be achieved if the pixel size is reduced to less than 0.05 deg, i.e. two to three times smaller than the pixel size of current IACT cameras. With finer pixelation and the plan to deploy on the order of 100 telescopes in the AGIS array, the channel count will exceed 1,000,000 imaging pixels. High uniformity and long mean time-to-failure will be important aspects of a successful photodetector technology choice. Here we present alternatives being considered for AGIS, including both silicon photomultipliers (SiPMs) and multi-anode photomultipliers (MAPMTs). Results from laboratory testing of MAPMTs and SiPMs are presented along with results from the first incorporation of these devices in cameras on test bed Cherenkov telescopes.

Calibration of gamma-ray detectors using Gaussian photopeak fitting in the multichannel spectra with a LabVIEW-based digital system

NASA Astrophysics Data System (ADS)

Schlattauer, Leo; Parali, Levent; Pechousek, Jiri; Sabikoglu, Israfil; Celiktas, Cuneyt; Tektas, Gozde; Novak, Petr; Jancar, Ales; Prochazka, Vit

2017-09-01

This paper reports on the development of a gamma-ray spectroscopic system for the (i) recording and (ii) processing of spectra. The utilized data read-out unit consists of a PCI digital oscilloscope, personal computer and LabVIEW™ programming environment. A pulse-height spectra of various sources were recorded with two NaI(Tl) detectors and analyzed, demonstrating the proper usage of the detectors. A multichannel analyzer implements the Gaussian photopeak fitting. The presented method provides results which are in compliance to the ones taken from commercial spectroscopy systems. Each individual hardware or software unit can be further utilized in different spectrometric user-systems. An application of the developed system for research and teaching purposes regarding the design of digital spectrometric systems has been successfully tested at the laboratories of the Department of Experimental Physics.

Spectral X-ray Radiography for Safeguards at Nuclear Fuel Fabrication Facilities: A Feasibility Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilbert, Andrew J.; McDonald, Benjamin S.; Smith, Leon E.

The methods currently used by the International Atomic Energy Agency to account for nuclear materials at fuel fabrication facilities are time consuming and require in-field chemistry and operation by experts. Spectral X-ray radiography, along with advanced inverse algorithms, is an alternative inspection that could be completed noninvasively, without any in-field chemistry, with inspections of tens of seconds. The proposed inspection system and algorithms are presented here. The inverse algorithm uses total variation regularization and adaptive regularization parameter selection with the unbiased predictive risk estimator. Performance of the system is quantified with simulated X-ray inspection data and sensitivity of the outputmore » is tested against various inspection system instabilities. Material quantification from a fully-characterized inspection system is shown to be very accurate, with biases on nuclear material estimations of < 0.02%. It is shown that the results are sensitive to variations in the fuel powder sample density and detector pixel gain, which increase biases to 1%. Options to mitigate these inaccuracies are discussed.« less

Engineering aspects of the experiment and results of animal tests. [Apollo 17 Biological Cosmic Ray Experiment

NASA Technical Reports Server (NTRS)

Look, B. C.; Tremor, J. W.; Barrows, W. F.; Zabower, H. R.; Suri, K.; Park, E. G., Jr.; Durso, J. A.; Leon, H. A.; Haymaker, W.; Lindberg, R. G.

1975-01-01

A closed passive system independent of support from the spacecraft or its crew was developed to house five pocket mice for their flight on Apollo XVII. The reaction of potassium superoxide with carbon dioxide and water vapor to produce oxygen provided a habitable atmosphere within the experiment package. The performance of the system and the ability of the mice to survive the key preflight tests gave reasonable assurance that the mice would also withstand the Apollo flight.-

X-Ray Diffraction and Fluorescence Measurements for In Situ Planetary Instruments

NASA Astrophysics Data System (ADS)

Hansford, G.; Hill, K. S.; Talboys, D.; Vernon, D.; Ambrosi, R.; Bridges, J.; Hutchinson, I.; Marinangeli, L.

2011-12-01

The ESA/NASA ExoMars mission, due for launch in 2018, has a combined X-ray fluorescence/diffraction instrument, Mars-XRD, as part of the onboard analytical laboratory. The results of some XRF (X-ray fluorescence) and XRD (X-ray diffraction) tests using a laboratory chamber with representative performance are reported. A range of standard geological reference materials and analogues were used in these tests. The XRD instruments are core components of the forthcoming NASA Mars Science Laboratory (MSL) and ESA/NASA ExoMars missions and will provide the first demonstrations of the capabilities of combined XRD/XRF instrumentation in situ on an extraterrestrial planetary surface. The University of Leicester team is part of the Italy-UK collaboration that is responsible for building the ExoMars X-ray diffraction instrument, Mars-XRD [1,2]. Mars-XRD incorporates an Fe-55 radioisotope source and three fixed-position charge-coupled devices (CCDs) to simultaneously acquire an X-ray fluorescence spectrum and a diffraction pattern providing a measurement of both elemental and mineralogical composition. The CCDs cover an angular range of 2θ = 6° to 73° enabling the analysis of a wide range of geologically important minerals including phyllosilicates, feldspars, oxides, carbonates and evaporites. The identification of hydrous minerals may help identify past Martian hydrothermal systems capable of preserving traces of life. Here we present some initial findings from XRF and XRD tests carried out at the University of Leicester using an Fe-55 source and X-ray sensitive CCD. The XRF/XRD test system consists of a single CCD on a motorised arm, an Fe-55 X-ray source, a collimator and a sample table which approximately replicate the reflection geometry of the Mars-XRD instrument. It was used to test geological reference standard materials and Martian analogues. This work was funded by the Science and Technology Facilities Council, UK. References [1] Marinangeli, L., Hutchinson, I., Baliva, A., Stevoli, A., Ambrosi, R., Critani, F., Delhez, R., Scandelli, L., Holland, A., Nelms, N. & the Mars-XRD Team, Proceedings of the 38th Lunar and Planetary Science Conference, 12 - 16 March 2007, League City, Texas, USA. [2] L. Marinangeli, I. B. Hutchinson, A. Stevoli, G. Adami, R. Ambrosi, R. Amils, V. Assis Fernandes, A. Baliva, A. T. Basilevsky, G. Benedix, P. Bland, A. J. Böttger, J. Bridges, G. Caprarelli, G. Cressey, F. Critani, N. d'Alessandro, R. Delhez, C. Domeneghetti, D. Fernandez-Remolar, R. Filippone, A. M. Fioretti, J. M. Garcia Ruiz, M. Gilmore, G. M. Hansford, G. Iezzi, R. Ingley, M. Ivanov, G. Marseguerra, L. Moroz, C. Pelliciari, P. Petrinca, E. Piluso, L. Pompilio, J. Sykes, F. Westall and the MARS-XRD Team, EPSC-DPS Joint Meeting 2011, 3 - 7 October 2011, La Cité Internationale des Congrès Nantes Métropole, Nantes, France.

A mercuric iodide detector system for X-ray astronomy. II - Results from flight tests of a balloon borne instrument

NASA Technical Reports Server (NTRS)

Vallerga, J. V.; Vanderspek, R. K.; Ricker, G. R.

1983-01-01

To establish the expected sensitivity of a new hard X-ray telescope design, described by Ricker et al., an experiment was conducted to measure the background counting rate at balloon altitudes (40 km) of mercuric iodide, a room temperature solid state X-ray detector. The prototype detector consisted of two thin mercuric iodide (HgI2) detectors surrounded by a large bismuth germanate scintillator operated in anticoincidence. The bismuth germanate shield vetoed most of the background counting rate induced by atmospheric gamma-rays, neutrons and cosmic rays. A balloon-borne gondola containing a prototype detector assembly was designed, constructed and flown twice in the spring of 1982 from Palestine, TX. The second flight of this instrument established a differential background counting rate of 4.2 + or - 0.7 x 10 to the -5th counts/s sq cm keV over the energy range of 40-80 keV. This measurement was within 50 percent of the predicted value. The measured rate is about 5 times lower than previously achieved in shielded NaI/CsI or Ge systems operating in the same energy range.

The X-Ray Polarimeter Instrument on Board the Polarimeter for Relativistic Astrophysical X-Ray Sources (PRAXyS) Mission

NASA Technical Reports Server (NTRS)

Hill, J. E.; Black, J. K.; Jahoda, K.; Tamagawa, T.; Iwakiri, W.; Kitaguchi, T.; Kubota, M.; Kaaret, P.; Mccurdy, R.; Miles, D. M.;

Development of scanning x-ray fluorescence microscope with spatial resolution of 30 nm using Kirkpatrick-Baez mirror optics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsuyama, S.; Mimura, H.; Yumoto, H.

We developed a high-spatial-resolution scanning x-ray fluorescence microscope (SXFM) using Kirkpatrick-Baez mirrors. As a result of two-dimensional focusing tests at BL29XUL of SPring-8, the full width at half maximum of the focused beam was achieved to be 50x30 nm{sup 2} (VxH) under the best focusing conditions. The measured beam profiles were in good agreement with simulated results. Moreover, beam size was controllable within the wide range of 30-1400 nm by changing the virtual source size, although photon flux and size were in a trade-off relationship. To demonstrate SXFM performance, a fine test chart fabricated using focused ion beam system wasmore » observed to determine the best spatial resolution. The element distribution inside a logo mark of SPring-8 in the test chart, which has a minimum linewidth of approximately 50-60 nm, was visualized with a spatial resolution better than 30 nm using the smallest focused x-ray beam.« less

Increase in recombination rate in Arabidopsis thaliana plants sharing gaseous environment with X-ray and UVC-irradiated plants depends on production of radicals.

PubMed

Zemp, Franz J; Sidler, Corinne; Kovalchuk, Igor

2012-07-01

X-ray and UVC are the two physical agents that damage DNA directly, with both agents capable of inducing double-strand breaks. Some of our recent work has demonstrated that local exposure to UVC results in a systemic increase in recombination frequency, suggesting that information about exposure can be passed from damaged to non-damaged tissue. Indeed, we recently showed that plants sharing the same enclosed environment with UVC-irradiated plants exhibit similar increase in homologous recombination frequency as irradiated plants. Here, we further tested whether yet another DNA-damaging agent, X-ray, is capable of increasing recombination rate (RR) in neighboring plants grown in a Petri dish. To test this, we grew plants exposed to X-ray or UVC irradiation in an enclosed environment next to non-exposed plants. We found that both X-ray and UVC-irradiated plants and neighboring plants exhibited comparable increases in the levels of strand breaks and the RR. We further showed that pre-exposure of plants to radical scavenger DMSO substantially alleviates the radiation-induced increase in RR and prevents formation of bystander signal. Our results suggest that the increase in RR in bystander plants can also be triggered by X-ray and that radicals may play some role in initiation or maintenance of this signal.

Increase in recombination rate in Arabidopsis thaliana plants sharing gaseous environment with X-ray and UVC-irradiated plants depends on production of radicals

PubMed Central

Zemp, Franz J.; Sidler, Corinne; Kovalchuk, Igor

2012-01-01

X-ray and UVC are the two physical agents that damage DNA directly, with both agents capable of inducing double-strand breaks. Some of our recent work has demonstrated that local exposure to UVC results in a systemic increase in recombination frequency, suggesting that information about exposure can be passed from damaged to non-damaged tissue. Indeed, we recently showed that plants sharing the same enclosed environment with UVC-irradiated plants exhibit similar increase in homologous recombination frequency as irradiated plants. Here, we further tested whether yet another DNA-damaging agent, X-ray, is capable of increasing recombination rate (RR) in neighboring plants grown in a Petri dish. To test this, we grew plants exposed to X-ray or UVC irradiation in an enclosed environment next to non-exposed plants. We found that both X-ray and UVC-irradiated plants and neighboring plants exhibited comparable increases in the levels of strand breaks and the RR. We further showed that pre-exposure of plants to radical scavenger DMSO substantially alleviates the radiation-induced increase in RR and prevents formation of bystander signal. Our results suggest that the increase in RR in bystander plants can also be triggered by X-ray and that radicals may play some role in initiation or maintenance of this signal. PMID:22751301

An X-ray monitor for measurement of a titanium tritide target thickness

NASA Technical Reports Server (NTRS)

Alger, D. L.; Steinberg, R.

1972-01-01

An X-ray device capable of measuring titanium tritide film thickness from 0.1 to 30 micrometers has been built and tested. The monitor was designed for use in a rotating target system which used thick targets and incorporated a sputtering electrode to remove depleted layers from the target surface. The thickness measurement can be done in the presence of an intense background of bremsstrahlung and characteristic titanium X-radiation. A measurement can be accomplished in situ in two hours with reasonable accuracy.

X-ray-provoked non-Mendelian transgenerational oncodeterminants

NASA Technical Reports Server (NTRS)

Anders, A.; Fleming, C.; Schneider, H.; Groeger, H.; Schneider, E.; Kiefer, J.; Anders, F.

1994-01-01

Cancer is the most important risk of radiation exposure. There is a definite lack of suitable test systems, human epidemiological data are only available for certain radiation types, especially not for charged particles. We use the Xiphophorus model which is genetically well characterized. As a prelude to experiments with heavy ions we report here on results obtained with x-rays to establish the necessary baseline for future studies. Apart from this direct aim we hope to obtain also a better insight in the genetical determination of cancer formation.

Investigation of the possibility of gamma-ray diagnostic imaging of target compression at NIF

PubMed Central

Lemieux, Daniel A.; Baudet, Camille; Grim, Gary P.; Barber, H. Bradford; Miller, Brian W.; Fasje, David; Furenlid, Lars R.

2013-01-01

The National Ignition Facility at Lawrence Livermore National Laboratory is the world’s leading facility to study the physics of igniting plasmas. Plasmas of hot deuterium and tritium, undergo d(t,n)α reactions that produce a 14.1 MeV neutron and 3.5 MeV a particle, in the center of mass. As these neutrons pass through the materials surrounding the hot core, they may undergo subsequent (n,x) reactions. For example, 12C(n,n’γ)12C reactions occur in remnant debris from the polymer ablator resulting in a significant fluence of 4.44 MeV gamma-rays. Imaging of these gammas will enable the determination of the volumetric size and symmetry of the ablation; large size and high asymmetry is expected to correlate with poor compression and lower fusion yield. Results from a gamma-ray imaging system are expected to be complimentary to a neutron imaging diagnostic system already in place at the NIF. This paper describes initial efforts to design a gamma-ray imaging system for the NIF using the existing neutron imaging system as a baseline for study. Due to the cross-section and expected range of ablator areal densities, the gamma flux should be approximately 10−3 of the neutron flux. For this reason, care must be taken to maximize the efficiency of the gamma-ray imaging system because it will be gamma starved. As with the neutron imager, use of pinholes and/or coded apertures are anticipated. Along with aperture and detector design, the selection of an appropriate scintillator is discussed. The volume of energy deposition of the interacting 4.44 MeV gamma-rays is a critical parameter limiting the imaging system spatial resolution. The volume of energy deposition is simulated with GEANT4, and plans to measure the volume of energy deposition experimentally are described. Results of tests on a pixellated LYSO scintillator are also presented. PMID:23420688

Investigation of the possibility of gamma-ray diagnostic imaging of target compression at NIF

NASA Astrophysics Data System (ADS)

Lemieux, Daniel A.; Baudet, Camille; Grim, Gary P.; Barber, H. Bradford; Miller, Brian W.; Fasje, David; Furenlid, Lars R.

2011-09-01

The National Ignition Facility at Lawrence Livermore National Laboratory is the world's leading facility to study the physics of igniting plasmas. Plasmas of hot deuterium and tritium, undergo d(t,n)α reactions that produce a 14.1 MeV neutron and 3.5 MeV a particle, in the center of mass. As these neutrons pass through the materials surrounding the hot core, they may undergo subsequent (n,x) reactions. For example, 12C(n,n'γ)12C reactions occur in remnant debris from the polymer ablator resulting in a significant fluence of 4.44 MeV gamma-rays. Imaging of these gammas will enable the determination of the volumetric size and symmetry of the ablation; large size and high asymmetry is expected to correlate with poor compression and lower fusion yield. Results from a gamma-ray imaging system are expected to be complimentary to a neutron imaging diagnostic system already in place at the NIF. This paper describes initial efforts to design a gamma-ray imaging system for the NIF using the existing neutron imaging system as a baseline for study. Due to the cross-section and expected range of ablator areal densities, the gamma flux should be approximately 10-3 of the neutron flux. For this reason, care must be taken to maximize the efficiency of the gamma-ray imaging system because it will be gamma starved. As with the neutron imager, use of pinholes and/or coded apertures are anticipated. Along with aperture and detector design, the selection of an appropriate scintillator is discussed. The volume of energy deposition of the interacting 4.44 MeV gamma-rays is a critical parameter limiting the imaging system spatial resolution. The volume of energy deposition is simulated with GEANT4, and plans to measure the volume of energy deposition experimentally are described. Results of tests on a pixellated LYSO scintillator are also presented.

Investigation of the possibility of gamma-ray diagnostic imaging of target compression at NIF.

PubMed

Lemieux, Daniel A; Baudet, Camille; Grim, Gary P; Barber, H Bradford; Miller, Brian W; Fasje, David; Furenlid, Lars R

2011-09-23

The National Ignition Facility at Lawrence Livermore National Laboratory is the world's leading facility to study the physics of igniting plasmas. Plasmas of hot deuterium and tritium, undergo d(t,n)α reactions that produce a 14.1 MeV neutron and 3.5 MeV a particle, in the center of mass. As these neutrons pass through the materials surrounding the hot core, they may undergo subsequent (n,x) reactions. For example, (12)C(n,n'γ)(12)C reactions occur in remnant debris from the polymer ablator resulting in a significant fluence of 4.44 MeV gamma-rays. Imaging of these gammas will enable the determination of the volumetric size and symmetry of the ablation; large size and high asymmetry is expected to correlate with poor compression and lower fusion yield. Results from a gamma-ray imaging system are expected to be complimentary to a neutron imaging diagnostic system already in place at the NIF. This paper describes initial efforts to design a gamma-ray imaging system for the NIF using the existing neutron imaging system as a baseline for study. Due to the cross-section and expected range of ablator areal densities, the gamma flux should be approximately 10(-3) of the neutron flux. For this reason, care must be taken to maximize the efficiency of the gamma-ray imaging system because it will be gamma starved. As with the neutron imager, use of pinholes and/or coded apertures are anticipated. Along with aperture and detector design, the selection of an appropriate scintillator is discussed. The volume of energy deposition of the interacting 4.44 MeV gamma-rays is a critical parameter limiting the imaging system spatial resolution. The volume of energy deposition is simulated with GEANT4, and plans to measure the volume of energy deposition experimentally are described. Results of tests on a pixellated LYSO scintillator are also presented.

Recent Advances in X-ray Cone-beam Computed Laminography.

PubMed

O'Brien, Neil S; Boardman, Richard P; Sinclair, Ian; Blumensath, Thomas

2016-10-06

X-ray computed tomography is an established volume imaging technique used routinely in medical diagnosis, industrial non-destructive testing, and a wide range of scientific fields. Traditionally, computed tomography uses scanning geometries with a single axis of rotation together with reconstruction algorithms specifically designed for this setup. Recently there has however been increasing interest in more complex scanning geometries. These include so called X-ray computed laminography systems capable of imaging specimens with large lateral dimensions or large aspect ratios, neither of which are well suited to conventional CT scanning procedures. Developments throughout this field have thus been rapid, including the introduction of novel system trajectories, the application and refinement of various reconstruction methods, and the use of recently developed computational hardware and software techniques to accelerate reconstruction times. Here we examine the advances made in the last several years and consider their impact on the state of the art.

New software to model energy dispersive X-ray diffraction in polycrystalline materials

NASA Astrophysics Data System (ADS)

Ghammraoui, B.; Tabary, J.; Pouget, S.; Paulus, C.; Moulin, V.; Verger, L.; Duvauchelle, Ph.

2012-02-01

Detection of illicit materials, such as explosives or drugs, within mixed samples is a major issue, both for general security and as part of forensic analyses. In this paper, we describe a new code simulating energy dispersive X-ray diffraction patterns in polycrystalline materials. This program, SinFullscat, models diffraction of any object in any diffractometer system taking all physical phenomena, including amorphous background, into account. Many system parameters can be tuned: geometry, collimators (slit and cylindrical), sample properties, X-ray source and detector energy resolution. Good agreement between simulations and experimental data was obtained. Simulations using explosive materials indicated that parameters such as the diffraction angle or the energy resolution of the detector have a significant impact on the diffraction signature of the material inspected. This software will be a convenient tool to test many diffractometer configurations, providing information on the one that best restores the spectral diffraction signature of the materials of interest.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dufresne, Eric M.; Dunford, Robert W.; Kanter, Elliot P.

The performance of a cooled Be compound refractive lens (CRL) has been tested at the Advanced Photon Source (APS) to enable vertical focusing of the pink beam and permit the X-ray beam to spatially overlap with an 80 µm-high low-density plasma that simulates astrophysical environments. Focusing the fundamental harmonics of an insertion device white beam increases the APS power density; here, a power density as high as 500 W mm –2 was calculated. A CRL is chromatic so it does not efficiently focus X-rays whose energies are above the fundamental. Only the fundamental of the undulator focuses at the experiment.more » A two-chopper system reduces the power density on the imaging system and lens by four orders of magnitude, enabling imaging of the focal plane without any X-ray filter. As a result, a method to measure such high power density as well as the performance of the lens in focusing the pink beam is reported.« less

Stacked, Filtered Multi-Channel X-Ray Diode Array

DOE Office of Scientific and Technical Information (OSTI.GOV)

MacNeil, Lawrence P.; Dutra, Eric C.; Raphaelian, Mark

2015-08-01

This system meets the need for a low-cost, robust X-ray diode array to use for experiments in hostile environments on multiple platforms, and for experiments utilizing forces that may destroy the diode(s). Since these uses require a small size with a minimal single line-of-sight, a parallel array often cannot be used. So a stacked, filtered multi-channel X-ray diode array was developed that was called the MiniXRD. The design was modeled, built, and tested at National Security Technologies, LLC (NSTec) Livermore Operations (LO) to determine fundamental characteristics. Then, several different systems were fielded as ancillary “ridealong” diagnostics at several national facilitiesmore » to allow us to iteratively improve the design and usability. Presented here are design considerations and experimental results. This filtered diode array is currently at Technical Readiness Level (TRL) 6.« less

Low Noise Double-Sided Silicon Strip Detector for Multiple-Compton Gamma-ray Telescope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tajima, Hiroyasu

2002-12-03

A Semiconductor Multiple-Compton Telescope (SMCT) is being developed to explore the gamma-ray universe in an energy band 0.1-20 MeV, which is not well covered by the present or near-future gamma-ray telescopes. The key feature of the SMCT is the high energy resolution that is crucial for high angular resolution and high background rejection capability. We have developed prototype modules for a low noise Double-sided Silicon Strip Detector (DSSD) system which is an essential element of the SMCT. The geometry of the DSSD is optimized to achieve the lowest noise possible. A new front-end VLSI device optimized for low noise operationmore » is also developed. We report on the design and test results of the prototype system. We have reached an energy resolution of 1.3 keV (FWHM) for 60 keV and 122 keV at 0 C.« less

Photodetectors for the Advanced Gamma-ray Imaging System (AGIS)

NASA Astrophysics Data System (ADS)

Wagner, Robert G.; Advanced Gamma-ray Imaging System AGIS Collaboration

2010-03-01

The Advanced Gamma-Ray Imaging System (AGIS) is a concept for the next generation very high energy gamma-ray observatory. Design goals include an order of magnitude better sensitivity, better angular resolution, and a lower energy threshold than existing Cherenkov telescopes. Each telescope is equipped with a camera that detects and records the Cherenkov-light flashes from air showers. The camera is comprised of a pixelated focal plane of blue sensitive and fast (nanosecond) photon detectors that detect the photon signal and convert it into an electrical one. Given the scale of AGIS, the camera must be reliable and cost effective. The Schwarzschild-Couder optical design yields a smaller plate scale than present-day Cherenkov telescopes, enabling the use of more compact, multi-pixel devices, including multianode photomultipliers or Geiger avalanche photodiodes. We present the conceptual design of the focal plane for the camera and results from testing candidate! focal plane sensors.

The Bursting Pulsar GRO J1744-28: the slowest transitional pulsar?

NASA Astrophysics Data System (ADS)

Court, J. M. C.; Altamirano, D.; Sanna, A.

2018-06-01

GRO J1744-28 (the Bursting Pulsar) is a neutron star low-mass X-ray binary which shows highly structured X-ray variability near the end of its X-ray outbursts. In this letter we show that this variability is analogous to that seen in Transitional Millisecond Pulsars such as PSR J1023+0038: `missing link' systems consisting of a pulsar nearing the end of its recycling phase. As such, we show that the Bursting Pulsar may also be associated with this class of objects. We discuss the implications of this scenario; in particular, we discuss the fact that the Bursting Pulsar has a significantly higher spin period and magnetic field than any other known transitional pulsar. If the Bursting Pulsar is indeed transitional, then this source opens a new window of opportunity to test our understanding of these systems in an entirely unexplored physical regime.

AXAF-1 High Resolution Assembly Image Model and Comparison with X-Ray Ground Test Image

NASA Technical Reports Server (NTRS)

Zissa, David E.

1999-01-01

The x-ray ground test of the AXAF-I High Resolution Mirror Assembly was completed in 1997 at the X-ray Calibration Facility at Marshall Space Flight Center. Mirror surface measurements by HDOS, alignment results from Kodak, and predicted gravity distortion in the horizontal test configuration are being used to model the x-ray test image. The Marshall Space Flight Center (MSFC) image modeling serves as a cross check with Smithsonian Astrophysical observatory modeling. The MSFC image prediction software has evolved from the MSFC model of the x-ray test of the largest AXAF-I mirror pair in 1991. The MSFC image modeling software development is being assisted by the University of Alabama in Huntsville. The modeling process, modeling software, and image prediction will be discussed. The image prediction will be compared with the x-ray test results.

AGATE: A High Energy Gamma-Ray Telescope Using Drift Chambers

NASA Astrophysics Data System (ADS)

Mukherjee, R.; Dingus, B. L.; Esposito, J. A.; Bertsch, D. L.; Cuddapah, R.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Thompson, D. J.

1996-01-01

The exciting results from the highly successful Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray Observatory (CGRO) has contributed significantly to increasing our understanding of high energy gamma-ray astronomy. A follow-on mission to EGRET is needed to continue these scientific advances as well as to address the several new scientific questions raised by EGRET. Here we describe the work being done on the development of the Advanced Gamma-Ray Astronomy Telescope Experiment (AGATE), visualized as the successor to EGRET. In order to achieve the scientific goals, AGATE will have higher sensitivity than EGRET in the energy range 30 MeV to 30 GeV, larger effective area, better angular resolution, and an extended low and high energy range. In its design, AGATE will follow the tradition of the earlier gamma-ray telescopes, SAS-2, COS B, and EGRET, and will have the same four basic components of an anticoincidence system, directional coincidence system, track imaging, and energy measurement systems. However, due to its much larger size, AGATE will use drift chambers as its track imaging system rather than the spark chambers used by EGRET. Drift chambers are an obvious choice as they have less deadtime per event, better spatial resolution, and are relatively easy and inexpensive to build. Drift chambers have low power requirements, so that many layers of drift chambers can be included. To test the feasibility of using drift chambers, we have constructed a prototype instrument consisting of a stack of sixteen 1/2m × 1/2m drift chambers and have measured the spatial resolution using atmospheric muons. The results on the drift chamber performance in the laboratory are presented here.

MicroCT with energy-resolved photon-counting detectors

PubMed Central

Wang, X; Meier, D; Mikkelsen, S; Maehlum, G E; Wagenaar, D J; Tsui, BMW; Patt, B E; Frey, E C

2011-01-01

The goal of this paper was to investigate the benefits that could be realistically achieved on a microCT imaging system with an energy-resolved photon-counting x-ray detector. To this end, we built and evaluated a prototype microCT system based on such a detector. The detector is based on cadmium telluride (CdTe) radiation sensors and application-specific integrated circuit (ASIC) readouts. Each detector pixel can simultaneously count x-ray photons above six energy thresholds, providing the capability for energy-selective x-ray imaging. We tested the spectroscopic performance of the system using polychromatic x-ray radiation and various filtering materials with Kabsorption edges. Tomographic images were then acquired of a cylindrical PMMA phantom containing holes filled with various materials. Results were also compared with those acquired using an intensity-integrating x-ray detector and single-energy (i.e. non-energy-selective) CT. This paper describes the functionality and performance of the system, and presents preliminary spectroscopic and tomographic results. The spectroscopic experiments showed that the energy-resolved photon-counting detector was capable of measuring energy spectra from polychromatic sources like a standard x-ray tube, and resolving absorption edges present in the energy range used for imaging. However, the spectral quality was degraded by spectral distortions resulting from degrading factors, including finite energy resolution and charge sharing. We developed a simple charge-sharing model to reproduce these distortions. The tomographic experiments showed that the availability of multiple energy thresholds in the photon-counting detector allowed us to simultaneously measure target-to-background contrasts in different energy ranges. Compared with single-energy CT with an integrating detector, this feature was especially useful to improve differentiation of materials with different attenuation coefficient energy dependences. PMID:21464527

MicroCT with energy-resolved photon-counting detectors.

PubMed

Wang, X; Meier, D; Mikkelsen, S; Maehlum, G E; Wagenaar, D J; Tsui, B M W; Patt, B E; Frey, E C

2011-05-07

The goal of this paper was to investigate the benefits that could be realistically achieved on a microCT imaging system with an energy-resolved photon-counting x-ray detector. To this end, we built and evaluated a prototype microCT system based on such a detector. The detector is based on cadmium telluride (CdTe) radiation sensors and application-specific integrated circuit (ASIC) readouts. Each detector pixel can simultaneously count x-ray photons above six energy thresholds, providing the capability for energy-selective x-ray imaging. We tested the spectroscopic performance of the system using polychromatic x-ray radiation and various filtering materials with K-absorption edges. Tomographic images were then acquired of a cylindrical PMMA phantom containing holes filled with various materials. Results were also compared with those acquired using an intensity-integrating x-ray detector and single-energy (i.e. non-energy-selective) CT. This paper describes the functionality and performance of the system, and presents preliminary spectroscopic and tomographic results. The spectroscopic experiments showed that the energy-resolved photon-counting detector was capable of measuring energy spectra from polychromatic sources like a standard x-ray tube, and resolving absorption edges present in the energy range used for imaging. However, the spectral quality was degraded by spectral distortions resulting from degrading factors, including finite energy resolution and charge sharing. We developed a simple charge-sharing model to reproduce these distortions. The tomographic experiments showed that the availability of multiple energy thresholds in the photon-counting detector allowed us to simultaneously measure target-to-background contrasts in different energy ranges. Compared with single-energy CT with an integrating detector, this feature was especially useful to improve differentiation of materials with different attenuation coefficient energy dependences.

Coded-aperture Compton camera for gamma-ray imaging

NASA Astrophysics Data System (ADS)

Farber, Aaron M.

This dissertation describes the development of a novel gamma-ray imaging system concept and presents results from Monte Carlo simulations of the new design. Current designs for large field-of-view gamma cameras suitable for homeland security applications implement either a coded aperture or a Compton scattering geometry to image a gamma-ray source. Both of these systems require large, expensive position-sensitive detectors in order to work effectively. By combining characteristics of both of these systems, a new design can be implemented that does not require such expensive detectors and that can be scaled down to a portable size. This new system has significant promise in homeland security, astronomy, botany and other fields, while future iterations may prove useful in medical imaging, other biological sciences and other areas, such as non-destructive testing. A proof-of-principle study of the new gamma-ray imaging system has been performed by Monte Carlo simulation. Various reconstruction methods have been explored and compared. General-Purpose Graphics-Processor-Unit (GPGPU) computation has also been incorporated. The resulting code is a primary design tool for exploring variables such as detector spacing, material selection and thickness and pixel geometry. The advancement of the system from a simple 1-dimensional simulation to a full 3-dimensional model is described. Methods of image reconstruction are discussed and results of simulations consisting of both a 4 x 4 and a 16 x 16 object space mesh have been presented. A discussion of the limitations and potential areas of further study is also presented.

Explosive simulants for testing explosive detection systems

DOEpatents

Kury, John W.; Anderson, Brian L.

1999-09-28

Explosives simulants that include non-explosive components are disclosed that facilitate testing of equipment designed to remotely detect explosives. The simulants are non-explosive, non-hazardous materials that can be safely handled without any significant precautions. The simulants imitate real explosives in terms of mass density, effective atomic number, x-ray transmission properties, and physical form, including moldable plastics and emulsions/gels.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1977-06-01

This photograph is of the High Energy Astronomy Observatory (HEAO)-2 telescope being checked by engineers in the X-Ray Calibration Facility at the Marshall Space Flight Center (MSFC). The MSFC was heavily engaged in the technical and scientific aspects, testing and calibration, of the HEAO-2 telescope. The HEAO-2 was the first imaging and largest x-ray telescope built to date. The X-Ray Calibration Facility was built in 1976 for testing MSFC's HEAO-2. The facility is the world's largest, most advanced laboratory for simulating x-ray emissions from distant celestial objects. It produced a space-like environment in which components related to x-ray telescope imaging are tested and the quality of their performance in space is predicted. The original facility contained a 1,000-foot long by 3-foot diameter vacuum tube (for the x-ray path) cornecting an x-ray generator and an instrument test chamber. Recently, the facility was upgraded to evaluate the optical elements of NASA's Hubble Space Telescope, Chandra X-Ray Observatory and Compton Gamma-Ray Observatory.

X-ray beam method for displacement measurement in hostile environments

NASA Technical Reports Server (NTRS)

Jordan, Eric H.; Pease, D. M.; Canistraro, H.; Brew, Dale

1989-01-01

A new method of extensometry using an X-ray beam was devised, and the results of current testing reveal it to be highly feasible. This technique has been shown to provide a non-contacting system that is immune to problems associated with density variations in gaseous environments, that plague currently available optical methods. This advantage is a result of the non-refracting penetrating nature of X-rays. The method is based on X-ray-induced X-ray fluorescence of targets, which subsequently serve as fudicial markers. Some target materials have melting points over 1600 degrees C which will facilitate measurement at extremely high temperatures. A highly focused intense X-ray beam, which is produced using a Johansen 'bent crystal', is then scanned across the target, which responds by fluorescing X-rays when stimulated by the incident beam. This secondary radiation is monitored using a detector. By carefully measuring beam orientation, change in target edge position can be determined. Many variations on this basic theme are now possible such as two targets demarcating a gage length, or a beam shadowing method using opaque targets.

A small-angle x-ray scattering system with a vertical layout

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zhen; Chen, Xiaowei; Meng, Lingpu

A small-angle x-ray scattering (SAXS) system with a vertical layout (V-SAXS) has been designed and constructed for in situ detection on nanostructures, which is well suitable for in situ study on self-assembly of nanoparticles at liquid interface and polymer processing. A steel-tower frame on a reinforced basement is built as the supporting skeleton for scattering beam path and detector platform, ensuring the system a high working stability and a high operating accuracy. A micro-focus x-ray source combining parabolic three-dimensional multi-layer mirror and scatteringless collimation system provides a highly parallel beam, which allows us to detect the very small angle range.more » With a sample-to-detector distance of 7 m, the largest measurable length scale is 420 nm in real space. With a large sample zone, it is possible to install different experimental setups such as film stretching machine, which makes the system perfect to follow the microstructures evolution of materials during processing. The capability of the V-SAXS on in situ study is tested with a drying experiment of a free latex droplet, which confirms our initial design.« less

Pulsed Laser System to Simulate Effects of Cosmic Rays in Semiconductor Devices

NASA Technical Reports Server (NTRS)

Aveline, David C.; Adell, Philippe C.; Allen, Gregory R.; Guertin, Steven M.; McClure, Steven S.

2011-01-01

Spaceflight system electronic devices must survive a wide range of radiation environments with various particle types including energetic protons, electrons, gamma rays, x-rays, and heavy ions. High-energy charged particles such as heavy ions can pass straight through a semiconductor material and interact with a charge-sensitive region, generating a significant amount of charge (electron-hole pairs) along their tracks. These excess charges can damage the device, and the response can range from temporary perturbations to permanent changes in the state or performance. These phenomena are called single event effects (SEE). Before application in flight systems, electronic parts need to be qualified and tested for performance and radiation sensitivity. Typically, their susceptibility to SEE is tested by exposure to an ion beam from a particle accelerator. At such facilities, the device under test (DUT) is irradiated with large beams so there is no fine resolution to investigate particular regions of sensitivity on the parts. While it is the most reliable approach for radiation qualification, these evaluations are time consuming and costly. There is always a need for new cost-efficient strategies to complement accelerator testing: pulsed lasers provide such a solution. Pulsed laser light can be utilized to simulate heavy ion effects with the advantage of being able to localize the sensitive region of an integrated circuit. Generally, a focused laser beam of approximately picosecond pulse duration is used to generate carrier density in the semiconductor device. During irradiation, the laser pulse is absorbed by the electronic medium with a wavelength selected accordingly by the user, and the laser energy can ionize and simulate SEE as would occur in space. With a tightly focused near infrared (NIR) laser beam, the beam waist of about a micrometer can be achieved, and additional scanning techniques are able to yield submicron resolution. This feature allows mapping of all of the sensitive regions of the studied device with fine resolution, unlike heavy ion experiments. The problematic regions can be precisely identified, and it provides a considerable amount of information about the circuit. In addition, the system allows flexibility for testing the device in different configurations in situ.

X-ray induced formation of γ-H2AX foci after full-field digital mammography and digital breast-tomosynthesis.

PubMed

Schwab, Siegfried A; Brand, Michael; Schlude, Ina-Kristin; Wuest, Wolfgang; Meier-Meitinger, Martina; Distel, Luitpold; Schulz-Wendtland, Ruediger; Uder, Michael; Kuefner, Michael A

2013-01-01

To determine in-vivo formation of x-ray induced γ-H2AX foci in systemic blood lymphocytes of patients undergoing full-field digital mammography (FFDM) and to estimate foci after FFDM and digital breast-tomosynthesis (DBT) using a biological phantom model. The study complies with the Declaration of Helsinki and was performed following approval by the ethic committee of the University of Erlangen-Nuremberg. Written informed consent was obtained from every patient. For in-vivo tests, systemic blood lymphocytes were obtained from 20 patients before and after FFDM. In order to compare in-vivo post-exposure with pre-exposure foci levels, the Wilcoxon matched pairs test was used. For in-vitro experiments, isolated blood lymphocytes from healthy volunteers were irradiated at skin and glandular level of a porcine breast using FFDM and DBT. Cells were stained against the phosphorylated histone variant γ-H2AX, and foci representing distinct DNA damages were quantified. Median in-vivo foci level/cell was 0.086 (range 0.067-0.116) before and 0.094 (0.076-0.126) after FFDM (p = 0.0004). In the in-vitro model, the median x-ray induced foci level/cell after FFDM was 0.120 (range 0.086-0.140) at skin level and 0.035 (range 0.030-0.050) at glandular level. After DBT, the median x-ray induced foci level/cell was 0.061 (range 0.040-0.081) at skin level and 0.015 (range 0.006-0.020) at glandular level. In patients, mammography induces a slight but significant increase of γ-H2AX foci in systemic blood lymphocytes. The introduced biological phantom model is suitable for the estimation of x-ray induced DNA damages in breast tissue in different breast imaging techniques.

The agile alert system for gamma-ray transients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bulgarelli, A.; Trifoglio, M.; Gianotti, F.

2014-01-20

In recent years, a new generation of space missions has offered great opportunities for discovery in high-energy astrophysics. In this article we focus on the scientific operations of the Gamma-Ray Imaging Detector (GRID) on board the AGILE space mission. AGILE-GRID, sensitive in the energy range of 30 MeV-30 GeV, has detected many γ-ray transients of both galactic and extragalactic origin. This work presents the AGILE innovative approach to fast γ-ray transient detection, which is a challenging task and a crucial part of the AGILE scientific program. The goals are to describe (1) the AGILE Gamma-Ray Alert System, (2) a newmore » algorithm for blind search identification of transients within a short processing time, (3) the AGILE procedure for γ-ray transient alert management, and (4) the likelihood of ratio tests that are necessary to evaluate the post-trial statistical significance of the results. Special algorithms and an optimized sequence of tasks are necessary to reach our goal. Data are automatically analyzed at every orbital downlink by an alert pipeline operating on different timescales. As proper flux thresholds are exceeded, alerts are automatically generated and sent as SMS messages to cellular telephones, via e-mail, and via push notifications from an application for smartphones and tablets. These alerts are crosschecked with the results of two pipelines, and a manual analysis is performed. Being a small scientific-class mission, AGILE is characterized by optimization of both scientific analysis and ground-segment resources. The system is capable of generating alerts within two to three hours of a data downlink, an unprecedented reaction time in γ-ray astrophysics.« less

The AGILE Alert System for Gamma-Ray Transients

NASA Astrophysics Data System (ADS)

Bulgarelli, A.; Trifoglio, M.; Gianotti, F.; Tavani, M.; Parmiggiani, N.; Fioretti, V.; Chen, A. W.; Vercellone, S.; Pittori, C.; Verrecchia, F.; Lucarelli, F.; Santolamazza, P.; Fanari, G.; Giommi, P.; Beneventano, D.; Argan, A.; Trois, A.; Scalise, E.; Longo, F.; Pellizzoni, A.; Pucella, G.; Colafrancesco, S.; Conforti, V.; Tempesta, P.; Cerone, M.; Sabatini, P.; Annoni, G.; Valentini, G.; Salotti, L.

2014-01-01

In recent years, a new generation of space missions has offered great opportunities for discovery in high-energy astrophysics. In this article we focus on the scientific operations of the Gamma-Ray Imaging Detector (GRID) on board the AGILE space mission. AGILE-GRID, sensitive in the energy range of 30 MeV-30 GeV, has detected many γ-ray transients of both galactic and extragalactic origin. This work presents the AGILE innovative approach to fast γ-ray transient detection, which is a challenging task and a crucial part of the AGILE scientific program. The goals are to describe (1) the AGILE Gamma-Ray Alert System, (2) a new algorithm for blind search identification of transients within a short processing time, (3) the AGILE procedure for γ-ray transient alert management, and (4) the likelihood of ratio tests that are necessary to evaluate the post-trial statistical significance of the results. Special algorithms and an optimized sequence of tasks are necessary to reach our goal. Data are automatically analyzed at every orbital downlink by an alert pipeline operating on different timescales. As proper flux thresholds are exceeded, alerts are automatically generated and sent as SMS messages to cellular telephones, via e-mail, and via push notifications from an application for smartphones and tablets. These alerts are crosschecked with the results of two pipelines, and a manual analysis is performed. Being a small scientific-class mission, AGILE is characterized by optimization of both scientific analysis and ground-segment resources. The system is capable of generating alerts within two to three hours of a data downlink, an unprecedented reaction time in γ-ray astrophysics.

21 CFR Appendix B to Subpart B of... - Scope of Product Coverage

Code of Federal Regulations, 2010 CFR

2010-04-01

... Transducer ITX—Transducer, Ultrasonic, Diagnostic Diagnostic X-Ray Imaging Devices (except mammographic x-ray systems): RA 892.1600 Angiographic X-Ray System IZI—System, X-Ray, Angiographic RA 892.1650 Image-Intensified Fluoroscopic X-Ray System MQB—Solid State X-Ray Imager (Flat Panel/Digital Imager) JAA—System, X...

21 CFR Appendix B to Subpart B of... - Scope of Product Coverage

Code of Federal Regulations, 2011 CFR

2011-04-01

... Transducer ITX—Transducer, Ultrasonic, Diagnostic Diagnostic X-Ray Imaging Devices (except mammographic x-ray systems): RA 892.1600 Angiographic X-Ray System IZI—System, X-Ray, Angiographic RA 892.1650 Image-Intensified Fluoroscopic X-Ray System MQB—Solid State X-Ray Imager (Flat Panel/Digital Imager) JAA—System, X...

Computer output microfilm (FR80) systems software documentation, volume 2

NASA Technical Reports Server (NTRS)

1975-01-01

The system consists of a series of programs which convert digital data from magnetic tapes into alpha-numeric characters, graphic plots, and imagery that is recorded on the face of a cathode ray tube. A special camera photographs the face of the tube on microfilm for subsequent display on a film reader. The applicable documents which apply to this system are delineated. The functional relationship between the system software, the standard insert routines, and the applications programs is described; all the applications programs are described in detail. Instructions for locating those documents are presented along with test preparations sheets for all baseline and/or program modification acceptance tests.

Development and Testing of the AMEGO Silicon Tracker System

NASA Astrophysics Data System (ADS)

Griffin, Sean; Amego Team

2018-01-01

The All-sky Medium Energy Gamma-ray Observatory (AMEGO) is a probe-class mission in consideration for the 2020 decadal review designed to operate at energies from ˜ 200 keV to > 10 GeV. Operating a detector in this energy regime is challenging due to the crossover in the interaction cross-section for Compton scattering and pair production. AMEGO is made of four major subsystems: a plastic anticoincidence detector for rejecting cosmic-ray events, a silicon tracker for measuring the energies of Compton scattered electrons and pair-production products, a CZT calorimeter for measuring the energy and location of Compton scattered photons, and a CsI calorimeter for measuring the energy of the pair-production products at high energies. The tracker comprises layers of dual-sided silicon strip detectors which provide energy and localization information for Compton scattering and pair-production events. A prototype tracker system is under development at GSFC; in this contribution we provide details on the verification, packaging, and testing of the prototype tracker, as well as present plans for the development of the front-end electronics, beam tests, and a balloon flight.

The anticoincidence system of the PAMELA satellite experiment: Design of the data acquisition system and performance studies

NASA Astrophysics Data System (ADS)

Lunquist, Johan

PAMELA is a satellite-borne cosmic ray experiment. Its primary scientific objective is to study the antiproton and positron components of the cosmic radiation. This will be done with unprecedented statistics over a wide energy range (~10MeV to ~100GeV). The PAMELA experiment consists of a permanent magnetic spectrometer, an electromagnetic calorimeter, a Time-of-Fight system, a neutron detector and a shower tail catcher. An anticoincidence (AC) system surrounds the spectrometer to detect particles which do not pass cleanly through the acceptance of the spectrometer. PAMELA will be mounted on a Russian Earth-observation satellite, and the launch is scheduled for 2006. The anticoincidence system for PAMELA has been developed by KTH, and consists of plastic scintillator detectors with photomultiplier tube read-out. Extensive testing has been performed during the development phase. Results are presented for environmental tests, tests with cosmic-rays and particle beams. The design of the digital part of the AC electronics has been realised on an FPGA (Field Programmable Gate Array) and a DSP (Digital Signal Processor). It records signals from the 16 AC photomultipliers and from various sensors for over-current and temperature. It also provides functionality for setting the photomultiplier discrimination thresholds, system testing, issuing alarms and communication with the PAMELA main data acquisition system. The design philosophy and functionality needs to be reliable and suitable for use in a space environment. To evaluate the performance of the AC detectors, a test utilizing cosmic-rays has been performed. The primary aim of the test was to calibrate the individual channels to gain knowledge of suitable discriminator levels for flight. A secondary aim was to estimate the AC detector efficiency. A lower limit of (99.89±0.04)% was obtained. An in-orbit simulation study was performed using protons to estimate trigger rates and investigate the AC system performance in a second level trigger. The average orbital trigger rate was estimated to be (8.4±0.6)Hz, consisting of (2.0±0.2)Hz good triggers and (6.4±0.5)Hz background. Inclusion of the AC system in the trigger condition to reduce background (for the purpose of data handling capacity) leads to losses of good triggers due to backscattering from the calorimeter (90% loss for 300GeV electrons and 25% for 100GeV protons). A method, using the calorimeter, for identifying backscattering events was investigated and found to reduce the loss of good events to below 1% (300GeV electrons) and 5% (100GeV protons), while maintaining a background reduction of 70%.

X-ray cargo container inspection system with few-view projection imaging

NASA Astrophysics Data System (ADS)

Duan, Xinhui; Cheng, Jianping; Zhang, Li; Xing, Yuxiang; Chen, Zhiqiang; Zhao, Ziran

2009-01-01

An X-ray cargo inspection system with few-view projection imaging is developed for detecting contraband in air containers. This paper describes this developing inspection system, including its configuration and the process of inspection using three imaging modalities: digital radiography (DR), few view imaging and computed tomography (CT). The few-view imaging can provide 3D images with much faster scanning speed than CT and do great help to quickly locate suspicious cargo in a container. An algorithm to reconstruct tomographic images from severely sparse projection data of few-view imaging is discussed. A cooperative work manner of the three modalities is presented to make the inspection more convenient and effective. Numerous experiments of performance tests and modality comparison are performed on our system for inspecting air containers. Results demonstrate the effectiveness of our methods and implementation of few-view imaging in practical inspection systems.

Defocusing effects of lensless ghost imaging and ghost diffraction with partially coherent sources

NASA Astrophysics Data System (ADS)

Zhou, Shuang-Xi; Sheng, Wei; Bi, Yu-Bo; Luo, Chun-Ling

2018-04-01

The defocusing effect is inevitable and degrades the image quality in the conventional optical imaging process significantly due to the close confinement of the imaging lens. Based on classical optical coherent theory and linear algebra, we develop a unified formula to describe the defocusing effects of both lensless ghost imaging (LGI) and lensless ghost diffraction (LGD) systems with a partially coherent source. Numerical examples are given to illustrate the influence of defocusing length on the quality of LGI and LGD. We find that the defocusing effects of the test and reference paths in the LGI or LGD systems are entirely different, while the LGD system is more robust against defocusing than the LGI system. Specifically, we find that the imaging process for LGD systems can be viewed as pinhole imaging, which may find applications in ultra-short-wave band imaging without imaging lenses, e.g. x-ray diffraction and γ-ray imaging.

NASA Tech Briefs, May 2013

NASA Technical Reports Server (NTRS)

2013-01-01

Topics include: Test Waveform Applications for JPL STRS Operating Environment; Pneumatic Proboscis Heat-Flow Probe; Method to Measure Total Noise Temperature of a Wireless Receiver During Operation; Cursor Control Device Test Battery; Functional Near-Infrared Spectroscopy Signals Measure Neuronal Activity in the Cortex; ESD Test Apparatus for Soldering Irons; FPGA-Based X-Ray Detection and Measurement for an X-Ray Polarimeter; Sequential Probability Ratio Test for Spacecraft Collision Avoidance Maneuver Decisions; Silicon/Carbon Nanotube Photocathode for Splitting Water; Advanced Materials and Fabrication Techniques for the Orion Attitude Control Motor; Flight Hardware Packaging Design for Stringent EMC Radiated Emission Requirements; RF Reference Switch for Spaceflight Radiometer Calibration; An Offload NIC for NASA, NLR, and Grid Computing; Multi-Scale CNT-Based Reinforcing Polymer Matrix Composites for Lightweight Structures; Ceramic Adhesive and Methods for On-Orbit Repair of Re-Entry Vehicles; Self-Healing Nanocomposites for Reusable Composite Cryotanks; Pt-Ni and Pt-Co Catalyst Synthesis Route for Fuel Cell Applications; Aerogel-Based Multilayer Insulation with Micrometeoroid Protection; Manufacturing of Nanocomposite Carbon Fibers and Composite Cylinders; Optimized Radiator Geometries for Hot Lunar Thermal Environments; A Mission Concept: Re-Entry Hopper-Aero-Space-Craft System on-Mars (REARM-Mars); New Class of Flow Batteries for Terrestrial and Aerospace Energy Storage Applications; Reliability of CCGA 1152 and CCGA 1272 Interconnect Packages for Extreme Thermal Environments; Using a Blender to Assess the Microbial Density of Encapsulated Organisms; Mixed Integer Programming and Heuristic Scheduling for Space Communication; Video Altimeter and Obstruction Detector for an Aircraft; Control Software for Piezo Stepping Actuators; Galactic Cosmic Ray Event-Based Risk Model (GERM) Code; Sasquatch Footprint Tool; and Multi-User Space Link Extension (SLE) System.

Vibrational effects in x-ray absorption and resonant inelastic x-ray scattering using a semiclassical scheme

NASA Astrophysics Data System (ADS)

Ljungberg, Mathias P.

2017-12-01

A method is presented for describing vibrational effects in x-ray absorption spectroscopy and resonant inelastic x-ray scattering (RIXS) using a combination of the classical Franck-Condon (FC) approximation and classical trajectories run on the core-excited state. The formulation of RIXS is an extension of the semiclassical Kramers-Heisenberg formalism of Ljungberg et al. [Phys. Rev. B 82, 245115 (2010), 10.1103/PhysRevB.82.245115] to the resonant case, retaining approximately the same computational cost. To overcome difficulties with connecting the absorption and emission processes in RIXS, the classical FC approximation is used for the absorption, which is seen to work well provided that a zero-point-energy correction is included. In the case of core-excited states with dissociative character, the method is capable of closely reproducing the main features for one-dimensional test systems, compared to the quantum-mechanical formulation. Due to the good accuracy combined with the relatively low computational cost, the method has great potential of being used for complex systems with many degrees of freedom, such as liquids and surface adsorbates.

Multi-frame X-ray Phase Contrast Imaging (MPCI) for Dynamic Experiments

NASA Astrophysics Data System (ADS)

Iverson, Adam; Carlson, Carl; Sanchez, Nathaniel; Jensen, Brian

2017-06-01

Recent advances in coupling synchrotron X-ray diagnostics to dynamic experiments are providing new information about the response of materials at extremes. For example, propagation based X-ray Phase Contrast Imaging (PCI) which is sensitive to differences in density has been successfully used to study a wide range of phenomena, e.g. jet-formation, compression of additive manufactured (AM) materials, and detonator dynamics. In this talk, we describe the current multi-frame X-ray phase contrast imaging (MPCI) system which allows up to eight frames per experiment, remote optimization, and an improved optical design that increases optical efficiency and accommodates dual-magnification during a dynamic event. Data will be presented that used the dual-magnification feature to obtain multiple images of an exploding foil initiator. In addition, results from static testing will be presented that used a multiple scintillator configuration required to extend the density retrieval to multi-constituent, or heterogeneous systems. The continued development of this diagnostic is fundamentally important to capabilities at the APS including IMPULSE and the Dynamic Compression Sector (DCS), and will benefit future facilities such as MaRIE at Los Alamos National Laboratory.

NAD+ administration significantly attenuates synchrotron radiation X-ray-induced DNA damage and structural alterations of rodent testes

PubMed Central

Sheng, Caibin; Chen, Heyu; Wang, Ban; Liu, Tengyuan; Hong, Yunyi; Shao, Jiaxiang; He, Xin; Ma, Yingxin; Nie, Hui; Liu, Na; Xia, Weiliang; Ying, Weihai

2012-01-01

Synchrotron radiation (SR) X-ray has great potential for its applications in medical imaging and cancer treatment. In order to apply SR X-ray in clinical settings, it is necessary to elucidate the mechanisms underlying the damaging effects of SR X-ray on normal tissues, and to search for the strategies to reduce the detrimental effects of SR X-ray on normal tissues. However, so far there has been little information on these topics. In this study we used the testes of rats as a model to characterize SR X-ray-induced tissue damage, and to test our hypothesis that NAD+ administration can prevent SR X-ray-induced injury of the testes. We first determined the effects of SR X-ray at the doses of 0, 0.5, 1.3, 4 and 40 Gy on the biochemical and structural properties of the testes one day after SR X-ray exposures. We found that 40 Gy of SR X-ray induced a massive increase in double-strand DNA damage, as assessed by both immunostaining and Western blot of phosphorylated H2AX levels, which was significantly decreased by intraperitoneally (i.p.) administered NAD+ at doses of 125 and 625 mg/kg. Forty Gy of SR X-ray can also induce marked increases in abnormal cell nuclei as well as significant decreases in the cell layers of the seminiferous tubules one day after SR X-ray exposures, which were also ameliorated by the NAD+ administration. In summary, our study has shown that SR X-ray can produce both molecular and structural alterations of the testes, which can be significantly attenuated by NAD+ administration. These results have provided not only the first evidence that SR X-ray-induced tissue damage can be ameliorated by certain approaches, but also a valuable basis for elucidating the mechanisms underlying SR X-ray-induced tissue injury. PMID:22518270

The High Resolution Microcalorimeter Soft X-Ray Spectrometer for the Astro-H Mission

NASA Technical Reports Server (NTRS)

Kelley, Richard L.; Mitsuda, Kazuhisa; den Herder, Jan-Willem A.; Aarts, Henri J. M.; Azzarello, Philipp; Boyce, Kevin R.; Brown, Gregory V.; Chiao, Meng P.; de Vries, Cor P.; DiPirro, Michael J.;

Chandra Observations of MS0440.5+0204 & MS0839.9+2938: Cooling Flow Clusters in Formation?

NASA Astrophysics Data System (ADS)

McNamara, Brian

2000-09-01

We propose to observe two redshift z~0.2 clusters, MS0839.9+2938 and MS0440+0204, discovered as bright X-ray sources in the Einstein Medium Sensitivity Survey. The cluster cores are structured in the X-ray and optical bands, and they harbor large cooling flows. Their central cluster galaxies contain luminous nebular emission systems, active star formation, and strong radio sources. Using the Chandra data, we will determine whether the large discrepancies between the X-ray cooling rates and optical star formation rates can be reconciled, and we will test the hypothesis that cooling flows form as cool, dense groups accrete into massive clusters.

Status of the Micro-X Sounding Rocket X-Ray Spectrometer

NASA Technical Reports Server (NTRS)

Goldfinger, D. C.; Adams, J. S.; Baker, R.; Bandler, S. R.; Danowski, M. E.; Doriese, W. B.; Eckart, M. E.; Figueroa-Feliciano, E.; Hilton, G. C.; Hubbard, A. J. F.;

In-Flight Performance of the Soft X-Ray Spectrometer Detector System on ASTRO-H

NASA Technical Reports Server (NTRS)

Porter, Frederick S.; Boyce, Kevin R.; Chiao, Meng P.; Eckart, Megan E.; Fujimoto, Ryuichi; Ishisaki, Yoshitaka; Kelley, Richard L.; Kilbourne, Carolina A.; Leutenegger, Maurice A.; McCammon, Dan;

Development of an X-ray prism for a combined diffraction enhanced imaging and fluorescence imaging system

NASA Astrophysics Data System (ADS)

Bewer, Brian E.

Analyzer crystal based imaging techniques such as diffraction enhanced imaging (DEI) and multiple imaging radiography (MIR) utilize the Bragg peak of perfect crystal diffraction to convert angular changes into intensity changes. These X-ray techniques extend the capability of conventional radiography, which derives image contrast from absorption, by providing a large change in intensity for a small angle change introduced by the X-ray beam traversing the sample. Objects that have very little absorption contrast may have considerable refraction and ultra small angle X-ray scattering (USAXS) contrast thus improving visualization and extending the utility of X-ray imaging. To improve on the current DEI technique this body of work describes the design of an X-ray prism (XRP) included in the imaging system which allows the analyzer crystal to be aligned anywhere on the rocking curve without moving the analyzer from the Bragg angle. By using the XRP to set the rocking curve alignment rather than moving the analyzer crystal physically the needed angle sensitivity is changed from muradians for direct mechanical movement of the analyzer crystal to milliradian control for movement the XRP angle. In addition to using an XRP for the traditional DEI acquisition method of two scans on opposite sides of the rocking curve preliminary tests will be presented showing the potential of using an XRP to scan quickly through the entire rocking curve. This has the benefit of collecting all the required data for image reconstruction in a single fast measurement thus removing the occurrence of motion artifacts for each point or line used during a scan. The XRP design is also intended to be compatible with combined imaging systems where more than one technique is used to investigate a sample. Candidates for complimentary techniques are investigated and measurements from a combined X-ray imaging system are presented.

X-Ray Optics at NASA Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

O'Dell, Stephen L.; Atkins, Carolyn; Broadway, David M.; Elsner, Ronald F.; Gaskin, Jessica A.; Gubarev, Mikhail V.; Kilaru, Kiranmayee; Kolodziejczak, Jeffery J.; Ramsey, Brian D.; Roche, Jacqueline M.;

Non-null full field X-ray mirror metrology using SCOTS: a reflection deflectometry approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su P.; Kaznatcheev K.; Wang, Y.

In a previous paper, the University of Arizona (UA) has developed a measurement technique called: Software Configurable Optical Test System (SCOTS) based on the principle of reflection deflectometry. In this paper, we present results of this very efficient optical metrology method applied to the metrology of X-ray mirrors. We used this technique to measure surface slope errors with precision and accuracy better than 100 nrad (rms) and {approx}200 nrad (rms), respectively, with a lateral resolution of few mm or less. We present results of the calibration of the metrology systems, discuss their accuracy and address the precision in measuring amore » spherical mirror.« less

Spacecraft Materials in the Space Flight Environment: International Space Station - May 2002 to May 2007

NASA Technical Reports Server (NTRS)

Golden, John; Lorenz, Mary J.; Alred, John; Koontz, Steven L.; Pedley, Michael

2008-01-01

The performance of ISS spacecraft materials and systems on prolonged exposure to the low-Earth orbit (LEO) space flight is reported in this paper. In-flight data, flight crew observations, and the results of ground-based test and analysis directly supporting programmatic and operational decision-making are presented. The space flight environments definitions (both natural and induced) used for ISS design, material selection, and verification testing are shown, in most cases, to be more severe than the actual flight environment accounting for the outstanding performance of ISS as a long mission duration spacecraft. No significant ISS material or system failures have been attributed to spacecraft-environments interactions. Nonetheless, ISS materials and systems performance data is contributing to our understanding of spacecraft material interactions in the spaceflight environment so as to reduce cost and risk for future spaceflight projects and programs. Orbital inclination (51.6o) and altitude (nominally near 360 km) determine the set of natural environment factors affecting the functional life of materials and systems on ISS. ISS operates in an electrically conducting environment (the F2 region of Earth s ionosphere) with well-defined fluxes of atomic oxygen, other charged and neutral ionospheric plasma species, solar UV, VUV, and x-ray radiation as well as galactic cosmic rays, trapped radiation, and solar cosmic rays (1-4). The LEO micrometeoroid and orbital debris environment is an especially important determinant of spacecraft design and operations (5, 6). The magnitude of several environmental factors varies dramatically with latitude and longitude as ISS orbits the Earth (1-4). The high latitude orbital environment also exposes ISS to higher fluences of trapped energetic electrons, auroral electrons, solar cosmic rays, and galactic cosmic rays (1-4) than would be the case in lower inclination orbits, largely as a result of the overall shape and magnitude of the geomagnetic field (1-4). As a result, ISS exposure to many environmental factors can vary dramatically along a particular orbital ground track, and from one ground track to the next, during any 24-hour period.

Apparatus for photon activation positron annihilation analysis

DOEpatents

Akers, Douglas W [Idaho Falls, ID

2007-06-12

Non-destructive testing apparatus according to one embodiment of the invention comprises a photon source. The photon source produces photons having predetermined energies and directs the photons toward a specimen being tested. The photons from the photon source result in the creation of positrons within the specimen being tested. A detector positioned adjacent the specimen being tested detects gamma rays produced by annihilation of positrons with electrons. A data processing system operatively associated with the detector produces output data indicative of a lattice characteristic of the specimen being tested.

The 2017 Periastron Passage of PSR B1259-63 in Gamma-rays and X-rays

NASA Astrophysics Data System (ADS)

Wood, Kent S.; Johnson, Tyrel; Ray, Paul S.; Kerr, Matthew T.; Chernyakova, Masha; Fermi LAT Collaboration

2018-01-01

PSR B1259‑ 63 is a 48-ms radio pulsar in a highly eccentric 3.4-yr orbit with a Be star LS 2883. While the pulsed emission has been detected only in radio, un-pulsed radio, X-ray and gamma-ray emission are regularly observed from the binary system around the periastron. It is likely that the collision of the pulsar wind with the anisotropic wind of the Be star plays a crucial role in the generation of the observed non-thermal emission. The spectral energy distribution observed near periastron peaks in GeV gamma-rays, reaching maximum flux several weeks past periastron. In September 2017 it is being observed for a third periastron passage by the Fermi satellite. Here we present first results of the 2017 multi-wavelength campaign. The 2017 observations are compared to the two previous cycles, and used to test current models. Until recently there was no similar source known in the Galaxy but now a near-twin to it, PSR J2032+4127 , (Pspin=143 ms, Porbit ~50 yr, detectable radio to gamma rays) has been found, and is also undergoing periastron passage in Nov 2017. Gamma-ray and X-ray phenomena in the two sources are compared and discussed. These objects may represent a transitional phase, with possible later phases being accreting pulsars, and eventually perhaps NS-BH or NS-NS binary systems. Portions of this research performed at the US Naval Research Laboratory are sponsored by NASA DPR S-15633-Y.

Cross-calibration of Fuji TR image plate and RAR 2492 x-ray film to determine the response of a DITABIS Super Micron image plate scanner

NASA Astrophysics Data System (ADS)

Dunham, G.; Harding, E. C.; Loisel, G. P.; Lake, P. W.; Nielsen-Weber, L. B.

2016-11-01

Fuji TR image plate is frequently used as a replacement detector medium for x-ray imaging and spectroscopy diagnostics at NIF, Omega, and Z facilities. However, the familiar Fuji BAS line of image plate scanners is no longer supported by the industry, and so a replacement scanning system is needed. While the General Electric Typhoon line of scanners could replace the Fuji systems, the shift away from photo stimulated luminescence units to 16-bit grayscale Tag Image File Format (TIFF) leaves a discontinuity when comparing data collected from both systems. For the purposes of quantitative spectroscopy, a known unit of intensity applied to the grayscale values of the TIFF is needed. The DITABIS Super Micron image plate scanning system was tested and shown to potentially rival the resolution and dynamic range of Kodak RAR 2492 x-ray film. However, the absolute sensitivity of the scanner is unknown. In this work, a methodology to cross calibrate Fuji TR image plate and the absolutely calibrated Kodak RAR 2492 x-ray film is presented. Details of the experimental configurations used are included. An energy dependent scale factor to convert Fuji TR IP scanned on a DITABIS Super Micron scanner from 16-bit grayscale TIFF to intensity units (i.e., photons per square micron) is discussed.

Cross-calibration of Fuji TR image plate and RAR 2492 x-ray film to determine the response of a DITABIS Super Micron image plate scanner

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dunham, G., E-mail: gsdunha@sandia.gov; Harding, E. C.; Loisel, G. P.

Fuji TR image plate is frequently used as a replacement detector medium for x-ray imaging and spectroscopy diagnostics at NIF, Omega, and Z facilities. However, the familiar Fuji BAS line of image plate scanners is no longer supported by the industry, and so a replacement scanning system is needed. While the General Electric Typhoon line of scanners could replace the Fuji systems, the shift away from photo stimulated luminescence units to 16-bit grayscale Tag Image File Format (TIFF) leaves a discontinuity when comparing data collected from both systems. For the purposes of quantitative spectroscopy, a known unit of intensity appliedmore » to the grayscale values of the TIFF is needed. The DITABIS Super Micron image plate scanning system was tested and shown to potentially rival the resolution and dynamic range of Kodak RAR 2492 x-ray film. However, the absolute sensitivity of the scanner is unknown. In this work, a methodology to cross calibrate Fuji TR image plate and the absolutely calibrated Kodak RAR 2492 x-ray film is presented. Details of the experimental configurations used are included. An energy dependent scale factor to convert Fuji TR IP scanned on a DITABIS Super Micron scanner from 16-bit grayscale TIFF to intensity units (i.e., photons per square micron) is discussed.« less

Restricted active space calculations of L-edge X-ray absorption spectra: from molecular orbitals to multiplet states.

PubMed

Pinjari, Rahul V; Delcey, Mickaël G; Guo, Meiyuan; Odelius, Michael; Lundberg, Marcus

2014-09-28

The metal L-edge (2p → 3d) X-ray absorption spectra are affected by a number of different interactions: electron-electron repulsion, spin-orbit coupling, and charge transfer between metal and ligands, which makes the simulation of spectra challenging. The core restricted active space (RAS) method is an accurate and flexible approach that can be used to calculate X-ray spectra of a wide range of medium-sized systems without any symmetry constraints. Here, the applicability of the method is tested in detail by simulating three ferric (3d(5)) model systems with well-known electronic structure, viz., atomic Fe(3+), high-spin [FeCl6](3-) with ligand donor bonding, and low-spin [Fe(CN)6](3-) that also has metal backbonding. For these systems, the performance of the core RAS method, which does not require any system-dependent parameters, is comparable to that of the commonly used semi-empirical charge-transfer multiplet model. It handles orbitally degenerate ground states, accurately describes metal-ligand interactions, and includes both single and multiple excitations. The results are sensitive to the choice of orbitals in the active space and this sensitivity can be used to assign spectral features. A method has also been developed to analyze the calculated X-ray spectra using a chemically intuitive molecular orbital picture.

STARLIFE-An International Campaign to Study the Role of Galactic Cosmic Radiation in Astrobiological Model Systems.

PubMed

Moeller, Ralf; Raguse, Marina; Leuko, Stefan; Berger, Thomas; Hellweg, Christine Elisabeth; Fujimori, Akira; Okayasu, Ryuichi; Horneck, Gerda

2017-02-01

In-depth knowledge regarding the biological effects of the radiation field in space is required for assessing the radiation risks in space. To obtain this knowledge, a set of different astrobiological model systems has been studied within the STARLIFE radiation campaign during six irradiation campaigns (2013-2015). The STARLIFE group is an international consortium with the aim to investigate the responses of different astrobiological model systems to the different types of ionizing radiation (X-rays, γ rays, heavy ions) representing major parts of the galactic cosmic radiation spectrum. Low- and high-energy charged particle radiation experiments have been conducted at the Heavy Ion Medical Accelerator in Chiba (HIMAC) facility at the National Institute of Radiological Sciences (NIRS) in Chiba, Japan. X-rays or γ rays were used as reference radiation at the German Aerospace Center (DLR, Cologne, Germany) or Beta-Gamma-Service GmbH (BGS, Wiehl, Germany) to derive the biological efficiency of different radiation qualities. All samples were exposed under identical conditions to the same dose and qualities of ionizing radiation (i) allowing a direct comparison between the tested specimens and (ii) providing information on the impact of the space radiation environment on currently used astrobiological model organisms. Key Words: Space radiation environment-Sparsely ionizing radiation-Densely ionizing radiation-Heavy ions-Gamma radiation-Astrobiological model systems. Astrobiology 17, 101-109.

VETA-I x ray test analysis

NASA Technical Reports Server (NTRS)

Brissenden, R. J. V.; Chartas, G.; Freeman, M. D.; Hughes, J. P.; Kellogg, E. M.; Podgorski, W. A.; Schwartz, D. A.; Zhao, P.

1992-01-01

This interim report presents some definitive results from our analysis of the VETA-I x-ray testing data. It also provides a description of the hardware and software used in the conduct of the VETA-I x-ray test program performed at the MSFC x-ray Calibration Facility (XRCF). These test results also serve to supply data and information to include in the TRW final report required by DPD 692, DR XC04. To provide an authoritative compendium of results, we have taken nine papers as published in the SPIE Symposium, 'Grazing Incidence X-ray/EUV Optics for Astronomy and Projection Lithography' and have reproduced them as the content of this report.

Deviation Value for Conventional X-ray in Hospitals in South Sulawesi Province from 2014 to 2016

NASA Astrophysics Data System (ADS)

Bachtiar, Ilham; Abdullah, Bualkar; Tahir, Dahlan

2018-03-01

This paper describes the conventional X-ray machine parameters tested in the region of South Sulawesi from 2014 to 2016. The objective of this research is to know deviation of every parameter of conventional X-ray machine. The testing parameters were analyzed by using quantitative methods with participatory observational approach. Data collection was performed by testing the output of conventional X-ray plane using non-invasive x-ray multimeter. The test parameters include tube voltage (kV) accuracy, radiation output linearity, reproducibility and radiation beam value (HVL) quality. The results of the analysis show four conventional X-ray test parameters have varying deviation spans, where the tube voltage (kV) accuracy has an average value of 4.12%, the average radiation output linearity is 4.47% of the average reproducibility of 0.62% and the averaged of the radiation beam (HVL) is 3.00 mm.

Image quality assessment and medical physics evaluation of different portable dental X-ray units.

PubMed

Pittayapat, Pisha; Oliveira-Santos, Christiano; Thevissen, Patrick; Michielsen, Koen; Bergans, Niki; Willems, Guy; Debruyckere, Deborah; Jacobs, Reinhilde

2010-09-10

Recently developed portable dental X-ray units increase the mobility of the forensic odontologists and allow more efficient X-ray work in a disaster field, especially when used in combination with digital sensors. This type of machines might also have potential for application in remote areas, military and humanitarian missions, dental care of patients with mobility limitation, as well as imaging in operating rooms. To evaluate radiographic image quality acquired by three portable X-ray devices in combination with four image receptors and to evaluate their medical physics parameters. Images of five samples consisting of four teeth and one formalin-fixed mandible were acquired by one conventional wall-mounted X-ray unit, MinRay 60/70 kVp, used as a clinical standard, and three portable dental X-ray devices: AnyRay 60 kVp, Nomad 60 kVp and Rextar 70 kVp, in combination with a phosphor image plate (PSP), a CCD, or a CMOS sensor. Three observers evaluated images for standard image quality besides forensic diagnostic quality on a 4-point rating scale. Furthermore, all machines underwent tests for occupational as well as patient dosimetry. Statistical analysis showed good quality imaging for all system, with the combination of Nomad and PSP yielding the best score. A significant difference in image quality between the combination of the four X-ray devices and four sensors was established (p<0.05). For patient safety, the exposure rate was determined and exit dose rates for MinRay at 60 kVp, MinRay at 70 kVp, AnyRay, Nomad and Rextar were 3.4 mGy/s, 4.5 mGy/s, 13.5 mGy/s, 3.8 mGy/s and 2.6 mGy/s respectively. The kVp of the AnyRay system was the most stable, with a ripple of 3.7%. Short-term variations in the tube output of all the devices were less than 10%. AnyRay presented higher estimated effective dose than other machines. Occupational dosimetry showed doses at the operator's hand being lowest with protective shielding (Nomad: 0.1 microGy). It was also low while using remote control (distance>1m: Rextar <0.2 microGy, MinRay <0.1 microGy). The present study demonstrated the feasibility of three portable X-ray systems to be used for specific indications, based on acceptable image quality and sufficient accuracy of the machines and following the standard guidelines for radiation hygiene. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Low Velocity Impact Testing and Nondestructive Evaluation of Transparent Materials

NASA Astrophysics Data System (ADS)

Brennan, R. E.; Green, W. H.

2011-06-01

Advanced transparent materials are used in protective systems for enhancing the survivability of ground vehicles, air vehicles, and personnel in applications such as face shields, riot gear, and vehicle windows. Low velocity impact damage can limit visibility and compromise the structural integrity of a transparent system, increasing the likelihood of further damage or penetration from a high velocity impact strike. For this reason, it is critical to determine damage tolerance levels of transparent systems to indicate whether or not a component should be replaced. In this study, transparent laminate systems will be tested by comparing baseline conditions to experimentally controlled damage states. Destructive testing including air gun and sphere impact testing will be used to replicate low velocity impacts in the field. Characterization of the damaged state will include basic visual inspection as well as nondestructive techniques including cross-polarization, x-ray, and ultrasound. The combination of destructive testing and characterization of the resulting damage can help to establish a damage acceptance criterion for materials used in protective systems.

Intraoperative Cochlear Implant Device Testing Utilizing an Automated Remote System: A Prospective Pilot Study.

PubMed

Lohmann, Amanda R; Carlson, Matthew L; Sladen, Douglas P

2018-03-01

Intraoperative cochlear implant device testing provides valuable information regarding device integrity, electrode position, and may assist with determining initial stimulation settings. Manual intraoperative device testing during cochlear implantation requires the time and expertise of a trained audiologist. The purpose of the current study is to investigate the feasibility of using automated remote intraoperative cochlear implant reverse telemetry testing as an alternative to standard testing. Prospective pilot study evaluating intraoperative remote automated impedance and Automatic Neural Response Telemetry (AutoNRT) testing in 34 consecutive cochlear implant surgeries using the Intraoperative Remote Assistant (Cochlear Nucleus CR120). In all cases, remote intraoperative device testing was performed by trained operating room staff. A comparison was made to the "gold standard" of manual testing by an experienced cochlear implant audiologist. Electrode position and absence of tip fold-over was confirmed using plain film x-ray. Automated remote reverse telemetry testing was successfully completed in all patients. Intraoperative x-ray demonstrated normal electrode position without tip fold-over. Average impedance values were significantly higher using standard testing versus CR120 remote testing (standard mean 10.7 kΩ, SD 1.2 vs. CR120 mean 7.5 kΩ, SD 0.7, p < 0.001). There was strong agreement between standard manual testing and remote automated testing with regard to the presence of open or short circuits along the array. There were, however, two cases in which standard testing identified an open circuit, when CR120 testing showed the circuit to be closed. Neural responses were successfully obtained in all patients using both systems. There was no difference in basal electrode responses (standard mean 195.0 μV, SD 14.10 vs. CR120 194.5 μV, SD 14.23; p = 0.7814); however, more favorable (lower μV amplitude) results were obtained with the remote automated system in the apical 10 electrodes (standard 185.4 μV, SD 11.69 vs. CR120 177.0 μV, SD 11.57; p value < 0.001). These preliminary data demonstrate that intraoperative cochlear implant device testing using a remote automated system is feasible. This system may be useful for cochlear implant programs with limited audiology support or for programs looking to streamline intraoperative device testing protocols. Future studies with larger patient enrollment are required to validate these promising, but preliminary, findings.

Calibration of hard x-ray (15 - 50 keV) optics at the MPE test facility PANTER

NASA Astrophysics Data System (ADS)

Bräuninger, Heinrich; Burkert, Wolfgang; Hartner, Gisela D.; Citterio, Oberto; Ghigo, Mauro; Mazzoleni, Francesco; Pareschi, Giovanni; Spiga, Daniele

2004-02-01

The Max-Planck-Institut für extraterrestrische Physik (MPE) in Garching, Germany, operates the large X-ray beam line facility PANTER for testing astronomical systems. At PANTER a number of telescopes like EXOSAT, ROSAT, SAX, JET-X, ABRIXAS, XMM and SWIFT operating in the soft energy range (0.02 - 15 keV) have been successfully calibrated. In the present paper we report on an important upgrade recently implemented that enables the calibration of hard X-ray optics (from 15 up to 50 keV). Currently hard X-ray optics based on single and multilayer coating are being developed for several future X-ray missions. The hard X-ray calibrations at PANTER are carried out by a high energy source based on an electron gun and several anodes, able to cover the energy range from 4.5 up to 50 keV. It provides fluxes up to 104 counts/sec/cm2 at the instrument chamber with a stability better than 1%. As detector a pn-CCD camera operating between 0.2 and 50 keV and a collecting area of 36 cm2 is used. Taking into account the high energy resolution of the CCD (145 eV at 6 keV), a very easy way to operate the facility in hard X-ray is in energy-dispersive mode (i.e. with a broad-band beam). A double crystal monochromator is also available providing energies up to 20 keV. In this paper we present the first results obtained by using PANTER for hard X-ray characterizations, performed on prototype multilayer optics developed by the Osservatorio Astronomico di Brera (OAB), Milano, Italy, and the Harvard-Smithsonian Center for Astrophysics (CfA), Cambridge, MA, USA.

Design and Analysis of the International X-Ray Observatory Mirror Modules

NASA Technical Reports Server (NTRS)

McClelland, Ryan S.; Carnahan, Timothy M.; Robinson, David W.; Saha, Timo T.

2009-01-01

The Soft X-Ray Telescope (SXT) modules are the fundamental focusing assemblies on NASA's next major X-ray telescope mission, the International X-Ray Observatory (IXO). The preliminary design and analysis of these assemblies has been completed, addressing the major engineering challenges and leading to an understanding of the factors effecting module performance. Each of the 60 modules in the Flight Mirror Assembly (FMA) supports 200-300 densely packed 0.4 mm thick glass mirror segments in order to meet the unprecedented effective area required to achieve the scientific objectives of the mission. Detailed Finite Element Analysis (FEA), materials testing, and environmental testing have been completed to ensure the modules can be successfully launched. Resulting stress margins are positive based on detailed FEA, a large factor of safety, and a design strength determined by robust characterization of the glass properties. FEA correlates well with the results of the successful modal, vibration, and acoustic environmental tests. Deformation of the module due to on-orbit thermal conditions is also a major design driver. A preliminary thermal control system has been designed and the sensitivity of module optical performance to various thermal loads has been determined using optomechanical analysis methods developed for this unique assembly. This design and analysis furthers the goal of building a module that demonstrates the ability to meet IXO requirements, which is the current focus of the IXO FMA technology development team.

Imaging performance of a Timepix detector based on semi-insulating GaAs

NASA Astrophysics Data System (ADS)

Zaťko, B.; Zápražný, Z.; Jakůbek, J.; Šagátová, A.; Boháček, P.; Sekáčová, M.; Korytár, D.; Nečas, V.; Žemlička, J.; Mora, Y.; Pichotka, M.

2018-01-01

This work focused on a Timepix chip [1] coupled with a bulk semi-insulating GaAs sensor. The sensor consisted of a matrix of 256 × 256 pixels with a pitch of 55 μm bump-bonded to a Timepix ASIC. The sensor was processed on a 350 μm-thick SI GaAs wafer. We carried out detector adjustment to optimize its performance. This included threshold equalization with setting up parameters of the Timepix chip, such as Ikrum, Pream, Vfbk, and so on. The energy calibration of the GaAs Timepix detector was realized using a 241Am radioisotope in two Timepix detector modes: time-over-threshold and threshold scan. An energy resolution of 4.4 keV in FWHM (Full Width at Half Maximum) was observed for 59.5 keV γ-photons using threshold scan mode. The X-ray imaging quality of the GaAs Timepix detector was tested using various samples irradiated by an X-ray source with a focal spot size smaller than 8 μm and accelerating voltage up to 80 kV. A 700 μm × 700 μm gold testing object (X-500-200-16Au with Siemens star) fabricated with high precision was used for the spatial resolution testing at different values of X-ray image magnification (up to 45). The measured spatial resolution of our X-ray imaging system was about 4 μm.

10 CFR 830.3 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... research and experimental and analytical laboratory activities, electron microscopes, and X-ray machines... research, test, and power reactors, and critical and pulsed assemblies and any assembly that is designed to... covering a topic such as: quality assurance; maintenance of safety systems; personnel training; conduct of...

Final Report, Next-Generation Mega-Voltage Cargo-Imaging System for Cargo Conainer Inspection, March 2007

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dr. James Clayton, Ph.D., Varian Medical Systems-Security & Inspection Products; Dr. Emma Regentova, Ph.D, University of Nevada Las Vegas; Dr. Evangelos Yfantis, Ph.D., University of Nevada, Las Vegas

The UNLV Research Foundation, as the primary award recipient, teamed with Varian Medical Systems-Security & Inspection Products and the University of Nevada Las Vegas (UNLV) for the purpose of conducting research and engineering related to a "next-generation" mega-voltage imaging (MVCI) system for inspection of cargo in large containers. The procurement and build-out of hardware for the MVCI project has been completed. The K-9 linear accelerator and an optimized X-ray detection system capable of efficiently detecting X-rays emitted from the accelerator after they have passed through the device is under test. The Office of Science financial assistance award has made possiblemore » the development of a system utilizing a technology which will have a profound positive impact on the security of U.S. seaports. The proposed project will ultimately result in critical research and development advances for the "next-generation" Linatron X-ray accelerator technology, thereby providing a safe, reliable and efficient fixed and mobile cargo inspection system, which will very significantly increase the fraction of cargo containers undergoing reliable inspection as the enter U.S. ports. Both NNSA/NA-22 and the Department of Homeland Security's Domestic Nuclear Detection Office are collaborating with UNLV and its team to make this technology available as soon as possible.« less

Development of a 6LiF/ZnS-based Neutron Multiplicity Counter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stave, Sean C.; Behling, Richard S.; Bernacki, Bruce E.

2016-10-06

Abstract–Neutron multiplicity counters are used in safeguards to provide rapid assay of samples which contain an unknown amount of plutonium in a potentially unknown configuration. A project at PNNL is using regular and nickel-quenched 6LiF/ZnS neutron-scintillator sheets and wavelength shifting plastic for light pipes in place of 3He. A combination of laboratory and modeling work predicts a LiF/ZnS-based system to be able to match or exceed the performance of the best 3He-based systems available. Also, the Ni-quenched material is expected to allow for improved neutron/gamma-ray discrimination at twice the event rate relative to the non-Ni-quenched LiF/ZnS. A new system basedmore » on the LiF/ZnS material is under construction and components are being used to optimize the detection efficiency and neutron/gamma-ray discrimination properties. Components of the new system are partially constructed and undergoing performance testing utilizing high-speed digitizers with field programmable gate arrays to perform the neutron/gamma-ray discrimination. The expected performance of the full-scale system is expected to be nearly the same as for 3He-based systems and is due for completion in 2016.« less

A High Frame Rate Test System for the HEPS-BPIX Based on NI-sbRIO Board

NASA Astrophysics Data System (ADS)

Gu, Jingzi; Zhang, Jie; Wei, Wei; Ning, Zhe; Li, Zhenjie; Jiang, Xiaoshan; Fan, Lei; Shen, Wei; Ren, Jiayi; Ji, Xiaolu; Lan, Allan K.; Lu, Yunpeng; Ouyang, Qun; Liu, Peng; Zhu, Kejun; Wang, Zheng

2017-06-01

HEPS-BPIX is a silicon pixel detector designed for the future large scientific facility, high-energy photon sources (HEPS) in Beijing, China. It is a high frame rate hybrid pixel detector which works in the single-photon-counting mode. High frame rate leads to much higher readout data bandwidth than former systems, which is also the difficulty of the design. Aiming to test and calibrate the pixel detector, a test system based on the National Instruments single-board RIO 9626 and LabVIEW program environment has been designed. A series of tests has been carried out with X-ray machine as well as on the Beijing Synchrotron Radiation Facility 1W2B beamline. The test results show that the threshold uniformity is better than 60 electrons and the equivalent noise charge is less than 120 electrons. Besides, the required highest frame rate of 1.2 kHz has been realized. This paper will elaborate the test system design and present the latest testing results of the HEPS-BPIX system.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1977-01-01

This photograph is of the High Energy Astronomy Observatory (HEAO)-2 telescope being evaluated by engineers in the clean room of the X-Ray Calibration Facility at the Marshall Space Flight Center (MSFC). The MSFC was heavily engaged in the technical and scientific aspects, testing and calibration, of the HEAO-2 telescope The HEAO-2 was the first imaging and largest x-ray telescope built to date. The X-Ray Calibration Facility was built in 1976 for testing MSFC's HEAO-2. The facility is the world's largest, most advanced laboratory for simulating x-ray emissions from distant celestial objects. It produced a space-like environment in which components related to x-ray telescope imaging are tested and the quality of their performance in space is predicted. The original facility contained a 1,000-foot long by 3-foot diameter vacuum tube (for the x-ray path) cornecting an x-ray generator and an instrument test chamber. Recently, the facility was upgraded to evaluate the optical elements of NASA's Hubble Space Telescope, Chandra X-Ray Observatory and Compton Gamma-Ray Observatory.

Quantification technology study on flaws in steam-filled pipelines based on image processing

NASA Astrophysics Data System (ADS)

Yuan, Pei-xin; Cong, Jia-hui; Chen, Bo

2008-03-01

Starting from exploiting the applied detection system of gas transmission pipeline, a set of X-ray image processing methods and pipeline flaw quantificational evaluation methods are proposed. Defective and non-defective strings and rows in gray image were extracted and oscillogram was obtained. We can distinguish defects in contrast with two gray images division. According to the gray value of defects with different thicknesses, the gray level depth curve is founded. Through exponential and polynomial fitting way to obtain the attenuation mathematical model which the beam penetrates pipeline, thus attain flaw deep dimension. This paper tests on the PPR pipe in the production of simulated holes flaw and cracks flaw. The X-ray source tube voltage was selected as 130kv and valve current was 1.5mA.Test results show that X-ray image processing methods, which meet the needs of high efficient flaw detection and provide quality safeguard for thick oil recovery, can be used successfully in detecting corrosion of insulated pipe.

Transverse beam motion on the second axis of the dual axis radiographic hydrodynamic test facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caporaso, G J; Chen, Y J; Fawley, W M

1999-03-23

The accelerator on the second-axis of the Dual-Axis Radiographic Hydrodynamic Test (DARHT-II) facility will generate a 20 MeV, 2-4 kA, 2 µs long electron beam with an energy variation {<=} ± 0.5%. Four short current pulses with various lengths will be selected out of this 2 µs long current pulse and delivered to an x-ray converter target. The DARHT-II radiographic resolution requires these electron pulses to be focused to sub-millimeter spots on Bremsstrahlung targets with peak-to-peak transverse beam motion less than a few hundred microns. We have modeled the transverse beam motion, including the beam breakup instability, corkscrew motion, transversemore » resistive wall instability and beam induced transverse deflection in the kicker system, from the DARHT-II injector exit to the x-ray converter target. Simulations show that the transverse motion at the x-ray converters satisfies the DARHT-II radiographic requirements.« less

Differential phase contrast X-ray imaging system and components

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stutman, Daniel; Finkenthal, Michael

2017-11-21

A differential phase contrast X-ray imaging system includes an X-ray illumination system, a beam splitter arranged in an optical path of the X-ray illumination system, and a detection system arranged in an optical path to detect X-rays after passing through the beam splitter.

Performance evaluation of a direct-conversion flat-panel detector system in imaging and quality assurance for a high-dose-rate 192Ir source

NASA Astrophysics Data System (ADS)

Miyahara, Yoshinori; Hara, Yuki; Nakashima, Hiroto; Nishimura, Tomonori; Itakura, Kanae; Inomata, Taisuke; Kitagaki, Hajime

2018-03-01

In high-dose-rate (HDR) brachytherapy, a direct-conversion flat-panel detector (d-FPD) clearly depicts a 192Ir source without image halation, even under the emission of high-energy gamma rays. However, it was unknown why iridium is visible when using a d-FPD. The purpose of this study was to clarify the reasons for visibility of the source core based on physical imaging characteristics, including the modulation transfer functions (MTF), noise power spectral (NPS), contrast transfer functions, and linearity of d-FPD to high-energy gamma rays. The acquired data included: x-rays, [X]; gamma rays, [γ] dual rays (X  +  γ), [D], and subtracted data for depicting the source ([D]  -  [γ]). In the quality assurance (QA) test for the positional accuracy of a source core, the coordinates of each dwelling point were compared between the planned and actual source core positions using a CT/MR-compatible ovoid applicator and a Fletcher-Williamson applicator. The profile curves of [X] and ([D]  -  [γ]) matched well on MTF and NPS. The contrast resolutions of [D] and [X] were equivalent. A strongly positive linear correlation was found between the output data of [γ] and source strength (r 2  >  0.99). With regard to the accuracy of the source core position, the largest coordinate difference (3D distance) was noted at the maximum curvature of the CT/MR-compatible ovoid and Fletcher-Williamson applicators, showing 1.74  ±  0.02 mm and 1.01  ±  0.01 mm, respectively. A d-FPD system provides high-quality images of a source, even when high-energy gamma rays are emitted to the detector, and positional accuracy tests with clinical applicators are useful in identifying source positions (source movements) within the applicator for QA.

Fluence-field modulated x-ray CT using multiple aperture devices

NASA Astrophysics Data System (ADS)

Stayman, J. Webster; Mathews, Aswin; Zbijewski, Wojciech; Gang, Grace; Siewerdsen, Jeffrey; Kawamoto, Satomi; Blevis, Ira; Levinson, Reuven

2016-03-01

We introduce a novel strategy for fluence field modulation (FFM) in x-ray CT using multiple aperture devices (MADs). MAD filters permit FFM by blocking or transmitting the x-ray beam on a fine (0.1-1 mm) scale. The filters have a number of potential advantages over other beam modulation strategies including the potential for a highly compact design, modest actuation speed and acceleration requirements, and spectrally neutral filtration due to their essentially binary action. In this work, we present the underlying MAD filtration concept including a design process to achieve a specific class of FFM patterns. A set of MAD filters is fabricated using a tungsten laser sintering process and integrated into an x-ray CT test bench. A characterization of the MAD filters is conducted and compared to traditional attenuating bowtie filters and the ability to flatten the fluence profile for a 32 cm acrylic phantom is demonstrated. MAD-filtered tomographic data was acquired on the CT test bench and reconstructed without artifacts associated with the MAD filter. These initial studies suggest that MAD-based FFM is appropriate for integration in clinical CT system to create patient-specific fluence field profile and reduce radiation exposures.

X-ray and gamma-ray computed tomography for industrial nondestructive testing and evaluation

NASA Astrophysics Data System (ADS)

Costello, Ian; Wells, Peter; Davis, John R.; Benci, Nino; Skerrett, David; Davies, D. R.

1994-03-01

This paper presents an overview of two recently constructed computed tomography (CT) scanners that have been designed to provide structural information for industrially relevant materials and components. CT enables cross-sectional slices of an object to be nondestructively imaged and represented as a map of linear attenuation coefficient. As linear attenuation is the product of mass attenuation and density, this usually enables a straightforward interpretation of the image in terms of density. The two instruments are a transportable scanner using a 160 kV(peak) powered x-ray tube for the inspection of wooden power poles up to 450 mm in diameter, and an industrial scanning system designed around an Ir-192 gamma-ray source for materials characterization and the testing and evaluation of castings, ceramics, and composites. The images presented in this paper have generally been reconstructed using the summation convolution back-projection (SCBP) method, and this technique is outlined. Direct Fourier reconstruction is also used and compared with the SCBP method. A brief discussion is offered on incorporating edge detection methods into the image reconstruction process for the improved identification of defects such as cracks and voids.

An investigation of error correcting techniques for OMV data

NASA Technical Reports Server (NTRS)

Ingels, Frank; Fryer, John

1992-01-01

Papers on the following topics are presented: considerations of testing the Orbital Maneuvering Vehicle (OMV) system with CLASS; OMV CLASS test results (first go around); equivalent system gain available from R-S encoding versus a desire to lower the power amplifier from 25 watts to 20 watts for OMV; command word acceptance/rejection rates for OMV; a memo concerning energy-to-noise ratio for the Viterbi-BSC Channel and the impact of Manchester coding loss; and an investigation of error correcting techniques for OMV and Advanced X-ray Astrophysics Facility (AXAF).

Optical design and testing: introduction.

PubMed

Liang, Chao-Wen; Koshel, John; Sasian, Jose; Breault, Robert; Wang, Yongtian; Fang, Yi Chin

2014-10-10

Optical design and testing has numerous applications in industrial, military, consumer, and medical settings. Assembling a complete imaging or nonimage optical system may require the integration of optics, mechatronics, lighting technology, optimization, ray tracing, aberration analysis, image processing, tolerance compensation, and display rendering. This issue features original research ranging from the optical design of image and nonimage optical stimuli for human perception, optics applications, bio-optics applications, 3D display, solar energy system, opto-mechatronics to novel imaging or nonimage modalities in visible and infrared spectral imaging, modulation transfer function measurement, and innovative interferometry.

Determination of seed viability of eight wild Saudi Arabian species by germination and X-ray tests.

PubMed

Al-Turki, Turki A; Baskin, Carol C

2017-05-01

Our purpose was to evaluate the usefulness of the germination vs. the X-ray test in determining the initial viability of seeds of eight wild species ( Salvia spinosa , Salvia aegyptiaca , Ochradenus baccatus , Ochradenus arabicus , Suaeda aegyptiaca , Suaeda vermiculata , Prosopisfarcta and Panicumturgidum ) from Saudi Arabia. Several days were required to determine viability of all eight species via germination tests, while immediate results on filled/viable seeds were obtained with the X-ray test. Seeds of all the species, except Sa.aegyptiaca , showed high viability in both the germination (98-70% at 25/15 °C, 93-66% at 35/25 °C) and X-ray (100-75%) test. Furthermore, there was general agreement between the germination (10% at 25/15 °C and 8% at 35/25 °C) and X-ray (5%) tests that seed viability of Sa.aegyptiaca was very low, and X-ray analysis revealed that this was due to poor embryo development. Seeds of P.farcta have physical dormancy, which was broken by scarification in concentrated sulfuric acid (10 min), and they exhibited high viability in both the germination (98% at 25/15 °C and 93% at 35/25 °C) and X-ray (98%) test. Most of the nongerminated seeds of the eight species except those of Sa.aegyptiaca were alive as judged by the tetrazolium test (TZ). Thus, for the eight species examined, the X-ray test was a good and rapid predictor of seed viability.

Seed viability of five wild Saudi Arabian species by germination and X-ray tests.

PubMed

Al-Hammad, B A; Al-Ammari, B S

2017-09-01

Our objective was to evaluate the usefulness of the germination vs. the X-ray test in determining the initial viability of seeds of five wild species ( Moringa peregrina , Abrus precatorius , Arthrocnemum macrostachyum , Acacia ehrenbergiana and Acacia tortilis ) from Saudi Arabia. Usually several days were required to determine the viability of all five species via germination tests. However, X-ray test will give immediate results on filled/viable seeds. Seeds of all species, except Acacia ehrenbergiana and Acacia tortilis showed high viability in both germination (96-72% at 25/15 °C, 94-70% at 35/25 °C) and X-ray (100-80%) test. Furthermore, there was a general agreement between the germination (19%, 14% at 25/15 °C and 17% and 12% at 35/25 °C) and X-ray (8%, 4%) tests in which seed viability of Acacia ehrenbergiana and Acacia tortilis was very low due to insect damaged embryo as shown in X-ray analysis. Seeds of Abruspreca torius have physical dormancy, which was broken by scarification in concentrated sulfuric acid (10 min), and they exhibited high viability in both the germination (83% at 25/15 °C and 81% at 35/25 °C) and X-ray (96%) tests. Most of the nongerminated seeds of the five species except those of Acacia ehrenbergiana and Acacia tortilis , were alive as judged by the tetrazolium test (TZ). Thus, for the five species examined, the X-ray test was proved to be a good and rapid predictor of seed viability.

X-ray verification of an optically aligned off-plane grating module

NASA Astrophysics Data System (ADS)

Donovan, Benjamin D.; McEntaffer, Randall L.; Tutt, James H.; DeRoo, Casey T.; Allured, Ryan; Gaskin, Jessica A.; Kolodziejczak, Jeffery J.

2018-01-01

Off-plane x-ray reflection gratings are theoretically capable of achieving high resolution and high diffraction efficiencies over the soft x-ray bandpass, making them an ideal technology to implement on upcoming x-ray spectroscopy missions. To achieve high effective area, these gratings must be aligned into grating modules. X-ray testing was performed on an aligned grating module to assess the current optical alignment methods. Results indicate that the grating module achieved the desired alignment for an upcoming x-ray spectroscopy suborbital rocket payload with modest effective area and resolving power. These tests have also outlined a pathway towards achieving the stricter alignment tolerances of future x-ray spectrometer payloads, which require improvements in alignment metrology, grating fabrication, and testing techniques.

Real-time stereographic display of volumetric datasets in radiology

NASA Astrophysics Data System (ADS)

Wang, Xiao Hui; Maitz, Glenn S.; Leader, J. K.; Good, Walter F.

2006-02-01

A workstation for testing the efficacy of stereographic displays for applications in radiology has been developed, and is currently being tested on lung CT exams acquired for lung cancer screening. The system exploits pre-staged rendering to achieve real-time dynamic display of slabs, where slab thickness, axial position, rendering method, brightness and contrast are interactively controlled by viewers. Stereo presentation is achieved by use of either frame-swapping images or cross-polarizing images. The system enables viewers to toggle between alternative renderings such as one using distance-weighted ray casting by maximum-intensity-projection, which is optimal for detection of small features in many cases, and ray casting by distance-weighted averaging, for characterizing features once detected. A reporting mechanism is provided which allows viewers to use a stereo cursor to measure and mark the 3D locations of specific features of interest, after which a pop-up dialog box appears for entering findings. The system's impact on performance is being tested on chest CT exams for lung cancer screening. Radiologists' subjective assessments have been solicited for other kinds of 3D exams (e.g., breast MRI) and their responses have been positive. Objective estimates of changes in performance and efficiency, however, must await the conclusion of our study.

A mercuric detector system for X-ray astronomy. 2. Results from flight tests of a balloon borne instrument

NASA Technical Reports Server (NTRS)

Vallerga, J.; Vanderspek, R. K.; Ricker, G. R.

1982-01-01

To establish the expected sensitivity of a new hard X-ray telescope design, an experiment was conducted to measure the background counting rate at balloon altitudes (40 km) of mercuric iodide, a room temperature solid state X-ray detector. The prototype detector consisted of two thin mercuric iodide (HgI2) detectors surrounded by a large bismuth germanate (Bi4Ge3O12) scintillator operated in anticoincidence. The bismuth germanate shield vetoed most of the background counting rate induced by atmospheric gamma-rays, neutrons and cosmic rays. A balloon-borne gondola containing a prototype detector assembly was designed, constructed and flown twice in the spring of 1982 from Palestine, Texas. The second flight of this instrument established a differential background counting rate of 4.2 O.7 x 10-5 counts/sec cm keV over the energy range of 40 to 80 keV. This measurement was within 50% of the predicted value. The measured rate is approx 5 times lower than previously achieved in shielded NaI/CsI or Ge systems operating in the same energy range. The prediction was based on a Monte Carlo simulation of the detector assembly in the radiation environment at float altitude.

SEXTANT - Station Explorer for X-ray Timing and Navigation Technology

NASA Technical Reports Server (NTRS)

Mitchell, Jason W.; Hasouneh, Munther Abdel Hamid; Winternitz, Luke M. B.; Valdez, Jennifer E.; Price, Samuel R.; Semper, Sean R.; Yu, Wayne H.; Arzoumanian, Zaven; Ray, Paul S.; Wood, Kent S.;

Development of Rhizo-Columns for Nondestructive Root System Architecture Laboratory Measurements

NASA Astrophysics Data System (ADS)

Oostrom, M.; Johnson, T. J.; Varga, T.; Hess, N. J.; Wietsma, T. W.

2016-12-01

Numerical models for root water uptake in plant-soil systems have been developing rapidly, increasing the demand for laboratory experimental data to test and verify these models. Most of the increasingly detailed models are either compared to long-term field crop data or do not involve comparisons at all. Ideally, experiments would provide information on dynamic root system architecture (RSA) in combination with soil-pant hydraulics such as water pressures and volumetric water contents. Data obtained from emerging methods such as Spectral Induced Polarization (SIP) and x-ray computed tomography (x-ray CT) may be used to provide laboratory RSA data needed for model comparisons. Point measurements such as polymer tensiometers (PT) may provide soil moisture information over a large range of water pressures, from field capacity to the wilting point under drought conditions. In the presentation, we demonstrate a novel laboratory capability allowing for detailed RSA studies in large columns under controlled conditions using automated SIP, X-ray CT, and PT methods. Examples are shown for pea and corn root development under various moisture regimes.

Cosmic Ray Inspection and Passive Tomography for SNM Detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Armitage, John; Oakham, Gerald; Bryman, Douglas

2009-12-02

The Cosmic Ray Inspection and Passive Tomography (CRIPT) project has recently started investigating the detection of illicit Special Nuclear Material in cargo using cosmic ray muon tomography and complementary neutron detectors. We are currently performing simulation studies to help with the design of small scale prototypes. Based on the prototype tests and refined simulations, we will determine whether the muon tracking system for the full scale prototype will be based on drift chambers or extruded scintillator trackers. An analysis of the operations of the Port of Montreal has determined how long muon scan times should take if all or amore » subset of the cargo is to be screened. As long as the throughput of the muon system(s) is equal to the rate at which containers are unloaded from ships, the impact on port operations would not be great if a muon scanning stage were required for all cargo. We also show preliminary simulation results indicating that excellent separation between Al, Fe and Pb is possible under ideal conditions. The discrimination power is reduced but still significant when realistic momentum resolution measurements are considered.« less

Cosmic Ray Inspection and Passive Tomography for SNM Detection

NASA Astrophysics Data System (ADS)

Armitage, John; Bryman, Douglas; Cousins, Thomas; Gallant, Grant; Jason, Andrew; Jonkmans, Guy; Noël, Scott; Oakham, Gerald; Stocki, Trevor J.; Waller, David

2009-12-01

The Cosmic Ray Inspection and Passive Tomography (CRIPT) project has recently started investigating the detection of illicit Special Nuclear Material in cargo using cosmic ray muon tomography and complementary neutron detectors. We are currently performing simulation studies to help with the design of small scale prototypes. Based on the prototype tests and refined simulations, we will determine whether the muon tracking system for the full scale prototype will be based on drift chambers or extruded scintillator trackers. An analysis of the operations of the Port of Montreal has determined how long muon scan times should take if all or a subset of the cargo is to be screened. As long as the throughput of the muon system(s) is equal to the rate at which containers are unloaded from ships, the impact on port operations would not be great if a muon scanning stage were required for all cargo. We also show preliminary simulation results indicating that excellent separation between Al, Fe and Pb is possible under ideal conditions. The discrimination power is reduced but still significant when realistic momentum resolution measurements are considered.

49 CFR 1546.209 - Use of X-ray systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 9 2012-10-01 2012-10-01 false Use of X-ray systems. 1546.209 Section 1546.209... Use of X-ray systems. (a) TSA authorization required. No foreign air carrier may use any X-ray system... security program. TSA authorizes foreign air carriers to use X-ray systems for inspecting accessible...

A comprehensive model for x-ray projection imaging system efficiency and image quality characterization in the presence of scattered radiation

NASA Astrophysics Data System (ADS)

Monnin, P.; Verdun, F. R.; Bosmans, H.; Rodríguez Pérez, S.; Marshall, N. W.

2017-07-01

This work proposes a method for assessing the detective quantum efficiency (DQE) of radiographic imaging systems that include both the x-ray detector and the antiscatter device. Cascaded linear analysis of the antiscatter device efficiency (DQEASD) with the x-ray detector DQE is used to develop a metric of system efficiency (DQEsys); the new metric is then related to the existing system efficiency parameters of effective DQE (eDQE) and generalized DQE (gDQE). The effect of scatter on signal transfer was modelled through its point spread function (PSF), leading to an x-ray beam transfer function (BTF) that multiplies with the classical presampling modulation transfer function (MTF) to give the system MTF. Expressions are then derived for the influence of scattered radiation on signal-difference to noise ratio (SDNR) and contrast-detail (c-d) detectability. The DQEsys metric was tested using two digital mammography systems, for eight x-ray beams (four with and four without scatter), matched in terms of effective energy. The model was validated through measurements of contrast, SDNR and MTF for poly(methyl)methacrylate thicknesses covering the range of scatter fractions expected in mammography. The metric also successfully predicted changes in c-d detectability for different scatter conditions. Scatter fractions for the four beams with scatter were established with the beam stop method using an extrapolation function derived from the scatter PSF, and validated through Monte Carlo (MC) simulations. Low-frequency drop of the MTF from scatter was compared to both theory and MC calculations. DQEsys successfully quantified the influence of the grid on SDNR and accurately gave the break-even object thickness at which system efficiency was improved by the grid. The DQEsys metric is proposed as an extension of current detector characterization methods to include a performance evaluation in the presence of scattered radiation, with an antiscatter device in place.

Dual-CGH interferometry test for x-ray mirror mandrels

NASA Astrophysics Data System (ADS)

Gao, Guangjun; Lehan, John P.; Griesmann, Ulf

2009-06-01

We describe a glancing-incidence interferometric double-pass test, based on a pair of computer-generated holograms (CGHs), for mandrels used to fabricate x-ray mirrors for space-based x-ray telescopes. The design of the test and its realization are described. The application illustrates the advantage of dual-CGH tests for the complete metrology of precise optical surfaces.

X-ray Cryogenic Facility (XRCF) Handbook

NASA Technical Reports Server (NTRS)

Kegley, Jeffrey R.

2016-01-01

The X-ray & Cryogenic Facility (XRCF) Handbook is a guide for planning operations at the facility. A summary of the capabilities, policies, and procedures is provided to enhance project coordination between the facility user and XRCF personnel. This handbook includes basic information that will enable the XRCF to effectively plan and support test activities. In addition, this handbook describes the facilities and systems available at the XRCF for supporting test operations. 1.2 General Facility Description The XRCF was built in 1989 to meet the stringent requirements associated with calibration of X-ray optics, instruments, and telescopes and was subsequently modified in 1999 & 2005 to perform the challenging cryogenic verification of Ultraviolet, Optical, and Infrared mirrors. These unique and premier specialty capabilities, coupled with its ability to meet multiple generic thermal vacuum test requirements for large payloads, make the XRCF the most versatile and adaptable space environmental test facility in the Agency. XRCF is also recognized as the newest, most cost effective, most highly utilized facility in the portfolio and as one of only five NASA facilities having unique capabilities. The XRCF is capable of supporting and has supported missions during all phases from technology development to flight verification. Programs/projects that have benefited from XRCF include Chandra, Solar X-ray Imager, Hinode, and James Webb Space Telescope. All test programs have been completed on-schedule and within budget and have experienced no delays due to facility readiness or failures. XRCF is currently supporting Strategic Astrophysics Technology Development for Cosmic Origins. Throughout the years, XRCF has partnered with and continues to maintain positive working relationships with organizations such as ATK, Ball Aerospace, Northrop Grumman Aerospace, Excelis (formerly Kodak/ITT), Smithsonian Astrophysical Observatory, Goddard Space Flight Center, University of Alabama Huntsville, and more.

Digital fast neutron radiography of steel reinforcing bar in concrete

NASA Astrophysics Data System (ADS)

Mitton, K.; Jones, A.; Joyce, M. J.

2014-12-01

Neutron imaging has previously been used in order to test for cracks, degradation and water content in concrete. However, these techniques often fall short of alternative non-destructive testing methods, such as γ-ray and X-ray imaging, particularly in terms of resolution. Further, thermal neutron techniques can be compromised by the significant expense associated with thermal neutron sources of sufficient intensity to yield satisfactory results that can often precipitate the need for a reactor. Such embodiments are clearly not portable in the context of the needs of field applications. This paper summarises the results of a study to investigate the potential for transmission radiography based on fast neutrons. The objective of this study was to determine whether the presence of heterogeneities in concrete, such as reinforcement structures, could be identified on the basis of variation in transmitted fast-neutron flux. Monte-Carlo simulations have been performed and the results from these are compared to those arising from practical tests using a 252Cf source. The experimental data have been acquired using a digital pulse-shape discrimination system that enables fast neutron transmission to be studied across an array of liquid scintillators placed in close proximity to samples under test, and read out in real time. Whilst this study does not yield sufficient spatial resolution, a comparison of overall flux ratios does provide a basis for the discrimination between samples with contrasting rebar content. This approach offers the potential for non-destructive testing that gives less dose, better transportability and better accessibility than competing approaches. It is also suitable for thick samples where γ-ray and X-ray methods can be limited.

Development of a high performance surface slope measuring system for two-dimensional mapping of x-ray optics

NASA Astrophysics Data System (ADS)

Lacey, Ian; Adam, Jérôme; Centers, Gary P.; Gevorkyan, Gevork S.; Nikitin, Sergey M.; Smith, Brian V.; Yashchuk, Valeriy V.

2017-09-01

The research and development work on the Advanced Light Source (ALS) upgrade to a diffraction limited storage ring light source, ALS-U, has brought to focus the need for near-perfect x-ray optics, capable of delivering light to experiments without significant degradation of brightness and coherence. The desired surface quality is characterized with residual (after subtraction of an ideal shape) surface slope and height errors of <50-100 nrad (rms) and <1-2 nm (rms), respectively. The ex-situ metrology that supports the optimal usage of the optics at the beamlines has to offer even higher measurement accuracy. At the ALS X-Ray Optics Laboratory, we are developing a new surface slope profiler, the Optical Surface Measuring System (OSMS), capable of two-dimensional (2D) surface-slope metrology at an absolute accuracy below the above optical specification. In this article we provide the results of comprehensive characterization of the key elements of the OSMS, a NOM-like high-precision granite gantry system with air-bearing translation and a custom-made precision air-bearing stage for tilting and flipping the surface under test. We show that the high performance of the gantry system allows implementing an original scanning mode for 2D mapping. We demonstrate the efficiency of the developed 2D mapping via comparison with 1D slope measurements performed with the same hyperbolic test mirror using the ALS developmental long trace profiler. The details of the OSMS design and the developed measuring techniques are also provided.

The on-line characterization of a radium slurry by gamma-ray spectrometry.

PubMed

Philips, S; Croft, S

2005-01-01

We have developed an in-line monitor to directly measure the (226)Ra concentration in a nuclear waste stream using quantitative gamma-ray spectrometry applied to the 186keV emission. The waste stream is in the form of a slurry composed of the solid waste material mixed with water. The concentration measurement includes a self-attenuation correction factor determined from a transmission measurement using the 122keV gamma from (57)Co. Presented here is the model for the measurement system and results from some initial tests.

The upgrade system of BESIII ETOF with MRPC technology

NASA Astrophysics Data System (ADS)

Wang, X. Z.; Sun, Y. J.; Li, C.; Heng, Y. K.; Wu, Z.; Cao, P.; Dai, H. L.; Ji, X. L.; Gong, W. X.; Liu, Z.; Luo, X. L.; Sun, W. J.; Wang, S. Y.; Wang, Y.; Yang, R. X.; Ye, M.; Zhao, J. L.

2016-08-01

An upgrade, based on Multigap Resistive Plate Chamber (MRPC) technology, of the endcap Time-Of-Flight (ETOF) detector of the Beijing Spectrometer III (BESIII) has been proposed for the replacement of the current scintillator + PMT based ETOF, with the aim of improving the time resolution down to 80 ps sigma. This improvement will enhance the particle identification capability to meet the higher precision requirements of physics. The ETOF system including MRPC modules, Front End Electronics (FEE), CLOCK module, fast control boards and Time to Digital modules (TDIG), has been designed, constructed and parts of the ETOF system have seperately tested. Aiming at examining the quality of entire ETOF system and training the operation of all participated instruments, a cosmic ray test system was built and tested in the laboratory for about three months to guarantee the performance. In this paper the results of the test are presented indicating that the entire ETOF system works well and satisfies the requirements of the upgrade.

Development of optics for x-ray phase-contrast imaging of high energy density plasmas.

PubMed

Stutman, D; Finkenthal, M; Moldovan, N

2010-10-01

Phase-contrast or refraction-enhanced x-ray radiography can be useful for the diagnostic of low-Z high energy density plasmas, such as imploding inertial confinement fusion (ICF) pellets, due to its sensitivity to density gradients. To separate and quantify the absorption and refraction contributions to x-ray images, methods based on microperiodic optics, such as shearing interferometry, can be used. To enable applying such methods with the energetic x rays needed for ICF radiography, we investigate a new type of optics consisting of grazing incidence microperiodic mirrors. Using such mirrors, efficient phase-contrast imaging systems could be built for energies up to ∼100 keV. In addition, a simple lithographic method is proposed for the production of the microperiodic x-ray mirrors based on the difference in the total reflection between a low-Z substrate and a high-Z film. Prototype mirrors fabricated with this method show promising characteristics in laboratory tests.

Acoustic Injectors for Drop-On-Demand Serial Femtosecond Crystallography.

PubMed

Roessler, Christian G; Agarwal, Rakhi; Allaire, Marc; Alonso-Mori, Roberto; Andi, Babak; Bachega, José F R; Bommer, Martin; Brewster, Aaron S; Browne, Michael C; Chatterjee, Ruchira; Cho, Eunsun; Cohen, Aina E; Cowan, Matthew; Datwani, Sammy; Davidson, Victor L; Defever, Jim; Eaton, Brent; Ellson, Richard; Feng, Yiping; Ghislain, Lucien P; Glownia, James M; Han, Guangye; Hattne, Johan; Hellmich, Julia; Héroux, Annie; Ibrahim, Mohamed; Kern, Jan; Kuczewski, Anthony; Lemke, Henrik T; Liu, Pinghua; Majlof, Lars; McClintock, William M; Myers, Stuart; Nelsen, Silke; Olechno, Joe; Orville, Allen M; Sauter, Nicholas K; Soares, Alexei S; Soltis, S Michael; Song, Heng; Stearns, Richard G; Tran, Rosalie; Tsai, Yingssu; Uervirojnangkoorn, Monarin; Wilmot, Carrie M; Yachandra, Vittal; Yano, Junko; Yukl, Erik T; Zhu, Diling; Zouni, Athina

2016-04-05

X-ray free-electron lasers (XFELs) provide very intense X-ray pulses suitable for macromolecular crystallography. Each X-ray pulse typically lasts for tens of femtoseconds and the interval between pulses is many orders of magnitude longer. Here we describe two novel acoustic injection systems that use focused sound waves to eject picoliter to nanoliter crystal-containing droplets out of microplates and into the X-ray pulse from which diffraction data are collected. The on-demand droplet delivery is synchronized to the XFEL pulse scheme, resulting in X-ray pulses intersecting up to 88% of the droplets. We tested several types of samples in a range of crystallization conditions, wherein the overall crystal hit ratio (e.g., fraction of images with observable diffraction patterns) is a function of the microcrystal slurry concentration. We report crystal structures from lysozyme, thermolysin, and stachydrine demethylase (Stc2). Additional samples were screened to demonstrate that these methods can be applied to rare samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

Near-edge x-ray absorption fine structure spectroscopy at atmospheric pressure with a table-top laser-induced soft x-ray source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kühl, Frank-Christian, E-mail: Frank-christian.kuehl@mail.de; Müller, Matthias, E-mail: matthias.mueller@llg-ev.de; Schellhorn, Meike

2016-07-15

The authors present a table-top soft x-ray absorption spectrometer, accomplishing investigations of the near-edge x-ray absorption fine structure (NEXAFS) in a laboratory environment. The system is based on a low debris plasma ignited by a picosecond laser in a pulsed krypton gas jet, emitting soft x-ray radiation in the range from 1 to 5 nm. For absorption spectroscopy in and around the “water window” (2.3–4.4 nm), a compact helium purged sample compartment for experiments at atmospheric pressure has been constructed and tested. NEXAFS measurements on CaCl{sub 2} and KMnO{sub 4} samples were conducted at the calcium and manganese L-edges, as well asmore » at the oxygen K-edge in air, atmospheric helium, and under vacuum, respectively. The results indicate the importance of atmospheric conditions for an investigation of sample hydration processes.« less

Nanometer-scale characterization of laser-driven compression, shocks, and phase transitions, by x-ray scattering using free electron lasers

DOE PAGES

Kluge, T.; Rödel, C.; Rödel, M.; ...

2017-10-23

In this paper, we study the feasibility of using small angle X-ray scattering (SAXS) as a new experimental diagnostic for intense laser-solid interactions. By using X-ray pulses from a hard X-ray free electron laser, we can simultaneously achieve nanometer and femtosecond resolution of laser-driven samples. This is an important new capability for the Helmholtz international beamline for extreme fields at the high energy density endstation currently built at the European X-ray free electron laser. We review the relevant SAXS theory and its application to transient processes in solid density plasmas and report on first experimental results that confirm the feasibilitymore » of the method. Finally, we present results of two test experiments where the first experiment employs ultra-short laser pulses for studying relativistic laser plasma interactions, and the second one focuses on shock compression studies with a nanosecond laser system.« less

Tetrahedral hydrocarbon nanoparticles in space: X-ray spectra

NASA Astrophysics Data System (ADS)

Bilalbegović, G.; Maksimović, A.; Valencic, L. A.

2018-06-01

It has been proposed, or confirmed, that diamond nanoparticles exist in various environments in space: close to active galactic nuclei, in the vicinity of supernovae and pulsars, in the interior of several planets in the Solar system, in carbon planets, and other exoplanets, carbon-rich stars, meteorites, in X-ray active Herbig Ae/Be stars, and in the interstellar medium. Using density functional theory methods, we calculate the carbon K-edge X-ray absorption spectrum of two large tetrahedral nanodiamonds: C26H32 and C51H52. We also study and test our methods on the astrophysical molecule CH4, the smallest C-H tetrahedral structure. A possible detection of nanodiamonds from X-ray spectra by future telescopes, such as the project Arcus, is proposed. Simulated spectra of the diffuse interstellar medium using Cyg X-2 as a source show that nanodiamonds studied in this work can be detected by Arcus, a high-resolution X-ray spectrometer mission selected by NASA for a Phase A concept study.

Nanometer-scale characterization of laser-driven compression, shocks, and phase transitions, by x-ray scattering using free electron lasers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kluge, T.; Rödel, C.; Rödel, M.

In this paper, we study the feasibility of using small angle X-ray scattering (SAXS) as a new experimental diagnostic for intense laser-solid interactions. By using X-ray pulses from a hard X-ray free electron laser, we can simultaneously achieve nanometer and femtosecond resolution of laser-driven samples. This is an important new capability for the Helmholtz international beamline for extreme fields at the high energy density endstation currently built at the European X-ray free electron laser. We review the relevant SAXS theory and its application to transient processes in solid density plasmas and report on first experimental results that confirm the feasibilitymore » of the method. Finally, we present results of two test experiments where the first experiment employs ultra-short laser pulses for studying relativistic laser plasma interactions, and the second one focuses on shock compression studies with a nanosecond laser system.« less

Acoustic Injectors for Drop-On-Demand Serial Femtosecond Crystallography

DOE PAGES

Roessler, Christian G.; Agarwal, Rakhi; Allaire, Marc; ...

2016-03-17

X-ray free-electron lasers (XFELs) provide very intense X-ray pulses suitable for macromolecular crystallography. Each X-ray pulse typically lasts for tens of femtoseconds and the interval between pulses is many orders of magnitude longer. Here we describe two novel acoustic injection systems that use focused sound waves to eject picoliter to nanoliter crystal-containing droplets out of microplates and into the X-ray pulse from which diffraction data are collected. The on-demand droplet delivery is synchronized to the XFEL pulse scheme, resulting in X-ray pulses intersecting up to 88% of the droplets. We tested several types of samples in a range of crystallizationmore » conditions, wherein the overall crystal hit ratio (e.g., fraction of images with observable diffraction patterns) is a function of the microcrystal slurry concentration. Lastly, we report crystal structures from lysozyme, thermolysin, and stachydrine demethylase (Stc2). In addition, samples were screened to demonstrate that these methods can be applied to rare samples« less

Acoustic Injectors for Drop-On-Demand Serial Femtosecond Crystallography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roessler, Christian G.; Agarwal, Rakhi; Allaire, Marc

X-ray free-electron lasers (XFELs) provide very intense X-ray pulses suitable for macromolecular crystallography. Each X-ray pulse typically lasts for tens of femtoseconds and the interval between pulses is many orders of magnitude longer. Here we describe two novel acoustic injection systems that use focused sound waves to eject picoliter to nanoliter crystal-containing droplets out of microplates and into the X-ray pulse from which diffraction data are collected. The on-demand droplet delivery is synchronized to the XFEL pulse scheme, resulting in X-ray pulses intersecting up to 88% of the droplets. We tested several types of samples in a range of crystallizationmore » conditions, wherein the overall crystal hit ratio (e.g., fraction of images with observable diffraction patterns) is a function of the microcrystal slurry concentration. We report crystal structures from lysozyme, thermolysin, and stachydrine demethylase (Stc2). Additional samples were screened to demonstrate that these methods can be applied to rare samples.« less

Acoustic Injectors for Drop-On-Demand Serial Femtosecond Crystallography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roessler, Christian G.; Agarwal, Rakhi; Allaire, Marc

X-ray free-electron lasers (XFELs) provide very intense X-ray pulses suitable for macromolecular crystallography. Each X-ray pulse typically lasts for tens of femtoseconds and the interval between pulses is many orders of magnitude longer. Here we describe two novel acoustic injection systems that use focused sound waves to eject picoliter to nanoliter crystal-containing droplets out of microplates and into the X-ray pulse from which diffraction data are collected. The on-demand droplet delivery is synchronized to the XFEL pulse scheme, resulting in X-ray pulses intersecting up to 88% of the droplets. We tested several types of samples in a range of crystallizationmore » conditions, wherein the overall crystal hit ratio (e.g., fraction of images with observable diffraction patterns) is a function of the microcrystal slurry concentration. Lastly, we report crystal structures from lysozyme, thermolysin, and stachydrine demethylase (Stc2). In addition, samples were screened to demonstrate that these methods can be applied to rare samples« less

Photon attenuation and neutron moderation correction factors for the inspection of cargo containers with tagged neutrons

NASA Astrophysics Data System (ADS)

Carasco, C.; Perot, B.; Viesti, G.; Valkovic, V.; Sudac, D.; Bernard, S.; Mariani, A.; Szabo, J.-L.; Sannie, G.; Lunardon, M.; Bottosso, C.; Moretto, S.; Pesente, S.; Peerani, P.; Sequeira, V.; Salvato, M.

2007-11-01

The EURopean Illicit TRAfficking Countermeasures Kit (EURITRACK) inspection system uses 14 MeV neutrons produced by the D(T,n α) reaction to detect explosives in cargo containers. Fast-neutron-induced reactions inside the container produce gamma rays, which are detected in coincidence with the associated alpha particle. The definition of the neutron path and the time-of-flight measurement allow positioning the source of the gamma ray inside the container, while the chemical composition of the target material is correlated with the energy spectrum of the coincident gamma rays. However, in case of dense cargo, neutron moderation and photon attenuation inside the container make difficult the reconstruction of the material composition from the measured gamma-ray energy spectrum. An analytical method has been developed and validated against experimental data, which allows obtaining the chemical carbon-to-oxygen and carbon-to-nitrogen ratios of the inspected items from the gamma-ray energy spectra. The principle of the method is presented along with validation tests.

Glass sample preparation and performance investigations. [solar x-ray imager

NASA Technical Reports Server (NTRS)

Johnson, R. Barry

1992-01-01

This final report details the work performed under this delivery order from April 1991 through April 1992. The currently available capabilities for integrated optical performance modeling at MSFC for large and complex systems such as AXAF were investigated. The Integrated Structural Modeling (ISM) program developed by Boeing for the U.S. Air Force was obtained and installed on two DECstations 5000 at MSFC. The structural, thermal and optical analysis programs available in ISM were evaluated. As part of the optomechanical engineering activities, technical support was provided in the design of support structure, mirror assembly, filter wheel assembly and material selection for the Solar X-ray Imager (SXI) program. As part of the fabrication activities, a large number of zerodur glass samples were prepared in different sizes and shapes for acid etching, coating and polishing experiments to characterize the subsurface damage and stresses produced by the grinding and polishing operations. Various optical components for AXAF video microscope and the x-ray test facility were also fabricated. A number of glass fabrication and test instruments such as a scatter plate interferometer, a gravity feed saw and some phenolic cutting blades were fabricated, integrated and tested.

Resolution of x-ray parabolic compound refractive diamond lens defined at the home laboratory

NASA Astrophysics Data System (ADS)

Polyakov, S. N.; Zholudev, S. I.; Gasilov, S. V.; Martyushov, S. Yu.; Denisov, V. N.; Terentiev, S. A.; Blank, V. D.

2017-05-01

Here we demonstrate performance of an original lab system designed for testing of X-ray parabolic compound refractive lenses (CRL) manufactured from a high-quality single-crystalline synthetic diamond grown by the high-pressure hightemperature technique. The basic parameters of a diamond CRL comprised from 28 plano-concave lenses such as the focal length of 634 mm, transmissivity of 0.36, field of view of 1 mm and resolution of 6 µm have been determined. Usually such measurements are performed on synchrotron radiation facilities. In this work characterization of CRL was performed by means of instruments and components that are available for laboratories such as the Rigaku 9kW rotating anode X-ray generator, the PANalytical parallel beam X-ray mirror, a 6 m long optical bench, high precision multi-axis goniometers, high resolution X-ray emulsion films, and ultra-fast high-sensitive X-ray area detector PIXel3D. Developed setup was used to find differences between experimental and design parameters, which is very important for the improvement of CRLs manufacturing technology.

Development and irradiation test of lost alpha detection system for ITER.

PubMed

Nishiura, M; Nagasaka, T; Fujioka, K; Fujimoto, Y; Tanaka, T; Ido, T; Yamamoto, S; Kashiwa, S; Sasao, M

2010-10-01

We developed a lost alpha detection system to use in burning plasma experiments. The scintillators of Ag:ZnS and polycrystalline Ce:YAG were designed for a high-temperature environment, and the optical transmission line was designed to transmit from the scintillator to the port plug. The required optical components of lenses and mirrors were irradiated using the fission reactor with the initial result that there was no clear change after the irradiation with a neutron flux of 9.6×10(17) nm(-2)  s(-1) for 48 h. We propose a diagnostic of alpha particle loss, so-called alpha particle induced gamma ray spectroscopy. The initial laboratory test has been carried out by the use of the Ce doped Lu(2)SiO(5) scintillator detector and an Am-Be source to detect the 4.44 MeV high energy gamma ray due to the (9)Be(α,nγ)(12)C reaction.

AXAF-1 high-resolution mirror assembly image model and comparison with x-ray ground-test image

NASA Astrophysics Data System (ADS)

Zissa, David E.

1999-09-01

The completed High Resolution Mirror Assembly (HRMA) of the Advanced X-ray Astrophysics Facility - Imaging (AXAF-I) was tested at the X-ray Calibration Facility (XRCF) at the NASA- Marshall Space Flight Center (MSFC) in 1997. The MSFC image model was developed during the development of AXAF-I. The MSFC model is a detailed ray-trace model of the as-built HRMA optics and the XRCF teste conditions. The image encircled-energy distributions from the model are found to general agree well with XRCF test data nd the preliminary Smithsonian Astrophysical Observatory (SAO) model. MSFC model effective-area result generally agree with those of the preliminary SAO model. Preliminary model effective-area results were reported by SAO to be approximately 5-13 percent above initial XRCF test results. The XRCF test conditions are removed from the MSFC ray-trace model to derive an on-orbit prediction of the HRMA image.

Advanced X-Ray Telescope Mirrors Provide Sharpest Focus Ever

NASA Astrophysics Data System (ADS)

1997-03-01

Performing beyond expectations, the high- resolution mirrors for NASA's most powerful orbiting X-ray telescope have successfully completed initial testing at Marshall Space Flight Center's X-ray Calibration Facility, Huntsville, AL. "We have the first ground test images ever generated by the telescope's mirror assembly, and they are as good as -- or better than -- expected," said Dr. Martin Weisskopf, Marshall's chief scientist for NASA's Advanced X-ray Astrophysics Facility (AXAF). The mirror assembly, four pairs of precisely shaped and aligned cylindrical mirrors, will form the heart of NASA's third great observatory. The X-ray telescope produces an image by directing incoming X-rays to detectors at a focal point some 30 feet beyond the telescope's mirrors. The greater the percentage of X-rays brought to focus and the smaller the size of the focal spot, the sharper the image. Tests show that on orbit, the mirror assembly of the Advanced X-ray Astrophysics Facility will be able to focus approximately 70 percent of X-rays from a source to a spot less than one-half arc second in radius. The telescope's resolution is equivalent to being able to read the text of a newspaper from half a mile away. "The telescope's focus is very clear, very sharp," said Weisskopf. "It will be able to show us details of very distant sources that we know are out there, but haven't been able to see clearly." In comparison, previous X-ray telescopes -- Einstein and Rosat -- were only capable of focusing X- rays to five arc seconds. The Advanced X-ray Telescope's resolving power is ten times greater. "Images from the new telescope will allow us to make major advances toward understanding how exploding stars create and disperse many of the elements necessary for new solar systems and for life itself," said Dr. Harvey Tananbaum, director of the Advanced X- ray Astrophysics Facility Science Center at the Smithsonian Astrophysical Observatory, in Cambridge, MA -- responsible for the telescope's science mission. "We will observe X-rays generated when stars are torn apart by the incredibly strong gravity around massive black holes in the centers of galaxies," added Tananbaum. On a larger scale, the telescope will play a vital role in answering fundamental questions about the universe. "The superior quality of the mirrors will allow us to see and measure the details of hot gas clouds in clusters of galaxies, giving us a much better idea of the age and size of the universe," said Dr. Leon Van Speybroeck, Telescope Scientist at the Smithsonian Observatory. "These same observations also will measure the amount of dark matter present, providing unique insight into one of nature's great puzzles," said Van Speybroeck. A second phase of testing is now underway at Marshall. Calibration of the observatory's science instruments began in mid-February. "This phase of testing," said Weisskopf, "includes two focal plane instruments and two sets of gratings used to analyze images and energy distributions from cosmic sources seen by the telescope." Working around the clock, test teams are taking measurements and studying results. "It is very exciting," said Weisskopf. "With more than 1,200 measurements taken, there is already a tremendous amount of information for study." The calibration process will end around late April. The mirror assembly then will be shipped to TRW Space and Electronics Group, Redondo Beach, CA -- NASA's prime contractor for the program -- for integration into the spacecraft. The science instruments will remain at Marshall for several more weeks of testing before being shipped to Ball Aerospace and Technologies Corporation in Boulder, CO, where they will be integrated into the science instrument module before being shipped to TRW. The Advanced X-ray Astrophysics Facility is scheduled for launch in August 1998 and will join NASA's Hubble Space Telescope and Compton Gamma-ray Observatory in exploring the universe. Marshall manages development of the observatory for the Office of Space Science, NASA Headquarters, Washington, DC. Using glass purchased from Schott Glaswerke, Mainz, Germany, the telescope's mirrors were built by Hughes Danbury Optical Systems, Danbury, CT. The mirrors were coated by Optical Coating Laboratory, Inc., Santa Rosa, CA; and assembled by Eastman-Kodak Company, Rochester, NY. The AXAF CCD Imaging Spectrometer instrument was developed by Pennsylvania State University, University Park, and the Massachusetts Institute of Technology (MIT), Cambridge, MA. One of the two gratings was developed by MIT. The other was developed by the Space Research Organization Netherlands, Utrecht, Netherlands, in collaboration with the Max Planck Institute, Garching, Germany. The High Resolution Camera instrument was built by the Smithsonian Astrophysical Observatory. Note to editors: Digital images to accompany this release are available via the World Wide Web at the following URL: http://chandra.harvard.edu/press/images.html A photograph is available from the NASA Headquarters Audio Imaging Branch to news media to illustrate this story. The Photograph number is 97-HC-138. Photographs also are available from the Marshall Public Affairs office at 205/544-0034.

Observation of dose-rate dependence in a Fricke dosimeter irradiated at low dose rates with monoenergetic X-rays.

PubMed

O'Leary, Mel; Boscolo, Daria; Breslin, Nicole; Brown, Jeremy M C; Dolbnya, Igor P; Emerson, Chris; Figueira, Catarina; Fox, Oliver J L; Grimes, David Robert; Ivosev, Vladimir; Kleppe, Annette K; McCulloch, Aaron; Pape, Ian; Polin, Chris; Wardlow, Nathan; Currell, Fred J

2018-03-16

Absolute measurements of the radiolytic yield of Fe3+ in a ferrous sulphate dosimeter formulation (6 mM Fe2+), with a 20 keV x-ray monoenergetic beam, are reported. Dose-rate suppression of the radiolytic yield was observed at dose rates lower than and different in nature to those previously reported with x-rays. We present evidence that this effect is most likely to be due to recombination of free radicals radiolytically produced from water. The method used to make these measurements is also new and it provides radiolytic yields which are directly traceable to the SI standards system. The data presented provides new and exacting tests of radiation chemistry codes.

The GAMCIT gamma ray burst detector

NASA Technical Reports Server (NTRS)

Mccall, Benjamin J.; Grunsfeld, John M.; Sobajic, Srdjan D.; Chang, Chinley Leonard; Krum, David M.; Ratner, Albert; Trittschuh, Jennifer E.

1993-01-01

The GAMCIT payload is a Get-Away-Special payload designed to search for high-energy gamma-ray bursts and any associated optical transients. This paper presents details on the design of the GAMCIT payload, in the areas of battery selection, power processing, electronics design, gamma-ray detection systems, and the optical imaging of the transients. The paper discusses the progress of the construction, testing, and specific design details of the payload. In addition, this paper discusses the unique challenges involved in bringing this payload to completion, as the project has been designed, constructed, and managed entirely by undergraduate students. Our experience will certainly be valuable to other student groups interested in taking on a challenging project such as a Get-Away-Special payload.

Systematic and Performance Tests of the Hard X-ray Polarimeter X-Calibur

NASA Astrophysics Data System (ADS)

Endsley, Ryan; Beilicke, Matthias; Kislat, Fabian; Krawczynski, Henric; X-Calibur/InFOCuS

2015-01-01

X-ray polarimetry has great potential to reveal new astrophysical information about the emission processes of high energy sources such as black hole environments, X-ray binary systems, and active galactic nuclei. Here we present the results and conclusions of systematic and performance measurements of the hard X-ray polarimeter, X-Calibur. Designed to be flown on a balloon-borne X-ray telescope, X-Calibur will achieve unprecedented sensitivity and makes use of the fact that polarized X-rays preferentially Compton-scatter perpendicular to their E-field vector. Extensive laboratory measurements taken at Washington University and the Cornell High-Energy Synchrotron Source (CHESS) indicate that X-Calibur combines a detection efficiency on the order of unity with a high modulation factor of µ ≈ 0.5 averaged over the whole detector assembly, and with values up to µ ≈ 0.7 for select subsections of the polarimeter. Additionally, we are able to suppress background flux by more than two orders of magnitude by utilizing an active shield and scintillator coincidence. Comparing laboratory data with Monte Carlo simulations of both polarized and unpolarized hard X-ray beams illustrate that we have an exceptional understanding of the detector response.

Chandra Observations of the Eclipsing Wolf-Rayet Binary CQ CepOver a Full Orbital Cycle

NASA Astrophysics Data System (ADS)

Skinner, Steve L.; Guedel, Manuel; Schmutz, Werner; Zhekov, Svetozar

2018-06-01

We present results of Chandra X-ray observations and simultaneous optical light curves of the short-period (1.64 d) eclipsing WN6+O9 binary system CQ Cep obtained in 2013 and 2017 covering a full binary orbit. Our primary objective was to compare the observed X-ray properties with colliding wind shock theory, which predicts that the hottest shock plasma (T > 20 MK) will form on or near the line-of-centers between the stars. Thus, X-ray variability is expected during eclipses when the hottest plasma is occulted. The X-ray spectrum is strikingly similar to apparently single WN6 stars such as WR 134 and spectral lines reveal plasma over a broad range of temperatures T ~ 4 - 40 MK. Both primary and secondary optical eclipses were clearly detected and provide an accurate orbital period determination (P = 1.6412 d). The X-ray emission remained remarkably steady throughout the orbit and statistical tests give a low probability of variability. The lack of significant X-ray variabililty during eclipses indicates that the X-ray emission is not confined along the line-of-centers but is extended on larger spatial scales, contrary to colliding wind predictions.

New Worlds / New Horizons Science with an X-ray Astrophysics Probe

NASA Technical Reports Server (NTRS)

Smith, Randall K.; Bookbinder, Jay A.; Hornschemeier, Ann E.; Bandler, Simon; Brandt, W. N.; Hughes, John P.; McCammon, Dan; Matsumoto, Hironori; Mushotzky, Richard; Osten, Rachel A.;

Development of all-solid-state flash x-ray generator with photoconductive semiconductor switches.

PubMed

Xun, Ma; Jianjun, Deng; Hongwei, Liu; Jianqiang, Yuan; Jinfeng, Liu; Bing, Wei; Yanling, Qing; Wenhui, Han; Lingyun, Wang; Pin, Jiang; Hongtao, Li

2014-09-01

A compact, low-jitter, and high repetitive rate all-solid-state flash x-ray generator making use of photo conductive semiconductor switches was developed recently for the diagnostic purpose of some hydrokinetical experiments. The generator consisted of twelve stages of Blumlein pulse forming networks, and an industrial cold cathode diode was used to generate intense x-ray radiations with photon energy up to 220 keV. Test experiments showed that the generator could produce >1 kA electron beam currents and x-ray pulses with ~40 ns duration under 100 Hz repetitive rates at least (limited by the triggering laser on hand), also found was that the delay time of the cathode explosive emission is crucial to the energy transfer efficiency of the whole system. In addition, factors affecting the diode impedance, how the switching synchronization and diode impedance determining the allowable operation voltage were discussed.

Development and Testing of the Positron Identification By Coincident Annihilation Photons (PICAP) System

NASA Astrophysics Data System (ADS)

Tran, D.; Connell, J. J.; Lopate, C.; Bickford, B.

2014-12-01

Moderate energy positrons (~few to 10 MeV) have seldom been observed in the Heliosphere, due primarily to there not having been dedicated instruments for such measurements. Their detection would have implications in the study of Solar energetic particle events and the transport and modulation of the Solar wind and Galactic cosmic rays. The Positron Identification by Coincident Annihilation Photons (PICAP) system is designed specifically to measure these moderate energy positrons by simultaneously detecting the two 511-keV γ-ray photons that result from a positron stopping in the instrument and the subsequent electron-positron annihilation. This method is also expected to effectively discriminate positrons from protons by measuring the amount of energy deposited in the detectors (dE/dx versus residual energy). PICAP offers a low-mass, low-power option for measuring positrons, electrons, and ions in space. Following Monte Carlo modeling, a PICAP laboratory prototype, adaptable to a space-flight design, was designed, built, and tested. This instrument is comprised of (Si) solid-state detectors, plastic scintillation detectors, and high-Z BGO crystal scintillator suitable for detecting the 511-keV γ rays. The prototype underwent preliminary laboratory testing and calibration using radioactive sources for the purpose of establishing functionality. It has since been exposed to beams of energetic protons (up to ~200 MeV) at Massachusetts General Hospital's Francis H. Burr Proton Beam Therapy Center and positrons and electrons (up to ~10 MeV) at Idaho State University's Idaho Accelerator Center. The goal is to validate modeling and determine the performance of the instrument concept. We will present a summary of modeling calculations and analysis of data taken at the accelerator tests. This work is 95% supported by NASA Grant NNX10AC10G.

First attempt of at-cavity cryogenic X-ray detection in a CEBAF cryomodule for field emission monitoring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geng, Rongli; Daly, Edward; Drury, Michael

2015-09-01

We report on the first result of at-cavity X-ray detection in a CEBAF cryomodule for field emission monitoring. In the 8-cavity cryomodule F100, two silicon diodes were installed near the end flange of each cavity. Each cavity was individually tested during the cryomodule test in JLab’s cryomodule test facility. The behaviors of these at-cavity cryogenic X-ray detectors were compared with those of the standard ‘in air’ Geiger-Muller (G-M) tubes. Our initial experiments establish correlation between X-ray response of near diodes and the field emission source cavity in the 8-cavity string. For two out of these eight cavities, we also carriedmore » out at-cavity X-ray detection experiment during their vertical testing. The aim is to track field emission behavior uniquely from vertical cavity testing to horizontal cavity testing in the cryomodule. These preliminary results confirmed our expectation and warrant further effort toward the establishment of permanent at-cavity cryogenic X-ray detection for SRF development and operation.« less

In-orbit performance of a helium dewar for the soft X-ray spectrometer onboard ASTRO-H

NASA Astrophysics Data System (ADS)

Yoshida, Seiji; Miyaoka, Mikio; Kanao, Ken'ichi; Tsunematsu, Shoji; Otsuka, Kiyomi; Hoshika, Shunji; Narasaki, Katsuhiro; Mitsuda, Kazuhisa; Yamasaki, Noriko; Takei, Yoh; Fujimoto, Ryuichi; Ezoe, Yuichiro; Sato, Yoichi; Okamoto, Atsushi; Noda, Hirofumi; DiPirro, Michael; Shirron, Peter

2018-04-01

ASTRO-H was an X-ray astronomy satellite that the Japan Aerospace Exploration Agency (JAXA) developed to study the evolution of the universe and physical phenomena yet to be discovered. The primary scientific instrument of ASTRO-H was the Soft X-ray Spectrometer (SXS). Its detectors were to be cooled to 50 m K using a complex cryogenic system with a multistage adiabatic demagnetization refrigerator (ADR) developed by the National Aeronautics and Space Administration (NASA), and a cryogenic system developed by Sumitomo Heavy Industries, Ltd. (SHI). SHI's cryogenic system was required to cool the ADR's heatsink to 1.3 K or less in orbit for three years or longer. To meet these requirements, SHI developed a hybrid cryogenic system consisting of a liquid helium tank, a 4 K Joule-Thomson cooler, and two two-stage Stirling coolers. ASTRO-H was launched from Tanegashima Space Center on February 17, 2016. The initial operation of the SXS cryogenic system in orbit was completed successfully. The cooling performance was as expected and could have exceeded the lifetime requirement of three years. This paper describes results of ground tests, results of top-off filling of superfluid liquid helium just before launch, and cooling performance in orbit.

Non-null annular subaperture stitching interferometry for aspheric test

NASA Astrophysics Data System (ADS)

Zhang, Lei; Liu, Dong; Shi, Tu; Yang, Yongying; Chong, Shiyao; Miao, Liang; Huang, Wei; Shen, Yibing; Bai, Jian

2015-10-01

A non-null annular subaperture stitching interferometry (NASSI), combining the subaperture stitching idea and non-null test method, is proposed for steep aspheric testing. Compared with standard annular subaperture stitching interferometry (ASSI), a partial null lens (PNL) is employed as an alternative to the transmission sphere, to generate different aspherical wavefronts as the references. The coverage subaperture number would thus be reduced greatly for the better performance of aspherical wavefronts in matching the local slope of aspheric surfaces. Instead of various mathematical stitching algorithms, a simultaneous reverse optimizing reconstruction (SROR) method based on system modeling and ray tracing is proposed for full aperture figure error reconstruction. All the subaperture measurements are simulated simultaneously with a multi-configuration model in a ray-tracing program, including the interferometric system modeling and subaperture misalignments modeling. With the multi-configuration model, full aperture figure error would be extracted in form of Zernike polynomials from subapertures wavefront data by the SROR method. This method concurrently accomplishes subaperture retrace error and misalignment correction, requiring neither complex mathematical algorithms nor subaperture overlaps. A numerical simulation exhibits the comparison of the performance of the NASSI and standard ASSI, which demonstrates the high accuracy of the NASSI in testing steep aspheric. Experimental results of NASSI are shown to be in good agreement with that of Zygo® VerifireTM Asphere interferometer.

An alpha–gamma coincidence spectrometer based on the Photon–Electron Rejecting Alpha Liquid Scintillation (PERALS®) system

DOE PAGES

Cadieux, J. R.; Fugate, G. A.; King, III, G. S.

2015-02-07

Here, an alpha–gamma coincidence spectrometer has been developed for the measurement of selected actinide isotopes in the presence of high beta/gamma fields. The system is based on a PERALS® liquid scintillation counter for beta/alpha discrimination and was successfully tested with both high purity germanium and bismuth germanate, gamma-ray detectors using conventional analog electronics.

Development of the focal plane PNCCD camera system for the X-ray space telescope eROSITA

NASA Astrophysics Data System (ADS)

Meidinger, Norbert; Andritschke, Robert; Ebermayer, Stefanie; Elbs, Johannes; Hälker, Olaf; Hartmann, Robert; Herrmann, Sven; Kimmel, Nils; Schächner, Gabriele; Schopper, Florian; Soltau, Heike; Strüder, Lothar; Weidenspointner, Georg

2010-12-01

A so-called PNCCD, a special type of CCD, was developed twenty years ago as focal plane detector for the XMM-Newton X-ray astronomy mission of the European Space Agency ESA. Based on this detector concept and taking into account the experience of almost ten years of operation in space, a new X-ray CCD type was designed by the ‘MPI semiconductor laboratory’ for an upcoming X-ray space telescope, called eROSITA (extended Roentgen survey with an imaging telescope array). This space telescope will be equipped with seven X-ray mirror systems of Wolter-I type and seven CCD cameras, placed in their foci. The instrumentation permits the exploration of the X-ray universe in the energy band from 0.3 up to 10 keV by spectroscopic measurements with a time resolution of 50 ms for a full image comprising 384×384 pixels. Main scientific goals are an all-sky survey and investigation of the mysterious ‘Dark Energy’. The eROSITA space telescope, which is developed under the responsibility of the ‘Max-Planck-Institute for extraterrestrial physics’, is a scientific payload on the new Russian satellite ‘Spectrum-Roentgen-Gamma’ (SRG). The mission is already approved by the responsible Russian and German space agencies. After launch in 2012 the destination of the satellite is Lagrange point L2. The planned observational program takes about seven years. We describe the design of the eROSITA camera system and present important test results achieved recently with the eROSITA prototype PNCCD detector. This includes a comparison of the eROSITA detector with the XMM-Newton detector.

Correlation of scanning microwave interferometry and digital X-ray images for damage detection in ceramic composite armor

NASA Astrophysics Data System (ADS)

Schmidt, Karl F.; Goitia, Ryan M.; Ellingson, William A.; Green, William

2012-05-01

Application of non-contact, scanning, microwave interferometry for inspection of ceramic-based composite armor facilitates detection of defects which may occur in manufacturing or in service. Non-contact, one-side access permits inspection of panels while on the vehicle. The method was applied as a base line inspection and post-damage inspection of composite ceramic armor containing artificial defects, fiduciaries, and actual damage. Detection, sizing, and depth location capabilities were compared using microwave interferometry system and micro-focus digital x-ray imaging. The data demonstrates corroboration of microwave interference scanning detection of cracks and laminar features. The authors present details of the system operation, descriptions of the test samples used, and recent results obtained.

[Design and accuracy analysis of upper slicing system of MSCT].

PubMed

Jiang, Rongjian

2013-05-01

The upper slicing system is the main components of the optical system in MSCT. This paper focuses on the design of upper slicing system and its accuracy analysis to improve the accuracy of imaging. The error of slice thickness and ray center by bearings, screw and control system were analyzed and tested. In fact, the accumulated error measured is less than 1 microm, absolute error measured is less than 10 microm. Improving the accuracy of the upper slicing system contributes to the appropriate treatment methods and success rate of treatment.

76 FR 43666 - Privacy Act of 1974; System of Records

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-21

... which result in a contrary determination. ADDRESSES: You may submit comments, identified by docket... test results; Deoxyribonucleic Acid (DNA); dental care eligibility codes and dental x-rays. Patient... to collect any resulting over payment (38 U.S.C. 5304(c)). (2) Providing military personnel and...

Multiwavelength monitoring and X-ray brightening of Be X-ray binary PSR J2032+4127/MT91 213 on its approach to periastron

DOE PAGES

Ho, Wynn C. G.; Ng, C. -Y.; Lyne, Andrew G.; ...

2016-09-22

The radio and gamma-ray pulsar PSR J2032+4127 was recently found to be in a decades-long orbit with the Be star MT91 213, with the pulsar moving rapidly towards periastron. This binary shares many similar characteristics with the previously unique binary system PSR B1259-63/LS 2883. Here in this paper, we describe radio, X-ray, and optical monitoring of PSR J2032+4127/MT91 213. Our extended orbital phase coverage in radio, supplemented with Fermi LAT gamma-ray data, allows us to update and refine the orbital period to 45–50 yr and time of periastron passage to 2017 November. We analyse archival and recent Chandra and Swiftmore » observations and show that PSR J2032+4127/MT91 213 is now brighter in X-rays by a factor of ~70 since 2002 and ~20 since 2010. While the pulsar is still far from periastron, this increase in X-rays is possibly due to collisions between pulsar and Be star winds. Optical observations of the Hα emission line of the Be star suggest that the size of its circumstellar disc may be varying by ~2 over time-scales as short as 1–2 months. In conclusion, multiwavelength monitoring of PSR J2032+4127/MT91 213 will continue through periastron passage, and the system should present an interesting test case and comparison to PSR B1259-63/LS 2883.« less

The PAMELA experiment on satellite and its capability in cosmic rays measurements

NASA Astrophysics Data System (ADS)

Adriani, O.; Ambriola, M.; Barbarino, G.; Barbier, L. M.; Bartalucci, S.; Bazilevskaja, G.; Bellotti, R.; Bertazzoni, S.; Bidoli, V.; Boezio, M.; Bogomolov, E.; Bonechi, L.; Bonvicini, V.; Boscherini, M.; Bravar, U.; Cafagna, F.; Campana, D.; Carlson, P.; Casolino, M.; Castellano, M.; Castellini, G.; Christian, E. R.; Ciacio, F.; Circella, M.; D'Alessandro, R.; De Marzo, C. N.; De Pascale, M. P.; Finetti, N.; Furano, G.; Gabbanini, A.; Galper, A. M.; Giglietto, N.; Grandi, M.; Grigorjeva, A.; Guarino, F.; Hof, M.; Koldashov, S. V.; Korotkov, M. G.; Krizmanic, J. F.; Krutkov, S.; Lund, J.; Marangelli, B.; Marino, L.; Menn, W.; Mikhailov, V. V.; Mirizzi, N.; Mitchell, J. W.; Mocchiutti, E.; Moiseev, A. A.; Morselli, A.; Mukhametshin, R.; Ormes, J. F.; Osteria, G.; Ozerov, J. V.; Papini, P.; Pearce, M.; Perego, A.; Piccardi, S.; Picozza, P.; Ricci, M.; Salsano, A.; Schiavon, P.; Scian, G.; Simon, M.; Sparvoli, R.; Spataro, B.; Spillantini, P.; Spinelli, P.; Stephens, S. A.; Stochaj, S. J.; Stozhkov, Y.; Straulino, S.; Streitmatter, R. E.; Taccetti, F.; Tesi, M.; Vacchi, A.; Vannuccini, E.; Vasiljev, G.; Vignoli, V.; Voronov, S. A.; Yurkin, Y.; Zampa, G.; Zampa, N.

2002-02-01

The PAMELA& equipment will be assembled in 2001 and installed on board the Russian satellite Resurs. PAMELA is conceived mainly to study the antiproton and positron fluxes in cosmic rays up to high energy (190GeV for p¯ and 270GeV for e+) and to search antinuclei, up to 30GeV/n, with a sensitivity of 10-7 in the He/He ratio. The PAMELA telescope consists of: a magnetic spectrometer made up of a permanent magnet system equipped with double sided microstrip silicon detectors; a transition radiation detector made up of active layers of proportional straw tubes interleaved with carbon fibre radiators; and a silicon-tungsten imaging calorimeter made up of layers of tungsten absorbers and silicon detector planes. A time-of-flight system and anti-coincidence counters complete the PAMELA equipment. In the past years, tests have been done on each subdetector of PAMELA; the main results are presented and their implications on the anti-particles identification capability in cosmic rays are discussed here.

The Road to the Common PET/CT Detector

NASA Astrophysics Data System (ADS)

Nassalski, Antoni; Moszynski, Marek; Szczesniak, Tomasz; Wolski, Dariusz; Batsch, Tadeusz

2007-10-01

Growing interest in the development of dual modality positron emission/X-rays tomography (PET/CT) systems prompts researchers to face a new challenge: to acquire both the anatomical and functional information in the same measurement, simultaneously using the same detection system and electronics. The aim of this work was to study a detector consisting of LaBr3, LSO or LYSO pixel crystals coupled to an avalanche photodiode (APD). The measurements covered tests of the detectors in PET and CT modes, respectively. The measurements included the determination of light output, energy resolution, the non-proportionality of the light yield and the time resolution for 511 keV annihilation quanta; analysis also included characterizing the PET detector, and determining the dependence of counting rate versus mean current of the APD in the X-ray detection. In the present experiment, the use of counting and current modes in the CT detection increases the dynamic range of the measured dose of X-rays by a factor of 20, compared to the counting mode alone.

Windowless microfluidic platform based on capillary burst valves for high intensity x-ray measurements.

PubMed

Vig, Asger Laurberg; Haldrup, Kristoffer; Enevoldsen, Nikolaj; Thilsted, Anil Haraksingh; Eriksen, Johan; Kristensen, Anders; Feidenhans'l, Robert; Nielsen, Martin Meedom

2009-11-01

We propose and describe a microfluidic system for high intensity x-ray measurements. The required open access to a microfluidic channel is provided by an out-of-plane capillary burst valve (CBV). The functionality of the out-of-plane CBV is characterized with respect to the diameter of the windowless access hole, ranging from 10 to 130 microm. Maximum driving pressures from 22 to 280 mbar corresponding to refresh rates of the exposed sample from 300 Hz to 54 kHz is demonstrated. The microfluidic system is tested at beamline ID09b at the ESRF synchrotron radiation facility in Grenoble, and x-ray scattering measurements are shown to be feasible and to require only very limited amounts of sample, <1 ml/h of measurements without recapturing of sample. With small adjustments of the present chip design, scattering angles up to 30 degrees can be achieved without shadowing effects and integration on-chip mixing and spectroscopy appears straightforward.

Windowless microfluidic platform based on capillary burst valves for high intensity x-ray measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vig, Asger Laurberg; Enevoldsen, Nikolaj; Thilsted, Anil Haraksingh

2009-11-15

We propose and describe a microfluidic system for high intensity x-ray measurements. The required open access to a microfluidic channel is provided by an out-of-plane capillary burst valve (CBV). The functionality of the out-of-plane CBV is characterized with respect to the diameter of the windowless access hole, ranging from 10 to 130 {mu}m. Maximum driving pressures from 22 to 280 mbar corresponding to refresh rates of the exposed sample from 300 Hz to 54 kHz is demonstrated. The microfluidic system is tested at beamline ID09b at the ESRF synchrotron radiation facility in Grenoble, and x-ray scattering measurements are shown tomore » be feasible and to require only very limited amounts of sample, <1 ml/h of measurements without recapturing of sample. With small adjustments of the present chip design, scattering angles up to 30 deg. can be achieved without shadowing effects and integration on-chip mixing and spectroscopy appears straightforward.« less

Feasibility of in situ beta ray measurements in underwater environment.

PubMed

Park, Hye Min; Park, Ki Hyun; Kang, Sung Won; Joo, Koan Sik

2017-09-01

We describe an attempt at the development of an in situ detector for beta ray measurements in underwater environment. The prototype of the in situ detector is based on a CaF2: Eu scintillator using crystal light guide and Si photomultiplier. Tests were conducted using various reference sources for evaluating the linearity and stability of the detector in underwater environment. The system is simple and stable for long-term monitoring, and consumes low power. We show here an effective detection distance of 7 mm and a 2.273 MeV end-point energy spectrum of 90 Sr/ 90 Y when using the system underwater. The results demonstrate the feasibility of in situ beta ray measurements in underwater environment and can be applied for designing an in situ detector for radioactivity measurement in underwater environment. The in situ detector can also have other applications such as installation on the marine monitoring platform and quantitative analysis of radionuclides. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pink-beam focusing with a one-dimensional compound refractive lens

DOE PAGES

Dufresne, Eric M.; Dunford, Robert W.; Kanter, Elliot P.; ...

2016-07-28

The performance of a cooled Be compound refractive lens (CRL) has been tested at the Advanced Photon Source (APS) to enable vertical focusing of the pink beam and permit the X-ray beam to spatially overlap with an 80 µm-high low-density plasma that simulates astrophysical environments. Focusing the fundamental harmonics of an insertion device white beam increases the APS power density; here, a power density as high as 500 W mm –2 was calculated. A CRL is chromatic so it does not efficiently focus X-rays whose energies are above the fundamental. Only the fundamental of the undulator focuses at the experiment.more » A two-chopper system reduces the power density on the imaging system and lens by four orders of magnitude, enabling imaging of the focal plane without any X-ray filter. As a result, a method to measure such high power density as well as the performance of the lens in focusing the pink beam is reported.« less

Dose-rate plays a significant role in synchrotron radiation X-ray-induced damage of rodent testes.

PubMed

Chen, Heyu; Wang, Ban; Wang, Caixia; Cao, Wei; Zhang, Jie; Ma, Yingxin; Hong, Yunyi; Fu, Shen; Wu, Fan; Ying, Weihai

2016-01-01

Synchrotron radiation (SR) X-ray has significant potential for applications in medical imaging and cancer treatment. However, the mechanisms underlying SR X-ray-induced tissue damage remain unclear. Previous studies on regular X-ray-induced tissue damage have suggested that dose-rate could affect radiation damage. Because SR X-ray has exceedingly high dose-rate compared to regular X-ray, it remains to be determined if dose-rate may affect SR X-ray-induced tissue damage. We used rodent testes as a model to investigate the role of dose-rate in SR X-ray-induced tissue damage. One day after SR X-ray irradiation, we determined the effects of the irradiation of the same dosage at two different dose-rates, 0.11 Gy/s and 1.1 Gy/s, on TUNEL signals, caspase-3 activation and DNA double-strand breaks (DSBs) of the testes. Compared to those produced by the irradiation at 0.11 Gy/s, irradiation at 1.1 Gy/s produced higher levels of DSBs, TUNEL signals, and caspase-3 activation in the testes. Our study has provided the first evidence suggesting that dose-rate could be a significant factor in SR X-ray-induced tissue damage, which may establish a valuable base for utilizing this factor to manipulate the tissue damage in SR X-ray-based medical applications.

Dose-rate plays a significant role in synchrotron radiation X-ray-induced damage of rodent testes

PubMed Central

Chen, Heyu; Wang, Ban; Wang, Caixia; Cao, Wei; Zhang, Jie; Ma, Yingxin; Hong, Yunyi; Fu, Shen; Wu, Fan; Ying, Weihai

2016-01-01

Synchrotron radiation (SR) X-ray has significant potential for applications in medical imaging and cancer treatment. However, the mechanisms underlying SR X-ray-induced tissue damage remain unclear. Previous studies on regular X-ray-induced tissue damage have suggested that dose-rate could affect radiation damage. Because SR X-ray has exceedingly high dose-rate compared to regular X-ray, it remains to be determined if dose-rate may affect SR X-ray-induced tissue damage. We used rodent testes as a model to investigate the role of dose-rate in SR X-ray-induced tissue damage. One day after SR X-ray irradiation, we determined the effects of the irradiation of the same dosage at two different dose-rates, 0.11 Gy/s and 1.1 Gy/s, on TUNEL signals, caspase-3 activation and DNA double-strand breaks (DSBs) of the testes. Compared to those produced by the irradiation at 0.11 Gy/s, irradiation at 1.1 Gy/s produced higher levels of DSBs, TUNEL signals, and caspase-3 activation in the testes. Our study has provided the first evidence suggesting that dose-rate could be a significant factor in SR X-ray-induced tissue damage, which may establish a valuable base for utilizing this factor to manipulate the tissue damage in SR X-ray-based medical applications. PMID:28078052

21 CFR 872.1810 - Intraoral source x-ray system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Intraoral source x-ray system. 872.1810 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1810 Intraoral source x-ray system. (a) Identification. An intraoral source x-ray system is an electrically powered device that produces x-rays and is...

21 CFR 872.1810 - Intraoral source x-ray system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intraoral source x-ray system. 872.1810 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1810 Intraoral source x-ray system. (a) Identification. An intraoral source x-ray system is an electrically powered device that produces x-rays and is...

21 CFR 872.1810 - Intraoral source x-ray system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Intraoral source x-ray system. 872.1810 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1810 Intraoral source x-ray system. (a) Identification. An intraoral source x-ray system is an electrically powered device that produces x-rays and is...

21 CFR 872.1810 - Intraoral source x-ray system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Intraoral source x-ray system. 872.1810 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1810 Intraoral source x-ray system. (a) Identification. An intraoral source x-ray system is an electrically powered device that produces x-rays and is...

Single event test methodology for integrated optoelectronics

NASA Technical Reports Server (NTRS)

Label, Kenneth A.; Cooley, James A.; Stassinopoulos, E. G.; Marshall, Paul; Crabtree, Christina

1993-01-01

A single event upset (SEU), defined as a transient or glitch on the output of a device, and its applicability to integrated optoelectronics are discussed in the context of spacecraft design and the need for more than a bit error rate viewpoint for testing and analysis. A methodology for testing integrated optoelectronic receivers and transmitters for SEUs is presented, focusing on the actual test requirements and system schemes needed for integrated optoelectronic devices. Two main causes of single event effects in the space environment, including protons and galactic cosmic rays, are considered along with ground test facilities for simulating the space environment.

Design and image-quality performance of high resolution CMOS-based X-ray imaging detectors for digital mammography

NASA Astrophysics Data System (ADS)

Cha, B. K.; Kim, J. Y.; Kim, Y. J.; Yun, S.; Cho, G.; Kim, H. K.; Seo, C.-W.; Jeon, S.; Huh, Y.

2012-04-01

In digital X-ray imaging systems, X-ray imaging detectors based on scintillating screens with electronic devices such as charge-coupled devices (CCDs), thin-film transistors (TFT), complementary metal oxide semiconductor (CMOS) flat panel imagers have been introduced for general radiography, dental, mammography and non-destructive testing (NDT) applications. Recently, a large-area CMOS active-pixel sensor (APS) in combination with scintillation films has been widely used in a variety of digital X-ray imaging applications. We employed a scintillator-based CMOS APS image sensor for high-resolution mammography. In this work, both powder-type Gd2O2S:Tb and a columnar structured CsI:Tl scintillation screens with various thicknesses were fabricated and used as materials to convert X-ray into visible light. These scintillating screens were directly coupled to a CMOS flat panel imager with a 25 × 50 mm2 active area and a 48 μm pixel pitch for high spatial resolution acquisition. We used a W/Al mammographic X-ray source with a 30 kVp energy condition. The imaging characterization of the X-ray detector was measured and analyzed in terms of linearity in incident X-ray dose, modulation transfer function (MTF), noise-power spectrum (NPS) and detective quantum efficiency (DQE).

Structural changes of green roof growing substrate layer studied by X-ray CT

NASA Astrophysics Data System (ADS)

Jelinkova, Vladimira; Sacha, Jan; Dohnal, Michal; Snehota, Michal

2017-04-01

Increasing interest in green infrastructure linked with newly implemented legislation/rules/laws worldwide opens up research potential for field of soil hydrology. A better understanding of function of engineered soils involved in green infrastructure solutions such as green roofs or rain garden is needed. A soil layer is considered as a highly significant component of the aforesaid systems. In comparison with a natural soil, the engineered soil is assumed to be the more challenging case due to rapid structure changes early stages after its build-up. The green infrastructure efficiency depends on the physical and chemical properties of the soil, which are, in the case of engineered soils, a function of its initial composition and subsequent soil formation processes. The project presented in this paper is focused on fundamental processes in the relatively thick layer of engineered soil. The initial structure development, during which the pore geometry is altered by the growth of plant roots, water influx, solid particles translocation and other soil formation processes, is investigated with the help of noninvasive imaging technique  X-ray computed tomography. The soil development has been studied on undisturbed soil samples taken periodically from green roof test system during early stages of its life cycle. Two approaches and sample sizes were employed. In the first approach, undisturbed samples (volume of about 63 cm3) were taken each time from the test site and scanned by X-ray CT. In the second approach, samples (volume of about 630 cm3) were permanently installed at the test site and has been repeatedly removed to perform X-ray CT imaging. CT-derived macroporosity profiles reveal significant temporal changes of soil structure. Clogging of pores by fine particles and fissures development are two most significant changes that would affect the green roof system efficiency. This work has been supported by the Ministry of Education, Youth and Sports within National Sustainability Programme I, project number LO1605 and with financial support from the Czech Science Foundation under project number GAČR 17-21011S.

Relieved residual damage in the hematopoietic system of mice rescued by radiation-induced adaptive response (Yonezawa Effect)

PubMed Central

Wang, Bing; Tanaka, Kaoru; Ninomiya, Yasuharu; Maruyama, Kouichi; VarèS, Guillaume; Eguchi-Kasai, Kiyomi; Nenoi, Mitsuru

2013-01-01

Existence of adaptive response (AR) was previously demonstrated in C57BL/6J mice. Irradiations were performed by delivering a priming low dose of X-rays (0.50 Gy) in combination with a challenge high dose of accelerated carbon or neon ion particles. AR was characterized by significantly decreased mortality in the 30-day survival test. This mouse AR model (‘Yonezawa Effect’) was originally established by using X-rays as both the priming and challenge irradiations. The underlying mechanism was due to radio-resistance occurring in blood-forming tissues. In this study, we verified the existence of AR and further investigated residual damage in the hematopoietic system in surviving animals. Results showed that the priming low dose of X-rays could relieve the detrimental effects on the hematopoietic system. We observed both an improvement in the blood platelet count and the ratio of polychromatic erythrocytes (PCEs) to the sum of PCEs and normochromatic erythrocytes (NCEs) and a marked reduction of the incidences of micronucleated PCEs and micronucleated NCEs. These findings suggest that the priming low dose of low linear energy transfer (LET) X-rays induced a protective effect on the hematopoietic system, which may play an important role in both rescue from acute lethal damage (mouse killing) and prevention of late detrimental consequences (residual anhematopoiesis and delayed genotoxic effects) caused by exposure to a high challenge dose from low-LET (X-ray) or high-LET (carbon and neon ion) irradiations. These findings provide new knowledge of the characterization of the Yonezawa Effect by providing new insight into the mechanistic study of AR in vivo. PMID:22923746

High resolution stationary digital breast tomosynthesis using distributed carbon nanotube x-ray source array.

PubMed

Qian, Xin; Tucker, Andrew; Gidcumb, Emily; Shan, Jing; Yang, Guang; Calderon-Colon, Xiomara; Sultana, Shabana; Lu, Jianping; Zhou, Otto; Spronk, Derrek; Sprenger, Frank; Zhang, Yiheng; Kennedy, Don; Farbizio, Tom; Jing, Zhenxue

2012-04-01

The purpose of this study is to investigate the feasibility of increasing the system spatial resolution and scanning speed of Hologic Selenia Dimensions digital breast tomosynthesis (DBT) scanner by replacing the rotating mammography x-ray tube with a specially designed carbon nanotube (CNT) x-ray source array, which generates all the projection images needed for tomosynthesis reconstruction by electronically activating individual x-ray sources without any mechanical motion. The stationary digital breast tomosynthesis (s-DBT) design aims to (i) increase the system spatial resolution by eliminating image blurring due to x-ray tube motion and (ii) reduce the scanning time. Low spatial resolution and long scanning time are the two main technical limitations of current DBT technology. A CNT x-ray source array was designed and evaluated against a set of targeted system performance parameters. Simulations were performed to determine the maximum anode heat load at the desired focal spot size and to design the electron focusing optics. Field emission current from CNT cathode was measured for an extended period of time to determine the stable life time of CNT cathode for an expected clinical operation scenario. The source array was manufactured, tested, and integrated with a Selenia scanner. An electronic control unit was developed to interface the source array with the detection system and to scan and regulate x-ray beams. The performance of the s-DBT system was evaluated using physical phantoms. The spatially distributed CNT x-ray source array comprised 31 individually addressable x-ray sources covering a 30 angular span with 1 pitch and an isotropic focal spot size of 0.6 mm at full width at half-maximum. Stable operation at 28 kV(peak) anode voltage and 38 mA tube current was demonstrated with extended lifetime and good source-to-source consistency. For the standard imaging protocol of 15 views over 14, 100 mAs dose, and 2 × 2 detector binning, the projection resolution along the scanning direction increased from 4.0 cycles/mm [at 10% modulation-transfer-function (MTF)] in DBT to 5.1 cycles/mm in s-DBT at magnification factor of 1.08. The improvement is more pronounced for faster scanning speeds, wider angular coverage, and smaller detector pixel sizes. The scanning speed depends on the detector, the number of views, and the imaging dose. With 240 ms detector readout time, the s-DBT system scanning time is 6.3 s for a 15-view, 100 mAs scan regardless of the angular coverage. The scanning speed can be reduced to less than 4 s when detectors become faster. Initial phantom studies showed good quality reconstructed images. A prototype s-DBT scanner has been developed and evaluated by retrofitting the Selenia rotating gantry DBT scanner with a spatially distributed CNT x-ray source array. Preliminary results show that it improves system spatial resolution substantially by eliminating image blur due to x-ray focal spot motion. The scanner speed of s-DBT system is independent of angular coverage and can be increased with faster detector without image degration. The accelerated lifetime measurement demonstrated the long term stability of CNT x-ray source array with typical clinical operation lifetime over 3 years.

RELATIVE EFFECTIVENESS OF 14 Mev NEUTRONS AND 200 KVP X-RAYS FOR PRODUCTION OF LETHALITY IN GRASSHOPPER EMBRYOS. A PRELIMINARY STUDY (thesis)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bicker, A.E.

1962-05-01

A test system using the grasshopper embryo with hatching as the criterion for the end-point was proposed to determine the relative effectiveness of 14 Mev neutrons and 200 kvp x rays. Eggs of Chortophaga (14 day) and Encoptolophus (14 day and terminal) were subjected to various doses of both radiations. Values for the medial lethal doses from the data obtained were 650 rads for Chortophaga, 760 rads for Encoptolophus (14 day), and 1800 rads for Encoptolophus (terminal). The shape of the dose-effect curve relative to x- irradiation survival was assumed to be unchanged so that an estimate of the LD/more » sub 50/ could be made. The value obtained was 370 rads. The RBE of 14 Mev neutrons and 200 kvp x rays on Chortophaga (14 day) embryos was 1.76. It was concluded that Chortophaga and Encoptolophus embryos irradiated in the 14 day development stage with hatching as an end-point constitute valid systems for the measurement of the relative effectiveness of the 14 Mev neutrons and 200 kvp x rays. (P.C.H.)« less

The Focal Plane Assembly for the Athena X-Ray Integral Field Unit Instrument

NASA Technical Reports Server (NTRS)

Jackson, B. D.; Van Weers, H.; van der Kuur, J.; den Hartog, R.; Akamatsu, H.; Argan, A.; Bandler, S. R.; Barbera, M.; Barret, D.; Bruijn, M. P.;

PELAN applications and recent field tests

NASA Astrophysics Data System (ADS)

Martinez, Juan J.; Holslin, Daniel T.

2004-10-01

When neutrons interact with particular nuclei, the resulting energy of the interaction can be released in the form of gamma rays, which are characteristic of the nucleus involved in the reaction. The PELAN (Pulsed Elemental Analysis with Neutrons) system uses a pulsed neutron generator and an integral thermalizing shield that induce reactions that cover most of the entire gamma ray energy spectra1. The neutron generator uses a D-T reaction, which releases fast 14MeV neutrons responsible for providing information on those nuclei that mostly respond to inelastic scattering. During the time period between pulses, the fast neutrons undergo multiple inelastic interactions that lower their energy making them easier to be captured by certain nuclei; this energy spectrum of gamma rays induced by these interactions are designated as the gamma ray thermal spectra. The PELAN system has been used for a number of applications where non-intrusive, non-destructive interrogation is needed. Although Pulsed Fast Thermal Neutron Analysis (PFTNA) has been around for approximately 30 years, the technology has never been successfully commercialized for practical applications. The following report illustrates examples of the performance of on a number of applications of interrogation of Unexploded Ordnance (UXO), mine confirmation, large vehicle bombs inspection and illicit drug smuggling detection.

Rapid limit tests for metal impurities in pharmaceutical materials by X-ray fluorescence spectroscopy using wavelet transform filtering.

PubMed

Arzhantsev, Sergey; Li, Xiang; Kauffman, John F

2011-02-01

We introduce a new method for analysis of X-ray fluorescence (XRF) spectra based on continuous wavelet transform filters, and the method is applied to the determination of toxic metals in pharmaceutical materials using hand-held XRF spectrometers. The method uses the continuous wavelet transform to filter the signal and noise components of the spectrum. We present a limit test that compares the wavelet domain signal-to-noise ratios at the energies of the elements of interest to an empirically determined signal-to-noise decision threshold. The limit test is advantageous because it does not require the user to measure calibration samples prior to measurement, though system suitability tests are still recommended. The limit test was evaluated in a collaborative study that involved five different hand-held XRF spectrometers used by multiple analysts in six separate laboratories across the United States. In total, more than 1200 measurements were performed. The detection limits estimated for arsenic, lead, mercury, and chromium were 8, 14, 20, and 150 μg/g, respectively.

Development and implementation of a portable grating interferometer system as a standard tool for testing optics at the Advanced Photon Source beamline 1-BM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Assoufid, Lahsen; Shi, Xianbo; Marathe, Shashidhara

We developed a portable X-ray grating interferometer setup as a standard tool for testing optics at the Advanced Photon Source (APS) beamline 1-BM. The interferometer can be operated in phase-stepping, Moiré, or single-grating harmonic imaging mode with 1-D or 2-D gratings. All of the interferometer motions are motorized; hence, it is much easier and quicker to switch between the different modes of operation. A novel aspect of this new instrument is its designed portability. While the setup is designed to be primarily used as a standard tool for testing optics at 1-BM, it could be potentially deployed at other APSmore » beamlines for beam coherence and wavefront characterization or imaging. The design of the interferometer system is described in detail and coherence measurements obtained at the APS 34-ID-E beamline are presented. The coherence was probed in two directions using a 2-D checkerboard, a linear, and a circular grating at X-ray energies of 8 keV, 11 keV, and 18 keV.« less

High-pressure swing system for measurements of radioactive fission gases in air samples

NASA Astrophysics Data System (ADS)

Schell, W. R.; Vives-Battle, J.; Yoon, S. R.; Tobin, M. J.

1999-01-01

Radionuclides emitted from nuclear reactors, fuel reprocessing facilities and nuclear weapons tests are distributed widely in the atmosphere but have very low concentrations. As part of the Comprehensive Test Ban Treaty (CTBT), identification and verification of the emission of radionuclides from such sources are fundamental in maintaining nuclear security. To detect underground and underwater nuclear weapons tests, only the gaseous components need to be analyzed. Equipment has now been developed that can be used to collect large volumes of air, separate and concentrate the radioactive gas constituents, such as xenon and krypton, and measure them quantitatively. By measuring xenon isotopes with different half-lives, the time since the fission event can be determined. Developments in high-pressure (3500 kPa) swing chromatography using molecular sieve adsorbents have provided the means to collect and purify trace quantities of the gases from large volumes of air automatically. New scintillation detectors, together with timing and pulse shaping electronics, have provided the low-background levels essential in identifying the gamma ray, X-ray, and electron energy spectra of specific radionuclides. System miniaturization and portability with remote control could be designed for a field-deployable production model.

Paediatric interventional cardiology: flat detector versus image intensifier using a test object

NASA Astrophysics Data System (ADS)

Vano, E.; Ubeda, C.; Martinez, L. C.; Leyton, F.; Miranda, P.

2010-12-01

Entrance surface air kerma (ESAK) values and image quality parameters were measured and compared for two biplane angiography x-ray systems dedicated to paediatric interventional cardiology, one equipped with image intensifiers (II) and the other one with dynamic flat detectors (FDs). Polymethyl methacrylate phantoms of different thicknesses, ranging from 8 to 16 cm, and a Leeds TOR 18-FG test object were used. The parameters of the image quality evaluated were noise, signal-difference-to-noise ratio (SdNR), high contrast spatial resolution (HCSR) and three figures of merit combining entrance doses and signal-to-noise ratios or HCSR. The comparisons showed a better behaviour of the II-based system in the low contrast region over the whole interval of thicknesses. The FD-based system showed a better performance in HCSR. The FD system evaluated would need around two times more dose than the II system evaluated to reach a given value of SdNR; moreover, a better spatial resolution was measured (and perceived in conventional monitors) for the system equipped with flat detectors. According to the results of this paper, the use of dynamic FD systems does not lead to an automatic reduction in ESAK or to an automatic improvement in image quality by comparison with II systems. Any improvement also depends on the setting of the x-ray systems and it should still be possible to refine these settings for some of the dynamic FDs used in paediatric cardiology.

Affordable and Lightweight High-Resolution X-ray Optics for Astronomical Missions

NASA Technical Reports Server (NTRS)

Zhang, W. W.; Biskach, M. P.; Bly, V. T.; Carter, J. M.; Chan, K. W.; Gaskin, J. A.; Hong, M.; Hohl, B. R.; Jones, W. D.; Kolodziejczak, J. J.

2014-01-01

Future x-ray astronomical missions require x-ray mirror assemblies that provide both high angular resolution and large photon collecting area. In addition, as x-ray astronomy undertakes more sensitive sky surveys, a large field of view is becoming increasingly important as well. Since implementation of these requirements must be carried out in broad political and economical contexts, any technology that meets these performance requirements must also be financially affordable and can be implemented on a reasonable schedule. In this paper we report on progress of an x-ray optics development program that has been designed to address all of these requirements. The program adopts the segmented optical design, thereby is capable of making both small and large mirror assemblies for missions of any size. This program has five technical elements: (1) fabrication of mirror substrates, (2) coating, (3) alignment, (4) bonding, and (5) mirror module systems engineering and testing. In the past year we have made progress in each of these five areas, advancing the angular resolution of mirror modules from 10.8 arc-seconds half-power diameter reported (HPD) a year ago to 8.3 arc-seconds now. These mirror modules have been subjected to and passed all environmental tests, including vibration, acoustic, and thermal vacuum. As such this technology is ready for implementing a mission that requires a 10-arc-second mirror assembly. Further development in the next two years would make it ready for a mission requiring a 5-arc-second mirror assembly. We expect that, by the end of this decade, this technology would enable the x-ray astrophysical community to compete effectively for a major x-ray mission in the 2020s that would require one or more 1-arc-second mirror assemblies for imaging, spectroscopic, timing, and survey studies.

A 7.2 keV spherical crystal backlighter system for Sandia's Z Pulsed Power Facility

NASA Astrophysics Data System (ADS)

Schollmeier, M.; Knapp, P. F.; Ampleford, D. J.; Loisel, G. P.; Robertson, G.; Shores, J. E.; Smith, I. C.; Speas, C. S.; Porter, J. L.; McBride, R. D.

2016-10-01

Many experiments on Sandia's Z facility, a 30 MA, 100 ns rise-time, pulsed-power driver, use a monochromatic Quartz crystal imaging backlighter system at 1.865 keV (Si Heα) or 6.151 keV (Mn Heα) x-ray energy to radiograph an imploding liner (cylindrical tube) or wire array. The x-ray source is generated by the Z-Beamlet Laser (ZBL), which provides up to 4.5 kJ at 527 nm during a 6 ns window. Radiographs of an imploding thick-walled Beryllium liner at a convergence ratio of about 20 [CR =Rin . (0) /Rin . (t) ] were too opaque to identify the inner surface of the liner with high confidence, demonstrating the need for a higher-energy x-ray backlighter between 6 and 10 keV. We present the design, test and first application of a Ge (335) spherical crystal x-ray backlighter system using the 7.242 keV Co Heα resonance line. The system operates at an almost identical Bragg angle as the existing 1.865 and 6.151 keV backlighters, enhancing our capabilities such as two-color, two-frame radiography, without changing detector shielding hardware. SAND No: SAND2016-6724 A. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corp., a wholly owned subsidiary of Lockheed Martin Corp., for the U.S. DoE NNSA under contract DE-AC04-94AL85000.

Singular value description of a digital radiographic detector: Theory and measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kyprianou, Iacovos S.; Badano, Aldo; Gallas, Brandon D.

The H operator represents the deterministic performance of any imaging system. For a linear, digital imaging system, this system operator can be written in terms of a matrix, H, that describes the deterministic response of the system to a set of point objects. A singular value decomposition of this matrix results in a set of orthogonal functions (singular vectors) that form the system basis. A linear combination of these vectors completely describes the transfer of objects through the linear system, where the respective singular values associated with each singular vector describe the magnitude with which that contribution to the objectmore » is transferred through the system. This paper is focused on the measurement, analysis, and interpretation of the H matrix for digital x-ray detectors. A key ingredient in the measurement of the H matrix is the detector response to a single x ray (or infinitestimal x-ray beam). The authors have developed a method to estimate the 2D detector shift-variant, asymmetric ray response function (RRF) from multiple measured line response functions (LRFs) using a modified edge technique. The RRF measurements cover a range of x-ray incident angles from 0 deg. (equivalent location at the detector center) to 30 deg. (equivalent location at the detector edge) for a standard radiographic or cone-beam CT geometric setup. To demonstrate the method, three beam qualities were tested using the inherent, Lu/Er, and Yb beam filtration. The authors show that measures using the LRF, derived from an edge measurement, underestimate the system's performance when compared with the H matrix derived using the RRF. Furthermore, the authors show that edge measurements must be performed at multiple directions in order to capture rotational asymmetries of the RRF. The authors interpret the results of the H matrix SVD and provide correlations with the familiar MTF methodology. Discussion is made about the benefits of the H matrix technique with regards to signal detection theory, and the characterization of shift-variant imaging systems.« less

In-flight observation of long duration gamma-ray glows by aircraft

NASA Astrophysics Data System (ADS)

Kochkin, Pavlo; (Lex) van Deursen, A. P. J.; de Boer, Alte; Bardet, Michiel; Allasia, Cedric; Boissin, Jean Francois; Ostgaard, Nikolai

2017-04-01

The Gamma-Ray Glow is a long-lasting (several seconds to minutes) X- and gamma radiation presumably originated from high-electric field of thunderclouds. Such glows were previously observed by aircraft, balloons, and from the ground. When detected on ground with other particles, i.e. electrons and neutrons, they are usually called Thunderstorm Ground Enhancements (TGEs). Their measured spectra are often consistent with Relativistic Runaway Electron Avalanche (RREA) mechanism. That is why RREA is a commonly accepted explanation for their existence. The gamma-ray glows are observed to be interrupted by lightning discharge, which terminates the high-electric field region. In January 2016 an Airbus A340 factory test aircraft was performing intentional flights through thunderstorms over Northern Australia. The aircraft was equipped with a dedicated in-flight lightning detection system called ILDAS (http://ildas.nlr.nl). The system also contained two scintillation detectors each with 38x38 mm cylinder LaBr3 crystals. While being at 12 km altitude the system detected a gamma-ray flux enhancement 30 times the background counts. It lasted for 20 seconds and was abruptly terminated by a lightning flash. The flash hit the aircraft and its parameters were recorded with 10 ns sampling time including gamma radiation. Ground-based lightning detection network WWLLN detected 4 strikes in the nearby region, all in association with the same flash. The ILDAS system recorded the time-resolved spectrum of the glow. In 6 minutes, after making a U-turn, the aircraft passed the same glow region. Smaller gamma-ray enhancement was again detected. In this presentation we will show the mapped event timeline including airplane, gamma-ray glow, WWLLN, and cloud data. We will discuss the glow's properties, i.e. intensity and differential spectrum, and its possible origin. This result will also be compared to previously reported observations.

Bomb/no bomb: From multivariate analysis to artificial neural systems

NASA Astrophysics Data System (ADS)

Shea, Patrick; Liu, Felix; Yedidia, Barak

1992-05-01

Systems for the detection of explosives hidden in checked airline baggage have been under development at the Science Applications International Corporation (SAIC) for the FAA since 1985. In May of 1987, the first prototype was fielded for testing at San Francisco International Airport. In 1989, the first production unit was field at JFK Airport in New York. Since than, over 550,000 bags have been screened by SAIC units around the world. The system uses thermal neutron activation (TNA) to detect the presence of explosives. In this technique a suitcase on a conveyor belt moves past a source and an array of detectors. Neutrons from the source easily penetrate the luggage, and are absorbed by all of the materials present. Different elements will emit different energy gamma rays after absorbing these neutrons (much like fluorescence). These gamma rays are of a high enough energy that they easily penetrate the luggage, and are detected by a detector array which surrounds the cavity enclosing the suitcase and conveyor belt. The detectors record the number of gamma rays observed at each energy. The number of gamma rays of a characteristic energy which are observed depends on the amount of the element present, its location, the number of neutrons present, and the probability that the element will capture a thermal neutron and emit the gamma ray. Since this probability is a known constant for any particular element, and the number of neutrons present and the number of characteristic gamma rays are measured, the amount of each element and its location can, in theory, be determined from the array of signals. Commercial and military explosives, such as are used by terrorists, have several characteristics which distinguish them from most objects in luggage. On of these characteristics is a high density of nitrogen. A description of the decision algorithms is presented, and the artificial neural system (ANS) is discussed. On-line experience and decision surfaces are also covered.

21 CFR 872.1800 - Extraoral source x-ray system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Extraoral source x-ray system. 872.1800 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1800 Extraoral source x-ray system. (a) Identification. An extraoral source x-ray system is an AC-powered device that produces x-rays and is intended for...

21 CFR 872.1800 - Extraoral source x-ray system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Extraoral source x-ray system. 872.1800 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1800 Extraoral source x-ray system. (a) Identification. An extraoral source x-ray system is an AC-powered device that produces x-rays and is intended for...

21 CFR 872.1800 - Extraoral source x-ray system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Extraoral source x-ray system. 872.1800 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1800 Extraoral source x-ray system. (a) Identification. An extraoral source x-ray system is an AC-powered device that produces x-rays and is intended for...

Use of medical and dental X-ray equipment for nondestructive testing

NASA Technical Reports Server (NTRS)

1969-01-01

Industrial X ray equipment is used for nondestructive testing to detect defects in metal joints, electrical terminal blocks, sealed assemblies, and other hardware. Medical and dental X ray equipment is also used for hardware troubleshooting.

Lumbosacral spine x-ray

MedlinePlus

X-ray - lumbosacral spine; X-ray - lower spine ... The test is done in a hospital x-ray department or your health care provider's office by an x-ray technician. You will be asked to lie on the x-ray ...

Characterization of X-Ray Diffraction System with a Microfocus X-Ray Source and a Polycapillary Optic

NASA Technical Reports Server (NTRS)

Gubarev, Mikhail; Marshall, Joy K.; Ciszak, Ewa; Ponomarev, Igor

2000-01-01

We present here an optimized microfocus x-ray source and polycapillary optic system designed for diffraction of small protein crystals. The x-ray beam is formed by a 5.5mm focal length capillary collimator coupled with a 40 micron x-ray source operating at 46Watts. Measurements of the x-ray flux, the divergence and the spectral characteristics of the beam are presented, This optimized system provides a seven fold greater flux than our recently reported configuration [M. Gubarev, et al., J. of Applied Crystallography (2000) 33, in press]. We now make a comparison with a 5kWatts rotating anode generator (Rigaku) coupled with confocal multilayer focusing mirrors (Osmic, CMF12- 38Cu6). The microfocus x-ray source and polycapillary collimator system delivers 60% of the x-ray flux from the rotating anode system. Additional ways to improve our microfocus x-ray system, and thus increase the x-ray flux will be discussed.

Computer Series, 65. Bits and Pieces, 26.

ERIC Educational Resources Information Center

Moore, John W., Ed.

1985-01-01

Describes: (l) a microcomputer-based system for filing test questions and assembling examinations; (2) microcomputer use in practical and simulated experiments of gamma rays scattering by outer shell electrons; (3) an interactive, screen-oriented, general linear regression program; and (4) graphics drill and game programs for benzene synthesis.…

Modification of the NEMA XR21-2000 cardiac phantom for testing of imaging systems used in endovascular image guided interventions.

PubMed

Ionita, C N; Dohatcu, A; Jain, A; Keleshis, C; Hoffmann, K R; Bednarek, D R; Rudin, S

2009-01-01

X-ray equipment testing using phantoms that mimic the specific human anatomy, morphology, and structure is a very important step in the research, development, and routine quality assurance for such equipment. Although the NEMA XR21 phantom exists for cardiac applications, there is no such standard phantom for neuro-, peripheral and cardio-vascular angiographic applications. We have extended the application of the NEMA XR21-2000 phantom to evaluate neurovascular x-ray imaging systems by structuring it to be head-equivalent; two aluminum plates shaped to fit into the NEMA phantom geometry were added to a 15 cm thick section. Also, to enable digital subtraction angiography (DSA) testing, two replaceable central plates with a hollow slot were made so that various angiographic sections could be inserted into the phantom. We tested the new modified phantom using a flat panel C-arm unit dedicated for endovascular image-guided interventions. All NEMA XR21-2000 standard test sections were used in evaluations with the new "head-equivalent" phantom. DSA and DA are able to be tested using two standard removable blocks having simulated arteries of various thickness and iodine concentrations (AAPM Report 15). The new phantom modifications have the benefits of enabling use of the standard NEMA phantom for angiography in both neuro- and cardio-vascular applications, with the convenience of needing only one versatile phantom for multiple applications. Additional benefits compared to using multiple phantoms are increased portability and lower cost.

Modification of the NEMA XR21-2000 cardiac phantom for testing of imaging systems used in endovascular image guided interventions

NASA Astrophysics Data System (ADS)

Ionita, C. N.; Dohatcu, A.; Jain, A.; Keleshis, C.; Hoffmann, K. R.; Bednarek, D. R.; Rudin, S.

2009-02-01

X-ray equipment testing using phantoms that mimic the specific human anatomy, morphology, and structure is a very important step in the research, development, and routine quality assurance for such equipment. Although the NEMA XR21 phantom exists for cardiac applications, there is no such standard phantom for neuro-, peripheral and cardiovascular angiographic applications. We have extended the application of the NEMA XR21-2000 phantom to evaluate neurovascular x-ray imaging systems by structuring it to be head-equivalent; two aluminum plates shaped to fit into the NEMA phantom geometry were added to a 15 cm thick section. Also, to enable digital subtraction angiography (DSA) testing, two replaceable central plates with a hollow slot were made so that various angiographic sections could be inserted into the phantom. We tested the new modified phantom using a flat panel C-arm unit dedicated for endovascular image-guided interventions. All NEMA XR21-2000 standard test sections were used in evaluations with the new "headequivalent" phantom. DSA and DA are able to be tested using two standard removable blocks having simulated arteries of various thickness and iodine concentrations (AAPM Report 15). The new phantom modifications have the benefits of enabling use of the standard NEMA phantom for angiography in both neuro- and cardio-vascular applications, with the convenience of needing only one versatile phantom for multiple applications. Additional benefits compared to using multiple phantoms are increased portability and lower cost.

The TUS Detector of Extreme Energy Cosmic Rays on Board the Lomonosov Satellite

NASA Astrophysics Data System (ADS)

Klimov, P. A.; Panasyuk, M. I.; Khrenov, B. A.; Garipov, G. K.; Kalmykov, N. N.; Petrov, V. L.; Sharakin, S. A.; Shirokov, A. V.; Yashin, I. V.; Zotov, M. Y.; Biktemerova, S. V.; Grinyuk, A. A.; Grebenyuk, V. M.; Lavrova, M. V.; Tkachev, L. G.; Tkachenko, A. V.; Park, I. H.; Lee, J.; Jeong, S.; Martinez, O.; Salazar, H.; Ponce, E.; Saprykin, O. A.; Botvinko, A. A.; Senkovsky, A. N.; Puchkov, A. E.

2017-11-01

The origin and nature of extreme energy cosmic rays (EECRs), which have energies above the 5\\cdot10^{19} eV—the Greisen-Zatsepin-Kuzmin (GZK) energy limit, is one of the most interesting and complicated problems in modern cosmic-ray physics. Existing ground-based detectors have helped to obtain remarkable results in studying cosmic rays before and after the GZK limit, but have also produced some contradictions in our understanding of cosmic ray mass composition. Moreover, each of these detectors covers only a part of the celestial sphere, which poses problems for studying the arrival directions of EECRs and identifying their sources. As a new generation of EECR space detectors, TUS (Tracking Ultraviolet Set-up), KLYPVE and JEM-EUSO, are intended to study the most energetic cosmic-ray particles, providing larger, uniform exposures of the entire celestial sphere. The TUS detector, launched on board the Lomonosov satellite on April 28, 2016 from Vostochny Cosmodrome in Russia, is the first of these. It employs a single-mirror optical system and a photomultiplier tube matrix as a photo-detector and will test the fluorescent method of measuring EECRs from space. Utilizing the Earth's atmosphere as a huge calorimeter, it is expected to detect EECRs with energies above 10^{20} eV. It will also be able to register slower atmospheric transient events: atmospheric fluorescence in electrical discharges of various types including precipitating electrons escaping the magnetosphere and from the radiation of meteors passing through the atmosphere. We describe the design of the TUS detector and present results of different ground-based tests and simulations.

CGRO Guest Investigator Program

NASA Technical Reports Server (NTRS)

Begelman, Mitchell C.

1997-01-01

The following are highlights from the research supported by this grant: (1) Theory of gamma-ray blazars: We studied the theory of gamma-ray blazars, being among the first investigators to propose that the GeV emission arises from Comptonization of diffuse radiation surrounding the jet, rather than from the synchrotron-self-Compton mechanism. In related work, we uncovered possible connections between the mechanisms of gamma-ray blazars and those of intraday radio variability, and have conducted a general study of the role of Compton radiation drag on the dynamics of relativistic jets. (2) A Nonlinear Monte Carlo code for gamma-ray spectrum formation: We developed, tested, and applied the first Nonlinear Monte Carlo (NLMC) code for simulating gamma-ray production and transfer under much more general (and realistic) conditions than are accessible with other techniques. The present version of the code is designed to simulate conditions thought to be present in active galactic nuclei and certain types of X-ray binaries, and includes the physics needed to model thermal and nonthermal electron-positron pair cascades. Unlike traditional Monte-Carlo techniques, our method can accurately handle highly non-linear systems in which the radiation and particle backgrounds must be determined self-consistently and in which the particle energies span many orders of magnitude. Unlike models based on kinetic equations, our code can handle arbitrary source geometries and relativistic kinematic effects In its first important application following testing, we showed that popular semi-analytic accretion disk corona models for Seyfert spectra are seriously in error, and demonstrated how the spectra can be simulated if the disk is sparsely covered by localized 'flares'.

Non-Quiescent X-ray Emission from Neutron Stars and Black Holes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tournear, Derek M

X-ray astronomy began with the detection of the persistent source Scorpius X-1. Shortly afterwards, sources were detected that were variable. Centaurus X-2, was determined to be an X-ray transient, having a quiescent state, and a state that was much brighter. As X-ray astronomy progressed, classifications of transient sources developed. One class of sources, believed to be neutron stars, undergo extreme luminosity transitions lasting a few seconds. These outbursts are believed to be thermonuclear explosions occurring on the surface of neutron stars (type I X-ray bursts). Other sources undergo luminosity changes that cannot be explained by thermonuclear burning and last formore » days to months. These sources are soft X-ray transients (SXTs) and are believed to be the result of instabilities in the accretion of matter onto either a neutron star or black hole. Type I X-ray bursts provide a tool for probing the surfaces of neutron stars. Requiring a surface for the burning has led authors to use the presence of X-ray bursts to rule out the existence of a black hole (where an event horizon exists not a surface) for systems which exhibit type I X-ray bursts. Distinguishing between neutron stars and black holes has been a problem for decades. Narayan and Heyl have developed a theoretical framework to convert suitable upper limits on type I X-ray bursts from accreting black hole candidates (BHCs) into evidence for an event horizon. We survey 2101.2 ks of data from the USA X-ray timing experiment and 5142 ks of data from the Rossi X-ray Timing Explorer (RXTE) experiment to obtain the first formal constraint of this type. 1122 ks of neutron star data yield a population averaged mean burst rate of 1.7 {+-} 0.4 x 10{sup -5} bursts s{sup -1}, while 6081 ks of BHC data yield a 95% confidence level upper limit of 4.9 x 10{sup -7} bursts s{sup -1}. Applying the framework of Narayan and Heyl we calculate regions of luminosity where the neutron stars are expected to burst and the BHCs would be expected to burst if they had a similar surface. In this luminosity region 464 ks of neutron star data yield an averaged mean burst rate of 4.1 {+-} 0.9 x 10{sup -5} bursts s{sup -1}, and 1512 ks of BHC data yield a 95% confidence level upper limit of 2.0 x 10{sup -6} bursts s{sup -1} and a strong limit that BHCs do not burst with a rate similar to the rate of neutron stars in these regions. This gives evidence that BHCs do not have surfaces. In addition to studying type I X-ray bursts, we analyzed the SXT behavior. In particular, 4U 1630-47, was analyzed throughout its 1999 outburst. This source is one of the oldest known SXTs. This source is assumed to be a BHC in a low-mass X-ray binary system. Despite the length of time devoted to studying this source, there is still little known about it. We report the results of timing and spectral analysis on the 1999 outburst, and compare these results to other outbursts of 4U 1630-47. We found this source progressed from a low-hard state to a high-soft state and then rapidly transitioned back into the low-hard state before returning to quiescence. Timing analysis detected a low frequency quasi-periodic oscillation (LFQPO) during the initial rise of the outburst, which disappeared and did not return. The variability in the X-ray flux in the 0.1-2000 Hz frequency range is low during the high state, but increases as the source progresses into the low-hard state. The next generation Gamma Ray Large Area Space Telescope (GLAST), will measure astrophysical phenomena in the 20 MeV--a few TeV energy range. We describe preliminary design and testing of GLAST. The detector is based on a silicon tracker with similar design characteristics of vertex detectors used in high-energy physics experiments at accelerator based facilities. A beam test engineering model was designed, constructed, and tested at SLAC in 1999-2000. We describe this test, and discuss how the results from this test can improve and demonstrate the viability of the GLAST technology.« less

X-ray radiation detectors of ``scintillator-photoreceiving device type'' for industrial digital radiography with improved spatial resolution

NASA Astrophysics Data System (ADS)

Ryzhykov, V. D.; Lysetska, O. K.; Opolonin, O. D.; Kozin, D. N.

2003-06-01

Main types of photoreceivers used in X-ray digital radiography systems are luminescent screens that transfer the optical image onto charge collection instruments, which require cooling, and semiconductor silicon detectors, which limit the contrast sensitivity. We have developed and produced X-ray radiation detectors of "scintillator-photoreceiving device" (S-PRD) type, which are integrally located on the inverse side of the photodiode (PD). The receiving-converting circuit (RCC) is designed for data conversion into digital form and their input into PC. Software is provided for RCC control and image visualization. Main advantages of these detectors are high industrial resolution (3-5 line pairs per mm), detecting activity up to 20 μm, controlled sensitivity, low weight and small size, imaging low (0.1-0.3 mrad) object dose in real time. In this work, main characteristics of 32-, 64- and 1024-channel detectors of S-PRD type were studied and compared for X-ray sensitivity with S-PD detectors. Images of the tested objects have been obtained. Recommendations are given on the use of different scintillation materials, depending upon the purpose of a digital radiographic system. The detectors operate in a broad energy range of ionizing radiation, hence the size of the controlled object is not limited. The system is sufficiently powerful to ensure frontal (through two walls) observation of pipelines with wall thickness up to 10 cm.

Biomechanical model of batoid (skates and rays) pectoral fins predicts the influence of skeletal structure on fin kinematics: implications for bio-inspired design.

PubMed

Russo, R S; Blemker, S S; Fish, F E; Bart-Smith, H

2015-06-16

Growing interest in the development of bio-inspired autonomous underwater vehicles (AUVs) has motivated research in understanding the mechanisms behind the propulsion systems of marine animals. For example, the locomotive behavior of rays (Batoidea) by movement of the pectoral fins is of particular interest due to their superior performance characteristics over contemporary AUV propulsion systems. To better understand the mechanics of pectoral fin propulsion, this paper introduces a biomechanical model that simulates how batoid skeletal structures function to achieve the swimming locomotion observed in nature. Two rays were studied, Dasyatis sabina (Atlantic ray), and Rhinoptera bonasus (cownose ray). These species were selected because they exhibit very different swimming styles (undulation versus oscillation), but all use primarily their pectoral fins for propulsion (unlike electric rays or guitarfishes). Computerized tomography scans of each species were taken to image the underlying structure, which reveal a complex system of cartilaginous joints and linkages. Data collected from these images were used to quantify the complete skeletal morphometry of each batoid fin. Morphological differences were identified in the internal cartilage arrangement between each species including variations in the orientation of the skeletal elements, or radials, and the joint patterns between them, called the inter-radial joint pattern. These data were used as the primary input into the biomechanical model to couple a given ray skeletal structure with various swimming motions. A key output of the model is an estimation of the uniaxial strain that develops in the skeletal connective tissue in order for the structure to achieve motions observed during swimming. Tensile load tests of this connective tissue were conducted to further investigate the implications of the material strain predictions. The model also demonstrates that changes in the skeletal architecture (e.g., joint positioning) will effect fin deformation characteristics. Ultimately, the results of this study can be used to guide the design of optimally performing bio-inspired AUVs.

Combined UHV/high-pressure catalysis setup for depth-resolved near-surface spectroscopic characterization and catalytic testing of model catalysts

NASA Astrophysics Data System (ADS)

Mayr, Lukas; Rameshan, Raffael; Klötzer, Bernhard; Penner, Simon; Rameshan, Christoph

2014-05-01

An ultra-high vacuum (UHV) setup for "real" and "inverse" model catalyst preparation, depth-resolved near-surface spectroscopic characterization, and quantification of catalytic activity and selectivity under technologically relevant conditions is described. Due to the all-quartz reactor attached directly to the UHV-chamber, transfer of the catalyst for in situ testing without intermediate contact to the ambient is possible. The design of the UHV-compatible re-circulating batch reactor setup allows the study of reaction kinetics under close to technically relevant catalytic conditions up to 1273 K without contact to metallic surfaces except those of the catalyst itself. With the attached differentially pumped exchangeable evaporators and the quartz-microbalance thickness monitoring equipment, a reproducible, versatile, and standardised sample preparation is possible. For three-dimensional near-surface sample characterization, the system is equipped with a hemispherical analyser for X-ray photoelectron spectroscopy (XPS), electron-beam or X-ray-excited Auger-electron spectroscopy, and low-energy ion scattering measurements. Due the dedicated geometry of the X-ray gun (54.7°, "magic angle") and the rotatable sample holder, depth analysis by angle-resolved XPS measurements can be performed. Thus, by the combination of characterisation methods with different information depths, a detailed three-dimensional picture of the electronic and geometric structure of the model catalyst can be obtained. To demonstrate the capability of the described system, comparative results for depth-resolved sample characterization and catalytic testing in methanol steam reforming on PdGa and PdZn near-surface intermetallic phases are shown.

Lessons Learned During Cryogenic Optical Testing of the Advanced Mirror System Demonstrators (AMSDs)

NASA Technical Reports Server (NTRS)

Hadaway, James; Reardon, Patrick; Geary, Joseph; Robinson, Brian; Stahl, Philip; Eng, Ron; Kegley, Jeff

2004-01-01

Optical testing in a cryogenic environment presents a host of challenges above and beyond those encountered during room temperature testing. The Advanced Mirror System Demonstrators (AMSDs) are 1.4 m diameter, ultra light-weight (<20 kg/mA2), off-axis parabolic segments. They are required to have 250 nm PV & 50 nm RMS surface figure error or less at 35 K. An optical testing system, consisting of an Instantaneous Phase Interferometer (PI), a diffractive null corrector (DNC), and an Absolute Distance Meter (ADM), was used to measure the surface figure & radius-of-curvature of these mirrors at the operational temperature within the X-Ray Calibration Facility (XRCF) at Marshall Space Flight Center (MSFC). The Ah4SD program was designed to improve the technology related to the design, fabrication, & testing of such mirrors in support of NASA s James Webb Space Telescope (JWST). This paper will describe the lessons learned during preparation & cryogenic testing of the AMSDs.

The POPOP4 library and codes for preparing secondary gamma-ray production cross sections

NASA Technical Reports Server (NTRS)

Ford, W. E., III

1972-01-01

The POPOP4 code for converting secondary gamma ray yield data to multigroup secondary gamma ray production cross sections and the POPOP4 library of secondary gamma ray yield data are described. Recent results of the testing of uranium and iron data sets from the POPOP4 library are given. The data sets were tested by comparing calculated secondary gamma ray pulse height spectra measured at the ORNL TSR-II reactor.

Attenuation characteristics of fiberoptic plates for digital mammography and other X-ray imaging applications.

PubMed

Vedantham, S; Karellas, A; Suryanarayanan, S

2003-01-01

Spatially coherent fiberoptic plates are important components of some charge-coupled device (CCD)-based x-ray imaging systems. These plates efficiently transmit scintillations from the phosphor, and also filter out x-rays not absorbed by the phosphor, thus protecting the CCD from direct x-ray interaction. The thickness of the fiberoptic plate and the CCD package present a significant challenge in the design of a digital x-ray cassette capable of insertion into the existing film-screen cassette holders of digital mammography systems. This study was performed with an aim to optimize fiberoptic plate thickness. Attenuation measurements were performed on nine fiberoptic plates varying in material composition that exhibit desirable optical characteristics such as good coupling efficiency. Mammographic spectra from a clinical mammographic system and an Americium-241 (Am-241) source (59.54 KeV) were used. The spectra were recorded with a high-resolution cadmium zinc telluride (CZT)-based spectrometer and corrected for dead time and pile-up. The linear attenuation coefficients varied by a factor of 3 in the set of tested fiberoptic plates at both mammographic energies and 59.54 keV. Our results suggest that a 3-mm thick high-absorption plate might provide adequate for shielding at mammographic energies. A thickness of 2-mm is feasible for mammographic applications with further optimization of the fiberoptic plate composition by incorporating non-scintillating, high-atomic number material. This would allow more space for cooling components of the cassette and for a more compact device, which is critical for clinical implementation of the technology.

Medical ultrasonic tomographic system

NASA Technical Reports Server (NTRS)

Heyser, R. C.; Lecroissette, D. H.; Nathan, R.; Wilson, R. L.

1977-01-01

An electro-mechanical scanning assembly was designed and fabricated for the purpose of generating an ultrasound tomogram. A low cost modality was demonstrated in which analog instrumentation methods formed a tomogram on photographic film. Successful tomogram reconstructions were obtained on in vitro test objects by using the attenuation of the fist path ultrasound signal as it passed through the test object. The nearly half century tomographic methods of X-ray analysis were verified as being useful for ultrasound imaging.

The Mammographic Head Demonstrator Developed in the Framework of the “IMI” Project:. First Imaging Tests Results

NASA Astrophysics Data System (ADS)

Bisogni, Maria Giuseppina

2006-04-01

In this paper we report on the performances and the first imaging test results of a digital mammographic demonstrator based on GaAs pixel detectors. The heart of this prototype is the X-ray detection unit, which is a GaAs pixel sensor read-out by the PCC/MEDIPIXI circuit. Since the active area of the sensor is 1 cm2, 18 detectors have been organized in two staggered rows of nine chips each. To cover the typical mammographic format (18 × 24 cm2) a linear scanning is performed by means of a stepper motor. The system is integrated in mammographic equipment comprehending the X-ray tube, the bias and data acquisition systems and the PC-based control system. The prototype has been developed in the framework of the integrated Mammographic Imaging (IMI) project, an industrial research activity aiming to develop innovative instrumentation for morphologic and functional imaging. The project has been supported by the Italian Ministry of Education, University and Research (MIUR) and by five Italian High Tech companies in collaboration with the universities of Ferrara, Roma “La Sapienza”, Pisa and the INFN.

Automatic tool alignment in a backscatter X-ray scanning system

DOEpatents

Garretson, Justin; Hobart, Clinton G.; Gladwell, Thomas S.; Monda, Mark J.

2015-11-17

Technologies pertaining to backscatter x-ray scanning systems are described herein. The backscatter x-ray scanning system includes an x-ray source, which directs collimated x-rays along a plurality of output vectors towards a target. A detector detects diffusely reflected x-rays subsequent to respective collimated x-rays impacting the target, and outputs signals indicative of parameters of the detected x-rays. An image processing system generates an x-ray image based upon parameters of the detected x-rays, wherein each pixel in the image corresponds to a respective output vector. A user selects a particular portion of the image, and a medical device is positioned such that its directional axis is coincident with the output vector corresponding to at least one pixel in the portion of the image.

Automatic tool alignment in a backscatter x-ray scanning system

DOEpatents

Garretson, Justin; Hobart, Clinton G.; Gladwell, Thomas S.; Monda, Mark J.

2015-06-16

Technologies pertaining to backscatter x-ray scanning systems are described herein. The backscatter x-ray scanning system includes an x-ray source, which directs collimated x-rays along a plurality of output vectors towards a target. A detector detects diffusely reflected x-rays subsequent to respective collimated x-rays impacting the target, and outputs signals indicative of parameters of the detected x-rays. An image processing system generates an x-ray image based upon parameters of the detected x-rays, wherein each pixel in the image corresponds to a respective output vector. A user selects a particular portion of the image, and a tool is positioned such that its directional axis is coincident with the output vector corresponding to at least one pixel in the portion of the image.

Understanding the Unusual X-Ray Emission Properties of the Massive, Close Binary WR 20a: A High Energy Window into the Stellar Wind Initiation Region

NASA Astrophysics Data System (ADS)

Montes, Gabriela; Ramirez-Ruiz, Enrico; De Colle, Fabio; Strickler, Rachel

2013-11-01

The problem of explaining the X-ray emission properties of the massive, close binary WR 20a is discussed. Located near the cluster core of Westerlund 2, WR 20a is composed of two nearly identical Wolf-Rayet stars of 82 and 83 solar masses orbiting with a period of only 3.7 days. Although Chandra observations were taken during the secondary optical eclipse, the X-ray light curve shows no signs of a flux decrement. In fact, WR 20a appears slightly more X-ray luminous and softer during the optical eclipse, opposite to what has been observed in other binary systems. To aid in our interpretation of the data, we compare with the results of hydrodynamical simulations using the adaptive mesh refinement code Mezcal which includes radiative cooling and a radiative acceleration force term. It is shown that the X-ray emission can be successfully explained in models where the wind-wind collision interface in this system occurs while the outflowing material is still being accelerated. Consequently, WR 20a serves as a critical test-case for how radiatively driven stellar winds are initiated and how they interact. Our models not only procure a robust description of current Chandra data, which cover the orbital phases between 0.3 and 0.6, but also provide detailed predictions over the entire orbit.

Non-Destructive Inspection Methods for Propulsion Systems and Components

DTIC Science & Technology

1979-04-01

debris on a microfilter, followed by X-ray examination of the deposits and atomic absorption analysis of the deposits dissolved in hydrochloric acid ...thickness. A single naphthenic mineral oil was used for all tests in a once through system to avoid particle contamination. It was found that: the total...Superalliage. Alliage nickel. Acier inoxydable. Mesure expdrimentale. Transformation phase. Oxydation . Carbonisation. Aube turbine. Ddtection ddfaut. Contr6le

GEMINI-TITAN (GT)-8 - EXTRAVEHICULAR (EV) EQUIPMENT & SUIT - MSC

NASA Image and Video Library

1966-01-18

S66-17475 (18 Jan. 1966) --- Test subject Fred Spress, Crew Systems Division, wears the spacesuit and extravehicular equipment planned for use by astronaut David R. Scott. The helmet is equipped with a gold-plated visor to shield the astronaut's face from unfiltered sun rays. The system is composed of a life support pack worn on the chest and a support pack worn on the back. Photo credit: NASA

GEMINI-TITAN (GT)-8 - EXTRAVEHICULAR (EV) EQUIPMENT & SUIT - MSC

NASA Image and Video Library

1966-01-18

S66-17480 (18 Jan. 1966) --- Test subject Fred Spress, Crew Systems Division, wears the spacesuit and extravehicular equipment planned for use by astronaut David R. Scott. The helmet is equipped with a gold-plated visor to shield the astronaut's face from unfiltered sun rays. The system is composed of a life support pack worn on the chest and a support pack worn on the back. Photo credit: NASA

Stabilization of lead in an alkali-activated municipal solid waste incineration fly ash-Pyrophyllite-based system.

PubMed

Shiota, Kenji; Nakamura, Takafumi; Takaoka, Masaki; Aminuddin, Siti Fatimah; Oshita, Kazuyuki; Fujimori, Takashi

2017-10-01

This work focuses on the stabilization and speciation of lead (Pb) in a composite solid produced from an alkali-activated municipal solid waste incineration fly ash (MSWIFA)-pyophyllite-based system. The solid product was synthesized after mixtures of raw materials (dehydrated pyrophyllite, MSWIFA, 14 mol/L aqueous sodium hydroxide, and sodium silicate solution) were cured at 105 °C for 24 h. The product could reduce the leaching of Pb and the Pb concentration in the leachate was 7.0 × 10 -3 using the Japanese leaching test and 9.7 × 10 -4  mg/L using toxicity characteristics leaching procedure method, which satisfied the respective test criteria and successfully stabilized Pb in this system. The solid product had a compressive strength of 2 MPa and consisted mainly of crystalline phases. Scanning electron microscopy with X-ray analysis and X-ray absorption fine structure suggested that Pb was present along with Al, Si, and O, and that the atomic environment around the Pb was similar to that of PbSiO 3 . These results suggest that the alkali-activated MSWIFA-pyrophyllite-based system could be used to stabilize Pb in MSWIFA. Copyright © 2017 Elsevier Ltd. All rights reserved.

Creating an EPICS Based Test Stand Development System for a BPM Digitizer of the Linac Coherent Light Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2011-06-22

The Linac Coherent Light Source (LCLS) is required to deliver a high quality electron beam for producing coherent X-rays. As a result, high resolution beam position monitoring is required. The Beam Position Monitor (BPM) digitizer acquires analog signals from the beam line and digitizes them to obtain beam position data. Although Matlab is currently being used to test the BPM digitizer?s functions and capability, the Controls Department at SLAC prefers to use Experimental Physics and Industrial Control Systems (EPICS). This paper discusses the transition of providing similar as well as enhanced functionalities, than those offered by Matlab, to test themore » digitizer. Altogether, the improved test stand development system can perform mathematical and statistical calculations with the waveform signals acquired from the digitizer and compute the fast Fourier transform (FFT) of the signals. Finally, logging of meaningful data into files has been added.« less

Integral measurements of neutron and gamma-ray leakage fluxes from the Little Boy replica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muckenthaler, F.J.

This report presents integral measurements of neutron and gamma-ray leakage fluxes from a critical mockup of the Hiroshima bomb Little Boy at Los Alamos National Laobratory with detector systems developed by Oak Ridge National Laboratory. Bonner ball detectors were used to map the neutron fluxes in the horizontal midplane at various distances from the mockup and for selected polar angles, keeping the source-detector separation constant. Gamma-ray energy deposition measurements were made with thermoluminescent detectors at several locations on the iron shell of the source mockup. The measurements were performed as part of a larger progam to provide benchmark data formore » testing the methods used to calculate the radiation released from the Little Boy bomb over Hiroshima. 3 references, 10 figures.« less

Characterization of double oxide system Cu-Cr-O supported on γ-Al2O3

NASA Astrophysics Data System (ADS)

Cherkezova-Zheleva, Z.; Kolev, H.; Krstić, J.; Dimitrov, D.; Ivanov, K.; Loncarević, D.; Jovanović, D.; Mitov, I.

2009-09-01

Series of alumina supported chromium-copper catalysts were prepared by co-impregnation method. The samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy and UV-visible diffuse reflectance spectroscopy. Dispersion and porosity was also obtained. The experimental and catalytic test results have drawn a conclusion that an interaction between copper and chromium ions takes place. This interaction is responsible for the enhanced catalytic activity of studied catalysts in reaction of total oxidation of industrial formaldehyde production exhaust gas, which contains CO, dimethyl ether and methanol as main components.

Thermal detectors for high resolution spectroscopy

NASA Technical Reports Server (NTRS)

Mccammon, D.; Juda, M.; Zhang, J.; Kelley, R. L.; Moseley, S. H.; Szymkowiak, A. E.

1986-01-01

Cryogenic microcalorimeters can be made sensitive enough to measure the energy deposited by a single particle or X-ray photon with an accuracy of about one electron volt. It may also be possible to construct detectors of several-kilograms mass whose resolution is only a few times worse than this. Data from relatively crude test devices are in good agreement with thermal performance calculations, and a total system noise of 11 eV FWHM has been obtained for a silicon detector operating at 98 mK. Observations of 35 eV FWHM for 6-keV X-rays with a different device have been made.

Accelerated radiation damage testing of x-ray mask membrane materials

NASA Astrophysics Data System (ADS)

Seese, Philip A.; Cummings, Kevin D.; Resnick, Douglas J.; Yanof, Arnold W.; Johnson, William A.; Wells, Gregory M.; Wallace, John P.

1993-06-01

An accelerated test method and resulting metrology data are presented to show the effects of x- ray radiation on various x-ray mask membrane materials. A focused x-ray beam effectively reduces the radiation time to 1/5 of that required by normal exposure beam flux. Absolute image displacement results determined by this method indicate imperceptible movement for boron-doped silicon and silicon carbide membranes at a total incident dose of 500 KJ/cm2, while image displacement for diamond is 50 nm at 150 KJ/cm2 and silicon nitride is 70 nm at 36 KJ/cm2. Studies of temperature rise during the radiation test and effects of the high flux radiation, i.e., reciprocity tests, demonstrate the validity of this test method.

GammaScorpion: mobile gamma-ray tomography system for early detection of basal stem rot in oil palm plantations

NASA Astrophysics Data System (ADS)

Abdullah, Jaafar; Hassan, Hearie; Shari, Mohamad Rabaie; Mohd, Salzali; Mustapha, Mahadi; Mahmood, Airwan Affendi; Jamaludin, Shahrizan; Ngah, Mohd Rosdi; Hamid, Noor Hisham

2013-03-01

Detection of the oil palm stem rot disease Ganoderma is a major issue in estate management and production in Malaysia. Conventional diagnostic techniques are difficult and time consuming when using visual inspection, and destructive and expensive when based on the chemical analysis of root or stem tissue. As an alternative, a transportable gamma-ray computed tomography system for the early detection of basal stem rot (BSR) of oil palms due to Ganoderma was developed locally at the Malaysian Nuclear Agency, Kajang, Malaysia. This system produces high quality tomographic images that clearly differentiate between healthy and Ganoderma infected oil palm stems. It has been successfully tested and used to detect the extent of BSR damage in oil palm plantations in Malaysia without the need to cut down the trees. This method offers promise for in situ inspection of oil palm stem diseases compared to the more conventional methods.

Readiness of the ATLAS Tile Calorimeter for LHC collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aad, G.; Abbott, B.; Abdallah, J.

The Tile hadronic calorimeter of the ATLAS detector has undergone extensive testing in the experimental hall since its installation in late 2005. The readout, control and calibration systems have been fully operational since 2007 and the detector has successfully collected data from the LHC single beams in 2008 and first collisions in 2009. This paper gives an overview of the Tile Calorimeter performance as measured using random triggers, calibration data, data from cosmic ray muons and single beam data. The detector operation status, noise characteristics and performance of the calibration systems are presented, as well as the validation of themore » timing and energy calibration carried out with minimum ionising cosmic ray muons data. The calibration systems' precision is well below the design value of 1%. The determination of the global energy scale was performed with an uncertainty of 4%. © 2010 CERN for the benefit of the ATLAS collaboration.« less

Readiness of the ATLAS Tile Calorimeter for LHC collisions

DOE PAGES

Aad, G.; Abbott, B.; Abdallah, J.; ...

2010-12-08

The Tile hadronic calorimeter of the ATLAS detector has undergone extensive testing in the experimental hall since its installation in late 2005. The readout, control and calibration systems have been fully operational since 2007 and the detector has successfully collected data from the LHC single beams in 2008 and first collisions in 2009. This paper gives an overview of the Tile Calorimeter performance as measured using random triggers, calibration data, data from cosmic ray muons and single beam data. The detector operation status, noise characteristics and performance of the calibration systems are presented, as well as the validation of themore » timing and energy calibration carried out with minimum ionising cosmic ray muons data. The calibration systems' precision is well below the design value of 1%. The determination of the global energy scale was performed with an uncertainty of 4%. © 2010 CERN for the benefit of the ATLAS collaboration.« less

KSC-99pc0167

NASA Image and Video Library

1999-02-06

At the Vertical Processing Facility (VPF), workers (left) drive, by remote control, the rear bogie away from the VPF. The bogie is part of the tractor-trailer rig called the Space Cargo Transportation System that helped move the Chandra X-ray Observatory (right) from the Shuttle Landing Facility into the VPF. Chandra arrived at KSC on Thursday, Feb. 4, aboard an Air Force C-5 Galaxy aircraft. In the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

Closed and Not Closed: Mitigating a Mystery on Chandra's Door

NASA Technical Reports Server (NTRS)

Odom, Brian

2015-01-01

The Chandra X-ray Observatory is part of NASA's fleet of "Great Observatories" along with the Hubble Space Telescope, the Spitzer Space Telescope, and the now deorbited Compton Gamma Ray Observatory. The observatory was designed to detect x-ray emissions from some of the hottest regions of the galaxy including exploded stars, clusters of galaxies, and matter around black holes. One of the observatory's key scientific instruments is the Advanced CCD Imaging Spectrometer (ACIS), which is one of four primary and two focal plane instruments. Due to the sensitivity of the charged coupled devices (CCD's), an aperture door was designed and built by Lockheed-Martin that protected the instrument during testing and the time leading up to launch. The design called for a system of wax actuators (manufactured by STARSYS Corp) to be used as components in a rotary actuator that would open and close the door during ground testing and on-orbit operations. Another feature of the design was an internal shear disc located in each actuator to prevent excessive internal pressure and to shield other components from damage.

Potentials of Optical Damage Assessment Techniques in Automotive Crash-Concepts composed of FRP-Steel Hybrid Material Systems

NASA Astrophysics Data System (ADS)

Dlugosch, M.; Spiegelhalter, B.; Soot, T.; Lukaszewicz, D.; Fritsch, J.; Hiermaier, S.

2017-05-01

With car manufacturers simultaneously facing increasing passive safety and efficiency requirements, FRP-metal hybrid material systems are one way to design lightweight and crashworthy vehicle structures. Generic automotive hybrid structural concepts have been tested under crash loading conditions. In order to assess the state of overall damage and structural integrity, and primarily to validate simulation data, several NDT techniques have been assessed regarding their potential to detect common damage mechanisms in such hybrid systems. Significant potentials were found particularly in combining 3D-topography laser scanning and X-Ray imaging results. Ultrasonic testing proved to be limited by the signal coupling quality on damaged or curved surfaces.

History of Chandra X-Ray Observatory

NASA Image and Video Library

1996-12-16

This is a photograph of the Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), High Resolution Mirror Assembly (HRMA) integration at the X-Ray Calibration Facility (XRCF) at the Marshall Space Flight Center (MSFC). The AXAF was renamed CXO in 1999. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It observes x-rays from high-energy regions of the universe, such as hot gas in the remnants of exploded stars. The HRMA, the heart of the telescope system, is contained in the cylindrical "telescope" portion of the observatory. Since high-energy x-rays would penetrate a normal mirror, special cylindrical mirrors were created. The two sets of four nested mirrors resemble tubes within tubes. Incoming x-rays graze off the highly polished mirror surface and are furneled to the instrument section for detection and study. MSFC's XRCF is the world's largest, most advanced laboratory for simulating x-ray emissions from distant celestial objects. It produces a space-like environment in which components related to x-ray telescope imaging are tested and the quality of their performances in space is predicted. TRW, Inc. was the prime contractor for the development of the CXO and NASA's MSFC was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The CXO was launched July 22, 1999 aboard the Space Shuttle Columbia (STS-93).

History of Chandra X-Ray Observatory

NASA Image and Video Library

1997-12-16

This is a photograph of the Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), High Resolution Mirror Assembly (HRMA) integration at the X-Ray Calibration Facility (XRCF) at the Marshall Space Flight Center (MSFC). The AXAF was renamed CXO in 1999. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It observes x-rays from high-energy regions of the universe, such as hot gas in the remnants of exploded stars. The HRMA, the heart of the telescope system, is contained in the cylindrical "telescope" portion of the observatory. Since high-energy x-rays would penetrate a normal mirror, special cylindrical mirrors were created. The two sets of four nested mirrors resemble tubes within tubes. Incoming x-rays graze off the highly polished mirror surface and are furneled to the instrument section for detection and study. MSFC's XRCF is the world's largest, most advanced laboratory for simulating x-ray emissions from distant celestial objects. It produces a space-like environment in which components related to x-ray telescope imaging are tested and the quality of their performances in space is predicted. TRW, Inc. was the prime contractor for the development of the CXO and NASA's MSCF was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The CXO was launched July 22, 1999 aboard the Space Shuttle Columbia (STS-93).

Simulation tools for analyzer-based x-ray phase contrast imaging system with a conventional x-ray source

NASA Astrophysics Data System (ADS)

Caudevilla, Oriol; Zhou, Wei; Stoupin, Stanislav; Verman, Boris; Brankov, J. G.

2016-09-01

Analyzer-based X-ray phase contrast imaging (ABI) belongs to a broader family of phase-contrast (PC) X-ray imaging modalities. Unlike the conventional X-ray radiography, which measures only X-ray absorption, in PC imaging one can also measures the X-rays deflection induced by the object refractive properties. It has been shown that refraction imaging provides better contrast when imaging the soft tissue, which is of great interest in medical imaging applications. In this paper, we introduce a simulation tool specifically designed to simulate the analyzer-based X-ray phase contrast imaging system with a conventional polychromatic X-ray source. By utilizing ray tracing and basic physical principles of diffraction theory our simulation tool can predicting the X-ray beam profile shape, the energy content, the total throughput (photon count) at the detector. In addition we can evaluate imaging system point-spread function for various system configurations.

The application of wavelet denoising in material discrimination system

NASA Astrophysics Data System (ADS)

Fu, Kenneth; Ranta, Dale; Guest, Clark; Das, Pankaj

2010-01-01

Recently, the need for cargo inspection imaging systems to provide a material discrimination function has become desirable. This is done by scanning the cargo container with x-rays at two different energy levels. The ratio of attenuations of the two energy scans can provide information on the composition of the material. However, with the statistical error from noise, the accuracy of such systems can be low. Because the moving source emits two energies of x-rays alternately, images from the two scans will not be identical. That means edges of objects in the two images are not perfectly aligned. Moreover, digitization creates blurry-edge artifacts. Different energy x-rays produce different edge spread functions. Those combined effects contribute to a source of false classification namely, the "edge effect." Other types of false classification are caused by noise, mainly Poisson noise associated with photons. The Poisson noise in xray images can be dealt with using either a Wiener filter or a wavelet shrinkage denoising approach. In this paper, we propose a method that uses the wavelet shrinkage denoising approach to enhance the performance of the material identification system. Test results show that this wavelet-based approach has improved performance in object detection and eliminating false positives due to the edge effects.

GPU-based multi-volume ray casting within VTK for medical applications.

PubMed

Bozorgi, Mohammadmehdi; Lindseth, Frank

2015-03-01

Multi-volume visualization is important for displaying relevant information in multimodal or multitemporal medical imaging studies. The main objective with the current study was to develop an efficient GPU-based multi-volume ray caster (MVRC) and validate the proposed visualization system in the context of image-guided surgical navigation. Ray casting can produce high-quality 2D images from 3D volume data but the method is computationally demanding, especially when multiple volumes are involved, so a parallel GPU version has been implemented. In the proposed MVRC, imaginary rays are sent through the volumes (one ray for each pixel in the view), and at equal and short intervals along the rays, samples are collected from each volume. Samples from all the volumes are composited using front to back α-blending. Since all the rays can be processed simultaneously, the MVRC was implemented in parallel on the GPU to achieve acceptable interactive frame rates. The method is fully integrated within the visualization toolkit (VTK) pipeline with the ability to apply different operations (e.g., transformations, clipping, and cropping) on each volume separately. The implemented method is cross-platform (Windows, Linux and Mac OSX) and runs on different graphics card (NVidia and AMD). The speed of the MVRC was tested with one to five volumes of varying sizes: 128(3), 256(3), and 512(3). A Tesla C2070 GPU was used, and the output image size was 600 × 600 pixels. The original VTK single-volume ray caster and the MVRC were compared when rendering only one volume. The multi-volume rendering system achieved an interactive frame rate (> 15 fps) when rendering five small volumes (128 (3) voxels), four medium-sized volumes (256(3) voxels), and two large volumes (512(3) voxels). When rendering single volumes, the frame rate of the MVRC was comparable to the original VTK ray caster for small and medium-sized datasets but was approximately 3 frames per second slower for large datasets. The MVRC was successfully integrated in an existing surgical navigation system and was shown to be clinically useful during an ultrasound-guided neurosurgical tumor resection. A GPU-based MVRC for VTK is a useful tool in medical visualization. The proposed multi-volume GPU-based ray caster for VTK provided high-quality images at reasonable frame rates. The MVRC was effective when used in a neurosurgical navigation application.

X-Ray Morphological Analysis of the Planck ESZ Clusters

NASA Astrophysics Data System (ADS)

Lovisari, Lorenzo; Forman, William R.; Jones, Christine; Ettori, Stefano; Andrade-Santos, Felipe; Arnaud, Monique; Démoclès, Jessica; Pratt, Gabriel W.; Randall, Scott; Kraft, Ralph

2017-09-01

X-ray observations show that galaxy clusters have a very large range of morphologies. The most disturbed systems, which are good to study how clusters form and grow and to test physical models, may potentially complicate cosmological studies because the cluster mass determination becomes more challenging. Thus, we need to understand the cluster properties of our samples to reduce possible biases. This is complicated by the fact that different experiments may detect different cluster populations. For example, Sunyaev-Zeldovich (SZ) selected cluster samples have been found to include a greater fraction of disturbed systems than X-ray selected samples. In this paper we determine eight morphological parameters for the Planck Early Sunyaev-Zeldovich (ESZ) objects observed with XMM-Newton. We found that two parameters, concentration and centroid shift, are the best to distinguish between relaxed and disturbed systems. For each parameter we provide the values that allow selecting the most relaxed or most disturbed objects from a sample. We found that there is no mass dependence on the cluster dynamical state. By comparing our results with what was obtained with REXCESS clusters, we also confirm that the ESZ clusters indeed tend to be more disturbed, as found by previous studies.