Sample records for wavelength dispersive x-ray

  1. A multi-crystal wavelength dispersive x-ray spectrometer

    SciTech Connect

    Alonso-Mori, Roberto; Montanez, Paul; Delor, James; Bergmann, Uwe [LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Kern, Jan [LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720-8099 (United States); Sokaras, Dimosthenis; Weng, Tsu-Chien; Nordlund, Dennis [SSRL, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Tran, Rosalie; Yachandra, Vittal K.; Yano, Junko [Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720-8099 (United States)

    2012-07-15

    A multi-crystal wavelength dispersive hard x-ray spectrometer with high-energy resolution and large solid angle collection is described. The instrument is specifically designed for time-resolved applications of x-ray emission spectroscopy (XES) and x-ray Raman scattering (XRS) at X-ray Free Electron Lasers (XFEL) and synchrotron radiation facilities. It also simplifies resonant inelastic x-ray scattering (RIXS) studies of the whole 2d RIXS plane. The spectrometer is based on the Von Hamos geometry. This dispersive setup enables an XES or XRS spectrum to be measured in a single-shot mode, overcoming the scanning needs of the Rowland circle spectrometers. In conjunction with the XFEL temporal profile and high-flux, it is a powerful tool for studying the dynamics of time-dependent systems. Photo-induced processes and fast catalytic reaction kinetics, ranging from femtoseconds to milliseconds, will be resolvable in a wide array of systems circumventing radiation damage.

  2. A multi-crystal wavelength dispersive x-ray spectrometer

    PubMed Central

    Alonso-Mori, Roberto; Kern, Jan; Sokaras, Dimosthenis; Weng, Tsu-Chien; Nordlund, Dennis; Tran, Rosalie; Montanez, Paul; Delor, James; Yachandra, Vittal K.; Yano, Junko; Bergmann, Uwe

    2012-01-01

    A multi-crystal wavelength dispersive hard x-ray spectrometer with high-energy resolution and large solid angle collection is described. The instrument is specifically designed for time-resolved applications of x-ray emission spectroscopy (XES) and x-ray Raman scattering (XRS) at X-ray Free Electron Lasers (XFEL) and synchrotron radiation facilities. It also simplifies resonant inelastic x-ray scattering (RIXS) studies of the whole 2d RIXS plane. The spectrometer is based on the Von Hamos geometry. This dispersive setup enables an XES or XRS spectrum to be measured in a single-shot mode, overcoming the scanning needs of the Rowland circle spectrometers. In conjunction with the XFEL temporal profile and high-flux, it is a powerful tool for studying the dynamics of time-dependent systems. Photo-induced processes and fast catalytic reaction kinetics, ranging from femtoseconds to milliseconds, will be resolvable in a wide array of systems circumventing radiation damage. PMID:22852678

  3. Wavelength dispersive analysis with the synchrotron x ray fluorescence microprobe

    NASA Technical Reports Server (NTRS)

    Rivers, M. L.; Thorn, K. S.; Sutton, S. R.; Jones, K. W.; Bajt, S.

    1993-01-01

    A wavelength dispersive spectrometer (WDS) was tested on the synchrotron x ray fluorescence microprobe at Brookhaven National Laboratory. Compared to WDS spectra using an electron microprobe, the synchrotron WDS spectra have much better sensitivity and, due to the absence of bremsstrahlung radiation, lower backgrounds. The WDS spectrometer was successfully used to resolve REE L fluorescence spectra from standard glasses and transition metal K fluorescence spectra from kamacite.

  4. 12.141 Electron Microprobe Analysis by Wavelength Dispersive X-ray Spectrometry, January (IAP) 2006

    E-print Network

    Chatterjee, Nilanjan

    Introduction to the theory of x-ray microanalysis through the electron microprobe including ZAF matrix corrections. Techniques to be discussed are wavelength and energy dispersive spectrometry, scanning backscattered ...

  5. High gain, Fast Scan, Broad Spectrum Parallel Beam Wavelength Dispersive X-ray Spectrometer for SEM

    SciTech Connect

    OHara, David

    2009-05-08

    During contract # DE-FG02-ER83545, Parallax Research, Inc. developed a High gain, Fast Scan Broad Spectrum Parallel beam Wavelength Dispersive X-ray Spectrometer for use on Scanning Electron Microscopes (SEM). This new spectrometer allows very fast high resolution elemental analysis of samples in an electron microscope. By comparison to previous WDS spectrometers, it can change from one energy position to another very quickly and has an extended range compared to some similar products.

  6. Wavelength dispersing devices for soft and ultrasoft x-ray spectrometers

    SciTech Connect

    Arai, Tomoya; Ryon, R.W.; Shoji, Takashi

    1984-01-01

    Monochromatization combining total reflection by a selected mirror and an appropriate filter offered an alternative approach in order to increase measurable intensity with reasonable spectral resolution. Recently, the use of synthetic multilayers, which are prepared by sputter/evaporation techniques, has been introduced for the detection of soft and ultrasoft x-rays. Studies on the use of these new wavelength dispersing devices have been conducted and it has been found that the reflectivity of these devices is very high compared with single crystals and soap multilayers and that their resolving power is fairly good. This report makes comparisons regarding efficiency of reflection, resolving power and x-ray analytical problems for practical applications among long spacing single crystals, soap multilayers, total reflection combined with a selected mirror and filtering and synthetic multilayers. The x-ray analytical capablities are shown based upon a standard x-ray fluorescence spectrometer equipped with a sealed-off x-ray tube and a gas flow proportional counter with thin film detector window.

  7. Monochromatic wavelength dispersive x-ray fluorescence providing sensitive and selective detection of uranium

    SciTech Connect

    Havrilla, George J [Los Alamos National Laboratory; Collins, Michael L [Los Alamos National Laboratory; Montoya, Velma M [Los Alamos National Laboratory; Chen, Zewu [XOS; Wei, Fuzhong [XOS

    2010-01-01

    Monochromatic wavelength dispersive X-ray fluorescence (MWDXRF) is a sensitive and selective method for elemental compositional analyses. The basis for this instrumental advance is the doubly curved crystal (DCC) optic. Previous work has demonstrated the feasibility of sensitive trace element detection for yttrium as a surrogate for curium in aqueous solutions. Additional measurements have demonstrated similar sensitivity in several different matrix environments which attests to the selectivity of the DCC optic as well as the capabilities of the MWDXRF concept. The objective of this effort is to develop an improved Pu characterization method for nuclear fuel reprocessing plants. The MWDXRF prototype instrument is the second step in a multi-year effort to achieve an improved Pu assay. This work will describe a prototype MWDXRF instrument designed for uranium detection and characterization. The prototype consists of an X-ray tube with a rhodium anode and a DCC excitation optic incorporated into the source. The DCC optic passes the RhK{alpha} line at 20.214 keV for monochromatic excitation of the sample. The source is capable of 50 W power at 50 kV and 1.0 mA operation. The x-ray emission from the sample is collected by a DCC optic set at the UL{alpha} line of 13.613 keV. The collection optic transmits the UL{alpha} x-rays to the silicon drift detector. The x-ray source, sample, collection optic and detector are all mounted on motion controlled stages for the critical alignment of these components. The sensitivity and selectivity of the instrument is obtained through the monochromatic excitation and the monochromatic detection. The prototype instrument performance has a demonstrated for sensitivity for uranium detection of around 2 ppm at the current state of development. Further improvement in sensitivity is expected with more detailed alignment.

  8. DEVELOPMENT, DESIGN, AND OPERATION OF A CASCADE IMPACTOR TO COLLECT AEROSOL SAMPLES FOR WAVELENGTH DISPERSIVE X-RAY FLUORESCENCE ANALYSIS

    EPA Science Inventory

    The goal of this research project was to design and construct a particle sizing device that will collect and size source emitted aerosols on 47 mm diameter substrates for subsequent wavelength dispersive x-ray fluorescence analysis. Calibration studies were conducted with a proto...

  9. Quick X-Ray Reflectometry in the Simultaneous Multiple Angle-Wavelength Dispersive Mode

    NASA Astrophysics Data System (ADS)

    Arakawa, E.; Voegeli, W.; Matsushita, T.; Yano, Y. F.; Hatano, T.

    2013-03-01

    The whole profile of the specular X-ray reflectivity curve was simultaneously and quickly measured with no need to rotate the specimen, the detector or the monochromator crystal. A white synchrotron beam from a bending magnet source is incident on a bent-twisted silicon (111) crystal polychromator that produces a convergent X-ray beam with a continuously varying wavelength (energy) and glancing angle to the specimen surface. This convergent X-ray beam was specularly reflected in the vertical direction by the specimen placed at the focus. The normalized spatial distribution across the beam direction of the reflected beam represents a specular X-ray reflectivity curve because each position along the line recorded on the two dimensional detector surface corresponds to a different momentum transfer. Reflectivity curves from a (001) silicon wafer, a nickel thin film on a silicon substrate, and a water surface were measured with data collection times of 0.001-100 s, 0.01-100 s, and 1.0-1000 s, respectively. The simultaneously covered momentum transfer range was 0.03-0.52 Å-1 for solid specimens and 0-0.41 Å-1 for liquid specimen.

  10. Evaluation on the stability of Hg in ABS disk CRM during measurements by wavelength dispersive X-ray fluorescence spectrometry.

    PubMed

    Ohata, Masaki; Kidokoro, Toshihiro; Hioki, Akiharu

    2012-01-01

    The stability of Hg in an acrylonitrile-butadiene-styrene disk certified reference material (ABS disk CRM, NMIJ CRM 8116-a) during measurements by wavelength dispersion X-ray fluorescence (WD-XRF) analysis was evaluated in this study. The XRF intensities of Hg (L(?)) and Pb (L(?)) as well as the XRF intensity ratios of Hg (L(?))/Pb (L(?)) observed under different X-ray tube current conditions as well as their irradiation time were examined to evaluate the stability of Hg in the ABS disk CRM. The observed XRF intensities and the XRF intensity ratios for up to 32 h of measurements under 80 mA of X-ray tube current condition were constant, even though the surface of the ABS disk CRM was charred by the X-ray irradiation with high current for a long time. Moreover, the measurements on Hg and Pb in the charred disks by an energy dispersive XRF (ED-XRF) spectrometer showed constant XRF intensity ratios of Hg (L(?))/Pb (L(?)). From these results, Hg in the ABS disk CRM was evaluated to be sufficiently stable for XRF analysis. PMID:23149612

  11. 12.141 Electron Microprobe Analysis by Wavelength Dispersive X-ray Spectrometry, January IAP 2010

    E-print Network

    Chatterjee, Nilanjan

    2010-01-01

    This lab-oriented course introduces the student to the subject of X-ray spectrometry and micro-scale chemical quantitative analysis of solid samples through an intensive series of hands-on laboratory exercises that use the ...

  12. High Gain, Fast Scan, Broad Spectrum, Parallel Beam Wavelength Dispersive X-ray Spectrometer for SEM

    SciTech Connect

    David OHara; Dr. Eric Lochmer

    2003-09-12

    Parallax Research, Inc. proposes to produce a new type of x-ray spectrometer for use with Scanning Electron Microscopy (SEM) that would have the energy resolution of WDS and the ease of use of EDS with sufficient gain for lower energies that it can be used at low beam currents as is EDS. Parallax proposes to do this by development of new multiple reflection x-ray collimation optics, new diffractor technology, new detector technology and new scan algorithms.

  13. Wavelength dispersive X-ray fluorescence analysis using fundamental parameter approach of Catha edulis and other related plant samples

    NASA Astrophysics Data System (ADS)

    Shaltout, Abdallah A.; Moharram, Mohammed A.; Mostafa, Nasser Y.

    2012-01-01

    This work is the first attempt to quantify trace elements in the Catha edulis plant (Khat) with a fundamental parameter approach. C. edulis is a famous drug plant in east Africa and Arabian Peninsula. We have previously confirmed that hydroxyapatite represents one of the main inorganic compounds in the leaves and stalks of C. edulis. Comparable plant leaves from basil, mint and green tea were included in the present investigation as well as trifolium leaves were included as a non-related plant. The elemental analyses of the plants were done by Wavelength Dispersive X-Ray Fluorescence (WDXRF) spectroscopy. Standard-less quantitative WDXRF analysis was carried out based on the fundamental parameter approaches. According to the standard-less analysis algorithms, there is an essential need for an accurate determination of the amount of organic material in the sample. A new approach, based on the differential thermal analysis, was successfully used for the organic material determination. The obtained results based on this approach were in a good agreement with the commonly used methods. Depending on the developed method, quantitative analysis results of eighteen elements including; Al, Br, Ca, Cl, Cu, Fe, K, Na, Ni, Mg, Mn, P, Rb, S, Si, Sr, Ti and Zn were obtained for each plant. The results of the certified reference materials of green tea (NCSZC73014, China National Analysis Center for Iron and Steel, Beijing, China) confirmed the validity of the proposed method.

  14. [Simple analytical method of bromine in fruits and grain products with wavelength dispersive X-ray fluorescence spectrometer].

    PubMed

    Tateishi, Yukinari; Hashimoto, Tsuneo; Ushiyama, Keiko; Sakai, Naoko; Baba, Itoko; Nagayama, Toshihiro

    2010-01-01

    A simple analytical method was developed for the determination of total bromine in fruits and grain products by means of wavelength dispersive X-ray fluorescence spectrometry (WDXRF).Five gram samples of fresh fruits, frozen fruits, dried fruits and grain products were extracted with distilled water twice and diluted to 25 mL with distilled water. The sample solution (0.5 mL) was dripped onto the filter paper, which was dried and analyzed by WDXRF. The working curve was linear in the range of 0 to 10 microg/mL. Recoveries at the level of 5 microg/g were 76-104%. The detection limit was 0.5 microg/g and the determination limit was 1.5 microg/g in foods. Compared to the GC-ECD method, this method gave equivalent results for fresh fruits, frozen fruits and grain products. In addition, some dried fruits, in which a slightly high level was detected, gave almost the same results with the GC-ECD method. Therefore, this method is considered to be available as an alternative to the GC-ECD method. PMID:20453454

  15. A simultaneous multiple angle-wavelength dispersive X-ray reflectometer using a bent-twisted polychromator crystal.

    PubMed

    Matsushita, Tadashi; Arakawa, Etsuo; Voegeli, Wolfgang; Yano, Yohko F

    2013-01-01

    An X-ray reflectometer has been developed, which can simultaneously measure the whole specular X-ray reflectivity curve with no need for rotation of the sample, detector or monochromator crystal during the measurement. A bent-twisted crystal polychromator is used to realise a convergent X-ray beam which has continuously varying energy E (wavelength ?) and glancing angle ? to the sample surface as a function of horizontal direction. This convergent beam is reflected in the vertical direction by the sample placed horizontally at the focus and then diverges horizontally and vertically. The normalized intensity distribution of the reflected beam measured downstream of the specimen with a two-dimensional pixel array detector (PILATUS 100K) represents the reflectivity curve. Specular X-ray reflectivity curves were measured from a commercially available silicon (100) wafer, a thin gold film coated on a silicon single-crystal substrate and the surface of liquid ethylene glycol with data collection times of 0.01 to 1000?s using synchrotron radiation from a bending-magnet source of a 6.5?GeV electron storage ring. A typical value of the simultaneously covered range of the momentum transfer was 0.01-0.45?Å(-1) for the silicon wafer sample. The potential of this reflectometer for time-resolved X-ray studies of irreversible structural changes is discussed. PMID:23254659

  16. Multielemental analysis of dried residue from metal-bearing waters by wavelength dispersive X-ray fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Gonzalez-Fernandez, Oscar; Margui, Eva; Queralt, Ignacio

    2009-02-01

    The purpose of this work was evaluation of instrumental sensitivity and detection limits for determination of elemental composition (20 different elements ranging from Na to Pb) of liquid mining samples by using conventional Wavelength Dispersive X-Ray Fluorescence (WDXRF) instrumentation. Preconcentration of elements from liquid samples was performed by means of a simple dried residue process, and spectral evaluation was carried out by integration of the peak area (using WinQXAS/AXIL package software, International Atomic Energy Agency (IAEA)) instead of the common net peak line intensity traditionally used in conventional WDXRF systems. With the proposed methodology, the calculated detection limits were in the µg L - 1 range (from 0.005 to 0.1 mg L - 1 level depending on the element) in all cases, which is suitable for element determination in most liquid samples involved in environmental studies such as metal mining liquid effluents. The detection limits are also below the established limits of the TCLP 1311 (United States Environmental Protection Agency (US-EPA)) and DIN 38414-S4 (German Standard legislation) procedures, which are commonly used to evaluate the leaching of metals from landfill disposal. Accuracy of the procedure was confirmed by analysis, based on the German Standard Method DIN 3814-S4, of water lixiviates from three overbank sediment samples collected in two abandoned mining areas. The attained results were compared with those obtained by inductively coupled plasma (ICP) techniques, and acceptable agreement for elements with Z > 20 was found. This study highlights the possibility of using a simple methodology for analysis of liquid mining samples using the WDXRF technique, commonly employed for geochemical exploration of solid samples in environmental studies.

  17. Soft x-ray beamsplitters and highly dispersive multilayer mirrors for use as soft x-ray laser cavity components

    Microsoft Academic Search

    A. M. Hawryluk; N. M. Ceglio; D. G. Stearns; K. Danzmann; M. Kuehne; P. Muller; B. Wende

    1987-01-01

    The demonstration of amplified spontaneous emission at soft x-ray wavelengths has highlighted the need for normal incidence optics for soft x-rays. Specifically, x-ray laser cavity components will be needed to further advances in x-ray laser research. In this paper, we present the fabrication, characterization and analysis of two possible cavity components, an x-ray beamsplitter and a highly dispersive multilayer mirror.

  18. Fabrication of high-throughput critical-angle X-ray transmission gratings for wavelength-dispersive spectroscopy

    E-print Network

    Bruccoleri, Alexander Robert

    2013-01-01

    The development of the critical-angle transmission (CAT) grating seeks both an order of magnitude improvement in the effective area, and a factor of three increase in the resolving power of future space-based, soft x-ray ...

  19. A simple method for detection of gunshot residue particles from hands, hair, face, and clothing using scanning electron microscopy/wavelength dispersive X-ray (SEM/WDX).

    PubMed

    Kage, S; Kudo, K; Kaizoji, A; Ryumoto, J; Ikeda, H; Ikeda, N

    2001-07-01

    We devised a simple and rapid method for detection of gunshot residue (GSR) particles, using scanning electron microscopy/wavelength dispersive X-ray (SEM/WDX) analysis. Experiments were done on samples containing GSR particles obtained from hands, hair, face, and clothing, using double-sided adhesive coated aluminum stubs (tape-lift method). SEM/WDX analyses for GSR were carried out in three steps: the first step was map analysis for barium (Ba) to search for GSR particles from lead styphnate primed ammunition, or tin (Sn) to search for GSR particles from mercury fulminate primed ammunition. The second step was determination of the location of GSR particles by X-ray imaging of Ba or Sn at a magnification of x 1000-2000 in the SEM, using data of map analysis, and the third step was identification of GSR particles, using WDX spectrometers. Analysis of samples from each primer of a stub took about 3 h. Practical applications were shown for utility of this method. PMID:11451063

  20. Simultaneous detection of electronic structure changes from two elements of a bifunctional catalyst using wavelength-dispersive X-ray emission spectroscopy and in situ electrochemistry.

    PubMed

    Gul, Sheraz; Ng, Jia Wei Desmond; Alonso-Mori, Roberto; Kern, Jan; Sokaras, Dimosthenis; Anzenberg, Eitan; Lassalle-Kaiser, Benedikt; Gorlin, Yelena; Weng, Tsu-Chien; Zwart, Petrus H; Zhang, Jin Z; Bergmann, Uwe; Yachandra, Vittal K; Jaramillo, Thomas F; Yano, Junko

    2015-04-14

    Multielectron catalytic reactions, such as water oxidation, nitrogen reduction, or hydrogen production in enzymes and inorganic catalysts often involve multimetallic clusters. In these systems, the reaction takes place between metals or metals and ligands to facilitate charge transfer, bond formation/breaking, substrate binding, and release of products. In this study, we present a method to detect X-ray emission signals from multiple elements simultaneously, which allows for the study of charge transfer and the sequential chemistry occurring between elements. K? X-ray emission spectroscopy (XES) probes charge and spin states of metals as well as their ligand environment. A wavelength-dispersive spectrometer based on the von Hamos geometry was used to disperse K? signals of multiple elements onto a position detector, enabling an XES spectrum to be measured in a single-shot mode. This overcomes the scanning needs of the scanning spectrometers, providing data free from temporal and normalization errors and therefore ideal to follow sequential chemistry at multiple sites. We have applied this method to study MnOx-based bifunctional electrocatalysts for the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR). In particular, we investigated the effects of adding a secondary element, Ni, to form MnNiOx and its impact on the chemical states and catalytic activity, by tracking the redox characteristics of each element upon sweeping the electrode potential. The detection scheme we describe here is general and can be applied to time-resolved studies of materials consisting of multiple elements, to follow the dynamics of catalytic and electron transfer reactions. PMID:25747045

  1. Field-Portable Non-Destructive Analysis of Lithic Archaeological Samples by X-Ray Fluorescence Instrumentation using a Mercury Iodide Detector: Comparison with Wavelength-Dispersive XRF and a Case Study in British Stone Axe Provenancing

    Microsoft Academic Search

    Olwen Williams-Thorpe; Philip J. Potts; Peter C. Webb

    1999-01-01

    Field-portable X-ray fluorescence (PXRF) instrumentation incorporating three radioisotope sources and a mercury (II) iodide detector has been evaluated in the non-destructive quantitative chemical analysis of lithic artefacts of archaeological interest. The method was tested by comparing PXRF analyses of 19 archaeological samples of fine- to medium-grained igneous rocks with laboratory wavelength-dispersive whole-rock XRF analyses of the same samples. Elements determined

  2. Dispersive XAFS Image Radiograph by Parametric X-ray Radiation

    SciTech Connect

    Mori, Akira; Kobayashi, Koji; Ohshima, Hisashi [Pharmacy, Nihon University, Narashinodai, Funabashi, Chiba, 274-8555 (Japan); Hayakawa, Yasushi; Sato, Isamu; Tanaka, Toshinari; Hayakawa, Ken; Kuwada, Takao [Laboratory for Electron Beam Research and Application, Nihon University, Narashinodai, Funabashi, Chiba, 274-8501 (Japan)

    2007-01-19

    The parametric X-ray (PXR) generator system at Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University is a variable-wavelength and quasi-monochromatic X-ray source, which was developed as one of the advance applications of the 125-MeV electron linear accelerator. Since the first observation of the X-rays generated by the system in April 2004, application studies have been performed using the PXR beam in the region from 6.0 to 20keV. The PXR beam extracted from the fixed output port of the generator has characteristic energy dispersion. The theoretical energy spread at the output port with an inner diameter of 98mm changes approximately from 300eV to 2keV depending on central X-ray energy from 7keV and 20keV. The dispersion occurs linearly only in horizontal direction, with a high energy resolution. The characteristics of the PXR beam from the generator suggest a possibility of for the kind of energy dispersive X-ray absorption fine structure (DXAFS) measurement using density distribution in the radiographs of materials. Using the uniform film of the sample materials, DXAFS can be deduced from the measurement of the horizontal density distribution in the radiograph due to the characteristics of the PXR beam. Since the PXR generator system is based on the S-band liner accelerator, it has the potential for the time-resolved XAFS measurement with several ten pico-second resolutions.

  3. Spatiotemporal focusing dynamics in plasmas at X-ray wavelength

    SciTech Connect

    Sharma, A., E-mail: a-physics2001@yahoo.com; Tibai, Z. [Institute of Physics, University of Pecs, Pecs–7624 (Hungary)] [Institute of Physics, University of Pecs, Pecs–7624 (Hungary); Hebling, J. [Institute of Physics, University of Pecs, Pecs–7624 (Hungary) [Institute of Physics, University of Pecs, Pecs–7624 (Hungary); Szentagothai Research Centre, University of Pecs, Pecs-7624 (Hungary); Mishra, S. K. [Institute for Plasma Research, Gandhinagar (India)] [Institute for Plasma Research, Gandhinagar (India)

    2014-03-15

    Using a finite curvature beam, we investigate here the spatiotemporal focusing dynamics of a laser pulse in plasmas at X-ray wavelength. We trace the dependence of curvature parameter on the focusing of laser pulse and recognize that the self-focusing in plasma is more intense for the X-ray laser pulse with curved wavefront than with flat wavefront. The simulation results demonstrate that spatiotemporal focusing dynamics in plasmas can be controlled with the appropriate choice of beam-plasma parameters to explore the high intensity effects in X-ray regime.

  4. Large area quantitative X-ray mapping of (U,Pu)O 2 nuclear fuel pellets using wavelength dispersive electron probe microanalysis

    NASA Astrophysics Data System (ADS)

    Brémier, S.; Haas, D.; Somers, J.; Walker, C. T.

    2003-04-01

    The work presented is an example of how large area compositional mapping (?1 mm 2) can be used to provide quantitative information on element distribution and specimen homogeneity. High-resolution was accomplished by producing a collage of X-ray maps acquired using classical conditions; magnification ×400, spatial resolution 256×256 pixels. The individual images, each measuring roughly 250×250 ?m, were converted to quantitative maps using the HIMAX® software package and the XMAS® matrix correction from SAMx. The quantitative gray-level large area X-ray picture was pieced together using the 'Multiple Image Alignment' function of the ANALYSIS® image processing software. This software was also used to convert the gray-level pictures to false color images. The specimens investigated were transverse sections of MOX fuel pellets. Results are presented for the distribution of Pu by area fraction and cumulative area fraction, the size distribution of regions of high Pu concentration and average separation of these regions.

  5. Site-specific Incorporation of 3-Iodo-L-tyrosine into Proteins and Single-wavelength Anomalous Dispersion Phasing with Soft X-ray in Protein Crystallography

    NASA Astrophysics Data System (ADS)

    Murayama, Kazutaka; Sakamoto, Kensaku

    Iodine is a good anomalous scatter for radiations from in-house X-ray generators (Cu/CrK?). Non-natural amino acid, 3-iodo-L-tyrosine, is able to be site-specifically incorporated into proteins with amber suppresser tRNA and mutated TyrRS from M. jannaschii in the E. coli expression system. To determine the crystal structure of acetyl transferase from T. thermophilus, iodotyrosine-containing proteins were prepared and crystallized. Structure determination was successfully conducted with the protein variant with iodotyrosine at position 111. Anomalous signals from iodotyrosine with Cu/CrK? radiations were both sufficient to calculate clear electron density map. In the crystal structure, iodotyrosine did not significantly disturb the native structure.

  6. X-ray Beamlines On A Superconducting Wavelength Shifter

    SciTech Connect

    Song, Y.F.; Chang, C.H.; Liu, C.Y.; Huang, L.J.; Chang, S.H.; Chuang, J.M.; Chung, S.C.; Tseng, P.C.; Lee, J.F.; Tsang, K.L.; Liang, K.S. [National Synchrotron Radiation Research Center, Hsinchu 30077, Taiwan (China)

    2004-05-12

    A Superconducting Wavelength Shifter (SWLS) insertion device with peak field of 6 Tesla has been installed in the Taiwan Light Source (TLS) storage ring to increase the critical energy of the radiation spectrum from 2 keV to 9 keV. We are constructing three hard X-ray beamlines BL01A, BL01B and BL01C to utilize the photon source generated by this insertion device. The beamline BL01B is a DCM X-ray beamline with a toroidal focusing mirror, which provides monochromatic photon beams with energies from 5 keV to 20 keV for X-ray scattering experiments. At the sample position, the expected photon flux is about 7x1011 photon/sec/200mA with an average energy resolution ({delta}E/E) of 1x10-3 and the focused beam size is about 1 mm x 0.4 mm. The beamline BL01C is a standard DCM X-ray beamline with both collimating and focusing mirrors, which will deliver monochromatic photon beams with energy ranging from 6 keV to 33 keV for EXAFS and powder diffraction. At the sample position, the expected photon flux is 1x1011 photon/sec /200mA with an average energy resolution ({delta}E/E) of 1.6x10-4 and the focused beam size is about 0.9 mm x 0.2 mm. The beamline BL01A is a white-light beamline reserved for other applications. Both BL01A and BL01B beamlines have been constructed and are in commissioning. An average photon flux of 3x1011 photon/sec has been obtained at beamline BL01B.

  7. The use of wavelength dispersive X-ray fluorescence and discriminant analysis in the identification of the elemental composition of cumin samples and the determination of the country of origin.

    PubMed

    Hondrogiannis, E; Peterson, K; Zapf, C M; Roy, W; Blackney, B; Dailey, K

    2012-12-15

    Sixteen elements found in 33 cumin spice samples from China, India, Syria, and Turkey were analysed by wavelength dispersive X-ray fluorescence (WDXRF) spectroscopy using the commercially available Bruker - AXS S4 Explorer for the purpose of using the elements to discriminate among country of origin. Pellets were prepared of the samples and elemental concentrations calculated from calibration curves constructed using four National Institute of Standards and Technology (NIST) standards. A separate NIST tomato standard (1573a) was used as a validation check, while the WDXRF data for six of the cumin samples was further validated using inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The elements measured included Ca, Mg, K, P, S, Al, Ba, Br, Cl, Fe, Na, Mn, Rb, Sr, Cu, and Zn and were detected in the range from an average mean of 4.3 mg kg(-1) for Ba up to 19223.8 mg kg(-1) for K. Analysis of variance (ANOVA) was used to determine which elemental concentrations were statistically different from one another, and discriminant analysis was used to classify the cumin samples by country of origin. Using only eight elements (Ca, Mg, K, Fe, Na, Mn, Sr, and Zn) we were able to differentiate among cumin samples from four different geographic origins. Validation of the model with the validation set yielded 87.50% accuracy. Successful discrimination with just eight elements will allow for higher throughput in the screening of cumin samples using WDXRF for origin verification in less time. PMID:22980878

  8. Carbon nanotubes as a solid sorbent for the preconcentration of Cr, Mn, Fe, Co, Ni, Cu, Zn and Pb prior to wavelength-dispersive X-ray fluorescence spectrometry.

    PubMed

    Zawisza, Beata; Skorek, Robert; Stankiewicz, Grazyna; Sitko, Rafal

    2012-09-15

    The preconcentration of trace elements on multiwalled carbon nanotubes (MWCNTs) followed by a wavelength-dispersive X-ray fluorescence analysis (WDXRF) has been investigated. The proposed preconcentration procedure is based on the sorption of trace elements on MWCNTs dispersed in analyzed solution. After sorption, the MWCNTs with the metal ions were collected onto the filter, and then the preconcentrated elements were determined directly by WDXRF. The preconcentration method was optimized, and in consequence, in order to obtain satisfactory recoveries using 100 mL of samples, the sorption process was performed with 1mg of MWCNTs within 5 min. Some conditions of the preconcentration process such as the pH of analyte solution, amounts of MWCNTs, the volume of the sample, the contact time between analytes and MWCNTs (stirring time), and the effects of foreign metals are discussed in detail in the paper. Adsorption onto raw and oxidized MWCNTs was also studied. The proposed procedure allows obtaining the detection limits of 0.6, 0.6, 1.0, 0.7, 0.6, 0.5, 0.9 and 1.9 ng mL(-1) for Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Pb(II), respectively. The recoveries of determined elements were about 100%. Because the analytes are not eluted from the sorbent before WDXRF analysis, the risk of contamination and loss of analytes is reduced to minimum. Moreover, because the samples are analyzed as a thin layer, the matrix effects can be neglected. The proposed preconcentration method using MWCNTs coupled with WDXRF spectrometry was successfully applied to determine trace elements in natural water samples. PMID:22967643

  9. Detection of faint X-ray spectral features using wavelength, energy, and spatial discrimination techniques

    NASA Astrophysics Data System (ADS)

    Hudson, L. T.; Gillaspy, J. D.; Pomeroy, J. M.; Szabo, C. I.; Tan, J. N.; Radics, B.; Takacs, E.; Chantler, C. T.; Kimpton, J. A.; Kinnane, M. N.; Smale, L. F.

    2007-09-01

    We report here our methods and results of measurements of very low-signal X-ray spectra produced by highly charged ions in an electron beam ion trap (EBIT). A megapixel Si charge-coupled device (CCD) camera was used in a direct-detection, single-photon-counting mode to image spectra with a cylindrically bent Ge(2 2 0) crystal spectrometer. The resulting wavelength-dispersed spectra were then processed using several intrinsic features of CCD images and image-analysis techniques. We demonstrate the ability to clearly detect very faint spectral features that are on the order of the noise due to cosmic-ray background signatures in our images. These techniques remove extraneous signal due to muon tracks and other sources, and are coupled with the spectrometer wavelength dispersion and atomic-structure calculations of hydrogen-like Ti to identify the energy of a faint line that was not in evidence before applying the methods outlined here.

  10. High Resolution, Non-Dispersive X-Ray Calorimeter Spectrometers on EBITs and Orbiting Observatories

    NASA Technical Reports Server (NTRS)

    Porter, Frederick S.

    2010-01-01

    X-ray spectroscopy is the primary tool for performing atomic physics with Electron beam ion trap (EBITs). X-ray instruments have generally fallen into two general categories, 1) dispersive instruments with very high spectral resolving powers but limited spectral range, limited count rates, and require an entrance slit, generally, for EBITs, defined by the electron beam itself, and 2) non-dispersive solid-state detectors with much lower spectral resolving powers but that have a broad dynamic range, high count rate ability and do not require a slit. Both of these approaches have compromises that limit the type and efficiency of measurements that can be performed. In 1984 NASA initiated a program to produce a non-dispersive instrument with high spectral resolving power for x-ray astrophysics based on the cryogenic x-ray calorimeter. This program produced the XRS non-dispersive spectrometers on the Astro-E, Astro-E2 (Suzaku) orbiting observatories, the SXS instrument on the Astro-H observatory, and the planned XMS instrument on the International X-ray Observatory. Complimenting these spaceflight programs, a permanent high-resolution x-ray calorimeter spectrometer, the XRS/EBIT, was installed on the LLNL EBIT in 2000. This unique instrument was upgraded to a spectral resolving power of 1000 at 6 keV in 2003 and replaced by a nearly autonomous production-class spectrometer, the EBIT Calorimeter Spectrometer (ECS), in 2007. The ECS spectrometer has a simultaneous bandpass from 0.07 to over 100 keV with a spectral resolving power of 1300 at 6 keV with unit quantum efficiency, and 1900 at 60 keV with a quantum efficiency of 30%. X-ray calorimeters are event based, single photon spectrometers with event time tagging to better than 10 us. We are currently developing a follow-on instrument based on a newer generation of x-ray calorimeters with a spectral resolving power of 3000 at 6 keV, and improved timing and measurement cadence. The unique capabilities of the x-ray calorimeter spectrometer, coupled with higher spectral resolution dispersive spectrometers to resolve line blends, has enabled many science investigations, to date mostly in our x-ray laboratory astrophysics program. These include measurements of absolute cross sections for Land K shell emission from Fe and Ni, charge exchange measurements in many astrophysically abundant elements, lifetime measurements, line ratios, and wavelength measurements. In addition, we have performed many additional measurements in nuclear physics, and in support of diagnostics for laser fusion, for example. In this presentation we will give a detailed overview of x-ray calorimeter instruments in general and in our EBIT laboratory astrophysics program in particular. We will also discuss the science yield of our measurements at EBIT over the last decade) prospects for future science enabled by the current generation of spectrometers and that will be expanded in the near future by the next generation of spectrometers starting in 2611.

  11. The Dispersion of the MIR { Hard X-ray Correlation in AGN

    E-print Network

    Gandhi, Poshak

    The Dispersion of the MIR { Hard X-ray Correlation in AGN Hannes Horst 1;2 , Alain Smette 1:5#22;m IR photometry (MIR) of 8 AGN, obtained with VISIR on the VLT and study the dispersion of the correlation between their MIR and hard X-ray luminosities. The uni#12;ed scenarios predict that hard X

  12. Development of in situ, at-wavelength metrology for soft x-ray nano-focusing

    SciTech Connect

    Yuan, Sheng Sam; Yashchuk, Valeriy V.; Goldberg, Kenneth A.; Celestre, Richard; McKinney, Wayne R.; Morrison, Gregory Y.; Warwick, Tony; Padmore, Howard A.

    2010-09-19

    At the Advanced Light Source (ALS), we are developing broadly applicable, high-accuracy, in situ, at-wavelength wavefront slope measurement techniques for Kirkpatrick-Baez (KB) mirror nano-focusing. We describe here details of the metrology beamline endstation, the at-wavelength tests, and an original alignment method that have already allowed us to precisely set a bendable KB mirror to achieve a FWHM focused spot size of ~;;120 nm, at 1-nm soft x-ray wavelength.

  13. TRANSIT OBSERVATIONS OF THE HOT JUPITER HD 189733b AT X-RAY WAVELENGTHS

    SciTech Connect

    Poppenhaeger, K.; Wolk, S. J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Schmitt, J. H. M. M., E-mail: kpoppenhaeger@cfa.harvard.edu [Hamburger Sternwarte, Gojenbergsweg 112, D-21029 Hamburg (Germany)

    2013-08-10

    We present new X-ray observations obtained with Chandra ACIS-S of the HD 189733 system, consisting of a K-type star orbited by a transiting Hot Jupiter and an M-type stellar companion. We report a detection of the planetary transit in soft X-rays with a significantly deeper transit depth than observed in the optical. The X-ray data favor a transit depth of 6%-8%, versus a broadband optical transit depth of 2.41%. While we are able to exclude several possible stellar origins for this deep transit, additional observations will be necessary to fully exclude the possibility that coronal inhomogeneities influence the result. From the available data, we interpret the deep X-ray transit to be caused by a thin outer planetary atmosphere which is transparent at optical wavelengths, but dense enough to be opaque to X-rays. The X-ray radius appears to be larger than the radius observed at far-UV wavelengths, most likely due to high temperatures in the outer atmosphere at which hydrogen is mostly ionized. We furthermore detect the stellar companion HD 189733B in X-rays for the first time with an X-ray luminosity of log L{sub X} = 26.67 erg s{sup -1}. We show that the magnetic activity level of the companion is at odds with the activity level observed for the planet-hosting primary. The discrepancy may be caused by tidal interaction between the Hot Jupiter and its host star.

  14. Field Emission Scanning Electron Microscopy (FE-SEM) and Energy Dispersive X-Ray (EDX) Spectroscopy

    E-print Network

    Gelfond, Michael

    system with 30 take-off angle for quantitative analysis, digital imaging, and X-ray mapping. The EDAXField Emission Scanning Electron Microscopy (FE-SEM) and Energy Dispersive X-Ray (EDX) Spectroscopy of objective aperture. Dual SE detectors allow versatile imaging. The FE-SEM is equipped with fully digital

  15. At-wavelength metrology of x-ray optics at Diamond Light Source

    NASA Astrophysics Data System (ADS)

    Wang, Hongchang; Berujon, Sebastien; Sutter, John; Alcock, Simon G.; Sawhney, Kawal

    2014-09-01

    Modern, third-generation synchrotron radiation sources provide coherent and extremely bright beams of X-ray radiation. The successful exploitation of such beams depends to a significant extent on imperfections and misalignment of the optics employed on the beamlines. This issue becomes even more critical with the increasing use of active optics, and the desire to achieve diffraction-limited and coherence-preserving X-ray beams. In recent years, significant progress has been made to improve optic testing and optimization techniques, especially those using X-rays for so-called atwavelength metrology. These in-situ and at-wavelength metrology methods can be used not only to optimize the performance of X-ray optics, but also to correct and minimize the collective distortions of upstream beamline optics, including monochromators, and transmission windows. An overview of at-wavelength metrology techniques implemented at Diamond Light Source is presented, including grating interferometry and X-ray near-field speckle based techniques. Representative examples of the application of these techniques are also given, including in-situ and atwavelength calibration and optimization of: active, piezo bimorph mirrors; Kirkpatrick-Baez (KB) mirrors; and refractive optics such as compound refractive lenses.

  16. Accounting for the dispersion in the x ray properties of early-type galaxies

    NASA Technical Reports Server (NTRS)

    White, Raymond E., III; Sarazin, Craig L.

    1990-01-01

    The x ray luminosities of early-type galaxies are correlated with their optical (e.g., blue) luminosities (L sub X approx. L sub B exp 1.6), but the x ray luminosities exhibit considerable scatter for a given optical luminosity L sub B. This dispersion in x ray luminosity is much greater than the dispersion of other properties of early-type galaxies (for a given L sub B), such as luminosity scale-length, velocity dispersion, color, and metallicity. Here, researchers consider several possible sources for the dispersion in x ray luminosity. Some of the scatter in x ray luminosity may result from stellar population variations between galaxies with similar L sub B. Since the x ray emitting gas is from accumulated stellar mass loss, the L sub X dispersion may be due to variations in integrated stellar mass loss rates. Another possible cause of the L sub X dispersion may be variations in the amount of cool material in the galaxies; cool gas may act as an energy sink for the hot gas. Infrared emission may be used to trace such cool material, so researchers look for a correlation between the infrared emission and the x ray emission of early-type galaxies at fixed L sub B. Velocity dispersion variations between galaxies of similar L sub B may also contribute to the L sub X dispersion. The most likely a priori source of the dispersion in L sub X is probably the varying amount of ram-pressure stripping in a range of galaxy environments. The hot gaseous halos of early-type galaxies can be stripped in encounters with other galaxies or with ambient cluster gas if the intracluster gas is sufficiently dense. Researchers find that the most likely cause of dispersion in the x ray properties of early type galaxies is probably the ram-pressure stripping of gaseous halos from galaxies. For a sample of 81 early-type galaxies with x ray luminosities or upper limits derived from Einstein Observatory observations (CFT) researchers calculated the cumulative distribution of angular distances between the x ray sample members and bright galaxies from the Revised Shapley - Ames catalog. Collectively, galaxies with low x ray luminosities (for a given L sub B) tend to be in denser environments than galaxies with higher x ray luminosities.

  17. Wavelength calibration of x-ray imaging crystal spectrometer on Joint Texas Experimental Tokamaka)

    NASA Astrophysics Data System (ADS)

    Yan, W.; Chen, Z. Y.; Jin, W.; Huang, D. W.; Ding, Y. H.; Li, J. C.; Zhang, X. Q.; Lee, S. G.; Shi, Y. J.; Zhuang, G.

    2014-11-01

    The wavelength calibration of x-ray imaging crystal spectrometer is a key issue for the measurements of plasma rotation. For the lack of available standard radiation source near 3.95 Å and there is no other diagnostics to measure the core rotation for inter-calibration, an indirect method by using tokamak plasma itself has been applied on joint Texas experimental tokamak. It is found that the core toroidal rotation velocity is not zero during locked mode phase. This is consistent with the observation of small oscillations on soft x-ray signals and electron cyclotron emission during locked-mode phase.

  18. Rest-wavelength Fiducials for the ITER Core Imaging X-ray Spectrometer

    NASA Technical Reports Server (NTRS)

    Beiersdorfer, P.; Brown, G. V.; Graf, A. T.; Bitter, M.; Hill, K. W.; Kelley, R. L.; Kilbourne, C. A.; Leutenegger, M. A.; Porter, F. S.

    2012-01-01

    Absolute wavelength references are needed to derive the plasma velocities from the Doppler shift of a given line emitted by a moving plasma. We show that such reference standards exist for the strongest x-ray line in neonlike W64+, which has become the line of choice for the ITER (Latin the way) core imaging x-ray spectrometer. Close-by standards are the Hf L3 line and the Ir L2 line, which bracket the W64+ line by 30 eV; other standards are given by the Ir L1 and L2 lines and the Hf L1 and L2 lines, which bracket the W64+ line by 40 and 160 eV, respectively. The reference standards can be produced by an x-ray tube built into the ITER spectrometer. We present spectra of the reference lines obtained with an x-ray microcalorimeter and compare them to spectra of the W64+ line obtained both with an x-ray microcalorimeter and a crystal spectrometer

  19. Rest-wavelength fiducials for the ITER core imaging x-ray spectrometera)

    NASA Astrophysics Data System (ADS)

    Beiersdorfer, P.; Brown, G. V.; Graf, A. T.; Bitter, M.; Hill, K. W.; Kelley, R. L.; Kilbourne, C. A.; Leutenegger, M. A.; Porter, F. S.

    2012-10-01

    Absolute wavelength references are needed to derive the plasma velocities from the Doppler shift of a given line emitted by a moving plasma. We show that such reference standards exist for the strongest x-ray line in neonlike W64+, which has become the line of choice for the ITER (Latin "the way") core imaging x-ray spectrometer. Close-by standards are the Hf L?3 line and the Ir L?2 line, which bracket the W64+ line by ±30 eV; other standards are given by the Ir L?1 and L?2 lines and the Hf L?1 and L?2 lines, which bracket the W64+ line by ±40 and ±160 eV, respectively. The reference standards can be produced by an x-ray tube built into the ITER spectrometer. We present spectra of the reference lines obtained with an x-ray microcalorimeter and compare them to spectra of the W64+ line obtained both with an x-ray microcalorimeter and a crystal spectrometer.

  20. Single photon energy dispersive x-ray diffraction

    SciTech Connect

    Higginbotham, Andrew; Patel, Shamim; Ciricosta, Orlando; Suggit, Matthew J.; Wark, Justin S. [Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom)] [Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Hawreliak, James A.; Collins, Gilbert W.; Coppari, Federica; Eggert, Jon H. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)] [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Tang, Henry [Department of Earth and Planetary Science, University of California Berkeley, Berkeley, California 94720 (United States)] [Department of Earth and Planetary Science, University of California Berkeley, Berkeley, California 94720 (United States)

    2014-03-15

    With the pressure range accessible to laser driven compression experiments on solid material rising rapidly, new challenges in the diagnosis of samples in harsh laser environments are emerging. When driving to TPa pressures (conditions highly relevant to planetary interiors), traditional x-ray diffraction techniques are plagued by increased sources of background and noise, as well as a potential reduction in signal. In this paper we present a new diffraction diagnostic designed to record x-ray diffraction in low signal-to-noise environments. By utilising single photon counting techniques we demonstrate the ability to record diffraction patterns on nanosecond timescales, and subsequently separate, photon-by-photon, signal from background. In doing this, we mitigate many of the issues surrounding the use of high intensity lasers to drive samples to extremes of pressure, allowing for structural information to be obtained in a regime which is currently largely unexplored.

  1. Single photon energy dispersive x-ray diffraction

    NASA Astrophysics Data System (ADS)

    Higginbotham, Andrew; Patel, Shamim; Hawreliak, James A.; Ciricosta, Orlando; Collins, Gilbert W.; Coppari, Federica; Eggert, Jon H.; Suggit, Matthew J.; Tang, Henry; Wark, Justin S.

    2014-03-01

    With the pressure range accessible to laser driven compression experiments on solid material rising rapidly, new challenges in the diagnosis of samples in harsh laser environments are emerging. When driving to TPa pressures (conditions highly relevant to planetary interiors), traditional x-ray diffraction techniques are plagued by increased sources of background and noise, as well as a potential reduction in signal. In this paper we present a new diffraction diagnostic designed to record x-ray diffraction in low signal-to-noise environments. By utilising single photon counting techniques we demonstrate the ability to record diffraction patterns on nanosecond timescales, and subsequently separate, photon-by-photon, signal from background. In doing this, we mitigate many of the issues surrounding the use of high intensity lasers to drive samples to extremes of pressure, allowing for structural information to be obtained in a regime which is currently largely unexplored.

  2. Performance of X-ray Beam lines at Superconducting Wavelength Shifter

    SciTech Connect

    Song, Y. F.; Chang, C. H.; Liu, C. Y.; Chang, S. H.; Jeng, U.; Lai, Y. H.; Liu, D. G.; Yin, G. C.; Lee, J. F.; Sheu, H. S.; Chung, S. C.; Tsang, K. L.; Liang, K. S. [National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan (China); Hwu, Y. [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China)

    2007-01-19

    To fully utilize a hard X-ray source generated by a 5-Tesla superconducting wavelength shifter (SWLS) that shifts the critical energy of synchrotron spectrum from 2.1 to 7.5 keV, we have designed and constructed three hard X-ray beamlines, BL01A, BL01B, and BL0IC. BL01A is a white light beamline for phase-contrast X-ray image applications. The spatial resolution of phase-contrast X-ray image is 1 {mu}m. The photon flux can saturate a camera of 700-microns field-of-view within 10 ms. BL01B equipped with a double crystal monochromator (DCM) and a toroidal focusing mirror, which provides photon beams with energies from 5 to 20 keV, is adequate for scattering related experiments and hard X-ray microscopy. The energy-resolution {delta}E/E is 1 x 10-3. The photon flux is optimized to be 4.5 x 1011 photons s-1 with 200 mA ring current, which outcasts the flux of the wiggler beamline BL17B by 110 times at 15 keV. BL01C equipped with a DCM and both collimating and focusing mirrors, covering photon energies from 6 to 33 keV, is ideal for EXAFS and X-ray diffraction (XRD) experiments. The average photon flux is 3 x 1010 photons s-1 with 200 mA ring current. The energy-resolution is between 1.7 x 10-4 and 3.0 x 10-4. In this article, we will present the measured performance of these beamlines.

  3. Demonstration of guided-wave phenomena at extreme-ultraviolet and soft-x-ray wavelengths

    Microsoft Academic Search

    Natale M. Ceglio; A. M. Hawryluk; D. G. Stearns; M. Kuehne; P. Muller

    1988-01-01

    We report an explicit demonstration of classical guided-wave propagation at XUV and soft-x-ray wavelengths. Experiments were performed using narrow-band synchrotron radiation at 5, 20.8, 21, and 30 nm. Free-standing gold transmission gratings served as waveguide structures. These structures had a 300-nm grating period with waveguide channel widths as small as 100 nm and were as thick as 700 nm in

  4. Demonstration of guided-wave phenomena at extreme-ultraviolet and soft-X-ray wavelengths

    Microsoft Academic Search

    N. M. Ceglio; A. M. Hawryluk; D. G. Stearns; M. Kuehne; P. Mueller

    1988-01-01

    An explicit demonstration of classical guided-wave propagation at XUV and soft-X-ray wavelengths is presented. Experiments were performed using narrow-band synchrotron radiation at 5, 20.8, 21, and 30 nm. Free-standing gold transmission gratings served as waveguide structures. These structures had a 300-nm grating period with waveguide channel widths as small as 100 nm, and were as thick as 700 nm in

  5. Unveiling the multi-wavelength phenomenology of Anomalous X-ray Pulsars

    E-print Network

    GianLuca Israel; Luigi Stella; Stefano Covino; Sergio Campana; Lorella Angelini; Roberto Mignani; Sandro Mereghetti; Gianni Marconi; Rosalba Perna

    2003-10-17

    During 2002-2003 the number of IR-identified counterparts to the Anomalous X-ray Pulsars (AXPs) has grown to four (4U0142+614, 2E2259+584, 1E 1048-59 and 1RXS J170849-400910) out of the six assessed objects of this class, plus two candidates. More importantly, some new common observational characteristics have been identified, such as the IR variability, the IR flattening in the broad band energy spectrum, the X-ray spectral variability as a function of pulse phase (which are not predicted by the magnetar model), and the SGR-like bursts (which can not be explained in terms of standard accretion models). We present the results obtained from an extensive multi-wavelength observational campaign carried out collecting data from the NTT, CFHT for the optical/IR bands, and XMM, Chandra (plus BeppoSAX archival data) in the X-rays. Based on these results and those reported in the literature, the IR-to-X-ray band emission of AXPs has been compared and studied.

  6. X-Ray and Multi-Wavelength Observations of Gamma Ray Bursts (GRBs)

    NASA Technical Reports Server (NTRS)

    Kouveliotou, Chryssa

    2009-01-01

    The launch of the Italian (with Dutch participation) satellite BeppoSAX in 1996 enabled the detection of the first X-ray GRB afterglow, which in turn led to GRB counterpart detection in multiple wavelengths. This breakthrough firmly established the cosmological nature of GRBs. However, afterglow observations of GRBs took off in large numbers after the launch of NASA's Swift satellite in 2004. Swift enabled multiple major discoveries, such as the early lightcurves of X-ray afterglows, the first detection of a short GRB afterglow and opened more questions such as where are the elusive breaks in afterglow light curves. I will describe here these results and will discuss future opportunities and improvements in the field.

  7. At-wavelength metrology using the X-ray speckle tracking technique: case study of a X-ray compound refractive lens

    NASA Astrophysics Data System (ADS)

    Berujon, S.; Wang, H.; Sawhney, K. J. S.

    2013-03-01

    The X-ray speckle tracking technique has been established on the Test beamline B16 at Diamond and is being used as a valuable tool for at-wavelength metrology. We show here the possibilities and the achievable performances of the X-ray Speckle Tracking technique for optics characterization: the description is illustrated with the case study of the characterization of a compound refractive lens. This optical element was characterized online using the speckle tracking method with nanoradian accuracy and micrometer spatial resolution. For discussion purpose, the results are compared to the ones obtained under similar conditions using a grating interferometer.

  8. X-ray photoemission and energy dispersive spectroscopy of hydroxyapatite-coated titanium

    SciTech Connect

    Drummond, J.L.; Steinberg, A.D. [Univ. of Illinois, Chicago, IL (United States). Coll. of Dentistry; Krauss, A.R. [Argonne National Lab., IL (United States)

    1997-07-01

    The purpose of this study was to determine the chemical composition changes of hydroxyapatite (HA) coated titanium using surface analysis (X-ray photoemission) and bulk analysis (energy dispersive spectroscopy). The specimens examined were controls and specimens aged 30 min and 3 h at room temperature in distilled water and 0.2M sodium phosphate buffer (pH 7.2). Each X-ray photoemission cycle consisted of three scans followed by argon sputtering for 10 min for usually 20 cycles, corresponding to a sampling depth of {approximately}1,500 {angstrom}. The energy dispersive spectroscopy analysis was on a 110 by 90 {micro}m area for 500 s. The X-ray photoemission results indicated the oxidation effect of water on the titanium (as TiO{sub 2}) and the effect of the buffer to increase the surface concentration of phosphorus. No differences in the chemical composition were observed by energy dispersive spectroscopy analysis.

  9. THE CHANDRA MULTI-WAVELENGTH PROJECT: OPTICAL SPECTROSCOPY AND THE BROADBAND SPECTRAL ENERGY DISTRIBUTIONS OF X-RAY-SELECTED AGNs

    E-print Network

    Trichas, Markos

    From optical spectroscopy of X-ray sources observed as part of the Chandra Multi-wavelength Project (ChaMP), we present redshifts and classifications for a total of 1569 Chandra sources from our targeted spectroscopic ...

  10. Macromolecular X-ray structure determination using weak, single-wavelength anomalous data.

    PubMed

    Bunkóczi, Gábor; McCoy, Airlie J; Echols, Nathaniel; Grosse-Kunstleve, Ralf W; Adams, Paul D; Holton, James M; Read, Randy J; Terwilliger, Thomas C

    2015-02-01

    We describe a likelihood-based method for determining the substructure of anomalously scattering atoms in macromolecular crystals that allows successful structure determination by single-wavelength anomalous diffraction (SAD) X-ray analysis with weak anomalous signal. With the use of partial models and electron density maps in searches for anomalously scattering atoms, testing of alternative values of parameters and parallelized automated model-building, this method has the potential to extend the applicability of the SAD method in challenging cases. PMID:25532136

  11. Comparison of total-reflection X-ray fluorescence, static and portable energy dispersive X-ray fluorescence spectrometers for art and archeometry studies

    Microsoft Academic Search

    M. Ardid; J. L. Ferrero; D. Juanes; J. L. Lluch; C. Roldán

    2004-01-01

    In this paper, a Total-reflection X-ray Fluorescence (TXRF), a static and a portable Energy Dispersive X-ray Fluorescence (EDXRF) spectrometers are described. Both the equipments and the techniques employed in the field of the art and archeometry are compared. Some applications in this area are presented as well. The aim of the work is to know which spectrometer is the best

  12. Development of at-wavelength metrology for x-ray optics at the ALS

    SciTech Connect

    Yashchuk, Valeriy V.; Goldberg, Kenneth A.; Yuan, Sheng; Celestre, Richard; McKinney, Wayne R.; Morrison, Gregory; Warwick, Tony; Padmore, Howard A.

    2010-07-09

    The comprehensive realization of the exciting advantages of new third- and forth-generation synchrotron radiation light sources requires concomitant development of reflecting and diffractive x-ray optics capable of micro- and nano-focusing, brightness preservation, and super high resolution. The fabrication, tuning, and alignment of the optics are impossible without adequate metrology instrumentation, methods, and techniques. While the accuracy of ex situ optical metrology at the Advanced Light Source (ALS) has reached a state-of-the-art level, wavefront control on beamlines is often limited by environmental and systematic alignment factors, and inadequate in situ feedback. At ALS beamline 5.3.1, we are developing broadly applicable, high-accuracy, in situ, at-wavelength wavefront measurement techniques to surpass 100-nrad slope measurement accuracy for Kirkpatrick-Baez (KB) mirrors. The at-wavelength methodology we are developing relies on a series of tests with increasing accuracy and sensitivity. Geometric Hartmann tests, performed with a scanning illuminated sub-aperture determine the wavefront slope across the full mirror aperture. Shearing interferometry techniques use coherent illumination and provide higher sensitivity wavefront measurements. Combining these techniques with high precision optical metrology and experimental methods will enable us to provide in situ setting and alignment of bendable x-ray optics to realize diffraction-limited, sub 50 nm focusing at beamlines. We describe here details of the metrology beamline endstation, the x-ray beam diagnostic system, and original experimental techniques that have already allowed us to precisely set a bendable KB mirror to achieve a focused spot size of 150 nm.

  13. Energy-Dispersive X-Ray Fluorescence Spectrometry: A Long Overdue Addition to the Chemistry Curriculum

    ERIC Educational Resources Information Center

    Palmer, Peter T.

    2011-01-01

    Portable Energy-Dispersive X-Ray Fluorescence (XRF) analyzers have undergone significant improvements over the past decade. Salient advantages of XRF for elemental analysis include minimal sample preparation, multielement analysis capabilities, detection limits in the low parts per million (ppm) range, and analysis times on the order of 1 min.…

  14. Imaging at soft X-ray wavelengths with high-gain microchannel plate detector systems

    NASA Technical Reports Server (NTRS)

    Timothy, J. Gethyn

    1986-01-01

    Multianode microchannel array (MAMA) detector systems with formats of 256 x 1024 pixels and active areas of 6 x 26 mm are now under evaluation at visible, UV and soft X-ray wavelengths. Very-large-format versions of the MAMA detectors with formats of 2048 x 2048 pixels and active areas of 52 x 52 mm are under development for use in the NASA Goddard Space Telescope Imaging Spectrograph (STIS). Open-structure versions of these detectors with Cs I photocathodes can provide a high-resolution imaging capability at EUV and soft X-ray wavelengths and can deliver a maximum count rate from each array in excess of 10 to the 6th counts/s. In addition, these detector systems have the unique capability to determine the arrival time of a detected photon to an accuracy of 100 ns or better. The construction, mode of operation, and performance characteristics of the MAMA detectors are described, and the program for the development of the very-large-format detectors is outlined.

  15. Detector arrays for photometric measurements at soft X-ray, ultraviolet and visible wavelengths

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.; Mount, G. H.; Bybee, R. L.

    1979-01-01

    The construction and modes of operation of the Multi-Anode Microchannel Array (MAMA) detectors are described, and the designs of spectrometers utilizing them are outlined. MAMA consists of a curved microchannel array plate, an opaque photocathode (peak quantum efficiency of 19% at 1216 A), and a multi-anode (either discrete- or coincidence-anode) readout array. Designed for use in instruments on spaceborne telescopes, MAMA can be operated in a windowless configuration in extreme-ultraviolet and soft X-ray wavelengths, or in a sealed configuration at UV and visible wavelengths. Advantages of MAMA include low applied potential (less than 3.0 kV), high gain (greater than 10 to the 6th electrons/pulse), low sensitivity to high-energy charged particles, and immunity to external magnetic fields of less than 500 Gauss

  16. Diffraction peaks restoration and extraction in energy dispersive X-ray diffraction Ferrol Souleza,b,1,

    E-print Network

    Paris-Sud XI, Université de

    Diffraction peaks restoration and extraction in energy dispersive X-ray diffraction Ferréol Souleza to restore energy dispersive X-ray diffraction (EDXRD) spectra and to extract diffraction peaks. It follows. It separates peaks due to the diffraction by crystalline material from a countinuous background. Tested on real

  17. Material specific X-ray imaging using an energy-dispersive pixel detector

    NASA Astrophysics Data System (ADS)

    Egan, Christopher K.; Wilson, Matthew D.; Veale, Matthew C.; Seller, Paul; Jacques, Simon D. M.; Cernik, Robert J.

    2014-04-01

    By imaging the X-ray spectral properties or ‘colours’ we have shown how material specific imaging can be performed. Using a pixelated energy-dispersive X-ray detector we record the absorbed and emitted hard X-radiation and measure the energy (colour) and intensity of the photons. Using this technology, we are not only able to obtain attenuation contrast but also to image chemical (elemental) variations inside objects, potentially opening up a very wide range of applications from materials science to medical diagnostics.

  18. Energy-dispersive X-ray absorption spectroscopy at LNLS: investigation on strongly correlated metal oxides.

    PubMed

    Cezar, Júlio C; Souza-Neto, Narcizo M; Piamonteze, Cínthia; Tamura, Edilson; Garcia, Flávio; Carvalho, Edson J; Neueschwander, Régis T; Ramos, Aline Y; Tolentino, Hélio C N; Caneiro, Alberto; Massa, Nestor E; Martinez-Lope, Maria Jesus; Alonso, Jose Antonio; Itié, Jean Paul

    2010-01-01

    An energy-dispersive X-ray absorption spectroscopy beamline mainly dedicated to X-ray magnetic circular dichroism (XMCD) and material science under extreme conditions has been implemented in a bending-magnet port at the Brazilian Synchrotron Light Laboratory. Here the beamline technical characteristics are described, including the most important aspects of the mechanics, optical elements and detection set-up. The beamline performance is then illustrated through two case studies on strongly correlated transition metal oxides: an XMCD insight into the modifications of the magnetic properties of Cr-doped manganites and the structural deformation in nickel perovskites under high applied pressure. PMID:20029117

  19. High-pressure structural studies of dysprosium using angle-dispersive x-ray diffraction

    SciTech Connect

    Shen Yongrong; Kumar, Ravhi S.; Cornelius, Andrew L.; Nicol, Malcolm F. [Department of Physics and High Pressure Science and Engineering Center, University of Nevada Las Vegas, Las Vegas, Nevada 89154-4002 (United States)

    2007-02-01

    We present structural results under pressure for elemental dysprosium (Dy) up to 87 GPa using in situ angle-dispersive x-ray diffraction measurements with synchrotron x rays and a diamond-anvil cell. Dy exhibits the structural transition sequence, hP2{yields}hR9{yields}hP4{yields}distorted cF4, from Rietveld full-profile refinements. Clear evidence is documented for the high-pressure distorted cF4 phase observed above 45 GPa to be an orthorhombic oS8 (Cmmm) structure for Dy in the lanthanide phase diagram.

  20. Place of HgI/sub 2/ energy-dispersive x-ray detectors

    SciTech Connect

    Dabrowski, A.J.; Huth, G.C.; Iwanczyk, J.S.; Kusmiss, J.H.; Barton, J.S.; Szymczyk, J.M.; Schnepple, W.F.; Lynn, R.

    1982-01-01

    After a review of solid-state conduction counters, in general, and of the history of mercuric iodide, in particular, the theory of operation of solid-state energy-dispersive HgI/sub 2/ detectors is dicusssed. The main factors which limit energy resolution in solid-state compound detectors are considered, including statistical fluctuations in charge generation, the window effect, trapping, inhomogeneities in the detector material, and electronic noise. Potential applications of room-temperature HgI/sub 2/ x-ray detectors are listed, and general considerations are discussed for x-ray fluorescence analysis with HgI/sub 2/. Directions of current investigations are given. (LEW)

  1. High-energy processes in low-mass protostars - an X-ray to radio multi-wavelength perspective

    Microsoft Academic Search

    Jan Forbrich

    2007-01-01

    High-energy processes in protostars remain poorly understood. Only after the recently finished Chandra Orion Ultra-deep Project (COUP), statistically significant information on X-ray emission from Young Stellar Objects (YSOs) has been obtained. For an understanding of the mechanisms responsible for the X-ray emission, multi-wavelength correlations of flares, especially in the radio regime, are necessary and have become an active field of

  2. Tunable coherent radiation at soft X-ray wavelengths: Generation and interferometric applications

    SciTech Connect

    Rosfjord, Kristine Marie

    2004-07-01

    The availability of high power, spectrally and spatially coherent soft x-rays (SXR) would facilitate a wide variety of experiments as this energy region covers the primary resonances of many magnetic and biological materials. Specifically, there are the carbon and oxygen K-edges that are critical for biological imaging in the water window and the L-edges of iron, nickel, and cobalt for which imaging and scattering studies can be performed. A new coherent soft X-ray branchline at the Advanced Light Source has begun operation (beamline 12.0.2). Using the third harmonic from an 8 cm period undulator, this branch delivers coherent soft x-rays with photon energies ranging from 200eV to 1keV. This branchline is composed of two sub-branches one at 14X demagnification and the other 8X demagnification. The former is optimized for use at 500eV and the latter at 800eV. Here the expected power from the third harmonic of this undulator and the beamline design and characterization is presented. The characterization includes measurements on available photon flux as well as a series of double pinhole experiments to determine the coherence factor with respect to transverse distance. The first high quality Airy patterns at SXR wavelengths are created with this new beamline. The operation of this new beamline allows for interferometry to be performed in the SXR region. Here an interferometric experiment designed to directly determine the index of refraction of a material under test is performed. Measurements are first made in the EUV region using an established beamline (beamline12.0.1) to measure silicon, ruthenium and tantalum silicon nitride. This work is then extended to the SXR region using beamline 12.0.2 to test chromium and vanadium.

  3. Closing the gap to the diffraction limit: Near wavelength limited tabletop soft x-ray coherent diffractive imaging

    NASA Astrophysics Data System (ADS)

    Sandberg, Richard Lunt

    Light microscopy has greatly advanced our understanding of nature. The achievable resolution, however, is limited by optical wavelengths to around 200 nm. Using novel imaging and labeling technologies, resolutions beyond the diffraction limit can be achieved for specialized specimens using techniques such as near-field scanning optical microscopy, stimulated emission depletion microscopy and structured illumination microscopy [1--3]. This dissertation presents a versatile soft x-ray diffraction microscope with 50 nm resolution using tabletop coherent soft x-ray sources. This work represents the first high resolution demonstrations of coherent diffractive or lensless imaging using tabletop extreme ultraviolet and soft x-ray sources [4, 5]. This dissertation also presents the first use of field curvature correction in x-ray coherent imaging which allows high numerical aperture imaging and near-diffraction-limited resolution of 1.5lambda. The relevant theory behind high harmonic generation, the primary tabletop source used in this work, will be discussed as well as the theory behind coherent diffractive imaging. Additionally, the first demonstration of tabletop soft x-ray Fourier Transform holography is shown with important applications to shorter wavelength imaging with high harmonic generation with limited flux. A tabletop soft x-ray diffraction microscope should find broad applications in biology, nanoscience, and materials science due to its simple optical design, high resolution, large depth of field, 3D imaging capability, scalability to shorter wavelengths, and ultrafast temporal resolution.

  4. Development of an x-ray detector based on polymer- dispersed liquid crystal

    NASA Astrophysics Data System (ADS)

    Oh, K.; Hong, J.; Kim, G.; Park, S.; Min, B.; Yang, J.; Nam, S.

    2015-02-01

    The applications of active matrix flat-panel imagers (AMFPIs) in large-area x-ray imaging systems have increased over time but are still severely limited owing to its pixel resolution, complex fabrication processes, and high cost. As a solution, x-ray light valve (XLV) technology was introduced and expected to have a better resolution and contrast ratio than those of AMFPI, owing to its micrometer level of the LC cells and signal amplification by an external light source. The twisting angle of the LC cells was changed by charge carrier signals created in a photoconductor layer against x-rays, and the diagnostic images from XLV were acquired from the transmittance of the external light source. However, there was a possibility that the photoconductor layer may be crystallized or degenerated due to the application of high temperatures for sealing the LC layer during the fabrication process. To solve such problems, polymer-dispersed liquid crystals (PDLCs), which do not need high temperature for the sealing process of the LC layer, are used in this study instead of typical LC cells. A photoconductor and PDLC are combined to develop an x-ray detector. An external light source and optical sensor are used to investigate the light transmission of the PDLC . The PDLCs used in this paper do not need polarizers and are self-adhesive. Hence, the transmittance is very high in the transparent state, which allows for a linear x-ray response and sufficient dynamic range in digital radiography.

  5. High-resolution detectors for imaging and spectroscopy at ultraviolet and soft X-ray wavelengths

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.; Morgan, J. S.; Slater, D. C.

    1988-01-01

    The Multi-Anode Microchannel Arrays (MAMAs) are a family of pulse-counting imaging array detectors designed specifically for astrophysical investigations in space. The MAMAs have a number of unique performance characteristics which make them particularly suitable for imaging and spectroscopy at ultraviolet and soft X-ray wavelengths. First, they employ 'solar blind' photocathodes eliminating the 'red leak' problem associated with solid state arrays such as the CCDs. Second, they operate with zero readout noise, yielding photon-statistics limited signals. Third, they utilize a random readout technique and can determine both the location of a detected photon and also its arrival time to an accuracy of the order of 100 ns. This paper gives an overview of the construction, mode of operation, and performance characteristics of the MAMA detectors and describes the current status of the development program.

  6. X-ray beamsplitter

    Microsoft Academic Search

    Natale M. Ceglio; Daniel S. Stearns; Andrew M. Hawryluk; Barbee Jr. Troy W

    1989-01-01

    An x-ray beamsplitter which splits an x-ray beam into two coherent parts by reflecting and transmitting some fraction of an incident beam has applications for x-ray interferometry, x-ray holography, x-ray beam manipulation, and x-ray laser cavity output couplers. The beamsplitter is formed of a wavelength selective multilayer thin film supported by a very thin x-ray transparent membrane. The beamsplitter resonantly

  7. X-ray photo-emission and energy dispersive spectroscopy of HA coated titanium

    SciTech Connect

    Drummond, J.L.; Steinberg, A.D. [Univ. of Illinois, Chicago, IL (United States); Krauss, A.R. [Argonne National Lab., IL (United States)] [and others

    1997-08-01

    The purpose of this study was to determine the chemical composition changes of hydroxyapatite (HA) coated titanium using surface analysis (x-ray photo-emission) and bulk analysis (energy dispersive spectroscopy). The specimens examined were controls, 30 minutes and 3 hours aged specimens in distilled water or 0.2M sodium phosphate buffer (pH 7.2) at room temperature. Each x-ray photo-emission cycle consisted of 3 scans followed by argon sputtering for 10 minutes for a total of usually 20 cycles, corresponding to a sampling depth of {approximately} 1500 {angstrom}. The energy dispersive spectroscopy analysis was on a 110 by 90 {mu}m area for 500 sec. Scanning electron microscopy examination showed crystal formation (3P{sub 2}O{sub 5}*2CAO*?H{sub 2}O by energy dispersive spectroscopy analysis) on the HA coating for the specimens aged in sodium phosphate buffer. The x-ray photo-emission results indicated the oxidation effect of water on the titanium (as TiO{sub 2}) and the effect of the buffer to increase the surface concentration of phosphorous. No differences in the chemical composition were observed by energy dispersive spectroscopy analysis. The crystal growth was only observed for the sodium phosphate buffer specimens and only on the HA surface.

  8. A Soft X-ray Spectrometer using a Highly Dispersive Multilayer Grating

    SciTech Connect

    Warwick, Tony; Padmore, Howard; Voronov, Dmitriy; Yashchuk, Valeriy

    2010-01-31

    There is a need for higher resolution spectrometers as a tool for inelastic x-ray scattering. Currently, resolving power around R = 10,000 is advertised. Measured RIXS spectra are often limited by this instrumental resolution and higher resolution spectrometers using conventional gratings would be prohibitively large. We are engaged in a development program to build blazed multilayer grating structures for diffracting soft x-rays in high order. This leads to spectrometers with dispersion much higher than is possible using metal coated-gratings. The higher dispersion then provides higher resolution and the multilayer gratings are capable of operating away from grazing incidence as required. A spectrometer design is presented with a total length 3.8m and capable of 10{sup 5} resolving power.

  9. Dispersion and monochromatization of x-rays using a beryllium prism.

    PubMed

    Burza, M; Enquist, H; Jurgilaitis, A; Nygaard, J; Larsson, J

    2015-01-26

    We demonstrate experimentally and numerically that an x-ray prism made of beryllium can be used to disperse and monochromatize x-rays. A polished beryllium cuboid was employed as refractive and dispersive optics. The results of a proof-of-principle experiment and methods of performance optimization are presented. The spatial separation of undulator harmonics and their subsequent selection using a slit are described. A numerical study, assuming realistic beam and beamline parameters, suggests that undulator harmonics can be spatially separated in the range from 3 keV to beyond 20 keV, while maintaining throughput above 50%. Refractive optics is particularly suitable for low-repetition-rate sources such as free-electron lasers and other LINAC-based short-pulse sources. PMID:25835820

  10. Petrographic analysis using cathodoluminescence microscopy with simultaneous energy-dispersive X-ray spectroscopy

    Microsoft Academic Search

    W. Vortisch; D. Harding; J. Morgan

    2003-01-01

    Summary ¶Mineral grains unidentifiable by means of cathodoluminescence (CL) and\\/or polarizing microscopy (including non-luminescent or opaque minerals) can be readily identified with energy dispersive X-ray spectrometry, attached to the CL equipment. Chemical identification is possible of mineral grains (ten to a few tens of microns) that are even smaller than the electron beam area, by using index elements if the

  11. Dispersive x-ray synchrotron studies of Pt-C multilayers

    SciTech Connect

    Smither, R.K.; Rodricks, B.; Lamelas, F.; Medjahed, D.; Dos Passos, W.; Clarke, R.; Ziegler, E.; Fontaine, A.

    1989-02-01

    We demonstrate the simultaneous acquisition of high-resolution x-ray absorption spectra and scattering data, using a combination of energy-dispersive optics and a two-dimensional CCD detector. Results are presented on the optical constants of Pt and on the reflectivity of a platinum-carbon multilayer at the L/sub III/ absorption edge of Pt. 12 refs., 5 figs.

  12. Elemental analysis of mining wastes by energy dispersive X-ray fluorescence (EDXRF)

    Microsoft Academic Search

    O. Gonzalez-Fernandez; I. Queralt; M. L. Carvalho; G. Garcia

    2007-01-01

    An energy dispersive X-ray fluorescence (EDXRF) tri-axial geometry experimental spectrometer has been employed to determine the concentrations of 13 different elements (K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr and Pb) in mine wastes from different depths of two mine tailings from the Cartagena-La Union (Spain) mining district. The elements were determined and quantified using the

  13. The ChIcAGO Survey: Multi-wavelength Identification of Galactic Plane X-ray Sources

    NASA Astrophysics Data System (ADS)

    Anderson, Gemma; Gaensler, Bryan M.; Slane, Patrick O.; Kaplan, David L.A.; Posselt, Bettina

    2014-08-01

    I present the Chasing the Identification of ASCA Galactic Objects (ChIcAGO) survey, which is designed to identify the unknown X-ray sources discovered during the ASCA Galactic Plane Survey (AGPS). Little is known about most of the AGPS sources, especially those that emit primarily in hard X-rays (2-10 keV) within the F_ 10^-13 to 10^-11 erg cm^-2s^-1 X-ray flux range. In ChIcAGO, the subarcsecond localization capabilities of Chandra have been combined with a multi-wavelength follow-up program, with the ultimate goal of classifying the unidentified sources in the AGPS. Overall to date, 93 unidentified AGPS sources have been observed with Chandra as part of the ChIcAGO survey. A total of 253 X-ray point sources have been detected in these Chandra observations within 3' of the original ASCA positions, the majority of which have optical and infrared counterparts. Using these multi-wavelength follow-up results I have developed a new statistical diagnostic for identifying likely populations of X-ray emitting sources. These studies have revealed that the primary populations of Galactic plane X-ray sources that emit in the F_ 10^-13 to 10^-11 erg cm^-2s^-1 flux range are active stellar coronae, massive stars that are possibly in colliding-wind binaries, X-ray binaries, and magnetars. There is also another primary population that is still unidentified but, on the basis of its X-ray and infrared properties, likely comprise partly of Galactic sources and partly AGN.

  14. Energy dispersive X-ray diffraction in the diamond anvil, high-pressure apparatus - Comparison of synchrotron and conventional X-ray sources

    NASA Technical Reports Server (NTRS)

    Spain, I. L.; Black, D. R.

    1985-01-01

    The use of both conventional fixed-anode X-ray sources and synchrotron radiation to carry out energy-dispersive X-ray diffraction experiments at high pressure in a diamond anvil cell, is discussed. The photon flux at the sample and at the detector for the two cases are compared and the results are presented in graphs. It is shown that synchrotron radiation experiments can be performed with nearly two orders of magnitude increase in data rate if superior detectors and detector electronics are available.

  15. THE CORRELATION BETWEEN DISPERSION MEASURE AND X-RAY COLUMN DENSITY FROM RADIO PULSARS

    SciTech Connect

    He, C.; Ng, C.-Y.; Kaspi, V. M., E-mail: ncy@bohr.physics.hku.hk [Department of Physics, McGill University, Montreal, QC H3A 2T8 (Canada)

    2013-05-01

    Pulsars are remarkable objects that emit across the entire electromagnetic spectrum, providing a powerful probe of the interstellar medium. In this study, we investigate the relation between dispersion measure (DM) and X-ray absorption column density N{sub H} using 68 radio pulsars detected at X-ray energies with the Chandra X-Ray Observatory or XMM-Newton. We find a best-fit empirical linear relation of N{sub H} (10{sup 20} cm{sup -2})= 0.30{sup +0.13}{sub -0.09} DM (pc cm{sup -3}), which corresponds to an average ionization of 10{sup +4}{sub -3}%, confirming the ratio of one free electron per 10 neutral hydrogen atoms commonly assumed in the literature. We also compare different N{sub H} estimates and note that some N{sub H} values obtained from X-ray observations are higher than the total Galactic H I column density along the same line of sight, while the optical extinction generally gives the best N{sub H} predictions.

  16. High Performance Non-Dispersive X-Ray Spectrometers for Charge Exchange Measurements

    NASA Technical Reports Server (NTRS)

    Porter Frederick; Adams, J.; Beiersdorfer, P.; Brown, G. V.; Karkatoua, D.; Kelley, R. L.; Kilbourne, C. A.; Lautenagger, M.

    2010-01-01

    Currently, the only measurements of cosmological charge exchange have been made using low resolution, non-dispersive spectrometers like the PSPC on ROSAT and the CCD instruments on Chandra and XMM/Newton. However, upcoming cryogenic spectrometers on Astro-H and IXO will add vast new capabilities to investigate charge exchange in local objects such as comets and planetary atmospheres. They may also allow us to observe charge exchange in extra-solar objects such as galactic supernova remnants. With low spectral resolution instruments such as CCDs, x-ray emission due to charge exchange recombination really only provides information on the acceptor species, such as the solar wind. With the new breed of x-ray calorimeter instruments, emission from charge exchange becomes highly diagnostic allowing one to uniquely determine the acceptor species, ionization state, donor species and ionization state, and the relative velocity of the interaction. We will describe x-ray calorimeter instrumentation and its potential for charge exchange measurements in the near term. We will also touch on the instrumentation behind a decade of high resolution measurements of charge exchange using an x-ray calorimeter at the Lawrence Livermore National Laboratory.

  17. LOCALIZING INTEGRAL SOURCES WITH CHANDRA: X-RAY AND MULTI-WAVELENGTH IDENTIFICATIONS AND ENERGY SPECTRA

    SciTech Connect

    Tomsick, John A.; Bodaghee, Arash [Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450 (United States); Chaty, Sylvain; Rodriguez, Jerome [AIM (UMR-E 9005 CEA/DSM-CNRS-Universite Paris Diderot) Irfu/Service d'Astrophysique, Centre de Saclay, FR-91191 Gif-sur-Yvette Cedex (France); Rahoui, Farid [Astronomy Department, Harvard University, 60 Garden Street, Cambridge, MA 02138 (United States); Halpern, Jules [Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, New York, NY 10027-6601 (United States); Kalemci, Emrah [Faculty of Engineering and Natural Sciences, Sabanc Latin-Small-Letter-Dotless-I University, Orhanl Latin-Small-Letter-Dotless-I -Tuzla, Istanbul 34956 (Turkey); Oezbey Arabaci, Mehtap, E-mail: jtomsick@ssl.berkeley.edu [Physics Department, Middle East Technical University, Ankara 06531 (Turkey)

    2012-08-01

    We report on Chandra observations of 18 hard X-ray (>20 keV) sources discovered with the INTEGRAL satellite near the Galactic plane. For 14 of the INTEGRAL sources, we have uncovered one or two potential Chandra counterparts per source. These provide soft X-ray (0.3-10 keV) spectra and subarcsecond localizations, which we use to identify counterparts at other wavelengths, providing information about the nature of each source. Despite the fact that all of the sources are within 5 Degree-Sign of the plane, four of the IGR sources are active galactic nuclei (AGNs; IGR J01545+6437, IGR J15391-5307, IGR J15415-5029, and IGR J21565+5948) and four others are likely AGNs (IGR J03103+5706, IGR J09189-4418, IGR J16413-4046, and IGR J16560-4958) based on each of them having a strong IR excess and/or extended optical or near-IR emission. We compare the X-ray and near-IR fluxes of this group of sources to those of AGNs selected by their 2-10 keV emission in previous studies and find that these IGR AGNs are in the range of typical values. There is evidence in favor of four of the sources being Galactic (IGR J12489-6243, IGR J15293-5609, IGR J16173-5023, and IGR J16206-5253), but only IGR J15293-5609 is confirmed as a Galactic source as it has a unique Chandra counterpart and a parallax measurement from previous optical observations that puts its distance at 1.56 {+-} 0.12 kpc. The 0.3-10 keV luminosity for this source is (1.4{sup +1.0}{sub -0.4}) Multiplication-Sign 10{sup 32} erg s{sup -1}, and its optical/IR spectral energy distribution is well described by a blackbody with a temperature of 4200-7000 K and a radius of 12.0-16.4 R{sub Sun }. These values suggest that IGR J15293-5609 is a symbiotic binary with an early K-type giant and a white dwarf accretor. We also obtained likely Chandra identifications for IGR J13402-6428 and IGR J15368-5102, but follow-up observations are required to constrain their source types.

  18. CUBIC - A non-dispersive Diffuse X-ray Background spectrometer. [Cosmic Unresolved X-ray Background Instrument

    NASA Technical Reports Server (NTRS)

    Burrows, David N.; Skinner, Mark A.; Antunes, Alexander J. D.; Catalano, Mark A.; Cocklin, Eric J.; Engel, Leland G.; Entingh, Timothy J.; Garmire, Gordon P.; Green, Roland; Kelly, Douglas A.

    1992-01-01

    The Cosmic Unresolved X-ray Background Instrument using CCDs (CUBIC) is designed to obtain spectral observations of the Diffuse X-ray Background (DXRB) with moderate spectral resolution over the energy range 0.2-10 keV, using mechanically-collimated CCDs. At this time, it is the only planned satellite payload devoted to the study of the spectrum of the DXRB. Over the anticipated 3 year lifetime of the satellite, CUBIC will be able to study up to 50 percent of the sky with 5 x 5 deg spatial resolution for the subkilovolt Galactic diffuse background, and with 10 x 10 deg spatial resolution for the extragalactic diffuse background above 2 keV. CUBIC will obtain high quality nondispersive spectra of soft X-ray emission from the interstellar medium, supernova remnants, and some bright sources, and will make a sensitive seach for line emission or other features in the extragalactic cosmic X-ray background from 2-10 keV.

  19. At-wavelength and optical metrology of bendable x-ray optics for nanofocusing at the ALS

    SciTech Connect

    Yashchuk, Valeriy V.

    2009-06-11

    We report on a new research and development program at the Advanced Light Source, Lawrence Berkeley National Lab directed to establish both at-wavelength and conventional optical metrology techniques suitable to characterize the surface profile of super-high-quality x-ray optics with sub-microradian precision.

  20. Photon Counting Energy Dispersive Detector Arrays for X-ray Imaging

    PubMed Central

    Iwanczyk, Jan S.; Nygård, Einar; Meirav, Oded; Arenson, Jerry; Barber, William C.; Hartsough, Neal E.; Malakhov, Nail; Wessel, Jan C.

    2009-01-01

    The development of an innovative detector technology for photon-counting in X-ray imaging is reported. This new generation of detectors, based on pixellated cadmium telluride (CdTe) and cadmium zinc telluride (CZT) detector arrays electrically connected to application specific integrated circuits (ASICs) for readout, will produce fast and highly efficient photon-counting and energy-dispersive X-ray imaging. There are a number of applications that can greatly benefit from these novel imagers including mammography, planar radiography, and computed tomography (CT). Systems based on this new detector technology can provide compositional analysis of tissue through spectroscopic X-ray imaging, significantly improve overall image quality, and may significantly reduce X-ray dose to the patient. A very high X-ray flux is utilized in many of these applications. For example, CT scanners can produce ~100 Mphotons/mm2/s in the unattenuated beam. High flux is required in order to collect sufficient photon statistics in the measurement of the transmitted flux (attenuated beam) during the very short time frame of a CT scan. This high count rate combined with a need for high detection efficiency requires the development of detector structures that can provide a response signal much faster than the transit time of carriers over the whole detector thickness. We have developed CdTe and CZT detector array structures which are 3 mm thick with 16×16 pixels and a 1 mm pixel pitch. These structures, in the two different implementations presented here, utilize either a small pixel effect or a drift phenomenon. An energy resolution of 4.75% at 122 keV has been obtained with a 30 ns peaking time using discrete electronics and a 57Co source. An output rate of 6×106 counts per second per individual pixel has been obtained with our ASIC readout electronics and a clinical CT X-ray tube. Additionally, the first clinical CT images, taken with several of our prototype photon-counting and energy-dispersive detector modules, are shown. PMID:19920884

  1. Characterization of "oil on copper" paintings by energy dispersive X-ray fluorescence spectrometry.

    PubMed

    Pitarch, A; Ramón, A; Álvarez-Pérez, A; Queralt, I

    2012-02-01

    Energy dispersive X-ray fluorescence is a common analytical tool for layer thickness measurements in quality control processes in the coating industry, but there are scarce microanalytical applications in order to ascertain semi-quantitative or quantitative information of painted layers. "Oil on copper" painting becomes a suitable material to be analysed by means of X-ray fluorescence spectrometry, due to the metallic nature of substrate and the possibility of applying layered models as used in coating industry. The aim of this work is to study the suitability of a quantitative energy dispersive X-ray fluorescence methodology for the assessment of the areal distribution of pigments and the characterization of painting methods on such kind of pictorial artworks. The method was calibrated using standard reference materials: dried droplets of monoelemental standard solutions laid on a metallic plate of copper. As an example of application, we estimated pigment mass distribution of two "oil on copper" paintings from the sixteenth and eighteenth centuries. Pictorial layers have been complementarily analysed by X-ray diffraction. Apart of the supporting media made of copper or brass, we could identify two different superimposed layers: (a) a preparation layer mainly composed by white lead and (b) the pictorial layer of variable composition depending on the pigments used by the artist on small areas of the painting surface. The areal mass distribution of the different elements identified in the painting pigments (Ca, Cr, Mn, Fe, Zn, Cd, Hg and Pb) have been determined by elemental mapping of some parts of the artworks. PMID:21904800

  2. At-wavelength characterization of refractive x-ray lenses using a two-dimensional grating interferometer

    NASA Astrophysics Data System (ADS)

    Rutishauser, Simon; Zanette, Irene; Weitkamp, Timm; Donath, Tilman; David, Christian

    2011-11-01

    We report on the application of a two-dimensional hard x-ray grating interferometer to x-ray optics metrology. The interferometer is sensitive to refraction angles in two perpendicular directions with a precision of 10 nrad. It is used to observe the wavefront changes induced by a single parabolic beryllium focusing lens of large radius of curvature. The lens shape is reconstructed and its residual aberrations are analyzed. Its profile differs from an ideal parabolic shape by less than 2 ?m or ?/50 at ? = 0.54 Å wavelength.

  3. MULTI-WAVELENGTH OBSERVATIONS OF SOLAR FLARES WITH A CONSTRAINED PEAK X-RAY FLUX

    SciTech Connect

    Bowen, Trevor A.; Testa, Paola; Reeves, Katharine K., E-mail: tbowen@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 58, Cambridge, MA 02138 (United States)

    2013-06-20

    We present an analysis of soft X-ray (SXR) and extreme-ultraviolet (EUV) observations of solar flares with an approximate C8 Geostationary Operational Environmental Satellite (GOES) class. Our constraint on peak GOES SXR flux allows for the investigation of correlations between various flare parameters. We show that the duration of the decay phase of a flare is proportional to the duration of its rise phase. Additionally, we show significant correlations between the radiation emitted in the flare rise and decay phases. These results suggest that the total radiated energy of a given flare is proportional to the energy radiated during the rise phase alone. This partitioning of radiated energy between the rise and decay phases is observed in both SXR and EUV wavelengths. Though observations from the EUV Variability Experiment show significant variation in the behavior of individual EUV spectral lines during different C8 events, this work suggests that broadband EUV emission is well constrained. Furthermore, GOES and Atmospheric Imaging Assembly data allow us to determine several thermal parameters (e.g., temperature, volume, density, and emission measure) for the flares within our sample. Analysis of these parameters demonstrate that, within this constrained GOES class, the longer duration solar flares are cooler events with larger volumes capable of emitting vast amounts of radiation. The shortest C8 flares are typically the hottest events, smaller in physical size, and have lower associated total energies. These relationships are directly comparable with several scaling laws and flare loop models.

  4. WAVELENGTH MEASUREMENTS OF K TRANSITIONS OF OXYGEN, NEON, AND MAGNESIUM WITH X-RAY ABSORPTION LINES

    SciTech Connect

    Liao Jinyuan; Zhang Shuangnan [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Yao Yangsen, E-mail: zhangsn@ihep.ac.cn [Eureka Scientific, 2452 Delmer Street Suite 100, Oakland, CA 94602 (United States)

    2013-09-10

    Accurate atomic transition data are important in many astronomical research areas, especially for studies of line spectroscopy. Whereas transition data of He-like and H-like ions (i.e., ions in high-charge states) have been accurately calculated, the corresponding data of K transitions of neutral or low-ionized metal elements are still very uncertain. Spectroscopy of absorption lines produced in the interstellar medium (ISM) has been proven to be an effective way to measure the central wavelengths of these atomic transitions. In this work, we analyze 36 Chandra High Energy Transmission Grating observations to search for and measure the ISM absorption lines along sight lines to 11 low-mass X-ray binaries. We correct the Galactic rotation velocity to the rest frame for every observation and then use two different methods to merge all the corrected spectra to a co-added spectrum. However, the co-added spectra obtained by this method exhibit biases, toward to either observations with high counts or lines with high signal-to-noise ratios. We do a Bayesian analysis of several significantly detected lines to obtain the systematic uncertainty and the bias correction for other lines. Compared to previous studies, our results improve the wavelength accuracy by a factor of two to five and significantly reduce the systematic uncertainties and biases. Several weak transitions (e.g., 1s-2p of Mg IV and Mg V; 1s-3p of Mg III and Mg V) are also detected for the first time, albeit with low significance; future observations with improved accuracy are required to confirm these detections.

  5. Wavelength Measurements of K Transitions of Oxygen, Neon, and Magnesium with X-Ray Absorption Lines

    NASA Astrophysics Data System (ADS)

    Liao, Jin-Yuan; Zhang, Shuang-Nan; Yao, Yangsen

    2013-09-01

    Accurate atomic transition data are important in many astronomical research areas, especially for studies of line spectroscopy. Whereas transition data of He-like and H-like ions (i.e., ions in high-charge states) have been accurately calculated, the corresponding data of K transitions of neutral or low-ionized metal elements are still very uncertain. Spectroscopy of absorption lines produced in the interstellar medium (ISM) has been proven to be an effective way to measure the central wavelengths of these atomic transitions. In this work, we analyze 36 Chandra High Energy Transmission Grating observations to search for and measure the ISM absorption lines along sight lines to 11 low-mass X-ray binaries. We correct the Galactic rotation velocity to the rest frame for every observation and then use two different methods to merge all the corrected spectra to a co-added spectrum. However, the co-added spectra obtained by this method exhibit biases, toward to either observations with high counts or lines with high signal-to-noise ratios. We do a Bayesian analysis of several significantly detected lines to obtain the systematic uncertainty and the bias correction for other lines. Compared to previous studies, our results improve the wavelength accuracy by a factor of two to five and significantly reduce the systematic uncertainties and biases. Several weak transitions (e.g., 1s-2p of Mg IV and Mg V; 1s-3p of Mg III and Mg V) are also detected for the first time, albeit with low significance; future observations with improved accuracy are required to confirm these detections.

  6. Identification of inorganic dust particles in bronchoalveolar lavage macrophages by energy dispersive x-ray microanalysis.

    PubMed

    Johnson, N F; Haslam, P L; Dewar, A; Newman-Taylor, A J; Turner-Warwick, M

    1986-01-01

    This study shows that energy dispersive x-ray microprobe analysis to identify and quantify intracellular particles in macrophages obtained by the minimally invasive method of bronchoalveolar lavage (BAL) can detect inorganic dust exposures of many different kinds. Bronchoalveolar lavage macrophages from 22 patients have been examined. Twelve patients had occupational exposure to asbestos, talc, silica, hard metal or printing ink, while 10 had no known history of dust exposure. X-ray microprobe analysis identified particles which related to the known exposures, superimposed on a background of other particles related to smoking (kaolinite and mica) or to the general environment (silicon, titanium, and iron). The particle identification provided useful objective confirmation of the known exposures, except for silica, which could not be distinguished from the general background levels. X-ray microanalysis using BAL macrophages can be helpful for clarification of mixed dust exposures, to identify particles when light microscopy indicates retained dust in patients with no known history of exposure, and to monitor retained particles after removal from exposure. PMID:3740951

  7. X-ray Photon Correlation Spectroscopy: A New Probe of Short Wavelength Dynamics

    NASA Astrophysics Data System (ADS)

    Dierker, S. B.

    1996-03-01

    The new field of x-ray photon correlation spectroscopy (XPCS) offers an unprecedented opportunity to extend the range of length scales over which a material's low frequency dynamics can be studied down to interatomic spacings. The critical development which has now made XPCS a feasible technique is the high brightness of insertion devices at second and third generation synchrotron sources. In this talk, I will describe the principles of the XPCS technique and how it is practiced, as well as its potential use for a variety of important problems in the low frequency dynamics of condensed matter systems, such as complex fluids, glasses, surfaces, and metallic alloys. Illustrations will be drawn from our(Research done in collaboration with R. Pindak, R. M. Fleming, I. K. Robinson, L. Berman, G. Grubel, and D. L. Abernathy. S.B.D. supported by NSF DMR92-17956. I.K.R. supported by NSF MDR 93-15691. The NSLS is supported by DOE DE-AC02-76CH00016.) results(S. B. Dierker, R. Pindak, R. M. Fleming, I. K. Robinson, L. Berman, Phys. Rev. Lett. 75), 449 (1995). on using XPCS to study the Brownian motion of a gold colloid. We made small angle x-ray scattering measurements of the static structure factor of an optically opaque gold colloid dispersed in the viscous liquid glycerol. We discovered a novel effect due to photoemission induced charging of the gold colloid which could be suppressed by the addition of salt. We determined the dynamic correlation functions for the Brownian motion of the colloid particles at wavevectors between 10-3 <= q <= 10-2 Åwhich extends well beyond the range of visible light scattering. The resulting diffusion coefficient is very q dependent, scaling approximately as D(q) = D_o/S(q). The results of recent progress in using the Prototype Small Gap Undulator (PSGU) at beam line X13 at the NSLS will also be described. We(Research done in collaboration with L. Berman, Z. Yin, and E. Dufresne.) have achieved a coherent flux of > 10^10 photons/second in a `pink' beam at 3 keV by using a mirror to filter out the harmonics. This should be an excellent source for small angle XPCS measurements. The results of initial experiments conducted with the PSGU will be presented. The experiments were conducted at the wiggler beam line X25 and the PSGU beamline X13 at the NSLS and at the undulator beamline 9/ID10 (Troika) at the ESRF.

  8. Determination of carrier yields for neutron activation analysis using energy dispersive X-ray spectrometry

    USGS Publications Warehouse

    Johnson, R.G.; Wandless, G.A.

    1984-01-01

    A new method is described for determining carrier yield in the radiochemical neutron activation analysis of rare-earth elements in silicate rocks by group separation. The method involves the determination of the rare-earth elements present in the carrier by means of energy-dispersive X-ray fluorescence analysis, eliminating the need to re-irradiate samples in a nuclear reactor after the gamma ray analysis is complete. Results from the analysis of USGS standards AGV-1 and BCR-1 compare favorably with those obtained using the conventional method. ?? 1984 Akade??miai Kiado??.

  9. Quantitative analysis of annealed scanning probe tips using energy dispersive x-ray spectroscopy

    SciTech Connect

    Cobley, R. J.; Brown, R. A.; Barnett, C. J.; Maffeis, T. G. G.; Penny, M. W. [Multidisciplinary Nanotechnology Centre, College of Engineering, Swansea University, Singleton Park, Swansea SA2 8PP (United Kingdom)] [Multidisciplinary Nanotechnology Centre, College of Engineering, Swansea University, Singleton Park, Swansea SA2 8PP (United Kingdom)

    2013-01-14

    A quantitative method to measure the reduction in oxide species on the surface of electrochemically etched tungsten tips during direct current annealing is developed using energy dispersive x-ray spectroscopy. Oxide species are found to decrease with annealing current, with the trend repeatable over many tips and along the length of the tip apex. A linear resistivity approximation finds significant oxide sublimation occurs at 1714 K, but surface melting and tip broadening at 2215 K. This method can be applied to calibrate any similar annealing stage, and to identify the tradeoff regime between required morphological and chemical properties.

  10. Application of energy dispersive X-ray fluorescence spectrometry (EDX) in a case of methomyl ingestion.

    PubMed

    Kinoshita, Hiroshi; Tanaka, Naoko; Jamal, Mostofa; Kumihashi, Mitsuru; Okuzono, Ryota; Tsutsui, Kunihiko; Ameno, Kiyoshi

    2013-04-10

    We applied energy dispersive X-ray fluorescence spectrometry (EDX) in a case of poisoning by methomyl, a carbamate pesticide. Quantitative GC/MS analysis showed that the concentration of methomyl-oxime in the femoral blood was 4.0 ?g/ml. The elemental analysis by EDX identified the high peak of silicon and sulfur in the stomach contents. We concluded that the cause of his death was methomyl poisoning. This indicates that screening of stomach contents by EDX provides useful information for the forensic diagnosis. PMID:22999231

  11. Characterization of Japanese color sticks by energy dispersive X-ray fluorescence, X-ray diffraction and Fourier transform infrared analysis

    NASA Astrophysics Data System (ADS)

    Manso, M.; Valadas, S.; Pessanha, S.; Guilherme, A.; Queralt, I.; Candeias, A. E.; Carvalho, M. L.

    2010-04-01

    This work comprises the use of energy dispersive X-ray fluorescence (EDXRF), X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) techniques for the study of the composition of twentieth century traditional Japanese color sticks. By using the combination of analytical techniques it was possible to obtain information on inorganic and organic pigments, binders and fillers present in the sticks. The colorant materials identified in the sticks were zinc and titanium white, chrome yellow, yellow and red ochre, vermillion, alizarin, indigo, Prussian and synthetic ultramarine blue. The results also showed that calcite and barite were used as inorganic mineral fillers while Arabic gum was the medium used. EDXRF offered great potential for such investigations since it allowed the identification of the elements present in the sample preserving its integrity. However, this information alone was not enough to clearly identify some of the materials in study and therefore it was necessary to use XRD and FTIR techniques.

  12. Practical applications of energy dispersive X-ray microanalysis in diagnostic oral pathology

    SciTech Connect

    Daley, T.D.; Gibson, D. (Univ. of Western Ontario, London (Canada))

    1990-03-01

    Energy dispersive X-ray microanalysis is a powerful tool that can reveal the presence and relative quantities of elements in minute particles in biologic materials. Although this technique has been used in some aspects of dental research, it has rarely been applied to diagnostic oral pathology. The purpose of this paper is to inform practicing dentists and oral specialists about the diagnostic potential of this procedure by presenting three case reports. The first case involved the identification of flakes of a metallic material claimed by a 14-year-old girl to appear periodically between her mandibular molars. In the second case, a periodontist was spared a lawsuit when a freely mobile mass in the antrum of his patient was found to be a calcium-phosphorus compound not related to the periodontal packing that had been used. The third case involved the differential diagnosis of amalgam tattoo and graphite tattoo in a pigmented lesion of the hard palate mucosa. The results of the analyses were significant and indicate a role for this technique in the assessment of selected cases. Potential for wider use of energy dispersive X-ray microanalysis in diagnostic oral pathology exists as research progresses.

  13. MULTI-WAVELENGTH STUDY OF THE Be/X-RAY BINARY MXB 0656-072

    SciTech Connect

    Yan Jingzhi; Li Hui; Liu Qingzhong [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Zurita Heras, Juan Antonio; Chaty, Sylvain, E-mail: jzyan@pmo.ac.cn, E-mail: hli@pmo.ac.cn, E-mail: qzliu@pmo.ac.cn, E-mail: juan-antonio.zurita-heras@cea.fr, E-mail: sylvain.chaty@cea.fr [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, IRFU/Service d'Astrophysique, FR-91191 Gif-sur-Yvette (France)

    2012-07-01

    We present and analyze the optical photometric and spectroscopic data of the Be/X-ray binary MXB 0656-072 from 2006 to 2009. A 101.2 day orbital period is found, for the first time, from the present public X-ray data (Swift/BAT and RXTE/ASM). The anti-correlation between the H{alpha} emission and the UBV brightness of MXB 0656-072 during our 2007 observations indicates that a mass ejection event took place in the system. After the mass ejection, a low-density region might develop around the Oe star. With the outward motion of the circumstellar disk, the outer part of the disk interacted with the neutron star around its periastron passage and a series of X-ray outbursts were triggered between MJD 54350 and MJD 54850. The Proportional Counter Array-HEXTE spectra during the 2007-2008 X-ray outbursts could be well fitted by a cutoff power law with low-energy absorption, together with an iron line around 6.4 keV, and a broad cyclotron resonance feature around 30 keV. The same variability of the soft and hard X-ray colors in 2.3-21 keV indicated that there were no overall changes in the spectral shape during the X-ray outbursts, which might only be connected with the changes of the mass accretion rate onto the neutron star.

  14. Inelastic x-ray scattering study of plasmon dispersions in solid and liquid Rb

    NASA Astrophysics Data System (ADS)

    Kimura, K.; Matsuda, K.; Hiraoka, N.; Fukumaru, T.; Kajihara, Y.; Inui, M.; Yao, M.

    2014-01-01

    The plasmon dispersion relations in solid and liquid Rb were determined by inelastic x-ray scattering techniques. In liquid Rb, the plasmon energy increases with the momentum transfer q, whereas in solid Rb, the dispersion curve exhibits a cusplike shape. We also found that the plasmon linewidth in liquid Rb is narrower than that in solid Rb near q =0. These features suggest that the conduction electrons in liquid Rb are more suitably described by the electron gas model than in solid Rb, since the electron gas model predicts a smooth increase in the plasmon energy with q and the infinite lifetime at q =0. The origins of the observed variations in the plasmon energy and the linewidth upon melting are investigated with the aid of theoretical calculations.

  15. X-ray Emission Collected in a Novel Energy Dispersive Approach

    NASA Astrophysics Data System (ADS)

    Finkelstein, K. D.; Agyeman-Budu, D.; Lyndaker, A.; Pollock, C.; Krawczyk, T.

    2014-03-01

    Novel methods & materials have been used to produce dynamically bent Bragg diffraction analyzer crystals in a modified von Hamos geometry.They are used to collect a wide energy range X-ray emission spectrum over a large solid angle with electron volt resolution. Crystals fabricated from silicon-on-insulator wafers by photolithography and deep reactive ion etching can bend to 10 cm radius without increased lattice strain. The design permits adjustment of energy dispersion for individual analyzers in an array. A multilayer mono, mono-capillary focusing, and multi-crystal spectrometer together collect signals at a bend magnet beamline comparable to those from an undulator. Preliminary measurements validate this new energy dispersive spectrometer.

  16. A Multi-wavelength study of the Pulsar PSR B1929+10 and its X-ray trail

    E-print Network

    Werner Becker; Michael Kramer; Axel Jessner; Ronald E. Taam; Jian J. Jia; Kwong S. Cheng; Roberto Mignani; Alberto Pellizzoni; Andrea de Luca; Agnieszka Slowikowska; Patrizia Caraveo

    2006-03-16

    We report on the emission properties of PSR B1929+10 and its putative X-ray trail from a multi-wavelength study performed with XMM-Newton, the ESO NTT, the HST, the Effelsberg 100m Radio Telescope and the Jodrell Bank Radio Observatory. The XMM-Newton observations confirm the existence of the diffuse emission with a trail morphology lying in a direction opposite to the transverse motion of the pulsar. The trail has a length of ~15 arcmin. Its spectrum is non-thermal and produced by electron-synchrotron emission in the shock between the pulsar wind and the surrounding medium. Assuming that the electron lifetime against synchrotron cooling is comparable to the source transit time over the X-ray trail length, the magnetic field strength in the trail emitting region is inferred to be ~5 uG. Inspecting data from the Effelsberg 11cm radio continuum survey of the Galactic plane we discovered an elongated feature apparently coincident with the X-ray trail. The emission properties observed from PSR 1929+10 are found to finally challenge the picture of the emission properties of old non-recycled rotation powered pulsars. Both, the temporal and spectral X-ray emission properties of PSR 1929+10 are in excellent agreement with a non-thermal and, thus, magnetospheric radiation dominated emission scenario. A flux contribution from the thermal emission of heated polar caps of ~7% is inferred from a best fitting composite Planckian and power law spectral model. The X-ray pulse profile is found to be markedly different from the broad sinusoidal pulse profile seen in the low statistic ROSAT data. Simulations in the framework of an outer-gap emission model are able to reproduce the observed X-ray pulse profile and its phase relation relative to the radio pulse.

  17. High-average-power, 100-Hz-repetition-rate, tabletop soft-x-ray lasers at sub-15-nm wavelengths

    SciTech Connect

    Reagan, Brendon [Colorado State University, Fort Collins] [Colorado State University, Fort Collins; Berrill, Mark A [ORNL] [ORNL; Wernsing, Keith [Colorado State University, Fort Collins] [Colorado State University, Fort Collins; Baumgarten, Cory [Colorado State University, Fort Collins] [Colorado State University, Fort Collins; Woolston, Mark [Colorado State University, Fort Collins] [Colorado State University, Fort Collins; Rocca, Jorge [Colorado State University, Fort Collins] [Colorado State University, Fort Collins

    2014-01-01

    Efficient excitation of dense plasma columns at 100-Hz repetition rate using a tailored pump pulse profile produced a tabletop soft-x-ray laser average power of 0.1 mW at = 13.9 nm and 20 W at = 11.9 nm from transitions of Ni-like Ag and Ni-like Sn, respectively. Lasing on several other transitions with wavelengths between 10.9 and 14.7 nm was also obtained using 0.9-J pump pulses of 5-ps duration from a compact diode-pumped chirped pulse amplification Yb:YAG laser. Hydrodynamic and atomic plasma simulations show that the pump pulse profile, consisting of a nanosecond ramp followed by two peaks of picosecond duration, creates a plasma with an increased density of Ni-like ions at the time of peak temperature that results in a larger gain coefficient over a temporally and spatially enlarged space leading to a threefold increase in the soft-x-ray laser output pulse energy. The high average power of these compact soft-x-ray lasers will enable applications requiring high photon flux. These results open the path to milliwatt-average-power tabletop soft-x-ray lasers.

  18. Micro energy dispersive X-ray fluorescence analysis of polychrome lead-glazed Portuguese faiences

    NASA Astrophysics Data System (ADS)

    Guilherme, A.; Pessanha, S.; Carvalho, M. L.; dos Santos, J. M. F.; Coroado, J.

    2010-04-01

    Several glazed ceramic pieces, originally produced in Coimbra (Portugal), were submitted to elemental analysis, having as premise the pigment manufacture production recognition. Although having been produced in Coimbra, their location changed as time passed due to historical reasons. A recent exhibition in Coimbra brought together a great number of these pieces and in situ micro Energy Dispersive X-ray Fluorescence (µ-EDXRF) analyses were performed in order to achieve some chemical and physical data on the manufacture of faiences in Coimbra. A non-commercial µ-EDXRF equipment for in situ analysis was employed in this work, carrying some important improvements when compared to the conventional ones, namely, analyzing spot sizes of about 100 µm diameter. The combination of a capillary X-ray lens with a new generation of low power microfocus X-ray tube and a drift chamber detector enabled a portable unit for micro-XRF with a few tens of µm lateral resolution. The advantages in using a portable system emphasized with polycapillary optics enabled to distinguish proximal different pigmented areas, as well as the glaze itself. These first scientific results on the pigment analysis of the collection of faiences seem to point to a unique production center with own techniques and raw materials. This conclusion arose with identification of the blue pigments having in its constitution Mn, Fe Co and As and the yellows as a result of the combination between Pb and Sb. A statistical treatment was used to reveal groups of similarities on the pigments elemental profile.

  19. THE CHANDRA MULTI-WAVELENGTH PROJECT: OPTICAL SPECTROSCOPY AND THE BROADBAND SPECTRAL ENERGY DISTRIBUTIONS OF X-RAY-SELECTED AGNs

    SciTech Connect

    Trichas, Markos; Green, Paul J.; Aldcroft, Tom; Kim, Dong-Woo; Mossman, Amy [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Silverman, John D. [Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo, Kashiwanoha 5-1-5, Kashiwa-shi, Chiba 277-8568 (Japan); Barkhouse, Wayne [Department of Physics and Astrophysics, University of North Dakota, Grand Forks, ND 58202 (United States); Cameron, Robert A. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Constantin, Anca [Department of Physics and Astronomy, James Madison University, PHCH, Harrisonburg, VA 22807 (United States); Ellison, Sara L. [Department of Physics and Astronomy, University of Victoria, Victoria, BC V8P 1A1 (Canada); Foltz, Craig [Division of Astronomical Sciences, National Science Foundation, 4201 Wilson Blvd., Arlington, VA 22230 (United States); Haggard, Daryl [Center for Interdisciplinary Exploration and Research in Astrophysics, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States); Jannuzi, Buell T. [NOAO, Kitt Peak National Observatory, Tucson, AZ 85726 (United States); Marshall, Herman L. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 (United States); Perez, Laura M. [Department of Astronomy, California Institute of Technology, 1200 East California Blvd, Pasadena, CA 91125 (United States); Romero-Colmenero, Encarni [South African Astronomical Observatory, P.O. Box 9, Observatory, 7935 (South Africa); Ruiz, Angel [Osservatorio Astronomico di Brera-INAF, Milan (Italy); Smith, Malcolm G., E-mail: mtrichas@cfa.harvard.edu [Cerro Tololo Interamerican Observatory, La Serena (Chile); and others

    2012-06-01

    From optical spectroscopy of X-ray sources observed as part of the Chandra Multi-wavelength Project (ChaMP), we present redshifts and classifications for a total of 1569 Chandra sources from our targeted spectroscopic follow-up using the FLWO/1.5 m, SAAO/1.9 m, WIYN 3.5 m, CTIO/4 m, KPNO/4 m, Magellan/6.5 m, MMT/6.5 m, and Gemini/8 m telescopes, and from archival Sloan Digital Sky Survey (SDSS) spectroscopy. We classify the optical counterparts as 50% broad-line active galactic nuclei (AGNs), 16% emission line galaxies, 14% absorption line galaxies, and 20% stars. We detect QSOs out to z {approx} 5.5 and galaxies out to z {approx} 3. We have compiled extensive photometry, including X-ray (ChaMP), ultraviolet (GALEX), optical (SDSS and ChaMP-NOAO/MOSAIC follow-up), near-infrared (UKIDSS, Two Micron All Sky Survey, and ChaMP-CTIO/ISPI follow-up), mid-infrared (WISE), and radio (FIRST and NVSS) bands. Together with our spectroscopic information, this enables us to derive detailed spectral energy distributions (SEDs) for our extragalactic sources. We fit a variety of template SEDs to determine bolometric luminosities, and to constrain AGNs and starburst components where both are present. While {approx}58% of X-ray Seyferts (10{sup 42} erg s{sup -1} < L{sub 2-10keV} <10{sup 44} erg s{sup -1}) require a starburst event (>5% starburst contribution to bolometric luminosity) to fit observed photometry only 26% of the X-ray QSO (L{sub 2-10keV} >10{sup 44} erg s{sup -1}) population appear to have some kind of star formation contribution. This is significantly lower than for the Seyferts, especially if we take into account torus contamination at z > 1 where the majority of our X-ray QSOs lie. In addition, we observe a rapid drop of the percentage of starburst contribution as X-ray luminosity increases. This is consistent with the quenching of star formation by powerful QSOs, as predicted by the merger model, or with a time lag between the peak of star formation and QSO activity. We have tested the hypothesis that there should be a strong connection between X-ray obscuration and star formation but we do not find any association between X-ray column density and star formation rate both in the general population or the star-forming X-ray Seyferts. Our large compilation also allows us to report here the identification of 81 X-ray Bright Optically inactive Galaxies, 78 z > 3 X-ray sources, and eight Type-2 QSO candidates. Also, we have identified the highest redshift (z = 5.4135) X-ray-selected QSO with optical spectroscopy.

  20. Analysis of photographs and photo-paintings by energy-dispersive X-ray fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Neiva, Augusto Camara; Marcondes, Marli A.; Pinto, Herbert Prince Favero; Almeida, Paula Aline Durães

    2014-02-01

    A collection of Brazilian family photographs and photo-paintings from the beginning of the XX Century was analyzed by portable EDXRF (Energy-Dispersive X-Ray Fluorescence) spectroscopy. The spectrometer uses a Si-drift Amptek detector and an Oxford Cr-tube or an Oxford W-tube. For every region under analysis, spectra obtained with the W-tube were used to detect all the elements above Al, while the Cr-tube was used to obtain more accurate results for elements between Al and V. Thirty nine elements were identified in the photos, and the origin of the most important ones was discussed. These results can be used for cataloging, preservation and restoring procedures.

  1. Evaluation on determination of iodine in coal by energy dispersive X-ray fluorescence

    USGS Publications Warehouse

    Wang, B.; Jackson, J.C.; Palmer, C.; Zheng, B.; Finkelman, R.B.

    2005-01-01

    A quick and inexpensive method of relative high iodine determination from coal samples was evaluated. Energy dispersive X-ray fluorescence (EDXRF) provided a detection limit of about 14 ppm (3 times of standard deviations of the blank sample), without any complex sample preparation. An analytical relative standard deviation of 16% was readily attainable for coal samples. Under optimum conditions, coal samples with iodine concentrations higher than 5 ppm can be determined using this EDXRF method. For the time being, due to the general iodine concentrations of coal samples lower than 5 ppm, except for some high iodine content coal, this method can not effectively been used for iodine determination. More work needed to meet the requirement of determination of iodine from coal samples for this method. Copyright ?? 2005 by The Geochemical Society of Japan.

  2. Energy Dispersive X-Ray and Electrochemical Impedance Spectroscopies for Performance and Corrosion Analysis of PEMWEs

    NASA Astrophysics Data System (ADS)

    Steen, S. M., Iii; Zhang, F.-Y.

    2014-11-01

    Proton exchange membrane water electrolyzers (PEMWEs) are a promising energy storage technology due to their high efficiency, compact design, and ability to be used in a renewable energy system. Before they are able to make a large commercial impact, there are several hurdles facing the technology today. Two powerful techniques for both in-situ and ex- situ characterizations to improve upon their performance and better understand their corrosion are electrochemical impedance spectroscopy and energy dispersive x-ray spectroscopy, respectively. In this paper, the authors use both methods in order to characterize the anode gas diffusion layer (GDL) in a PEMWE cell and better understand the corrosion that occurs in the oxygen electrode during electrolysis.

  3. Angle-Dispersive X-ray Diffraction Study of Energetic Materials

    NASA Astrophysics Data System (ADS)

    Gump, Jared; Peiris, Suhithi

    2004-03-01

    Determining thermodynamic properties of energetic materials is important to the United States Navy for predicting the performance of new energetic formulations. This study uses angle dispersive x-ray diffraction performed at Cornell University's High Energy Synchrotron Source to obtain several isothermal equations of state of energetic materials, such as HMX and CL-20. Both non-hydrostatic and hydrostatic conditions were examined at room temperature. Pressures of up to 6GPa were achieved using diamond anvil cells. The bulk modulus and its first pressure derivative were determined by fitting the data to the Birch-Murnaghan equation of state formalism. Experimental data will be compared to ab-initio HF calculations and MD simulations.

  4. Atomic-scale chemical quantification of oxide interfaces using energy-dispersive X-ray spectroscopy

    SciTech Connect

    Lu, Ping; Van Benthem, Mark [Sandia National Laboratories, P.O. Box 5800, MS 1411, Albuquerque, New Mexico 87185-1411 (United States)] [Sandia National Laboratories, P.O. Box 5800, MS 1411, Albuquerque, New Mexico 87185-1411 (United States); Xiong, Jie; Jia, Quanxi [Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2013-04-29

    Atomic-scale quantification of chemical composition across oxide interfaces is important for understanding physical properties of epitaxial oxide nanostructures. Energy-dispersive X-ray spectroscopy (EDS) in an aberration-corrected scanning transmission electron microscope was used to quantify chemical composition across the interface of ferromagnetic La{sub 0.7}Sr{sub 0.3}MnO{sub 3} and antiferromagnetic BiFeO{sub 3} quantum structure. This research demonstrates that chemical composition at atomic columns can be quantified by Gaussian peak-fitting of EDS compositional profiles across the interface. Cation diffusion was observed at both A- and B-sublattice sites; and asymmetric chemical profiles exist across the interface, consistent with the previous studies.

  5. Studying Dark Energy, Black Holes and Cosmic Feedback at X-ray Wavelengths: NASA's Constellation-X Mission

    NASA Technical Reports Server (NTRS)

    Hornschemeier, A.

    2005-01-01

    Among the most important topics in modern astrophysics are the nature of the dark energy equation of state, the formation and evolution of supermassive black holes in concert with galaxy bulges, and the self-regulating symmetry imposed by both stellar and AGN feedback. All of these topics are readily addressed with observations at X-ray wavelengths. For instance, theoretical models predict that the majority (98%) of the energy and metal content in starburst superwinds exists in the hot million-degree gas. The Constellation-X observatory is being developed to perform spatially resolved high-resolution X-ray spectroscopy so that we may directly measure the absolute element abundances and velocities of this hot gas. This talk focuses on the driving science behind this mission, which is one of two flagship missions in NASA's Beyond Einstein program. A general overview of the observatory's capabilities and basic technology will also be given.

  6. The windowless energy dispersive X-ray detector: Prospects for a role in biological X-ray microanalysis

    Microsoft Academic Search

    1984-01-01

    Windowless energy dispersive detectors detect elements down to boron and carbon. They should be operated in a clean, high vacuum. Microphonics and other sources of electronic noise should be excluded since electronic noise is a major factor in spectrum degradation at low energies. A high bias voltage (100eV) reduces incomplete charge collection in the detector 'dead layer' which gives rise

  7. Rigorous quantitative elemental microanalysis by scanning electron microscopy/energy dispersive x-ray spectrometry (SEM/EDS) with spectrum processing by NIST DTSA-II

    NASA Astrophysics Data System (ADS)

    Newbury, Dale E.; Ritchie, Nicholas W. M.

    2014-09-01

    Quantitative electron-excited x-ray microanalysis by scanning electron microscopy/silicon drift detector energy dispersive x-ray spectrometry (SEM/SDD-EDS) is capable of achieving high accuracy and high precision equivalent to that of the high spectral resolution wavelength dispersive x-ray spectrometer even when severe peak interference occurs. The throughput of the SDD-EDS enables high count spectra to be measured that are stable in calibration and resolution (peak shape) across the full deadtime range. With this high spectral stability, multiple linear least squares peak fitting is successful for separating overlapping peaks and spectral background. Careful specimen preparation is necessary to remove topography on unknowns and standards. The standards-based matrix correction procedure embedded in the NIST DTSA-II software engine returns quantitative results supported by a complete error budget, including estimates of the uncertainties from measurement statistics and from the physical basis of the matrix corrections. NIST DTSA-II is available free for Java-platforms at: http://www.cstl.nist.gov/div837/837.02/epq/dtsa2/index.html).

  8. Positional characteristics of meter-decameter wavelength bursts associated with hard X-ray bursts

    NASA Technical Reports Server (NTRS)

    Kundu, M. R.; Gergely, T. E.; Kane, S. R.

    1982-01-01

    Isolated and grouped type III bursts have been observed in temporal association with impulsive hard X-ray bursts in the 26-154 keV range, down to frequencies as low as 30 MHz and out to a distance of 3.1 solar radii from the disk center. The bursts occurred in regions whose electron density may have been as much as 20 times higher than that of the Newkirk-Saito model. The present observations indicate that electron acceleration/injection occurs over a region covering a wide range of magnetic field lines. It is noted that, of the two gradual hard X-ray bursts observed in association with type IV bursts, one was accompanied by a type II event, while the other was not, although both exhibited the same characteristics. It is suggested that the gradual burst associated with a type IV only involved electrons which are trapped in the plasmoid which produces the meter-decameter emission, while another fraction of the population is trapped in the low-lying loops which produce the hard X-ray and centimeter radiation.

  9. A Multi-wavelength study of the Pulsar PSR B1929+10 and its X-ray trail

    E-print Network

    Becker, W; Jessner, A; Taam, R E; Jia, J J; Cheng, K S; Mignani, R; Pellizzoni, A; De Luca, A; Slowikowska, A; Caraveo, P A; Becker, Werner; Kramer, Michael; Jessner, Axel; Taam, Ronald E.; Jia, Jian J.; Cheng, Kwong S.; Mignani, Roberto; Pellizzoni, Alberto; Luca, Andrea de; Slowikowska, Agnieszka; Caraveo, Patrizia

    2005-01-01

    We report on the emission properties of PSR B1929+10 and its putative X-ray trail from a multi-wavelength study performed with XMM-Newton, the ESO NTT, the HST, the Effelsberg 100m Radio Telescope and the Jodrell Bank Radio Observatory. The XMM-Newton observations confirm the existence of the diffuse emission with a trail morphology lying in a direction opposite to the transverse motion of the pulsar. The trail has a length of ~15 arcmin. Its spectrum is non-thermal and produced by electron-synchrotron emission in the shock between the pulsar wind and the surrounding medium. Assuming that the electron lifetime against synchrotron cooling is comparable to the source transit time over the X-ray trail length, the magnetic field strength in the trail emitting region is inferred to be ~5 uG. Inspecting data from the Effelsberg 11cm radio continuum survey of the Galactic plane we discovered an elongated feature apparently coincident with the X-ray trail. The emission properties observed from PSR 1929+10 are found t...

  10. A Multi-wavelength study of the Pulsar PSR B1929+10 and its X-ray trail

    Microsoft Academic Search

    Werner Becker; Michael Kramer; Axel Jessner; Ronald E. Taam; Jian J. Jia; Kwong S. Cheng; Roberto Mignani; Alberto Pellizzoni; Andrea de Luca; Agnieszka Slowikowska; Patrizia Caraveo

    2005-01-01

    We report on the emission properties of PSR B1929+10 and its putative X-ray\\u000atrail from a multi-wavelength study performed with XMM-Newton, the ESO NTT, the\\u000aHST, the Effelsberg 100m Radio Telescope and the Jodrell Bank Radio\\u000aObservatory. The XMM-Newton observations confirm the existence of the diffuse\\u000aemission with a trail morphology lying in a direction opposite to the\\u000atransverse motion

  11. Analysis of energy dispersive x-ray diffraction profiles for material identification, imaging and system control

    NASA Astrophysics Data System (ADS)

    Cook, Emily Jane

    2008-12-01

    This thesis presents the analysis of low angle X-ray scatter measurements taken with an energy dispersive system for substance identification, imaging and system control. Diffraction measurements were made on illicit drugs, which have pseudo- crystalline structures and thus produce diffraction patterns comprising a se ries of sharp peaks. Though the diffraction profiles of each drug are visually characteristic, automated detection systems require a substance identification algorithm, and multivariate analysis was selected as suitable. The software was trained with measured diffraction data from 60 samples covering 7 illicit drugs and 5 common cutting agents, collected with a range of statistical qual ities and used to predict the content of 7 unknown samples. In all cases the constituents were identified correctly and the contents predicted to within 15%. Soft tissues exhibit broad peaks in their diffraction patterns. Diffraction data were collected from formalin fixed breast tissue samples and used to gen erate images. Maximum contrast between healthy and suspicious regions was achieved using momentum transfer windows 1.04-1.10 and 1.84-1.90 nm_1. The resulting images had an average contrast of 24.6% and 38.9% compared to the corresponding transmission X-ray images (18.3%). The data was used to simulate the feedback for an adaptive imaging system and the ratio of the aforementioned momentum transfer regions found to be an excellent pa rameter. Investigation into the effects of formalin fixation on human breast tissue and animal tissue equivalents indicated that fixation in standard 10% buffered formalin does not alter the diffraction profiles of tissue in the mo mentum transfer regions examined, though 100% unbuffered formalin affects the profile of porcine muscle tissue (a substitute for glandular and tumourous tissue), though fat is unaffected.

  12. X-ray Scattering Measurements of Particle Orientation in a Sheared Polymer/Clay Dispersion

    SciTech Connect

    Pujari, Saswati; Dougherty, Leah; Mobuchon, Christoph; Carreau, Pierre J.; Heuzey, Marie-Claude; Burghardt, Wesley R. (Ecole); (NWU); (Ecole)

    2012-01-20

    We report steady and transient measurements of particle orientation in a clay dispersion subjected to shear flow. An organically modified clay is dispersed in a Newtonian polymer matrix at a volume fraction of 0.02, using methods previously reported by Mobuchon et al. (Rheol Acta 46: 1045, 2007). In accord with prior studies, mechanical rheometry shows yield stress-like behavior in steady shear, while time dependent growth of modulus is observed following flow cessation. Measurements of flow-induced orientation in the flow-gradient plane of simple shear flow using small-angle and wide-angle X-ray scattering (SAXS and WAXS) are reported. Both SAXS and WAXS reveal increasing particle orientation as shear rate is increased. Partial relaxation of nanoparticle orientation upon flow cessation is well correlated with time-dependent changes in complex modulus. SAXS and WAXS data provide qualitatively similar results; however, some quantitative differences are attributed to differences in the length scales probed by these techniques.

  13. A general Monte Carlo simulation of energy-dispersive X-ray fluorescence spectrometers — Part 6. Quantification through iterative simulations

    NASA Astrophysics Data System (ADS)

    Schoonjans, Tom; Solé, Vicente Armando; Vincze, Laszlo; Sanchez del Rio, Manuel; Appel, Karen; Ferrero, Claudio

    2013-04-01

    A quantification tool for energy-dispersive X-ray fluorescence (ED-XRF) spectral data is presented, based on the application of Monte Carlo simulations in an iterative, inverse manner. Acting as an open-source plug-in to the widespread PyMca package, it provides users with a superior alternative to the fundamental parameter method based built-in quantification tool, taking into account higher order interactions, M-lines and cascade effects. Examples are shown demonstrating the usefulness of our implementation through data recorded at the synchrotron X-ray fluorescence microprobe installed at the HASYLAB Beamline L, Hamburg, Germany.

  14. ENERGY-DISPERSIVE, X-RAY REFLECTIVITY DENSITY MEASUREMENTS OF POROUS SIO2 XEROGELS

    EPA Science Inventory

    X-ray reflectivity has been used to nondestructively measure the density of thin, porous, SiO2-based xerogels. Critical angle, defined by total external reflection, was measured for multiple x-ray energies to correct for sample misalignment error in me determination of the densit...

  15. Polarity characterization by anomalous x-ray dispersion of ZnO films and GaN lateral polar structures

    SciTech Connect

    Shelton, Christopher T.; Sachet, Edward; Paisley, Elizabeth A.; Hoffmann, Marc P.; Rajan, Joseph; Collazo, Ramón; Sitar, Zlatko; Maria, Jon-Paul [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States)

    2014-01-28

    We demonstrate the use of anomalous x-ray scattering of constituent cations at their absorption edge, in a conventional Bragg-Brentano diffractometer, to measure absolutely and quantitatively the polar orientation and polarity fraction of unipolar and mixed polar wurtzitic crystals. In one set of experiments, the gradual transition between c+ and c? polarity of epitaxial ZnO films on sapphire as a function of MgO buffer layer thickness is monitored quantitatively, while in a second experiment, we map the polarity of a lateral polar homojunction in GaN. The dispersion measurements are compared with piezoforce microscopy images, and we demonstrate how x-ray dispersion and scanning probe methods can provide complementary information that can discriminate between polarity fractions at a material surface and polarity fractions averaged over the film bulk.

  16. THE SAP3 COMPUTER PROGRAM FOR QUANTITATIVE MULTIELEMENT ANALYSIS BY ENERGY DISPERSIVE X-RAY FLUORESCENCE

    SciTech Connect

    Nielson,, K. K.; Sanders,, R. W.

    1982-04-01

    SAP3 is a dual-function FORTRAN computer program which performs peak analysis of energy-dispersive x-ray fluorescence spectra and then quantitatively interprets the results of the multielement analysis. It was written for mono- or bi-chromatic excitation as from an isotopic or secondary excitation source, and uses the separate incoherent and coherent backscatter intensities to define the bulk sample matrix composition. This composition is used in performing fundamental-parameter matrix corrections for self-absorption, enhancement, and particle-size effects, obviating the need for specific calibrations for a given sample matrix. The generalized calibration is based on a set of thin-film sensitivities, which are stored in a library disk file and used for all sample matrices and thicknesses. Peak overlap factors are also determined from the thin-film standards, and are stored in the library for calculating peak overlap corrections. A detailed description is given of the algorithms and program logic, and the program listing and flow charts are also provided. An auxiliary program, SPCAL, is also given for use in calibrating the backscatter intensities. SAP3 provides numerous analysis options via seventeen control switches which give flexibility in performing the calculations best suited to the sample and the user needs. User input may be limited to the name of the library, the analysis livetime, and the spectrum filename and location. Output includes all peak analysis information, matrix correction factors, and element concentrations, uncertainties and detection limits. Twenty-four elements are typically determined from a 1024-channel spectrum in one-to-two minutes using a PDP-11/34 computer operating under RSX-11M.

  17. Energy dispersive X-ray fluorescence determination of cadmium in uranium matrix using Cd K? line excited by continuum

    NASA Astrophysics Data System (ADS)

    Dhara, Sangita; Misra, N. L.; Aggarwal, S. K.; Venugopal, V.

    2010-06-01

    An energy dispersive X-ray fluorescence method for determination of cadmium (Cd) in uranium (U) matrix using continuum source of excitation was developed. Calibration and sample solutions of cadmium, with and without uranium were prepared by mixing different volumes of standard solutions of cadmium and uranyl nitrate, both prepared in suprapure nitric acid. The concentration of Cd in calibration solutions and samples was in the range of 6 to 90 µg/mL whereas the concentration of Cd with respect to U ranged from 90 to 700 µg/g of U. From the calibration solutions and samples containing uranium, the major matrix uranium was selectively extracted using 30% tri-n-butyl phosphate in dodecane. Fixed volumes (1.5 mL) of aqueous phases thus obtained were taken directly in specially designed in-house fabricated leak proof Perspex sample cells for the energy dispersive X-ray fluorescence measurements and calibration plots were made by plotting Cd K? intensity against respective Cd concentration. For the calibration solutions not having uranium, the energy dispersive X-ray fluorescence spectra were measured without any extraction and Cd calibration plots were made accordingly. The results obtained showed a precision of 2% (1 ?) and the results deviated from the expected values by < 4% on average.

  18. X-Ray Spectra

    NSDL National Science Digital Library

    Neil Fetter

    2007-01-01

    In this activity, learners use simple materials to simulate the effect of X-rays in a safe way. Learners place a piece of window screen over a box and a cardboard pattern on top of the screen. They sprinkle sand over the area of the box. The sand simulates X-rays passing through the screen to the bottom of the box, except where they are blocked by the cardboard. Use this activity to demonstrate how X-rays create an image, including "soft" and shorter wavelength X-rays as well as X-rays from space.

  19. The application of a microstrip gas counter to energy-dispersive x-ray fluorescence analysis

    SciTech Connect

    Veloso, J.F.C.A.; Santos, J.M.F. dos; Conde, C.A.N. [Univ. de Coimbra (Portugal). Dept. de Fisica; Morgado, R.E. [Los Alamos National Lab., NM (United States)

    1996-07-01

    Performance characteristics of a microstrip gas counter operated as a x-ray fluorescence spectrometer are reported. Gas amplification as a function of microstrip anode-cathode voltage was measured, and the breakdown threshold voltage was determined in pure xenon. The detector temporal stability and the effect of gas purity were assessed. Energy resolution and linearity, detection efficiency, and uniformity of spatial response in the 2- to 60-keV x-ray energy range were determined from the pulse-height distributions of the fluorescence x-ray spectra induced in a variety of single- and multi-element sample materials. Energy resolution similar to conventional proportional counters was achieved at 6 keV.

  20. New reference and test materials for the characterization of energy dispersive X-ray spectrometers at scanning electron microscopes.

    PubMed

    Rackwitz, Vanessa; Krumrey, Michael; Laubis, Christian; Scholze, Frank; Hodoroaba, Vasile-Dan

    2015-04-01

    Checking the performance of energy dispersive X-ray spectrometers as well as validation of the results obtained with energy dispersive X-ray spectrometry (EDX) at a scanning electron microscope (SEM) involve the use of (certified) reference and dedicated test materials. This paper gives an overview on the test materials mostly employed by SEM/EDX users and accredited laboratories as well as on those recommended in international standards. The new BAM reference material EDS-CRM, which is currently in the process of certification, is specifically designed for the characterization of EDS systems at a SEM through calibration of the spectrometer efficiency in analytical laboratories in a simple manner. The certification of the spectra by means of a reference EDS is described. The focus is on the traceability of EDS efficiency which is ensured by measurements of the absolute detection efficiency of silicon drift detectors (SDD) and Si(Li) detectors at the laboratory of the PTB using the electron storage ring BESSY II as a primary X-ray source standard. A new test material in development at BAM for testing the performance of an EDS in the energy range below 1 keV is also briefly presented. PMID:25326887

  1. EVOLUTION OF X-RAY AND FAR-ULTRAVIOLET DISK-DISPERSING RADIATION FIELDS

    SciTech Connect

    Ingleby, Laura; Calvet, Nuria; Miller, Jon; Bergin, Edwin; Hartmann, Lee [Department of Astronomy, University of Michigan, 830 Dennison Building, 500 Church Street, Ann Arbor, MI 48109 (United States); Hernandez, Jesus; Briceno, Cesar [Centro de Investigaciones de Astronomia (CIDA), Merida, 5101-A (Venezuela, Bolivarian Republic of); Espaillat, Catherine, E-mail: lingleby@umich.edu, E-mail: ncalvet@umich.edu, E-mail: jonmm@umich.edu, E-mail: ebergin@umich.edu, E-mail: lhartm@umich.edu, E-mail: jesush@cida.ve, E-mail: briceno@cida.ve, E-mail: cespaillat@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-78, Cambridge, MA 02138 (United States)

    2011-04-15

    We present new X-ray and far-ultraviolet (FUV) observations of T Tauri stars covering the age range 1-10 Myr. Our goals are to observationally constrain the intensity of radiation fields responsible for evaporating gas from the circumstellar disk and to assess the feasibility of current photoevaporation models, focusing on X-ray and UV radiation. We greatly increase the number of 7-10 Myr old T Tauri stars observed in X-rays by including observations of the well-populated 25 Ori aggregate in the Orion OB1a subassociation. With these new 7-10 Myr objects, we confirm that X-ray emission remains constant from 1 to 10 Myr. We also show, for the first time, observational evidence for the evolution of FUV radiation fields with a sample of 56 accreting and non-accreting young stars spanning 1 Myr to 1 Gyr. We find that the FUV emission decreases on timescales consistent with the decline of accretion in classical T Tauri stars until reaching the chromospheric level in weak T Tauri stars and debris disks. Overall, we find that the observed strength of high-energy radiation is consistent with that required by photoevaporation models to dissipate the disks in timescales of approximately 10 Myr. Finally, we find that the high-energy fields that affect gas evolution are not similarly affecting dust evolution; in particular, we find that disks with inner clearings, transitional disks, have similar levels of FUV emission as full disks.

  2. A microsphere-based short-wavelength recombination x-ray laser

    SciTech Connect

    Valeo, E.J.; Cowley, S.C.

    1992-04-01

    We describe a scheme for obtaining very short wavelengths ({lambda} {similar to} 10{Angstrom}) in recombination lasers. The rapid cooling rates necessary to achieve population inversion during recombination are attained by adiabatic expansion of sub micron spheres. The lasing region is made up of many such spheres. The spheres are heated impulsively by a powerful picosecond laser. First, they ionize, then as they expand, they cool and recombine. We have calculated the optimum sphere size and initial temperature for maximum gain in the n = 3 to n = 2 transition of hydrogen-like ions of elements with atomic numbers, Z, between 10 and 30. Gain of about 10{sup 3}cm{sup {minus}1} is calculated in aluminum at 38.8{Angstrom}. Gain rapidly decreases with Z so that gain in titanium at 13.6{Angstrom} is about 40 cm{minus}1. We have calculated the required pump laser intensity and found it to be attainable with current lasers. The propagation of the pump through the gas'' of spheres is considered and the problems arising from pump scattering by the spheres are discussed.

  3. A microsphere-based short-wavelength recombination x-ray laser

    SciTech Connect

    Valeo, E.J.; Cowley, S.C.

    1992-04-01

    We describe a scheme for obtaining very short wavelengths ({lambda} {similar_to} 10{Angstrom}) in recombination lasers. The rapid cooling rates necessary to achieve population inversion during recombination are attained by adiabatic expansion of sub micron spheres. The lasing region is made up of many such spheres. The spheres are heated impulsively by a powerful picosecond laser. First, they ionize, then as they expand, they cool and recombine. We have calculated the optimum sphere size and initial temperature for maximum gain in the n = 3 to n = 2 transition of hydrogen-like ions of elements with atomic numbers, Z, between 10 and 30. Gain of about 10{sup 3}cm{sup {minus}1} is calculated in aluminum at 38.8{Angstrom}. Gain rapidly decreases with Z so that gain in titanium at 13.6{Angstrom} is about 40 cm{minus}1. We have calculated the required pump laser intensity and found it to be attainable with current lasers. The propagation of the pump through the ``gas`` of spheres is considered and the problems arising from pump scattering by the spheres are discussed.

  4. Residual strain gradient determination in metal matrix composites by synchrotron X-ray energy dispersive diffraction

    NASA Technical Reports Server (NTRS)

    Kuntz, Todd A.; Wadley, Haydn N. G.; Black, David R.

    1993-01-01

    An X-ray technique for the measurement of internal residual strain gradients near the continuous reinforcements of metal matrix composites has been investigated. The technique utilizes high intensity white X-ray radiation from a synchrotron radiation source to obtain energy spectra from small (0.001 cu mm) volumes deep within composite samples. The viability of the technique was tested using a model system with 800 micron Al203 fibers and a commercial purity titanium matrix. Good agreement was observed between the measured residual radial and hoop strain gradients and those estimated from a simple elastic concentric cylinders model. The technique was then used to assess the strains near (SCS-6) silicon carbide fibers in a Ti-14Al-21Nb matrix after consolidation processing. Reasonable agreement between measured and calculated strains was seen provided the probe volume was located 50 microns or more from the fiber/matrix interface.

  5. Measurement of mass attenuation coefficients of biological materials by energy dispersive X-ray fluorescence spectrometry

    Microsoft Academic Search

    N. Ekinci; N. Astam

    2007-01-01

    The mass attenuation coefficients for cornea taken from keratitis patient and soft contact lens (-1.75, -3.75, -4 dioptres), leiomyomata uteri and uterus were measured in the X-ray energy (5.9keV) using a SiLi detector and Fe55 annular source. Full details of the experimental method, experimental set up, the procedure of sample preparation and the results within estimated error are presented. Energy

  6. Evaluating the presence of titanium in XIX-century Brazilian steels by energy-dispersive X-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Neiva, Augusto Camara; Pinto, Herbert Prince Favero; Landgraf, Fernando José Gomes

    2014-02-01

    Ores, pig iron and steel pieces from the XIX Century ironworks Royal St. John of Ipanema Iron Foundry (Real Fábrica de Ferro São João do Ipanema), in Iperó, Brazil, were analyzed by Energy-Dispersive X-Ray Fluorescence (EDXRF) spectroscopy, with the aim of investigating the presence of deleterious elements as Ti and P in the minerals and in the resulting products. Analytical modifications made in order to improve the detection limits for Ti and P are discussed. Both elements were found in the raw material and in the products, but large differences in chemical composition were found in different samples or regions of samples.

  7. Benzyne-functionalized graphene and graphite characterized by Raman spectroscopy and energy dispersive X-ray analysis.

    PubMed

    Magedov, Igor V; Frolova, Lilia V; Ovezmyradov, Mekan; Bethke, Donald; Shaner, Eric A; Kalugin, Nikolai G

    2013-04-01

    The benzyne functionalization of chemical vapor deposition grown large area graphene and graphite was performed using a mixture of o-trimethylsilylphenyl triflate and cesium fluoride that react with the carbon surface. The reaction requires at least 2 days of treatment before the appearance of Raman and energy-dispersive X-ray spectral signatures that verify modification. Raman spectra of modified graphene and graphite show a rich structure of lines corresponding to C=C-C, C-H, and low frequency modes of surface-attached benzyne rings. PMID:23505324

  8. Enhanced quantification for 3D energy dispersive spectrometry: going beyond the limitation of large volume of X-ray emission.

    PubMed

    Burdet, Pierre; Hébert, Cécile; Cantoni, Marco

    2014-10-01

    This paper presents a method developed to quantify three-dimensional energy dispersive spectrometry (3D EDS) data with voxel size smaller than the volume from which X-rays are emitted. The influence of the neighboring voxels is corrected by applying recursively a complex quantification, improving thereby the accuracy of the quantification of critically small features. The enhanced quantification method is applied to simulated and measured data. A systematic improvement is obtained compared with classical quantification, proving the concept and the prospect of this method. PMID:24960631

  9. Dense close-packed phase of tin above 157 GPa observed experimentally via angle-dispersive x-ray diffraction

    NASA Astrophysics Data System (ADS)

    Salamat, Ashkan; Garbarino, Gaston; Dewaele, Agnès; Bouvier, Pierre; Petitgirard, Sylvain; Pickard, Chris J.; McMillan, Paul F.; Mezouar, Mohamed

    2011-10-01

    A hexagonal close-packed (P63/mmc) phase of the group 14 element Sn has been observed using angle-dispersive x-ray diffraction. The phase transition proceeds from bcc?hcp above 157 GPa at 298 K via a first-order pathway, accompanied by a small decrease in unit-cell volume (0.2%). Both phases coexist up to 194 GPa. Ab initio random structure search calculations confirm that the hcp phase is the only candidate for another polymorph of Sn occurring in this pressure range, and predict a return to the bcc structure above 1.3 TPa.

  10. Crystals for astronomical X-ray spectroscopy

    NASA Technical Reports Server (NTRS)

    Burek, A.

    1976-01-01

    Crystal spectrometric properties and the factors that affect their measurement are discussed. Theoretical and experimental results on KAP are summarized and theoretical results based on the dynamical theory of X-ray diffraction are given for the acid phthalates as well as for the commonly used planes of ADP, PET and EDDT. Anomalous dispersion is found to be important for understanding the details of crystal Bragg reflection properties at long X-ray wavelengths and some important effects are pointed out. The theory of anomalous dispersion is applied to explain the anomalous reflectivity exhibited by KAP at 23.3 A.

  11. New parallel wavelength-dispersive spectrometer based on scanning electron microscope.

    PubMed

    Erko, Alexei; Firsov, Alexander; Gubzhokov, Renat; Bjeoumikhov, Anjuar; Günther, Andreas; Langhoff, Norbert; Bretschneider, Mario; Höhn, Yvonne; Wedell, Reiner

    2014-07-14

    A new wavelength - dispersive X-ray spectrometer for scanning electron microscopy (SEM) has been developed. This spectrometer can cover an energy range from 50 eV to 1120 eV by using an array made of seventeen reflection zone plates. Soft X-ray emission spectra of simple elements of Li, Be, B, C, N, Ti, V, O, Cr, Mn, Fe, Co, Ni, Cu, Zn and Ga were measured. The overall energy resolving power on the order of E/?E ~80 to 160 has been demonstrated. Spectrometer with 200 reflection zone plates has been used as a multi-channel analyser in the energy range of 100 - 1000 eV for quasi - continuous spectra measurements. The predicted energy-resolving power on the order of E/?E = 50 has been achieved in the entire energy range. PMID:25090506

  12. Detector solid angle formulas for use in x-ray energy dispersive spectrometry.

    SciTech Connect

    Zaluzec, N. J.; Materials Science Division

    2009-01-01

    With the advent of silicon drift X-ray detectors, a range of new geometries has become possible in electron optical columns. Because of their compact size, these detectors can potentially achieve high geometrical collection efficiencies; however, using traditional approximations detector solid angle calculations rapidly break down and at times can yield nonphysical values. In this article we present generalized formulas that can be used to calculate the variation in detection solid angle for contemporary Si(Li) as well as new silicon drift configurations.

  13. Methodology toward 3D micro X-ray fluorescence imaging using an energy dispersive charge-coupled device detector.

    PubMed

    Garrevoet, Jan; Vekemans, Bart; Tack, Pieter; De Samber, Björn; Schmitz, Sylvia; Brenker, Frank E; Falkenberg, Gerald; Vincze, Laszlo

    2014-12-01

    A new three-dimensional (3D) micro X-ray fluorescence (?XRF) methodology based on a novel 2D energy dispersive CCD detector has been developed and evaluated at the P06 beamline of the Petra-III storage ring (DESY) in Hamburg, Germany. This method is based on the illumination of the investigated sample cross-section by a horizontally focused beam (vertical sheet beam) while fluorescent X-rays are detected perpendicularly to the sheet beam by a 2D energy dispersive (ED) CCD detector allowing the collection of 2D cross-sectional elemental images of a certain depth within the sample, limited only by signal self-absorption effects. 3D elemental information is obtained by a linear scan of the sample in the horizontal direction across the vertically oriented sheet beam and combining the detected cross-sectional images into a 3D elemental distribution data set. Results of the 3D ?XRF analysis of mineral inclusions in natural deep Earth diamonds are presented to illustrate this new methodology. PMID:25346101

  14. Determination of trace elements in Syrian medicinal plants and their infusions by energy dispersive X-ray fluorescence and total reflection X-ray fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Khuder, A.; Sawan, M. Kh.; Karjou, J.; Razouk, A. K.

    2009-07-01

    X-ray fluorescence (XRF) and total-reflection X-ray fluorescence (TXRF) techniques suited well for a multi-element determination of K, Ca, Mn, Fe, Cu, Zn, Rb, and Sr in some Syrian medicinal plant species. The accuracy and the precision of both techniques were verified by analyzing the Standard Reference Materials (SRM) peach-1547 and apple leaves-1515. A good agreement between the measured concentrations of the previously mentioned elements and the certified values were obtained with errors less than 10.7% for TXRF and 15.8% for XRF. The determination of Br was acceptable only by XRF with an error less than 24%. Furthermore, the XRF method showed a very good applicability for the determination of K, Ca, Mn, Fe, Cu, Zn, Rb, Sr, and Br in infusions of different Syrian medicinal plant species, namely anise ( Anisum vulgare), licorice root ( Glycyrrhiza glabra), and white wormwood ( Artemisia herba-alba).

  15. Determination of selenium at trace levels in geologic materials by energy-dispersive X-ray fluorescence spectrometry

    USGS Publications Warehouse

    Wahlberg, J.S.

    1981-01-01

    Low levels of selenium (0.1-500 ppm) in both organic and inorganic geologic materials can be semiquantitatively measured by isolating Se as a thin film for presentation to an energy-dispersive X-ray fluorescence spectrometer. Suitably pulverized samples are first digested by fusing with a mixture of Na2CO3 and Na2O2. The fusion cake is dissolved in distilled water, buffered with NH4Cl, and filtered to remove Si and the R2O3 group. A carrier solution of Na2TeO4, plus solid KI, hydrazine sulfate and Na2SO3, is added to the filtrate. The solution is then vacuum-filtered through a 0.45-??m pore-size filter disc. The filter, with the thin film of precipitate, is supported between two sheets of Mylar?? film for analysis. Good agreement is shown between data reported in this study and literature values reported by epithermal neutron-activation analysis and spectrofluorimetry. The method can be made quantitative by utilizing a secondary precipitation to assure complete recovery of the Se. The X-ray method offers fast turn-around time and a reasonably high production rate. ?? 1981.

  16. Photometric study of single-shot energy-dispersive x-ray diffraction at a laser plasma facility

    SciTech Connect

    Hoidn, O. R.; Seidler, G. T., E-mail: seidler@uw.edu [Physics Department, University of Washington, Seattle, Washington 98195-1560 (United States)

    2014-01-15

    The low repetition rates and possible shot-to-shot variations in laser-plasma studies place a high value on single-shot diagnostics. For example, white-beam scattering methods based on broadband backlighter x-ray sources are used to determine changes in the structure of laser-shocked crystalline materials by the evolution of coincidences of reciprocal lattice vectors and kinematically allowed momentum transfers. Here, we demonstrate that white-beam techniques can be extended to strongly disordered dense plasma and warm dense matter systems where reciprocal space is only weakly structured and spectroscopic detection is consequently needed to determine the static structure factor and thus, the ion-ion radial distribution function. Specifically, we report a photometric study of energy-dispersive x-ray diffraction (ED-XRD) for structural measurement of high energy density systems at large-scale laser facilities such as OMEGA and the National Ignition Facility. We find that structural information can be obtained in single-shot ED-XRD experiments using established backlighter and spectrometer technologies.

  17. Effect of x-ray energy dispersion in digital subtraction imaging at the iodine K-edge--a Monte Carlo study.

    PubMed

    Prino, F; Ceballos, C; Cabal, A; Sarnelli, A; Gambaccini, M; Ramello, L

    2008-01-01

    The effect of the energy dispersion of a quasi-monochromatic x-ray beam on the performance of a dual-energy x-ray imaging system is studied by means of Monte Carlo simulations using MCNPX (Monte Carlo N-Particle eXtended) version 2.6.0. In particular, the case of subtraction imaging at the iodine K-edge, suitable for angiographic imaging application, is investigated. The average energies of the two beams bracketing the iodine K-edge are set to the values of 31.2 and 35.6 keV corresponding to the ones obtained with a compact source based on a conventional x-ray tube and a mosaic crystal monochromator. The energy dispersion of the two beams is varied between 0 and 10 keV of full width at half-maximum (FWHM). The signal and signal-to-noise ratio produced in the simulated images by iodine-filled cavities (simulating patient vessels) drilled in a PMMA phantom are studied as a function of the x-ray energy dispersion. The obtained results show that, for the considered energy separation of 4.4 keV, no dramatic deterioration of the image quality is observed with increasing x-ray energy dispersion up to a FWHM of about 2.35 keV. The case of different beam energies is also investigated by means of fast simulations of the phantom absorption. PMID:18293556

  18. Analysis of aqueous and organic fission-product solutions by energy-dispersive x-ray fluorescence

    SciTech Connect

    Brooksbank, R.D.; Stewart, J.H. Jr.

    1981-01-01

    Because of a revival of interest in reprocessing spent nuclear reactor fuel, ORNL is re-evaluating existing data on extractions. Organic degradation products and new organic extractant systems must also be investigated. Analysis of these solutions present several problems for the analytical chemist. Conventional wet chemical techniques usually require aqueous solutions. Organic solutions must be stripped or wet ashed to convert them to an aqueous system. Stripping is not always quantitative, and the high phosphorus content of organic extractants makes wet ashing difficult. Radiolysis degrades many organic solutions. In aqueous solutions, low acid concentrations cause Pu to polymerize and Zr and Mo to form colloids or precipitate; therefore, sample pretreatment becomes necessary. Energy dispersive x-ray fluorescence (XRF) is a multi-element technique, unaffected by chemical states, capable of analyzing both aqueous and organic solutions. Thie technique has been applied to the determination of U, Pu, Th, Mo, Zr and Re in cold flow sheet development.

  19. Dendrochemical patterns of calcium, zinc, and potassium related to internal factors detected by energy dispersive X-ray fluorescence (EDXRF).

    PubMed

    Smith, Kevin T; Balouet, Jean Christophe; Shortle, Walter C; Chalot, Michel; Beaujard, François; Grudd, Håkan; Vroblesky, Don A; Burken, Joel G

    2014-01-01

    Energy dispersive X-ray fluorescence (EDXRF) provides highly sensitive and precise spatial resolution of cation content in individual annual growth rings in trees. The sensitivity and precision have prompted successful applications to forensic dendrochemistry and the timing of environmental releases of contaminants. These applications have highlighted the need to distinguish dendrochemical effects of internal processes from environmental contamination. Calcium, potassium, and zinc are three marker cations that illustrate the influence of these processes. We found changes in cation chemistry in tree rings potentially due to biomineralization, development of cracks or checks, heartwood/sapwood differentiation, intra-annual processes, and compartmentalization of infection. Distinguishing internal from external processes that affect dendrochemistry will enhance the value of EDXRF for both physiological and forensic investigations. PMID:24034830

  20. Bulk and trace element analysis of spices: the applicability of k0-standardization and energy dispersive X-ray fluorescence.

    PubMed

    Jayasekera, Ranjith; Freitas, Maria C; Araújo, Maria F

    2004-01-01

    Methodology has been developed for the bulk and trace element analysis of spices such as curry powder and turmeric powder originated from Sri Lanka by the k0-standardization method (INAA-k0) and by energy dispersive X-ray fluorescence (EDXRF). SRM 1572 citrus leaves was used to check the accuracy of the results obtained by the two nuclear techniques. The elements determined quantitatively in these matrices by the EDXRF analysis were bromine, calcium, copper, iron, potassium, magnesium, manganese, phosphorus, rubidium, sulphur, strontium and zinc. The results obtained by the two techniques are comparable, although a few inconsistencies were detected, requiring adequate attention for their correction, whenever possible, in future studies. PMID:15139383

  1. Energy-dispersive X-ray fluorescence analysis of moss and soil from abandoned mining of Pb-Zn ores.

    PubMed

    Koz, B

    2014-09-01

    This research investigates heavy metal pollution around one of the most important mining areas in Turkey, the Sebinkarahisar (Giresun) lead-zinc mining, by means of analyzing moss and soil samples collected in the neighborhood of the copper mining at different distances. Energy dispersive X-ray fluorescence spectrometry (Epsilon 5, PANalytical, Almelo, The Netherlands) is utilized in the experiments. The results have indicated that the both moss and soil samples contain aluminum, vanadium, chromium, manganese, iron, nickel, copper, zinc, arsenic, barium, cerium, tungsten, and lead. The comparison of the heavy metal concentrations with the typical measurements in the world and with the limit values for the human health has revealed the critical heavy metal pollution levels in the region. The possible consequences of these results are briefly discussed from the point of potential hazards to ecology and human health. PMID:24788924

  2. X-ray beamsplitter

    DOEpatents

    Ceglio, Natale M. (Livermore, CA); Stearns, Daniel S. (Mountain View, CA); Hawryluk, Andrew M. (Modesto, CA); Barbee, Jr., Troy W. (Palo Alto, CA)

    1989-01-01

    An x-ray beamsplitter which splits an x-ray beam into two coherent parts by reflecting and transmitting some fraction of an incident beam has applications for x-ray interferometry, x-ray holography, x-ray beam manipulation, and x-ray laser cavity output couplers. The beamsplitter is formed of a wavelength selective multilayer thin film supported by a very thin x-ray transparent membrane. The beamsplitter resonantly transmits and reflects x-rays through thin film interference effects. A thin film is formed of 5-50 pairs of alternate Mo/Si layers with a period of 20-250 A. The support membrane is 10-200 nm of silicon nitride or boron nitride. The multilayer/support membrane structure is formed across a window in a substrate by first forming the structure on a solid substrate and then forming a window in the substrate to leave a free-standing structure over the window.

  3. X-ray beamsplitter

    DOEpatents

    Ceglio, N.M.; Stearns, D.G.; Hawryluk, A.M.; Barbee, T.W. Jr.

    1987-08-07

    An x-ray beamsplitter which splits an x-ray beam into two coherent parts by reflecting and transmitting some fraction of an incident beam has applications for x-ray interferometry, x-ray holography, x-ray beam manipulation, and x-ray laser cavity output couplers. The beamsplitter is formed of a wavelength selective multilayer thin film supported by a very thin x-ray transparent membrane. The beamsplitter resonantly transmits and reflects x-rays through thin film interference effects. A thin film is formed of 5--50 pairs of alternate Mo/Si layers with a period of 20--250 A. The support membrane is 10--200 nm of silicon nitride or boron nitride. The multilayer/support membrane structure is formed across a window in a substrate by first forming the structure on a solid substrate and then forming a window in the substrate to leave a free-standing structure over the window. 6 figs.

  4. X-ray microprobe system for XRF analysis and spectroscopy at SPring-8 BL39XU.

    PubMed

    Hayakawa, S; Goto, S; Shoji, T; Yamada, E; Gohshi, Y

    1998-05-01

    An X-ray microprobe system for X-ray fluorescence (XRF) analysis and spectroscopy has been developed at SPring-8 BL39XU; it comprises an X-ray focusing or collimation system, energy-dispersive (ED) and wavelength-dispersive (WD) XRF spectrometers, and a sample-scanning system. The conventional ED spectrometer will be utilized for qualitative and quantitative trace-element analysis, and the WD spectrometer will be used both for trace-element analysis and XRF spectroscopy. A combination of monochromated undulator radiation and the WD spectrometer will enable resonant XRF spectroscopy using brilliant hard X-ray undulator radiation. PMID:15263763

  5. Effect of x-ray energy dispersion in digital subtraction imaging at the iodine K-edge--A Monte Carlo study

    E-print Network

    Ramello, Luciano

    Effect of x-ray energy dispersion in digital subtraction imaging at the iodine K-edge--A Monte at the iodine K-edge, suitable for angiographic imaging application, is investigated. The average energies of the two beams bracketing the iodine K-edge are set to the values of 31.2 and 35.6 keV corresponding

  6. Energy dispersive X-ray diffraction potentiality in the field of cultural heritage: simultaneous structural and elemental analysis of various artefacts.

    PubMed

    Caponetti, Eugenio; Caminiti, Ruggero; Chillura Martino, Delia; Saladino, Maria Luisa

    2007-07-01

    The applicability of an Energy Dispersive X-ray Diffractometer to some technical questions in the field of Cultural Heritage is presented. This diffractometer, equipped with a white source, has been utilized for the structural and elemental analysis of some items having different nature. Given its design, the instrument allows to collect data from samples as big as a book or a little more. Samples, without collection of any portion and without any preliminary preparation, have been placed in the instrument and spectra have been collected in a wide energy range that contains X-ray fluorescence and diffraction features. In all cases, data acquired in air and in a non destructive way were reliable and their collection was fast. Fluorescence and X-ray diffraction information, when possible, have been compared with those obtained by XRF micro-analysis and by an Angle Dispersive X-ray Diffractometer equipped with a Cu X-ray source. By using the last two techniques, data have been collected from small areas of the samples. PMID:17867533

  7. [Chemical composition analysis of bluish-white porcelain unearthed from Fanchang kiln, Anhui province by wave disperse X-ray fluorescence].

    PubMed

    Yang, Yu-zhang; Zhang, Ju-zhong; Zan, Yi

    2010-08-01

    Fanchang kiln was the earliest Chinese bluish-white porcelain kiln which first fired this special porcelain class as early as in Five Dynasties (AD 907-960). However, this important kiln declined rapidly in the middle North Song dynasty (AD 1023-1085). As to the decline reason, it is still not clearly identified till now. In order to find the truth, wavelength-dispersive X-ray fluorescence (WDXRF) was used to determine the elemental abundance patterns of its porcelain bodies in Five Dynasties, the early North Song dynasty and the middle North Song dynasty. The analytical results indicate that the chemical compositions of major, minor and trace elements in porcelain bodies changed greatly in the middle North Song dynasty. Combined with the results of INAA and glaze study, this change in elemental composition should be caused by the change in porcelain raw materials or body-making crafts. Meanwhile, it was just this change that led to the quality decline of raw material and rapid collapse of Fan-chang kiln in the middle North Song dynasty shortly after its establishment. PMID:20939361

  8. MULTI-WAVELENGTH STUDIES OF SPECTACULAR RAM PRESSURE STRIPPING OF A GALAXY: DISCOVERY OF AN X-RAY ABSORPTION FEATURE

    SciTech Connect

    Gu, Liyi; Makishima, Kazuo [Research Center for the Early Universe, School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)] [Research Center for the Early Universe, School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Yagi, Masafumi [Optical and Infrared Astronomy Division, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)] [Optical and Infrared Astronomy Division, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Nakazawa, Kazuhiro [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)] [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Yoshida, Michitoshi [Hiroshima Astrophysical Science Center, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan)] [Hiroshima Astrophysical Science Center, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Fujita, Yutaka [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043 (Japan)] [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043 (Japan); Hattori, Takashi [Subaru Telescope, National Astronomical Observatory of Japan, 650 North A'Ohoku Place, Hilo, HI 96720 (United States)] [Subaru Telescope, National Astronomical Observatory of Japan, 650 North A'Ohoku Place, Hilo, HI 96720 (United States); Akahori, Takuya, E-mail: lygu@juno.phys.s.u-tokyo.ac.jp [Sydney Institute for Astronomy, School of Physics, The University of Sydney, NSW 2006 (Australia)] [Sydney Institute for Astronomy, School of Physics, The University of Sydney, NSW 2006 (Australia)

    2013-11-10

    We report the detection of an X-ray absorption feature near the galaxy M86 in the Virgo cluster. The absorber has a column density of 2-3 × 10{sup 20} cm{sup –2}, and its position coincides with the peak of an intracluster H I cloud which was removed from the galaxy NGC 4388 presumably by ram pressure. These results indicate that the H I cloud is located in front of M86 along the line-of-sight, and suggest that the stripping was primarily created by an interaction between NGC 4388 and the hot plasmas of the Virgo cluster, not the M86 halo. By calculating an X-ray temperature map, we further detected an X-ray counterpart of the H I cloud up to ?3' south of M86. It has a temperature of 0.89 keV and a mass of ?4.5 × 10{sup 8} M {sub ?}, exceeding the estimated H I gas mass. The high hot-to-cold gas ratio in the cloud indicates a significant evaporation of the H I gas, probably by thermal conduction from the hotter cluster plasma with a sub-Spitzer rate.

  9. Mapping the Ionization State of Laser-Irradiated Ar Gas Jets With Multi-Wavelength Monochromatic X-Ray Imaging

    SciTech Connect

    Kugland, N L; Doppner, T; Kemp, A; Schaeffer, D; Glenzer, S H; Niemann, C

    2010-04-08

    Two-dimensional monochromatic images of fast-electron stimulated Ar K{alpha} and He-{alpha} x-ray self-emission have recorded a time-integrated map of the extent of Ar{sup {approx}6+} and Ar{sup 16+} ions, respectively, within a high density (10{sup 20} cm{sup -3} atomic density) Ar plasma. This plasma was produced by irradiating a 2 mm wide clustering Ar gas jet with an ultra-high intensity (10{sup 19} W/cm{sup 2}, 200 fs) Ti:Sapphire laser operating at 800 nm. Spherically bent quartz crystals in the 200 (for K{alpha}) and 201 (for He-{alpha}) planes were used as near-normal incidence reflective x-ray optics. We see that a large (830 {micro}m long) region of plasma emits K{alpha} primarily along the laser axis, while the He-{alpha} emission is confined to smaller hot spot (230 {micro}m long) region that likely corresponds to the focal volume of the f/8 laser beam. X-ray spectra from a Bragg spectrometer operating in the von Hamos geometry, which images in one dimension, indicate that the centroids of the K{alpha} and He-{alpha} emission regions are separated by approximately 330 {micro}m along the laser axis.

  10. Time- and wavelength-resolved luminescence evaluation of several types of scintillators using streak camera system equipped with pulsed X-ray source

    NASA Astrophysics Data System (ADS)

    Furuya, Yuki; Yanagida, Takayuki; Fujimoto, Yutaka; Yokota, Yuui; Kamada, Kei; Kawaguchi, Noriaki; Ishizu, Sumito; Uchiyama, Koro; Mori, Kuniyoshi; Kitano, Ken; Nikl, Martin; Yoshikawa, Akira

    2011-04-01

    To design new scintillating materials, it is very important to understand detailed information about the events, which occurred during the excitation and emission processes under the ionizing radiation excitation. We developed a streak camera system equipped with picosecond pulsed X-ray source to observe time- and wavelength-resolved scintillation events. In this report, we test the performance of this new system using several types of scintillators including bulk oxide/halide crystals, transparent ceramics, plastics and powders. For all samples, the results were consistent with those reported previously. The results demonstrated that the developed system is suitable for evaluation of the scintillation properties.

  11. Photometric study of single-shot energy-dispersive X-ray diffraction at a laser plasma facility

    E-print Network

    Hoidn, O R

    2013-01-01

    The low repetition rates and possible shot-to-shot variations in laser-plasma studies place a high value on single-shot diagnostics. For example, white-beam scattering methods based on broadband backlighter x-ray sources are used to determine changes in the structure of laser-shocked crystalline materials by the evolution of coincidences of reciprocal lattice vectors and kinematically-allowed momentum transfers. Here, we demonstrate that white-beam techniques can be extended to strongly-disordered dense plasma and warm dense matter (WDM) systems where reciprocal space is only weakly structured and spectroscopic detection is consequently needed to determine the static structure factor and thus the ion-ion radial distribution function. Specifically, we report a photometric study of energy-dispersive diffraction (ED-XRD) for structural measurement of high energy density systems at large-scale laser facilities such as OMEGA and the National Ignition Facility. We find that structural information can be obtained in...

  12. Chemometric methods for the quantification of crystalline tacrolimus in solid dispersion by powder X-ray diffractrometry.

    PubMed

    Siddiqui, Akhtar; Rahman, Ziyaur; Bykadi, Srikant; Khan, Mansoor A

    2014-09-01

    The objective of this study was to develop powder X-ray diffraction (XRPD) chemometric model for quantifying crystalline tacrolimus from solid dispersion (SD). Three SDs (amorphous tacrolimus component) with varying drug to excipient ratios (24.4%, 6.7%, and 4.3% drug) were prepared. Placebo SDs were mixed with crystalline tacrolimus to make their composition equivalent to three SD (crystalline tacrolimus component). These two components were mixed to cover 0%-100% of crystalline drug. Uniformity of the sample mixtures was confirmed by near-infrared chemical imaging. XRPD showed three distinct peaks of crystalline drug at 8.5°, 10.3°, and 11.2° (2?), which were nonoverlapping with the excipients. Principal component regressions (PCR) and partial least square (PLS) regression used in model development showed high R(2) (>0.99) for all the mixtures. Overall, the model showed low root mean square of standard error, standard error, and bias, which was smaller in PLS than PCR-based model. Furthermore, the model performance was evaluated on the formulations with known percentage of crystalline drug. Model-calculated crystalline drug percentage values were close to actual value. Therefore, these studies strongly suggest the application of chemometric-XRPD models as a quality control tool to quantitatively predict the crystalline drug in the formulation. PMID:24585357

  13. NASA Li/CF(x) cell problem analysis: Scanning electron microscopy with energy dispersive x ray spectrometry

    NASA Astrophysics Data System (ADS)

    Baker, John

    1991-05-01

    An analysis was made of Lithium/carbon fluoride cell parts for possible chloride contamination induced by exposure to thionyl chloride (SOCl2); various samples were submitted for analysis. Only a portion of the analysis which has been conducted is covered, herein, namely analysis by scanning electron microscopy with energy dispersive x ray spectrometry (SEM/EDS). A strip of nickel was exposed to SOCl2 vapors to observe variations in surface concentrations of sulfur and chlorine with time. By detecting chlorine one can not infer contamination by SOCl2 only that contamination is present. Six samples of stainless steel foil were analyzed for chlorine using EDS. Chlorine was not detected on background samples but was detected on the samples which had been handled including those which had been cleaned. Cell covers suspected of being contaminated while in storage and covers which were not exposed to the same storage conditions were analyzed for chlorine. Although no chlorine was found on the covers from cells, it was found on all stored covers. Results are presented with techniques shown for analysis and identification. Relevant photomicrographs are presented.

  14. Misfit strain of oxygen precipitates in Czochralski silicon studied with energy-dispersive X-ray diffraction

    SciTech Connect

    Gröschel, A., E-mail: alexander.groeschel@fau.de; Will, J.; Bergmann, C.; Magerl, A. [Crystallography and Structural Physics, University of Erlangen-Nürnberg, Staudtstr. 3, 91058 Erlangen (Germany)

    2014-06-21

    Annealed Czochralski Silicon wafers containing SiO{sub x} precipitates have been studied by high energy X-ray diffraction in a defocused Laue setup using a laboratory tungsten tube. The energy dispersive evaluation of the diffracted Bragg intensity of the 220 reflection within the framework of the statistical dynamical theory yields the static Debye-Waller factor E of the crystal, which gives access to the strain induced by the SiO{sub x} precipitates. The results are correlated with precipitate densities and sizes determined from transmission electron microscopy measurements of equivalent wafers. This allows for the determination of the constrained linear misfit ? between precipitate and crystal lattice. For samples with octahedral precipitates the values ranging from ??=?0.39 (+0.28/?0.12) to ??=?0.48 (+0.34/?0.16) indicate that self-interstitials emitted into the matrix during precipitate growth contribute to the lattice strain. In this case, the expected value calculated from literature values is ??=?0.26?±?0.05. Further, the precise evaluation of Pendellösung oscillations in the diffracted Bragg intensity of as-grown wafers reveals a thermal Debye-Waller parameter for the 220 reflection B{sup 220}(293?K) of 0.5582?±?0.0039 Å{sup 2} for a structure factor based on spherically symmetric scattering contributions.

  15. Atomic-scale Chemical Imaging and Quantification of Metallic Alloy Structures by Energy-Dispersive X-ray Spectroscopy

    NASA Astrophysics Data System (ADS)

    Lu, Ping; Zhou, Lin; Kramer, M. J.; Smith, David J.

    2014-02-01

    Determination of atomic-scale crystal structure for nanostructured intermetallic alloys, such as magnetic alloys containing Al, Ni, Co (alnico) and Fe, is crucial for understanding physical properties such as magnetism, but technically challenging due to the small interatomic distances and the similar atomic numbers. By applying energy-dispersive X-ray spectroscopy (EDS) mapping to the study of two intermetallic phases of an alnico alloy resulting from spinodal decomposition, we have determined atomic-scale chemical composition at individual lattice sites for the two phases: one is the B2 phase with Fe0.76Co0.24 -Fe0.40Co0.60 ordering and the other is the L21 phase with Ni0.48Co0.52 at A-sites, Al at B?-sites and Fe0.20Ti0.80 at B??-sites, respectively. The technique developed through this study represents a powerful real-space approach to investigate structure chemically at the atomic scale for a wide range of materials systems.

  16. Atomic-scale chemical imaging and quantification of metallic alloy structures by energy-dispersive X-ray spectroscopy.

    PubMed

    Lu, Ping; Zhou, Lin; Kramer, M J; Smith, David J

    2014-01-01

    Determination of atomic-scale crystal structure for nanostructured intermetallic alloys, such as magnetic alloys containing Al, Ni, Co (alnico) and Fe, is crucial for understanding physical properties such as magnetism, but technically challenging due to the small interatomic distances and the similar atomic numbers. By applying energy-dispersive X-ray spectroscopy (EDS) mapping to the study of two intermetallic phases of an alnico alloy resulting from spinodal decomposition, we have determined atomic-scale chemical composition at individual lattice sites for the two phases: one is the B2 phase with Fe0.76Co0.24 -Fe0.40Co0.60 ordering and the other is the L2(1) phase with Ni0.48Co0.52 at A-sites, Al at B(?)-sites and Fe0.20Ti0.80 at B(??)-sites, respectively. The technique developed through this study represents a powerful real-space approach to investigate structure chemically at the atomic scale for a wide range of materials systems. PMID:24492747

  17. Atomic-Scale Chemical Imaging and Quantification of Metallic Alloy Structures by Energy-Dispersive X-Ray Spectroscopy

    SciTech Connect

    Lu, Ping [Sandia National Laboratories; Zhou, Lin [Ames Laboratory; Kramer, Matthew J. [Ames Laboratory; Smith, David J. [Arizona State University

    2014-02-04

    Determination of atomic-scale crystal structure for nanostructured intermetallic alloys, such as magnetic alloys containing Al, Ni, Co (alnico) and Fe, is crucial for understanding physical properties such as magnetism, but technically challenging due to the small interatomic distances and the similar atomic numbers. By applying energy-dispersive X-ray spectroscopy (EDS) mapping to the study of two intermetallic phases of an alnico alloy resulting from spinodal decomposition, we have determined atomic-scale chemical composition at individual lattice sites for the two phases: one is the B2 phase with Fe0.76Co0.24 -Fe0.40Co0.60 ordering and the other is the L21 phase with Ni0.48Co0.52 at A-sites, Al at B?-sites and Fe0.20Ti0.80 at B??-sites, respectively. The technique developed through this study represents a powerful real-space approach to investigate structure chemically at the atomic scale for a wide range of materials systems.

  18. Simultaneous nondestructive analysis of palladium, rhodium, platinum, and gold nanoparticles using energy dispersive X-ray fluorescence.

    PubMed

    Fiedler, Haidi D; Drinkel, Emma E; Orzechovicz, Beatriz; Leopoldino, Elder C; Souza, Franciane D; Almerindo, Gizelle I; Perdona, Cristian; Nome, Faruk

    2013-11-01

    A selective method is proposed for the determination of palladium, gold, and sulfur in catalytic systems, by direct liquid analysis using energy dispersive X-ray fluorescence (EDXRF), under an atmosphere of helium or air. This method allows a nondestructive analysis of palladium, rhodium, platinum, and gold nanoparticulate catalysts stabilized by imidazolium propane sulfonate based zwitterionic surfactants, allowing the samples to be reused for catalytic studies. The signals from palladium, rhodium, platinum, and gold samples in the presence of imidazolium propane sulfonate-based zwitterionic surfactants obtained using EDXRF before (Pd(2+), Rh(2+), Pt(2+), and Au(3+)) and after (Pd(0), Rh(0), Pt(0), and Au(0)) formation of nanoparticles are essentially identical. The results show that the EDXRF method is nondestructive and allows detection and quantification of the main components of platinum, gold, rhodium, and palladium NPs, including the surfactant concentration, with detection and quantification limits in the range of 0.4-3 mg L(-1). The matrices used in such samples present no problems, even allowing the detection and quantification of interfering elements. PMID:24090428

  19. Atomic-scale Chemical Imaging and Quantification of Metallic Alloy Structures by Energy-Dispersive X-ray Spectroscopy

    PubMed Central

    Lu, Ping; Zhou, Lin; Kramer, M. J.; Smith, David J.

    2014-01-01

    Determination of atomic-scale crystal structure for nanostructured intermetallic alloys, such as magnetic alloys containing Al, Ni, Co (alnico) and Fe, is crucial for understanding physical properties such as magnetism, but technically challenging due to the small interatomic distances and the similar atomic numbers. By applying energy-dispersive X-ray spectroscopy (EDS) mapping to the study of two intermetallic phases of an alnico alloy resulting from spinodal decomposition, we have determined atomic-scale chemical composition at individual lattice sites for the two phases: one is the B2 phase with Fe0.76Co0.24 -Fe0.40Co0.60 ordering and the other is the L21 phase with Ni0.48Co0.52 at A-sites, Al at B?-sites and Fe0.20Ti0.80 at B??-sites, respectively. The technique developed through this study represents a powerful real-space approach to investigate structure chemically at the atomic scale for a wide range of materials systems. PMID:24492747

  20. Micro energy-dispersive X-ray fluoresence mapping of enamel and dental materials after chemical erosion.

    PubMed

    Soares, Luís Eduardo Silva; de Oliveira, Rodrigo; Nahórny, Sídnei; Santo, Ana Maria do Espírito; Martin, Airton Abrahão

    2012-10-01

    Energy-dispersive X-ray fluorescence was employed to test the hypothesis that beverage consumption or mouthwash utilization will change the chemical properties of dental materials and enamel mineral content. Bovine enamel samples (n = 45) each received two cavity preparations (n = 90), each pair filled with one of three dental materials (R: nanofilled composite resin; GIC: glass-ionomer cement; RMGIC: resin-modified GIC). Furthermore, they were treated with three different solutions (S: saliva; E: erosion/Pepsi Twist®; or EM: erosion+mouthwash/Colgate Plax®). It was found that mineral loss in enamel was greater in GICE samples than in RE > RMGICE > RMGICEM > REM > GICEM. An increased percentage of Zr was found in REM indicating organic matrix degradation. Dental materials tested (R, GIC, and RMGIC) were not able to protect adjacent enamel from acid erosion by the soft drink tested. The use of mouthwash promoted protection of enamel after erosion by the soft drink. To avoid chemical dissolution by mouthwashes, protection by resin composites with surface sealants is recommended. PMID:23095448

  1. Demonstration of saturated tabletop soft x-ray lasers at 5 Hz repetition rate in transitions of Ne-like ions with wavelengths near 30 nm

    NASA Astrophysics Data System (ADS)

    Wang, Yong; Shlyaptsev, Vyacheslav N.; Rocca, Jorge J.

    2005-10-01

    Recent experiments have demonstrated that the laser pump energy required to operate collisional soft x-ray lasers in the gain saturated regime can be significantly reduced by directing the heating pulse into the plasma at grazing incidence for a more efficient energy deposition [1-2]. Optimization of the incidence angle led to gain-saturated operation at 5Hz repetition rate in several transitions of Ni-like ions at wavelengths ranging from 18.9nm to 13.2nm [3]. We report saturated high repetition rate laser-pumped table-top soft x-ray lasers in Ne-like ions at wavelengths near 30nm. Gain-saturated lasers operating at 5Hz repetition rate were obtained in Ne-like Ti at 32.6nm and in Ne-like V at 30.4nm heating plasmas with laser pulses of ˜1J and 8ps impinging at 20^o grazing incidence. Average powers > 1?W were measured. Strong lasing was also observed in Ne-like Cr at 28.6nm. 1. R. Keenan et al, Phys. Rev. Lett., 94, 103901, (2005). 2. B. M. Luther et al, Opt. Lett., 30, 165, (2005). 3. Y. Wang et al, submitted to Phys. Rev. A, (2005).

  2. Soliton trapping of dispersive waves in photonic crystal fiber with two zero dispersive wavelengths.

    PubMed

    Wang, Weibin; Yang, Hua; Tang, Pinghua; Zhao, Chujun; Gao, Jing

    2013-05-01

    Based on the generalized nonlinear Schrödinger equation, we present a numerical study of trapping of dispersive waves by solitons during supercontinuum generation in photonic crystal fibers pumped with femtosecond pulses in the anomalous dispersion region. Numerical simulation results show that the generated supercontinuum is bounded by two branches of dispersive waves, namely blue-shifted dispersive waves (B-DWs) and red-shifted dispersive waves (R-DWs). We find a novel phenomenon that not only B-DWs but also R-DWs can be trapped by solitons across the zero-dispersion wavelength when the group-velocity matching between the soliton and the dispersive wave is satisfied, which may led to the generation of new spectral components via mixing of solitons and dispersive waves. Mixing of solitons with dispersive waves has been shown to play an important role in shaping not only the edge of the supercontinuum, but also its central part around the higher zero-dispersion wavelength. Further, we show that the phenomenon of soliton trapping of dispersive waves in photonic crystal fibers with two zero-dispersion wavelengths has a very close relationship with pumping power and the interval between two zero-dispersion wavelengths. In order to clearly display the evolution of soliton trapping of dispersive waves, the spectrogram of output pulses is observed using cross-correlation frequency-resolved optical gating technique (XFROG). PMID:23669979

  3. A multi-wavelength view of AB Doradus outer atmosphere . Simultaneous X-ray and optical spectroscopy at high cadence

    NASA Astrophysics Data System (ADS)

    Lalitha, S.; Fuhrmeister, B.; Wolter, U.; Schmitt, J. H. M. M.; Engels, D.; Wieringa, M. H.

    2013-12-01

    Aims: We study the chromosphere and corona of the ultra-fast rotator AB Dor A at high temporal and spectral resolution using simultaneous observations with XMM-Newton in the X-rays, VLT/UVES in the optical, and the ATCA in the radio. Our optical spectra have a resolving power of ~50 000 with a time cadence of ~1 min. Our observations continuously cover more than one rotational period and include both quiescent periods and three flaring events of different strengths. Methods: From the X-ray observations we investigated the variations in coronal temperature, emission measure, densities, and abundance. We interpreted our data in terms of a loop model. From the optical data we characterised the flaring chromospheric material using numerous emission lines that appear in the course of the flares. A detailed analysis of the line shapes and line centres allowed us to infer physical characteristics of the flaring chromosphere and to coarsely localise the flare event on the star. Results: We specifically used the optical high-cadence spectra to demonstrate that both turbulent and Stark broadening are present during the first ten minutes of the first flare. Also, in the first few minutes of this flare, we find short-lived (one to several minutes) emission subcomponents in the H? and Ca ii K lines, which we interpret as flare-connected shocks owing to their high intrinsic velocities. Combining the space-based data with the results of our optical spectroscopy, we derive flare-filling factors. Finally, comparing X-ray, optical broadband, and line emission, we find a correlation for two of the three flaring events, while there is no clear correlation for one event. Also, we do not find any correlation of the radio data to any other observed data. Based on observations collected at the European Southern Observatory, Paranal, Chile, 383.D-1002A and on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA member states and NASA.Full Table 6 and reduced data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/560/A69

  4. Broadband Wavelength Spanning Holographic Polymer Dispersed Liquid Crystals

    NASA Astrophysics Data System (ADS)

    Rai, Kashma; Shriyan, Sameet; Fontecchio, Adam

    2008-03-01

    Broadened interaction wavelength of holographic polymer dispersed liquid crystals (HPDLCs) have extensive applications in beam steering for instrument clusters, hyperspectral imaging, wavelength filtering and construction of lightweight optics. A novel simultaneous time and spatial multiplexing formation configuration is proposed here, to increase narrow wavelength reflecting notch to broad range wavelength spanning device. HPDLC films have electro-optic controllability by applying field. No moving parts, light weight, small footprint compared to prisms and lenses, high color purity make the broadband wavelength HPDLCs desirable for the above applications. Varying the incident laser beam exposure angles using motorized rotating stage, during formation is the key step here for their formation in a single medium. The fabricated broadband wavelength sensitive HPDLCs are characterized for the uniformity of the reflected peak and electro optic response. Their output wavefront is analyzed using wavefront analysis technique.

  5. Simulation of an energy-dispersion x-ray spectrometer in the computational medium X-Energo

    SciTech Connect

    Plotnikov, R.I.; Savel`ev, S.K.; Fedorov, S.I. [Baltic State Technical Univ., St. Petersburg (Russian Federation)

    1995-01-01

    The description of the calculation part of the simulation medium X-Energo is presented. It contains mathematical models included in the medium X-Energo for the determinating major processes taking place in an X-ray spectrometer, namely, the formation of an X-ray radiation spectrum, the interaction of this radiation with filter and sample materials, and the detector response to the signal. 6 refs.

  6. Lung dust content in idiopathic pulmonary fibrosis: a study with scanning electron microscopy and energy dispersive x ray analysis.

    PubMed Central

    Monsó, E; Tura, J M; Pujadas, J; Morell, F; Ruiz, J; Morera, J

    1991-01-01

    Examination with an optical microscope and polarised light is not sensitive enough to detect low diameter asbestos fibres. This limitation implies that some cases of asbestosis can be erroneously diagnosed as idiopathic pulmonary fibrosis (IPF) if asbestos bodies are not found in the standard examination of abnormal tissue. To determine whether IPF is over-diagnosed, a study was carried out with scanning electron microscopy (SEM) and energy dispersive x ray analysis (EDXA) on 25 samples previously diagnosed as IPF at the standard examination. Scanning electron microscopy will show the presence of low diameter fibres in the lung without tissue destruction, and these fibres can be identified using EDXA. The quantitative and qualitative results for lung tissue from patients diagnosed as having IPF were compared with the results of the examination of 25 samples of normal lung. Most of the samples from patients diagnosed as having IPF showed only occasional inorganic particles (less than 10 particles/SEM field at 160 x), results equivalent to the results obtained in normal lung. Two cases of IPF, however, showed innumerable asbestos fibres (greater than 100 fibres/SEM field). One of these two patients had an antecedent of brief exposure to asbestos. No environmental antecedent was found in the second patient. Asbestosis was the final diagnosis for these two patients. The examination of inorganic particles in normal lungs showed mainly non-fibrous silicates (61.4%) and particles of heavy elements (34.9%). Only one asbestos fibre was found (0.9%). It is concluded that standard pathological techniques overdiagnose IPF in a few cases in which asbestos bodies are not found with the optical microscope. Images PMID:2039745

  7. High-pressure structural transformations of Sn up to 138 GPa: Angle-dispersive synchrotron x-ray diffraction study

    NASA Astrophysics Data System (ADS)

    Salamat, Ashkan; Briggs, Richard; Bouvier, Pierre; Petitgirard, Sylvain; Dewaele, Agnès; Cutler, Melissa E.; Corà, Furio; Daisenberger, Dominik; Garbarino, Gaston; McMillan, Paul F.

    2013-09-01

    The high-pressure behavior of elemental Sn has been studied by angle-dispersive synchrotron x-ray diffraction up to 138 GPa under quasihydrostatic conditions at room temperature. The data confirm the occurrence of a first-order phase transition at 10.8 GPa between ?-Sn (Sn-II) (I41/amd) and a further body-centered-tetragonal polymorph (?-Sn or Sn-III) (I4/mmm). Above 32 GPa, this phase exhibits a distortion into a new body-centered-orthorhombic (bco) modification (Immm). Beyond 70 GPa, the structure becomes body-centered cubic (bcc) (Im-3m). There is a region of coexistence where the bcc reflections are observed to appear superimposed on the bco pattern above 40 GPa and the two diffraction signatures coexist until 70 GPa. We examined this possible existence of a kinetically hindered first-order phase transition between the two polymorphs by performing density functional theory (DFT) calculations with an emphasis on the potential energy in response to axial (c/a,b/a) distortions at constant volume. The DFT results suggest a slightly different interpretation of the structural transformations. At low pressure, the global minimum energy is always centered around b/a=1, and there is no indication of transformation to a bco structure. However, any small strains in the c/a ratio in the system would provide an orthorhombic distortion of the observed magnitude. Such strains could be induced due to slight deviations from hydrostatic conditions in the experimental study. Concerning the possible bco-bcc phase transitions, the DFT calculations reveal an energy surface with a barrier developed between solutions with different c/a values over the pressure range of interest. Crucially, the calculated barrier heights are low, and they disappear in the region of the observed phase transformation. The DFT results indicate a mechanically softened material that may exhibit localized domain structures in response to even slightly nonhydrostatic stress conditions.

  8. Characterization of the interfacial geomechanics in gas shales via integrated Raman spectroscopy, nanoindentation and energy dispersive X-ray spectroscopy

    NASA Astrophysics Data System (ADS)

    Ferralis, N.; Abedi, S.; Grossman, J. C.; Ulm, F.

    2012-12-01

    The geomechanical characterization of gas shales at the microscale is currently enabled by the use of grid-based nanoindentation techniques. However, the inability to probe the chemical and mineral heterogeneity of gas shales limits the identification of the geomechanical properties of individual components and phases within the probed region. The development of an integrated multiphysics approach that combines geomechanical and chemical information is crucial for the characterization of interfaces between phases, leading to the identification of regions with low yield strain. Here we present a comprehensive investigation where a spatially aligned coupled multiphysics analysis of gas shales is used to identify relevant the geomechanics of mineral and organic phases and their interfaces. This method uses grid-based nanondentation to extract the geomechanical information. Raman spectroscopy is used to identify the majority of inorganic components (calcite, quartz, anatase, pyrite, clay) as well as to characterize the diversity and maturity in the organic component (kerogen). Energy dispersive X-ray is used in combination with Raman to identify clay. With the use of clustering analysis statistical tools a correlation analysis over the full range of data (geomechanics and chemical data), we identify several mineral phases, and we clearly associate the mechanical properties (defined in terms of hardness, modulus and yield strain) with each phase. With this innovative multiphysics analysis we were able to identify interfacial phases between inorganic phases, with distinct hardness and yield strain. We find that regions between calcite-rich or quartz rich phases and clay-rich phases showed a lower than of that of the corresponding boundary phases. Hence this approach provides a viable method for the identification of the "weakest links" in gas shales with the highest probability of fracture.

  9. Energy dispersive X-ray microanalysis, neutron activation analysis and atomic absorption spectrometry--comparison using biological specimens

    SciTech Connect

    Wroblewski, R.; Wroblewski, J.; Lundstroem, H.E.; Edstroem, L.J.; Jansson, E. (St Goeran Hospital, Stockholm (Sweden))

    1989-06-01

    X-ray microanalysis, neutron activation analysis and atomic absorption spectrometry were performed on normal and injured skeletal muscle. X-ray microanalysis of tenotomized rat soleus muscle showed significantly elevated levels of sodium and chlorine and lower potassium compared with normal muscle. Similar ion shifts could be demonstrated by neutron activation analysis and atomic absorption spectrometry. The concentrations of sodium and chlorine obtained by these techniques were somewhat higher and that of potassium lower than the values obtained by X-ray microanalysis. This can probably be attributed to the fact that in atomic absorption spectrometry and in neutron activation analysis the entire muscle biopsy contents are measured while in X-ray microanalysis only the content of muscle cells unaffected by extracellular, non-muscular components are determined. It can be concluded that X-ray microanalysis is a reliable technique to study the elemental content of biological tissue, especially tissue undergoing pathological changes affecting the extracellular spaces. Other types of analysis should be used when elements not detectable by X-ray microanalysis are of interest.

  10. In-situ energy-dispersive X-ray diffraction of metal sulfide assisted crystallization of strongly (001) textured photoactive tungsten disulfide thin films

    Microsoft Academic Search

    S. Brunken; R. Mientus; K. Ellmer

    2009-01-01

    Highly (001) textured tungsten disulphide (WS2) thin films were grown by rapid metal (Ni, Pd) sulfide assisted crystallization of amorphous reactively sputtered sulfur-rich tungsten sulfide (WS3+x) and by metal sulfide assisted sulfurization of tungsten metal films. The rapid crystallization was monitored by real-time in-situ energy dispersive X-ray diffraction (EDXRD). Provided that a thin nickel or palladium film was deposited prior

  11. Non-invasive identification of chemical compounds by energy dispersive X-ray fluorescence spectrometry, combined with chemometric methods of data evaluation

    Microsoft Academic Search

    A. Henrich; P. Hoffmann; H. M. Ortner; T. Greve; H. Itzel

    2000-01-01

    Chemicals from customers’ returns have to be analyzed before they can be reused as raw materials in production. A procedure\\u000a for non-invasive qualitative analysis of compounds in a closed container based on energy dispersive X-ray fluorescence (EDXRF)\\u000a spectrometry is described. EDXRF was chosen as method for non-invasive analysis of chemicals through PE bottle walls without\\u000a opening the bottle. This analysis

  12. The utility of bronchoalveolar lavage and transbronchial lung biopsy combined with energy-dispersive X-ray analysis in the diagnosis of silicosis

    SciTech Connect

    Nugent, K.M.; Dodson, R.F.; Idell, S.; Devillier, J.R. (Univ. of Texas Health Center, Tyler (USA))

    1989-11-01

    We used analytical electron microscopic techniques, including energy-dispersive X-ray analysis, to evaluate a patient with diffuse infiltrates and a history of silica exposure. We identified silica particles in digested bronchoalveolar lavage fluid, sectioned alveolar macrophages recovered by lavage, and parenchymal specimens obtained by transbronchial biopsy. This analysis confirmed our clinical suspicion (a sporadic case of accelerated silicosis) and eliminated the need for additional, more complicated, diagnostic procedures.

  13. A shield for reducing the thermal signal from heating holders during in situ energy-dispersive X-ray spectroscopy analysis.

    PubMed

    Eswaramoorthy, Santhana K; Howe, James M; Phillipp, Fritz

    2007-08-01

    This article describes a simple shield that can be placed on typical commercial heating holders to reduce the thermal signal during heating to reasonable levels for in situ energy-dispersive X-ray spectroscopy analysis. The improved temperature capability provided by the shield is demonstrated by initial compositional analysis results obtained across a solid-liquid interface on Al-Si-Cu-Mg alloy powder particles. Considerations in the design of and improvement for the shield are discussed. PMID:17637078

  14. X-ray imaging and x-ray source development at Lawrence Livermore National Laboratory

    SciTech Connect

    Trebes, J.; Balhorn, R. [Lawrence Livermore National Lab., CA (United States); Anderson, E. [Lawrence Berkeley Lab., CA (United States)] [and others

    1993-12-01

    The Laser Program at Lawrence Livermore National Laboratory has a continuing effort to develop both x-ray sources and x-ray sources and x-ray microscopy. This effort includes the ongoing development of: (1) a wide range of x-ray lasers at the Nova Laser Facility, (2) a zone plate lens--multilayer mirror based x-ray microscope (3) three dimensional, high resolution x-ray microscopy (4) short wavelength, normal incidence multilayer x-ray mirrors, (5) compact, high average power lasers for producing x-ray lasers and laser plasma x-ray sources. We have constructed and operated an x-ray laser based transmission x-ray microscope. The advantage offered by the x-ray laser source is the extreme high brightness allows high resolution images to be made on a timescale faster than that for x-ray damage effects to appear. The microscope, consists of: the x-ray laser, a multilayer coated, near normal incidence spherical mirror used as a condenser, a silicon nitride specimen holder, an x-ray zone plate used as an objective lens, and a microchannel plate x-ray detector. The x-ray laser used is the Ni-like Ta x-ray laser operating with a wavelength of 4.48 nm, a pulselength of 200 spec, a divergence of 10 mrad, and an output energy of 10 microjoules.

  15. MATHEMATICAL TECHNIQUES FOR X-RAY ANALYZERS

    EPA Science Inventory

    Mathematical techniques and subsequent computer software were developed to process energy-dispersive x-ray fluorescence spectra for elemental analysis of airborne particulate matter collected on filters. The research concerned two areas: (1) determination of characteristic x-ray ...

  16. Debris of potassium-magnesium silicate glass generated by femtosecond laser-induced ablation in air: An analysis by near edge X-ray absorption spectroscopy, micro Raman and energy dispersive X-ray spectroscopy

    NASA Astrophysics Data System (ADS)

    Grehn, M.; Seuthe, T.; Reinhardt, F.; Höfner, M.; Griga, N.; Eberstein, M.; Bonse, J.

    2014-05-01

    The redeposited material (debris) resulting from ablation of a potassium-magnesium silicate glass upon scanning femtosecond laser pulse irradiation (130 fs, 800 nm) in air environment is investigated by means of three complementary surface analytical methods. Changes in the electronic band structure of the glass constituent Magnesium (Mg) were identified by X-ray Absorption Near Edge Structure spectroscopy (XANES) using synchrotron radiation. An up-shift of ?0.8 eV of a specific Magnesium K-edge absorption peak in the spectrum of the redeposited material along with a significant change in its leading edge position was detected. In contrast, the surface left after laser ablation exhibits a downshift of the peak position by ?0.9 eV. Both observations may be related to a change of the Mg coordinative state of the laser modified/redeposited glass material. The presence of carbon in the debris is revealed by micro Raman spectroscopy (?-RS) and was confirmed by energy dispersive X-ray spectroscopy (EDX). These observations are attributed to structural changes and chemical reactions taking place during the ablation process.

  17. A new method for polychromatic X-ray ?Laue diffraction on a Cu pillar using an energy-dispersive pn-junction charge-coupled device

    NASA Astrophysics Data System (ADS)

    Abboud, A.; Kirchlechner, C.; Send, S.; Micha, J. S.; Ulrich, O.; Pashniak, N.; Strüder, L.; Keckes, J.; Pietsch, U.

    2014-11-01

    ?Laue diffraction with a polychromatic X-ray beam can be used to measure strain fields and crystal orientations of micro crystals. The hydrostatic strain tensor can be obtained once the energy profile of the reflections is measured. However, this remains a challenge both on the time scale and reproducibility of the beam position on the sample. In this review, we present a new approach to obtain the spatial and energy profiles of Laue spots by using a pn-junction charge-coupled device, an energy-dispersive area detector providing 3D resolution of incident X-rays. The morphology and energetic structure of various Bragg peaks from a single crystalline Cu micro-cantilever used as a test system were simultaneously acquired. The method facilitates the determination of the Laue spots' energy spectra without filtering the white X-ray beam. The synchrotron experiment was performed at the BM32 beamline of ESRF using polychromatic X-rays in the energy range between 5 and 25 keV and a beam size of 0.5 ?m × 0.5 ?m. The feasibility test on the well known system demonstrates the capabilities of the approach and introduces the "3D detector method" as a promising tool for material investigations to separate bending and strain for technical materials.

  18. High-power-density capillary discharge plasma columns for shorter wavelength discharge-pumped soft-x-ray lasers

    E-print Network

    Rocca, Jorge J.

    High-power-density capillary discharge plasma columns for shorter wavelength discharge-pumped soft 4 June 2001; published 24 January 2002 We report the generation of plasma columns in gas-filled capillary channels using discharge excitation powers that exceed those of previous studies by one to two

  19. ENERGY DISPERSIVE X-RAY FLUORESCENCE ANALYSIS OF DUST COLLECTED USING A VERTICAL ELUTRIATOR COTTON DUST SAMPLER

    EPA Science Inventory

    X-ray fluorescence (XRF) spectroscopy has been used to analyze trace element concentrations in cotton dusts collected on verticle elutriator filter media. Twenty-three samples collected from ten bales of cotton processed in a model card room have been analyzed. The major elements...

  20. Center for X-Ray Optics, 1986

    SciTech Connect

    Not Available

    1987-07-01

    The Center for X-Ray Optics has made substantial progress during the past year on the development of very high resolution x-ray technologies, the generation of coherent radiation at x-ray wavelengths, and, based on these new developments, had embarked on several scientific investigations that would not otherwise have been possible. The investigations covered in this report are topics on x-ray sources, x-ray imaging and applications, soft x-ray spectroscopy, synchrotron radiation, advanced light source and magnet structures for undulators and wigglers. (LSP)

  1. High repetition rate tabletop soft x-ray lasers at wavelengths down to 11.9 nm in Nickel-like ions

    NASA Astrophysics Data System (ADS)

    Luther, Bradley M.; Shlyaptsev, Vyacheslav N.; Rocca, Jorge J.

    2005-10-01

    There is significant interest in the development of high average power table-top soft x-ray lasers (SXL) for applications. The repetition rate of gain-saturated collisional SXL operating at wavelengths of less than 30nm has been limited to one shot every several minutes by the large laser pump energy required to heat the plasma. Recent experiments have demonstrated a large pump energy reduction by directing the heating pulse into the plasma at grazing incidence [1-3]. This pumping geometry takes advantage of the refraction of the pump beam in the plasma to deposit a large fraction of its energy into the gain region. Here we report 5Hz repetition rate operation of gain-saturated table-top lasers with 1-2?W average power in transitions of Ni-like ions (Mo, Ru, Pd, Ag and Cd) at wavelengths between 18.9nm and 13.2nm, using a 1J, 8 ps heating pulse from a Ti:Sa laser. Strong amplification was also observed at 11.9 nm in Ni-like Sn. 1. R. Keenan et al, Phys. Rev. Lett., 94, 103901, (2005). 2. B. M. Luther et al, Opt. Lett., 30, 165, (2005). 3. D. Alessi et al, Opt. Express, 13, 2093, (2005).

  2. Student X-Ray Fluorescence Experiments

    ERIC Educational Resources Information Center

    Fetzer, Homer D.; And Others

    1975-01-01

    Describes the experimental arrangement for x-ray analysis of samples which involves the following: the radioisotopic x-ray disk source; a student-built fluorescence chamber; the energy dispersive x-ray detector, linear amplifier and bias supply; and a multichannel pulse height analyzer. (GS)

  3. Chemometric classification of gunshot residues based on energy dispersive X-ray microanalysis and inductively coupled plasma analysis with mass-spectrometric detection

    NASA Astrophysics Data System (ADS)

    Steffen, S.; Otto, M.; Niewoehner, L.; Barth, M.; Bro¿?ek-Mucha, Z.; Biegstraaten, J.; Horváth, R.

    2007-09-01

    A gunshot residue sample that was collected from an object or a suspected person is automatically searched for gunshot residue relevant particles. Particle data (such as size, morphology, position on the sample for manual relocation, etc.) as well as the corresponding X-ray spectra and images are stored. According to these data, particles are classified by the analysis-software into different groups: 'gunshot residue characteristic', 'consistent with gunshot residue' and environmental particles, respectively. Potential gunshot residue particles are manually checked and - if necessary - confirmed by the operating forensic scientist. As there are continuing developments on the ammunition market worldwide, it becomes more and more difficult to assign a detected particle to a particular ammunition brand. As well, the differentiation towards environmental particles similar to gunshot residue is getting more complex. To keep external conditions unchanged, gunshot residue particles were collected using a specially designed shooting device for the test shots revealing defined shooting distances between the weapon's muzzle and the target. The data obtained as X-ray spectra of a number of particles (3000 per ammunition brand) were reduced by Fast Fourier Transformation and subjected to a chemometric evaluation by means of regularized discriminant analysis. In addition to the scanning electron microscopy in combination with energy dispersive X-ray microanalysis results, isotope ratio measurements based on inductively coupled plasma analysis with mass-spectrometric detection were carried out to provide a supplementary feature for an even lower risk of misclassification.

  4. ArtTAX--a new mobile spectrometer for energy-dispersive micro X-ray fluorescence spectrometry on art and archaeological objects.

    PubMed

    Bronk, H; Röhrs, S; Bjeoumikhov, A; Langhoff, N; Schmalz, J; Wedell, R; Gorny, H E; Herold, A; Waldschläger, U

    2001-10-01

    A newly developed spectrometer for energy-dispersive micro X-ray fluorescence spectrometry has been designed for the demands of archaeometry. ArtTAX combines the advantages of non-destructive and sensitive multi-elemental analysis at sub-mm resolution with the possibility of working outside the laboratory. The spectrometer consists of an air-cooled, low-power molybdenum tube, new generation polycapillary X-ray optics, a silicon drift detector without the need for liquid-nitrogen cooling, a CCD camera, and three light diodes for sample positioning. The motor-driven measurement head is fixed on a x,y,z-flexible tripod support which can be assembled and dismantled within minutes. The spot size of the primary X-ray beam was determined to be 94 microm for the Cu(Kalpha) energy, the detection limits are in a range of a few tens of microg g(-1) for the medium energy-range in glass. Additional open helium purging in the excitation and detection paths enables the determination of elements down to sodium, thus avoiding vacuum conditions or a size-limiting sample chamber. A selection of qualitative and quantitative results on pigment, metal, glass, and enamel analyses are presented to show the potential of ArtTAX in the field of art and archaeology. PMID:11688642

  5. RF Single Electron Transistor Readout Amplifiers for Superconducting Astronomical Detectors for X-Ray to Sub-mm Wavelengths

    NASA Technical Reports Server (NTRS)

    Stevenson, Thomas; Aassime, Abdelhanin; Delsing, Per; Frunzio, Luigi; Li, Li-Qun; Prober, Daniel; Schoelkopf, Robert; Segall, Ken; Wilson, Chris; Stahle, Carl

    2000-01-01

    We report progress on using a new type of amplifier, the Radio-Frequency Single-Electron Transistor (RF-SET), to develop multi-channel sensor readout systems for fast and sensitive readout of high impedance cryogenic photodetectors such as Superconducting Tunnel Junctions and Single Quasiparticle Photon Counters. Although cryogenic, these detectors are desirable because of capabilities not other-wise attainable. However, high impedances and low output levels make low-noise, high-speed readouts challenging, and large format arrays would be facilitated by compact, low-power, on-chip integrated amplifiers. Well-suited for this application are RF-SETs, very high performance electrometers which use an rf readout technique to provide 100 MHz bandwidth. Small size, low power, and cryogenic operation allow direct integration with detectors, and using multiple rf carrier frequencies permits simultaneous readout of 20-50 amplifiers with a common electrical connection. We describe both the first 2-channel demonstration of this wavelength division multiplexing technique for RF-SETs, and Charge-Locked-Loop operation with 100 kHz of closed-loop bandwidth.

  6. A correlative approach to segmenting phases and ferrite morphologies in transformation-induced plasticity steel using electron back-scattering diffraction and energy dispersive X-ray spectroscopy.

    PubMed

    Gazder, Azdiar A; Al-Harbi, Fayez; Spanke, Hendrik Th; Mitchell, David R G; Pereloma, Elena V

    2014-12-01

    Using a combination of electron back-scattering diffraction and energy dispersive X-ray spectroscopy data, a segmentation procedure was developed to comprehensively distinguish austenite, martensite, polygonal ferrite, ferrite in granular bainite and bainitic ferrite laths in a thermo-mechanically processed low-Si, high-Al transformation-induced plasticity steel. The efficacy of the ferrite morphologies segmentation procedure was verified by transmission electron microscopy. The variation in carbon content between the ferrite in granular bainite and bainitic ferrite laths was explained on the basis of carbon partitioning during their growth. PMID:25126753

  7. High pressure induced phase transition in sulfur doped indium phosphide: An angular-dispersive X-ray diffraction and Raman study

    Microsoft Academic Search

    Chih-Ming Lin; Hwo-Shuenn Sheu; Min-Hsiung Tsai; Bi-Ru Wu; Sheng-Rui Jian

    2009-01-01

    The high pressure induced phase transitions in sulfur doped indium phosphide (InP:S) at ambient temperature has been investigated using angular-dispersive X-ray diffraction (ADXRD) and Raman scattering under high pressure up to around 44.6 and 37.4 GPa, respectively. In situ ADXRD measurements found that the transition of InP:S to a rock-salt phase began at 10.4 GPa and completed at 13.3 GPa with a 15.7%

  8. Tautomerism in liquid 1,2,3-triazole: a combined Energy-Dispersive X-Ray Diffraction, Molecular Dynamics and FTIR study

    E-print Network

    Bellagamba, Marco; Gontrani, Lorenzo; Guidoni, Leonardo; Sadun, Claudia

    2013-01-01

    In this work, we report a multitechnique (energy-dispersive X-Ray diffraction, computational methods and FT-IR spectroscopy) study of the tautomeric equilibrium of 1,2,3-triazole, one of the few small nitrogen-containing eterocycles liquid at room temperature. The T-2H form (C2v symmetry) is found to be strongly favored in gas and solid phases, whereas the neat liquid gives diffraction patterns that can be interpreted satisfactorily with the structure functions calculated from some molecular dynamics results for both T-2H and T-1H tautomers, although the T-2H form gives a slightly better agreement.

  9. A scanning angle energy-dispersive X-ray diffraction technique for high-pressure structure studies in diamond anvil cells

    SciTech Connect

    Yang, Wenge; Shen, Guoyin; Wang, Yanbin; Mao, Ho-kwang (CIW); (UC)

    2008-10-24

    A scanning angle diffraction technique with an energy-dispersive solid-state detector (SSD) and white synchrotron radiation has been developed for high-pressure structure studies in diamond anvil cells (DACs). This technique is similar to the CAESAR technique [Y. Wang, T. Uchida, R. Von Dreele, M.L. Rivers, N. Nishiyama, K. Funakoshi, A. Nozawa, and H. Kaneko, A new technique for angle-dispersive powder diffraction using an energy-dispersive setup and synchrotron radiation, J. Appl. Cryst. 37 (2004), p. 947] developed for large-volume presses, but extended to DAC applications with high spatial resolution. The main feature of the technique is the well-defined collimation in the beam path to the detector, which improves the signal-to-noise ratio significantly, compared to routine monochromatic angle-dispersive powder diffraction with area detectors. This is particularly useful and essential for low-scattering materials and for amorphous and liquid diffraction/scattering studies using DACs. Data collected from crystalline and amorphous samples in DACs show that a coarse 2{theta} scan (0.1--0.2{sup o} for crystals and 0.5{sup o} for amorphous structure) is sufficient to obtain reasonable diffraction resolution. The scanning angle energy-dispersive X-ray diffraction technique provides angle-dispersive X-ray diffraction (ADXD) data in multiple energies. Such multi-energy ADXD data carry much more information than regular single-energy ADXD, which could provide site-specific atomic structure information for full structure refinement.

  10. Evaluation of a portable x-ray fluorescence survey meter for the quantitative determination of trace metals in welding fumes

    E-print Network

    Fehrenbacher, Mary Catherine

    1984-01-01

    and was suitable for laboratory determinations only. Most of the spectrometers used at this time were wavelength dispersive spectrometers, in which wavelengths of the elements were separated by Bragg diffraction from an analyzing crystal. An x-ray tube...EVALUATION OF A PORTABLE X-RAY FLUORE~ SURVEY METER FOR TIIE QUANTITATIVE DEPERMINATI(gq OF TRACE METALS IN WELDING FIJvtES A THESIS by MARY CATHERINE FEHRENBACHER Submitted to the Graduate College of Texas A%M University in partial...

  11. Structural characterization of the phospholipid stabilizer layer at the solid-liquid interface of dispersed triglyceride nanocrystals with small-angle x-ray and neutron scattering

    NASA Astrophysics Data System (ADS)

    Schmiele, Martin; Schindler, Torben; Unruh, Tobias; Busch, Sebastian; Morhenn, Humphrey; Westermann, Martin; Steiniger, Frank; Radulescu, Aurel; Lindner, Peter; Schweins, Ralf; Boesecke, Peter

    2013-06-01

    Dispersions of crystalline nanoparticles with at least one sufficiently large unit cell dimension can give rise to Bragg reflections in the small-angle scattering range. If the nanocrystals possess only a small number of unit cells along these particular crystallographic directions, the corresponding Bragg reflections will be broadened. In a previous study of phospholipid stabilized dispersions of ?-tripalmitin platelets [Unruh, J. Appl. Crystallogr.JACGAR0021-889810.1107/S0021889807044378 40, 1008 (2007)], the x-ray powder pattern simulation analysis (XPPSA) was developed. The XPPSA method facilitates the interpretation of the rather complicated small-angle x-ray scattering (SAXS) curves of such dispersions of nanocrystals. The XPPSA method yields the distribution function of the platelet thicknesses and facilitates a structural characterization of the phospholipid stabilizer layer at the solid-liquid interface between the nanocrystals and the dispersion medium from the shape of the broadened 001 Bragg reflection. In this contribution an improved and extended version of the XPPSA method is presented. The SAXS and small-angle neutron scattering patterns of dilute phospholipid stabilized tripalmitin dispersions can be reproduced on the basis of a consistent simulation model for the particles and their phospholipid stabilizer layer on an absolute scale. The results indicate a surprisingly flat arrangement of the phospholipid molecules in the stabilizer layer with a total thickness of only 12 Å. The stabilizer layer can be modeled by an inner shell for the fatty acid chains and an outer shell including the head groups and additional water. The experiments support a dense packing of the phospholipid molecules on the nanocrystal surfaces rather than isolated phospholipid domains.

  12. MICROQUASARS AND X-RAY NOVAE

    E-print Network

    Greiner, Jochen

    Part I MICROQUASARS AND X-RAY NOVAE allbook.tex; 15/11/2000; 21:23; p.1 #12; 2 allbook.tex; 15/11/2000; 21:23; p.2 #12; Recent results on X-ray novae and microquasars at radio and infrared wavelengths and infrared wavelengths have provided a sig- ni#12;cant contribution to our knowledge of X-ray novae

  13. Relationship between dislocations and residual stresses in cold-drawn pearlitic steel analyzed by energy-dispersive X-ray diffraction

    SciTech Connect

    Sato, Shigeo, E-mail: s.sato@imr.tohoku.ac.jp [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Wagatsuma, Kazuaki [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Suzuki, Shigeru [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Kumagai, Masayoshi; Imafuku, Muneyuki [Faculty of Engineering, Tokyo City University, Tokyo 158-8557 (Japan); Tashiro, Hitoshi [Gyoda 361-0011 (Japan); Kajiwara, Kentaro [Japan Synchrotron Radiation Research Institute, Sayo 679-5198 (Japan); Shobu, Takahiasa [Japan Atomic Energy Agency, Sayo 679-5184 (Japan)

    2013-09-15

    We analyzed the dislocation distribution of cold-drawn pearlitic-steel wire by using the line-profile analysis based on the energy dispersive X-ray diffraction (EDXD). Although this line-profile analysis requires a high resolution in reciprocal space, the resolution for EDXD is generally poor due to the energy resolution of the detector. Our analysis demonstrated that the resolution in the reciprocal space can be maximized at small scattering angles. Using the line-profile analysis based on the EDXD, the microstructural parameters such as the crystallite size and the dislocation density of the ferrite phase in the pearlitic steel were successfully analyzed. In addition, the distribution of the residual stress of the ferrite phase of a pearlitic steel wire was also analyzed using the EDXD measurement. - Highlights: • Energy dispersive X-ray diffraction is applied to the line-profile analysis. • Distribution of dislocations in ferrite in the pearlitic steel wire is analyzed. • Relationship between dislocations and residual stress is discussed.

  14. Nondestructive characterization of municipal-solid-waste-contaminated surface soil by energy-dispersive X-ray fluorescence and low-Z (atomic number) particle electron probe X-ray microanalysis.

    PubMed

    Gupta, Dhrubajyoti; Ghosh, Rita; Mitra, Ajoy K; Roy, Subinit; Sarkar, Manoranjan; Chowdhury, Subhajit; Bhowmik, Asit; Mukhopadhyay, Ujjal; Maskey, Shila; Ro, Chul-Un

    2011-11-01

    The long-term environmental impact of municipal solid waste (MSW) landfilling is still under investigation due to the lack of detailed characterization studies. A MSW landfill site, popularly known as Dhapa, in the eastern fringe of the metropolis of Kolkata, India, is the subject of present study. A vast area of Dhapa, adjoining the current core MSW dump site and evolving from the raw MSW dumping in the past, is presently used for the cultivation of vegetables. The inorganic chemical characteristics of the MSW-contaminated Dhapa surface soil (covering a 2-km stretch of the area) along with a natural composite (geogenic) soil sample (from a small countryside farm), for comparison, were investigated using two complementary nondestructive analytical techniques, energy-dispersive X-ray fluorescence (EDXRF) for bulk analysis and low-Z (atomic number) particle electron probe X-ray microanalysis (low-Z particle EPMA) for single-particle analysis. The bulk concentrations of K, Rb, and Zr remain almost unchanged in all the soil samples. The Dhapa soil is found to be polluted with heavy metals such as Cu, Zn, and Pb (highly elevated) and Ti, Cr, Mn, Fe, Ni, and Sr (moderately elevated), compared to the natural countryside soil. These high bulk concentration levels of heavy metals were compared with the Ecological Soil Screening Levels for these elements (U.S. Environment Protection Agency) to assess the potential risk on the immediate biotic environment. Low-Z particle EPMA results showed that the aluminosilicate-containing particles were the most abundant, followed by SiO2, CaCO3-containing, and carbonaceous particles in the Dhapa samples, whereas in the countryside sample only aluminosilicate-containing and SiO2 particles were observed. The mineral particles encountered in the countryside sample are solely of geogenic origin, whereas those from the Dhapa samples seem to have evolved from a mixture of raw dumped MSW, urban dust, and other contributing factors such as wind, precipitation, weather patterns, farming, and water logging, resulting in their diverse chemical compositions and the abundant observation of carbonaceous species. Particles containing C and P were more abundant in the Dhapa samples than in the countryside soil sample, suggesting that MSW-contaminated soils are more fertile. However, the levels of particles containing potentially toxic heavy metals such as Cr, Mn, Ni, Cu, Zn, and/or Pb in the Dhapa samples were significant, corroborated by their high bulk concentration levels (EDXRF), causing deep concern for the immediate environment and contamination of the food chain through food crops. PMID:22168094

  15. Synchrotron Radiation and Energy Dispersive X-Ray Fluorescence Applications on Elemental Distribution in Human Hair and Bones

    SciTech Connect

    Carvalho, M.L.; Marques, A.F.; Brito, J. [Centro de Fisica Atomica, Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisbon (Portugal)

    2003-01-24

    This work is an application of synchrotron microprobe X- Ray fluorescence in order to study elemental distribution along human hair samples of contemporary citizens. Furthermore, X-Ray fluorescence spectrometry is also used to analyse human bones of different historical periods: Neolithic and contemporary subjects. The elemental content in the bones allowed us to conclude about environmental contamination, dietary habits and health status influence in the corresponding citizens. All samples were collected post-mortem. Quantitative analysis was performed for Mn, Fe, Co, Ni, Cu, Zn, Br, Rb, Sr and Pb. Mn and Fe concentration were much higher in bones from pre-historic periods. On the contrary, Pb bone concentrations of contemporary subjects are much higher than in pre-historical ones, reaching 100 {mu}g g-1, in some cases. Very low concentrations for Co, Ni, Br and Rb were found in all the analysed samples. Cu concentrations, allows to distinguish Chalcolithic bones from the Neolithic ones. The distribution of trace elements along human hair was studied for Pb and the obtained pattern was consistent with the theoretical model, based on the diffusion of this element from the root and along the hair. Therefore, the higher concentrations in hair for Pb of contemporary individuals were also observed in the bones of citizens of the same sampling sites. All samples were analysed directly without any chemical treatment.

  16. Structure determination by multiple-wavelength anomalous dispersion (MAD) at the Pr?LIII edge.

    PubMed

    Puehringer, Sandra; Hellmig, Michael; Liu, Sunbin; Weiss, Manfred S; Wahl, Markus C; Mueller, Uwe

    2012-08-01

    The use of longer X-ray wavelengths in macromolecular crystallography has grown significantly over the past few years. The main reason for this increased use of longer wavelengths has been to utilize the anomalous signal from sulfur, providing a means for the experimental phasing of native proteins. Here, another possible application of longer X-ray wavelengths is presented: MAD at the L(III) edges of various lanthanide compounds. A first experiment at the L(III) edge of Pr was conducted on HZB MX beamline BL14.2 and resulted in the successful structure determination of the C-terminal domain of a spliceosomal protein. This experiment demonstrates that L(III) edges of lanthanides constitute potentially attractive targets for long-wavelength MAD experiments. PMID:22869138

  17. Structure determination by multiple-wavelength anomalous dispersion (MAD) at the Pr?L III edge

    PubMed Central

    Puehringer, Sandra; Hellmig, Michael; Liu, Sunbin; Weiss, Manfred S.; Wahl, Markus C.; Mueller, Uwe

    2012-01-01

    The use of longer X-ray wavelengths in macromolecular crystallography has grown significantly over the past few years. The main reason for this increased use of longer wavelengths has been to utilize the anomalous signal from sulfur, providing a means for the experimental phasing of native proteins. Here, another possible application of longer X-ray wavelengths is presented: MAD at the L III edges of various lanthanide compounds. A first experiment at the L III edge of Pr was conducted on HZB MX beamline BL14.2 and resulted in the successful structure determination of the C-terminal domain of a spliceosomal protein. This experiment demonstrates that L III edges of lanthanides constitute potentially attractive targets for long-wavelength MAD experiments. PMID:22869138

  18. Systematics of K and L x-ray production by 6 to 15 MeV/u heavy ion bombardment

    NASA Astrophysics Data System (ADS)

    Blackadar, John Martin, Jr.

    1999-12-01

    The dependence of Cu (target atom) K-shell vacancy production cross sections on projectile atomic number was investigated. A combination of energy and wavelength dispersive x-ray spectrometry was used to measure Cu K x- ray production cross sections and to determine the appropriate fluorescence yields for converting them to vacancy production cross sections. The wavelength dispersive spectra revealed the presence of sizable contributions from predominately single-ionization mechanisms not directly associated with the ion-atom interactions. The cross sections for Z1 > 24 fall far below a Z12 scaling law and are greatly overestimated by the ECPSSR theory. Wavelength dispersive spectrometry was also used to explore the target atomic number, projectile atomic number and projectile velocity dependence of L x-ray structure. Measurements of the angular dependence of the emitted spectra revealed no alignment of the L subshells in these multiply ionized atoms. Dirac-Fock calculations of x-ray energies were performed and a parabolic interpolation procedure was developed to determine the expected energies of the x-ray satellites. A semi- empirical model was developed to predict the numbers of electronic vacancies created in the collision. The results of the wavelength dispersive measurements of both K and L x-rays from solid targets revealed an unexpected saturation in the number of vacancies produced in a single collision at just over 1/2 of the available electrons in the L and M shells, respectively.

  19. High pressure and high temperature investigations on intermetallic compounds using energy-dispersive X-ray powder diffraction

    NASA Astrophysics Data System (ADS)

    Peun, T.; Lauterjung, J.; Hinze, E.

    1995-05-01

    The intermetallic compounds Mg2Si, MoSi2, WSi2, CrSi2, NbSi2, Ti5Si3, TiSi2, ZrSi2 and Al3Nb were investigated in a pressure range up to 70 kbar and a temperature range up to 1500°C in order to determine previously unknown elastic constants and possible phase transformations. The experiments were carried out using the multi-anvil-X-ray apparatus MAX-80 and synchrotron radiation at HASYLAB. A complete phase transition of cubic Mg2Si to a hexagonal phase was observed at 70 kbar and 450°C. The high-pressure/high-temperature phase was quenched and recovered for further investigations. All the other compounds remained stable in the mentioned pressure and temperature range. The bulk moduli covered the range from 436 (10) (Mg2Si) to 3350 (190) (WSi2) kbar.

  20. THE STRUCTURE OF THE ACCRETION DISK IN THE ACCRETION DISK CORONA X-RAY BINARY 4U 1822-371 AT OPTICAL AND ULTRAVIOLET WAVELENGTHS

    SciTech Connect

    Bayless, Amanda J.; Robinson, Edward L.; Cornell, Mark E. [Department of Astronomy, University of Texas at Austin, 1 University Station, Austin, TX 78712-0259 (United States); Hynes, Robert I. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Ashcraft, Teresa A. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-1404 (United States)

    2010-01-20

    The eclipsing low-mass X-ray binary 4U 1822-371 is the prototypical accretion disk corona (ADC) system. We have obtained new time-resolved UV spectroscopy of 4U 1822-371 with the Advanced Camera for Surveys/Solar Blind Channel on the Hubble Space Telescope and new V- and J-band photometry with the 1.3 m SMARTS telescope at Cerro Tololo Inter-American Observatory. We use the new data to construct its UV/optical spectral energy distribution and its orbital light curve in the UV, V, and J bands. We derive an improved ephemeris for the optical eclipses and confirm that the orbital period is changing rapidly, indicating extremely high rates of mass flow in the system, and we show that the accretion disk in the system has a strong wind with projected velocities up to 4000 km s{sup -1}. We show that the disk has a vertically extended, optically thick component at optical wavelengths. This component extends almost to the edge of the disk and has a height equal to approx0.5 of the disk radius. As it has a low brightness temperature, we identify it as the optically thick base of a disk wind, not as the optical counterpart of the ADC. Like previous models of 4U 1822-371, ours needs a tall obscuring wall near the edge of the accretion disk, but we interpret the wall as a layer of cooler material at the base of the disk wind, not as a tall, luminous disk rim.

  1. Tokamak x ray diagnostic instrumentation

    SciTech Connect

    Hill, K.W.; Beiersdorfer, P.; Bitter, M.; Fredrickson, E.; Von Goeler, S.; Hsuan, H.; Johnson, L.C.; Liew, S.L.; McGuire, K.; Pare, V.

    1987-01-01

    Three classes of x-ray diagnostic instruments enable measurement of a variety of tokamak physics parameters from different features of the x-ray emission spectrum. (1) The soft x-ray (1 to 50 keV) pulse-height-analysis (PHA) diagnostic measures impurity concentrations from characteristic line intensities and the continuum enhancement, and measures the electron temperature from the continuum slope. (2) The Bragg x-ray crystal spectrometer (XCS) measures the ion temperature and neutral-beam-induced toroidal rotation velocity from the Doppler broadening and wavelength shift, respectively, of spectral lines of medium-Z impurity ions. Impurity charge state distributions, precise wavelengths, and inner-shell excitation and recombination rates can also be studied. X rays are diffracted and focused by a bent crystal onto a position-sensitive detector. The spectral resolving power E/..delta..E is greater than 10/sup 4/ and time resolution is 10 ms. (3) The x-ray imaging system (XIS) measures the spatial structure of rapid fluctuations (0.1 to 100 kHZ) providing information on MHD phenomena, impurity transport rates, toroidal rotation velocity, plasma position, and the electron temperature profile. It uses an array of silicon surface-barrier diodes which view different chords of the plasma through a common slot aperture and operate in current (as opposed to counting) mode. The effectiveness of shields to protect detectors from fusion-neutron radiation effects has been studied both theoretically and experimentally.

  2. A standards-based method for compositional analysis by energy dispersive X-ray spectrometry using multivariate statistical analysis: application to multicomponent alloys.

    PubMed

    Rathi, Monika; Ahrenkiel, S P; Carapella, J J; Wanlass, M W

    2013-02-01

    Given an unknown multicomponent alloy, and a set of standard compounds or alloys of known composition, can one improve upon popular standards-based methods for energy dispersive X-ray (EDX) spectrometry to quantify the elemental composition of the unknown specimen? A method is presented here for determining elemental composition of alloys using transmission electron microscopy-based EDX with appropriate standards. The method begins with a discrete set of related reference standards of known composition, applies multivariate statistical analysis to those spectra, and evaluates the compositions with a linear matrix algebra method to relate the spectra to elemental composition. By using associated standards, only limited assumptions about the physical origins of the EDX spectra are needed. Spectral absorption corrections can be performed by providing an estimate of the foil thickness of one or more reference standards. The technique was applied to III-V multicomponent alloy thin films: composition and foil thickness were determined for various III-V alloys. The results were then validated by comparing with X-ray diffraction and photoluminescence analysis, demonstrating accuracy of approximately 1% in atomic fraction. PMID:23298470

  3. Iron speciation of airborne subway particles by the combined use of energy dispersive electron probe X-ray microanalysis and Raman microspectrometry.

    PubMed

    Eom, Hyo-Jin; Jung, Hae-Jin; Sobanska, Sophie; Chung, Sang-Gwi; Son, Youn-Suk; Kim, Jo-Chun; Sunwoo, Young; Ro, Chul-Un

    2013-11-01

    Quantitative energy-dispersive electron probe X-ray microanalysis (ED-EPMA), known as low-Z particle EPMA, and Raman microspectrometry (RMS) were applied in combination for an analysis of the iron species in airborne PM10 particles collected in underground subway tunnels. Iron species have been reported to be a major chemical species in underground subway particles generated mainly from mechanical wear and friction processes. In particular, iron-containing particles in subway tunnels are expected to be generated with minimal outdoor influence on the particle composition. Because iron-containing particles have different toxicity and magnetic properties depending on their oxidation states, it is important to determine the iron species of underground subway particles in the context of both indoor public health and control measures. A recently developed analytical methodology, i.e., the combined use of low-Z particle EPMA and RMS, was used to identify the chemical species of the same individual subway particles on a single particle basis, and the bulk iron compositions of airborne subway particles were also analyzed by X-ray diffraction. The majority of airborne subway particles collected in the underground tunnels were found to be magnetite, hematite, and iron metal. All the particles collected in the tunnels of underground subway stations were attracted to permanent magnets due mainly to the almost ubiquitous ferrimagnetic magnetite, indicating that airborne subway particles can be removed using magnets as a control measure. PMID:24069900

  4. X-ray lithography using holographic images

    DOEpatents

    Howells, Malcolm R. (Berkeley, CA); Jacobsen, Chris (Sound Beach, NY)

    1995-01-01

    A non-contact X-ray projection lithography method for producing a desired X-ray image on a selected surface of an X-ray-sensitive material, such as photoresist material on a wafer, the desired X-ray image having image minimum linewidths as small as 0.063 .mu.m, or even smaller. A hologram and its position are determined that will produce the desired image on the selected surface when the hologram is irradiated with X-rays from a suitably monochromatic X-ray source of a selected wavelength .lambda.. On-axis X-ray transmission through, or off-axis X-ray reflection from, a hologram may be used here, with very different requirements for monochromaticity, flux and brightness of the X-ray source. For reasonable penetration of photoresist materials by X-rays produced by the X-ray source, the wavelength X, is preferably chosen to be no more than 13.5 nm in one embodiment and more preferably is chosen in the range 1-5 nm in the other embodiment. A lower limit on linewidth is set by the linewidth of available microstructure writing devices, such as an electron beam.

  5. MULTI-EPOCH MULTI-WAVELENGTH STUDY OF AN ULTRALUMINOUS X-RAY SOURCE IN M101: THE NATURE OF THE SECONDARY

    SciTech Connect

    Liu Jifeng

    2009-10-20

    Ultraluminous X-ray sources are non-nuclear point sources in external galaxies with L{sub X} = 2 x 10{sup 39}-10{sup 41} erg s{sup -1}, and thus are possibly stellar black holes with special radiation mechanisms or intermediate mass black holes of 100-10{sup 5} M {sub sun}. To measure their dynamical mass, one needs to identify the secondary in the optical followed by photometric and spectroscopic monitoring. The counterpart light is usually contaminated, sometimes even dominated, by the X-ray irradiated accretion disk, which complicates the derivation of the properties of the secondary itself. Here, we report a study on M101-ULX1 with 26 Hubble Space Telescope (HST) observations and 33 X-ray observations over 16 years. There were three multi-band HST observations at different optical states over eight years, the spectral energy distributions (SEDs) of which cannot be fitted by the previously claimed secondary of a B supergiant or any other single star. All SEDs can be decomposed into the same stellar component plus a second component due to X-ray irradiation with different contributions at different optical states. The secondary in ULX1 is most likely a WR star as revealed by the SED decompositions and confirmed by the presence of He II lambda4686 emission in the counterpart spectrum. Five X-ray outbursts and two optical peaks are revealed from X-ray and optical light curves, and optical peaks are identified as the optical response to X-ray outbursts. The correlated optical and X-ray variability analysis is suggestive of ellipsoidal modulation with a half-amplitude of 0.05 mag and a period in the range of 1.5-4.5 days. Future photometric and spectroscopic observations are required to confirm the orbital period and measure the dynamical mass for ULX1.

  6. SMM x ray polychromator

    NASA Technical Reports Server (NTRS)

    Saba, J. L. R.

    1993-01-01

    The objective of the X-ray Polychromator (XRP) experiment was to study the physical properties of solar flare plasma and its relation to the parent active region to understand better the flare mechanism and related solar activity. Observations were made to determine the temperature, density, and dynamic structure of the pre-flare and flare plasma as a function of wavelength, space and time, the extent to which the flare plasma departs from thermal equilibrium, and the variation of this departure with time. The experiment also determines the temperature and density structure of active regions and flare-induced changes in the regions.

  7. Cosmic x ray physics

    NASA Technical Reports Server (NTRS)

    Mccammon, Dan; Cox, D. P.; Kraushaar, W. L.; Sanders, W. T.

    1991-01-01

    The annual progress report on Cosmic X Ray Physics for the period 1 Jan. to 31 Dec. 1990 is presented. Topics studied include: soft x ray background, new sounding rocket payload: x ray calorimeter, and theoretical studies.

  8. Chemical speciation of chlorine in particulate matter by wavelength-dispersive PIXE technique

    NASA Astrophysics Data System (ADS)

    Wonglee, Sarinrat; Tada, Tsutomu; Fukuda, Hitoshi; Hasegawa, Jun; Oguri, Yoshiyuki

    2011-12-01

    Chemical speciation of chlorine (Cl) in atmospheric particulate matter (APM) was performed by using a wavelength-dispersive PIXE spectrograph based on high-resolution measurement of Cl-K? emission. Samples of atmospheric particles were size-fractioned and collected by a cascade impactor at an urban area in Tokyo. The target position with respect to the spectrograph was precisely adjusted by a 2D laser displacement sensor to achieve high detection efficiency. The samples were irradiated with 2 MeV protons from a tandem electrostatic accelerator. The beam current was 300-500 nA. During the irradiation, the target was cooled by liquid nitrogen to avoid the evaporation of volatile Cl compounds. The measured spectra for the NaCl standard samples clearly showed the Cl-K? series composed of the K? 1 and the satellite K? x, K? 5 lines. From the measured X-ray yields, it was found that the chemical speciation of samples with Cl concentrations as low as ?1% is possible by this method. The Cl-K? series were also successfully observed in the case of APM samples with particle sizes of 11.0-2.1 ?m. The spectra shapes of the NaCl standard samples and an APM sample were slightly different from each other, because of some possible mixing of non-sea salt component in the APM sample.

  9. Rapid crystallization of WS2 films assisted by a thin nickel layer: An in situ energy-dispersive X-ray diffraction study

    NASA Astrophysics Data System (ADS)

    Ellmer, K.; Seeger, S.; Mientus, R.

    2006-08-01

    By rapid thermal crystallization of an amorphous WS3+x film, deposited by reactive magnetron sputtering at temperatures below 150 °C, layer-type semiconducting tungsten disulfide films (WS2) were grown. The rapid crystallization was monitored in real-time by in situ energy-dispersive X-ray diffraction. The films crystallize very fast (>40 nm/s), provided that a thin nickel film acts as nucleation seeds. Experiments on different substrates and the onset of the crystallization only at a temperature between 600 and 700 °C points to the decisive role of seeds for the textured growth of WS2, most probably liquid NiSx drops. The rapidly crystallized WS2 films exhibit a pronounced (001) texture with the van der Waals planes oriented parallel to the surface, leading to photoactive layers with a high hole mobility of about 80 cm2/Vs making such films suitable as absorbers for thin film solar cells.

  10. Determination of heavy metals in suspended waste water collected from Oued El Harrach Algiers River by Energy Dispersive X-Ray Fluorescence

    NASA Astrophysics Data System (ADS)

    Ouziane, S.; Amokrane, A.; Toumert, I.

    2013-12-01

    A preliminary study of the atmospheric pollution in the centre of Algiers is one of the important fields of applications in the environmental science. Nowadays, we need to evaluate the level of the contamination which has an unfavourable effect on physicochemical properties of soils and plants and namely also on human health. In the present work, water samples collected from Oued El-Harrach Algiers River, have been filtered in 0.45 ?m Millipore filters to be analysed by Energy Dispersive X-Ray Fluorescence technique using 109Cd radioisotope source. Concentrations of the toxic elements like heavy metals are determined and compared with the published ones values by Yoshida [1] and those obtained using PIXE and NAA techniques [6].

  11. Liver concentrations of copper, zinc, iron and molybdenum in sheep and goats from northern Greece, determined by energy-dispersive x-ray fluorescence spectrometry.

    PubMed

    Papachristodoulou, Christina; Stamoulis, Konstantinos; Tsakos, Panagiotis; Vougidou, Christina; Vozikis, Vasileios; Papadopoulou, Chrissanthy; Ioannides, Konstantinos

    2015-04-01

    Energy-dispersive X-Ray fluorescence spectrometry was used to determine the concentrations of copper (Cu), zinc, iron and molybdenum in the liver of 76 sheep and goats from the regions of Macedonia-Thrace, northern Greece. In general, metal concentrations were in the adequate range, with one main exception of Cu-deficiency observed in all of the examined goat liver samples and Cu-toxicity found in 4 % of the sheep liver samples. One-way analysis of variance was carried out to determine significant differences among means depending on animal species, sex and age. Pearson correlation analysis was used to explore correlations between metal concentrations. The results obtained in the present study are discussed in the framework of diagnostic ranges, suggested for classifying the metal status of sheep and goats, and are compared with liver metal concentrations reported world-wide. PMID:25694162

  12. Analysis of Catalonian silver coins from the Spanish War of Independence period (1808-1814) by Energy Dispersive X-ray Fluorescence

    NASA Astrophysics Data System (ADS)

    Pitarch, A.; Queralt, I.; Alvarez-Perez, A.

    2011-02-01

    Between the years 1808 and 1814, the Spanish War of Independence took place. This period, locally known as "Guerra del Francès", generated the need for money and consequently five mints were opened around the Catalan territory. To mark the 200th anniversary of the beginning of the war, an extensive campaign of Energy Dispersive X-ray Fluorescence measurements of some of these "emergency coins" was carried out. Apart from the silver (major constituent of all the studied coins) it has been possible to recognize copper as main metal alloying element. Likewise, the presence of zinc, tin, lead, gold, platinum, antimony, nickel and iron has been also identified. The obtained results have been useful not only for the characterization of the alloys, but also to determine the differences and analogies between the emissions and for historical explanations.

  13. Characterization of municipal solid waste incineration (MSWI) bottom ash by scanning electron microscopy and quantitative energy dispersive X-ray microanalysis (SEM/EDX).

    PubMed

    Speiser, C; Baumann, T; Niessner, R

    2001-07-01

    Scanning electron microscopy (SEM) with energy-dispersive X-ray microanalysis (EDX) is frequently used for morphological and qualitative chemical characterization of different materials. The applicability of this method for phase identification, is, however, often underestimated. The application of SEM/EDX for the characterization of different phases in fresh and altered municipal-waste incinerator bottom-ash samples with high lateral resolution is presented. Polished thin sections were prepared from the samples, but fresh fracture surfaces were also used. The EDX analyses were performed by using the correction procedures of a conventional standardless ZAF correction, a peak-to-background ZAF correction, and a correction method for light-element analysis. Because of their highly reactive properties the bottom-ash SEM samples require a special method of preparation. The method facilitates nondestructive preparation of the sensitive bottom-ash alteration phases (e.g. cement phases, hydroxides, salts) and their microstructures. PMID:11508465

  14. Atomic-Resolution X-ray Energy-Dispersive Spectroscopy Chemical Mapping of Substitutional Dy Atoms in a High-Coercivity Neodymium Magnet

    NASA Astrophysics Data System (ADS)

    Itakura, Masaru; Watanabe, Natsuki; Nishida, Minoru; Daio, Takeshi; Matsumura, Syo

    2013-05-01

    We have investigated local element distributions in a Dy-doped Nd2Fe14B hot-deformed magnet by atomic-column resolution chemical mapping using an X-ray energy-dispersive spectrometer (XEDS) attached to an aberration-corrected scanning transmission electron microscope (Cs-corrected STEM). The positions of the Nd and Dy atomic columns were visualized in the XEDS maps. The substitution of Dy was limited to a surface layer 2-3 unit cells thick in the Nd2Fe14B grains, and the Dy atoms preferentially occupied the 4f-Nd sites of Nd2Fe14B. These results provide further insights into the principal mechanism governing the coercivity enhancement due to Dy doping.

  15. Structural phase transition of ternary dielectric SmGdO3: Evidence from angle dispersive x-ray diffraction and Raman spectroscopic studies

    NASA Astrophysics Data System (ADS)

    Sharma, Yogesh; Sahoo, Satyaprakash; Mishra, A. K.; Misra, Pankaj; Pavunny, Shojan P.; Dwivedi, Abhilash; Sharma, S. M.; Katiyar, Ram S.

    2015-03-01

    High-pressure synchrotron based angle dispersive x-ray diffraction (ADXRD) studies were carried out on SmGdO3 (SGO) up to 25.7 GPa at room temperature. ADXRD results indicated a reversible pressure-induced phase transition from ambient monoclinic to hexagonal phase at ˜8.9 GPa. The observed pressure-volume data were fitted with the third order Birch-Murnaghan equation of state yielding zero pressure bulk modulus B0 = 132(22) and 177(9) GPa for monoclinic (B-type) and hexagonal (A-type) phases, respectively. Pressure dependent micro-Raman spectroscopy further confirmed the monoclinic to hexagonal phase transition at about 5.24 GPa. The mode Grüneisen parameters and pressure coefficients for different Raman modes corresponding to each individual phases of SGO were calculated using pressure dependent Raman mode analysis.

  16. Simultaneous determination of trace elements in lavage fluids from human bronchial alveoli by energy-dispersive x-ray fluorescence. 3. Routine analysis

    SciTech Connect

    Maier, E.A.; Dietemann-Molard, A.; Rastegar, F.; Heimburger, R.; Ruch, C.; Maier, A.; Roegel, E.; Leroy, M.J.

    1987-12-01

    We applied the energy-dispersive x-ray fluorescence technique to determination of trace elements in human bronchoalveolar lavage fluids. Our analysis of more than 200 samples allowed us to determine normal reference values, to be used in characterizing occupational exposure. These values are expressed both in nanograms per 1000 cells (of all kinds) and nanograms per 1000 macrophages to correlate lavage efficiency and dust content of the alveoli. The result expressed in milligrams per liter is not sufficient, because some healthy volunteers showed high concentrations of iron but normal values when expressed vs the number of cells. Some examples of abnormal compositions of broncho-alveolar lavages are reported and the fully automated spectrometer developed for clinical and biological investigations is described.

  17. Thickness measurement of semiconductor thin films by energy dispersive X-ray fluorescence benchtop instrumentation: Application to GaN epilayers grown by molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Queralt, I.; Ibañez, J.; Marguí, E.; Pujol, J.

    2010-07-01

    The importance of thin films in modern high technology products, such as semiconductors, requires fast and non-destructive analysis. A methodology to determine the thickness of single layers with benchtop energy dispersive X-ray fluorescence (EDXRF) instrumentation is described and tested following analytical validation criteria. The experimental work was carried out on gallium nitride thin films epitaxially grown on sapphire substrate. The results of samples with layers in the range from 400 to 1000 nm exhibit a good correlation with the layer thickness determined by optical reflectance. Spectral data obtained using thin layered samples indicate the possibility to precisely evaluate layer thickness from 5 nm, with a low relative standard deviation (RSD < 2%) of the results. In view of the limits of optical reflectance for very thin layer determination, EDXRF analysis offers the potential for the thickness determination of such kind of samples.

  18. Spatially resolved energy dispersive x-ray spectroscopic method for in-situ evaluation of mechanical properties during the growth of a C - Pt composite nanowire

    SciTech Connect

    Banerjee, Amit; Banerjee, S. S., E-mail: satyajit@iitk.ac.in [Department of Physics, Indian Institute of Technology Kanpur, Kanpur, 208016 (India)

    2014-05-15

    A core-shell type C-Pt composite nanowire is fabricated using focused ion and electron beam induced chemical vapor deposition techniques. Using information from spatially resolved energy dispersive x-ray spectra, we detect the resonance vibration in the C-Pt composite nanowire. We use this method to measure the Young's moduli of the constituents (C, Pt) of the composite nanowire and also estimate the density of the FEB CVD grown Pt shell surrounding the C core. By measuring the resonance characteristics of the composite nanowire we estimate a Pt shell growth rate of ?0.9 nms{sup ?1}. The study is analyzed to suggest that the Pt shell growth mechanism is primarily governed by the sticking coefficient of the organometallic vapor on the C nanowire core.

  19. A false report of product tampering involving a rodent and soft drink can: light microscopy, image analysis and scanning electron microscopy/energy dispersive X-ray analysis.

    PubMed

    Platek, F; Ranieri, N; Wolnik, K A

    1997-11-01

    The "Pepsi Tamperings" of 1993 resulted in a large number of cases involving foreign objects reportedly found inside canned soft drinks. Although the majority of cases involved medical syringes and metallic objects, one case involved the report of a mouse found inside a can of Caffeine-Free Diet Pepsi. Using light and polarized light microscopy and computer-assisted image analysis, trace evidence and tooth structure from the suspect mouse were matched to scratches and indentions on the suspect can. Scanning electron microscopy and energy dispersive X-ray analysis were used to compare and match particles of gnawed metal from the lid of the suspect can to other particles recovered from the muzzle and stomach of the suspect mouse. The forensic analyses in this case proved the mouse could not have been canned in the soft drink product and refuted the defendant's sworn statements. PMID:9397564

  20. Spatially resolved energy dispersive x-ray spectroscopic method for in-situ evaluation of mechanical properties during the growth of a C - Pt composite nanowire

    NASA Astrophysics Data System (ADS)

    Banerjee, Amit; Banerjee, S. S.

    2014-05-01

    A core-shell type C-Pt composite nanowire is fabricated using focused ion and electron beam induced chemical vapor deposition techniques. Using information from spatially resolved energy dispersive x-ray spectra, we detect the resonance vibration in the C-Pt composite nanowire. We use this method to measure the Young's moduli of the constituents (C, Pt) of the composite nanowire and also estimate the density of the FEB CVD grown Pt shell surrounding the C core. By measuring the resonance characteristics of the composite nanowire we estimate a Pt shell growth rate of ˜0.9 nms-1. The study is analyzed to suggest that the Pt shell growth mechanism is primarily governed by the sticking coefficient of the organometallic vapor on the C nanowire core.

  1. Simultaneous determination of cobalt, copper and zinc by energy dispersive X-ray fluorescence spectrometry after preconcentration on PAR-loaded ion-exchange resin.

    PubMed

    Jiang, Zi-Tao; Yu, Jimmy C; Liu, Ho-Yan

    2005-07-01

    A sensitive method for the preconcentration and determination of trace amounts of Co, Cu and Zn by energy-dispersive X-ray fluorescence spectrometry (EDXRF) has been developed. The method is based on the fact that 4-(2-pyridylazo)-resorcinol (PAR) loaded Dowex anion-exchange resin (PAR-resin) can effectively adsorb Co, Cu and Zn at pH 9.0 to form PAR-metal complexes. The detection limits for Co, Cu and Zn were 1.53, 0.31 and 0.21 ppb, respectively. The precisions for five replicate measurements of the three metals were 3.4, 2.7 and 2.1% RSD, and the calibration curves were linear up to 75 microg with correlation coefficients of 0.9975, 0.9980 and 0.9985, respectively. The method was successfully applied for the simultaneous determination of Co, Cu and Zn in seawater samples at ppb levels. PMID:16038508

  2. Energy-dispersive x-ray fluorescence spectroscopy and inductively coupled plasma emission spectrometry evaluated for multielement analysis in complex biological matrices.

    PubMed

    Irons, R D; Schenk, E A; Giauque, R D

    1976-12-01

    Energy-dispersive x-ray spectroscopy and inductively coupled plasma emission spectrometry were evaluated as methods for routine multielement analysis of biological material. Standard samples included Standard Reference Materials (National Bureau of Standards), compounded mixtures, and supplements that provided a wide range of elemental concentrations for analysis. Elements included in this study were Zn, Pb, Ni, Mn, Fe, Mg, Cu, Ca, As, Se, Br, Rb, and Sr. Standards were analyzed as unknowns by participating laboratories. The two methods were evaluated for sensitivity, precision, and accuracy, and the results compared to those obtained for atomic absorption spectrometric analysis of identical standard unknowns. Both methods compared favorably and both were determined to be highly reliable for such an application. Advantages and disadvantages of each method are compared and discussed. PMID:1000800

  3. On the absence of a positive sound dispersion in the THz dynamics of glycerol: an inelastic x-ray scattering study

    SciTech Connect

    Cunsolo, Alessandro (BNL)

    2012-10-23

    The high frequency transport properties of glycerol are derived from inelastic x-ray scattering spectra measured at different pressures and compared with ultrasound absorption data. As a result, the presence of two distinct relaxation processes is inferred: a slow one, occurring in the GHz window and having an essentially structural character, and a fast one, related instead to microscopic degrees of freedom. While the former originates a neat increase of the apparent, i.e. frequency-dependent, sound velocity, the latter induces no visible dispersive effects on the acoustic propagation. The observed behavior is likely paradigmatic of all glass formers near or below the melting and it is here discussed and explained in some detail.

  4. Femtosecond x-ray absorption spectroscopy with hard x-ray free electron laser

    SciTech Connect

    Katayama, Tetsuo; Togashi, Tadashi; Tono, Kensuke; Kameshima, Takashi [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan)] [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Inubushi, Yuichi; Sato, Takahiro; Hatsui, Takaki; Yabashi, Makina [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)] [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Obara, Yuki; Misawa, Kazuhiko [Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan)] [Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan); Bhattacharya, Atanu; Kurahashi, Naoya [Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan)] [Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan); Ogi, Yoshihiro [Molecular Reaction Dynamics Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako 351-0198 (Japan)] [Molecular Reaction Dynamics Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako 351-0198 (Japan); Suzuki, Toshinori [Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan) [Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan); Molecular Reaction Dynamics Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako 351-0198 (Japan)

    2013-09-23

    We have developed a method of dispersive x-ray absorption spectroscopy with a hard x-ray free electron laser (XFEL), generated by a self-amplified spontaneous emission (SASE) mechanism. A transmission grating was utilized for splitting SASE-XFEL light, which has a relatively large bandwidth (?E/E ? 5 × 10{sup ?3}), into several branches. Two primary split beams were introduced into a dispersive spectrometer for measuring signal and reference spectra simultaneously. After normalization, we obtained a Zn K-edge absorption spectrum with a photon-energy range of 210 eV, which is in excellent agreement with that measured by a conventional wavelength-scanning method. From the analysis of the difference spectra, the noise ratio was evaluated to be ?3 × 10{sup ?3}, which is sufficiently small to trace minute changes in transient spectra induced by an ultrafast optical laser. This scheme enables us to perform single-shot, high-accuracy x-ray absorption spectroscopy with femtosecond time resolution.

  5. Study of properties of chemically modified samples of halloysite mineral with X-ray fluorescence and X-ray powder diffraction methods

    NASA Astrophysics Data System (ADS)

    Bana?, D.; Kubala-Kuku?, A.; Braziewicz, J.; Majewska, U.; Pajek, M.; Wudarczyk-Mo?ko, J.; Czech, K.; Garnuszek, M.; S?omkiewicz, P.; Szczepanik, B.

    2013-12-01

    Elemental and chemical composition of raw and activated samples of halloysite mineral using wavelength dispersive X-ray fluorescence (WDXRF), total reflection X-ray fluorescence (TXRF) and X-ray powder diffraction (XRPD) methods were determined. As the result, it has been shown that application of the complementary X-ray spectrometry techniques allows very precise observation of changes in composition of halloysite mineral samples caused by its chemical modifications. Sample preparation procedure and usability of the research methods applied are described in details. Procedure of activation of raw halloysite mineral samples by etching them in sulfuric acid of various concentrations has been described and discussed. The ability of the samples to adsorb lead from intentionally contaminated water was tested and confirmed.

  6. Determination of phosphorus in food samples by X-ray fluorescence spectrometry and standard spectrophotometric method

    Microsoft Academic Search

    A Jastrz?bska; B Brudka; T Szyma?ski; E Sz?yk

    2003-01-01

    The Wavelength Dispersive X-ray fluorescence (WD XRF) determination of phosphorus in GMO and non GMO food samples is proposed. The tested materials included commercially available transgenic, unmodified soya-foods and popular dairy products. The WD XRF method was compared with the standard molybdenum blue method. Matrix effects were minimised by using standard reference material. Obtained results were discussed in respect of

  7. EMPIRICAL BACKGROUND CALCULATION METHOD FOR MULTI-CHANNEL X-RAY SPECTROMETERS

    EPA Science Inventory

    A method of background calculation has been developed which is applicable to fixed-channel wavelength-dispersive spectrometers which cannot directly measure background. The x-ray intensities from a set of high- and low-average atomic number standards are fitted against Rayleigh a...

  8. X-Ray Imaging

    Cancer.gov

    X-ray imaging is perhaps the most familiar type of imaging. Images produced by X-rays are due to the different absorption rates of different tissues. Calcium in bones absorbs X-rays the most, so bones look white on a film recording of the X-ray image,

  9. X-Ray Optics

    NASA Astrophysics Data System (ADS)

    Schroer, Christian G.; Lengeler, Bruno

    Due to the weak interaction of hard x-rays with matter it is generally difficult to manipulate x-rays by optical components. As a result, there have been many complementary approaches to making x-ray optics, exploiting refraction, reflection, and diffraction of x-rays by matter. In this chapter, we describe the physics that underly x-ray optics and explain the working principles and performances of a variety of x-ray optics, including refractive x-ray lenses, reflective optics, such as mirrors and waveguides, and diffractive optics,such as multilayer and crystal optics and Fresnel zone plates.

  10. High-throughput baggage scanning employing x-ray diffraction for accurate explosives detection

    NASA Astrophysics Data System (ADS)

    Green, Michael C.; Partain, Larry D.

    2003-07-01

    X-ray systems dominate the installed base of airport baggage scanning systems for explosives detection. The majority are conveyer systems with projection line scanners. These systems can achieve a high throughput but exhibit a high false positive rate and require significant operator involvement. Systems employing computed tomography (CT) are currently being installed at a rapid rate. These can provide good discrimination of levels of xray absorption coefficient and can largely circumvent superimposition effects. Nonetheless CT measures only x-ray absorption coefficient per voxel which does not provide a means of specific material identification resulting in many false positives, and it is relatively straightforward to configure explosive materials so that they are undetectable by CT systems. Diffraction-based x-ray systems present a solution to this problem. They detect and measure atomic layer spacings in crystalline and microcrystalline materials with high sensitivity. This provides a means of specific material identification. The majority of explosive compounds are well crystallized solids at room temperature. X-ray diffraction systems using both conventional wavelength-dispersive diffraction and fixed-angle, multi-wavelength diffraction for improved throughput are described. Large-area, flat-panel x-ray detector technology coupled with an extended x-ray source will permit a full 3D volumetric x-ray diffraction scan of a bag in a single pass, (patent pending).

  11. Kinetic Modeling of the X-ray-induced Damage to a Metalloprotein

    PubMed Central

    Davis, Katherine M.; Kosheleva, Irina; Henning, Robert W.; Seidler, Gerald T.; Pushkar, Yulia

    2013-01-01

    It is well known that biological samples undergo x-ray-induced degradation. One of the fastest occurring x-ray-induced processes involves redox modifications (reduction or oxidation) of redox-active cofactors in proteins. Here we analyze room temperature data on the photoreduction of Mn ions in the oxygen evolving complex (OEC) of photosystem II, one of the most radiation damage sensitive proteins and a key constituent of natural photosynthesis in plants, green algae and cyanobacteria. Time-resolved x-ray emission spectroscopy with wavelength-dispersive detection was used to collect data on the progression of x-ray-induced damage. A kinetic model was developed to fit experimental results, and the rate constant for the reduction of OEC MnIII/IV ions by solvated electrons was determined. From this model, the possible kinetics of x-ray-induced damage at variety of experimental conditions, such as different rates of dose deposition as well as different excitation wavelengths, can be inferred. We observed a trend of increasing dosage threshold prior to the onset of x-ray-induced damage with increasing rates of damage deposition. This trend suggests that experimentation with higher rates of dose deposition is beneficial for measurements of biological samples sensitive to radiation damage, particularly at pink beam and x-ray FEL sources. PMID:23815809

  12. Applications of microfabrication technology to x-ray laser cavities

    Microsoft Academic Search

    Andrew M. Hawryluk; N. M. Ceglio; D. G. Stearns

    1988-01-01

    We have fabricated new, efficient x-ray optical components (x-ray mirrors, beamsplitters, and highly dispersive multilayer mirrors) and have used them to build an x-ray laser cavity. With our laser cavity, we have demonstrated multipass amplification of soft x rays with significant enhancement (>20 x ) of the x-ray laser emission. This is an important first step in the ultimate conversion

  13. Characterization of individual submicrometer aerosol particles collected in Incheon, Korea, by quantitative transmission electron microscopy energy-dispersive X-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Geng, Hong; Kang, Sujin; Jung, Hae-Jin; ChoëL, Marie; Kim, Hyekyeong; Ro, Chul-Un

    2010-08-01

    For the last decade the Monte Carlo calculation method has been proven to be an excellent tool for accurately simulating electron-solid interactions in atmospheric individual particles of micrometer size. Although it was designed for application to scanning electron microscopy, in the present study it is demonstrated that the Monte Carlo calculation can also be applied in a quantitative single particle analysis using transmission electron microscopy (TEM) with an ultrathin window energy-dispersive X-ray (EDX) spectrometer with a high accelerating voltage (200 kV). By utilizing an iterative reverse Monte Carlo simulation combined with successive approximation, atomic elemental concentrations (including low-Z elements) of submicrometer standard particles were determined with high accuracy for electron beam refractory particles such as NaCl, KCl, SiO2, Fe2O3, Na2SO4, K2SO4, CaCO3, and CaSO4. On the basis of quantitative X-ray analysis together with morphological information from TEM images, overall 1638 submicrometer individual particles from 10 sets of aerosol samples collected in Incheon, Korea, were identified. The most frequently encountered particle types are carbonaceous and (NH4)2SO4/NH4HSO4-containing particles, followed by mineral (e.g., aluminosilicate, SiO2, CaCO3), sea salt, K-rich (e.g., K2SO4 and KCl), Fe-rich, fly ash, and transition or heavy-metal-containing (e.g., ZnSO4, ZnCl2, PbSO4) particles. The relative abundances of the submicrometer particle types vary among samples collected in different seasons and also depend on different air mass transport routes. This study demonstrates that the quantitative TEM-EDX individual particle analysis is a useful and reliable technique in characterizing urban submicrometer aerosol particles.

  14. Integrated sorption-energy-dispersive X-ray fluorescence detection for automatic determination of lead and cadmium in low-concentration solutions.

    PubMed

    Pérez-Serradilla, J A; Luque de Castro, M D

    2007-11-01

    Sorbent material packed in a PTFE laboratory-made flow cell located in the specimen holder of an energy-dispersive X-ray fluorescence (EDXRF) detector has been used for in situ solid-phase extraction (SPE) preconcentration-detection of metals. The flow cell was connected to a single-channel flow-injection (FI) manifold (for full automation of the steps and proper development of the method) by two PTFE tubes of 0.5-mm inner diameter introduced into the spectrometer specimen holder by a small orifice without distortion or modification of the instrument. The optical window open in the PTFE flow cell was adjusted to the X-ray irradiation zone of the spectrometer and fixed to it. The approach was tested by using both Pb and Cd aqueous solutions and a Dowex 50 cation-exchange resin as a sorbent, and flushing the sample through the flow cell for EDXRF measurements after removal of the sample matrix. The limits of detection and the limits of quantification (LOQs) thus obtained were 0.15 and 0.5 microg for Pb and 0.3 and 0.8 microg for Cd, respectively, values that allow the approach to be used for the analysis of drinking water by injecting a 100-mL sample into the FI manifold, taking into account the EC drinking water directives. The linear dynamic ranges are between the LOQ and 600 microg for both analytes. The method was validated by the standard addition method using tap-water samples. In addition, the integrated SPE-EDXRF approach enables the study of the variables influencing the sorption step-namely the effects of the volume of sample flushed through the column, concentrations of the analytes in the sample, breakthrough volume of the resin, elution profiles, sample pH and retention and elution flow rates-in an automatic, cheap, fast and precise way. PMID:17846752

  15. Determination of inorganic nutrients in wheat flour by laser-induced breakdown spectroscopy and energy dispersive X-ray fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Peruchi, Lidiane Cristina; Nunes, Lidiane Cristina; de Carvalho, Gabriel Gustinelli Arantes; Guerra, Marcelo Braga Bueno; de Almeida, Eduardo; Rufini, Iolanda Aparecida; Santos, Dário; Krug, Francisco José

    2014-10-01

    Laser-induced breakdown spectroscopy (LIBS) and energy dispersive X-ray fluorescence spectrometry (EDXRF) were evaluated for the determination of P, K, Ca, Mg, S, Fe, Cu, Mn and Zn in pressed pellets of wheat flours. EDXRF and LIBS calibration models were built with analytes mass fractions determined by inductively coupled plasma optical emission spectrometry after microwave-assisted acid digestion in a set of 25 wheat flour laboratory samples. Test samples consisted of pressed pellets prepared from wheat flour mixed with 30% mm- 1 cellulose binder. Experiments were carried out with a LIBS setup consisted of a Q-switched Nd:YAG laser and a spectrometer with Echelle optics and ICCD, and a benchtop EDXRF system fitted with a Rh target X-ray tube and a Si(Li) semiconductor detector. The correlation coefficients from the linear calibration models of P, K, Ca, Mg, S, Fe, Mn and Zn determined by LIBS and/or EDXRF varied from 0.9705 for Zn to 0.9990 for Mg by LIBS, and from 0.9306 for S to 0.9974 for K by EDXRF. The coefficients of variation of measurements varied from 1.2 to 20% for LIBS, and from 0.3 to 24% for EDXRF. The predictive capabilities based on RMSEP (root mean square error of prediction) values were appropriate for the determination of P, Ca, Mg, Fe, Mn and Zn by LIBS, and for P, K, S, Ca, Fe, and Zn by EDXRF. In general, results from the analysis of NIST SRM 1567a Wheat flour by LIBS and EDXRF were in agreement with their certified mass fractions.

  16. Development of X-ray laser media. Measurement of gain and development of cavity resonators for wavelengths near 130 angstroms, volume 3

    Microsoft Academic Search

    J. M. Forsyth

    1983-01-01

    In this document the authors summarize our investigation of the reflecting properties of X-ray multilayers. The breadth of this investigation indicates the utility of the difference equation formalism in the analysis of such structure. The formalism is particularly useful in analyzing multilayers whose structure is not a simple periodic bilayer. The complexity in structure can be either intentional, as in

  17. SIMULTANEOUS MULTI-WAVELENGTH OBSERVATIONS OF MAGNETIC ACTIVITY IN ULTRACOOL DWARFS. III. X-RAY, RADIO, AND Halpha ACTIVITY TRENDS IN M AND L DWARFS

    SciTech Connect

    Berger, E. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Basri, G. [Astronomy Department, University of California, Berkeley, CA 94720 (United States); Fleming, T. A.; Liebert, J. [Department of Astronomy and Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Giampapa, M. S. [National Solar Observatory, National Optical Astronomy Observatories, Tucson, AZ 85726 (United States); Gizis, J. E. [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); MartIn, E. [Instituto de AstrofIsica de Canarias, C/VIa Lactea s/n, E-38200 La Laguna, Tenerife (Spain); Phan-Bao, N. [Department of Physics, HCMIU, Vietnam National University Administrative Building, Block 6, Linh Trung Ward, Thu Duc District, HCM (Viet Nam); Rutledge, R. E. [Department of Physics, McGill University, 3600 University Street, Montreal, QC H3A 2T8 (Canada)

    2010-01-20

    As part of our on-going investigation into the magnetic field properties of ultracool dwarfs, we present simultaneous radio, X-ray, and Halpha observations of three M9.5-L2.5 dwarfs (BRI 0021-0214, LSR 060230.4+391059, and 2MASS J052338.2-140302). We do not detect X-ray or radio emission from any of the three sources, despite previous detections of radio emission from BRI 0021 and 2M0523-14. Steady and variable Halpha emission are detected from 2M0523-14 and BRI 0021, respectively, while no Halpha emission is detected from LSR 0602+39. Overall, our survey of nine M8-L5 dwarfs doubles the number of ultracool dwarfs observed in X-rays, and triples the number of L dwarfs, providing in addition the deepest limits to date, log(L{sub X}/L{sub bol}) approx< -5. With this larger sample we find the first clear evidence for a substantial reduction in X-ray activity, by about two orders of magnitude, from mid-M to mid-L dwarfs. We find that the decline in Halpha roughly follows L{sub Ha}lpha/L{sub bol} propor to 10{sup -0.4x(SP-6)} for SP >= 6, where SP = 0 for spectral type M0. In the radio band, however, the luminosity remains relatively unchanged from M0 to L4, leading to a substantial increase in L{sub rad}/L{sub bol}. Our survey also provides the first comprehensive set of simultaneous radio/X-ray/Halpha observations of ultracool dwarfs, and reveals a clear breakdown of the radio/X-ray correlation beyond spectral type M7, evolving smoothly from L{sub n}u{sub ,rad}/L{sub X} approx 10{sup -15.5} to approx10{sup -11.5} Hz{sup -1} over the narrow spectral-type range M7-M9. This breakdown reflects the substantial reduction in X-ray activity beyond M7, but its physical origin remains unclear since, as evidenced by the uniform radio emission, there is no drop in the field dissipation and particle acceleration efficiency. Based on the results of our survey, we conclude that a further investigation of magnetic activity in ultracool dwarfs will benefit from a two-pronged approach: multi-rotation observations of nearby known active sources and a snapshot survey of a large sample within approx50 pc to uncover rare flaring objects.

  18. Anomalous X-ray diffraction with soft X-ray synchrotron radiation.

    PubMed

    Carpentier, P; Berthet-Colominas, C; Capitan, M; Chesne, M L; Fanchon, E; Lequien, S; Stuhrmann, H; Thiaudière, D; Vicat, J; Zielinski, P; Kahn, R

    2000-07-01

    Anomalous diffraction with soft X-ray synchrotron radiation opens new possibilities in protein crystallography and materials science. Low-Z elements like silicon, phosphorus, sulfur and chlorine become accessible as new labels in structural studies. Some of the heavy elements like uranium exhibit an unusually strong dispersion at their M(V) absorption edge (lambdaMV = 3.497 A, E(MV) = 3545 eV) and so does thorium. Two different test experiments are reported here showing the feasibility of anomalous X-ray diffraction at long wavelengths with a protein containing uranium and with a salt containing chlorine atoms. With 110 electrons the anomalous scattering amplitude of uranium exceeds by a factor of 4 the resonance scattering of other strong anomalous scatterers like that of the lanthanides at their L(III) edge. The resulting exceptional phasing power of uranium is most attractive in protein crystallography using the multi-wavelength anomalous diffraction (MAD) method. The anomalous dispersion of an uranium derivative of asparaginyl-tRNA synthetase (hexagonal unit cell; a = 123.4 A, c = 124.4 A) has been measured for the first time at 4 wavelengths near the M(V) edge using the beamline ID1 of ESRF (Grenoble, France). The present set up allowed to measure only 30% of the possible reflections at a resolution of 4 A, mainly because of the low sensitivity of the CCD detector. In the second experiment, the dispersion of the intensity of 5 X-ray diffraction peaks from pentakismethylammonium undecachlorodibismuthate (PMACB, orthorhombic unit cell; a = 13.003 A, b = 14.038 A, c = 15.450 A) has been measured at 30 wavelengths near the K absorption edge of chlorine (lambdaK = 4.397 A, EK= 2819.6 eV). All reflections within the resolution range from 6.4 A to 3.4 A expected in the 20 degree scan were observed. The chemical state varies between different chlorine atoms of PMACB, and so does the dispersion of different Bragg peaks near the K-edge of chlorine. The results reflect the performance of the beamline ID1 of ESRF at wavelengths beyond 3 A at the end of 1998. A gain by a factor 100 for diffraction experiments with 4.4 A photons was achieved in Autumn 1999 when two focusing mirrors had been added to the X-ray optics. Further progress is expected from area detectors more sensitive to soft X-rays. Both CCD detectors and image plates would provide a gain of two orders of measured intensity. Image plates would have the additional advantage that they can be bent cylindrically and thus cover a larger solid angle in reciprocal space. In many cases, samples need to be cooled: closed and open systems are presented. A comparison with the state of art of soft X-ray diffraction, as it had been reached at HASYLAB (Hamburg, Germany), and as it is developing at the Brookhaven National Laboratory (USA), is given. PMID:10976874

  19. A rapid, dispersion-based wavelength-stepped and wavelength-swept laser for optical coherence tomography

    PubMed Central

    Tozburun, Serhat; Siddiqui, Meena; Vakoc, Benjamin J.

    2014-01-01

    Abstract: Optical-domain subsampling enables Fourier-domain OCT imaging at high-speeds and extended depth ranges while limiting the required acquisition bandwidth. To perform optical-domain subsampling, a wavelength-stepped rather than a wavelength-swept source is required. This preliminary study introduces a novel design for a rapid wavelength-stepped laser source that uses dispersive fibers in combination with a fast lithium-niobate modulator to achieve wavelength selection. A laser with 200 GHz wavelength-stepping and a sweep rate of 9 MHz over a 94 nm range at a center wavelength of 1550 nm is demonstrated. A reconfiguration of this source design to a continuous wavelength-swept light for conventional Fourier-domain OCT is also demonstrated. PMID:24663631

  20. Portable total reflection x-ray fluorescence analysis in the identification of unknown laboratory hazards

    SciTech Connect

    Liu, Ying, E-mail: liu.ying.48r@st.kyoto-u.ac.jp; Imashuku, Susumu; Sasaki, Nobuharu; Ze, Long; Kawai, Jun [Department of Materials Science and Engineering, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501 (Japan); Takano, Shotaro; Sohrin, Yoshiki [Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Seki, Hiroko; Miyauchi, Hiroya [Kyoto Prefectural Technology Center for Small and Medium Enterprises, Chudojiminami machi, Shimogyo-ku, Kyoto 600-8813 (Japan)

    2014-05-15

    In this study, a portable total reflection x-ray fluorescence (TXRF) spectrometer was used to analyze unknown laboratory hazards that precipitated on exterior surfaces of cooling pipes and fume hood pipes in chemical laboratories. With the aim to examine the accuracy of TXRF analysis for the determination of elemental composition, analytical results were compared with those of wavelength-dispersive x-ray fluorescence spectrometry, scanning electron microscope and energy-dispersive x-ray spectrometry, energy-dispersive x-ray fluorescence spectrometry, inductively coupled plasma atomic emission spectrometry, x-ray diffraction spectrometry (XRD), and x-ray photoelectron spectroscopy (XPS). Detailed comparison of data confirmed that the TXRF method itself was not sufficient to determine all the elements (Z?>?11) contained in the samples. In addition, results suggest that XRD should be combined with XPS in order to accurately determine compound composition. This study demonstrates that at least two analytical methods should be used in order to analyze the composition of unknown real samples.

  1. The Need for X-Ray Spectroscopy

    NASA Technical Reports Server (NTRS)

    Winebarger, Amy R.; Cirtain, Jonathan; Kobayashi, Ken

    2011-01-01

    For over four decades, X-ray, EUV, and UV spectral observations have been used to measure physical properties of the solar atmosphere. During this time, there has been substantial improvement in the spectral, spatial, and temporal resolution of the observations for the EUV and UV wavelength ranges. At wavelengths below 100 Angstroms, however, observations of the solar corona with simultaneous spatial and spectral resolution are limited, and not since the late 1970's have spatially resolved solar X-ray spectra been measured. The soft-X-ray wavelength range is dominated by emission lines formed at high temperatures and provides diagnostics unavailable in any other wavelength range. In this presentation, we will discuss the important science questions that can be answered using spatially and spectrally resolved X-ray spectra.

  2. Multiple scattering in dispersions, for long wavelength thermoacoustic solutions

    NASA Astrophysics Data System (ADS)

    Hazlehurst, T. A.; Harlen, O. G.; Holmes, M. J.; Povey, M. J. W.

    2014-04-01

    Thermoacoustic scattering is a principal scattering mechanism in the ultrasonic characterisation of water-continuous colloids. Thermal effects are particularly important in highly concentrated systems, where non-propagational thermal fields surrounding the disperse particles overlap. For low concentrations, the single sphere solution of Epstein and Carhart has become a popular tool for determining the particle size distribution. However, for small particle sizes it suffers from ill-conditioning that can make the solution numerically unstable. This problem has been resolved, by Harlen et. al. (2001, SIAM Journal on Applied Mathematics, 61 1906-1931), who obtained an asymptotic solution for low concentrations that is valid when the particle diameter is small compared to the wavelength. In this paper we will use this asymptotic method to calculate the effects of multiple scattering that occur at higher concentrations. We use the addition translation theorem to calculate the effects of multiple scattering between a pair of spheres of different sizes and show how this affects the close-field scattering pattern.

  3. Controlling X-rays with light

    NASA Astrophysics Data System (ADS)

    Glover, T. E.; Hertlein, M. P.; Southworth, S. H.; Allison, T. K.; van Tilborg, J.; Kanter, E. P.; Krässig, B.; Varma, H. R.; Rude, B.; Santra, R.; Belkacem, A.; Young, L.

    2010-01-01

    Ultrafast X-ray science is an exciting frontier that promises the visualization of electronic, atomic and molecular dynamics on atomic time and length scales. A largely unexplored area of ultrafast X-ray science is the use of light to control how X-rays interact with matter. To extend control concepts established for long-wavelength probes to the X-ray regime, the optical control field must drive a coherent electronic response on a timescale comparable to femtosecond core-hole lifetimes. An intense field is required to achieve this rapid response. Here, an intense optical control pulse is observed to efficiently modulate photoelectric absorption for X-rays and to create an ultrafast transparency window. We demonstrate an application of X-ray transparency relevant to ultrafast X-ray sources: an all-photonic temporal cross-correlation measurement of a femtosecond X-ray pulse. The ability to control X-ray-matter interactions with light will create new opportunities for present and next-generation X-ray light sources.

  4. Ultrafast X-ray Sources

    SciTech Connect

    George Neil

    2010-04-19

    Since before the scattering of X-rays off of DNA led to the first understanding of the double helix structure, sources of X-rays have been an essential tool for scientists examining the structure and interactions of matter. The resolution of a microscope is proportional to the wavelength of light so x-rays can see much finer structures than visible light, down to single atoms. In addition, the energy of X-rays is resonant with the core atomic levels of atoms so with appropriate wavelengths the placement of specific atoms in a large molecule can be determined. Over 10,000 scientists use synchrotron sources, storage rings of high energy electrons, each year worldwide. As an example of such use, virtually every picture of a protein or drug molecule that one sees in the scientific press is a reconstruction based on X-ray scattering of synchrotron light from the crystallized form of that molecule. Unfortunately those pictures are static and proteins work through configuration (shape) changes in response to energy transfer. To understand how biological systems work requires following the energy flow to these molecules and tracking how shape changes drive their interaction with other molecules. We'd like to be able to freeze the action of these molecules at various steps along the way with an X-ray strobe light. How fast does it have to be? To actually get a picture of a molecule in a fixed configuration requires X-ray pulses as short as 30 femtoseconds (1/30 of a millionth of a millionth of a second). To capture the energy flow through changes in electronic levels requires a faster strobe, less than 1 femtosecond! And to acquire such information in smaller samples with higher accuracy demands brighter and brighter X-rays. Unfortunately modern synchrotrons (dubbed 3rd Generation Light Sources) cannot deliver such short bright pulses of X-rays. An entirely new approach is required, linear-accelerator (linac-)-based light sources termed 4th or Next Generation Light Sources (NGLSs). Although NGLSs will not displace synchrotrons from their role they do offer exciting new capabilities which can be understood from the physics of the light production in each device.

  5. Post-mortem interval estimation of human skeletal remains by micro-computed tomography, mid-infrared microscopic imaging and energy dispersive X-ray mapping

    PubMed Central

    Hatzer-Grubwieser, P.; Bauer, C.; Parson, W.; Unterberger, S. H.; Kuhn, V.; Pemberger, N.; Pallua, Anton K.; Recheis, W.; Lackner, R.; Stalder, R.; Pallua, J. D.

    2015-01-01

    In this study different state-of-the-art visualization methods such as micro-computed tomography (micro-CT), mid-infrared (MIR) microscopic imaging and energy dispersive X-ray (EDS) mapping were evaluated to study human skeletal remains for the determination of the post-mortem interval (PMI). PMI specific features were identified and visualized by overlaying molecular imaging data and morphological tissue structures generated by radiological techniques and microscopic images gained from confocal microscopy (Infinite Focus (IFM)). In this way, a more distinct picture concerning processes during the PMI as well as a more realistic approximation of the PMI were achieved. It could be demonstrated that the gained result in combination with multivariate data analysis can be used to predict the Ca/C ratio and bone volume (BV) over total volume (TV) for PMI estimation. Statistical limitation of this study is the small sample size, and future work will be based on more specimens to develop a screening tool for PMI based on the outcome of this multidimensional approach.

  6. Determination of tacrolimus crystalline fraction in the commercial immediate release amorphous solid dispersion products by a standardized X-ray powder diffraction method with chemometrics.

    PubMed

    Rahman, Ziyaur; Siddiqui, Akhtar; Bykadi, Srikant; Khan, Mansoor A

    2014-11-20

    Clinical performance of an amorphous solid dispersion (ASD) drug product is related to the amorphous drug content because of the greater bioavailability of this form of the drug than its crystalline form. Therefore, it is paramount to monitor the amorphous and the crystalline fractions in the ASD products. The objective of the present investigation was to study the feasibility of using a standardized X-ray powder diffraction (XRPD) in conjunction with chemometric methods to quantitate the amorphous and crystalline fraction of the drug in several tacrolimus ASD products. Three ASD products were prepared in which drug to excipients ratios ranged from 1:19 to 1:49. The amorphous and crystalline drug products were mixed in various proportions so that amorphous/crystalline tacrolimus in the samples vary from 0 to 100%. XRPD of the samples of the drug products were collected, and PLSR and PCR chemometric methods were applied to the data. The R(2) was greater than '0.987' for all the models and bias in the models were statistically insignificant (p>0.05). RMSEP and SEP values were smaller for PLSR models than PCR models. The models prediction capabilities were good and can predict as low as 10% when drug to excipient ratio is as high as 1:49. In summary, XRPD and chemometric provide powerful analytical tools to monitor the crystalline fractions of the drug in the ASD products. PMID:25173870

  7. In Vitro assessment of dentin erosion after immersion in acidic beverages: surface profile analysis and energy-dispersive X-ray fluorescence spectrometry study.

    PubMed

    Caneppele, Taciana Marco Ferraz; Jeronymo, Raffaela Di Iorio; Di Nicoló, Rebeca; de Araújo, Maria Amélia Máximo; Soares, Luís Eduardo Silva

    2012-01-01

    The aim of this study was to investigate the effects of some acidic drinks on dentin erosion, using methods of surface profile (SP) analysis and energy-dispersive X-ray fluorescence spectrometry (EDXRF). One hundred standardized dentin slabs obtained from bovine incisor roots were used. Dentin slabs measuring 5x5 mm were ground flat, polished and half of each specimen surface was protected with nail polish. For 60 min, the dentin surfaces were immersed in 50 mL of 5 different drinks (Gatorade®, Del Valle Mais orange juice®, Coca-Cola®, Red Bull® and white wine), 20 blocks in each drink. The pH of each beverage was measured. After the erosive challenge, the nail polish was removed and SP was analyzed. The mineral concentration of dentin surfaces was determined by means of EDXRF. Data were analyzed statistically by ANOVA and Tukey's test (?=0.05). SP analysis showed that Red-Bull had the highest erosive potential (p<0.05). EDXRF results exhibited a decrease in phosphate in the groups immersed in Red-Bull, orange juice and white wine (p<0.05), and no significant difference in calcium content between the reference surface and eroded surface. In conclusion, this study demonstrated that all studied beverages promoted erosion on root dentin and Red Bull had the highest erosive potential. There was no correlation between pH of beverages and their erosive potential and only the P content changed after erosive challenge. PMID:23207852

  8. In situ energy-dispersive X-ray diffraction for the synthesis optimization and scale-up of the porous zirconium terephthalate UiO-66.

    PubMed

    Ragon, Florence; Horcajada, Patricia; Chevreau, Hubert; Hwang, Young Kyu; Lee, U-Hwang; Miller, Stuart R; Devic, Thomas; Chang, Jong-San; Serre, Christian

    2014-03-01

    The synthesis optimization and scale-up of the benchmarked microporous zirconium terephthalate UiO-66(Zr) were investigated by evaluating the impact of several parameters (zirconium precursors, acidic conditions, addition of water, and temperature) over the kinetics of crystallization by time-resolved in situ energy-dispersive X-ray diffraction. Both the addition of hydrochloric acid and water were found to speed up the reaction. The use of the less acidic ZrOCl2·8H2O as the precursor seemed to be a suitable alternative to ZrCl4·xH2O, avoiding possible reproducibility issues as a consequence of the high hygroscopic character of ZrCl4. ZrOCl2·8H2O allowed the formation of smaller good quality UiO-66(Zr) submicronic particles, paving the way for their use within the nanotechnology domain, in addition to higher reaction yields, which makes this synthesis route suitable for the preparation of UiO-66(Zr) at a larger scale. In a final step, UiO-66(Zr) was prepared using conventional reflux conditions at the 0.5 kg scale, leading to a rather high space-time yield of 490 kg m(-3) day(-1), while keeping physicochemical properties similar to those obtained from smaller scale solvothermally prepared batches. PMID:24527942

  9. Elemental relationships in rock varnish as seen with SEM/EDX (scanning electron microscopy/energy dispersive x-ray) elemental line profiling

    SciTech Connect

    Raymond, R. Jr.; Reneau, S.L.; Harrington, C.D.

    1990-01-01

    The heterogeneous nature of rock varnish requires a thorough survey of elemental and mineralogic compositions before relating chemical variability of rock varnish to past geochemical environments. Elemental relationships in rock varnish can be examined using scanning electron microscopy (SEM) in conjunction with an elemental line profiling routine using semi-quantitative, energy dispersive x-ray (EDX) analysis. Results of SEM/EDX analysis suggest: variations in cation concentrations used in varnish cation ratio dating relate more specifically to variations in detritus within the varnish than to element mobility as defined by weathering indices; Mn concentration rather than Mn:Fe ratios may be a more appropriate indicator of paleoclimatic fluctuations; and the Mn-oxide phase existing in varnish is most likely a Ba-enriched phase rather than birnessite. Element line profiling offers great potential for gaining insights into geochemical processes affecting the deposition and diagenesis of rock varnish and for testing hypotheses relating to its chemical variability. 27 refs., 9 figs.

  10. Abdominal x-ray

    MedlinePLUS

    Abdominal film; X-ray - abdomen; Flat plate; KUB x-ray ... Diagnose a pain in the abdomen or unexplained nausea Identify suspected problems in the urinary system, such as a kidney stone Identify blockage in the intestine Locate ...

  11. Demonstration of enhanced iodine K-edge imaging using an energy-dispersive X-ray computed tomography system with a 25 mm/s-scan linear cadmium telluride detector and a single comparator.

    PubMed

    Sato, Eiichi; Oda, Yasuyuki; Abudurexiti, Abulajiang; Hagiwara, Osahiko; Matsukiyo, Hiroshi; Osawa, Akihiro; Enomoto, Toshiyuki; Watanabe, Manabu; Kusachi, Shinya; Sato, Shigehiro; Ogawa, Akira; Onagawa, Jun

    2012-05-01

    An energy-dispersive (ED) X-ray computed tomography (CT) system is useful for carrying out monochromatic imaging. To perform enhanced iodine K-edge CT, we developed an oscillation linear cadmium telluride (CdTe) detector with a scan velocity of 25 mm/s and an energy resolution of 1.2 keV. CT is performed by repeated linear scans and rotations of an object. Penetrating X-ray photons from the object are detected by the CdTe detector, and event signals of X-ray photons are produced using charge-sensitive and shaping amplifiers. The lower photon energy is determined by a comparator device, and the maximum photon energy of 60 keV corresponds to the tube voltage. Rectangular-shaped comparator outputs are counted by a counter card. In the ED-CT, tube voltage and current were 60 kV and 0.30 mA, respectively, and X-ray intensity was 14.8 ?Gy/s at 1.0m from the source at a tube voltage of 60 kV. Demonstration of enhanced iodine K-edge X-ray CT for cancer diagnosis was carried out by selecting photons with energies ranging from 34 to 60 keV. PMID:22364788

  12. Sinus x-ray

    MedlinePLUS

    Paranasal sinus radiography; X-ray - sinuses ... sinus x-ray is taken in a hospital radiology department. Or the x-ray may be taken ... Anslow P. Ear, nose and throat radiology. In: Adam A, Dixon AK, ... Radiology: A Textbook of Medical Imaging . 5th ed. Philadelphia, ...

  13. Dispersive liquid-liquid microextraction using diethyldithiocarbamate as a chelating agent and the dried-spot technique for the determination of Fe, Co, Ni, Cu, Zn, Se and Pb by energy-dispersive X-ray fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Kocot, Karina; Zawisza, Beata; Sitko, Rafal

    2012-07-01

    Dispersive liquid-liquid microextraction (DLLME) using sodium diethyldithiocarbamate (DDTC) as a chelating agent was investigated for the simultaneous determination of iron, cobalt, nickel, copper, zinc, selenium and lead ions in water samples. The procedure was performed using 5 mL of the sample, 100 ?L of a 0.5% solution of DDTC, 30 ?L of carbon tetrachloride (extraction phase) and 500 ?L of methanol (disperser solvent). The experiments showed that Fe, Co, Ni, Cu, Zn and Pb can be simultaneously extracted at a pH of 5 and that Se can be extracted at a pH of 2-3. The results were compared with those obtained using ammonium pyrrolidine dithiocarbamate as a chelating agent. For all analytes, a linear range was observed up to 0.4 ?g mL- 1. If Fe and Zn are present in concentrations 10 times higher than those of the other analytes, then the linearity is observed up to 0.2 ?g mL- 1. In the present study, the organic phase that contained preconcentrated elements was deposited onto a Millipore filter and measured using energy-dispersive X-ray fluorescence spectrometry. The obtained detection limits were 2.9, 1.5, 2.0, 2.3, 2.5, 2.0 and 3.9 ng mL- 1 for Fe, Co, Ni, Cu, Zn, Se and Pb, respectively. This combination of DLLME and the dried-spot technique is promising for multielement analyses using other spectroscopy techniques, such as laser ablation-inductively coupled plasma-mass spectrometry, laser-induced breakdown spectroscopy or total-reflection X-ray fluorescence spectrometry.

  14. X-rays from Hot Stars: Stellar Astronomy Research with

    E-print Network

    Cohen, David

    , and the effects of x-ray absorption in the wind all affect the line shapes. #12;Stephanie Tonnesen ('03) modeled emitted only over a few narrow wavelength ranges #12;Like any wave phenomenon, x-ray light is subject a model for fitting the detailed shapes of x-ray emission line profiles from hot star winds The very hot

  15. X-Ray Supernovae

    E-print Network

    Stefan Immler; Walter H. G. Lewin

    2002-03-27

    We present a review of X-ray observations of supernovae (SNe). By observing the (~0.1-100 keV) X-ray emission from young SNe, physical key parameters such as the circumstellar matter (CSM) density, mass-loss rate of the progenitor and temperature of the outgoing and reverse shock can be derived as a function of time. Despite intensive search over the last ~25 years, only 15 SNe have been detected in X-rays. We review the individual X-ray observations of these SNe and discuss their implications as to our understanding of the physical processes giving rise to the X-ray emission.

  16. Analysis of eight argonne premium coal samples by X-ray fluorescence spectrometry

    USGS Publications Warehouse

    Evans, J.R.; Sellers, G.A.; Johnson, R.G.; Vivit, D.V.; Kent, J.

    1990-01-01

    X-ray fluorescence spectrometric methods were used in the analysis of eight Argonne Premium Coal Samples. Trace elements (Cr, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, La, and Ce) in coal ash were determined by energy-dispersive X-ray fluorescence spectrometry; major elements (Na, Mg, Al, Si, P, S, K, Ca, Ti, Mn, and Fe) in coal ash and trace elements (Cl and P) in whole coal were determined by wavelength-dispersive X-ray fluorescence spectrometry. The results of this study will be used in a geochemical database compiled for these materials from various analytical techniques. The experimental XRF methods and procedures used to determine these major and trace elements are described.

  17. The effect of silica on polymorphic precipitation of calcium carbonate: an on-line energy-dispersive X-ray diffraction (EDXRD) study

    NASA Astrophysics Data System (ADS)

    Kellermeier, Matthias; Glaab, Fabian; Klein, Regina; Melero-García, Emilio; Kunz, Werner; García-Ruiz, Juan Manuel

    2013-07-01

    Calcium carbonate is the most abundant biomineral and a compound of great industrial importance. Its precipitation from solution has been studied extensively and was often shown to proceed via distinct intermediate phases, which undergo sequential transformations before eventually yielding the stable crystalline polymorph, calcite. In the present work, we have investigated the crystallisation of calcium carbonate in a time-resolved and non-invasive manner by means of energy-dispersive X-ray diffraction (EDXRD) using synchrotron radiation. In particular, the role of silica as a soluble additive during the crystallisation process was examined. Measurements were carried out at different temperatures (20, 50 and 80 °C) and various silica concentrations. Experiments conducted in the absence of silica reflect the continuous conversion of kinetically formed metastable polymorphs (vaterite and aragonite) to calcite and allow for quantifying the progress of transformation. Addition of silica induced remarkable changes in the temporal evolution of polymorphic fractions existing in the system. Essentially, the formation of calcite was found to be accelerated at 20 °C, whereas marked retardation or complete inhibition of phase transitions was observed at higher temperatures. These findings are explained in terms of a competition between the promotional effect of silica on calcite growth rates and kinetic stabilisation of vaterite and aragonite due to adsorption (or precipitation) of silica on their surfaces, along with temperature-dependent variations of silica condensation rates. Data collected at high silica concentrations indicate the presence of an amorphous phase over extended frames of time, suggesting that initially generated ACC particles are progressively stabilised by silica. Our results may have important implications for CaCO3 precipitation scenarios in both geochemical and industrial settings, where solution silicate is omnipresent, as well as for CO2 sequestration technologies.Calcium carbonate is the most abundant biomineral and a compound of great industrial importance. Its precipitation from solution has been studied extensively and was often shown to proceed via distinct intermediate phases, which undergo sequential transformations before eventually yielding the stable crystalline polymorph, calcite. In the present work, we have investigated the crystallisation of calcium carbonate in a time-resolved and non-invasive manner by means of energy-dispersive X-ray diffraction (EDXRD) using synchrotron radiation. In particular, the role of silica as a soluble additive during the crystallisation process was examined. Measurements were carried out at different temperatures (20, 50 and 80 °C) and various silica concentrations. Experiments conducted in the absence of silica reflect the continuous conversion of kinetically formed metastable polymorphs (vaterite and aragonite) to calcite and allow for quantifying the progress of transformation. Addition of silica induced remarkable changes in the temporal evolution of polymorphic fractions existing in the system. Essentially, the formation of calcite was found to be accelerated at 20 °C, whereas marked retardation or complete inhibition of phase transitions was observed at higher temperatures. These findings are explained in terms of a competition between the promotional effect of silica on calcite growth rates and kinetic stabilisation of vaterite and aragonite due to adsorption (or precipitation) of silica on their surfaces, along with temperature-dependent variations of silica condensation rates. Data collected at high silica concentrations indicate the presence of an amorphous phase over extended frames of time, suggesting that initially generated ACC particles are progressively stabilised by silica. Our results may have important implications for CaCO3 precipitation scenarios in both geochemical and industrial settings, where solution silicate is omnipresent, as well as for CO2 sequestration technologies. Electronic supplementary information (ESI) available: Additiona

  18. A von Hamos x-ray spectrometer based on a segmented-type diffraction crystal for single-shot x-ray emission spectroscopy and time-resolved resonant inelastic x-ray scattering studies

    SciTech Connect

    Szlachetko, J. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Nachtegaal, M.; Boni, E. de; Willimann, M.; Safonova, O.; Sa, J.; Smolentsev, G.; Szlachetko, M.; Bergamaschi, A.; Schmitt, B.; David, C.; Luecke, A. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Bokhoven, J. A. van [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Institute for Chemical and Bioengineering, ETH Zurich, 8093 Zuerich (Switzerland); Dousse, J.-Cl.; Hoszowska, J.; Kayser, Y. [Department of Physics, University of Fribourg, 1700 Fribourg (Switzerland); Jagodzinski, P. [University of Technology, Kielce (Poland)

    2012-10-15

    We report on the design and performance of a wavelength-dispersive type spectrometer based on the von Hamos geometry. The spectrometer is equipped with a segmented-type crystal for x-ray diffraction and provides an energy resolution in the order of 0.25 eV and 1 eV over an energy range of 8000 eV-9600 eV. The use of a segmented crystal results in a simple and straightforward crystal preparation that allows to preserve the spectrometer resolution and spectrometer efficiency. Application of the spectrometer for time-resolved resonant inelastic x-ray scattering and single-shot x-ray emission spectroscopy is demonstrated.

  19. Elemental analysis and fine structure of mitochondrial granules in growth plate chondrocytes studied by electron energy loss spectroscopy and energy dispersive X-ray microanalysis.

    PubMed

    Wroblewski, J; Wróblewski, R; Mory, C; Colliex, C

    1991-09-01

    Electron energy loss spectrometry--EELS, and energy dispersive X-ray microanalysis--XRMA, were used to study the elemental composition of mitochondrial dense granules-mdg. The study was performed on dry cut thin sections (80-200 nm) of freeze-dried and low temperature embedded cartilage. Results obtained by means of XRMA clearly showed high phosphorus and calcium content in the mdg. Using EELS at 100 kV primary voltage we found that small concentrations of elements (i.e. below typically 1% atomic weight) are difficult to analyze and map, this especially in sections thicker than 50-60 nm. Surprisingly, analysis of calcium can be successfully performed on thicker sections though the edge lies above the carbon K edge while this is not possible for the phosphorus edge which is located at lower energies. This is likely due to the edge shapes (sharp for calcium and delayed for phosphorus), and to the more intense contribution of multiple low loss scattering in the background for phosphorus between 100 and 130 eV. By means of EELS elemental mapping a centrally located core was found in numerous mdg. In the calcium map the signal was strongest in the middle of mdg which corresponds to the area of reduced carbon signal. We found that carbon maps might be used for high resolution structural studies of chemically unfixed and anhydrously processed biological tissues. As carbon is the main constituent of Lowicryl resin its distribution is reversed to the distribution of biological tissue in which the proportion of carbon is lower, but is proportional to water content in the specimen in vivo. Use of EELS in combination with electron microscope with accelerating voltages in range of 140-200 kV together with anhydrous techniques of the tissue preparation will provide a new type of information which might lead to better understanding of the etiology and function of small structures in the cell. PMID:1808719

  20. Quantitative determination of low-Z elements in single atmospheric particles on boron substrates by automated scanning electron microscopy-energy-dispersive X-ray spectrometry.

    PubMed

    Choël, Marie; Deboudt, Karine; Osán, János; Flament, Pascal; Van Grieken, René

    2005-09-01

    Atmospheric aerosols consist of a complex heterogeneous mixture of particles. Single-particle analysis techniques are known to provide unique information on the size-resolved chemical composition of aerosols. A scanning electron microscope (SEM) combined with a thin-window energy-dispersive X-ray (EDX) detector enables the morphological and elemental analysis of single particles down to 0.1 microm with a detection limit of 1-10 wt %, low-Z elements included. To obtain data statistically representative of the air masses sampled, a computer-controlled procedure can be implemented in order to run hundreds of single-particle analyses (typically 1000-2000) automatically in a relatively short period of time (generally 4-8 h, depending on the setup and on the particle loading). However, automated particle analysis by SEM-EDX raises two practical challenges: the accuracy of the particle recognition and the reliability of the quantitative analysis, especially for micrometer-sized particles with low atomic number contents. Since low-Z analysis is hampered by the use of traditional polycarbonate membranes, an alternate choice of substrate is a prerequisite. In this work, boron is being studied as a promising material for particle microanalysis. As EDX is generally said to probe a volume of approximately 1 microm3, geometry effects arise from the finite size of microparticles. These particle geometry effects must be corrected by means of a robust concentration calculation procedure. Conventional quantitative methods developed for bulk samples generate elemental concentrations considerably in error when applied to microparticles. A new methodology for particle microanalysis, combining the use of boron as the substrate material and a reverse Monte Carlo quantitative program, was tested on standard particles ranging from 0.25 to 10 microm. We demonstrate that the quantitative determination of low-Z elements in microparticles is achievable and that highly accurate results can be obtained using the automatic data processing described here compared to conventional methods. PMID:16131082

  1. Selective scavenging of copper, zinc, lead, and arsenic by iron and manganese oxyhydroxide coatings on plankton in lakes polluted with mine and smelter wastes: results of energy dispersive X-ray micro-analysis

    Microsoft Academic Search

    Togwell A. Jackson; Thomas Bistricki

    1995-01-01

    Energy dispersive X-ray micro-analyses of the remains of individual organisms in plankton samples, together with more conventional analyses of sediments and water, were performed for the purpose of investigating the accumulation of heavy metals by plankton in three Canadian Shield lakes polluted with Cu, Zn, Cd, Pb, As, and SO2?4 from a base metal mine and smelter. The results showed

  2. The identification of the pigments used to paint statues of Feixiange Cliff in China in late 19th century by micro-Raman spectroscopy and scanning electron microscopy\\/energy dispersive X-ray analysis

    Microsoft Academic Search

    Pu-jun Jin; Wei Huang; Jianhua-Wang; Gang Zhao; Xiao-ling Wang

    2010-01-01

    The application of micro-Raman spectroscopy (?-RS) and scanning electron microscopy (SEM)\\/energy dispersive X-ray spectrometer (EDS) to the research of pigments collected from Statues of Feixiange Cliff No. 67 and No. 69 niche of Tang Dynasty in China is reported. Five kinds of pigments were found in the experimental data, including black (carbon), white (gypsum+quartz), blue (lapis lazuli) and green (Paris

  3. Mass Calibration and Cosmological Analysis of the SPT-SZ Galaxy Cluster Sample Using Velocity Dispersion ? v and X-Ray Y X Measurements

    NASA Astrophysics Data System (ADS)

    Bocquet, S.; Saro, A.; Mohr, J. J.; Aird, K. A.; Ashby, M. L. N.; Bautz, M.; Bayliss, M.; Bazin, G.; Benson, B. A.; Bleem, L. E.; Brodwin, M.; Carlstrom, J. E.; Chang, C. L.; Chiu, I.; Cho, H. M.; Clocchiatti, A.; Crawford, T. M.; Crites, A. T.; Desai, S.; de Haan, T.; Dietrich, J. P.; Dobbs, M. A.; Foley, R. J.; Forman, W. R.; Gangkofner, D.; George, E. M.; Gladders, M. D.; Gonzalez, A. H.; Halverson, N. W.; Hennig, C.; Hlavacek-Larrondo, J.; Holder, G. P.; Holzapfel, W. L.; Hrubes, J. D.; Jones, C.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; Liu, J.; Lueker, M.; Luong-Van, D.; Marrone, D. P.; McDonald, M.; McMahon, J. J.; Meyer, S. S.; Mocanu, L.; Murray, S. S.; Padin, S.; Pryke, C.; Reichardt, C. L.; Rest, A.; Ruel, J.; Ruhl, J. E.; Saliwanchik, B. R.; Sayre, J. T.; Schaffer, K. K.; Shirokoff, E.; Spieler, H. G.; Stalder, B.; Stanford, S. A.; Staniszewski, Z.; Stark, A. A.; Story, K.; Stubbs, C. W.; Vanderlinde, K.; Vieira, J. D.; Vikhlinin, A.; Williamson, R.; Zahn, O.; Zenteno, A.

    2015-02-01

    We present a velocity-dispersion-based mass calibration of the South Pole Telescope Sunyaev-Zel'dovich effect survey (SPT-SZ) galaxy cluster sample. Using a homogeneously selected sample of 100 cluster candidates from 720 deg2 of the survey along with 63 velocity dispersion (? v ) and 16 X-ray Y X measurements of sample clusters, we simultaneously calibrate the mass-observable relation and constrain cosmological parameters. Our method accounts for cluster selection, cosmological sensitivity, and uncertainties in the mass calibrators. The calibrations using ? v and Y X are consistent at the 0.6? level, with the ? v calibration preferring ~16% higher masses. We use the full SPTCL data set (SZ clusters+? v +Y X) to measure ?8(?m/0.27)0.3 = 0.809 ± 0.036 within a flat ?CDM model. The SPT cluster abundance is lower than preferred by either the WMAP9 or Planck+WMAP9 polarization (WP) data, but assuming that the sum of the neutrino masses is ?m ? = 0.06 eV, we find the data sets to be consistent at the 1.0? level for WMAP9 and 1.5? for Planck+WP. Allowing for larger ?m ? further reconciles the results. When we combine the SPTCL and Planck+WP data sets with information from baryon acoustic oscillations and Type Ia supernovae, the preferred cluster masses are 1.9? higher than the Y X calibration and 0.8? higher than the ? v calibration. Given the scale of these shifts (~44% and ~23% in mass, respectively), we execute a goodness-of-fit test; it reveals no tension, indicating that the best-fit model provides an adequate description of the data. Using the multi-probe data set, we measure ?m = 0.299 ± 0.009 and ?8 = 0.829 ± 0.011. Within a ?CDM model we find ?m ? = 0.148 ± 0.081 eV. We present a consistency test of the cosmic growth rate using SPT clusters. Allowing both the growth index ? and the dark energy equation-of-state parameter w to vary, we find ? = 0.73 ± 0.28 and w = –1.007 ± 0.065, demonstrating that the expansion and the growth histories are consistent with a ?CDM universe (? = 0.55; w = –1).

  4. Large normal group velocity dispersion of micro/nano optical fiber near 2-?m wavelength

    NASA Astrophysics Data System (ADS)

    Zhang, Changchun; Chen, Yu; Mu, Wei; Zhao, Chujun

    2013-02-01

    Based on the exact solution of the Maxwell's equations, the group velocity dispersion characteristics of micro/nano optical fibers near 2-?m wavelength have been studied numerically. The results show that the micro/nano optical fiber has large normal dispersion near 2-?m wavelength by carefully choosing the core size. For air-clad micro/nano optical fiber with core size 900 nm, the group velocity dispersion can be up to 3318.78 ps2/km. By introducing a thin dielectric layer, the maximum dispersion can be adjusted by varying the thickness and refractive index of the dielectric layer.

  5. Investigation of Energy-Dispersive X-ray Computed Tomography System with CdTe Scan Detector and Comparing-Differentiator and Its Application to Gadolinium K-Edge Imaging

    NASA Astrophysics Data System (ADS)

    Chiba, Hiraku; Sato, Yuichi; Sato, Eiichi; Maeda, Tomoko; Matsushita, Ryo; Yanbe, Yutaka; Hagiwara, Osahiko; Matsukiyo, Hiroshi; Osawa, Akihiro; Enomoto, Toshiyuki; Watanabe, Manabu; Kusachi, Shinya; Sato, Shigehiro; Ogawa, Akira; Onagawa, Jun

    2012-10-01

    An energy-dispersive (ED) X-ray computed tomography (CT) system is useful for carrying out monochromatic imaging by selecting optimal energy photons. CT is performed by repeated linear scans and rotations of an object. X-ray photons from the object are detected by the cadmium telluride (CdTe) detector, and event pulses of X-ray photons are produced using charge-sensitive and shaping amplifiers. The lower photon energy is determined by a comparator, and the maximum photon energy of 70 keV corresponds to the tube voltage. Logical pulses from the comparator are counted by a counter card through a differentiator to reduce pulse width and rise time. In the ED-CT system, tube voltage and current were 70 kV and 0.30 mA, respectively, and X-ray intensity was 18.2 µGy/s at 1.0 m from the source at a tube voltage of 70 kV. Demonstration of gadolinium K-edge CT for cancer diagnosis was carried out by selecting photons with energies ranging from 50.4 to 70 keV, and photon-count energy subtraction imaging from 30 to 50.3 keV was also performed.

  6. X-ray Polarimetry

    NASA Astrophysics Data System (ADS)

    Bellazzini, Ronaldo; Costa, Enrico; Matt, Giorgio; Tagliaferri, Gianpiero

    2010-07-01

    1. X-ray polarimetry: historical remarks and other considerations; Part I. Polarimetry Techniques: 2. Scattering polarimetry in high energy astronomy; 3. Photoelectric polarimeters; 4. Bragg crystal polarimeters; 5. X-ray polarimetry with the photon counting pixel detector timepix; 6. HE polarized photon interactions with matter: simulations with geant4; 7. The GPD as a polarimeter: theory and facts; 8. Ideal gas electron multipliers (GEMs) for x-ray polarimeters; 9. Broad-band soft x-ray polarimetry; 10. Feasibility of x-ray photoelectric polarimeters with large field of view; 11. Angular resolution of a photoelectric polarimeter; 12. Development of a Thomson x-ray polarimeter; 13. Hard x / soft gamma ray polarimetry using a Laue lens; Part II. Polarized Emission in X-ray Sources: 14. Probing strong gravity effects with x-ray polarimetry; 15. X-ray polarization from black holes in the thermal state; 16. Strong-gravity effects acting on polarization from orbiting spots; 17. Polarization of thermal emission from accreting black holes; 18. X-ray polarimetry and radio-quiet AGN; 19. The soft x-ray polarization in obscured AGN; 20. The polarization of complex x-ray sources; 21. Polarization of Compton x-rays from jets in AGN; 22. Polarization of x-ray lines from galaxy clusters and elliptical galaxies; 23. Polarization characteristics of rotation-powered pulsars; 24. Polarized x-rays from magnetized neutron stars; 25. Polarization properties of x-ray millisecond pulsars; 26. X-ray polarization signatures of neutron stars; 27. Polarization from the oscillating magnetized accretion torus; 28. X-ray polarization from accreting white dwarfs and associated systems; 29. Polarization of pulsar wind nebulae; 30. X-ray polarization of gamma-ray bursts; 31. Central engine afterglow from GRBs and the polarization signature; 32. GRB afterglow polarimetry. Past, present and future; 33. Gamma-ray polarimetry with SPI; 34. INTEGRAL/IBIS observations of the Crab Nebula and GRB 041219A; 35. Fermi results on the origin of high energy emission in pulsars; 36. Diagnostics of the evolution of spiral galaxies in a cluster environment; Part III. Future Missions: 37. Gravity and extreme magnetism SMEX (GEMS); 38. Programs of x-ray polarimetry in Italy; 39. A polarimeter for IXO; 40. Polarimetry with ASTRO-H soft gamma-ray detector; 41. EXIST and its polarization sensitivity; 42. PoGOLite: a balloon-borne soft gamma-ray polarimeter; 43. Studies of neutron background rejection in the PoGOLite polarimeter; 44. Observing polarized x-rays with PoGOLite; 45. Pre-flight qualification tests of the PoGOLite detector system; 46. The gamma-ray polarimeter experiment (GRAPE) Balloon Payload; 47. POLAR: an instrument dedicated to GRB polarization measurement; 48. Polarisation detection capability of GRIPS; 49. X-ray and y-ray polarimetry small satellite mission polaris; 50. GAP aboard the solar powered sail mission; 51. Hard x-ray polarimeter for small satellite missions; 52. Performance of hard x-ray polarimeter: PHENEX; 53. GRB polarimetry with POET; Index.

  7. X-ray binaries

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Satellite X-ray experiments and ground-based programs aimed at observation of X-ray binaries are discussed. Experiments aboard OAO-3, OSO-8, Ariel 5, Uhuru, and Skylab are included along with rocket and ground-based observations. Major topics covered are: Her X-1, Cyg X-3, Cen X-3, Cyg X-1, the transient source A0620-00, other possible X-ray binaries, and plans and prospects for future observational programs.

  8. Widely Wavelength-Tunable Blue-Shifted Dispersive Waves for Broadband Visible Wavelength Generation in a Photonic Crystal Fiber Cladding

    NASA Astrophysics Data System (ADS)

    Yuan, Jin-Hui; Sang, Xin-Zhu; Yu, Chong-Xiu; Shen, Xiang-Wei; Wang, Kui-Ru; Yan, Bin-Bin; Han, Ying; Zhou, Gui-Yao; Hou, Lan-Tian

    2012-10-01

    Blue-shifted dispersive waves (DWs) are efficiently generated from the red-shifted solitons by coupling the 120 fs pulses into the fundamental mode of the multi-knots of a photonic crystal fiber cladding. When the femtosecond pulses at the wavelength of 825 nm and the average power of 300 mW are coupled into knots 1-3, the conversion efficiency ?DW of 32% and bandwidth BDW of 50 nm are obtained. The ultrashort pulses generated by the DWs can be tunable over the whole visible wavelength by adjusting the wavelengths of the pump pulses coupled into different knots. It can be believed that this widely wavelength-tunable ultrashort visible pulse source has important applications in ultrafast photonics and resonant Raman scattering.

  9. Quantitative Measurements of X-ray Intensity

    SciTech Connect

    Haugh, M. J., Schneider, M.

    2011-09-01

    This chapter describes the characterization of several X-ray sources and their use in calibrating different types of X-ray cameras at National Security Technologies, LLC (NSTec). The cameras are employed in experimental plasma studies at Lawrence Livermore National Laboratory (LLNL), including the National Ignition Facility (NIF). The sources provide X-rays in the energy range from several hundred eV to 110 keV. The key to this effort is measuring the X-ray beam intensity accurately and traceable to international standards. This is accomplished using photodiodes of several types that are calibrated using radioactive sources and a synchrotron source using methods and materials that are traceable to the U.S. National Institute of Standards and Technology (NIST). The accreditation procedures are described. The chapter begins with an introduction to the fundamental concepts of X-ray physics. The types of X-ray sources that are used for device calibration are described. The next section describes the photodiode types that are used for measuring X-ray intensity: power measuring photodiodes, energy dispersive photodiodes, and cameras comprising photodiodes as pixel elements. Following their description, the methods used to calibrate the primary detectors, the power measuring photodiodes and the energy dispersive photodiodes, as well as the method used to get traceability to international standards are described. The X-ray source beams can then be measured using the primary detectors. The final section then describes the use of the calibrated X-ray beams to calibrate X-ray cameras. Many of the references are web sites that provide databases, explanations of the data and how it was generated, and data calculations for specific cases. Several general reference books related to the major topics are included. Papers expanding some subjects are cited.

  10. The high energy X-ray universe

    PubMed Central

    Giacconi, Riccardo

    2010-01-01

    Since its beginning in the early 1960s, the field of X-ray astronomy has exploded, experiencing a ten-billion-fold increase in sensitivity, which brought it on par with the most advanced facilities at all wavelengths. I will briefly describe the revolutionary first discoveries prior to the launch of the Chandra and XMM-Newton X-ray observatories, present some of the current achievements, and offer some thoughts about the future of this field. PMID:20404148

  11. Fundamental physics with an X-ray free electron laser

    Microsoft Academic Search

    T. Tajima

    2003-01-01

    Of late, laboratories around the world are considering building X-ray free electron lasers based on high energy electron accelerators\\u000a (with energies exceeding 10 GeV) to produce bright coherent X rays with wavelengths on the order of 1 . Because of the extremely\\u000a small wavelength and high brilliance of these coherent X rays, there is an unprecedented opportunity to explore new

  12. X-ray astronomy

    Microsoft Academic Search

    R. Rocchia

    1984-01-01

    The observation of X-rays is a relatively new branch of Astronomy. As every new field of science this astronomy had an extremely fast and fruitful development. After twenty years of X ray exploration it is time to summarize the results and to envisage the future. This is the aim of this expose.After a brief review of the birth conditions of

  13. X-ray

    MedlinePLUS

    ... Most experts feel that the benefits of appropriate x-ray imaging greatly outweigh any risks. Young children and babies in the womb are more sensitive to the risks of x-rays. Tell your health care provider if you think ...

  14. High-intensity double-pulse X-ray free-electron laser

    NASA Astrophysics Data System (ADS)

    Marinelli, A.; Ratner, D.; Lutman, A. A.; Turner, J.; Welch, J.; Decker, F.-J.; Loos, H.; Behrens, C.; Gilevich, S.; Miahnahri, A. A.; Vetter, S.; Maxwell, T. J.; Ding, Y.; Coffee, R.; Wakatsuki, S.; Huang, Z.

    2015-03-01

    The X-ray free-electron laser has opened a new era for photon science, improving the X-ray brightness by ten orders of magnitude over previously available sources. Similar to an optical laser, the spectral and temporal structure of the radiation pulses can be tailored to the specific needs of many experiments by accurately manipulating the lasing medium, that is, the electron beam. Here we report the generation of mJ-level two-colour hard X-ray pulses of few femtoseconds duration with an XFEL driven by twin electron bunches at the Linac Coherent Light Source. This performance represents an improvement of over an order of magnitude in peak power over state-of-the-art two-colour XFELs. The unprecedented intensity and temporal coherence of this new two-colour X-ray free-electron laser enable an entirely new set of scientific applications, ranging from X-ray pump/X-ray probe experiments to the imaging of complex biological samples with multiple wavelength anomalous dispersion.

  15. High-intensity double-pulse X-ray free-electron laser.

    PubMed

    Marinelli, A; Ratner, D; Lutman, A A; Turner, J; Welch, J; Decker, F-J; Loos, H; Behrens, C; Gilevich, S; Miahnahri, A A; Vetter, S; Maxwell, T J; Ding, Y; Coffee, R; Wakatsuki, S; Huang, Z

    2015-01-01

    The X-ray free-electron laser has opened a new era for photon science, improving the X-ray brightness by ten orders of magnitude over previously available sources. Similar to an optical laser, the spectral and temporal structure of the radiation pulses can be tailored to the specific needs of many experiments by accurately manipulating the lasing medium, that is, the electron beam. Here we report the generation of mJ-level two-colour hard X-ray pulses of few femtoseconds duration with an XFEL driven by twin electron bunches at the Linac Coherent Light Source. This performance represents an improvement of over an order of magnitude in peak power over state-of-the-art two-colour XFELs. The unprecedented intensity and temporal coherence of this new two-colour X-ray free-electron laser enable an entirely new set of scientific applications, ranging from X-ray pump/X-ray probe experiments to the imaging of complex biological samples with multiple wavelength anomalous dispersion. PMID:25744344

  16. High-intensity double-pulse X-ray free-electron laser

    PubMed Central

    Marinelli, A.; Ratner, D.; Lutman, A. A.; Turner, J.; Welch, J.; Decker, F.-J.; Loos, H.; Behrens, C.; Gilevich, S.; Miahnahri, A. A.; Vetter, S.; Maxwell, T.J.; Ding, Y.; Coffee, R.; Wakatsuki, S.; Huang, Z.

    2015-01-01

    The X-ray free-electron laser has opened a new era for photon science, improving the X-ray brightness by ten orders of magnitude over previously available sources. Similar to an optical laser, the spectral and temporal structure of the radiation pulses can be tailored to the specific needs of many experiments by accurately manipulating the lasing medium, that is, the electron beam. Here we report the generation of mJ-level two-colour hard X-ray pulses of few femtoseconds duration with an XFEL driven by twin electron bunches at the Linac Coherent Light Source. This performance represents an improvement of over an order of magnitude in peak power over state-of-the-art two-colour XFELs. The unprecedented intensity and temporal coherence of this new two-colour X-ray free-electron laser enable an entirely new set of scientific applications, ranging from X-ray pump/X-ray probe experiments to the imaging of complex biological samples with multiple wavelength anomalous dispersion. PMID:25744344

  17. Detection of x ray sources in PROS

    NASA Technical Reports Server (NTRS)

    Deponte, J.; Primini, F. A.

    1992-01-01

    The problem of detecting discrete sources in x-ray images has much in common with the problem of automatic source detection at other wavelengths. In all cases, one searches for positive brightness enhancements exceeding a certain threshold, which appear consistent with what one expects for a point source, in the presence of a (possibly) spatially variable background. Multidimensional point spread functions (e.g., dependent on detector position and photon energy) are also common. At the same time, the problem in x-ray astronomy has some unique aspects. For example, for typical x-ray exposures in current or recent observatories, the number of available pixels far exceeds the number of actual x-ray events, so Poisson, rather than Gaussian statistics apply. Further, extended cosmic x-ray sources are common, and one often desires to detect point sources in the vicinity or even within bright, diffuse x-ray emission. Finally, support structures in x-ray detectors often cast sharp shadows in x-ray images making it necessary to detect sources in a region of rapidly varying exposure. We have developed a source detection package within the IRAF/PROS environment which attempts to deal with some of the problems of x-ray source detection. We have patterned our package after the successful Einstein Observatory x-ray source detection programs. However, we have attempted to improve the flexibility and accessibility of the functions and to provide a graphical front-end for the user. Our philosophy has been to use standard IRAF tasks whenever possible for image manipulation and to separate general functions from mission-specific ones. We will report on the current status of the package and discuss future developments, including simulation tasks, to allow the user to assess detection efficiency and source significance, tasks to determine source intensity, and alternative detection algorithms.

  18. Bright and dark pulses in optical fibres in the vicinity of the zero-dispersion wavelength

    SciTech Connect

    Molotkov, I A [Institute of Earth Magnetism, Ionosphere and Propagation of Radio waves, Russian Academy of Sciences, Moscow (Russian Federation); Bisyarin, M A [St. Petersburg State University, Research Institute of Radiophysics (Russian Federation)

    2004-02-28

    The influence of the third-order dispersion on the propagation of short pulses in optical fibres is considered. The appearance of coupled nonlinear structures consisting of dark and bright envelope solitons is described. The wavelength range is found in the vicinity of the zero-dispersion wavelength where the effect of the third-order dispersion on the pulse propagation proves to be dominant. It is shown that in this case a nonlinear structure in the form of an embedded soliton appears. (solitons)

  19. Determination and speciation of trace and ultratrace selenium ions by energy-dispersive X-ray fluorescence spectrometry using graphene as solid adsorbent in dispersive micro-solid phase extraction.

    PubMed

    Kocot, Karina; Leardi, Riccardo; Walczak, Beata; Sitko, Rafal

    2015-03-01

    A dispersive micro-solid phase extraction (DMSPE) with graphene as a solid adsorbent and ammonium pyrrolidinedithiocarbamate (APDC) as a chelating agent was proposed for speciation and detemination of inorganic selenium by the energy-dispersive X-ray fluorescence spectrometry (EDXRF). In developed DMSPE, graphene particles are dispersed throughout the analyzed solution, therefore reaction between Se(IV)-APDC complexes and graphene nanoparticles occurs immediately. The concentration of Se(VI) is calculated as the difference between the concentration of selenite after and before prereduction of selenate. A central composite face-centered design with 3 center points was performed in order to optimize conditions and to study the effect of four variables (pH of the sample, concentration of APDC, concentration of Triton-X-100, and sample volume). The best results were obtained when suspension consisting of 200µg of graphene nanosheets, 1.2mg of APDC and 0.06mg of Triton-X-100 was rapidly injected to the 50mL of the analyzed solution. Under optimized conditions Se ions can be determined with a very good recovery (97.7±5.0% and 99.2±6.6% for Se(IV) and Se(VI), respectively) and precision (RSD=5.1-6.6%). Proposed DMSPE/EDXRF procedure allowed to obtain low detection limits (0.032ngmL(-1)) and high enrichment factor (1013±15). The proposed methodology was successfully applied for the determination of Se in mineral, tap, lake and sea water samples as well as in biological materials (Lobster Hepatopancreas and Pig Kidney). PMID:25618680

  20. Thoracic spine x-ray

    MedlinePLUS

    Vertebral radiography; X-ray - spine; Thoracic x-ray; Spine x-ray; Thoracic spine films; Back films ... The test is done in a hospital radiology department or in the health care provider's office. You will lie on the x-ray table in different positions. If the x-ray ...

  1. Opportunities for resonant elastic X-ray scattering at X-ray free-electron lasers

    NASA Astrophysics Data System (ADS)

    Altarelli, M.

    2012-06-01

    X-ray Free-Electron Lasers (FELs) are beginning to deliver a revolution in X-ray experiments, thanks to their ultra-bright (peak brightness exceeding 1033 photons/s/mm2/mrad2/0.1%BW), ultrashort (down to a few fs), spatially coherent X-ray pulses. Presently operational facilities cover wide spectral ranges, from the VUV and soft X-ray wavelengths of FLASH in Hamburg (down to 4.2 nm), to the hard X-rays delivered by the LCLS in Stanford (wavelengths of 0.15 nm or shorter). The basic properties of the new sources are briefly reviewed, and the impact on resonant scattering experiments is discussed. The perspective of investigating ultrafast magnetism, and, more generally, the time-dependent response of strongly correlated electron systems, in a pump-and-probe mode at the L edges of 3d transition metals, would be very attractive. In the hard X-ray range, the very recent proposal of self-seeded X-ray FELs, with 10-5 intrinsic bandwidth, tunable wavelength, 100 fs pulses and number of photons per pulse of order 1012 also opens exciting possibilities for resonant scattering.

  2. A single-pass free-electron laser for soft x-rays with wavelengths less than or equal to 10 nm

    SciTech Connect

    Goldstein, J.C.; Wang, T.F.; Newnam, B.E.; McVey, B.D.

    1987-01-01

    We consider a single-pass FEL amplifier, driven by an rf-linac followed by a damping ring for reduced emittance, for use in generating intense coherent light at wavelengths <10 nm. The dependence of the optical gain on electron beam quality, studied with the 3-D FEL simulation code FELEX, is given and related to the expected power of self-amplified spontaneous emission. Design issues for the damping ring to achieve the required electron beam quality are discussed.

  3. X-ray Fluorescence Determination of Element Contents in Milk and Dairy Products

    Microsoft Academic Search

    Galina V. Pashkova

    2009-01-01

    The concentrations of minerals (Na, Mg, P, S, Cl, K, and Ca) and trace elements (Mn, Fe, Ni, Cu, Zn, Rb, Sr, and Br) in different\\u000a types of milk, dairy products, and infant formulas have been determined using wavelength-dispersive X-ray fluorescence analysis\\u000a (WDXRF). Freeze-dried samples pressed as tablets of 4 g have been analyzed. Calibrations have been established using both\\u000a plant

  4. Electron and proton induced x-ray spectrometry: Two complementary spatially resolved analytical techniques in mineralogy

    Microsoft Academic Search

    G. Remond; C. Gilles; D. Isabelle; C. Choi; M. Azahra; O. Rouer; F. Cesbron

    1995-01-01

    Spatially resolved quantitative analysis by means of the electron probe micro analyzer (EPMA) is now well-established as a routine analytical method for point chemical analysis of a variety of mineral materials. Modern computer controlled EPMA are most often equipped with wavelength dispersive spectrometers (WDS). Quantitative analysis are generally carried out according to a standard based approached, i.e. the x-ray intensities

  5. Normal incidence x-ray mirror for chemical microanalysis

    DOEpatents

    Carr, M.J.; Romig, A.D. Jr.

    1987-08-05

    An x-ray mirror for both electron column instruments and micro x-ray fluorescence instruments for making chemical, microanalysis comprises a non-planar mirror having, for example, a spherical reflecting surface for x-rays comprised of a predetermined number of alternating layers of high atomic number material and low atomic number material contiguously formed on a substrate and whose layers have a thickness which is a multiple of the wavelength being reflected. For electron column instruments, the wavelengths of interest lie above 1.5nm, while for x-ray fluorescence instruments, the range of interest is below 0.2nm. 4 figs.

  6. Coherent x-ray lasers for applications

    SciTech Connect

    London, R.A.; Amendt, P.; Rosen, M.D.; Feit, M.D.; Fleck, J.A. (Lawrence Livermore National Lab., CA (USA)); Strauss, M. (Negev Nuclear Research Centre, Beersheba (Israel))

    1990-12-01

    Many of the projected applications of x-ray lasers require high quality output radiation with properties such as short wavelength, high power, good focusability, short pulse, and high degree of coherence. We discuss the requirements of an x-ray laser for the application of holography of biological samples. We present ideas for achieving these properties. Given that population inversions can be established to provide laser gain, we discuss how the propagation and amplification of x-rays within the lasing medium affect the quality of the output radiation. Particular attention is given toward the development of transverse coherence. Results are presented from several methods for calculating the coherence, including a modal analysis and a numerical-wave propagation code. Calculations of the expected degree of coherence of standard x-ray lasers are given, as well as designs for more coherent lasers. 9 refs., 6 figs., 1 tab.

  7. X-Ray Background Survey Spectrometer (XBSS)

    NASA Technical Reports Server (NTRS)

    Sanders, W. T. (Principal Investigator); Paulos, R. J.

    1996-01-01

    The objective of this investigation was to perform a spectral survey of the low energy diffuse X-ray background using the X-ray Background Survey Spectrometer (XBSS) on board the Space Station Freedom (SSF). XBSS obtains spectra of the X-ray diffuse background in the 11-24 A and 44-84 A wavelength intervals over the entire sky with 15 deg spatial resolution. These X-rays are almost certainly from a very hot (10(exp 6) K) component of the interstellar medium that is contained in regions occupying a large fraction of the interstellar volume near the Sun. Astrophysical plasmas near 10(exp 6) K are rich in emission lines, and the relative strengths of these lines, besides providing information about the physical conditions of the emitting gas, also provide information about its history and heating mechanisms.

  8. Understanding X-ray super-saturation

    NASA Astrophysics Data System (ADS)

    Hussain, Gaitee

    2006-09-01

    X-ray emission is commonly used to measure magnetic activity in cool stars. While X-ray levels and magnetic activity levels rise with stellar rotation rate, X-ray luminosities actually decline or "super-saturate" in the most rapidly rotating stars. Conflicting theories have been used to explain this: e.g., magnetic dynamos are inhibited, surface fields are more confined or their heating is less efficient, or emission is reduced due to centrifugal stripping of the outer corona. We will test different explanations of super-saturation through a multi-wavelength study of the star, AP 139. By comparing rotational modulation in its X-ray lightcurves and temperatures with maps of surface activity we can learn if and how this phenomenon is related to changes in the star's surface fields.

  9. Panoramic Dental X-Ray

    MedlinePLUS

    ... x-rays. top of page What does the equipment look like? A panoramic x-ray machine consists ... current x-ray images for diagnosis and disease management. The digital format also allows the dentist to ...

  10. Proposal for highly residual dispersion compensating defected core decagonal photonic crystal fiber over S+C+L+U wavelength bands

    NASA Astrophysics Data System (ADS)

    Islam, Md. Aminul; Ahmad, Redwan; Ali, Md. Sharafat; Nasim, K. M.

    2014-07-01

    A defected core decagonal photonic crystal fiber is designed and numerically optimized to obtain its residual chromatic dispersion compensation in the wavelength range of 1460 to 1675 nm i.e., over S+C+L+U wavelength bands having an average dispersion of about -390 ps/(nm km) with a dispersion variation of 7 ps/(nm km). The designed fiber, with a flattened dispersion profile, has four rings of holes in the cladding region, which results in low confinement loss and small effective mode area at wavelength 1550 nm. For residual chromatic dispersion compensation, the proposed fiber can be used in wavelength division multiplexing optical fiber data communication systems.

  11. Programmed cell death: Cytochemical and X-ray microanalytical characterization of calcium compartments in neuromuscular junctions during the normal breakdown of the intersegmental muscles in the giant silkmoth Antheraea polyphemus

    Microsoft Academic Search

    Jacques Beaulaton; Universitd Blaise

    1988-01-01

    Summary  Calcium stores were cytochemically demonstrated using a combined oxalate—pyroantimonate method in the neuromuscular junctions of the degenerating intersegmental muscles in the giant silkmothAntheraea polyphemus. The elemental composition of punctate precipitates of the reaction product was determined by electron probe X-ray microanalysis of unstained thin sections by energy-dispersive spectrometry and wavelength-dispersive spectrometry. The wavelength-dispersive spectra collected over terminal axons demonstrate a

  12. X-Ray Diffraction.

    ERIC Educational Resources Information Center

    Smith, D. K.; Smith, K. L.

    1980-01-01

    Reviews applications in research and analytical characterization of compounds and materials in the field of X-ray diffraction, emphasizing new developments in applications and instrumentation in both single crystal and powder diffraction. Cites 414 references. (CS)

  13. X-Ray Diffraction

    NSDL National Science Digital Library

    Matter.org

    This site from the University of London presents a tutorial on several methods of X-ray diffraction, including the powder, rotating crystal, and Laue methods Each section includes interactive Java applets, exercises, and links to a glossary of terms.

  14. Characterization of toners and inkjets by laser ablation spectrochemical methods and Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy

    NASA Astrophysics Data System (ADS)

    Trejos, Tatiana; Corzo, Ruthmara; Subedi, Kiran; Almirall, José

    2014-02-01

    Detection and sourcing of counterfeit currency, examination of counterfeit security documents and determination of authenticity of medical records are examples of common forensic document investigations. In these cases, the physical and chemical composition of the ink entries can provide important information for the assessment of the authenticity of the document or for making inferences about common source. Previous results reported by our group have demonstrated that elemental analysis, using either Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) or Laser Ablation Induced Breakdown Spectroscopy (LIBS), provides an effective, practical and robust technique for the discrimination of document substrates and writing inks with minimal damage to the document. In this study, laser-based methods and Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy (SEM-EDS) methods were developed, optimized and validated for the forensic analysis of more complex inks such as toners and inkjets, to determine if their elemental composition can differentiate documents printed from different sources and to associate documents that originated from the same printing source. Comparison of the performance of each of these methods is presented, including the analytical figures of merit, discrimination capability and error rates. Different calibration strategies resulting in semi-quantitative and qualitative analysis, comparison methods (match criteria) and data analysis and interpretation tools were also developed. A total of 27 black laser toners originating from different manufacturing sources and/or batches were examined to evaluate the discrimination capability of each method. The results suggest that SEM-EDS offers relatively poor discrimination capability for this set (~ 70.7% discrimination of all the possible comparison pairs or a 29.3% type II error rate). Nonetheless, SEM-EDS can still be used as a complementary method of analysis since it has the advantage of being non-destructive to the sample in addition to providing imaging capabilities to further characterize toner samples by their particle morphology. Laser sampling methods resulted in an improvement of the discrimination between different sources with LIBS producing 89% discrimination and LA-ICP-MS resulting in 100% discrimination. In addition, a set of 21 black inkjet samples was examined by each method. The results show that SEM-EDS is not appropriate for inkjet examinations since their elemental composition is typically below the detection capabilities with only sulfur detected in this set, providing only 47.4% discrimination between possible comparison pairs. Laser sampling methods were shown to provide discrimination greater than 94% for this same inkjet set with false exclusion and false inclusion rates lower than 4.1% and 5.7%, for LA-ICP-MS and LIBS respectively. Overall these results confirmed the utility of the examination of printed documents by laser-based micro-spectrochemical methods. SEM-EDS analysis of toners produced a limited utility for discrimination within sources but was not an effective tool for inkjet ink discrimination. Both LA-ICP-MS and LIBS can be used in forensic laboratories to chemically characterize inks on documents and to complement the information obtained by conventional methods and enhance their evidential value.

  15. Cosmic x ray physics

    NASA Technical Reports Server (NTRS)

    Mccammon, Dan; Cox, D. P.; Kraushaar, W. L.; Sanders, W. T.

    1992-01-01

    This final report covers the period 1 January 1985 - 31 March 1992. It is divided into the following sections: the soft x-ray background; proportional counter and filter calibrations; sounding rocket flight preparations; new sounding rocket payload: x-ray calorimeter; and theoretical studies. Staff, publications, conference proceedings, invited talks, contributed talks, colloquia and seminars, public service lectures, and Ph. D. theses are listed.

  16. 5.8 X-ray Calorimeters

    NASA Technical Reports Server (NTRS)

    Porter, F. Scott

    2008-01-01

    X-ray calorimeter instruments for astrophysics have seen rapid development since they were invented in 1984. The prime instrument on all currently planned X-ray spectroscopic observatories is based on calorimeter technology. This relatively simple detection concept that senses the energy of an incident photon by measuring the temperature rise of an absorber material at very low temperatures, can form the basis of a very high performance, non-dispersive spectrometer. State-of-the-art calorimeter instruments have resolving powers of over 3000, large simultaneous band-passes, and near unit efficiency. This coupled with the intrinsic imaging capability of a pixilated x-ray calorimeter array, allows true spectral-spatial instruments to be constructed. In this chapter I briefly review the detection scheme, the state-of-the-art in X-ray calorimeter instruments and the future outlook for this technology.

  17. In-situ synchrotron energy-dispersive x-ray diffraction study of thin Pd foils with Pd:D and Pd:H concentrations up to 1:1

    NASA Astrophysics Data System (ADS)

    Knies, D. L.; Violante, V.; Grabowski, K. S.; Hu, J. Z.; Dominguez, D. D.; He, J. H.; Qadri, S. B.; Hubler, G. K.

    2012-10-01

    Time resolved, in-situ, energy dispersive x-ray diffraction was performed in an electrolysis cell during electrochemical loading of palladium foil cathodes with hydrogen and deuterium. Concentrations of H:Pd (D:Pd) up to 1:1 in 0.1 M LiOH (LiOD) in H2O (D2O) electrolyte were obtained, as determined by both the Pd lattice parameter and cathode resistivity. In addition, some indications on the kinetics of loading and deloading of hydrogen from the Pd surface were obtained. The alpha-beta phase transformations were clearly delineated but no new phases at high concentration were determined.

  18. Atomic ordering in Cax\\/2AlxSi1-xO2 glasses (x=0,0.34,0.5,0.68) by energy-dispersive x-ray diffraction

    Microsoft Academic Search

    V. Petkov; Th. Gerber; B. Himmel

    1998-01-01

    Extended structure factors for Cax\\/2AlxSi1-xO2 glasses (x=0,0.34,0.5,0.68) have been obtained by energy-dispersive x-ray diffraction. The first neighbor Si-O and Al-O interatomic distances and coordination numbers have been determined thanks to the improved resolution of the experimental atomic distribution functions. It has been found that Al atoms are always fourfold coordinated by oxygen atoms while the oxygen coordination of Si atoms

  19. X-ray wavelengths and Auger transition energies of 1s 2p4 (2S, 2,4P, 2D) resonances in B-like (Z = 6–18) ions

    NASA Astrophysics Data System (ADS)

    Sakho, I.; Sow, M.; Wagué, A.

    2015-04-01

    We report Auger energies of the 1s 2p4 (2S, 2,4P, 2D) resonances belonging to the 1s 2p4 (2S, 2,4P, 2D) ? 1s2 2p2 (1S, 1P, 1D) and to the 1s 2p4 (2S, 2,4P, 2D) ? 1s2 2s2p 1,3P transitions in B-like ions (Z = 6–18). X-ray wavelengths of the 1s2p4 (2S, 2P, 2D) resonances are also reported. The calculations are carried out in the framework of the screening constant by unit nuclear charge (SCUNC) formalism. The present results for the core-excited 1s 2p4 (2S, 2,4P, 2D) resonances in B-like C+, O3+, Ne5+, Mg7+ and Si9+ ions agree well with recent saddle-point variation and saddle-point complex-rotation (SPCR) results (Sun et al 2013 Phys. Rev A 87 032509). The new Auger energies and wavelengths for the 1s 2p4 (2S, 2,4P, 2D) resonances in B-like N2+, F4+, Na6+, Al8+, P10+, S11+, Cl12+ and Ar13+ ions provide benchmarked values for future experimental and theoretical studies on these B-like ions in connection with the diagnostic of astrophysical and laboratory plasma.

  20. Principles of X-ray Navigation

    SciTech Connect

    Hanson, John Eric; /SLAC

    2006-03-17

    X-ray navigation is a new concept in satellite navigation in which orientation, position and time are measured by observing stellar emissions in x-ray wavelengths. X-ray navigation offers the opportunity for a single instrument to be used to measure these parameters autonomously. Furthermore, this concept is not limited to missions in close proximity to the earth. X-ray navigation can be used on a variety of missions from satellites in low earth orbit to spacecraft on interplanetary missions. In 1997 the Unconventional Stellar Aspect Experiment (USA) will be launched as part of the Advanced Research and Global Observation Satellite (ARGOS). USA will provide the first platform for real-time experimentation in the field of x-ray navigation and also serves as an excellent case study for the design and manufacturing of space qualified systems in small, autonomous groups. Current techniques for determining the orientation of a satellite rely on observations of the earth, sun and stars in infrared, visible or ultraviolet wavelengths. It is possible to use x-ray imaging devices to provide arcsecond level measurement of attitude based on star patterns in the x-ray sky. This technique is explored with a simple simulation. Collimated x-ray detectors can be used on spinning satellites to provide a cheap and reliable measure of orientation. This is demonstrated using observations of the Crab Pulsar taken by the high Energy Astronomy Observatory (HEAO-1) in 1977. A single instrument concept is shown to be effective, but dependent on an a priori estimate of the guide star intensity and thus susceptible to errors in that estimate. A star scanner based on a differential measurement from two x-ray detectors eliminates the need for an a priori estimate of the guide star intensity. A first order model and a second order model of the two star scanner concepts are considered. Many of the stars that emit in the x-ray regime are also x-ray pulsars with frequency stability approaching a part in 10{sup 9}. By observing these pulsations, a satellite can keep accurate time autonomously. They have demonstrated the acquisition and tracking of the Crab nebula pulsar by simulating the operation of a phase-locked loop.

  1. Nonlinear wavelength conversion in photonic crystal fibers with three zero-dispersion points

    SciTech Connect

    Stark, S. P.; Biancalana, F.; Podlipensky, A.; St. J. Russell, P. [Max Planck Institute for the Science of Light Guenther-Scharowsky Str. 1/Bau 24, D-91058 Erlangen (Germany)

    2011-02-15

    In this theoretical study, we show that a simple endlessly single-mode photonic crystal fiber can be designed to yield, not just two, but three zero-dispersion wavelengths. The presence of a third dispersion zero creates a rich phase-matching topology, enabling enhanced control over the spectral locations of the four-wave-mixing and resonant-radiation bands emitted by solitons and short pulses. The greatly enhanced flexibility in the positioning of these bands has applications in wavelength conversion, supercontinuum generation, and pair-photon sources for quantum optics.

  2. Multilayer mirror technology for soft-x-ray projection lithography

    Microsoft Academic Search

    D. G. Stearns; R. S. Rosen; S. P. Vernon

    1993-01-01

    Recent advances in multilayer mirror technology meet many of the stringent demands of soft-x-ray projection lithography (SXPL). The maximum normal-incidence reflectivity achieved to date is 66% for Mo\\/Si multilayers at a soft-x-ray wavelength of 13.4 nm, which is sufficient to satisfy the x-ray throughput requirements of SXPL. These high-performance coatings can be deposited on figured optics with layer thickness control

  3. Extragalactic X-ray surveys of ULXs and AGNs

    Microsoft Academic Search

    Lisa M. Winter

    2008-01-01

    Extragalactic X-ray studies provide unique opportunities for studying accreting black holes. In particular, they are necessary for studying phenomena not easily selected or observed in other wavelengths. Among these objects, ultraluminous X-ray sources (ULXs) emit the vast majority of their luminosity in the X-ray band and are very faint or confused in other wavebands. Similarly, heavily obscured active galactic nuclei

  4. Dispersion measurement of optical fiber using dual wavelength diffraction phase microscope

    NASA Astrophysics Data System (ADS)

    Jafarfard, Mohammad Reza; Tayebi, Behnam; Nasab, Razie Jalai; Kim, Dug Young

    2014-11-01

    Various quantitative phase microscopy (QPM) techniques for noninvasive and quantitative analysis of samples proposed based on imaging interferometry techniques over the last decade [1-4]. A phase image can be obtained with a single set of interference data in some types of phase microscopes such as diffraction phase microscope [5, 6]. They are suitable for studying rapidly varying phenomena with reduced concern for systematic and sample variations that may occur during the acquisition of the raw data. Dispersion measurements of a sample carry more information than refractive index of measurements at a single wavelength [7]. Knowledge of the optical dispersion for phase objects such as optical fibers, biological cells and micro-particles can provide very useful information about their property. In this work, we report on a common-path and dual wavelength quantitative phase microscope that simultaneously acquires two phase images at different wavelengths. The simultaneous dual-wavelength measurement was performed with a diffraction phase microscope based on a transmission grating and a spatial filter that form a common-path imaging interferometer. With a combined laser source that generates two-color light continuously, a different diffraction order of the grating was utilized for each wavelength component so that the dual-wavelength interference pattern could be distinguished by the distinct fringe frequencies. The refractive index profiles of fiber in both wavelengths were measured adequately by our DW-DPM system.

  5. Compton backscattered collmated X-ray source

    DOEpatents

    Ruth, Ronald D. (Woodside, CA); Huang, Zhirong (Stanford, CA)

    2000-01-01

    A high-intensity, inexpensive and collimated x-ray source for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications.

  6. Compton backscattered collimated x-ray source

    DOEpatents

    Ruth, Ronald D. (Woodside, CA); Huang, Zhirong (Stanford, CA)

    1998-01-01

    A high-intensity, inexpensive and collimated x-ray source for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications.

  7. X-ray laser driven gold targets

    SciTech Connect

    Petrova, Tz. B., E-mail: lina.petrova@nrl.navy.mil; Whitney, K. G.; Davis, J. [Plasma Physics Division, Naval Research Laboratory, 4555 Overlook Ave. SW, Washington, DC 20375 (United States)] [Plasma Physics Division, Naval Research Laboratory, 4555 Overlook Ave. SW, Washington, DC 20375 (United States)

    2014-03-15

    The femtosecond population dynamics of gold irradiated by a coherent high-intensity (>10{sup 17}?W/cm{sup 2}) x-ray laser pulse is investigated theoretically. There are two aspects to the assembled model. One is the construction of a detailed model of platinum-like gold inclusive of all inner-shell states that are created by photoionization of atomic gold and decay either by radiative or Auger processes. Second is the computation of the population dynamics that ensues when an x-ray pulse is absorbed in gold. The hole state generation depends on the intensity and wavelength of the driving x-ray pulse. The excited state populations reached during a few femtosecond timescales are high enough to generate population inversions, whose gain coefficients are calculated. These amplified lines in the emitted x-ray spectrum provide important diagnostics of the radiation dynamics and also suggest a nonlinear way to increase the frequency of the coherent output x-ray pulses relative to the frequency of the driver input x-ray pulse.

  8. Compton backscattered collimated x-ray source

    DOEpatents

    Ruth, R.D.; Huang, Z.

    1998-10-20

    A high-intensity, inexpensive and collimated x-ray source is disclosed for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications. 4 figs.

  9. X-Rays for Children

    MedlinePLUS

    ... is useful when the dentist does not have a panoramic X-ray machine or when the child has difficulty in taking bitewing or periapical X-rays. Orthodontic X-rays (also called cephalometric or lateral skull) — This type of X-ray shows the head from the side. It is used to evaluate growth of the jaws ...

  10. Lumbosacral spine x-ray

    MedlinePLUS

    X-ray - lumbosacral spine; X-ray - lower spine ... be placed over the lower part of your spine. You will be asked to hold your breath ... x-ray. The most common reason for lumbosacral spine x-ray is to look for the cause ...

  11. Direct chlorine determination in crude oils by energy dispersive X-ray fluorescence spectrometry: An improved method based on a proper strategy for sample homogenization and calibration with inorganic standards

    NASA Astrophysics Data System (ADS)

    Doyle, Adriana; Saavedra, Alvaro; Tristão, Maria Luiza B.; Nele, Márcio; Aucélio, Ricardo Q.

    2011-05-01

    Official guidelines to perform chlorine determination in crude oil are (i) American Society for Testing and Materials (ASTM) D6470, which is based on the extraction of water from the oil and subsequent determination of the chloride by potentiometry, (ii) ASTM D3230, that measures the conductivity of a solution of crude oil in a mixture of organic solvents and (iii) US Environmental Protection Agency (EPA) 9075 that uses energy dispersive X-ray fluorescence spectrometry to quantify chlorine and it is applicable for the range from 200 ?g g - 1 to percent levels of the analyte. The goal of this work is to propose method to quantify lower amounts of chlorine in crude oil using energy dispersive X-ray fluorescence spectrometry using a simple calibration strategy. Sample homogenization procedure was carefully studied in order to enable accurate results. The calibration curve was made with standards prepared by diluting aqueous NaCl standard in glycerin. The method presented a linear response that covers the range from 8 to at least 100 ?g g - 1 of chlorine. Chlorine in crude oil samples from Campos Basin - Brazil were quantified by the proposed method and by potentiometry after extraction of chlorine from the oil. Results achieved using both methods were statistically the same at 95% confidence level.

  12. X-ray modulation transfer functions of photostimulable phosphor image plates and scanners

    SciTech Connect

    Seely, John F.; Holland, Glenn E.; Hudson, Lawrence T.; Henins, Albert

    2008-11-01

    The modulation transfer functions of two types of photostimulable phosphor image plates were determined in the 10 keV to 50 keV x-ray energy range using a resolution test pattern with up to 10 line pairs per mm (LP/mm) and a wavelength dispersive x-ray spectrometer. Techniques were developed for correcting for the partial transmittance of the high energy x rays through the lead bars of the resolution test pattern, and the modulation transfer function (MTF) was determined from the measured change in contrast with LP/mm values. The MTF was convolved with the slit function of the image plate scanner, and the resulting point spread functions (PSFs) were in good agreement with the observed shapes and widths of x-ray spectral lines and with the PSF derived from edge spread functions. The shapes and the full width at half-maximum (FWHM) values of the PSF curves of the Fuji Superior Resolution (SR) and Fuji Maximum Sensitivity (MS) image plate detectors, consisting of the image plate and the scanner, determined by the three methods gave consistent results: The SR PSF is Gaussian with 0.13 mm FWHM, and the MS PSF is Lorentzian with 0.19 mm FWHM. These techniques result in the accurate determination of the spatial resolution achievable using image plate and scanner combinations and enable the optimization of spatial resolution for x-ray spectroscopy and radiography.

  13. X-ray modulation transfer functions of photostimulable phosphor image plates and scanners.

    PubMed

    Seely, John F; Holland, Glenn E; Hudson, Lawrence T; Henins, Albert

    2008-11-01

    The modulation transfer functions of two types of photostimulable phosphor image plates were determined in the 10 keV to 50 keV x-ray energy range using a resolution test pattern with up to 10 line pairs per mm (LP/mm) and a wavelength dispersive x-ray spectrometer. Techniques were developed for correcting for the partial transmittance of the high energy x rays through the lead bars of the resolution test pattern, and the modulation transfer function (MTF) was determined from the measured change in contrast with LP/mm values. The MTF was convolved with the slit function of the image plate scanner, and the resulting point spread functions (PSFs) were in good agreement with the observed shapes and widths of x-ray spectral lines and with the PSF derived from edge spread functions. The shapes and the full width at half-maximum (FWHM) values of the PSF curves of the Fuji Superior Resolution (SR) and Fuji Maximum Sensitivity (MS) image plate detectors, consisting of the image plate and the scanner, determined by the three methods gave consistent results: The SR PSF is Gaussian with 0.13 mm FWHM, and the MS PSF is Lorentzian with 0.19 mm FWHM. These techniques result in the accurate determination of the spatial resolution achievable using image plate and scanner combinations and enable the optimization of spatial resolution for x-ray spectroscopy and radiography. PMID:19122716

  14. Study of a homogeneous X-ray selected AGN sample

    NASA Astrophysics Data System (ADS)

    Paronyan, Gurgen M.; Mickaelian, Areg M.; Abrahamyan, Hayk V.

    2014-07-01

    Based on optical identifications of ROSAT sources, we have created a large homogeneous catalog of X-ray selected AGN. The Hamburg-RASS Catalog (HRC) and Byurakan-Hamburg-RASS Catalog (BHRC) made up on the basis of optical identification of X-ray sources from ROSAT Bright Source (BSC) and Faint Source (FSC) catalogues, respectively, have been used. These identiifcations were based on low-dispersion spectra of Hamburg Quasar Survey (HQS). As a result, a new large sample of X-ray selected AGN has been compiled containing 4253 sources with photon count rate CR > 0.04 ct/s in the area with galactic latitudes |b|>20 and declinations ?>0. All these sources are classified as AGN or candidate AGN. We have carried out multiwavelength studies in several wavelength ranges (X-ray, optical, radio). Catalogues that more or less guarantee the completeness condition (all-sky or large area surveys) were used. A number of erroneous classifications were found (some AGN had been classified as stars or galaxies); 1024 and 59 from HRC and BHRC, respectively. Out of 4253 sources, 3352 are spectroscopically confirmed AGN (given in Veron-Cetty & Veron and Roma Blazar catalogs), and the rest 901 are candidate AGN. For 210 of them spectra are available in SDSS DR9, and the results of their classification are given in another paper. We calculated absolute magnitudes, fluxes, improved coordinates and redshifts. An attempt is made to find a connection between the radiation fluxes in different bands for different types of sources, and identify their typical characteristics, thus confirming candidate AGN and in some cases finding new ones.

  15. Advanced X-ray Astrophysics Facility (AXAF): An overview

    NASA Technical Reports Server (NTRS)

    Weisskopf, M. C.; ODell, S. L.; Elsner, R. F.; VanSpeybroeck, L. P.

    1995-01-01

    The Advanced X-ray Astrophysics Facility (AXAF) is the x-ray component of NASA's Great Observatories. To be launched in late 1998, AXAF will provide unprecedented capabilities for high-resolution imaging, spectrometric imaging, and high-resolution disperse spectroscopy, over the x-ray band from about 0.1 keV to 10 keV. With these capabilities, AXAF observations will address many of the outstanding questions in astronomy, astrophysics, and cosmology.

  16. Clocking Femtosecond X Rays

    NASA Astrophysics Data System (ADS)

    Cavalieri, A. L.; Fritz, D. M.; Lee, S. H.; Bucksbaum, P. H.; Reis, D. A.; Rudati, J.; Mills, D. M.; Fuoss, P. H.; Stephenson, G. B.; Kao, C. C.; Siddons, D. P.; Lowney, D. P.; Macphee, A. G.; Weinstein, D.; Falcone, R. W.; Pahl, R.; Als-Nielsen, J.; Blome, C.; Düsterer, S.; Ischebeck, R.; Schlarb, H.; Schulte-Schrepping, H.; Tschentscher, Th.; Schneider, J.; Hignette, O.; Sette, F.; Sokolowski-Tinten, K.; Chapman, H. N.; Lee, R. W.; Hansen, T. N.; Synnergren, O.; Larsson, J.; Techert, S.; Sheppard, J.; Wark, J. S.; Bergh, M.; Caleman, C.; Huldt, G.; van der Spoel, D.; Timneanu, N.; Hajdu, J.; Akre, R. A.; Bong, E.; Emma, P.; Krejcik, P.; Arthur, J.; Brennan, S.; Gaffney, K. J.; Lindenberg, A. M.; Luening, K.; Hastings, J. B.

    2005-03-01

    Linear-accelerator-based sources will revolutionize ultrafast x-ray science due to their unprecedented brightness and short pulse duration. However, time-resolved studies at the resolution of the x-ray pulse duration are hampered by the inability to precisely synchronize an external laser to the accelerator. At the Sub-Picosecond Pulse Source at the Stanford Linear-Accelerator Center we solved this problem by measuring the arrival time of each high energy electron bunch with electro-optic sampling. This measurement indirectly determined the arrival time of each x-ray pulse relative to an external pump laser pulse with a time resolution of better than 60 fs rms.

  17. X-ray Crystallography

    NSDL National Science Digital Library

    In this activity, by the Concord Consortium's Molecular Literacy project, students are introduced to the fundamental principles of X-ray crystallography and "guides students through a series of activities for learning how structural information can be derived from X-ray diffraction patterns." Upon completion of this activity students should be able to describe what can be detected with X-ray crystallography (proteins in particular) and explain the impact of temperature, atom size, and impurities in the test. The activity itself is a java-based interactive resource built upon the free, open source Molecular Workbench software. In the activity, students are allowed to explore at their own pace in a digital environment full of demonstrations, illustrations, and models they can manipulate. In addition to the activity, visitors will find an overview of the activity, a test and rubric, central concepts, and their correlation to AAAS standards.

  18. Tunable Monochromatic X-ray Source Based on Parametric X-ray Radiation at LEBRA, Nihon University

    SciTech Connect

    Hayakawa, Y.; Sato, I.; Hayakawa, K.; Tanaka, T.; Kuwada, T.; Sakai, T.; Nogami, K.; Nakao, K.; Inagaki, M. [Laboratory for Electron Beam Research and Application, Nihon University, Narashinodai 7-24-1, Funabashi 274-8501 (Japan); Mori, A. [College of Pharmacy, Nihon University, Funabashi 274-8555 (Japan)

    2007-01-19

    The monochromatic X-ray source based on parametric X-ray radiation (PXR) was developed by using the electron beam from the 125-MeV linac at Nihon University. The X-ray generating system consists of two silicon perfect-crystal plates to offer a wide tunability. The system has actually been providing the energy dispersive monochromatic X-ray beam in the region of 6 to 20 keV, using Si(111)-plane for the target and the second crystals. Since the X-ray beam from the PXR generator has rather high energy resolution and coherency, X-ray absorption fine structure (XAFS) measurement and phase-contrast imaging are possible applications of PXR. Actually, preliminary experiments on energy dispersive XAFS measurement and refraction-contrast imaging have been successfully carried out using the PXR beam.

  19. X-ray astronomical spectroscopy

    NASA Technical Reports Server (NTRS)

    Holt, Stephen S.

    1987-01-01

    The contributions of the Goddard group to the history of X-ray astronomy are numerous and varied. One role that the group has continued to play involves the pursuit of techniques for the measurement and interpretation of the X-ray spectra of cosmic sources. The latest development is the selection of the X-ray microcalorimeter for the Advanced X-ray Astrophysics Facility (AXAF) study payload. This technology is likely to revolutionize the study of cosmic X-ray spectra.

  20. X-ray microtomography

    SciTech Connect

    Landis, Eric N., E-mail: landis@maine.edu [Department of Civil and Environmental Engineering, University of Maine, 5711 Boardman Hall, Orono, Maine 04469 (United States); Keane, Denis T., E-mail: dtkeane@northwestern.edu [Department of Materials Science and Engineering, Northwestern University (United States); DND-CAT, Advanced Photon Source, Argonne National Laboratory, Bldg. 432/A002, 9700 S. Cass Ave, Argonne, Illinois 60439 (United States)

    2010-12-15

    In this tutorial, we describe X-ray microtomography as a technique to nondestructively characterize material microstructure in three dimensions at a micron level spatial resolution. While commercially available laboratory scale instrumentation is available, we focus our attention on synchrotron-based systems, where we can exploit a high flux, monochromatic X-ray beam to produce high fidelity three-dimensional images. A brief description of the physics and the mathematical analysis behind the technique is followed by example applications to specific materials characterization problems, with a particular focus on the utilization of three-dimensional image processing that can be used to extract a wide range of useful information.

  1. Highly efficient pulsed power supply system with a two-stage LC generator and a step-up transformer for fast capillary discharge soft x-ray laser at shorter wavelength

    SciTech Connect

    Sakai, Yusuke; Takahashi, Shnsuke; Komatsu, Takanori; Song, Inho; Watanabe, Masato; Hotta, Eiki [Department of Energy Sciences, Tokyo Institute of Technology, 4259-J2-35, Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan)

    2010-01-15

    Highly efficient and compact pulsed power supply system for a capillary discharge soft x-ray laser (SXRL) has been developed. The system consists of a 2.2 {mu}F two-stage LC inversion generator, a 2:54 step-up transformer, a 3 nF water capacitor, and a discharge section with a few tens of centimeter length capillary. Adoption of the pulsed transformer in combination with the LC inversion generator enables us to use only one gap switch in the circuit for charging the water capacitor up to about 0.5 MV. Furthermore, step-up ratio of a water capacitor voltage to a LC inversion generator initial charging voltage is about 40 with energy transfer efficiency of about 50%. It also leads to good reproducibility of a capillary discharge which is necessary for lasing a SXRL stably. For the study of the possibility of lasing a SXRL at shorter wavelength in a small laboratory scale, high-density and high-temperature plasma column suitable for the laser can be generated relatively easily with this system.

  2. X-RAY GROUPS OF GALAXIES IN THE AEGIS DEEP AND WIDE FIELDS

    SciTech Connect

    Erfanianfar, G.; Lerchster, M.; Nandra, K.; Connelly, J. L.; Mirkazemi, M. [Max Planck-Institute for Extraterrestrial Physics, P.O. Box 1312, Giessenbachstr. 1., D-85741 Garching (Germany); Finoguenov, A. [Department of Physics, University of Helsinki, Gustaf Haellstroemin katu 2a, FI-00014 Helsinki (Finland); Tanaka, M. [Institute for the Physics and Mathematics of the Universe, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8583 (Japan); Laird, E. [Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Bielby, R. [Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom); Faber, S. M.; Kocevski, D.; Jeltema, T. [UCO/Lick Observatories, Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Cooper, M. [Center for Galaxy Evolution, Department of Physics and Astronomy, University of California, Irvine, 4129 Frederick Reines Hall, Irvine, CA 92697 (United States); Newman, J. A. [Department of Physics and Astronomy, University of Pittsburgh, 401-C Allen Hall, 3941 O'Hara Street, Pittsburgh, PA 15260 (United States); Coil, A. L. [Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Drive, MC 0424, San Diego, CA 92093 (United States); Brimioulle, F. [University Observatory Munich, Ludwigs-Maximilians University Munich, Scheinerstr. 1, D-81679 Munich (Germany); Davis, M. [Department of Astronomy, University of California, Berkeley, Berkeley, CA 94720 (United States); McCracken, H. J. [Institut d'Astrophysique de Paris, UMR 7095 CNRS, Universite Pierre et Marie Curie, 98 bis boulevard Arago, F-75014 Paris (France); Willmer, C. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Gerke, B., E-mail: erfanian@mpe.mpg.de [Lawrence Berkeley National Laboratory, 1 Cyclotron Road MS 90R4000, Berkeley, CA 94720 (United States); and others

    2013-03-10

    We present the results of a search for extended X-ray sources and their corresponding galaxy groups from 800 ks Chandra coverage of the All-wavelength Extended Groth Strip International Survey (AEGIS). This yields one of the largest X-ray-selected galaxy group catalogs from a blind survey to date. The red-sequence technique and spectroscopic redshifts allow us to identify 100% of reliable sources, leading to a catalog of 52 galaxy groups. These groups span the redshift range z {approx} 0.066-1.544 and virial mass range M{sub 200} {approx} 1.34 Multiplication-Sign 10{sup 13}-1.33 Multiplication-Sign 10{sup 14} M{sub Sun }. For the 49 extended sources that lie within DEEP2 and DEEP3 Galaxy Redshift Survey coverage, we identify spectroscopic counterparts and determine velocity dispersions. We select member galaxies by applying different cuts along the line of sight or in projected spatial coordinates. A constant cut along the line of sight can cause a large scatter in scaling relations in low-mass or high-mass systems depending on the size of the cut. A velocity-dispersion-based virial radius can cause a larger overestimation of velocity dispersion in comparison to an X-ray-based virial radius for low-mass systems. There is no significant difference between these two radial cuts for more massive systems. Independent of radial cut, an overestimation of velocity dispersion can be created in the case of the existence of significant substructure and compactness in X-ray emission, which mostly occur in low-mass systems. We also present a comparison between X-ray galaxy groups and optical galaxy groups detected using the Voronoi-Delaunay method for DEEP2 data in this field.

  3. X-ray microanalysis in biomedical research

    Microsoft Academic Search

    G ROOMANS; Karl Zierold

    1989-01-01

    Many aspects of plant studies require knowledge on concentration s and distributions of elements with a good spatial resolution for an understanding of the uptake and transport of ions and their roles in metabolic processes and water relationships. Energy dispersive X-ray microanalysis is a powerful technique that allows the quantitative measurement of many elements of physiological interest at the subcellular

  4. X-Ray Transition Energies Database

    National Institute of Standards and Technology Data Gateway

    SRD 128 X-Ray Transition Energies Database (Web, free access)   This X-ray transition table provides the energies and wavelengths for the K and L transitions connecting energy levels having principal quantum numbers n = 1, 2, 3, and 4. The elements covered include Z = 10, neon to Z = 100, fermium. There are two unique features of this data base: (1) a serious attempt to have all experimental values on a scale consistent with the International System of measurement (the SI) and (2) inclusion of accurate theoretical estimates for all transitions.

  5. Pelvis x-ray

    MedlinePLUS

    The test is done in a radiology department or in the health care provider's office by an x-ray technician. You will lie down on the table. The pictures are then taken. You will change your body to other positions to provide ...

  6. X-ray imaging crystal spectrometer for extended X-ray sources

    DOEpatents

    Bitter, Manfred L. (Princeton, NJ); Fraenkel, Ben (Jerusalem, IL); Gorman, James L. (Bordentown, NJ); Hill, Kenneth W. (Lawrenceville, NJ); Roquemore, A. Lane (Cranbury, NJ); Stodiek, Wolfgang (Princeton, NJ); von Goeler, Schweickhard E. (Princeton, NJ)

    2001-01-01

    Spherically or toroidally curved, double focusing crystals are used in a spectrometer for X-ray diagnostics of an extended X-ray source such as a hot plasma produced in a tokomak fusion experiment to provide spatially and temporally resolved data on plasma parameters using the imaging properties for Bragg angles near 45. For a Bragg angle of 45.degree., the spherical crystal focuses a bundle of near parallel X-rays (the cross section of which is determined by the cross section of the crystal) from the plasma to a point on a detector, with parallel rays inclined to the main plain of diffraction focused to different points on the detector. Thus, it is possible to radially image the plasma X-ray emission in different wavelengths simultaneously with a single crystal.

  7. Multilayers for next-generation x-ray sources

    NASA Astrophysics Data System (ADS)

    Bajt, S.; Chapman, H. N.; Spiller, E.; Hau-Riege, S.; Alameda, J.; Nelson, A. J.; Walton, C. C.; Kjornrattanawanich, B.; Aquila, A.; Dollar, F.; Gullikson, E.; Tarrio, C.; Grantham, S.

    2007-05-01

    Multilayers are artificially layered structures that can be used to create optics and optical elements for a broad range of x-ray wavelengths, or can be optimized for other applications. The development of next generation x-ray sources (high brightness synchrotrons and x-ray free electron lasers) requires advances in x-ray optics. Newly developed multilayer-based mirrors and optical elements enabled efficient band-pass filtering, focusing and time resolved measurements in recent FLASH (Free Electron LASer in Hamburg) experiments. These experiments are providing invaluable feedback on the response of the multilayer structures to high intensity, short pulsed x-ray sources. This information is crucial to design optics for future x-ray free electron lasers and to benchmark computer codes that simulate damage processes.

  8. Quasi-monochromatic field-emission x-ray source

    SciTech Connect

    Diop, Babacar; Binh, Vu Thien [LPMCN, University of Lyon 1, Villeurbanne 69622 (France)

    2012-09-15

    By favoring the L-peak emission over the bremsstrahlung part, direct quasi-monochromatic soft x-ray emission has been obtained with a field emission (FE) x-ray source. The electron impact x-ray setup uses an arrayed cathode of carbon nanopearl FE tips as a stable cold electron source within a vacuum of 10{sup -6}-10{sup -7} Torr. The high brightness of the FE e-beam coupled with the array structure of the cold cathode allows a smoother control of the x-ray emission intensity. The wavelength of the x-ray source can be modified by the choice of target materials. Using Mo as the target material, the x-ray emission shows a peak centered at 2.45 keV with a monochromaticity between 75% and 55% and a FWHM in the range of 450 eV.

  9. X-ray free-electron lasers

    NASA Astrophysics Data System (ADS)

    Feldhaus, J.; Arthur, J.; Hastings, J. B.

    2005-05-01

    In a free-electron laser (FEL) the lasing medium is a high-energy beam of electrons flying with relativistic speed through a periodic magnetic field. The interaction between the synchrotron radiation that is produced and the electrons in the beam induces a periodic bunching of the electrons, greatly increasing the intensity of radiation produced at a particular wavelength. Depending only on a phase match between the electron energy and the magnetic period, the wavelength of the FEL radiation can be continuously tuned within a wide spectral range. The FEL concept can be adapted to produce radiation wavelengths from millimetres to Ångstroms, and can in principle produce hard x-ray beams with unprecedented peak brightness, exceeding that of the brightest synchrotron source by ten orders of magnitude or more. This paper focuses on short-wavelength FELs. It reviews the physics and characteristic properties of single-pass FELs, as well as current technical developments aiming for fully coherent x-ray radiation pulses with pulse durations in the 100 fs to 100 as range. First experimental results at wavelengths around 100 nm and examples of scientific applications planned on the new, emerging x-ray FEL facilities are presented.

  10. X-ray Free-electron Lasers

    SciTech Connect

    Feldhaus, J.; /DESY; Arthur, J.; Hastings, J.B.; /SLAC

    2007-02-23

    In a free-electron laser (FEL) the lasing medium is a high-energy beam of electrons flying with relativistic speed through a periodic magnetic field. The interaction between the synchrotron radiation that is produced and the electrons in the beam induces a periodic bunching of the electrons, greatly increasing the intensity of radiation produced at a particular wavelength. Depending only on a phase match between the electron energy and the magnetic period, the wavelength of the FEL radiation can be continuously tuned within a wide spectral range. The FEL concept can be adapted to produce radiation wavelengths from millimeters to Angstroms, and can in principle produce hard x-ray beams with unprecedented peak brightness, exceeding that of the brightest synchrotron source by ten orders of magnitude or more. This paper focuses on short-wavelength FELs. It reviews the physics and characteristic properties of single-pass FELs, as well as current technical developments aiming for fully coherent x-ray radiation pulses with pulse durations in the 100 fs to 100 as range. First experimental results at wavelengths around 100 nm and examples of scientific applications planned on the new, emerging x-ray FEL facilities are presented.

  11. Application of the X-ray fluorescence analysis and X-ray diffraction in geochemical studies of the Pleistocene tills from Holy Cross Mountains

    NASA Astrophysics Data System (ADS)

    Kubala-Kuku?, A.; Ludwikowska-K?dzia, M.; Bana?, D.; Braziewicz, J.; Majewska, U.; Pajek, M.; Wudarczyk-Mo?ko, J.

    2013-12-01

    X-ray fluorescence analysis methods (wavelength dispersive X-ray fluorescence analysis (WDXRF) and total reflection X-ray fluorescence (TXRF)) and X-ray powder diffraction (XRPD) have been applied in complementary geochemical studies of the Pleistocene till samples. The XRPD technique gave information about the mineral composition of the analyzed samples while the WDXRF and TXRF studies allowed the fast elemental analysis. The till samples were collected from different regions of Holy Cross Mountains (located in central Poland) which are still not unambiguously described in the context of the geochemical studies of the Quaternary sediments. The analysis was concentrated on the geochemical composition of the till samples both for materials occurring on the surface (characterized by continuous weathering processes) and for samples taken from core borehole. The overriding purpose of these studies is determination of the local lithotype of the tills and its lithologic and petrographic diagnostic properties, including the chemical composition of clay and minerals found in the clay. In the presented work the experimental sets up, sample preparation procedure and measurements programme will be discussed in details. Finally, the elemental and mineral compositions will be presented for studied different groups of the samples.

  12. Holography at x-ray wavelengths

    SciTech Connect

    Solem, T.C.; Baldwin, G.C.; Chapline, G.F.

    1981-01-01

    We discuss alternative holographic techniques for imaging microscopic structures with a short-pulse, high intensity, high-quantum-energy laser. We find that Fresnel transform holography using a photoresist for registration of the hologram is most likely to be within the scope of near term technology. Although it has advantages in time gating, using an in-line electron microscope for hologram registration has an unacceptable tradeoff between quantum efficiency and resolution. Fourier transform holography using a reflector to generate the reference beam might be a reasonable alternative using low resolution film, but is necessarily more complicated. We discuss the dependence of the required laser intensity on the resolution sought and on the elastic and absorption cross sections. We conclude that resonant scattering must be used to obtain holograms at reasonable intensities.

  13. X-ray lithography masking

    NASA Technical Reports Server (NTRS)

    Smith, Henry I. (Inventor); Lim, Michael (Inventor); Carter, James (Inventor); Schattenburg, Mark (Inventor)

    1998-01-01

    X-ray masking apparatus includes a frame having a supporting rim surrounding an x-ray transparent region, a thin membrane of hard inorganic x-ray transparent material attached at its periphery to the supporting rim covering the x-ray transparent region and a layer of x-ray opaque material on the thin membrane inside the x-ray transparent region arranged in a pattern to selectively transmit x-ray energy entering the x-ray transparent region through the membrane to a predetermined image plane separated from the layer by the thin membrane. A method of making the masking apparatus includes depositing back and front layers of hard inorganic x-ray transparent material on front and back surfaces of a substrate, depositing back and front layers of reinforcing material on the back and front layers, respectively, of the hard inorganic x-ray transparent material, removing the material including at least a portion of the substrate and the back layers of an inside region adjacent to the front layer of hard inorganic x-ray transparent material, removing a portion of the front layer of reinforcing material opposite the inside region to expose the surface of the front layer of hard inorganic x-ray transparent material separated from the inside region by the latter front layer, and depositing a layer of x-ray opaque material on the surface of the latter front layer adjacent to the inside region.

  14. Nonlinear X-ray Compton Scattering

    E-print Network

    Fuchs, Matthias; Chen, Jian; Ghimire, Shambhu; Shwartz, Sharon; Kozina, Michael; Jiang, Mason; Henighan, Thomas; Bray, Crystal; Ndabashimiye, Georges; Bucksbaum, P H; Feng, Yiping; Herrmann, Sven; Carini, Gabriella; Pines, Jack; Hart, Philip; Kenney, Christopher; Guillet, Serge; Boutet, Sebastien; Williams, Garth; Messerschmidt, Marc; Seibert, Marvin; Moeller, Stefan; Hastings, Jerome B; Reis, David A

    2015-01-01

    X-ray scattering is a weak linear probe of matter. It is primarily sensitive to the position of electrons and their momentum distribution. Elastic X-ray scattering forms the basis of atomic structural determination while inelastic Compton scattering is often used as a spectroscopic probe of both single-particle excitations and collective modes. X-ray free-electron lasers (XFELs) are unique tools for studying matter on its natural time and length scales due to their bright and coherent ultrashort pulses. However, in the focus of an XFEL the assumption of a weak linear probe breaks down, and nonlinear light-matter interactions can become ubiquitous. The field can be sufficiently high that even non-resonant multiphoton interactions at hard X-rays wavelengths become relevant. Here we report the observation of one of the most fundamental nonlinear X-ray-matter interactions, the simultaneous Compton scattering of two identical photons producing a single photon at nearly twice the photon energy. We measure scattered...

  15. Monitoring X-Ray Emission from X-Ray Bursters

    NASA Technical Reports Server (NTRS)

    Kaaret, Philip

    1998-01-01

    The goal of this investigation was to use the All-Sky Monitor on the Rossi X-Ray Timing Explorer (RXTE) in combination with the Burst and Transient Source Experiment on the Compton Gamma-Ray Observatory to simultaneously measure the x-ray (2-12 keV) and hard x-ray (20-100 keV) emission from x-ray bursters. The investigation was successful. We made the first simultaneous measurement of hard and soft x-ray emission and found a strong anticorrelation of hard and soft x-ray emission from the X-Ray Burster 4U 0614+091. The monitoring performed under this investigation was also important in triggering target of opportunity observations of x-ray bursters made under the investigation hard x-ray emission of x-ray bursters approved for RXTE cycles 1 and 2. These observations lead to a number of papers on high-frequency quasi-periodic oscillations and on hard x-ray emission from the x-ray bursters 4U 0614+091 and 4U 1705-44.

  16. Advanced light element and low energy X-ray line analysis using Energy Dispersive Spectrometry (EDS) with Silicon Drift Detectors (SDD)

    NASA Astrophysics Data System (ADS)

    Salge, T.; Palasse, L.; Berlin, J.; Hansen, B.; Terborg, R.; Falke, M.

    2013-12-01

    Introduction: Characterization at the micro- to nano-scale is crucial for understanding many processes in earth, planetary, material and biological sciences. The composition of thin electron transparent samples can be analyzed in the nm-range using transmission electron microscopes (TEM) or, specific sample holders provided, in the field emission scanning electron microscope (FE-SEM). Nevertheless both methods often require complex sample preparation. An alternative method is to analyze bulk samples with a FE-SEM. In order to decrease the excitation volume for generated X-rays, low accelerating voltages (HV<10) are required. Consequently, only low to intermediate energy X-ray lines can be evaluated and many peak overlaps have to be deconvoluted since the high energy range is not available. Methods: A BRUKER Quantax EDS system with an XFlash Silicon Drift Detector acquired EDS spectra in spectrum images. To separate overlapping peaks, an extended atomic database [1] was used. For single channel EDS the electron beam current, solid angle, take-off angle and exposure time can be optimized to investigate the element composition. Multiple SDD setups ensure an even higher efficiency and larger collection angles for the X-ray analysis than single channel detectors. Shadowing effects are minimized in element distribution maps so that samples can be investigated quickly and sometimes in a close to natural state, with little preparation. A new type of EDS detector, the annular four channel SDD (XFlash 5060F), is placed between the pole piece and sample. It covers a very large solid angle (1.1 sr) and allows sufficient data collection at low beam currents on beam sensitive samples with substantial surface topography. Examples of applications: Results demonstrate that SDD-based EDS analysis contributes essential information on the structure at the micro- to nano scale of the investigated sample types. These include stardust analogue impact experiments [2], Chicxulub asteroid impactites [3,4], ore characterization of the Sudbury igneous complex [5], biomineralization in bacteria and insects [6], and characterization of ceramics [7] and ceramic metal joints [8]. We conclude that improvements in SDD and pulse processor technology including multi-detector and multi-segment options provide new insights because a vast amount of detailed information can be collected in a short period of time. Using the XFlash QUAD 5060F, samples can be analyzed rapidly at low beam current without carbon coating. [1] A. Assmann, A. and M. Wendt 2003. Spectrochim. Acta Part B, 58: 711-716. [2] A.T. Kearsley et al. 2013. 44th LPSC, 18-22.03.2013, The Woodlands, USA: #1910. [3] P. Schulte et al. 2010. Science 327: 1214-1218. [4] M. Nelson et al. 2012. GCA 86: 1-20. [5] Salge et al. 2013. LPI Contrib .No. 1737: 89. [6] M. Falke et al. 2013. EURO BioMat. 23-24.04.2013, Weimar, Germany. [7] H. Yurdakul et al. 2013.accepted for MC 2013, 25-30.08.2013, Regensburg, Germany [8] O. Tunckan 2010. PhD thesis. Anadolu University, Eskisehir, Turkey.

  17. SOLITONS: Bright and dark pulses in optical fibres in the vicinity of the zero-dispersion wavelength

    NASA Astrophysics Data System (ADS)

    Molotkov, I. A.; Bisyarin, M. A.

    2004-02-01

    The influence of the third-order dispersion on the propagation of short pulses in optical fibres is considered. The appearance of coupled nonlinear structures consisting of dark and bright envelope solitons is described. The wavelength range is found in the vicinity of the zero-dispersion wavelength where the effect of the third-order dispersion on the pulse propagation proves to be dominant. It is shown that in this case a nonlinear structure in the form of an embedded soliton appears.

  18. Towards attosecond X-ray pulses from the FEL

    SciTech Connect

    Zholents, Alexander A.; Fawley, William M.

    2004-07-01

    The ability to study ultrafast phenomena has been recently advanced by the demonstrated production and measurement of a single, 650-attosecond (10{sup 18} sec), VUV x-ray pulse[1] and, latter, a 250-attosecond pulse[2]. The next frontier is a production of the x-ray pulses with shorter wavelengths and in a broader spectral range. Several techniques for a generation of an isolated, attosecond duration, short-wavelength x-ray pulse based upon the ponderomotive laser acceleration [3], SASE and harmonic cascade FELs ([4] - [6]) had been already proposed. In this paper we briefly review a technique proposed in [5] and present some new results.

  19. Carrier field shock formation of long wavelength femtosecond pulses in dispersive media

    E-print Network

    Panagiotopoulos, Paris; Kolesik, Miroslav; Moloney, Jerome V

    2015-01-01

    We numerically demonstrate the formation of carrier field shocks in various dispersive media for a wide variety of input conditions using two different electric field propagation models. In addition, an investigation of the impact of numerous physical effects on carrier wave shock is performed. It is shown that in many cases a field shock is essentially unavoidable and therefore extremely important in the propagation of intense long wavelength pulses in weakly dispersive nonlinear media such as noble gases, air, and single-crystal diamond. The results presented here are expected to have a significant impact in the field of ultrashort nonlinear optics, attosecond pulse generation, and wavepacket synthesis where the use of mid-IR wavelengths is becoming increasingly more important.

  20. Fluctuation X-Ray Scattering

    SciTech Connect

    Saldin, PI: D. K.; Co-I's: J. C. H. Spence and P. Fromme

    2013-01-25

    The work supported by the grant was aimed at developing novel methods of finding the structures of biomolecules using x-rays from novel sources such as the x-ray free electron laser and modern synchrotrons

  1. Stereoscopic x-ray device

    SciTech Connect

    Muraki, T.; Yamamura, T.

    1981-09-01

    A stereoscopic x-ray device used for stereoscopic radiography generates x-rays from a pair of x-ray focal spots. The x-ray device is provided with an evacuated envelope, an x-ray target within the evacuated envelope, and a cathode structure having at least two pairs of filaments. The first pair of filaments form relatively large size x-ray focal spots on the target. The second pair of the filaments form relatively small size x-ray focal spots on the target and are situated between the first pair of filaments on the cathode structure. As a result of these two pairs of focal spots on the x-ray target, a relatively small xray device can be used to provide magnification of stereoscopic images of high stereo quality.

  2. In-situ synchrotron energy-dispersive x-ray diffraction study of thin Pd foils with Pd:D and Pd:H concentrations up to 1:1

    SciTech Connect

    Knies, D. L.; Grabowski, K. S.; Dominguez, D. D.; Qadri, S. B.; Hubler, G. K. [U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Violante, V. [ENEA, Frascati (Italy); Hu, J. Z. [NSLS, Brookhaven National Laboratory, Brookhaven, New York 11973 (United States); He, J. H. [Nova Research, Alexandria, Virginia 22308 (United States)

    2012-10-15

    Time resolved, in-situ, energy dispersive x-ray diffraction was performed in an electrolysis cell during electrochemical loading of palladium foil cathodes with hydrogen and deuterium. Concentrations of H:Pd (D:Pd) up to 1:1 in 0.1 M LiOH (LiOD) in H{sub 2}O (D{sub 2}O) electrolyte were obtained, as determined by both the Pd lattice parameter and cathode resistivity. In addition, some indications on the kinetics of loading and deloading of hydrogen from the Pd surface were obtained. The alpha-beta phase transformations were clearly delineated but no new phases at high concentration were determined.

  3. The identification of the pigments used to paint statues of Feixiange Cliff in China in late 19th century by micro-Raman spectroscopy and scanning electron microscopy/energy dispersive X-ray analysis

    NASA Astrophysics Data System (ADS)

    Jin, Pu-jun; Huang, Wei; Jianhua-Wang; Zhao, Gang; Wang, Xiao-ling

    2010-11-01

    The application of micro-Raman spectroscopy (?-RS) and scanning electron microscopy (SEM)/energy dispersive X-ray spectrometer (EDS) to the research of pigments collected from Statues of Feixiange Cliff No. 67 and No. 69 niche of Tang Dynasty in China is reported. Five kinds of pigments were found in the experimental data, including black (carbon), white (gypsum + quartz), blue (lapis lazuli) and green (Paris green + Barium sulphate). After synthesized in 1814, Paris green was reported for a large import as a light and bright green pigment to paint architectures in China from the late 19th century. The analyzed blue pigment demonstrated the similar Raman spectra to the Lâjvardina blue glazed ceramics, which indicated lapis lazuli was an artificial product. This confirmed the painting of Feixiange Cliff in the early Republic of China as the historical record, and also reveals that some pigments were imported from abroad.

  4. X-ray Dinosaurs

    NSDL National Science Digital Library

    2014-04-14

    In this activity, learners explore dinosaur fossils and skeletons. First, learners listen to "Tyrannosaurus Rex" by Daniel Cohen to learn about T. rex dinosaurs specifically. Then, learners make dinosaur tracings and drawings similar to x-rays. Learners can repeat the activity using pictures of other dinosaurs to compare and contrast various dinosaurs. This activity is featured on page 38 of the "Dinosphere" unit of study for K-2 learners.

  5. X-ray microprobe using multilayer mirrors

    NASA Astrophysics Data System (ADS)

    Underwood, J. H.; Thompson, A. C.; Wu, Y.; Giauque, R. D.

    1988-04-01

    Multilayer reflectors for the X-ray region have now progressed beyond the experimental stage to the point where they can be relied upon as optics for experimental systems, in synchrotron radiation research as well as in other fields. This paper reviews the design considerations for an X-ray microprobe, and summarizes experience with prototypes tested at both SSRL and NSLS. The optical systems described employ multilayer-coated spherical mirrors arranged in the Kirkpatrick-Baez configuration to demagnify the X-ray source by a factor of several hundred. By this means a spot of X-rays less than 10 ?m square can be produced. The optical aberrations and other factors that limit the performance are detailed, and possible ways to improve the performance are discussed. In the prototypes the spot is directed on the specimen which is carried on a stage that can be translated horizontally and vertically. The characteristic fluorescent X-rays excited by the focused 10 keV photons are analysed by an energy-dispersive Si(Li) detector, so that by scanning the stage an elemental concentration map of the specimen is built up. In a companion paper [A.C. Thompson, J.H. Underwood, Y. Wu, R.D. Giauque, K.W. Jones and M.L. Rivers, these Proceedings, p. 318] some experimental programs are described, and estimates of the elemental sensitivity are provided.

  6. Chemical analysis of uranium-niobium alloys by wavelength dispersive spectroscopy at the sigma complex

    SciTech Connect

    Papin, Pallas A.

    2012-06-01

    Uranium-niobium alloys play an important role in the nation's nuclear stockpile. It is possible to chemically quantify this alloy at a micron scale by using a technique know as wavelength dispersive spectroscopy. This report documents how this technique was used and how it is possible to reproduce measurements of this type. Discussion regarding the accuracy and precision of the measurements, the development of standards, and the comparison of different ways to model the matrices are all presented.

  7. Pulse delay measurements in the zero material dispersion wavelength region for optical fibers

    Microsoft Academic Search

    L. G. Cohen; Chinlon Lin

    1977-01-01

    Subnanosecond pulses in the 1120-1550-nm region are generated by multiple-order stimulated Raman scattering in a small core single-mode silica fiber pumped by a Q-switched and mode-locked Nd:YAG laser at 1064 nm. These near ir pulses are injected into various km long test fibers, and relative time delay changes between different wavelengths are used to determine dispersion in a region where

  8. Evaluation of micro-energy dispersive X-ray fluorescence and histochemical tests for aluminium detection in plants from High Altitude Rocky Complexes, Southeast Brazil.

    PubMed

    Campos, Naiara V; Pereira, Tiago A R; Machado, Mariana F; Guerra, Marcelo B B; Tolentino, Gláucia S; Araújo, Josiane S; Rezende, Maíra Q; Silva, Maria Carolina N A da; Schaefer, Carlos E G R

    2014-03-01

    The soils developed under High Altitude Rocky Complexes in Brazil are generally of very low chemical fertility, with low base saturation and high exchangeable aluminium concentration. This stressful condition imposes evolutionary pressures that lead to ecological success of plant species that are able to tolerate or accumulate high amounts of aluminium. Several analytical methods are currently available for elemental mapping of biological structures, such as micro-X-ray fluorescence (?-EDX) and histochemical tests. The aim of this study was to combine ?-EDX analysis and histochemical tests to quantify aluminium in plants from High Altitude Rocky Complexes, identifying the main sites for Al-accumulation. Among the studied species, five showed total Al concentration higher than 1000 mg kg-1. The main Al-hyperaccumulator plants, Lavoisiera pectinata, Lycopodium clavatum and Trembleya parviflora presented positive reactions in the histochemical tests using Chrome Azurol and Aluminon. Strong positive correlations were observed between the total Al concentrations and data obtained by ?-EDX analysis. The ?-EDX analysis is a potential tool to map and quantify Al in hyperaccumulator species, and a valuable technique due to its non-destructive capacity. Histochemical tests can be helpful to indicate the accumulation pattern of samples before they are submitted for further ?-EDX scrutiny. PMID:24676168

  9. X-Ray Astronomy

    NASA Technical Reports Server (NTRS)

    Wu, S. T.

    2000-01-01

    Dr. S. N. Zhang has lead a seven member group (Dr. Yuxin Feng, Mr. XuejunSun, Mr. Yongzhong Chen, Mr. Jun Lin, Mr. Yangsen Yao, and Ms. Xiaoling Zhang). This group has carried out the following activities: continued data analysis from space astrophysical missions CGRO, RXTE, ASCA and Chandra. Significant scientific results have been produced as results of their work. They discovered the three-layered accretion disk structure around black holes in X-ray binaries; their paper on this discovery is to appear in the prestigious Science magazine. They have also developed a new method for energy spectral analysis of black hole X-ray binaries; four papers on this topics were presented at the most recent Atlanta AAS meeting. They have also carried Monte-Carlo simulations of X-ray detectors, in support to the hardware development efforts at Marshall Space Flight Center (MSFC). These computation-intensive simulations have been carried out entirely on the computers at UAH. They have also carried out extensive simulations for astrophysical applications, taking advantage of the Monte-Carlo simulation codes developed previously at MSFC and further improved at UAH for detector simulations. One refereed paper and one contribution to conference proceedings have been resulted from this effort.

  10. X-Ray Exam: Hip

    MedlinePLUS

    ... technician takes the X-rays. An X-ray technician in the radiology department of a hospital or a health care ... how the lateral view usually is done. The technician will return to reposition your ... be brought to the radiology department, a portable X-ray machine can be ...

  11. X-Ray Exam: Forearm

    MedlinePLUS

    ... X-rays are performed by an X-ray technician in the radiology department of a hospital, a radiology center, or ... and can't easily be brought to the radiology department, a portable X-ray ... rooms. The technician will seat your child, position the forearm on ...

  12. Bone X-Ray (Radiography)

    MedlinePLUS Videos and Cool Tools

    ... x-rays. top of page What does the equipment look like? View larger with caption The equipment typically used for bone x-rays consists of ... and joint abnormalities, such as arthritis. X-ray equipment is relatively inexpensive and widely available in emergency ...

  13. Tunable X-ray source

    DOEpatents

    Boyce, James R. (Williamsburg, VA)

    2011-02-08

    A method for the production of X-ray bunches tunable in both time and energy level by generating multiple photon, X-ray, beams through the use of Thomson scattering. The method of the present invention simultaneously produces two X-ray pulses that are tunable in energy and/or time.

  14. Two tracks in Three Dimensions: Correlations between optical, soft X-ray and hard X-ray brightness variations of the Neutron Star X-ray Binary Aquila X-1

    NASA Astrophysics Data System (ADS)

    Scarpaci, John; Maitra, Dipankar

    2015-01-01

    We present long-term multi-wavelength correlation among the fluxes in optical, soft x-ray, and hard x-ray wavelengths in the neutron star x-ray binary system Aquila X-1. We present over fourteen years of optical data obtained with the SMARTS 1.3m telescope, paired with quasi-simultaneous observations in the 2-10 keV soft X-ray range (from RXTE/ASM and MAXI), and in the 15-50 keV hard X-ray range (from Swift/BAT). We find no single correlation between the long-term optical, soft X-ray and hard X-ray fluxes, extending similar findings by Maitra & Bailyn (2008) using only the optical and soft X-ray data till 2007. In this work we show that there are in fact two distinct correlations among these 3 wavelength bands, viz., when quasi-simultaneous optical, soft X-ray, and hard X-ray fluxes are shown on a 3D plot they fall in two distinct branches. This is strongly indicative of two distinct physical mechanisms that may be operating during outbursts of Aql X-1. We speculate on plausible scenarios such as recently discovered transitions between radio-pulsar phase and an X-ray bright phase for some neutron star binaries.

  15. Soft x-ray lasers

    SciTech Connect

    Matthews, D.L.; Rosen, M.D.

    1988-12-01

    One of the elusive dreams of laser physicists has been the development of an x-ray laser. After 25 years of waiting, the x-ray laser has at last entered the scientific scene, although those now in operation are still laboratory prototypes. They produce soft x rays down to about five nanometers. X-ray lasers retain the usual characteristics of their optical counterparts: a very tight beam, spatial and temporal coherence, and extreme brightness. Present x-ray lasers are nearly 100 times brighter that the next most powerful x-ray source in the world: the electron synchrotron. Although Lawrence Livermore National Laboratory (LLNL) is widely known for its hard-x-ray laser program which has potential applications in the Strategic Defense Initiative, the soft x-ray lasers have no direct military applications. These lasers, and the scientific tools that result from their development, may one day have a place in the design and diagnosis of both laser fusion and hard x-ray lasers. The soft x-ray lasers now in operation at the LLNL have shown great promise but are still in the primitive state. Once x-ray lasers become reliable, efficient, and economical, they will have several important applications. Chief among them might be the creation of holograms of microscopic biological structures too small to be investigated with visible light. 5 figs.

  16. X-ray lithography source

    DOEpatents

    Piestrup, Melvin A. (Woodside, CA); Boyers, David G. (Mountain View, CA); Pincus, Cary (Sunnyvale, CA)

    1991-01-01

    A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and elminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an exellent moderate-priced X-ray source for lithography.

  17. X-ray lithography source

    DOEpatents

    Piestrup, M.A.; Boyers, D.G.; Pincus, C.

    1991-12-31

    A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits is disclosed. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and eliminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an excellent moderate-priced X-ray source for lithography. 26 figures.

  18. Soft x-ray interferometry

    SciTech Connect

    Not Available

    1993-09-01

    The purpose of the soft x-ray interferometry workshop held at Lawrence Berkeley Laboratory was to discuss with the scientific community the proposed technical design of the soft x-ray Fourier-transform spectrometer being developed at the ALS. Different design strategies for the instrument`s components were discussed, as well as detection methods, signal processing issues, and how to meet the manufacturing tolerances that are necessary for the instrument to achieve the desired levels of performance. Workshop participants were encouraged to report on their experiences in the field of Fourier transform spectroscopy. The ALS is developing a Fourier transform spectrometer that is intended to operate up to 100 eV. The motivation is solely improved resolution and not the throughput (Jaquinot) or multiplex (Fellgett) advantage, neither of which apply for the sources and detectors used in this spectral range. The proposed implementation of this is via a Mach-Zehnder geometry that has been (1) distorted from a square to a rhombus to get grazing incidence of a suitable angle for 100 eV and (2) provided with a mirror-motion system to make the path difference between the interfering beams tunable. The experiment consists of measuring the emergent light intensity (I(x)) as a function of the path difference (x). The resolving power of the system is limited by the amount of path difference obtainable that is 1 cm (one million half-waves at 200{angstrom} wavelength) in the design thus allowing a resolving power of one million. The free spectral range of the system is limited by the closeness with which the function I(x) is sampled. It is proposed to illuminate a helium absorption cell with roughly 1%-band-width light from a monochromator thus allowing one hundred aliases without spectral overlap even for sampling of I(x) at one hundredth of the Nyquist frequency.

  19. A small gas puff Z-pinch X-ray source

    Microsoft Academic Search

    P. Choi; A. E. Dangor; C. Deeney

    1987-01-01

    The gas puff Z-pinch is an intense pulsed plasma X-ray source energized by a capacitor bank. Typically 5-10 percent of the electrical energy stored in the bank is converted into X-ray radiations with wavelengths less than 100 A. Such devices have applications in X-ray microscopy, lithography, spectroscopy and X-ray optics engineering. Here the results of a parametric study of the

  20. In situ observations of temperature- and pressure-induced phase transitions in TiH 2: Angle-dispersive and synchrotron energy-dispersive X-ray diffraction studies

    Microsoft Academic Search

    Patricia E. Kalita; Andrew L. Cornelius; Kristina E. Lipinska-Kalita; Cédric L. Gobin; H. Peter Liermann

    2008-01-01

    We investigated the behavior of the structure of titanium hydride (TiH2), an important compound in hydrogen storage research, at elevated temperatures (0–120°C) and high pressures (1bar–34GPa). Temperature-induced changes of TiH2 as indicated in the alteration of the ambient X-ray demonstrated a cubic to tetragonal phase transition occurring at about 17°C. The main focus of this study was to identify any

  1. In situ observations of temperature- and pressure-induced phase transitions in TiH[subscript 2]: Angle-dispersive and synchrotron energy-dispersive X-ray diffraction studies

    Microsoft Academic Search

    Patricia E. Kalita; Andrew L. Cornelius; Kristina E. Lipinska-Kalita; Cedric L. Gobin; H. Peter Liermann

    2009-01-01

    We investigated the behavior of the structure of titanium hydride (TiHâ), an important compound in hydrogen storage research, at elevated temperatures (0-120 C) and high pressures (1 bar-34 GPa). Temperature-induced changes of TiHâ as indicated in the alteration of the ambient X-ray demonstrated a cubic to tetragonal phase transition occurring at about 17 C. The main focus of this study

  2. Paper-based diffusive gradients in thin films technique coupled to energy dispersive X-ray fluorescence spectrometry for the determination of labile Mn, Co, Ni, Cu, Zn and Pb in river water

    NASA Astrophysics Data System (ADS)

    Almeida, Eduardo de; Nascimento Filho, Virgílio Franco do; Menegário, Amauri Antonio

    2012-05-01

    The diffusive gradients in thin films (DGT) technique has shown enormous potential for labile metal monitoring in fresh water due to the preconcentration, time-integrated, matrix interference removal and speciation analytical features. In this work, the coupling of energy dispersive X-ray fluorescence (EDXRF) with paper-based DGT devices was evaluated for the direct determination of Mn, Co, Ni, Cu, Zn and Pb in fresh water. The DGT samplers were assembled with cellulose (Whatman 3 MM chromatography paper) as the diffusion layer and a cellulose phosphate ion exchange membrane (Whatman P 81 paper) as the binding agent. The diffusion coefficients of the analytes on 3 MM chromatography paper were calculated by deploying the DGT samplers in synthetic solutions containing 500 ?g L- 1 of Mn, Co, Ni, Cu, Zn and Pb (4 L at pH 5.5 and ionic strength at 0.05 mol L- 1). After retrieval, the DGT units were disassembled and the P 81 papers were dried and analysed by EDXRF directly. The 3 MM chromatographic paper diffusion coefficients of the analytes ranged from 1.67 to 1.87 × 10- 6 cm2 s- 1. The metal retention and phosphate group homogeneities on the P 81 membrane was studied by a spot analysis with a diameter of 1 mm. The proposed approach (DGT-EDXRF coupling) was applied to determine the analytes at five sampling sites (48 h in situ deployment) on the Piracicaba river basin, and the results (labile fraction) were compared with 0.45 ?m dissolved fractions determined by synchrotron radiation-excited total reflection X-ray fluorescence (SR-TXRF). The limits of detection of DGT-EDXRF coupling for the analytes (from 7.5 to 26 ?g L- 1) were similar to those obtained by the sensitive SR-TXRF technique (3.8 to 9.1 ?g L- 1).

  3. Dispersive properties in photonic crystals applications to beam-steering and wavelength demultiplexing

    NASA Astrophysics Data System (ADS)

    Shafiiha, Roshanak

    Photonic crystals are artificial periodic structures with interesting optical properties which are not often found in naturally formed materials. Most of the applications proposed to date, such as photonic crystal microcavity lasers and photonic crystal waveguides, have primarily utilized the photonic bandgap to confine the light within the defect region of the crystal lattice or to control the light propagation through the defect area. However, there are other applications based on anomalous dispersion observed in light propagation through the crystal lattice itself which are unique and potentially useful for the photonic miniaturization and integration with planar optical circuits in next-generation communication systems. This dissertation investigates the fundamental dispersive properties of one-dimensional and two-dimensional photonic crystal slabs. By studying the photonic band structure and constant frequency contours we can predict wavelength dependent spatial beam shifting in these devices, as well as other wavelength dependent and angular dependent characteristics such as superprism and super-collimation effects. We will discuss the practical limitations of using a tightly focused input beam with finite spectral range and how this can affect the performance of super-dispersive photonic crystals in real-world applications.

  4. PXAMS -- Projectile X ray AMS: X ray yields and applications

    SciTech Connect

    McAninch, J.E.; Bench, G.S.; Freeman, S.P.H.T.; Roberts, M.L.; Southon, J.R.; Vogel, J.S.; Proctor, I.D. [Lawrence Livermore National Lab., CA (United States). Center for Accelerator Mass Spectrometry

    1994-10-07

    Characteristic x rays have recently been explored as a method for the detection and identification of ions in accelerator mass spectrometry (AMS). After analysis in the AMS spectrometer, the ions stop in an appropriately chosen target and the induced x rays identify the ions by atomic number. For the application of AMS to higher mass isotopes, characteristic x rays allow significantly better discrimination of competing atomic isobars than is possible using energy loss detectors. Characteristic x rays also show promise as a convenient component in hybrid detection systems. Measurements of x ray yields are presented for Si, Fe, Ni, Se, Mo, and Pd ions of 0.5--2 MeV/AMU. The yields rise by more than a factor of 10 over this energy range, and approach 1 x-ray per incident ion at 2 MeV/AMU for the lighter ions. Preliminary work on the application of PXAMS to the detection of {sup 79}Se is described.

  5. Iron redistribution in a zirconium alloy after neutron and proton irradiation studied by energy-dispersive X-ray spectroscopy (EDX) using an aberration-corrected (scanning) transmission electron microscope

    NASA Astrophysics Data System (ADS)

    Francis, E. M.; Harte, A.; Frankel, P.; Haigh, S. J.; Jädernäs, D.; Romero, J.; Hallstadius, L.; Preuss, M.

    2014-11-01

    Zirconium alloys used as cladding materials in nuclear reactors can exhibit accelerated irradiation induced growth, often termed linear growth, after sustained neutron irradiation. This phenomenon has been linked to the formation of -component dislocation loops and to the concentration of interstitial solute atoms. It is well documented for the Zircaloys that Fe dissolves from second phase particles (SPPs) during irradiation thus increasing the interstitial solute concentration in the matrix. However, no progress has yet been made into understanding whether a similar process occurs for the newer ZIRLO™ alloys. We aim to overcome this shortcoming here by studying compositional changes in second phase particles in Low Tin ZIRLO™ after neutron and proton irradiation using energy dispersive X-ray (EDX) spectroscopy. Material irradiated to 18 dpa (displacements per atom) using neutrons and to 2.3 and 7 dpa by protons was investigated. The results show that Fe is lost from Zr-Nb-Fe-SPPs during both neutron and proton irradiation. Prior to irradiation, Fe was detected at the interface of ?-Nb-SPPs. This Fe enrichment is also dispersed during irradiation. Qualitatively, excellent agreement was found regarding the elemental redistribution processes observed after proton and neutron irradiation.

  6. X-Ray and X-Ray-CT

    Microsoft Academic Search

    Willi A. Kalender; Paul Deak; Klaus Engelke; Marek Karolczak

    \\u000a Since their discovery in 1895, X-rays have been widely used for imaging humans. Recently, they have also gained an importance\\u000a in small animal imaging (SAI). Most techniques known from clinical medicine, including single- and dual-energy X-ray imaging,\\u000a have been successfully ported to SAI and are the subject of this chapter. As trivial as it is, simple X-ray examinations may\\u000a bring

  7. Accretion and Outflows in X-ray Binaries: What's Really Going on During X-ray Quiescence

    NASA Astrophysics Data System (ADS)

    MacDonald, Rachel K. D.; Bailyn, Charles D.; Buxton, Michelle

    2015-01-01

    X-ray binaries, consisting of a star and a stellar-mass black hole, are wonderful laboratories for studying accretion and outflows. They evolve on timescales quite accessible to us, unlike their supermassive cousins, and allow the possibility of gaining a deeper understanding of these two common astrophysical processes. Different wavelength regimes reveal different aspects of the systems: radio emission is largely generated by outflows and jets, X-ray emission by inner accretion flows, and optical/infrared (OIR) emission by the outer disk and companion star. The search for relationships between these different wavelengths is thus an area of active research, aiming to reveal deeper connections between accretion and outflows.Initial evidence for a strong, tight correlation between radio and X-ray emission has weakened as further observations and newly-discovered sources have been obtained. This has led to discussions of multiple tracks or clusters, or the possibility that no overall relation exists for the currently-known population of X-ray binaries. Our ability to distinguish among these options is hampered by a relative lack of observations at lower luminosities, and especially of truly X-ray quiescent (non-outbursting) systems. Although X-ray binaries spend the bulk of their existence in quiescence, few quiescent sources have been observed and multiple observations of individual sources are largely nonexistent. Here we discuss new observations of the lowest-luminosity quiescent X-ray binary, A0620-00, and the place this object occupies in investigations of the radio/X-ray plane. For the first time, we also incorporate simultaneous OIR data with the radio and X-ray data.In December 2013 we took simultaneous observations of A0620-00 in the X-ray (Chandra), the radio (EVLA), and the OIR (SMARTS 1.3m). These X-ray and radio data allowed us to investigate similarities among quiescent X-ray binaries, and changes over time for this individual object, in the radio/X-ray plane. In addition, our OIR observations allowed us to examine the radio and X-ray information in relation to the different OIR states of behavior (passive and active) known to exist during X-ray quiescence.

  8. X-ray microscopy of human malaria

    SciTech Connect

    Magowan, C.; Brown, J.T.; Mohandas, N.; Meyer-Ilse, W. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States)

    1997-04-01

    Associations between intracellular organisms and host cells are complex and particularly difficult to examine. X-ray microscopy provides transmission images of subcellular structures in intact cells at resolutions superior to available methodologies. The spatial resolution is 50-60nm with a 1 micron depth of focus, superior to anything achievable with light microscopy. Image contrast is generated by differences in photoelectric absorption by the atoms in different areas (i.e. subcellular structures) throughout the full thickness of the sample. Absorption due to carbon dominates among all the elements in the sample at 2.4 nm x-ray wavelength. Thus images show features or structures, in a way not usually seen by other types of microscopy. The authors used soft x-ray microscopy to investigate structural development of Plasmodium falciparum malaria parasites in normal and genetically abnormal erythrocytes, and in infected erythrocytes treated with compounds that have anti-malarial effects. X-ray microscopy showed newly elaborated structures in the cytosol of unstained, intact erythrocytes, redistribution of mass (carbon) in infected erythrocytes, and aberrant parasite morphology. Better understanding of the process of intracellular parasite maturation and the interactions between the parasite and its host erythrocyte can help define new approaches to the control of this deadly disease.

  9. Characterization of zirconia–thoria–urania ceramics by X-ray and electron interactions

    Microsoft Academic Search

    Gini Curran; Y. Sevestre; Wendy Rattray; Patrick Allen; K. R. Czerwinski

    2003-01-01

    X-ray and electron interactions with matter were used as probes to characterize the structure and chemistry of zirconia–thoria–urania ceramics. The ceramics were prepared by coprecipitation of Zr, Th and U salts. In this study, transmission electron microscopy (TEM) techniques such as energy dispersive X-ray (EDX) analysis and electron energy loss spectroscopy (EELS) complement X-ray diffraction, extended X-ray absorption fine structure

  10. Dispersion-compensated wavelength beam combining of quantum-cascade-laser arrays.

    PubMed

    Goyal, Anish K; Spencer, Melissa; Shatrovoy, Oleg; Lee, Benjamin G; Diehl, Laurent; Pfluegl, Christian; Sanchez, Antonio; Capasso, Federico

    2011-12-19

    A multiwavelength array of distributed feedback (DFB) quantum cascade lasers (QCLs) that spans ? = 8.28 to 9.62 ?m is wavelength beam combined (WBC) using both single-grating and dual-grating designs. WBC with a single grating results in a pointing error of 3-times the beam divergence for a single laser and arises from the nonlinear dispersion of the grating. By adding a second grating to compensate for the nonlinear dispersion, the pointing error is reduced to only 13% of the beam divergence for a single laser. A transceiver based on the dual-grating-WBC QCL was used to measure the transmittance of a polymer sheet placed between itself and a retroreflector over a round-trip distance of 70 meters. PMID:22274256

  11. Effect of frequency chirp on supercontinuum generation in silicon waveguides with two zero-dispersion wavelengths

    NASA Astrophysics Data System (ADS)

    Cao, Yanmei; Zhang, Libin; Fei, Yonghao; Lei, Xun; Chen, Shaowu

    2015-01-01

    The influence of initial chirp on supercontinuum generation in SOI rib waveguide with two zero-dispersion wavelengths was studied numerically, based on the generalized nonlinear Schrödinger equation (GNSE). The full-width at half-maximum (FWHM) and the peak power of the pre-chirped hyperbolic secant in the simulation are 50 fs and 50 W, respectively. The simulation results indicate that a positive initial chirp makes the energy transfer to the normal dispersion zone by affecting self-phase modulation (SPM) and four-wave mixing (FWM) processes, and therefore enhances the supercontinuum bandwidth as well as improves the spectral flatness. In particular, at the optimal initial chirp parameter of C=3, the bandwidth at -10 dB level increases to about 1620 nm (from 1140 to 2760 nm), exceeding an octave-spanning.

  12. Analytical possibilities of different X-ray fluorescence systems for determination of trace elements in aqueous samples pre-concentrated with carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Marguí, E.; Zawisza, B.; Skorek, R.; Theato, T.; Queralt, I.; Hidalgo, M.; Sitko, R.

    2013-10-01

    This study was aimed to achieve improved instrumental sensitivity and detection limits for multielement determination of V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Se, Pb and Cd in liquid samples by using different X-ray fluorescence (XRF) configurations (a benchtop energy-dispersive X-ray fluorescence spectrometer, a benchtop polarised energy-dispersive X-ray fluorescence spectrometer and a wavelength-dispersive X-ray fluorescence spectrometer). The preconcentration of metals from liquid solutions consisted on a solid-phase extraction using carbon nanotubes (CNTs) as solid sorbents. After the extraction step, the aqueous sample was filtered and CNTs with the absorbed elements were collected onto a filter paper which was directly analyzed by XRF. The calculated detection limits in all cases were in the low ng mL- 1 range. Nevertheless, results obtained indicate the benefits, in terms of sensitivity, of using polarized X-ray sources using different secondary targets in comparison to conventional XRF systems, above all if Cd determination is required. The developed methodologies, using the aforementioned equipments, have been applied for multielement determination in water samples from an industrial area of Poland.

  13. Hard X-ray and UV Two-ribbon Flares

    NASA Astrophysics Data System (ADS)

    Cheng, Jianxia; Qiu, J.

    2010-05-01

    It is well known that two-ribbon flares observed in Halpha and UV wavelengths mostly exhibit compact and localized hard X-ray sources. The reason is largely unknown. In this paper, we present comprehensive analysis of a two-ribbon flare observed on 2005, January 15 in UV 1600 Å, and the hard X-ray imaging and spectroscopic observations by RHESSI are analyzed. We show that (1) UV brightening is substantially enhanced when the hard X-ray source moves into the location, and during the hard X-ray transit, the UV light curve is temporally correlated with hard X-ray light curve. After the passage of the HXR source, the UV light curve exhibits smooth monotonically decay. (2) We compute the hard X-ray source motion, and decompose it into parallel and perpendicular motion, finding that the parallel motion dominates the rise of the hard X-ray light curve, and the perpendicular motion starts and dominates at the peak of the hard X-ray. The apparent motion speed is 20-40 km/s; we also follow the UV brightening speed following the approach by Qiu (2009), finding that the motion pattern and apparent speed the same as hard X-ray sources; The hard X-ray motion speed during the cooling time of UV would produce a ribbon of length 40", just about the UV ribbon length. (3) We also estimate the cooling time (e-slope) of UV brightening, by deconvolving the UV curve from the hard X-ray curve; which gives 15 - 30 min cooling time. It is, of course, related to the maximum intensity of UV. The above analyses provide evidence that UV brightening is due to beam heating, the thermal origin cannot be excluded, but would produce heating of 1 order of magnitude weaker. The UV ribbon for this event is due to the cooling time.

  14. Scandium/carbon filters for soft x rays

    NASA Astrophysics Data System (ADS)

    Artioukov, I. A.; Kasyanov, Yu. S.; Kopylets, I. A.; Pershin, Yu. P.; Romanova, S. A.

    2003-11-01

    This Note deals with thin-film soft x-ray filters for operation at the wavelengths near carbon K edge (˜4.5 nm). The filters were fabricated by magnetron sputtering deposition of thin layers of scandium (total thickness 0.1-0.2 ?m) onto films of polypropylene (thickness 1.5 ?m) and polyimide (thickness 0.15-0.3 ?m). To protect the scandium layers from oxidation processes in the ambient environment, the filters were coated with 3 nm layers of carbon. The measured transmissions of 0.1 ?m Sc/C filters are about 0.6 at the working wavelength and ˜10-4 in the visible. The developed soft x-ray filters can be useful for soft x-ray investigations of carbon-containing materials and biological structures, utilizing radiation of laser produced plasmas and other compact x-ray sources.

  15. Topological X-Rays Revisited

    ERIC Educational Resources Information Center

    Lynch, Mark

    2012-01-01

    We continue our study of topological X-rays begun in Lynch ["Topological X-rays and MRI's," iJMEST 33(3) (2002), pp. 389-392]. We modify our definition of a topological magnetic resonance imaging and give an affirmative answer to the question posed there: Can we identify a closed set in a box by defining X-rays to probe the interior and without…

  16. X-ray Absorption Spectroscopy

    SciTech Connect

    Yano, Junko; Yachandra, Vittal K.

    2009-07-09

    This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.

  17. Radio imaging observations of hard x-ray microflares observed by RHESSI

    NASA Astrophysics Data System (ADS)

    Kundu, M.; Trottet, G.; Garaimov, V.; Grigis, P.

    We describe the properties of two sets of microflares observed simultaneously by RHESSI (Ramaty High Energy Solar Spectroscopic Imager) in hard X-rays and by two radio imaging instruments--NoRH (Nobeyama Radio Heliograph) in microwaves (17 GHz) and NRH (Nancay Radio Heliograph) at metric wavelengths. The two sets of events occurred in two different time zones, and as a result we do not have simultaneous imaging data in microwaves and metric wavlengths for the same RHESSI events. We'll discuss four events--two observed by NoRH in microwaves and two observed by NRH in meter waves, along with RHESSI events. The microwave (17 GHz) events occurred in AR 9934 at 03:58 UT May 3, 2002 and at 05:08 UT May 4, 2002. We have detected microwave (17 & 34 GHz) emissions in association with RHESSI microflares in the energy range 3-50 keV. The microwave emission comes from footpoints for higher energies, and from the entire mini or small flaring loop for lower energies. The relative positions of microwaves and hard X-rays are as they should be in normal flares. Sometimes the two sources coincide, at other times the two sources are at opposite ends of the flaring loop. One sees the mini flaring loops clearly in NoRH images. RHESSI maps at the time of maximum X-ray emission during the event of May 3, 2002 clearly show an X-ray loop in the range 3-6 keV and two footpoints of the loop in the 6-12 and 12-25 keV ranges. These footpoints are located above opposite magnetic polarities as seen in overlays of hard X-ray images on the MDI images. The MDI magnetograms taken before the microflares show rapid evolution of the magnetic field, including sometimes the emergence of a new region. The hard X-ray spectrum of microwave associated RHESSI microflares can be fit by a thermal component (EM ˜ 3× 1046 cm-3) at low energies (3-6 keV) and a nonthermal component (with slope -3.2) at higher energies. The two metric events imaged by NRH occurred on August 5 and September 3, 2003, one located on the disk and the other at the limb. The RHESSI microflare sources are compact. They are accompanied by a series of metric type III bursts at 150-410 MHz originating from sources located above the RHESSI HXR source. Their source positions show frequency dispersion as expected from plasma radiation sources. The properties of these microflare sources in hard X-rays, microwave and meter wavelengths will be discussed.

  18. Filters for soft X-ray solar telescopes

    NASA Technical Reports Server (NTRS)

    Spiller, Eberhard; Grebe, Kurt; Golub, Leon

    1990-01-01

    Soft X-ray telescopes require filters that block visible and infrared light and have good soft X-ray transmission. The optical properties of possible materials are discussed, and the fabrication and testing methods for the filters used in a 10-inch normal incidence telescope for 63 A are described. The best performances in the 44-114-A wavelength range are obtained with foils of carbon and rhodium.

  19. Development of x-ray laser media. measurement of gain and development of cavity resonators for wavelengths near 130 angstroms. Volume 3. Annual scientific report, 1 Jan31 Dec 82

    Microsoft Academic Search

    Forsyth

    1983-01-01

    In this document the authors summarize our investigation of the reflecting properties of x-ray multilayers. The breadth of this investigation indicates the utility of the difference equation formalism in the analysis of such structure. The formalism is particularly useful in analyzing multilayers whose structure is not a simple periodic bilayer. The complexity in structure can be either intentional, as in

  20. Basic principles of Synchrotron Radiation-Induced X-Ray Fluorescence (SRXRF)

    SciTech Connect

    Gigante, G.E. (Rome Univ. (Italy). Dipt. di Fisica); Hanson, A.L. (Brookhaven National Lab., Upton, NY (USA))

    1990-05-01

    The characteristic x rays can be used as powerful analytical tools for qualitative and quantitative determination of the major, minor and trace composition of materials. X Ray Fluorescence (XRF) techniques used for almost four decade to solve many problems in basic, applied science, and in industry. The XRF techniques that were developed initially used crystal spectrometers, and are referred to in literature as Wavelength Dispersive (WD) techniques. These WD techniques are still used in many fields and have the merit of a excellent energy resolution that allows for the analysis of many elements while avoiding the overlapping of some fluorescence peaks. They are also particularly useful in a matrix that produces copious quantities of a particular radiation. The principal disadvantages of a WD system are the low efficiency of crystal and the reduced energy region in which crystal spectrometer can be used. In the 1960's, Solid State Detectors (SSD) were developed with energy resolution such that the Energy Dispersive XRF techniques could be developed. These SSD's overcame some of the limitations of the WD techniques. The most attractive characteristics of the EDXRF techniques are in their intrinsic multielemental and non destructive capabilities. The development of the high intensity, high brilliance Synchrotron Radiation (SR) sources have open the possibility to make microanalyses using the XRF techniques, increasing the interest of the scientific community for these techniques. In this paper the basic concepts of the XRF technique are reviewed taking in account the availability of the new sources of x rays. 32 refs., 7 figs.

  1. Numerical analysis for a solid-core photonic crystal fiber with tunable zero dispersion wavelengths

    NASA Astrophysics Data System (ADS)

    Barrientos-García, A.; Sukoivanov, Igor A.; Andrade-Lucio, J. A.; Guryev, Igor; Shulika, Oleksiy V.; Hernandez-García, J. C.; Ramos-Ortiz, G.

    2014-09-01

    Here we propose a simple design for a solid-core photonic crystal fiber made of silica by keeping the golden ratio (1.618) between pitch and air hole diameter ? /d in a subset of six rings of air-holes with hexagonal arrangement. In the case when we have a pitch equal to one micron (? =1 ?m), we need air-holes diameters d=0.618 ?m in order to obtain the golden ratio parameter (?/d=1.618), and achieve two zero dispersion wavelength (ZDW) points at 725 nm and 1055 nm; this gives us the possibility to use this fiber in supercontinuum generation using a laser emission close to that points. We analyzed a series of fibers using this relation and show the possibilities of tunable ZDW in a wide range of wavelengths from 725 nm to 2000 nm with low losses and small effective area. In agreement with the ZDW point needed, the geometry of the structure can be modified to the point of having only three rings of air holes that surround the solid core with low losses and good confinement mode. The design proposed here is analyzed using the finite element method (FEM) with perfectly matched layers (PML), including the material dispersion directly into the model applying the Sellmeier's equation.

  2. New bright soft X-ray selected ROSAT AGN: I. Infrared-to-X-ray spectral energy distributions

    E-print Network

    D. Grupe; K. Beuermann; H. -C. Thomas; K. Mannheim; H. H. Fink

    1997-10-27

    We present results of an infrared-to-X-ray study of 76 bright soft X-ray selected Seyfert galaxies discovered in the ROSAT All-Sky Survey. These objects are characterized by steep X-ray spectra in the 0.2-2.0 keV bandpass with power law energy spectral indices in the range of 1.3 to 8 and a lack of internal absorption by neutral hydrogen. Our sample selection based on hardness ratio yields a mean X-ray slope of alpha-X = 2.1, steeper than in any other known AGN population. At optical wavelengths, the soft AGN have significantly bluer spectra than a comparison sample of AGN with a canonical, harder X-ray spectrum, whereas the slope between 5500 Angstrom and 1 keV is the same. This is consistent with a more pronounced Big Blue Bump emission component in the soft X-ray selected AGN. The blueness of the optical spectra increases with the softness of the X-ray spectra and with the luminosity, saturating at an approximate F_nu proportional to nu^+0.3 spectrum. Such properties are expected if most of the Big Blue Bump emission originates in a (comptonized) accretion disk and accretion rate to mass ratio is higher than in AGN with a hard X-ray spectrum.

  3. In situ observations of temperature- and pressure-induced phase transitions in TiH[subscript 2]: Angle-dispersive and synchrotron energy-dispersive X-ray diffraction studies

    SciTech Connect

    Kalita, Patricia E.; Cornelius, Andrew L.; Lipinska-Kalita, Kristina E.; Gobin, Cedric L.; Liermann, H. Peter (UNLV); (CIW)

    2009-04-09

    We investigated the behavior of the structure of titanium hydride (TiH{sub 2}), an important compound in hydrogen storage research, at elevated temperatures (0-120 C) and high pressures (1 bar-34 GPa). Temperature-induced changes of TiH{sub 2} as indicated in the alteration of the ambient X-ray demonstrated a cubic to tetragonal phase transition occurring at about 17 C. The main focus of this study was to identify any pressure-induced structural transformations, including possible phase transitions, in TiH{sub 2}. Synchrotron X-ray diffraction studies were carried out in situ (diamond anvil cell) in a compression sequence up to 34 GPa and in subsequent decompression to ambient pressure. The pressure evolution of the diffraction patterns revealed a cubic (Fm-3m) to tetragonal (I4/mmm) phase transition at 2.2 GPa. The high-pressure phase persisted up to 34 GPa. After decompression to ambient conditions the observed phase transition was completely reversible. A Birch-Murnaghan fit of the unit cell volume as a function of pressure yielded a zero-pressure bulk modulus K{sub 0} = 146(14) GPa, and its pressure derivative K{prime}{sub 0} = 6(1) for the high-pressure tetragonal phase of TiH{sub 2}.

  4. X-ray laser interferometry: A new tool for AGEX

    SciTech Connect

    Wan, A.S.; Moreno, J.C.; Libby, S.B. [and others

    1995-10-01

    Collisionally pumped soft x-ray lasers now operate over a wavelength range extending from 4--40 nm. With the recent advances in the development of multilayer mirrors and beamsplitters in the soft x-ray regime, we can utilize the unique properties of x-ray lasers to study large, rapidly evolving laser-driven plasmas with high electron densities. By employing a shorter wavelength x-ray laser, as compared to using conventional optical laser as the probe source, we can access a much higher density regime while reducing refractive effects which limit the spatial resolution and data interpretation. Using a neon-like yttrium x-ray laser which operates at a wavelength of 15.5 mn, we have performed a series of soft x-ray laser interferometry experiments, operated in the skewed Mach-Zehnder configuration, to characterize plasmas relevant to both weapons and inertial confinement fusion. The two-dimensional density profiles obtained from the interferograms allow us to validate and benchmark our numerical models used to study the physics in the high-energy density regime, relevant to both weapons and inertial confinement fusion.

  5. X-Ray Interactions with Matter from the Center for X-Ray Optics (CXRO)

    DOE Data Explorer

    Henke, B.L.; Gullikson, E.M.; Davis, J.C.

    The primary interactions of low-energy x-rays within condensed matter, viz. photoabsorption and coherent scattering, are described for photon energies outside the absorption threshold regions by using atomic scattering factors. The atomic scattering factors may be accurately determined from the atomic photoabsorption cross sections using modified Kramers-Kronig dispersion relations. From a synthesis of the currently available experimental data and recent theoretical calculations for photoabsorption, the angle-independent, forward-scattering components of the atomic scattering factors have been thus semiempirically determined and tabulated here for 92 elements and for the region 50-30,000 eV. Atomic scattering factors for all angles of coherent scattering and at the higher photon energies are obtained from these tabulated forward-scattering values by adding a simple angle-dependent form-factor correction. The incoherent scattering contributions that become significant for the light elements at the higher photon energies are similarly determined. The basic x-ray interaction relations that are used in applied x-ray physics are presented here in terms of the atomic scattering factors. The bulk optical constants are also related to the atomic scattering factors. These atomic and optical relations are applied to the detailed calculation of the reflectivity characteristics of a series of practical x-ray mirror, multilayer, and crystal monochromators. Comparisons of the results of this semiempirical,"atom-like", description of x-ray interactions for the low-energy region with those of experiment and ab initio theory are presented.

  6. Refractive lenses for coherent x-ray sources.

    PubMed

    Pantell, R H; Feinstein, J; Beguiristain, H R; Piestrup, M A; Gary, C K; Cremer, J T

    2001-10-01

    Incoherent x rays in the wavelength interval from approximately 0.5-2 A have been focused with refractive lenses. A single lens would have a long focal length because the refractive index of any material is close to unity; but with a stack of N lens elements the focal length is reduced by the factor N, and such a lens is termed a compound refractive lens (CRL). Misalignment of the parabolic lens elements does not alter the focusing properties and results in only a small reduction in transmission. Based on the principle of spontaneous emission amplification in a FEL wiggler, coherent x-ray sources are being developed with wavelengths of 1-1.5 A and source diameters of 50-80 mum; and the CRL can be used to provide a small, intense image. Chromatic aberration increases the image size by an amount comparable with the diffraction-limited size, and so chromatic correction is important. Pulse broadening through the lens that is due to material dispersion is negligible. The performance of a CRL used in conjunction with a coherent source is analyzed by means of the Kirchhoff integral. For typical parameters, intensity gain is 10(5)-10(6), where gain is defined as the intensity ratio in an image plane with and without the lens in place. (There may be some confusion concerning the usage of the word intensity. As employed in this manuscript, intensity, also called irradiance, refers to power per unit area. This is a commonly accepted usage for intensity, although there are places in the literature where the term radiant incidence is reserved for this definition and intensity refers to power per unit solid angle.) The image intensity is maximized when the CRL is placed 100-200 m from the source, and the diameter of the diffraction-limited spot is approximately 0.12 mum. PMID:18364790

  7. X-Ray Spectroscopy Using Low Temperature Detectors

    NASA Technical Reports Server (NTRS)

    Porter, Frederick

    2011-01-01

    After several decades of development, a significant amount of the effort in low temperature detectors (LTDs) is concentrated on deploying real-world experiments. This has resulted from a great deal of basic detector physics performed by several generations of students, post-docs, and researchers. One of the most fruitful applications of LTDs is in non-dispersive x-ray spectroscopy. LTD x-ray spectrometers are broadband, efficient, moderately high-resolution, and can handle moderately high count rates. However, they require significantly more power, mass, and infrastructure compared to traditional solid state x-ray spectrometers, and cannot achieve, at least at low energies, the resolving powers achieved with dispersive spectrometers. In several fields, however, LTDs have or will make a significant contribution. In this review, we will discuss x-ray spectroscopy in general, the fields of science where LTDs are making a significant impact, and some of the current and near-term LTD spectrometers.

  8. X-ray diagnostics for TFTR

    SciTech Connect

    von Goeler, S.; Hill, K.W.; Bitter, M.

    1982-12-01

    A short description of the x-ray diagnostic preparation for the TFTR tokamak is given. The x-ray equipment consists of the limiter x-ray monitoring system, the soft x-ray pulse-height-analysis-system, the soft x-ray imaging system and the x-ray crystal spectrometer. Particular attention is given to the radiation protection of the x-ray systems from the neutron environment.

  9. Compositional Studies of InGaN Epilayers and Magnesium-doped GaN Grown by MOVPE, Using Wavelength Dispersive X-ray Spectrometry

    E-print Network

    Strathclyde, University of

    ] in Mg:GaN is secondary ion mass (SIMS) spectroscopy, which is both destructive and reliant on custom ion-implanted procedures InxGa1-xN and Mg:GaN samples were grown on sapphire (0001) substrates, under conditions producing respectively. Procedures for growth initiation on sapphire, heteroepitaxial growth of ~1 µm undoped GaN layers

  10. Field-emission scanning electron microscopy and energy-dispersive x-ray analysis to understand the role of tannin-based dyes in the degradation of historical wool textiles.

    PubMed

    Restivo, Annalaura; Degano, Ilaria; Ribechini, Erika; Pérez-Arantegui, Josefina; Colombini, Maria Perla

    2014-10-01

    An innovative approach, combining field-emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy (EDX) analysis, is presented to investigate the degradation mechanisms affecting tannin-dyed wool. In fact, tannin-dyed textiles are more sensitive to degradation then those dyed with other dyestuffs, even in the same conservation conditions. FESEM-EDX was first used to study a set of 48 wool specimens (artificially aged) dyed with several raw materials and mordants, and prepared according to historical dyeing recipes. EDX analysis was performed on the surface of wool threads and on their cross-sections. In addition, in order to validate the model formulated by the analysis of reference materials, several samples collected from historical and archaeological textiles were subjected to FESEM-EDX analysis. FESEM-EDX investigations enabled us to reveal the correlation between elemental composition and morphological changes. In addition, aging processes were clarified by studying changes in the elemental composition of wool from the protective cuticle to the fiber core in cross-sections. Morphological and elemental analysis of wool specimens and of archaeological and historical textiles showed that the presence of tannins increases wool damage, primarily by causing a sulfur decrease and fiber oxidation. PMID:24983911

  11. Comparison of X-ray Powder Diffraction and Solid-State Nuclear Magnetic Resonance in Estimating Crystalline Fraction of Tacrolimus in Sustained-Release Amorphous Solid Dispersion and Development of Discriminating Dissolution Method.

    PubMed

    Rahman, Ziyaur; Bykadi, Srikant; Siddiqui, Akhtar; Khan, Mansoor A

    2015-05-01

    The focus of present investigation was to explore X-ray powder diffraction (XRPD) and solid-state nuclear magnetic resonance (ssNMR) techniques for amorphous and crystalline tacrolimus quantification in the sustained-release amorphous solid dispersion (ASD), and to propose discriminating dissolution method that can detect crystalline drug. The ASD and crystalline physical mixture was mixed in various proportions to make sample matrices containing 0%-100% crystalline-amorphous tacrolimus. Partial-least-square regression and principle component regression were applied to the spectral data. Dissolution of the ASD in the US FDA recommended dissolution medium with and without surfactant was performed. R(2) > 0.99 and slope was close to one for all the models. Root-mean-square of prediction, standard error of prediction, and bias were higher in ssNMR-based models when compared with XRPD data models. Dissolution of the ASD decreased with an increase in the crystalline tacrolimus in the formulations. Furthermore, detection of crystalline tacrolimus in the ASD was progressively masked with an increase in the surfactant level in the dissolution medium. XRPD and ssNMR can be used equally to quantitate the crystalline and amorphous fraction of tacrolimus in the ASD with good accuracy; however, ssNMR data collection time is excessively long, and minimum surfactant level in the dissolution medium maximizes detection of crystalline reversion in the formulation. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:1777-1786, 2015. PMID:25753829

  12. The use of combined three-dimensional electron backscatter diffraction and energy dispersive X-ray analysis to assess the characteristics of the gamma/gamma-prime microstructure in alloy 720Li.

    PubMed

    Child, D J; West, G D; Thomson, R C

    2012-03-01

    Multiple three-dimensional reconstructions of a ?/?' phase structure in Alloy 720Li have been carried out by employing a serial milling technique with simultaneous electron backscatter diffraction (EBSD) and energy dispersive x-ray (EDX) analysis data collection. Combining EBSD data with EDX is critical in obtaining maps to distinguish between the chemically differing, but crystallographically similar ? and ?' phases present in the alloy studied. EDX is shown to allow the differentiation of ? and ?' phases, with EBSD providing increased grain shape accuracy. The combination of data sources also allowed identification of coherent ?/?' phase interfaces that would not be identified using solely EBSD or EDX. The study identifies a region of grain banding within the alloy, which provides the basis for a three-dimensional comparison and discussion of ?' phase size between coarse and fine grain regions, whilst also identifying coherent ?' phase interfaces, possible only using both EDX and EBSD systems simultaneously. The majority of the ?' phase lies in the range of 1-10 ?m in non-banded regions, with a detectable particle size limit of 500 nm being established. The validity of the reconstruction has been demonstrated using an electron interaction volumes model, and an assessment of the validity of EBSD and EDX data sources is discussed showing ?' phase connectivity in all dimensions. PMID:22343666

  13. Analysis of particles produced during airbag deployment by scanning electron microscopy with energy dispersive x-ray spectroscopy and their deposition on surrounding surfaces: a mid-research summary

    NASA Astrophysics Data System (ADS)

    Wyatt, J. Matney

    2011-06-01

    Airbags can be encountered in forensic work when investigating a car crash and are typically constructed with primerlike material to begin the deployment apparatus. The mechanisms of airbag deployment can produce particles ideal for scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS) analysis. A recent study published by Berk studied airbags with vents and showed that it is possible for particles generated from the deployment of these airbags to deposit on surfaces in the vehicle as the airbags deflate.1 Another paper published by Berk reported particles similar in morphology and composition to primer gunshot residue (GSR) are produced by side impact airbags.2 This paper's aim will be to show mid-point results of a study still in progress in which non-vented airbags were analyzed to determine if they exhibited the same particle depositing features as their vented airbag counterparts. Further investigation in this study is being performed to find more airbags which produce primer gunshot residue-like particles containing lead, barium, and antimony from airbag deployment. To date, the study has resulted in (1) non-vented airbags exhibiting deposition of particles suitable for SEM/EDS analysis and (2) no gunshot residue-like particles being detected from the airbag residues studied thus far.

  14. P-V-T equation of state of molybdenite (MoS2) by a diamond anvil cell and in situ synchrotron angle-dispersive X-ray diffraction

    NASA Astrophysics Data System (ADS)

    Fan, Dawei; Xu, Jingui; Ma, Maining; Liu, Jing; Xie, Hongsen

    2014-10-01

    The pressure-volume-temperature (P-V-T) equation of state (EoS) of a natural molybdenite (MoS2) has been measured at high temperature up to 700 K and high pressures up to 18.26 GPa, by using in situ angle-dispersive X-ray diffraction and diamond anvil cell. Analysis of room-temperature P-V data to a third-order Birch-Murnaghan EoS yields: V0=107.0±0.1 Å3, K0=67±2 GPa and K?0=5.0±0.3. With K?0 fixed to 4.0, we obtained: V0=106.7±0.1 Å3 and K0=74.5±0.8 GPa. Fitting of our P-V-T data by means of the high-temperature third order Birch-Murnaghan equations of state, gives the thermoelastic parameters: V0=107.0±0.1 Å3, K0=69±2 GPa, K?0=4.7±0.2, (?K/?T)P=-0.021±0.003 GPa K-1, a=(2.2±0.7)×10-5 K-1 and b=(2.9±0.8)×10-8 K-2. The temperature derivative of the bulk modulus and thermal expansion coefficient of MoS2 are obtained for the first time. Present results are also compared with previously studies determined the elastic properties of MoS2 and WS2.

  15. X-Ray Exam: Ankle

    MedlinePLUS

    ... through them and appear darker. An X-ray technician in the radiology department of a hospital or a health care ... and can't easily be brought to the radiology department, a portable X-ray machine ... rooms. The technician will position your child on the table, and ...

  16. 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.

  17. A Study of Wavelength Calibration of NEWSIPS High-Dispersion Spectra

    E-print Network

    Myron A. Smith

    2001-04-03

    In this study we cross-correlate many IUE echellograms of a variety of stars to evaluate systematic error sources in the wavelength zeropoint of all three cameras. We first evaluated differences between the final archived ("NEWSIPS") and the originally processed ("IUESIPS") spectra. These show a clear time dependence in zeropoint for the SWP camera due to revisions in the IUESIPS wavelength scale. Small IUESIPS - NEWSIPS differences are also found for the LWR camera. We also examined wavelength zeropoint disparities between data obtained both through the small and large entrance apertures and for observations made by different target acquisition modes for faint and bright stars. We found that velocities resulting from these alternative observing modes are nil. For large-aperture observations the dominant error source is the target position placement in the aperture. We searched for spurious trends with time, and found only a suggestion of time trends for faint stars observed with the SWP camera. We also discovered 1-day, +/-3 km/s sinusoidsal patterns in intensive monitoring data which are ascribable to changes in telescope focus resulting from thermal drifts. In the second part of the paper, we measured mean zeropoint errors of NEWSIPS echellogram data against laboratory results by using the GHRS spectral atlas of the 10 Lac. We find that the derived apparent velocity difference for this star is -1 +/-3.5 km/s. Several less precise comparisons lead to similar results. The zeropoints of the NEWSIPS-processed LWP/LWR cameras are evaluated and are also found to be nearly zero (+/-5 km/s) relative to HST atlases of Arcturus and Procyon atlas. These results do not support result by Gonzalez-Riestra et al. that corrections should be introduced to the wavelength scales of various NEWSIPS high-dispersion data products.

  18. X-ray shearing interferometer

    DOEpatents

    Koch, Jeffrey A. (Livermore, CA)

    2003-07-08

    An x-ray interferometer for analyzing high density plasmas and optically opaque materials includes a point-like x-ray source for providing a broadband x-ray source. The x-rays are directed through a target material and then are reflected by a high-quality ellipsoidally-bent imaging crystal to a diffraction grating disposed at 1.times. magnification. A spherically-bent imaging crystal is employed when the x-rays that are incident on the crystal surface are normal to that surface. The diffraction grating produces multiple beams which interfere with one another to produce an interference pattern which contains information about the target. A detector is disposed at the position of the image of the target produced by the interfering beams.

  19. X-Ray Diffraction Apparatus

    NASA Technical Reports Server (NTRS)

    Blake, David F. (Inventor); Bryson, Charles (Inventor); Freund, Friedmann (Inventor)

    1996-01-01

    An x-ray diffraction apparatus for use in analyzing the x-ray diffraction pattern of a sample is introduced. The apparatus includes a beam source for generating a collimated x-ray beam having one or more discrete x-ray energies, a holder for holding the sample to be analyzed in the path of the beam, and a charge-coupled device having an array of pixels for detecting, in one or more selected photon energy ranges, x-ray diffraction photons produced by irradiating such a sample with said beam. The CCD is coupled to an output unit which receives input information relating to the energies of photons striking each pixel in the CCD, and constructs the diffraction pattern of photons within a selected energy range striking the CCD.

  20. Ultrafast x-ray streak camera for use in ultrashort laser-produced plasma research

    Microsoft Academic Search

    Ronnie Shepherd; Rex Booth; Dwight Price; Mark Bowers; Don Swan; Jim Bonlie; Bruce Young; Jim Dunn; Bill White; Richard Stewart

    1995-01-01

    In recent years there has been growing interest in energetic (?100 eV), temporally short (<10 ps) x rays produced by ultrashort laser-produced plasmas. The detection and temporal dispersion of the x rays using x-ray streak cameras has been limited to a resolution of 2 ps, primarily due to the transit time dispersion of the electrons between the photocathode and the

  1. Results of X-ray and optical monitoring of SCO X-1

    NASA Technical Reports Server (NTRS)

    Mook, D. E.; Messina, R. J.; Hiltner, W. A.; Belian, R.; Conner, J.; Evans, W. D.; Strong, I.; Blanco, V.; Hesser, J.; Kunkel, W.

    1974-01-01

    Sco X-1 was monitored at optical and X-ray wavelengths from 1970 April 26 to 1970 May 21. The optical observations were made at six observatories around the world and the X-ray observations were made by the Vela satellites. There was a tendency for the object to show greater variability in X-ray when the object is optically bright. A discussion of the intensity histograms is presented for both the optical and X-ray observations. No evidence for optical or X-ray periodicity was detected.

  2. X-ray Fluorescence (XRF) Assay Using Laser Compton Scattered (LCS) X-rays

    NASA Astrophysics Data System (ADS)

    Naeem, Syed F.; Chouffani, Khalid; Wells, Douglas P.

    2009-03-01

    Laser Compton Scattered (LCS) X-rays are produced as a result of the interaction between accelerated electrons and a laser beam. The yield of LCS X-rays is dependent on the laser power, angle of collision between interacting particles, and the electron linear accelerator's (linac) electron beam energy and its current. One of our research goals at the Idaho Accelerator Center (IAC) focuses on applications such as detection and imaging of fissionable isotopes for nuclear non-proliferation, safeguards and homeland security. Quasi monochromatic LCS X-rays offer much better signal-to-noise ratios for such applications. The energy of LCS X-rays is tunable, that enable element-specific analysis. Two sharp 36.5 keV and 98.4 keV LCS peaks were observed in two separate experiments based on electron beams tuned at 32 MeV and 37 MeV, that were brought in collision with the (Power)peak = 4 GW Nd.YAG laser operating at 532 nm and 266 nm wavelengths. The linac was operating at 60 Hz with an electron beam pulse length of about 50 ps and a peak current of about 7 A. We exploited X-ray fluorescence (XRF) techniques to identify elemental K?1, K?2, and K?1 lines in a high-purity germanium (HPGe) detector, with a 0.5 mm thick Beryllium (Be) absorbing layer, emitted from tin (Sn), cadmium (Cd), silver (Ag), gold (Au), and lead (Pb) foils with thicknesses ranging from 25-500 ?m, following absorption of 36.1 keV and 98.4 keV LCS X-rays. These reference foils were used for the proof of principle, and some have atomic numbers near to that of relevant fission products.

  3. Swift X-Ray Telescope Observations of Galactic Transients

    SciTech Connect

    Kennea, Jamie A. [Department of Astronomy and Astrophysics, 525 Davey Lab, Pennsylvania State University, University Park, PA 16801 (United States)

    2006-06-09

    The Swift Gamma Ray Burst Explorer is a multi wavelength satellite mission dedicated to detection and follow-up of Gamma-Ray Bursts. Swift is comprised of three instruments, a Gamma-Ray detector (BAT), X-ray telescope (XRT) and UV/Optical telescope (UVOT). Swift is able to react with a fast response to both on-board detected transient events, and events discovered by other missions. This rapid response capability makes it an excellent platform for performing time-critical X-ray transients. The Swift X-Ray Telescope (XRT) is able to perform imaging observations of X-ray transients and obtain localizations to {approx}3.5 arc-second accuracy, aiding optical identification with ground based optical and IR follow-ups. We present an account of the operations of the Swift telescope in response to X-ray transients, particularly focusing on XRT observations, and present some results of X-ray monitoring of X-ray Transients with the XRT.

  4. The Distance and Mass of the Galaxy Cluster Abell 1995 Derived From Sunyaev-Zel'dovich Effect and X-Ray Measurements

    NASA Technical Reports Server (NTRS)

    Patel, Sandeep K.; Joy, Marshall; Carlstrom, John E.; Holder, Gilbert P.; Reese, Erik D.; Gomez, Percy L.; Hughes, John P.; Grego, Laura; Holzapfel, William L.

    2000-01-01

    We present multi-wavelength observations of the Abell 1995 galaxy cluster. From analysis of x-ray spectroscopy and imaging data we derive the electron temperature, cluster core radius, and central electron number density. Using optical spectroscopy of 15 cluster members, we derive an accurate cluster redshift and velocity dispersion. Finally, the interferometric imaging of the SZE toward Abell 1995 at 28.5 GHz provides a measure of the integrated pressure through the cluster.

  5. X-ray observations of ultraluminous X-ray sources

    E-print Network

    T. P. Roberts

    2007-06-18

    Ultraluminous X-ray sources (ULXs) are amongst the most intriguing of X-ray source classes. Their extreme luminosities - greater than 10^39 erg/s in the 0.3 - 10 keV band alone - suggest either the presence of black holes larger than those regularly encountered in our own Galaxy (the Galactic centre excepted), or sources apparently radiating well above the Eddington limit. We review the insights afforded us by studies of their X-ray emission, focussing on what this reveals about the underlying compact object. In particular, we discuss recent deep observations of ULXs by the XMM-Newton observatory, and how the unprecedented data quality provided by this mission is starting to discriminate between the different physical models for these extraordinary X-ray emitters.

  6. The X-ray Fluorescence Microscopy Beamline at the Australian Synchrotron

    NASA Astrophysics Data System (ADS)

    Paterson, D.; de Jonge, M. D.; Howard, D. L.; Lewis, W.; McKinlay, J.; Starritt, A.; Kusel, M.; Ryan, C. G.; Kirkham, R.; Moorhead, G.; Siddons, D. P.

    2011-09-01

    A hard x-ray micro-nanoprobe has commenced operation at the Australian Synchrotron providing versatile x-ray fluorescence microscopy across an incident energy range from 4 to 25 keV. Two x-ray probes are used to collect ?-XRF and ?-XANES for elemental and chemical microanalysis: a Kirkpatrick-Baez mirror microprobe for micron resolution studies and a Fresnel zone plate nanoprobe capable of 60-nm resolution. Some unique aspects of the beamline design and operation are discussed. An advanced energy dispersive x-ray fluorescence detection scheme named Maia has been developed for the beamline, which enables ultrafast x-ray fluorescence microscopy.

  7. High-energy X-ray detection by hafnium-doped organic-inorganic hybrid scintillators prepared by sol-gel method

    SciTech Connect

    Sun, Yan; Koshimizu, Masanori, E-mail: koshi@qpc.che.tohoku.ac.jp; Yahaba, Natsuna; Asai, Keisuke [Department of Applied Chemistry, Graduate School of Engineering, Tohoku University, Sendai 980-8579 (Japan); Nishikido, Fumihiko [Molecular Imaging Center, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-8555 (Japan); Kishimoto, Shunji [Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Haruki, Rie [Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirane, Shirakata, Tokai, Ibaraki 319-1195 (Japan)

    2014-04-28

    With the aim of enhancing the efficiency with which plastic scintillators detect high-energy X-rays, hafnium-doped organic-inorganic hybrid scintillators were fabricated via a sol-gel method. Transmission electron microscopy of sampled material reveals the presence of Hf{sub x}Si{sub 1?x}O{sub 2} nanoparticles, dispersed in a polymer matrix that constitutes the active material of the X-ray detector. With Hf{sub x}Si{sub 1?x}O{sub 2} nanoparticles incorporated in the polymer matrix, the absorption edge and the luminescence wavelength is shifted, which we attribute to Mie scattering. The detection efficiency for 67.4-keV X-rays in a 0.6-mm-thick piece of this material is two times better than the same thickness of a commercial plastic scintillator-NE142.

  8. X-Ray Imaging System

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The FluoroScan Imaging System is a high resolution, low radiation device for viewing stationary or moving objects. It resulted from NASA technology developed for x-ray astronomy and Goddard application to a low intensity x-ray imaging scope. FlouroScan Imaging Systems, Inc, (formerly HealthMate, Inc.), a NASA licensee, further refined the FluoroScan System. It is used for examining fractures, placement of catheters, and in veterinary medicine. Its major components include an x-ray generator, scintillator, visible light image intensifier and video display. It is small, light and maneuverable.

  9. X-Ray spectroscopy of cooling flows

    NASA Technical Reports Server (NTRS)

    Prestwich, Andrea

    1996-01-01

    Cooling flows in clusters of galaxies occur when the cooling time of the gas is shorter than the age of the cluster; material cools and falls to the center of the cluster potential. Evidence for short X-ray cooling times comes from imaging studies of clusters and X-ray spectroscopy of a few bright clusters. Because the mass accretion rate can be high (a few 100 solar mass units/year) the mass of material accumulated over the lifetime of a cluster can be as high as 10(exp 12) solar mass units. However, there is little evidence for this material at other wavelengths, and the final fate of the accretion material is unknown. X-ray spectra obtained with the Einstein SSS show evidence for absorption; if confirmed this result would imply that the accretion material is in the form of cool dense clouds. However ice on the SSS make these data difficult to interpret. We obtained ASCA spectra of the cooling flow cluster Abell 85. Our primary goals were to search for multi-temperature components that may be indicative of cool gas; search for temperature gradients across the cluster; and look for excess absorption in the cooling region.

  10. The role of EBIT in X-ray laser research

    SciTech Connect

    Nilsen, J

    2007-01-25

    Back in the early 1980's the X-ray laser program required a new level of understanding and measurements of the atomic physics of highly charged ions. The electron-beam ion trap (EBIT) was developed and built at Lawrence Livermore National Laboratory (LLNL) as part of the effort to understand and measure the cross sections and wavelengths of highly charged ions. In this paper we will discuss some of the early history of EBIT and how it was used to help in the development of X-ray lasers. EBIT's capability was unique and we will show some of the experimental results obtained over the years that were done related to X-ray lasers. As X-ray lasers have now become a table-top tool we will show some new areas of research that involve understanding the index of refraction in partially ionized plasmas and suggest new areas where EBIT may be able to contribute.

  11. Tunable dual- and triple-wavelength mode-locked all-normal-dispersion Yb-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Zhu, Xiaojun; Wang, Chinhua; Zhang, Guoan; Xu, Ruji

    2015-01-01

    A tunable dual- and triple-wavelength passively mode-locked ytterbium-doped fiber laser in the all-normal-dispersion regime is reported and demonstrated. Using a phase-shifted long-period fiber grating as an all-fiber format spectral filter in the laser cavity, a self-starting stabilized multi-wavelength mode-locking operation is achieved by nonlinear polarization evolution. The mode-locked multi-wavelength output can be tuned continuously and smoothly over a spectral range of 10 nm using the phase-shifted long-period fiber grating bandpass filter without re-adjusting any elements in the system. It opens a new possibility to achieve tunable and controllable multi-wavelength mode-locked high-energy laser output in the all-normal-dispersion cavity in an all-fiber format.

  12. IUE short-wavelength high-dispersion line list for the symbiotic nova RR Telescopii

    NASA Technical Reports Server (NTRS)

    Aufdenberg, Jason P.

    1993-01-01

    An 820 minute and other long-exposure archival SWP IUE high-dispersion spectra of symbiotic star RR Tel have been combined to form a composite spectrum. In most of these spectra many lines are saturated, but weaker features appear above the continuum. Their wavelengths were measured from the composite spectrum and compared with the line list from a thorough study of RR Tel by Penston et al. (1983). Among the revised line list are 22 new line identifications from ions C III, O I, N I, Mg VI, Si I, S I, S IV, Fe II, and Ni II. N I exists inside RR Tel's H II region and is pumped by the hot component's continuum. The fluxes for all the lines in each of the spectra are presented. All of the observed ions show a secular flux decrease between 1978 and 1988. A list of SWP high-dispersion camera artifacts is also presented. The list was generated by comparing RR Tel spectra to a long-exposure sky flat.

  13. NSLS-II X-Ray Diagnostics Development

    SciTech Connect

    ILINSKI, P.

    2011-03-28

    NSLS-II x-ray diagnostics will provide continuous online data of electron beam dimensions, which will be used to derive electron beam emittance and energy spread. It will also provide information of electron beam tilt for coupling evaluation. X-ray diagnostics will be based on imaging of bending magnet and three-pole wiggler synchrotron radiation sources. Diagnostics from three-pole wiggler source will be used to derive particles energy spread. Beta and dispersion functions will have to be evaluated for emittance and particles energy spread calculations. Due to small vertical source sizes imaging need to be performed in x-ray energy range. X-ray optics with high numerical aperture, such as compound refractive lens, will be used to achieve required spatial resolution. Optical setups with different magnifications in horizontal and vertical directions fill be employed to deal with large aspect ratio of the source. X-ray diagnostics setup will include x-ray imaging optics, monochromatization, x-ray imaging and recording components.

  14. X-ray Weak Broad-line Qquasars: Absorption or Intrinsic X-ray Weakness

    NASA Technical Reports Server (NTRS)

    Mushotzky, Richard (Technical Monitor); Risaliti, Guida

    2005-01-01

    XMM observations of X-ray weak quasars have been performed during 2003 and 2004. The data for all the observations have become available in 2004 (there has been a delay of several months on the initial schedule, due to high background flares which contaminated the observations: as a consequence, most of them had to be rescheduled). We have reduced and analyzed all the data, and obtained interesting scientific results. Out of the eight sources, 4 are confirmed to be extremely X-ray weak, in agreement with the results of previous Chandra observations. 3 sources are confined to be highly variable both in flux (by factor 20-50) and in spectral properties (dramatic changes in spectral index). For both these groups of objects we are completing a publication: 1) For the X-ray weak sources, a paper is submitted with a complete analysis of the X-ray spectra both from Chandra and XMM-Newton, and a comparison with optical and near-IR photometry obtained from all-sky surveys. Possible models for the unusual spectral energy distribution of these sources are also presented. 2) For the variable sources, a paper is being finalized where the X-ray spectra obtained with XMM-Newton are compared with previous X-ray observations and with observations at other wavelengths. It is shown that these sources are high luminosity and extreme cases of the highly variable class of narrow-line Seyfert Is. In order to further understand the nature of these X-ray weak quasars, we submitted proposals for spectroscopy at optical and infrared telescopes. We obtained time at the TNG 4 meter telescope for near-IR observations and at the Hobby-Eberly Telescope for optical high-resolution spectroscopy. These observations have been performed in early 2004. They will complement the XMM data and will lead to understanding of whether the X-ray weakness of these sources is an intrinsic property or is due to absorption by circum-nuclear material. The infrared spectra of the variable sources have been already analyzed and are discussed in the paper by Memola et al. which will be soon submitted.

  15. Broadband optical parametric gain by novel highly nonlinear tellurite hybrid microstructured optical fiber with four zero-dispersion wavelengths

    NASA Astrophysics Data System (ADS)

    Tuan, Tong Hoang; Cheng, Tonglei; Asano, Koji; Duan, Zhongchao; Suzuki, Takenobu; Ohishi, Yasutake

    2014-03-01

    Fiber-optical parametric amplification (FOPA) has been intensively studied and exploited for various interesting applications such as wavelength conversion, wavelength division multiplexing, optical signal processing and so on. However, its efficiency is governed by the fiber nonlinearity and chromatic dispersion. By employing tellurite glass we propose novel highly nonlinear tellurite hybrid microstructured optical fibers (HMOFs) which have nonlinearity of 6642 W-1km-1 and near-zero flattened dispersion profiles from 1.3 to 2.3 ?m with four zero dispersion wavelengths for FOPA applications. The linear phase-mismatch, optical signal gain and gain bandwidth are precisely calculated by using a full propagation constant which includes the contribution of all high-order dispersion parameters. In contrast with silica fibers, the signal gain is shown to be generated in the wavelength regions where ??<-4?P and the parametric gain coefficient g is imaginary. It is shown that the proposed tellurite HMOFs with short fiber length L<90 cm have the gain bandwidth as broad as 760 nm when it is pumped at 1550 nm. The increase in pump power from 1 to 4 W not only increases the signal gain but also broadens the FOPA gain bandwidth. At 1700-nm pump wavelength, the signal gain larger than 14 dB is obtained over a very broad gain bandwidth of 1200 nm (from 1290 to 2490 nm). To our best knowledge, it is the first time that highly nonlinear tellurite HMOFs are demonstrated as attractive candidates for high performance of FOPA.

  16. Center for X-Ray Optics, 1992

    SciTech Connect

    Not Available

    1993-08-01

    This report discusses the following topics: Center for X-Ray Optics; Soft X-Ray Imaging wit Zone Plate Lenses; Biological X-Ray microscopy; Extreme Ultraviolet Lithography for Nanoelectronic Pattern Transfer; Multilayer Reflective Optics; EUV/Soft X-ray Reflectometer; Photoemission Microscopy with Reflective Optics; Spectroscopy with Soft X-Rays; Hard X-Ray Microprobe; Coronary Angiography; and Atomic Scattering Factors.

  17. Surface-Enhanced X-Ray Fluorescence

    NASA Technical Reports Server (NTRS)

    Anderson, Mark

    2010-01-01

    Surface-enhanced x-ray fluorescence (SEn-XRF) spectroscopy is a form of surface- enhanced spectroscopy that was conceived as a means of obtaining greater sensitivity in x-ray fluorescence (XRF) spectroscopy. As such, SEn-XRF spectroscopy joins the ranks of such other, longer-wavelength surface-enhanced spectroscopies as those based on surface-enhanced Raman scattering (SERS), surface-enhanced resonance Raman scattering (SERRS), and surfaceenhanced infrared Raman absorption (SEIRA), which have been described in previous NASA Tech Briefs articles. XRF spectroscopy has been used in analytical chemistry for determining the elemental compositions of small samples. XRF spectroscopy is rapid and quantitative and has been applied to a variety of metal and mineralogical samples. The main drawback of XRF spectroscopy as practiced heretofore is that sensitivity has not been as high as required for some applications. In SEn-XRF as in the other surface-enhanced spectroscopies, one exploits several interacting near-field phenomena, occurring on nanotextured surfaces, that give rise to local concentrations of incident far-field illumination. In this case, the far-field illumination comes from an x-ray source. Depending on the chemical composition and the geometry of a given nanotextured surface, these phenomena could include the lightning-rod effect (concentration of electric fields at the sharpest points on needlelike surface features), surface plasmon resonances, and grazing incidence geometric effects. In the far field, the observable effect of these phenomena is an increase in the intensity of the spectrum of interest - in this case, the x-ray fluorescence spectrum of chemical elements of interest that may be present within a surface layer at distances no more than a few nanometers from the surface.

  18. The X-ray cluster Abell 744

    NASA Technical Reports Server (NTRS)

    Kurtz, M. J.; Huchra, J. P.; Beers, T. C.; Geller, M. J.; Gioia, I. M.

    1985-01-01

    X-ray and optical observations of the cluster of galaxies Abell 744 are presented. The X-ray flux (assuming H(0) = 100 km/s per Mpc) is about 9 x 10 to the 42nd erg/s. The X-ray source is extended, but shows no other structure. Photographic photometry (in Kron-Cousins R), calibrated by deep CCD frames, is presented for all galaxies brighter than 19th magnitude within 0.75 Mpc of the cluster center. The luminosity function is normal, and the isopleths show little evidence of substructure near the cluster center. The cluster has a dominant central galaxy, which is classified as a normal brightest-cluster elliptical on the basis of its luminosity profile. New redshifts were obtained for 26 galaxies in the vicinity of the cluster center; 20 appear to be cluster members. The spatial distribution of redshifts is peculiar; the dispersion within the 150 kpc core radius is much greater than outside. Abell 744 is similar to the nearby cluster Abell 1060.

  19. Miniature x-ray source

    DOEpatents

    Trebes, James E. (Livermore, CA); Bell, Perry M. (Tracy, CA); Robinson, Ronald B. (Modesto, CA)

    2000-01-01

    A miniature x-ray source utilizing a hot filament cathode. The source has a millimeter scale size and is capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature source consists of a compact vacuum tube assembly containing the hot filament cathode, an anode, a high voltage feedthru for delivering high voltage to the cathode, a getter for maintaining high vacuum, a connector for initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is fabricated from highly x-ray transparent materials, such as sapphire, diamond, or boron nitride.

  20. Imaging X-ray spectrometer

    NASA Technical Reports Server (NTRS)

    Grant, P. A.; Jackson, J. W., Jr.; Alcorn, G. E.; Marshall, F. E. (inventors)

    1984-01-01

    An X-ray spectrometer for providing imaging and energy resolution of an X-ray source is described. This spectrometer is comprised of a thick silicon wafer having an embedded matrix or grid of aluminum completely through the wafer fabricated, for example, by thermal migration. The aluminum matrix defines the walls of a rectangular array of silicon X-ray detector cells or pixels. A thermally diffused aluminum electrode is also formed centrally through each of the silicon cells with biasing means being connected to the aluminum cell walls and causes lateral charge carrier depletion between the cell walls so that incident X-ray energy causes a photoelectric reaction within the silicon producing collectible charge carriers in the form of electrons which are collected and used for imaging.

  1. Long-term optical/X-ray correlations in LMXBs

    NASA Astrophysics Data System (ADS)

    Russell, David

    We have been monitoring the long-term variability of ~30 low-mass X-ray binaries at optical wavelengths with the two 2-m Faulkes Telescopes. With six to eight years of light curves in several filters for most sources, the data provide a rich database of accretion history in samples of transient, quiescent and persistently accreting LMXBs. Here, we correlate the long-term optical evolution (on week to years timescales) of LMXBs with the hard X-ray flux evolution from Swift BAT, RXTE and INTEGRAL. For black hole LMXBs in the hard state, the optical and X-ray fluxes are highly correlated. In some sources, the clear hard X-ray drop/rise over the hard-to-soft/soft-to-hard state transition is replicated (to a lesser extent) in the optical light curves, and are associated with optical colour changes. Lags between optical and X-ray fluxes are apparent, in both the timing of the peak fluxes (e.g. the optical peak of some outbursts occur several days later than the hard X-ray flux peak) and the drop/rises over state transitions. Optical/X-ray cross-correlations have revealed X-ray lags of several days in some persistent sources, which are likely to represent the viscous timescale of the accretion disc. We demonstrate how the properties of the correlations (correlation index values, lag timescales, dependency on spectral state) can be used to infer the optical emission mechanisms. High amplitude optical drop/rises over state transitions are associated with synchrotron emission from jets, and we discuss whether the same is seen in transient, state changing neutron star LMXBs. We also search for optical correlations to the long-term (hundreds of days) X-ray variability timescales seen in some LMXBs.

  2. Simultaneous X-ray and optical observations of the flaring X-ray source, Aquila A-1

    NASA Technical Reports Server (NTRS)

    Bowyer, C. S.; Charles, P. A.

    1979-01-01

    During the summer of 1978 the recurrent transient X-ray source, Aquila X-1, underwent its first major outburst in two years. The results of extensive observations at X-ray and optical wavelengths throughout this event, which lasted for approximately two months are presented. The peak X-ray luminosity was approximately 1.3 times that of the Crab and exhibited spectral dependent flickering on timescales approximately 5 minutes. The observations are interpreted in terms of a standard accretion disk model withparticular emphasis on the similarities to Sco X-1 and other dward X-ray systems, although the transient nature of the system remains unexplained. It was found that Aquila X-1 can be described adequately by the semi-detached Roche lobe model and yields a mass ratio of less than or approximate to 3.5.

  3. Conservation of Moroccan manuscript papers aged 150, 200 and 800 years. Analysis by infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD), and scanning electron microscopy energy dispersive spectrometry (SEM-EDS).

    PubMed

    Hajji, Latifa; Boukir, Abdellatif; Assouik, Jamal; Lakhiari, Hamid; Kerbal, Abdelali; Doumenq, Pierre; Mille, Gilbert; De Carvalho, Maria Luisa

    2015-02-01

    The preservation of manuscripts and archive materials is a serious problem for librarians and restorers. Paper manuscript is subjected to numerous degradation factors affecting their conservation state. This research represents an attempt to evaluate the conservation restoration process applied in Moroccan libraries, especially the alkaline treatment for strengthening weakened paper. In this study, we focused on six samples of degraded and restored paper taken from three different Moroccan manuscripts aged 150, 200 and 800 years. In addition, the Japanese paper used in restoration has been characterized. A modern paper was also analyzed as reference. A three-step analytical methodology based on infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD) and scanning electron microscopy coupled to energy dispersive spectrometry (SEM-EDS) analysis was developed before and after restoration in order to determine the effect of the consolidation treatment on the paper structure. The results obtained by XRD and ATR-FTIR disclosed the presence of barium sulfate (BaSO4) in all restored paper manuscripts. The presence of calcium carbonate (CaCO3) in all considered samples was confirmed by FTIR spectroscopy. The application of de-acidification treatment causes significant changes connected with the increase of intensity mostly in the region 1426 cm(-1), assigned to the asymmetric and symmetric CO stretching mode of calcite, indicating the effectiveness of de-acidification procedure proved by the rise of the alkaline reserve content allowing the long term preservation of paper. Observations performed by SEM magnify the typical paper morphology and the structure of fibbers, highlighting the effect of the restoration process, manifested by the reduction of impurities. PMID:25459630

  4. Conservation of Moroccan manuscript papers aged 150, 200 and 800 years. Analysis by infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD), and scanning electron microscopy energy dispersive spectrometry (SEM-EDS)

    NASA Astrophysics Data System (ADS)

    Hajji, Latifa; Boukir, Abdellatif; Assouik, Jamal; Lakhiari, Hamid; Kerbal, Abdelali; Doumenq, Pierre; Mille, Gilbert; De Carvalho, Maria Luisa

    2015-02-01

    The preservation of manuscripts and archive materials is a serious problem for librarians and restorers. Paper manuscript is subjected to numerous degradation factors affecting their conservation state. This research represents an attempt to evaluate the conservation restoration process applied in Moroccan libraries, especially the alkaline treatment for strengthening weakened paper. In this study, we focused on six samples of degraded and restored paper taken from three different Moroccan manuscripts aged 150, 200 and 800 years. In addition, the Japanese paper used in restoration has been characterized. A modern paper was also analyzed as reference. A three-step analytical methodology based on infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD) and scanning electron microscopy coupled to energy dispersive spectrometry (SEM-EDS) analysis was developed before and after restoration in order to determine the effect of the consolidation treatment on the paper structure. The results obtained by XRD and ATR-FTIR disclosed the presence of barium sulfate (BaSO4) in all restored paper manuscripts. The presence of calcium carbonate (CaCO3) in all considered samples was confirmed by FTIR spectroscopy. The application of de-acidification treatment causes significant changes connected with the increase of intensity mostly in the region 1426 cm-1, assigned to the asymmetric and symmetric Csbnd O stretching mode of calcite, indicating the effectiveness of de-acidification procedure proved by the rise of the alkaline reserve content allowing the long term preservation of paper. Observations performed by SEM magnify the typical paper morphology and the structure of fibbers, highlighting the effect of the restoration process, manifested by the reduction of impurities.

  5. Nanoscale X-ray imaging

    Microsoft Academic Search

    Anne Sakdinawat; David Attwood

    2010-01-01

    Recent years have seen significant progress in the field of soft- and hard-X-ray microscopy, both technically, through developments in source, optics and imaging methodologies, and also scientifically, through a wide range of applications. While an ever-growing community is pursuing the extensive applications of today's available X-ray tools, other groups are investigating improvements in techniques, including new optics, higher spatial resolutions,

  6. X-ray astronomical spectroscopy

    NASA Technical Reports Server (NTRS)

    Holt, S. S.

    1980-01-01

    The current status of the X-ray spectroscopy of celestial X-ray sources, ranging from nearby stars to distant quasars, is reviewed. Particular emphasis is placed on the role of such spectroscopy as a useful and unique tool in the elucidation of the physical parameters of the sources. The spectroscopic analysis of degenerate and nondegenerate stellar systems, galactic clusters and active galactic nuclei, and supernova remnants is discussed.

  7. X-ray computed tomography

    NASA Astrophysics Data System (ADS)

    1993-05-01

    The primary advantage of the X-ray computed tomography (XRCT) NDE method is that features are not superposed in the image, thereby rendering them easier to interpret than radiographic projection images. Industrial XRCT systems, unlike medical diagnostic systems, have no size and dosage constraints; they are accordingly used for systems from the scale of gas turbine blades, with hundreds-of-kV energies, to those of the scale of ICBMs, requiring MV-level X-ray energies.

  8. Picosecond x-ray science

    Microsoft Academic Search

    E. Landahl; D. Reis; J. Wang; L. Young

    2006-01-01

    The report discusses the exciting times for short pulse X-rays and the current users of the technology in the United States. Tracking nuclear motions with X-rays transcends scientific disciplines and includes Biology, Materials Science, Condensed Matter and Chemistry. 1 picosecond accesses many phenomena previously hidden at 100ps. Synchrotron advantage over laser plasma and LCLS is that it's easily tunable. There

  9. Echo Tomography of Reprocessing Sites in X-Ray Binaries

    NASA Technical Reports Server (NTRS)

    Patterson, Joseph; Haswell, Carole

    1998-01-01

    We discovered correlated rapid variability between the optical/UV and X-ray emission for the first time in a soft X-ray transient, GRO J1655-40. Hubble Space Telescope light curves show features similar to those seen by the Rossi X-ray Timing Explorer, but with a mean delay of up to 10 - 20 s. We interpret the correlation as the result of reprocessing of X-rays into optical and UV emission, with a delay owing to finite light travel time; this assumption enables us to perform echo mapping of the system. The time-delay distribution has a mean of 14.6 +/-1.4 s and a dispersion of 10.5+/-1.9 s at binary phase 0.4. This establishes that the reprocessing region is the accretion disk around the compact star, rather than the mass-donating secondary. These results have been published.

  10. Cosmic X-ray physics

    NASA Technical Reports Server (NTRS)

    Mccammon, D.; Cox, D. P.; Kraushaar, W. L.; Sanders, W. T.

    1985-01-01

    A progress report of research activities carried out in the area of cosmic X-ray physics is presented. The Diffuse X-ray Spectrometer DXS which has been flown twice as a rocket payload is described. The observation times proved to be too small for meaningful X-ray data to be obtained. Data collection and reduction activities from the Ultra-Soft X-ray background (UXT) instrument are described. UXT consists of three mechanically-collimated X-ray gas proportional counters with window/filter combinations which allow measurements in three energy bands, Be (80-110 eV), B (90-187 eV), and O (e84-532 eV). The Be band measurements provide an important constraint on local absorption of X-rays from the hot component of the local interstellar medium. Work has also continued on the development of a calorimetric detector for high-resolution spectroscopy in the 0.1 keV - 8keV energy range.

  11. Nanometer x-ray lithography

    NASA Astrophysics Data System (ADS)

    Hartley, Frank T.; Khan Malek, Chantal G.

    1999-10-01

    New developments for x-ray nanomachining include pattern transfer onto non-planar surfaces coated with electrodeposited resists using synchrotron radiation x-rays through extremely high-resolution mask made by chemically assisted focused ion beam lithography. Standard UV photolithographic processes cannot maintain sub-micron definitions over large variation in feature topography. The ability of x-ray printing to pattern thin or thick layers of photoresist with high resolution on non-planar surfaces of large and complex topographies with limited diffraction and scattering effects and no substrate reflection is known and can be exploited for patterning microsystems with non-planar 3D geometries as well as multisided and multilayered substrates. Thin conformal coatings of electro-deposited positive and negative tone photoresist have been shown to be x-ray sensitive and accommodate sub-micro pattern transfer over surface of extreme topographical variations. Chemically assisted focused ion beam selective anisotropic erosion was used to fabricate x-ray masks directly. Masks with feature sizes less than 20 nm through 7 microns of gold were made on bulk silicon substrates and x-ray mask membranes. The technique is also applicable to other high density materials. Such masks enable the primary and secondary patterning and/or 3D machining of Nano-Electro-Mechanical Systems over large depths or complex relief and the patterning of large surface areas with sub-optically dimensioned features.

  12. 100 Gb s?1 coherent dense wavelength division multiplexing system reach extension beyond the limit of electronic dispersion compensation using optical dispersion management

    NASA Astrophysics Data System (ADS)

    Redyuk, A. A.; Nanii, O. E.; Treshchikov, V. N.; Mikhailov, V.; Fedoruk, M. P.

    2014-02-01

    We report numerical investigations of increasing system reach beyond the limit imposed by the state-of-the-art digital signal processing (typically 70 ns nm?1 or 4000 km of standard single mode fiber (SSMF)) by using partial optical dispersion compensation in wavelength division multiplexing 100 Gb s?1 dual polarization quadrature phase shift keying coherent systems. Our numerical model has been verified by the comparison of simulation results with the straight-line real-time transmission experiment. We find that for a legacy fiber-based (non-zero dispersion-shifted fiber) link the transmission distance can be extended to 7000 km with either hybrid spans consisting of SSMF and non-zero dispersion-shifted fiber, or by using partial dispersion compensation employing dispersion-compensating fiber (DCF) with a 1.5 and 0.6 dB optical signal-to-noise ratio (OSNR) margin respectively.

  13. High spectral and spatial resolution X-ray transmission radiography and tomography using a Color X-ray Camera

    PubMed Central

    Boone, Matthieu N.; Garrevoet, Jan; Tack, Pieter; Scharf, Oliver; Cormode, David P.; Van Loo, Denis; Pauwels, Elin; Dierick, Manuel; Vincze, Laszlo; Van Hoorebeke, Luc

    2013-01-01

    High resolution X-ray radiography and computed tomography are excellent techniques for non-destructive characterization of an object under investigation at a spatial resolution in the micrometer range. However, as the image contrast depends on both chemical composition and material density, no chemical information is obtained from this data. Furthermore, lab-based measurements are affected by the polychromatic X-ray beam, which results in beam hardening effects. New types of X-ray detectors which provide spectral information on the measured X-ray beam can help to overcome these limitations. In this paper, an energy dispersive CCD detector with high spectral resolution is characterized for use in high resolution radiography and tomography, where a focus is put on the experimental conditions and requirements of both measurement techniques. PMID:24357889

  14. X-ray spectra of galactic X-ray sources

    NASA Technical Reports Server (NTRS)

    Holt, S. S.

    1980-01-01

    The spectroscopic properties of the various classes of Galactic X-ray sources are discussed, with particular emphasis on binary sources containing an accreting compact object, where post-emission scattering in an accretion disk often prevents the initially produced X-radiation from being observed directly. Theoretical interpretations and X-ray observations are considered for the cataclysmic variables, binary systems with a white dwarf as the compact object and which suffer relatively less from Thomson scattering, and the similar phenomenological spectral characteristics of the bulge sources, including soft transients, bursters and steady X-ray sources with thermal spectra, thought to represent an accreting neutron star, are pointed out. The spectral characteristics of X-ray pulsars in accreting binary systems (rather than the Crab pulsar, which is losing rotational kinetic energy with time) are then presented and interpreted in terms of accretion in the polar regions, and mechanisms for the newly discovered X-ray emission from late-type RS CVn stars are considered.

  15. X-ray Structure of Snow Flea Antifreeze Protein Determined by Racemic Crystallization of Synthetic Protein Enantiomers

    SciTech Connect

    Pentelute, Brad L.; Gates, Zachary P.; Tereshko, Valentina; Dashnau, Jennifer L.; Vanderkooi, Jane M.; Kossiakoff, Anthony A.; Kent, Stephen B.H. (UPENN); (UC)

    2008-08-20

    Chemical protein synthesis and racemic protein crystallization were used to determine the X-ray structure of the snow flea antifreeze protein (sfAFP). Crystal formation from a racemic solution containing equal amounts of the chemically synthesized proteins d-sfAFP and l-sfAFP occurred much more readily than for l-sfAFP alone. More facile crystal formation also occurred from a quasi-racemic mixture of d-sfAFP and l-Se-sfAFP, a chemical protein analogue that contains an additional -SeCH2- moiety at one residue and thus differs slightly from the true enantiomer. Multiple wavelength anomalous dispersion (MAD) phasing from quasi-racemate crystals was then used to determine the X-ray structure of the sfAFP protein molecule. The resulting model was used to solve by molecular replacement the X-ray structure of l-sfAFP to a resolution of 0.98 {angstrom}. The l-sfAFP molecule is made up of six antiparallel left-handed PPII helixes, stacked in two sets of three, to form a compact brick-like structure with one hydrophilic face and one hydrophobic face. This is a novel experimental protein structure and closely resembles a structural model proposed for sfAFP. These results illustrate the utility of total chemical synthesis combined with racemic crystallization and X-ray crystallography for determining the unknown structure of a protein.

  16. X-ray Free-electron Lasers

    SciTech Connect

    Pellegrini, Claudio [UCLA Department of Physics and Astronomy, Los Angeles, CA 90095-1547 (United States)

    2009-09-10

    We review the present status and properties of X-ray free-electron lasers in operation or under construction in the nanometer and sub-nanometer wavelength range, and the novel possibilities they offer for the study of atomic and molecular processes. We also discuss recent developments in relativistic electron beam physics that give us the possibility of designing a new generation of X-ray free-electron lasers that: a. are more compact; b. reduce the radiation pulse duration to one femtosecond or below; c. extend the photon energy to the 50 keV region. These results are obtained by reducing the electron bunch charge while at same time maximizing the beam brightness and reducing the bunch length to a value near or smaller than the free-electron laser cooperation length. In the last case the radiation pulse is fully coherent in the longitudinal and transverse space. The increase in beam brightness can also be used to reduce the beam energy needed for a given radiation wavelength, when, at the same time, the undulator period is reduced. The simultaneous decrease in beam energy and undulator period leads to a more compact free-electron laser, while the high beam brightness reduces the gain length and increases the coherent radiation intensity.

  17. Evaluation of the gas puff z pinch as an x-ray lithography and microscopy source

    Microsoft Academic Search

    J. Bailey; Y. Ettinger; A. Fisher; R. Feder

    1982-01-01

    Soft x rays (100–10 000 eV), due to their short wavelength (0.1–10 nm) can play an important role in high resolution microscopy and lithography. The gas puff Z pinch is an intense source of soft x rays. Calorimeter and x ray diode measurements showed that 10% of the stored electrical energy was converted to radiation in the range of 1–10

  18. TEM (transmission electron microscopy) and x-ray analysis of multilayer mirrors and beamsplitters

    Microsoft Academic Search

    D. G. Stearns; N. M. Ceglio; A. M. Hawryluk; M. B. Stearns; A. K. Petford-Long; C. H. Chang; K. Danzmann; M. Kuhne; P. Muller; B. Wende

    1986-01-01

    Recent advances in the development of lasers at soft x-ray wavelengths has spurred increasing interest in the production of cavity components using multilayer technology. We have established a comprehensive capability to design, fabricate, and characterize multilayer x-ray optics directed towards the goal of building the first x-ray laser cavity. High quality multilayer structures have been fabricated using magnetron sputtering. In

  19. An X-ray emitting bubble in the CEP OB3 association

    NASA Astrophysics Data System (ADS)

    Fabian, A. C.; Stewart, G. C.

    1983-02-01

    The authors report the discovery of a region of extended X-ray emission in the young star association Cep OB3 and its H II region S155. The X-ray luminosity of 2 × 1032 erg s-1 is probably due to a bubble of hot gas formed by the winds of the early-type stars which were not individually detected. This is the first evidence for such a bubble at X-ray wavelengths.

  20. Multidisciplinary research in the space sciences. Scope B: Experimental X-ray astronomy

    NASA Technical Reports Server (NTRS)

    Novick, R.

    1973-01-01

    A research program to design and develop instruments suitable for rocket-borne X-ray astronomy experiments is discussed. Successful designs that were implemented are summarized. The designs include the following: (1) a large area modular X-ray focusing system, (2) incoherent scattering polarimeters, (3) Bragg crystal spectrometers and polarimeters, and (4) a focusing collector for long wavelength. The applications of these instruments to the observation of X-ray sources in rocket-borne experiments are analyzed.

  1. Wavelength dispersion of the local field intensity in silver-gold nanocages.

    PubMed

    Pilot, R; Zoppi, A; Trigari, S; Deepak, F L; Giorgetti, E; Bozio, R

    2015-03-01

    This study provides a combined theoretical and experimental analysis of the far-field (extinction) and of the near-field (SERS enhancement) spectral distribution in hollow nanoparticles, that is, silver-gold nanocages (NCs). Chitosan protected NCs have been synthesized by a galvanic replacement-based procedure: their morphological properties and chemical composition have been characterized by TEM, STEM and ICP. NCs were then functionalized with a thiolated organic dye prior to carrying out SERS measurements. Finite Element Method simulations of a single NC have shown that the field enhancement at the excitation wavelength follows the same spectral dependence as the extinction spectrum and, consequently, the SERS enhancement profile, as a function of the excitation wavelength, peaks at higher energy with respect to extinction. The simulated extinction is remarkably narrower than the experimental spectrum of NCs in solution, indicating that the colloidal sample is substantially polydispersed. However, a simple qualitative model that we have developed would suggest that the SERS enhancement profile is blue-shifted with respect to the extinction in the presence of polydispersivity as well. In addition, NC dimers have been simulated: both their extinction and near field-spectra shift to the red when the size of the gap is reduced analogous to what happens with dimers of filled spherical nanoparticles (NPs). In addition, simulations also revealed that a NC dimer is only slightly more efficient in amplifying the field with respect to the isolated NC, and this behavior is peculiar to NCs. In fact, filled spherical NP dimers exhibit a remarkably stronger field enhancement with respect to the isolated NP. By means of Wavelength Scanned SERS, we measured the spectral distribution of the local field in a dispersion of NCs. We observed experimentally that the local field is distributed in the same spectral region as the extinction and that the absolute value of the SERS enhancement factor maintains a low value throughout the range explored (568-800 nm). We propose that the observed correlation between the SERS profile and the extinction is accidental and originates from the limited increase in amplification provided by NC aggregates with respect to isolated NCs. PMID:25698217

  2. A proposed method to reconstruct the three-dimensional dispersion profile of polymeric fibres based on variable wavelength interferometry.

    PubMed

    Hamza, A A; Sokkar, T Z N; El-Farahaty, K A; Raslan, M I

    2015-02-01

    In this paper, we suggest a modification to the conventional variable wavelength interferometry. This modification allowed us to calculate the dispersion curve of each point inside polymeric fibres instead of calculating the mean dispersion of these fibres. This modified mathematical treatment was used to calculate the three-dimensional dispersion profile of isotactic polypropylene fibres suffering from necking deformation. The different steps of calculating the three-dimensional dispersion profile of the fibre were demonstrated. The application of this modified method revealed the variation of the fibre material dispersion before, inside and after the necking region. In addition, the birefringence profile of the necked isotactic polypropylene was determined using the proposed mathematical treatment. This allowed us to diagnose the interaction of the incident waves with necked polypropylene fibres, which gives extensive information on the orientation of the molecular chains during the formation of the necking phenomenon. PMID:25354726

  3. Recent Progress in X-Ray Laser Research in JAEA

    NASA Astrophysics Data System (ADS)

    Kawachi, T.; Kishimoto, M.; Kado, M.; Hasegawa, N.; Tanaka, M.; Ochi, Y.; Nishikino, M.; Ishino, M.; Imazono, T.; Ohba, T.; Kunieda, Y.; Faenov, A.; Pikuz, T.; Namikawa, K.; Namba, S.; Kato, Y.; Nishimura, H.; Sarukura, N.; Kando, M.; Fukuda, Y.; Kotaki, H.; Pirozhkov, A.; Ma, J.; Sagisaka, A.; Mori, M.; Koga, J.; Bulanov, S.; Daido, H.; Tajima, T.

    Recent progress in x-ray laser (XRL) research in Japan Atomic Energy Agency (JAEA) is reviewed. The repetition-rate of the x-ray laser has been improved from each0 minutes to0 seconds (0.1 Hz) by installing new driver laser, TOPAZ, which allows us to promote the applications of fully spatial coherent3.9 nm laser in the wide variety of research fields such as material science, single-shot x-ray holography and atomic physics. In order to improve the present performance of the x-ray lasers, we have investigated the possibilities of the enhancement of the peak brilliance using v-groove target and the generation of circularly polarized x-ray laser under a strong magnetic field. Towards shorter wavelength x-ray lasers, we have investigated several schemes. One is the use of reflection of the light by relativistic plasma mirror driven by laser-wake-field, and the other is photo-pumping scheme using K? emission from a solid target.

  4. Review of soft x-ray lasers and their applications

    SciTech Connect

    Skinner, C.H.

    1991-03-01

    The emerging technology of soft x-ray lasers is in a transition phase between the first laboratory demonstrations of gain and the acceptance of soft x-ray lasers as practical tools for novel applications. Current research is focused on several fronts. The operational wavelength range has been extended to the water window'', important for applications in the life sciences. Gain has also been generated with substantially simpler technology (such as a 6J laser) and this augurs well for the commercially availability in the near future of soft x-ray lasers for a variety of applications. Advanced soft x-ray laser concepts are being developed from investigations into ultra-high intensity laser/matter interactions. The first paper a brief historical perspective of x-ray microscopy and holography have begun. In this paper a brief historical perspective of x-ray laser development will be followed by a review of recent advances in recombination, collisional and photo-pumped systems and applications. A summary of current gain-length performance achieved in laboratories worldwide is presented. Near term prospects for applications to novel fields are discussed. 81 refs., 9 figs., 1 tab.

  5. Modeling the Radio to X-ray SED of Galaxies

    E-print Network

    L. Silva; G. L. Granato; A. Bressan; P. Panuzzo

    2002-08-17

    Our multi-wavelength model GRASIL for the SED of galaxies is described, in particular the recent extension to the radio and X-ray range. With our model we can study different aspects of galaxy evolution by exploiting all available spectral observations, where different emission components dominate.

  6. Soft X-ray emissions by high current vacuum discharges

    Microsoft Academic Search

    H. Arita; K. Suzuki; Y. Kurosawa; K. Hirasawa

    1989-01-01

    The authors have investigated the vacuum spark, which is utilized in the spectroscopic study of highly charged ions. One merit of the vacuum spark is its ability to produce a stable spot plasma between the electrodes. Another is its flexibility in selection of characteristic X-ray emission wavelengths, because many metals can be used for this purpose. To make a stable

  7. Imaging X-ray Thomson Scattering Spectrometer Design and Demonstration

    SciTech Connect

    Gamboa, E.J. [University of Michigan; Huntington, C.M. [University of Michigan; Trantham, M.R. [University of Michigan; Keiter, P.A [University of Michigan; Drake, R.P. [University of Michigan; Montgomery, David [Los Alamos National Laboratory; Benage, John F. [Los Alamos National Laboratory; Letzring, Samuel A. [Los Alamos National Laboratory

    2012-05-04

    In many laboratory astrophysics experiments, intense laser irradiation creates novel material conditions with large, one-dimensional gradients in the temperature, density, and ionization state. X-ray Thomson scattering is a powerful technique for measuring these plasma parameters. However, the scattered signal has previously been measured with little or no spatial resolution, which limits the ability to diagnose inhomogeneous plasmas. We report on the development of a new imaging x-ray Thomson spectrometer (IXTS) for the Omega laser facility. The diffraction of x-rays from a toroidally-curved crystal creates high-resolution images that are spatially resolved along a one-dimensional profile while spectrally dispersing the radiation. This focusing geometry allows for high brightness while localizing noise sources and improving the linearity of the dispersion. Preliminary results are presented from a scattering experiment that used the IXTS to measure the temperature profile of a shocked carbon foam.

  8. Tokamak physics studies using x-ray diagnostic methods

    SciTech Connect

    Hill, K.W.; Bitter, M.; von Goeler, S.; Beiersdorfer, P.; Fredrickson, E.; Hsuan, H.; McGuire, K.; Sauthoff, N.R.; Sesnic, S.; Stevens, J.E.

    1987-03-01

    X-ray diagnostic measurements have been used in a number of experiments to improve our understanding of important tokamak physics issues. The impurity content in TFTR plasmas, its sources and control have been clarified through soft x-ray pulse-height analysis (PHA) measurements. The dependence of intrinsic impurity concentrations and Z/sub eff/ on electron density, plasma current, limiter material and conditioning, and neutral-beam power have shown that the limiter is an important source of metal impurities. Neoclassical-like impurity peaking following hydrogen pellet injection into Alcator C and a strong effect of impurities on sawtooth behavior were demonstrated by x-ray imaging (XIS) measurements. Rapid inward motion of impurities and continuation of m = 1 activity following an internal disruption were demonstrated with XIS measurements on PLT using injected aluminum to enhance the signals. Ion temperatures up to 12 keV and a toroidal plasma rotation velocity up to 6 x 10/sup 5/ m/s have been measured by an x-ray crystal spectrometer (XCS) with up to 13 MW of 85-keV neutral-beam injection in TFTR. Precise wavelengths and relative intensities of x-ray lines in several helium-like ions and neon-like ions of silver have been measured in TFTR and PLT by the XCS. The data help to identify the important excitation processes predicted in atomic physics. Wavelengths of n = 3 to 2 silver lines of interest for x-ray lasers were measured, and precise instrument calibration techniques were developed. Electron thermal conductivity and sawtooth dynamics have been studied through XIS measurements on TFTR of heat-pulse propagation and compound sawteeth. A non-Maxwellian electron distribution function has been measured, and evidence of the Parail-Pogutse instability identified by hard x-ray PHA measurements on PLT during lower-hybrid current-drive experiments.

  9. The Formation of Compact Groups of Galaxies. II. X-Ray Properties

    Microsoft Academic Search

    Antonaldo Diaferio; Margaret J. Geller; Massimo Ramella

    1995-01-01

    We use N-body\\/hydrodynamic simulations of collapsing rich galaxy groups to predict X-ray properties of compact groups. The model is consistent with the X-ray observations of a few compact groups and naturally explains the correlation between the spiral fraction and the velocity dispersion and crossing time observed in compact groups. The model predicts a correlation between X-ray luminosity and gas temperature

  10. Interbranch transient beating of X-ray intensities in deformed crystals.

    PubMed

    Shevchenko, M

    2010-07-01

    X-ray dynamical diffraction in a deformed crystal is studied using the interbranch resonance concept. It is shown that appreciable beating of the X-ray intensities may be induced by a lattice distortion that produces interbranch transformations of the local dispersion surface. In X-ray plane-wave topography, this effect may be observed as interference fringes arising around the kinematical image of a defect. It is predicted that such interbranch fringes can be induced by edge dislocations. PMID:20555191

  11. X-ray nebular models

    NASA Technical Reports Server (NTRS)

    Kallman, T. R.; Mccray, R.

    1982-01-01

    Theoretical models are presented for the temperature and ionization structure of spherically symmetric, constant density, gaseous nebulae surrounding compact X-ray sources and for the optical, UV, and X-ray spectra emerging from the nebulae. The structure is determined by assuming a local balance between heating and cooling in the gas, and the radiation field is found by solving a simplified equation of transfer. The calculations include an accurate and comprehensive treatment of the atomic processes affecting the state of the gas and the radiation field. The destruction of line radiation during resonance scattering causes models to be significantly hotter and more highly ionized than previous models of the same type. Model results are presented for a wide variety of gas densities and X-ray source spectra, scaling laws which allow these results to be generalized to a wide variety of astrophysical solutions are discussed, and column densities of multiply charged species are tabulated.

  12. Gated monochromatic x-ray imager

    SciTech Connect

    Oertel, J.A.; Archuleta, T.; Clark, L. [and others

    1995-09-01

    We have recently developed a gated monochromatic x-ray imaging diagnostic for the national Inertial-Confinement Fusion (ICF) program. This new imaging system will be one of the primary diagnostics to be utilized on University of Rochester`s Omega laser fusion facility. The new diagnostic is based upon a Kirkpatrick-Baez (KB) microscope dispersed by diffraction crystals, as first described by Marshall and Su. The dispersed images are gated by four individual proximity focused microchannel plates and recorded on film. Spectral coverage is tunable up to 8 keV, spectral resolution has been measured at 20 eV, temporal resolution is 80 ps, and spatial resolution is better than 10 {mu}m.

  13. Highly coherent red-shifted dispersive wave generation around 1.3 ?m for efficient wavelength conversion

    NASA Astrophysics Data System (ADS)

    Li, Xia; Chen, Wei; Xue, Tianfeng; Bi, Wanjun; Gao, Weiqing; Hu, Lili; Liao, Meisong

    2015-03-01

    This research investigates the mechanism of the optical dispersive wave (DW) and proposes a scheme that can realize an efficient wavelength conversion. In an elaborately designed photonic crystal fiber, a readily available ytterbium laser operating at ˜1 ?m can be transferred to the valuable 1.3 ?m wavelength range. A low-order soliton is produced to concentrate the energy of the DW into the target wavelength range and improve the degree of coherence. The input chirp is demonstrated to be a factor that enhances the wavelength conversion efficiency. With a positive initial chirp, 76.6% of the pump energy in the fiber can be transferred into a spectral range between 1.24 and 1.4 ?m. With the use of a grating compressor, it is possible to compress the generated coherent DW of several picoseconds into less than 90 fs.

  14. X-ray exposure sensor and controller

    NASA Technical Reports Server (NTRS)

    Berdahl, C. Martin (Inventor)

    1977-01-01

    An exposure controller for x-ray equipment is provided, which comprises a portable and accurate sensor which can be placed adjacent to and directly beneath the area of interest of an x-ray plate, and which measures the amount of exposure received by that area, and turns off the x-ray equipment when the exposure for the particular area of interest on the x-ray plate reaches the value which provides an optimal x-ray plate.

  15. Three-dimensional manipulation of electron beam phase space for seeding soft x-ray free-electron lasers

    E-print Network

    Feng, Chao; Deng, Haixiao; Zhao, Zhentang

    2014-01-01

    In this letter, a simple technique is proposed to induce strong density modulation into the electron beam with small energy modulation. By using the combination of a transversely dispersed electron beam and a wave-front tilted seed laser, three-dimensional manipulation of the electron beam phase space can be utilized to significantly enhance the micro-bunching of seeded free-electron laser schemes, which will improve the performance and extend the short-wavelength range of a single-stage seeded free-electron laser. Theoretical analysis and numerical simulations demonstrate the capability of the proposed technique in a soft x-ray free-electron laser.

  16. Three-dimensional manipulation of electron beam phase space for seeding soft x-ray free-electron lasers

    NASA Astrophysics Data System (ADS)

    Feng, Chao; Zhang, Tong; Deng, Haixiao; Zhao, Zhentang

    2014-07-01

    In this paper, a simple technique is proposed to induce strong density modulation into the electron beam with small energy modulation. By using the combination of a transversely dispersed electron beam and a wave-front tilted seed laser, three-dimensional manipulation of the electron beam phase space can be utilized to significantly enhance the microbunching of seeded free-electron laser schemes, which will improve the performance and extend the short-wavelength range of a single-stage seeded free-electron laser. Theoretical analysis and numerical simulations demonstrate the capability of the proposed technique in a soft x-ray free-electron laser.

  17. Anomalous lattice expansion in yttria stabilized zirconia under simultaneous applied electric and thermal fields: A time-resolved in situ energy dispersive x-ray diffractometry study with an ultrahigh energy synchrotron probe

    SciTech Connect

    Akdogan, E. K.; Savkl Latin-Small-Letter-Dotless-I y Latin-Small-Letter-Dotless-I ld Latin-Small-Letter-Dotless-I z, I.; Bicer, H.; Paxton, W.; Toksoy, F.; Tsakalakos, T. [Department of Materials Science and Engineering, Rutgers University, Piscataway, New Jersey 08854-8065 (United States)] [Department of Materials Science and Engineering, Rutgers University, Piscataway, New Jersey 08854-8065 (United States); Zhong, Z. [National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973 (United States)] [National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973 (United States)

    2013-06-21

    Nonisothermal densification in 8% yttria doped zirconia (8YSZ) particulate matter of 250 nm median particle size was studied under 215 V/cm dc electric field and 9 Degree-Sign C/min heating rate, using time-resolved in-situ high temperature energy dispersive x-ray diffractometry with a polychromatic 200 keV synchrotron probe. Densification occurred in the 876-905 Degree-Sign C range, which resulted in 97% of the theoretical density. No local melting at particle-particle contacts was observed in scanning electron micrographs, implying densification was due to solid state mass transport processes. The maximum current draw at 905 Degree-Sign C was 3 A, corresponding to instantaneous absorbed power density of 570 W/cm{sup 3}. Densification of 8YSZ was accompanied by anomalous elastic volume expansions of the unit cell by 0.45% and 2.80% at 847 Degree-Sign C and 905 Degree-Sign C, respectively. The anomalous expansion at 905 Degree-Sign C at which maximum densification was observed is characterized by three stages: (I) linear stage, (II) anomalous stage, and (III) anelastic recovery stage. The densification in stage I (184 s) and II (15 s) was completed in 199 s, while anelastic relaxation in stage III lasted 130 s. The residual strains ({epsilon}) at room temperature, as computed from tetragonal (112) and (211) reflections, are {epsilon}{sub (112)} = 0.05% and {epsilon}{sub (211)} = 0.13%, respectively. Time dependence of (211) and (112) peak widths ({beta}) show a decrease with both exhibiting a singularity at 905 Degree-Sign C. An anisotropy in (112) and (211) peak widths of {l_brace} {beta}{sub (112)}/{beta}{sub (211)}{r_brace} = (3:1) magnitude was observed. No phase transformation occurred at 905 Degree-Sign C as verified from diffraction spectra on both sides of the singularity, i.e., the unit cell symmetry remains tetragonal. We attribute the reduction in densification temperature and time to ultrafast ambipolar diffusion of species arising from the superposition of mass fluxes due to Fickian diffusion, thermodiffusion (Soret effect), and electromigration, which in turn are a consequence of a superposition of chemical, temperature, and electrical potential gradients. On the other hand, we propose defect pile-up at particle-particle contacts and subsequent tunneling as a mechanism creating the 'burst-mode' discontinuous densification at the singularities observed at 847 and 905 Degree-Sign C.

  18. Anomalous lattice expansion in yttria stabilized zirconia under simultaneous applied electric and thermal fields: A time-resolved in situ energy dispersive x-ray diffractometry study with an ultrahigh energy synchrotron probe

    NASA Astrophysics Data System (ADS)

    Akdo?an, E. K.; ?avkl?y?ld?z, ?.; Biçer, H.; Paxton, W.; Toksoy, F.; Zhong, Z.; Tsakalakos, T.

    2013-06-01

    Nonisothermal densification in 8% yttria doped zirconia (8YSZ) particulate matter of 250 nm median particle size was studied under 215 V/cm dc electric field and 9 °C/min heating rate, using time-resolved in-situ high temperature energy dispersive x-ray diffractometry with a polychromatic 200 keV synchrotron probe. Densification occurred in the 876-905 °C range, which resulted in 97% of the theoretical density. No local melting at particle-particle contacts was observed in scanning electron micrographs, implying densification was due to solid state mass transport processes. The maximum current draw at 905 °C was 3 A, corresponding to instantaneous absorbed power density of 570 W/cm3. Densification of 8YSZ was accompanied by anomalous elastic volume expansions of the unit cell by 0.45% and 2.80% at 847 °C and 905 °C, respectively. The anomalous expansion at 905 °C at which maximum densification was observed is characterized by three stages: (I) linear stage, (II) anomalous stage, and (III) anelastic recovery stage. The densification in stage I (184 s) and II (15 s) was completed in 199 s, while anelastic relaxation in stage III lasted 130 s. The residual strains (?) at room temperature, as computed from tetragonal (112) and (211) reflections, are ?(112) = 0.05% and ?(211) = 0.13%, respectively. Time dependence of (211) and (112) peak widths (?) show a decrease with both exhibiting a singularity at 905 °C. An anisotropy in (112) and (211) peak widths of {?(112)/?(211)} = (3:1) magnitude was observed. No phase transformation occurred at 905 °C as verified from diffraction spectra on both sides of the singularity, i.e., the unit cell symmetry remains tetragonal. We attribute the reduction in densification temperature and time to ultrafast ambipolar diffusion of species arising from the superposition of mass fluxes due to Fickian diffusion, thermodiffusion (Soret effect), and electromigration, which in turn are a consequence of a superposition of chemical, temperature, and electrical potential gradients. On the other hand, we propose defect pile-up at particle-particle contacts and subsequent tunneling as a mechanism creating the "burst-mode" discontinuous densification at the singularities observed at 847 and 905 °C.

  19. Observational constraints on Be/x-ray binary models

    NASA Astrophysics Data System (ADS)

    Negueruela, Ignacio

    This work deals with the study of Be/X-ray binaries using a multi-wavelength approach and the information we can extract from the observations. It is shown that long-term multi-wavelength monitoring allows us to put constraints on the different models that have been proposed to account for the properties of these systems. Detailed spectroscopic and photometric analysis is used to establish the accurate spectral classification of the optical components of the Be-X-ray binaries 3A 0726-26, 4U 2206+54 and 4U 0115+634. The three objects are shown to be late O-type stars close to the main sequence and presenting emission contamination in most lines in the optical range. The case of 4U 2206+54 is somewhat special, since it does not seem to correspond exactly with any spectral type, arising suspicions of possible binarity of the optical star. The multi-wavelength techniques are then applied to the recurrent transient pulsator 4U 0115+634. Hard X-ray data are presented and their correlation to optical/infrared observations studied. The complex optical/infrared/X-ray behaviour is explained in terms of a series of mass ejection events that lead to the observed outbursts. The degree of variability of the source is shown to be much higher than that of similar objects, which is attributed to the close passage of the neutron star through the circumstellar environment. Spectroscopy in the optical range reveals that the discs surrounding the optical components of the Be/X-ray binaries A 0535+26 and 4U 0115+634 were strongly disturbed in coincidence with major X-ray outbursts. It is shown that observational evidence strongly points to the frequent presence of large-scale perturbances in the circumstellar envelopes of Be/X-ray binaries. Different ways in which these density asymmetries can arise are discussed. The role of the interaction between the neutron star and the circumstellar material is shown to be probably very important. A consistent model explaining the different types of X-ray activity in Be/X-ray binaries is presented.

  20. Miniaturized, High-Speed, Modulated X-Ray Source

    NASA Technical Reports Server (NTRS)

    Gendreau, Keith; Arzoumanian, Zaven; Kenyon, Steve; Spartana, Nick

    2013-01-01

    A low-cost, miniature x-ray source has been developed that can be modulated in intensity from completely off to full intensity on nanosecond timescales. This modulated x-ray source (MXS) has no filaments and is extremely rugged. The energy level of the MXS is adjustable from 0 to more than 100 keV. It can be used as the core of many new devices, providing the first practical, arbitrarily time-variable source of x-rays. The high-speed switching capability and miniature size make possible many new technologies including x-ray-based communication, compact time-resolved x-ray diffraction, novel x-ray fluorescence instruments, and low- and precise-dose medical x-rays. To make x-rays, the usual method is to accelerate electrons into a target material held at a high potential. When the electrons stop in the target, x-rays are produced with a spectrum that is a function of the target material and the energy to which the electrons are accelerated. Most commonly, the electrons come from a hot filament. In the MXS, the electrons start off as optically driven photoelectrons. The modulation of the x-rays is then tied to the modulation of the light that drives the photoelectron source. Much of the recent development has consisted of creating a photoelectrically-driven electron source that is robust, low in cost, and offers high intensity. For robustness, metal photocathodes were adopted, including aluminum and magnesium. Ultraviolet light from 255- to 350-nm LEDs (light emitting diodes) stimulated the photoemissions from these photocathodes with an efficiency that is maximized at the low-wavelength end (255 nm) to a value of roughly 10(exp -4). The MXS units now have much higher brightness, are much smaller, and are made using a number of commercially available components, making them extremely inexpensive. In the latest MXS design, UV efficiency is addressed by using a high-gain electron multiplier. The photocathode is vapor-deposited onto the input cone of a Burle Magnum(TradeMark) multiplier. This system yields an extremely robust photon-driven electron source that can tolerate long, weeks or more, exposure to air with negligible degradation. The package is also small. When combined with the electron target, necessary vacuum fittings, and supporting components (but not including LED electronics or high-voltage sources), the entire modulated x-ray source weighs as little as 158 grams.

  1. The SWIRE/Chandra Survey: The X-ray Sources

    NASA Astrophysics Data System (ADS)

    Wilkes, Belinda J.; Kilgard, Roy; Kim, Dong-Woo; Kim, Minsun; Polletta, Mari; Lonsdale, Carol; Smith, Harding E.; Surace, Jason; Owen, Frazer N.; Franceschini, A.; Siana, Brian; Shupe, David

    2009-12-01

    We report a moderate-depth (70 ks), contiguous 0.7 deg2 Chandra survey in the Lockman Hole Field of the Spitzer/SWIRE Legacy Survey coincident with a completed, ultra-deep VLA survey with deep optical and near-infrared imaging in-hand. The primary motivation is to distinguish starburst galaxies and active galactic nuclei (AGNs), including the significant, highly obscured (log N H > 23) subset. Chandra has detected 775 X-ray sources to a limiting broadband (0.3-8 keV) flux ~4 × 10-16 erg cm-2 s-1. We present the X-ray catalog, fluxes, hardness ratios, and multi-wavelength fluxes. The log N versus log S agrees with those of previous surveys covering similar flux ranges. The Chandra and Spitzer flux limits are well matched: 771 (99%) of the X-ray sources have infrared (IR) or optical counterparts, and 333 have MIPS 24 ?m detections. There are four optical-only X-ray sources and four with no visible optical/IR counterpart. The very deep (~2.7 ?Jy rms) VLA data yield 251 (>4?) radio counterparts, 44% of the X-ray sources in the field. We confirm that the tendency for lower X-ray flux sources to be harder is primarily due to absorption. As expected, there is no correlation between observed IR and X-ray fluxes. Optically bright, type 1, and red AGNs lie in distinct regions of the IR versus X-ray flux plots, demonstrating the wide range of spectral energy distributions in this sample and providing the potential for classification/source selection. Many optically bright sources, which lie outside the AGN region in the optical versus X-ray plots (fr /fx >10), lie inside the region predicted for red AGNs in IR versus X-ray plots, consistent with the presence of an active nucleus. More than 40% of the X-ray sources in the VLA field are radio-loud using the classical definition, RL . The majority of these are red and relatively faint in the optical so that the use of RL to select those AGNs with the strongest radio emission becomes questionable. Using the 24 ?m to radio flux ratio (q 24) instead results in 13 of the 147 AGNs with sufficient data being classified as radio-loud, in good agreement with the ~10% expected for broad-lined AGNs based on optical surveys. We conclude that q 24 is a more reliable indicator of radio-loudness. Use of RL should be confined to the optically selected type 1 AGN.

  2. Compact x-ray source and panel

    DOEpatents

    Sampayon, Stephen E. (Manteca, CA)

    2008-02-12

    A compact, self-contained x-ray source, and a compact x-ray source panel having a plurality of such x-ray sources arranged in a preferably broad-area pixelized array. Each x-ray source includes an electron source for producing an electron beam, an x-ray conversion target, and a multilayer insulator separating the electron source and the x-ray conversion target from each other. The multi-layer insulator preferably has a cylindrical configuration with a plurality of alternating insulator and conductor layers surrounding an acceleration channel leading from the electron source to the x-ray conversion target. A power source is connected to each x-ray source of the array to produce an accelerating gradient between the electron source and x-ray conversion target in any one or more of the x-ray sources independent of other x-ray sources in the array, so as to accelerate an electron beam towards the x-ray conversion target. The multilayer insulator enables relatively short separation distances between the electron source and the x-ray conversion target so that a thin panel is possible for compactness. This is due to the ability of the plurality of alternating insulator and conductor layers of the multilayer insulators to resist surface flashover when sufficiently high acceleration energies necessary for x-ray generation are supplied by the power source to the x-ray sources.

  3. Analysis of the Deformation Behavior of Magnesium-Rare Earth Alloys Mg-2 pct Mn-1 pct Rare Earth and Mg-5 pct Y-4 pct Rare Earth by In Situ Energy-Dispersive X-ray Synchrotron Diffraction and Elasto-Plastic Self-Consistent Modeling

    NASA Astrophysics Data System (ADS)

    Lentz, Martin; Klaus, Manuela; Coelho, Rodrigo S.; Schaefer, Nobert; Schmack, Florian; Reimers, Walter; Clausen, Bjørn

    2014-11-01

    The deformation behavior of the Mg-RE alloys ME21 and WE54 was investigated. Although both alloys contain rare earth elements, which alter and weaken the texture, the flow curves of the alloys deviate significantly, especially in uniaxial compression test. Apart from the higher strength of the WE54 alloy, the compression flow curve does not exhibit the typical sigmoidal shape, which is associated with tension twinning. However, optical microscopy, X-ray texture measurements, and EBSD analysis reveal the activity of tension twinning. The combination of in situ energy-dispersive X-ray synchrotron diffraction and EPSC modeling was used to analyze these differences. The investigation reveals that twin propagation is decelerated in the WE54 alloy, which requires a change of the twinning scheme from the `finite initial fraction' to the `continuity' assumption. Furthermore, an enhanced activity of the < c+ a> pyramidal slip system was observed in case of the WE54 alloy.

  4. Analysis of the Deformation Behavior of Magnesium-Rare Earth Alloys Mg-2 pct Mn-1 pct Rare Earth and Mg-5 pct Y-4 pct Rare Earth by In Situ Energy-Dispersive X-ray Synchrotron Diffraction and Elasto-Plastic Self-Consistent Modeling

    NASA Astrophysics Data System (ADS)

    Lentz, Martin; Klaus, Manuela; Coelho, Rodrigo S.; Schaefer, Nobert; Schmack, Florian; Reimers, Walter; Clausen, Bjørn

    2014-09-01

    The deformation behavior of the Mg-RE alloys ME21 and WE54 was investigated. Although both alloys contain rare earth elements, which alter and weaken the texture, the flow curves of the alloys deviate significantly, especially in uniaxial compression test. Apart from the higher strength of the WE54 alloy, the compression flow curve does not exhibit the typical sigmoidal shape, which is associated with tension twinning. However, optical microscopy, X-ray texture measurements, and EBSD analysis reveal the activity of tension twinning. The combination of in situ energy-dispersive X-ray synchrotron diffraction and EPSC modeling was used to analyze these differences. The investigation reveals that twin propagation is decelerated in the WE54 alloy, which requires a change of the twinning scheme from the `finite initial fraction' to the `continuity' assumption. Furthermore, an enhanced activity of the pyramidal slip system was observed in case of the WE54 alloy.

  5. Fractal characterization of hematite aggregates by X-ray microscopy

    NASA Astrophysics Data System (ADS)

    Thieme, J.; Niemeyer, J.

    1996-12-01

    X-ray microscopy supplies the actual morphology of hematite aggregates in an aqueous dispersion medium. The fractal dimension of hematite aggregates has been determined below and above the critical coagulation concentration. The box-counting method has been used as a morphometric tool. The values obtained are not in accordance with the values produced by numerical approaches.

  6. Development of an x-ray fluorescence microprobe at the National Synchrotron Light Source, Brookhaven National Laboratory: Early results: Comparison with data from other techniques

    SciTech Connect

    Smith, J.V.; Rivers, M.L.; Sutton, S.R.; Jones, K.W.; Hanson, A.L.; Gordon, B.M.

    1986-01-01

    Theoretical predictions for the detection levels in x-ray fluorescence analysis with a synchrotron storage ring are being achieved experimentally at several laboratories. This paper is deliberately restricted to the state of development of the Brookhaven National Laboratory/University of Chicago instruments. Analyses at the parts per million (ppM) level are being made using white light apertured to 20 ..mu..m and an energy dispersive system. This system is particularly useful for elements with Z > 20 in materials dominated by elements with Z < 20. Diffraction causes an interference for crystalline materials. Development of a focusing microprobe for tunable monochromatic x-rays and a wavelength dispersive spectrometer (WDS) is delayed by problems in shaping an 8:1 focusing mirror to the required accuracy. Reconnaissance analyses with a wiggler source on the CHESS synchrotron have been made in the K spectrum up to Z = 80.

  7. Exploring Cosmic X-ray Source Polarization

    NASA Technical Reports Server (NTRS)

    Swank, Jean Hebb; Jahodal, K.; Kallman, T. R.; Kaaret, P.

    2008-01-01

    Cosmic X-ray sources are expected to be polarized, either because of their asymmetry and the role of scattering in their emission or the role of magnetic fields. Polarization at other wavelengths has been useful. X-ray polarization will provide a new handle on black hole parameters, in particular the spin, on accretion flows and outflows, on neutron star spin orientations and emission mechanisms, on the quantum mechanical effects of super-strong magnetic fields of magnetars, and on the structure of supernovae shocks. The proposed Gravity and Extreme Magnetism SMEX (GEMS) will use high efficiency polarimeters behind thin foil mirrors. The statistical sensitivity and control of systematics will allow measurement of polarization fractions as small as 1% from many galactic and extragalactic sources. Targets which should be polarized at the level that GEMS can easily measure include stellar black holes, Seyfert galaxies and quasars, blazars, rotation-powered and accretion-powered pulsars, magnetars, shell supernova remnants and pulsar wind nebulae. The polarimeters are Time Projection Chambers that allow reconstruction of images of photoelectron tracks for 2-10 keV Xrays. They can be deep without sacrificing modulation. These polarimeters do not image the sky, but the telescope point spread function and detector collimation allow structure to be resolved at the 10 arcmin level. Rotation of the spacecraft is not needed for the signal measurement in the Time Projection Chambers, but provides for measurement and correction of systematic errors. It also allows a small Bragg reflection soft X-ray experiment to be included that can be used for isolated neutron stars and blazars.

  8. A soft X-ray spectrometer for diffuse cosmic sources

    NASA Technical Reports Server (NTRS)

    Borken, R. J.; Kraushaar, W. L.

    1976-01-01

    The design of a Bragg crystal spectrometer for the diffuse soft X-ray background is described. The instrument has no moving parts; a 6 degree x 20 degree FWHM field of view; resolution in the range 20-100; and spans wavelength ranges 44-80 A or 13-23 A when lead stearate or KAP crystals are used. If placed on a small spacecraft, integration times of approximately 1000 s will be required to detect the existence of the stronger lines expected in the X-ray background.

  9. Minerals Arranged by X-Ray Powder Diffraction

    NSDL National Science Digital Library

    This directory provides a listing of minerals arranged by Powder X-ray Diffraction (XRD) data . XRD is one of the primary techniques used to examine the physico-chemical make-up of unknown solids, in which a powdered sample is illuminated with X rays of a fixed wavelength and the intensity of the reflected radiation is recorded using a goniometer. Minerals are arranged in increasing order of D1 spacing, with D2 and D3 spacings also provided. Each mineral name is a link to additional information on the mineral.

  10. Phase-matched generation of coherent, ultrafast x-rays using high harmonics

    NASA Astrophysics Data System (ADS)

    Rundquist, Andrew Ralph

    This decade has seen unprecedented progress in the field of extreme non-linear optics. Soft-x-rays are now generated via atomic susceptibilities with visible light. Due to the high intensities needed for these interactions, the recent advances in short pulse technology have pushed this field at an rapid rate. In the last five years, the highest harmonic generated has doubled from 133 to 299, as will be reported in this thesis. In this work I examine the mechanisms of high harmonic generation, showing how I was able to produce coherent ``water window'' x-rays and how we have learned to phasematch harmonics at somewhat longer wavelengths by making use of hollow-core capillary fibers. The future of this field is ``wide open'', but certain paths are clear. Increasing conversion efficiencies by using phase-matching will help make small scale harmonic sources competitive with synchrotron light sources for many applications. Before this work, high harmonic generation was considered to be inherently phase-mismatched. This is due both to the inherent gaussian focusing necessary to achieve the high intensities required, and to the highly dispersive effect of the ionized electrons. However, by using a guiding medium to control the focusing properties and ultrashort pulses to minimize ionization., we have achieved the phase-matched condition. The result is a conversion efficiency 100-1000 times that previously reported at wavelengths between 17 and 35nm.

  11. Hard X-ray Optics Technology Development for Astronomy at the Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Gubarev, Mikhail; Ramsey, Brian; Kilaru, Kiranmayee

    2009-01-01

    Grazing-incidence telescopes based on Wolter 1 geometry have delivered impressive advances in astrophysics at soft-x-ray wavelengths, while the hard xray region remains relatively unexplored at fine angular resolution and high sensitivities. The ability to perform ground-breaking science in the hard-x-ray energy range had been the motivation for technology developments aimed at fabricating low-cost, light-weight, high-quality x-ray mirrors. Grazing-incidence x-ray optics for high-energy astrophysical applications is being developed at MSFC using the electroform-nickel replication process.

  12. Quantitative simultaneous multi-element microprobe analysis using combined wavelength and energy dispersive systems

    NASA Technical Reports Server (NTRS)

    Walter, L. S.; Doan, A. S., Jr.; Wood, F. M., Jr.; Bredekamp, J. H.

    1972-01-01

    A combined WDS-EDS system obviates the severe X-ray peak overlap problems encountered with Na, Mg, Al and Si common to pure EDS systems. By application of easily measured empirical correction factors for pulse pile-up and peak overlaps which are normally observed in the analysis of silicate minerals, the accuracy of analysis is comparable with that expected for WDS electron microprobe analyses. The continuum backgrounds are subtracted for the spectra by a spline fitting technique based on integrated intensities between the peaks. The preprocessed data are then reduced to chemical analyses by existing data reduction programs.

  13. X-ray structure determination of the glycine cleavage system protein H of Mycobacterium tuberculosis using an inverse Compton synchrotron X-ray source.

    PubMed

    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

    2010-03-01

    Structural genomics discovery projects require ready access to both X-ray diffraction and NMR spectroscopy 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 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 multi acre synchrotron facilities for data collection. In this paper we report on the development and use of 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

  14. 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

  15. Lights, X-rays, oxygen!

    PubMed

    Jez, Joseph M; Blankenship, Robert E

    2014-08-14

    Photosystem II uses metal ions to oxidize water to form O2. Two recent papers employ the new technique of serial femtosecond crystallography utilizing X-ray free-electron lasers and nanocrystals to obtain initial structures of intermediate states of photosystem II catalysis at the site of oxygen production. PMID:25126779

  16. Focused X-ray source

    DOEpatents

    Piestrup, Melvin A. (Woodside, CA); Boyers, David G. (Mountain View, CA); Pincus, Cary I. (Sunnyvale, CA); Maccagno, Pierre (Stanford, CA)

    1990-01-01

    An intense, relatively inexpensive X-ray source (as compared to a synchrotron emitter) for technological, scientific, and spectroscopic purposes. A conical radiation pattern produced by a single foil or stack of foils is focused by optics to increase the intensity of the radiation at a distance from the conical radiator.

  17. Stellar X-Ray Polarimetry

    NASA Technical Reports Server (NTRS)

    Swank, J.

    2011-01-01

    Most of the stellar end-state black holes, pulsars, and white dwarfs that are X-ray sources should have polarized X-ray fluxes. The degree will depend on the relative contributions of the unresolved structures. Fluxes from accretion disks and accretion disk corona may be polarized by scattering. Beams and jets may have contributions of polarized emission in strong magnetic fields. The Gravity and Extreme Magnetism Small Explorer (GEMS) will study the effects on polarization of strong gravity of black holes and strong magnetism of neutron stars. Some part of the flux from compact stars accreting from companion stars has been reflected from the companion, its wind, or accretion streams. Polarization of this component is a potential tool for studying the structure of the gas in these binary systems. Polarization due to scattering can also be present in X-ray emission from white dwarf binaries and binary normal stars such as RS CVn stars and colliding wind sources like Eta Car. Normal late type stars may have polarized flux from coronal flares. But X-ray polarization sensitivity is not at the level needed for single early type stars.

  18. X-Ray Diffractive Optics

    NASA Technical Reports Server (NTRS)

    Dennis, Brian; Li, Mary; Skinner, Gerald

    2013-01-01

    X-ray optics were fabricated with the capability of imaging solar x-ray sources with better than 0.1 arcsecond angular resolution, over an order of magnitude finer than is currently possible. Such images would provide a new window into the little-understood energy release and particle acceleration regions in solar flares. They constitute one of the most promising ways to probe these regions in the solar atmosphere with the sensitivity and angular resolution needed to better understand the physical processes involved. A circular slit structure with widths as fine as 0.85 micron etched in a silicon wafer 8 microns thick forms a phase zone plate version of a Fresnel lens capable of focusing approx. =.6 keV x-rays. The focal length of the 3-cm diameter lenses is 100 microns, and the angular resolution capability is better than 0.1 arcsecond. Such phase zone plates were fabricated in Goddard fs Detector Development Lab. (DDL) and tested at the Goddard 600-microns x-ray test facility. The test data verified that the desired angular resolution and throughput efficiency were achieved.

  19. Alpha proton x ray spectrometer

    NASA Technical Reports Server (NTRS)

    Rieder, Rudi; Waeke, H.; Economou, T.

    1994-01-01

    Mars Pathfinder will carry an alpha-proton x ray spectrometer (APX) for the determination of the elemental chemical composition of Martian rocks and soils. The instrument will measure the concentration of all major and some minor elements, including C, N, and O at levels above typically 1 percent.

  20. Interbranch transient beating of X-ray intensities in deformed crystals

    NASA Astrophysics Data System (ADS)

    Shevchenko, M.

    2010-07-01

    An appreciable beating of the X-ray intensities may be induced by a lattice distortion that produces interbranch transformations of the local dispersion surface. In X-ray plane-wave topography, this effect may be observed as interference fringes arising around the kinematical image of a defect.

  1. Wavefront sensing of x-ray telescopes

    NASA Astrophysics Data System (ADS)

    Saha, Timo; Rohrbach, Scott; Hadjimichael, Theo; Zhang, William W.

    2010-07-01

    Phase Retrieval analysis of off-axis or defocused focal-plane data from telescope optics has been proven effective in understanding misalignments and optical aberrations in normal incidence telescopes. The approach is used, e.g., in commissioning of the James Webb Space Telescope (JWST) segmented primary mirror. There is a similar need for evaluating low-order figure errors of grazing incidence mirrors and nested telescope assemblies. When implemented in these systems, phase retrieval does not depend on normal incidence access to each mirror (shell) surface and, therefore, provides an effective means for evaluating nested x-ray telescopes during integration and test. We have applied a well-known phase retrieval algorithm to grazing incidence telescopes. The algorithm uses the Levenberg-Marquardt optimization procedure to perform a non-linear least-squares fit of the telescope Point Spread Function (PSF). The algorithm can also retrieve low order figure errors at visible wavelengths where optical diffraction is the dominant defect in the PSF. In this paper we will present the analytical approach and its implementation for grazing incidence mirrors of the International X-Ray Observatory (IXO). We analyze the effects of low order axial surface errors individually, and in combination on the system PSF at 633 nanometers. We demonstrate via modeling that the wavefront sensing algorithm can recover axial errors (of the grazing incidence mirrors) to a small fraction of the known axial figure errors using simulated PSFs as input data to the algorithm.

  2. Wavefront metrology measurements at SACLA by means of X-ray grating interferometry.

    PubMed

    Kayser, Yves; Rutishauser, Simon; Katayama, Tetsuo; Ohashi, Haruhiko; Kameshima, Takashi; Flechsig, Uwe; Yabashi, Makina; David, Christian

    2014-04-21

    The knowledge of the X-ray wavefront is of importance for many experiments at synchrotron sources and hard X-ray free-electron lasers. We will report on metrology measurements performed at the SACLA X-ray Free Electron Laser by means of grating interferometry which allows for an at-wavelength, in-situ, and single-shot characterization of the X-ray wavefront. At SACLA the grating interferometry technique was used for the study of the X-ray optics installed upstream of the end station, two off-set mirror systems and a double crystal monochromator. The excellent quality of the optical components was confirmed by the experimental results. Consequently grating interferometry presents the ability to support further technical progresses in X-ray mirror manufacturing and mounting. PMID:24787789

  3. Background-reducing X-ray multilayer mirror

    DOEpatents

    Bloch, Jeffrey J. (Los Alamos, NM); Roussel-Dupre', Diane (Los Alamos, NM); Smith, Barham W. (Los Alamos, NM)

    1992-01-01

    Background-reducing x-ray multilayer mirror. A multiple-layer "wavetrap" deposited over the surface of a layered, synthetic-microstructure soft x-ray mirror optimized for reflectivity at chosen wavelengths is disclosed for reducing the reflectivity of undesired, longer wavelength incident radiation incident thereon. In three separate mirror designs employing an alternating molybdenum and silicon layered, mirrored structure overlaid by two layers of a molybdenum/silicon pair anti-reflection coating, reflectivities of near normal incidence 133, 171, and 186 .ANG. wavelengths have been optimized, while that at 304 .ANG. has been minimized. The optimization process involves the choice of materials, the composition of the layer/pairs as well as the number thereof, and the distance therebetween for the mirror, and the simultaneous choice of materials, the composition of the layer/pairs, and their number and distance for the "wavetrap."

  4. The nature of the Vela X-ray "jet"

    E-print Network

    V. V. Gvaramadze

    1999-12-02

    The nature of the Vela X-ray "jet", recently discovered by Markwardt & \\"Ogelman (1995), is examined. It is suggested that the "jet" arises along the interface of domelike deformations of the Rayleigh-Taylor unstable shell of the Vela supernova remnant; thereby the "jet" is interpreted as a part of the general shell of the remnant. The origin of deformations as well as the general structure of the remnant are discussed in the framework of a model based on a cavity explosion of a supernova star. It is suggested that the shell deformations viewed at various angles appear as filamentary structures visible throughout the Vela supernova remnant at radio, optical, and X-ray wavelengths. A possible origin of the nebula of hard X-ray emission detected by Willmore et al. (1992) around the Vela pulsar is proposed.

  5. Spatially resolved X-ray excited optical luminescence

    NASA Astrophysics Data System (ADS)

    Martínez-Criado, G.; Alén, B.; Sans, J. A.; Homs, A.; Kieffer, I.; Tucoulou, R.; Cloetens, P.; Segura-Ruiz, J.; Susini, J.; Yoo, J.; Yi, G.

    2012-08-01

    Spatially resolved luminescence distributions in semiconductor heterostructures were investigated by core level excitation using hard X-ray (sub-) microbeams. Compact and mobile XEOL instruments have been developed and well adapted on the hard X-ray beamline ID22 of the European Synchrotron Radiation Facility for different wavelength collection ranges: UV-VIS and NIR. Linked by multimode optical fibers, their special designs provide precise scanning microscopy and allow easy access for multiple detection modes. Based on the hard X-ray microprobe station of ID22, details of the equipments, spectral data and representative examples are briefly described. Data collections from InAs and InGaN quantum heterostructures support the excellent performance of the optical devices.

  6. Echo-enabled x-ray vortex generation.

    PubMed

    Hemsing, E; Marinelli, A

    2012-11-30

    A technique to generate high-brightness electromagnetic vortices with tunable topological charge at extreme ultraviolet and x-ray wavelengths is described. Based on a modified version of echo-enabled harmonic generation for free-electron lasers, the technique uses two lasers and two chicanes to produce high-harmonic microbunching of a relativistic electron beam with a corkscrew distribution that matches the instantaneous helical phase structure of the x-ray vortex. The strongly correlated electron distribution emerges from an efficient three-dimensional recoherence effect in the echo-enabled harmonic generation transport line and can emit fully coherent vortices in a downstream radiator for access to new research in x-ray science. PMID:23368128

  7. Prospective schemes for next generation x-ray lasers

    NASA Astrophysics Data System (ADS)

    Shlyaptsev, Vyacheslav N.; Rocca, Jorge J.; Grisham, Michael; Avaria, Gonzalo; Tomasel, Fernando; Noy, Aleksandr

    2009-08-01

    Two novel schemes for efficient x-ray laser generation from laser-produced plasma and capillary discharge-driven plasmas are described. The combination of nano-structured targets with the high energy ultrashort pulse lasers can result in the generation of laser-produced plasmas that could lead to high brightness sources of incoherent multi-KeV radiation and x-ray lasers of short pulse duration at shorter wavelengths. The generation of 0.5-1 keV x-ray laser radiation from a Ni-like U plasma created using excitation from a Petawatt laser is analyzed. The efficient excitation of capillary discharge plasmas in micro-capillary discharge channels is discussed.

  8. Picosecond-Resolution Soft-X-Ray Laser Plasma Interferometry

    NASA Astrophysics Data System (ADS)

    Filevich, Jorge; Rocca, Jorge J.; Marconi, Mario C.; Smith, Raymond F.; Dunn, James; Keenan, Roisin; Hunter, James R.; Moon, Stephen J.; Nilsen, Joseph; Ng, Andrew; Shlyaptsev, Vyacheslav N.

    2004-07-01

    We describe a soft-x-ray laser interferometry technique that allows two-dimensional diagnosis of plasma electron density with picosecond time resolution. It consists of the combination of a robust high-throughput amplitude-division interferometer and a 14.7-nm transient-inversion soft-x-ray laser that produces ~5-ps pulses. Because of its picosecond resolution and short-wavelength scalability, this technique has the potential for extending the high inherent precision of soft-x-ray laser interferometry to the study of very dense plasmas of significant fundamental and practical interest, such as those investigated for inertial confinement fusion. Results of its use in the diagnostics of dense large-scale laser-created plasmas are presented.

  9. X-ray emission from Stephan's Quintet and other compact groups

    NASA Technical Reports Server (NTRS)

    Bahcall, N. A.; Harris, D. E.; Rood, H. J.

    1984-01-01

    A search for X-ray emission from five compact groups of galaxies with the Einstein Observatory revealed detections from three groups. Soft, extended X-ray emission was observed in Stephan's Quintet, which is most likely caused by hot intracluster gas. This provides evidence for dynamical interaction among the group galaxies. X-ray emission from the group Arp 330 may also originate in hot intracluster gas. Stephan's Quintet and Arp 330 have the largest velocity dispersions among the groups studied, suggesting a correlation between high velocity and the release (or properties) of hot gas. X-ray emission from Arp 318 may originate in its member galaxies.

  10. Characterization of new hard X-ray cataclysmic variables

    NASA Astrophysics Data System (ADS)

    Bernardini, F.; de Martino, D.; Falanga, M.; Mukai, K.; Matt, G.; Bonnet-Bidaud, J.-M.; Masetti, N.; Mouchet, M.

    2012-06-01

    Aims: We aim at characterizing a sample of nine new hard X-ray selected cataclysmic variable (CVs), to unambiguously identify them as magnetic systems of the intermediate polar (IP) type. Methods: We performed detailed timing and spectral analysis by using X-ray, and simultaneous UV and optical data collected by XMM-Newton, complemented with hard X-ray data provided by INTEGRAL and Swift. The pulse arrival time were used to estimate the orbital periods. The broad band X-ray spectra were fitted using composite models consisting of different absorbing columns and emission components. Results: Strong X-ray pulses at the white dwarf (WD) spin period are detected and found to decrease with energy. Most sources are spin-dominated systems in the X-rays, though four are beat dominated at optical wavelengths. We estimated the orbital period in all system (except for IGR J16500-3307), providing the first estimate for IGR J08390-4833, IGR J18308-1232, and IGR J18173-2509. All X-ray spectra are multi-temperature. V2069 Cyg and RX J0636+3535 posses a soft X-ray optically thick component at kT ~ 80 eV. An intense K? Fe line at 6.4 keV is detected in all sources. An absorption edge at 0.76 keV from OVII is detected in IGR J08390-4833. The WD masses and lower limits to the accretion rates are also estimated. Conclusions: We found all sources to be IPs. IGR J08390-4833, V2069 Cyg, and IGR J16500-3307 are pure disc accretors, while IGR J18308-1232, IGR J1509-6649, IGR J17195-4100, and RX J0636+3535 display a disc-overflow accretion mode. All sources show a temperature gradient in the post-shock regions and a highly absorbed emission from material located in the pre-shock flow which is also responsible for the X-ray pulsations. Reflection at the WD surface is likely the origin of the fluorescent iron line. There is an increasing evidence for the presence of a warm absorber in IPs, a feature that needs future exploration. The addition of two systems to the subgroup of soft X-ray IPs confirms a relatively large (~30%) incidence. Based on observations obtained with XMM-Newton and INTEGRAL, ESA science missions with instruments and contributions directly funded by ESA Member States; and Swift, a NASA science mission with Italian participation.

  11. Characterization of New Hard X-ray Cataclysmic Variables

    NASA Technical Reports Server (NTRS)

    Bernardini, F.; deMartino, D.; Falanga, M.; Mukai, K.; Matt, G.; Bonnet-Bidaud, J.-M.; Masetti, N.; Mouchet, M.

    2012-01-01

    Aims. We aim at characterizing a sample of nine new hard X-ray selected Cataclysmic Variable (CVs), to unambiguously identify them as magnetic systems of the Intermediate Polar (IP) type. Methods. We performed detailed timing and spectral analysis by using X-ray, and simultaneous UV and optical data collected by XMM-Newton, complemented with hard X-ray data provided by INTEGRAL and Swift. The pulse arrival time were used to estimate the orbital periods. The broad band X-ray spectra were fitted using composite models consisting of different absorbing columns and emission components. Results. Strong X-ray pulses at the White Dwarf (WD) spin period are detected and found to decrease with energy. Most sources are spin-dominated systems in the X-rays, though four are beat dominated at optical wavelengths. We estimated the orbital period in all system (except for IGR J16500-3307), providing the first estimate for IGRJ08390-4833, IGRJ18308-1232, and IGR J18173-2509. All X-ray spectra are multi-temperature. V2069 Cyg and RX J0636+3535 poses a soft X-ray optically thick component at kT approx. 80 eV. An intense K (sub alpha) Fe line at 6.4 keV is detected in all sources. An absorption edge at 0.76 keV from OVII is detected in IGR J08390-4833. The WD masses and lower limits to the accretion rates are also estimated. Conclusions. We found all sources to be IPs. IGR J08390-4833, V2069 Cyg, and IGR J16500-3307 are pure disc accretors, while IGR J18308-1232, IGR J1509-6649, IGR J17195-4100, and RX J0636+3535 display a disc-overflow accretion mode. All sources show a temperature gradient in the post-shock regions and a highly absorbed emission from material located in the pre-shock flow which is also responsible for the X-ray pulsations. Reflection at the WD surface is likely the origin of the fluorescent iron line. There is an increasing evidence for the presence of a warm absorber in IPs, a feature that needs future exploration. The addition of two systems to the subgroup of soft X-ray IPs confirms a relatively large ( 30%) incidence.

  12. 160-Gb/s Broadband Wavelength Conversion on Chip Using Dispersion-Engineered Silicon Waveguides

    E-print Network

    Bergman, Keren

    time, have demonstrated wavelength conversion, optical regeneration, amplification, multicasting, a pulsed return-to-zero (RZ) time-division demultiplexer, using organic materials within a silicon slot

  13. Conversion of electrostatic plasma waves into electromagnetic waves - Numerical calculation of the dispersion relation for all wavelengths.

    NASA Technical Reports Server (NTRS)

    Oya, H.

    1971-01-01

    The dispersion curves have been computed for a wide range of wavelengths from electromagnetic waves to electrostatic waves in a magnetoactive warm plasma with a Maxwellian velocity distribution function. The computation was carried out mainly for the perpendicular propagation mode. The upper hybrid resonance is the connection point of the electrostatic waves and the electromagnetic waves. The electrostatic waves not associated with the upper hybrid resonance are subjected to electron cyclotron damping when the wavelength becomes long. Oblique propagation is allowed for the electrostatic waves in a frequency range from the plasma frequency to the upper hybrid resonance frequency in the long-wavelength region where Landau damping can be neglected and where the electrostatic mode smoothly connects to the electromagnetic X-mode. In a slightly inhomogeneous plasma, the Bernstein-mode electrostatic wave can escape by being converted into the O-mode electromagnetic wave; two reflections take place during this escape process.

  14. Ultrahigh resolution photographic films for X-ray\\/EUV\\/FUV astronomy

    Microsoft Academic Search

    Richard B. Hoover; Arthur B. C. Walker Jr.; Craig E. Deforest; Richard Watts; Charles Tarrio

    1993-01-01

    The quest for ultrahigh resolution full-disk images of the sun at soft X-ray\\/EUV\\/FUV wavelengths has increased the demand for photographic films with broad spectral sensitivity, high spatial resolution, and wide dynamic range. These requirements were made more stringent by the recent development of multilayer telescopes and coronagraphs capable of operating at normal incidence at soft X-ray\\/EUV wavelengths. Photographic films are

  15. Cataclysmic variables as probes of x-ray properties of interstellar grains

    SciTech Connect

    Bode, M.F.; Evans, A.; Norwell, G.A.

    1983-01-01

    Interstellar-grain properties have previously been probed at wavelengths ranging from the infrared to the ultraviolet. Recent work by other authors has shown that we may also observe the effects of scattering by such grains at x-ray wavelengths. In this paper we suggest that investigations of the x-ray properties of interstellar grains may profitably be conducted in sight lines to variable sources. Particular emphasis is given in this context to cataclysmic variables and related objects.

  16. Status and Prospects of the X-Ray Astronomy Satellite Astro-H

    NASA Astrophysics Data System (ADS)

    Tsujimoto, M.; Liu, J.

    2015-01-01

    The ASTRO-H satellite is an X-ray astronomy satellite currently planned to be launched in 2015. It is a successor of the series of Japan's X-ray astronomy satellites, and is being developed under an international collaboration with the US, some European countries, and Canada. The satellite carries four scientific payloads: SXS (soft X-ray spectrometer), SXI (soft X-ray imager), HXI (hard X-ray imager), and SGD (soft gamma-ray detector), providing a non-dispersive high-resolution spectroscopic capability with SXS and a wide energy coverage with the four instruments. We present the status of the development and some of the scientific prospects related to the interest of the session, which includes high-resolution X-ray spectroscopy of neutron stars.

  17. Time-resolved near-edge x-ray absorption fine structure spectroscopy on photo-induced phase transitions using a tabletop soft-x-ray spectrometer

    NASA Astrophysics Data System (ADS)

    Grossmann, P.; Rajkovic, I.; Moré, R.; Norpoth, J.; Techert, S.; Jooss, C.; Mann, Klaus

    2012-05-01

    We present a table-top soft-x-ray spectrometer for the wavelength range ? = 1-5 nm based on a stable laser-driven x-ray source, making use of a gas-puff target. With this setup, optical light-pump/soft-x-ray probe near-edge x-ray absorption fine structure (NEXAFS) experiments with a temporal resolution of about 230 ps are feasible. Pump-probe NEXAFS measurements were carried out in the "water-window" region (2.28 nm-4.36 nm) on the manganite Pr0.7Ca0.3MnO3, investigating diminutive changes of the oxygen K edge that derive from an optically induced phase transition. The results show the practicability of the table-top soft-x-ray spectrometer on demanding investigations so far exclusively conducted at synchrotron radiation sources.

  18. X-ray laser related experiments and theory at Princeton

    SciTech Connect

    Suckewer, S.

    1989-04-01

    This paper describes a new system for the development of an x-ray laser in the wavelength region from 5 nm to 1 nm utilizing a Powerful Sub-Picosecond Laser (PP-Laser) of expected peak power up to 0.5 TW in a 300 fs pulse. Soft x-ray spectra generated by the interaction of the PP-Laser beam with different targets are presented and compared to the spectra generated by a much less intense laser beam (20--30 GW). A theoretical model for the interaction of atoms with such a strong laser EM field is also briefly discussed. The development of additional amplifiers for the recombining soft x-ray laser and the design of a cavity are presented from the point of view of applications for x-ray microscopy and microlithography. This overview concludes with the presentation of recent results on the quenching of spontaneous emission radiation and its possible effect on the absolute intensity calibration of soft x-ray spectrometers. 26 refs., 18 figs.

  19. Discovery and development of x-ray diffraction

    NASA Astrophysics Data System (ADS)

    Jeong, Yeuncheol; Yin, Ming; Datta, Timir

    2013-03-01

    In 1912 Max Laue at University of Munich reasoned x-rays to be short wavelength electromagnetic waves and figured interference would occur when scattered off crystals. Arnold Sommerfeld, W. Wien, Ewald and others, raised objections to Laue's idea, but soon Walter Friedrich succeeded in recording x-ray interference patterns off copper sulfate crystals. But the Laue-Ewald's 3-dimensional formula predicted excess spots. Fewer spots were observed. William Lawrence Bragg then 22 year old studying at Cambridge University heard the Munich results from father William Henry Brag, physics professor at Univ of Leeds. Lawrence figured the spots are 2-d interference of x-ray wavelets reflecting off successive atomic planes and derived a simple eponymous equation, the Bragg equation d*sin(theta)= n*lamda. 1913 onward the Braggs dominated the crystallography. Max Laue was awarded the physics Nobel in 1914 and the Braggs shared the same in 1915. Starting with Rontgen's first ever prize in 1901, the importance of x-ray techniques is evident from the four out of a total 16 physics Nobels between 1901-1917. We will outline the historical back ground and importance of x-ray diffraction giving rise to techniques that even in 2013, remain work horses in laboratories all over the globe.

  20. The History of X-ray Free-Electron Lasers

    SciTech Connect

    Pellegrini, C.; /UCLA /SLAC; ,

    2012-06-28

    The successful lasing at the SLAC National Accelerator Laboratory of the Linear Coherent Light Source (LCLS), the first X-ray free-electron laser (X-ray FEL), in the wavelength range 1.5 to 15 {angstrom}, pulse duration of 60 to few femtoseconds, number of coherent photons per pulse from 10{sup 13} to 10{sup 11}, is a landmark event in the development of coherent electromagnetic radiation sources. Until now electrons traversing an undulator magnet in a synchrotron radiation storage ring provided the best X-ray sources. The LCLS has set a new standard, with a peak X-ray brightness higher by ten orders of magnitudes and pulse duration shorter by three orders of magnitudes. LCLS opens a new window in the exploration of matter at the atomic and molecular scales of length and time. Taking a motion picture of chemical processes in a few femtoseconds or less, unraveling the structure and dynamics of complex molecular systems, like proteins, are some of the exciting experiments made possible by LCLS and the other X-ray FELs now being built in Europe and Asia. In this paper, we describe the history of the many theoretical, experimental and technological discoveries and innovations, starting from the 1960s and 1970s, leading to the development of LCLS.