Sample records for x-ray fluorescence atomic

  1. The role of total-reflection X-ray fluorescence in atomic spectroscopy

    NASA Astrophysics Data System (ADS)

    Tölg, G.; Klockenkämper, R.

    1993-02-01

    Total-reflection X-ray fluorescence (TXRF) is a universal and economic method for the simultaneous determination of elements with atomic numbers > 11 down to the lower pg-level. It is a microanalytical tool for the analysis of small sample amounts placed on flat carriers and for contaminations on flat sample surfaces. Analyses of stratified near-surface layers are made possible by varying the incident angle of the primary beam in the region of total-reflection. This non-destructive method is especially suitable for thin layers of a few nanometres, deposited on wafer material although not usable as a microprobe method with a high lateral resolution. Furthermore, depth profiles of biological samples can be recorded by means of microtome sectioning of only a few micrometres, as, for example in the gradient analysis of human organs. In addition to micro- and surface-layer analysis, TXRF is effectively applied to element trace analysis. Homogeneous solutions, for example aqueous solutions, high-purity adds or body fluids, are pipetted onto carriers and, after evaporation, the dry residues are analysed directly down to the pg/ml region. Particularly advantageous is the absence of matrix effects, so that an easy calibration can be carried out by adding a single internal standard element. A digestion or separation step preceding the actual determination becomes necessary if a more complex matrix is to be analysed or especially low detection limits have to be reached. A critical evaluation of the recent developments in atomic spectroscopy places TXRF in a leading position. Its outstanding features compete with those of e.g. electrothermal atomic absorption spectrometry (ETAAS), microwave induced plasma optical emission spectroscopy (MIP-OES) and inductively coupled plasma mass spectrometry (ICP-MS) in the field of micro- and trace analysis and with Rutherford backscattering (RBS) and secondary ion mass spectrometry (SIMS) in the surface-layer analysis.

  2. Fluorescence detection of white-beam X-ray absorption anisotropy: towards element-sensitive projections of local atomic structure

    PubMed Central

    Korecki, P.; Tolkiehn, M.; D?browski, K. M.; Novikov, D. V.

    2011-01-01

    Projections of the atomic structure around Nb atoms in a LiNbO3 single crystal were obtained from a white-beam X-ray absorption anisotropy (XAA) pattern detected using Nb K fluorescence. This kind of anisotropy results from the interference of X-rays inside a sample and, owing to the short coherence length of a white beam, is visible only at small angles around interatomic directions. Consequently, the main features of the recorded XAA corresponded to distorted real-space projections of dense-packed atomic planes and atomic rows. A quantitative analysis of XAA was carried out using a wavelet transform and allowed well resolved projections of Nb atoms to be obtained up to distances of 10?Å. The signal of nearest O atoms was detected indirectly by a comparison with model calculations. The measurement of white-beam XAA using characteristic radiation indicates the possibility of obtaining element-sensitive projections of the local atomic structure in more complex samples. PMID:21997909

  3. Comparison between X-ray fluorescence and inductively coupled plasma atomic emission spectrometry in the analysis of sediment samples

    NASA Astrophysics Data System (ADS)

    Somogyi, Andrea; Braun, Mihály; Posta, József

    1997-11-01

    Two multielemental analytical techniques, X-ray fluorescence analysis (XRF) and inductively coupled plasma atomic emission spectrometry (ICP-AES) were used for the analysis of the elemental composition of sediment samples from a marsh and standard reference materials. The sediment samples were pretreated with different methods which are widely used in practice. A comparison was made not only between the concentrations obtained by the different methods, but also between the statistical conclusions derived from the processing of the experimental results. Good agreement was found for some elements, e.g. Mn, Zn and Sr, while the concentrations and the statistical conclusions were shown to depend on the analytical method used in the case of other elements, e.g. Fe and Zr.

  4. Measurements of K-shell X-ray production cross-sections and fluorescence yields for some elements in the atomic number range 28?Z?40

    NASA Astrophysics Data System (ADS)

    Yilmaz, R.; Tunç, H.; özkartal, A.

    2015-07-01

    K shell X-ray production cross-sections (?K? and ?K?) have been measured for some elements in the atomic number range 28?Z?40. Measurements have been carried out at 16.896 keV excitation energy using secondary source. K X-rays emitted by samples have been counted by a Si(Li) detector with 160 eV resolution at 5.9 keV. The values of K-shell fluorescence yields (?K) have been evaluated for the same elements. The results obtained for K X-ray production cross-sections and fluorescence yields have been compared with the theoretically calculated values and other available semiempirical values.

  5. Identification of steel by X-ray fluorescence analysis with a pyroelectric X-ray generator

    Microsoft Academic Search

    Hiroyuki Ida; Jun Kawai

    2004-01-01

    An application of X-ray fluorescence analysis with a pyroelectric X-ray generator is presented. Steel standard samples were identified by X-ray fluorescence analysis with this novel X-ray generator to check its capability for performing qualitative and quantitative analysis as an X-ray source for X-ray fluorescence spectrometers. Cr, Ni, V, Co, and W were detected in steel standard samples. V and Cr

  6. Comparison of a portable micro-X-ray fluorescence spectrometry with inductively coupled plasma atomic emission spectrometry for the ancient ceramics analysis

    Microsoft Academic Search

    D. N. Papadopoulou; G. A. Zachariadis; A. N. Anthemidis; N. C. Tsirliganis; J. A. Stratis

    2004-01-01

    Two multielement instrumental methods of analysis, micro X-ray fluorescence spectrometry (micro-XRF) and inductively coupled plasma atomic emission spectrometry (ICP-AES) were applied for the analysis of 7th and 5th century B.C. ancient ceramic sherds in order to evaluate the above two methods and to assess the potential to use the current compact and portable micro-XRF instrument for the in situ analysis

  7. Detection of terrestrial radionuclides with X-ray fluorescence analysis.

    PubMed

    Trojek, T; ?echák, T

    2015-06-01

    This paper provides an overview of analytical methods frequently used to identify terrestrial radionuclides in samples. While radioactivity is normally measured through the ionising radiation produced during the spontaneous decay of unstable atoms, selected radionuclides or their chemical elements can be quantified with instrumental techniques based on stimulated emission or counting of atoms. The advantages and disadvantages of these analytical methods are discussed. Particular attention is paid to X-ray fluorescence analysis of materials containing uranium and thorium. It is also possible to determine the area distributions of these chemical elements in samples with the use of scanning X-ray fluorescence systems. PMID:25977354

  8. In Situ Synchrotron Based X-ray Fluorescence and Scattering Measurements During Atomic Layer Deposition: Initial Growth of HfO2 on Si and Ge Substrates

    SciTech Connect

    K Devloo-Casier; J Dendooven; K Ludwig; G Lekens; J DHaen; C Detavernier

    2011-12-31

    The initial growth of HfO{sub 2} was studied by means of synchrotron based in situ x-ray fluorescence (XRF) and grazing incidence small angle x-ray scattering (GISAXS). HfO{sub 2} was deposited by atomic layer deposition (ALD) using tetrakis(ethylmethylamino)hafnium and H{sub 2}O on both oxidized and H-terminated Si and Ge surfaces. XRF quantifies the amount of deposited material during each ALD cycle and shows an inhibition period on H-terminated substrates. No inhibition period is observed on oxidized substrates. The evolution of film roughness was monitored using GISAXS. A correlation is found between the inhibition period and the onset of surface roughness.

  9. 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.

  10. Glancing angle x-ray fluorescence and its application in x-ray technique

    NASA Astrophysics Data System (ADS)

    Dudchik, Yury I.; Komarov, Fadei F.; Konstantinov, Yaroslav A.

    1996-07-01

    Calculation procedures and experimental results form glancing angle x-ray fluorescence from thin films on a flat substrate are presented. A new x-ray tube unit with a super smooth-surface anode and a built-in waveguide collimator is described. The unit makes it possible to obtain narrowly- collimated beams of x-ray radiation with a microfocus line.

  11. In situ synchrotron based x-ray techniques as monitoring tools for atomic layer deposition

    SciTech Connect

    Devloo-Casier, Kilian, E-mail: Kilian.DevlooCasier@Ugent.be; Detavernier, Christophe; Dendooven, Jolien [Department of Solid State Sciences, Ghent University, Krijgslaan 281/S1, B-9000 Ghent (Belgium); Ludwig, Karl F. [Physics Department, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215 (United States)

    2014-01-15

    Atomic layer deposition (ALD) is a thin film deposition technique that has been studied with a variety of in situ techniques. By exploiting the high photon flux and energy tunability of synchrotron based x-rays, a variety of new in situ techniques become available. X-ray reflectivity, grazing incidence small angle x-ray scattering, x-ray diffraction, x-ray fluorescence, x-ray absorption spectroscopy, and x-ray photoelectron spectroscopy are reviewed as possible in situ techniques during ALD. All these techniques are especially sensitive to changes on the (sub-)nanometer scale, allowing a unique insight into different aspects of the ALD growth mechanisms.

  12. X-ray Fluorescence (XRF) Assay Using Laser Compton Scattered (LCS) X-rays

    SciTech Connect

    Naeem, Syed F.; Chouffani, Khalid; Wells, Douglas P. [Idaho State University, Idaho Accelerator Center, Campus Box 8263, Pocatello ID 83209 (United States)

    2009-03-10

    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){sub 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{alpha}{sub 1}, K{alpha}{sub 2}, and K{beta}{sub 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 {mu}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.

  13. 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.

  14. Applications of x rays in art authentication: radiography, x-ray diffraction, and x-ray fluorescence

    Microsoft Academic Search

    Richard Newman

    1998-01-01

    Several techniques involving X-rays are routinely applied in the study of works of art. These include radiography, X-ray diffraction, and X-ray fluorescence (often coupled with an electron beam instrument such as a scanning electron microscope or microprobe). Radiography provides information on condition and previous restorations or repairs. In the case of sculptures, the technique also sheds light on the manufacturing

  15. MESSENGER X-Ray Spectrometer Detection of Electron-induced X-ray Fluorescence from Mercury's Surface

    NASA Astrophysics Data System (ADS)

    Starr, R. D.; Nittler, L. R.; Weider, S. Z.; Rhodes, E. A.; Schriver, D.; Schlemm, C. E., II; Solomon, S. C.

    2011-12-01

    The X-Ray Spectrometer (XRS) onboard the MESSENGER spacecraft measures elemental abundances on the surface of Mercury by detecting fluorescent X-ray emissions induced on the planet's surface by the incident solar X-ray flux. The most prominent fluorescent lines are the K? lines from the elements Mg, Al, Si, S, Ca, Ti, and Fe (1-10 keV). The XRS began orbital observations on 23 March 2011 and has observed X-ray fluorescence from the surface of the planet during both "quiet" Sun and flaring conditions whenever a sunlit portion of Mercury has been within the XRS field of view. XRS can detect the characteristic X-rays of Mg, Al, and Si during quiet-Sun conditions, but solar flares are required to produce measureable signals from the elements of higher atomic number such as S, Ca, Ti, and Fe. Nevertheless, X-ray fluorescence up to the Ca fluorescent line (3.69 keV) has been detected from Mercury's surface at times when the XRS field of view included only unlit portions of the planet or during quiet-Sun illumination. To date, seven such events have been detected and are identified as electron-induced X-ray emission produced by ~1-10 keV electrons interacting with Mercury's surface. Electrons in this energy range were detected by the XRS during the three Mercury flybys, and since the beginning of orbital operations electrons of this same energy range have been detected by XRS during almost every orbit. These electron events last from minutes to tens of minutes. Electron transport models suggest that a large percentage of these quasi-trapped electrons do not complete even a single orbit about Mercury before impacting the surface. Knowledge of the precipitating electron distribution at the planet's surface makes it possible to infer surface composition from the measured fluorescent spectra, providing additional measurement opportunities for the XRS.

  16. Direct extraction of quantitative structural information from x-ray fluorescence holograms using spherical-harmonic analysis

    NASA Astrophysics Data System (ADS)

    Wang, Yuhao; Bai, Jianming; Tyson, Trevor A.

    2012-06-01

    An x-ray fluorescence holograph contains information on both the amplitude and the phase of the x-ray scattering signal from a crystal structure. X-ray fluorescence holography is potentially a technique to directly extract atomic level structure information from crystal samples. We present here a reconstruction algorithm using a spherical-harmonic analysis that significantly improves the structure-resolving power of x-ray fluorescence holography over the widely used multiple energy Barton transform approach. Compared to the direct method for x-ray diffraction, this direct method has the advantages of full model independence and applicability to crystal systems with a large contrast in atomic numbers.

  17. A library for X-ray–matter interaction cross sections for X-ray fluorescence applications

    Microsoft Academic Search

    A. Brunetti; M. Sanchez del Rio; B. Golosio; A. Simionovici; A. Somogyi

    2004-01-01

    Quantitative estimate of elemental composition by spectroscopic and imaging techniques using X-ray fluorescence requires the availability of accurate data of X-ray interaction with matter. Although a wide number of computer codes and data sets are reported in literature, none of them is presented in the form of freely available library functions which can be easily included in software applications for

  18. X-ray scattering in X-ray fluorescence spectra with X-ray tube excitation – Modelling, experiment, and Monte-Carlo simulation

    Microsoft Academic Search

    V.-D. Hodoroaba; M. Radtke; L. Vincze; V. Rackwitz; D. Reuter

    2010-01-01

    X-ray scattering may contribute significantly to the spectral background of X-ray fluorescence (XRF) spectra. Based on metrological measurements carried out with a scanning electron microscope (SEM) having attached a well characterised X-ray source (polychromatic X-ray tube) and a calibrated energy dispersive X-ray spectrometer (EDS) the accuracy of a physical model for X-ray scattering is systematically evaluated for representative samples. The

  19. Development and applications of grazing exit micro X-ray fluorescence instrument using a polycapillary X-ray lens

    Microsoft Academic Search

    T. Emoto; Y. Sato; Y. Konishi; X. Ding; K. Tsuji

    2004-01-01

    A polycapillary X-ray lens is an effective optics to obtain a ?m-size X-ray beam for micro-X-ray fluorescence spectrometry (?-XRF). We developed a ?-XRF instrument using a polycapillary X-ray lens, which also enabled us to perform Grazing Exit ?-XRF (GE-?-XRF). The evaluated diameter of the primary X-ray beam was 48 ?m at the focal distance of the X-ray lens. Use of

  20. X-ray Microprobe for Fluorescence and Diffraction Analysis

    SciTech Connect

    Ice, G.E. (ORNL)

    2005-03-28

    X-ray diffraction (see unit 1.1) and x-ray excited fluorescence analysis are powerful techniques for the nondestructive measurement of crystal structure and chemical composition. X-ray fluorescence analysis is inherently nondestructive with orders of magnitude lower power deposited for the same detectable limit as with fluorescence excited by charged particle probes (Sparks, 1980). X-ray diffraction analysis is sensitive to crystal structure with orders-of-magnitude greater sensitivity to crystallographic strain than electron probes (Rebonato, et al. 1989). When a small-area x-ray microbeam is used as the probe, chemical composition (Z>14), crystal structure, crystalline texture, and crystalline strain distributions can be determined. These distributions can be studied both at the surface of the sample and deep within the sample (Fig. 1). Current state-of-the-art can achieve an {approx}1 mm-D x-ray microprobe and an {approx}0.1 mm-D x-ray microprobe has been demonstrated (Bilderback, et al., 1994). Despite their great chemical and crystallographic sensitivities, x-ray microprobe techniques have until recently been restricted by inefficient x-ray focusing optics and weak x-ray sources; x-ray microbeam analysis was largely superseded by electron techniques in the 50's. However, interest in x-ray microprobe techniques has now been revived (Howells, et al., 1983; Ice & Sparks, 1984; Chevallier, et al., 1997; Riekel 1992; Thompson, el al., 1992; and Making and Using... 1997) by the development of efficient x-ray focusing optics and ultra-high intensity synchrotron x-ray sources (Buras & Tazzari, 1984; Shenoy, et al., 1988). These advances have increased the achievable microbeam flux by more than 11 orders of magnitude (Fig. 2) (Ice, 1997); the flux in a tunable 1 mm-D beam on a 'so called' 3rd-generation synchrotron source such as the APS can exceed the flux in a fixed-energy mm2 beam on a conventional source. These advances make x-ray microfluorescence and x-ray microdiffraction analysis techniques some of the most powerful techniques available for the nondestructive measurement of chemical and crystallographic distributions in materials. This unit reviews the physics, advantages, and scientific applications of hard x-ray (E > 3 keV) microfluorescence and x-ray microdiffraction analysis. Because practical x-ray microbeam instruments are extremely rare, a special emphasis will be placed on instrumentation, accessibility, and experimental needs which justify the use of x-ray microbeam analysis.

  1. 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

    wet-ashing the membrane filter containing the fume followed by atomic absorption spectrophotometry. Although this method is very reliable, it is both time-consuming and destructive in nature. In contrast, x-ray fluorescence spectrometry is a very.... Previous research has shown x-ray fluorescence spectrometry to have the sensitivity necessary for industrial hygiene applications. A portable x-ray fluorescent survey meter was evaluated for analytical performance in a laboratory environment and as a...

  2. Novel parallel vacuum ultra-violet/X-ray fluorescence spectrometer

    NASA Astrophysics Data System (ADS)

    Erko, A.; Firsov, A.; Senf, F.

    2012-01-01

    Novel instrumentation developments in X-ray spectroscopy for parallel spectral measurements with soft X-rays are described. The significant performance improvements are achieved utilising Fresnel diffraction from structures built onto the surface of a total external reflection mirror. An array of reflection zone plates was tested as a wavelength-dispersive fluorescence spectrometer for soft X-rays in the energy range of 100-550 eV.

  3. Fluorescent X-ray transport in microchannel plates

    NASA Astrophysics Data System (ADS)

    Mazuritskiy, M. I.

    2006-12-01

    The X-ray absorption spectra of microchannel plates have been measured at grazing incidence of the primary radiation. The Si L components of X-ray absorption near-edge structure (XANES) spectra exhibit specific features for incident angles below a certain critical value. In order to explain the experimental data, a mechanism of selective X-ray fluorescence transport via microchannels is proposed, which is based on the notion of anomalous dispersion in the vicinity of the Si L absorption edge.

  4. Determination of beryllium by using X-ray fluorescence spectrometry.

    PubMed

    Zawisza, Beata

    2008-03-01

    X-ray fluorescence spectrometry method is subject to certain difficulties and inconveniences for the elements having the atomic number 9 or less. These difficulties become progressively more severe as the atomic number decreases, and are quite serious for beryllium, which is practically indeterminable directly by XRF. Therefore, an indirect determination of beryllium that is based on the evaluation of cobalt in the precipitate is taken into consideration. In the thesis below, there is a description of a new, simple, and precise method by selective precipitation using hexamminecobalt(III) chloride and ammonium carbonate-EDTA solution as a complexing agent for the determining of a trace amount of beryllium using X-ray fluorescence spectrometry. The optimum conditions for [Co(NH(3))(6)][Be(2)(OH)(3)(CO(3))(2)(H(2)O)(2)].(3)H(2)O complex formation were studied. The complex was collected on the membrane filter, and the Co Kalpha line was measured by XRF. The method presents the advantages of the sample preparation and the elimination of the matrix effects due to the thin film obtained. The detection limit of the proposed method is 0.2 mg of beryllium. The method was successfully applied to beryllium determination in copper/ beryllium/cobalt alloys. PMID:18247483

  5. MESSENGER X-Ray Spectrometer Detection of Electron-induced X-ray Fluorescence from Mercury's Surface

    NASA Astrophysics Data System (ADS)

    Starr, R. D.; Schriver, D.; Nittler, L. R.; Weider, S. Z.; Byrne, P. K.; Ho, G. C.; Rhodes, E. A.; Schlemm, C. E.; Solomon, S. C.; Travnicek, P. M.

    2012-12-01

    X-ray emission from solar system bodies has been observed for decades. The surface of planets with no atmosphere may be excited by solar X-rays, solar wind particles (primarily electrons), and ions, producing line emission and bremsstrahlung. Measurement of solar-induced X-ray fluorescence (XRF) from planetary surfaces has been used to infer surface elemental abundances at the Moon and the asteroids 433 Eros and 25143 Itokawa. More recently, the MESSENGER X-Ray Spectrometer (XRS) has reported on Mercury's surface composition derived from measurements of solar-flare-induced XRF. The XRS began orbital observations on 23 March 2011 and has observed X-ray fluorescence from the surface of the planet during both "quiet-Sun" and flaring conditions whenever a sunlit portion of Mercury has been within the XRS field of view. XRS can detect the characteristic X-rays of Mg, Al, and Si during quiet-Sun conditions, but solar flares are required to produce measurable signals from the elements of higher atomic number such as S, Ca, Ti, and Fe. Nevertheless, X-ray fluorescence up to the Ca fluorescent line (3.69 keV) has been detected from Mercury's surface at times when the XRS field of view included only unlit portions of the planet or during quiet-Sun illumination. Many such events have been detected and are identified as electron-induced X-ray emission produced by ~1-10 keV electrons interacting with Mercury's surface. Electrons in this energy range were detected by the XRS during the three Mercury flybys, and since the beginning of orbital operations electrons of this same energy range have been detected by XRS during almost every orbit. These electron events last from minutes to tens of minutes. Electron transport models suggest that a large percentage of these quasi-trapped electrons do not complete even a single drift orbit about Mercury before impacting the surface. Knowledge of the precipitating electron distribution at the planet's surface makes it possible to infer surface composition from the measured fluorescent spectra. Elemental compositions for Mg, Al, S, Ca, Ti, and Fe have been derived from these measurements and are in line, to within expected uncertainties, with those inferred from solar-induced XRF. This agreement confirms the value of electron-induced X-ray emission measurements as a tool for geochemical analysis at Mercury.

  6. X-ray Fluorescence Measurements with the Mercury Imaging X-ray Spectrometer

    NASA Astrophysics Data System (ADS)

    Martindale, A.; Graser, G. W.; Pearson, J. F.; MIXS Consortium

    2010-03-01

    The Mercury Imaging X-ray spectrometer (MIXS) is an instrument which will fly to Mercury on the ( joint European and Japanese) BepiColombo mission. It is designed to measure the fluorescent X-rays from he surface of the planet initiated y t he incident X -rays from the solar corona and the high energy charged particles in the solar wind. Such measurements of fluorescent i ntensities allow the determination of the elemental composition of the surface of the planet and also allow investigation of the complex coupling between the planet's magnetosphere and the solar wind. The instrument consists of a telescope (MIXS-T) which offers high surface resolution measurements during high flare states and a collimator ( MIXS-C) which offers lower spatial resolution measurements but with better sensitivity even in periods of low solar activity, when the incident flux of X-rays and charged particles is lower.

  7. Comparison of direct-total-reflection X-ray fluorescence, sweeping-total-reflection X-ray fluorescence and vapor phase decomposition-total-reflection X-ray fluorescence applied to the characterization of metallic contamination on semiconductor wafers

    Microsoft Academic Search

    Adrien Danel; Nicolas Cabuil; Thierry Lardin; Dominique Despois; Marc Veillerot; Charles Geoffroy; Motoyuki Yamagami; Hiroshi Kohno

    2008-01-01

    The issues related to the matching between the 3 modes of Total-reflection X-Ray Fluorescence available on the latest generation of commercial equipment: Direct-Total-reflection X-Ray Fluorescence, Sweeping-Total-reflection X-Ray Fluorescence and Vapor Phase Decomposition-Total-reflection X-Ray Fluorescence, are discussed for quantitative analysis of metallic contamination on Si wafers. Direct-Total-reflection X-Ray Fluorescence and Sweeping-Total-reflection X-Ray Fluorescence agrees very well (+\\/?20% for light elements, transition

  8. [Development of X-ray excited fluorescence spectrometer].

    PubMed

    Ni, Chen; Gu, Mu; Di, Wang; Cao, Dun-Hua; Liu, Xiao-Lin; Huang, Shi-Ming

    2009-08-01

    An X-ray excited fluorescence spectrometer was developed with an X-ray tube and a spectrometer. The X-ray tube, spectrometer, autocontrol method and data processing selected were roundly evaluated. The wavelength and detecting efficiency of the apparatus were calibrated with the mercury and tungsten bromine standard lamps, and the X-ray excited emission spectra of BaF2, Cs I (Tl) crystals were measured. The results indicate that the apparatus has advantages of good wavelength resolution, high stability, easy to operation and good radioprotection. It is a wery effective tool for exploration of new scintillation materials. PMID:19839360

  9. Comparison of a portable micro-X-ray fluorescence spectrometry with inductively coupled plasma atomic emission spectrometry for the ancient ceramics analysis

    NASA Astrophysics Data System (ADS)

    Papadopoulou, D. N.; Zachariadis, G. A.; Anthemidis, A. N.; Tsirliganis, N. C.; Stratis, J. A.

    2004-12-01

    Two multielement instrumental methods of analysis, micro X-ray fluorescence spectrometry (micro-XRF) and inductively coupled plasma atomic emission spectrometry (ICP-AES) were applied for the analysis of 7th and 5th century B.C. ancient ceramic sherds in order to evaluate the above two methods and to assess the potential to use the current compact and portable micro-XRF instrument for the in situ analysis of ancient ceramics. The distinguishing factor of interest is that micro-XRF spectrometry offers the possibility of a nondestructive analysis, an aspect of primary importance in the compositional analysis of cultural objects. Micro-XRF measurements were performed firstly directly on the ceramic sherds with no special pretreatment apart from surface cleaning (micro-XRF on sherds) and secondly on pressed pellet disks which were prepared for each ceramic sherd (micro-XRF on pellet). For the ICP-AES determination of elements, test solutions were prepared by the application of a microwave-assisted decomposition procedure in closed high-pressure PFA vessels. Also, the standard reference material SARM 69 was used for the efficiency calibration of the micro-XRF instrument and was analysed by both methods. In order to verify the calibration, the standard reference materials NCS DC 73332 and SRM620 as well as the reference materials AWI-1 and PRI-1 were analysed by micro-XRF. Elemental concentrations determined by the three analytical procedures (ICP-AES, micro-XRF on sherds and micro-XRF on pellets) were statistically treated by correlation analysis and Student's t-test (at the 95% confidence level).

  10. X-ray fluorescence imaging with synchrotron radiation

    SciTech Connect

    Rivers, M.L.

    1987-01-01

    The micro-distribution of trace elements is of great interest in fields such as geochemistry, biology and material science. The synchrotron x-ray fluorescence microprobe provides a technique to quantitatively measure trace element compositions at individual points and to construct semiquantitative two dimensional maps of trace element compositions. This paper describes an x-ray fluorescence system used at the National Synchrotron Light Source.

  11. X-ray fluorescence and X-ray transmission microtomography imaging system

    NASA Astrophysics Data System (ADS)

    Pereira, Gabriela R.; Rocha, Henrique S.; Anjos, Marcelino J.; Faria, Paulo; Pérez, Carlos A.; Lopes, Ricardo T.

    2007-10-01

    An X-ray Transmission Microtomography (CT) system combined with an X-ray Fluorescence Microtomography (XRFCT) system was implemented in the Brazilian Synchrotron Light Source (LNLS), Campinas, Brazil. The main aim of this work is to determine the elemental and absorption distribution map in breast tissue samples. The experiments were performed at the X-Ray Fluorescence beamline (D09B-XRF) of the Brazilian Synchrotron Light Source (LNLS), Campinas, Brazil. A quasi-monochromatic beam produced by a multilayer monochromator was used as an incident beam. The fluorescence photons were acquired with an energy dispersive HPGe detector (CANBERRA Industries Inc.) placed at 90? to the incident beam, while transmitted photons were detected with a fast Na(Tl) scintillation counter (CYBERSTAR Oxford Danfysik) placed behind the sample in the beam direction. All the tomographic images were reconstructed using a filtered-back projection algorithm.

  12. A method of generating k-fluorescence x-rays

    SciTech Connect

    Fox, R.A.; Hooker, C.D.; McDonald, J.C.

    1992-04-01

    For radiation protection purposes of k-fluorescence x-rays are useful for determining the energy response of instruments and dosimeters because they are nearly monoenergetic. the International Organization for Standardization (ISO) has specified the x-ray energies and radiator and filter materials for the production of such x-rays. There are two techniques useful for producing x-rays at approximately 17 and 59 keV; these techniques produce a situation that approximates the x-ray and gamma ray emissions of plutonium and americium isotopes. The Department of Energy Laboratory Accreditation Program (DOELAP) performance-testing standard for personnel dosimeters incorporates these k-fluorescence techniques. The Radiation Calibrations Facility at the Pacific Northwest Laboratory (PNL) has produced k-fluorescence x-rays for many years. Over the years, we have worked at improving this type of radiation for our performance-testing programs. This report describes the present geometry for the generation of k-fluorescence x-rays, a geometry proven more efficient in our facility. The exposure rate has increased and the beam uniformity has improved. Details of the geometry will be discussed.

  13. Diffraction and holography of photoelectrons and fluorescent x-rays

    SciTech Connect

    Fadley, C.S. [Lawrence Berkeley Lab., CA (United States)]|[California Univ., Davis, CA (United States). Dept. of Physics

    1993-04-01

    Photoelectron diffraction is by now a powerful technique for studying surface structures, with special capabilities for resolving chemical and magnetic states of atoms and deriving direct structural information from both forward scattering and backscattering. Fitting experiment to theory can lead to structural accuracies in the 0.03 {Angstrom} range. Holographic inversions of such diffraction data also show considerable promise for deriving local three-dimensional structures around a given emitter with accuracies of 0.2--0.3 {Angstrom}. Resolving the photoelectron spin in some way and using circularly polarized radiation for excitation provide added dimensions for the study of magnetic systems and chiral experimental geometries. Synchrotron radiation with the highest brightness and energy resolution, as well as variable polarization, is crucial to the full exploitation of these techniques. X-ray fluorescence holography also has promise for structural studies, but will require intense excitation sources and multichannel detection to be feasible.

  14. An X-ray fluorescence spectrometer and its applications in materials studies

    NASA Technical Reports Server (NTRS)

    Singh, J. J.; Han, K. S.

    1977-01-01

    An X-ray fluorescence system based on a Co(57) gamma-ray source has been developed. The system was used to calculate the atomic percentages of iron implanted in titanium targets. Measured intensities of Fe (k-alpha + k-beta) and Ti (k-alpha + k-beta) X-rays from the Fe-Ti targets are in good agreement with the calculated values based on photoelectric cross sections of Ti and Fe for the Co(57) gamma rays.

  15. High-resolution hard-X-ray fluorescence spectrometer

    NASA Astrophysics Data System (ADS)

    Kleimenov, Evgueni; Bergamaschi, Anna; van Bokhoven, Jeroen; Janousch, Markus; Schmitt, Bernd; Nachtegaal, Maarten

    2009-11-01

    A Johann-type X-ray fluorescence spectrometer for XES, RXES/RIXS, HERFD XAS and RXS experiments was designed, constructed and commissioned at the X10DA-SuperXAS beamline of the Swiss Light Source. The spectrometer consists of three key elements: a sample manipulator, an X-ray dispersive element (spherically bent silicon or germanium crystal), and an one-dimensional-array X-ray detector. The detected X-ray fluorescence energy is scanned by changing the angle between the sample, crystal and detector. The energy resolution of the spectrometer ranges from sub-eV to several eV. Thanks to the use of a one-dimensional array detector the spectrometer is easy to align and operate.

  16. Characterization of LCLS X-Ray Pulses Using Atomic Spectroscopy

    Microsoft Academic Search

    A. M. March; L. Young; S. H. Southworth; E. P. Kanter; B. Krässig; R. Santra; Y. Li; S. T. Pratt; N. Berrah; M. Höner; L. Fang; J. P. Cryan; J. M. Glownia; D. A. Reis; S. Ghimire; P. Bucksbaum; L. Dimauro; G. Doumy; C. Roedig; J. D. Bozek; C. Bostedt; M. Messerschmidt

    2010-01-01

    The first experiments at the LCLS succeeded in not only revealing the nature of interactions between intense x-rays and atomic or molecular systems, but also properties of the LCLS x-ray pulses. Our spectroscopic measurements of the interaction with neon atoms have revealed information on x-ray photon energy, the pulse duration, and the focal spot size. When analyzed in conjunction with

  17. Development and application of glancing incident X-ray fluorescence spectrometry using parallel polycapillary X-ray lens

    Microsoft Academic Search

    Jun Yang; Dandan Zhao; Qing Xu; Xunliang Ding

    2009-01-01

    A new glancing incident X-ray fluorescence (GIXRF) spectrometer using parallel polycapillary X-ray lens has been developed. Integrated with a Zr filter and slits, a highly collimated and monochromatic X-ray beam has been achieved. This method eliminated the monochromator used in the conventional GIXRF method. Moreover the parallel X-ray lens increased the acceptance solid angle and hence increases intensities of the

  18. 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.

  19. Development of a coincidence system for the measurement of X-ray emission atomic parameters

    SciTech Connect

    Martinez, Filiberto; Miranda, Javier [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364, 01000 Mexico, D.F (Mexico)

    2013-07-03

    Preliminary results obtained in experiments carried out with an x-ray spectrometer built at the Instituto de Fisica for Atomic Physics and environmental sciences studies are presented. The experiments are based on a coincidence method for signals produced by LEGe and Si(Li) detectors. The x-ray fluorescence yields ({omega}{sub Li}) and Coster-Kronig transition probabilities (f{sub ij}) for elements with 55 {<=} Z {<=} 60 are among the quantities of interest. The method is based on the simultaneous detection of K x-rays with the LEGe detector and the L x-rays with the Si(Li) detector. The primary radiation source is an x-ray tube with Rh anode. The system was tested with the coincidence of the L x-rays from Ce with its K line, demonstrating the feasibility of the experiments.

  20. X-ray fluorescence analysis of various alloys. Part 1

    SciTech Connect

    Charles, J.W. Jr.; Ferguson, M.R.; Eager, M.H.

    1980-02-15

    For a number of years, x-ray fluorescence spectrometry has been used in the Y-12 Plant Laboratory for the analysis of a wide variety of materials. During the past few years, the technique has been applied to the analysis of a large number of experimental alloys. The general procedure consists of the following steps: (1) ignition of the alloy to oxides, (2) addition of suitable internal standards, (3) dissolution of the oxides and internal standards by sodium tetraborate (borax) fusion, (4) casting a pellet from the fusion in a graphite mold (Figure 1), and (5) determination of the major constituents by x-ray fluorescence spectrometry.

  1. Progress in biomedical application of phase-contrast x-ray imaging and fluorescent x-ray CT

    Microsoft Academic Search

    Tohoru Takeda; Jin Wu; Thet-Thet Lwin; Akio Yoneyama; Yasuharu Hirai; Kazuyuki Hyodo; Naoki Sunaguchi; Tetsuya Yuasa; Manabu Minami; Katsumi Kose; Takao Akatsuka

    2006-01-01

    X-ray CT system with phase-contrast and fluorescent techniques are being developed for biomedical researches. We have applied these techniques for in-vivo and ex-vivo imaging. The phase-contrast x-ray CT enables to reveal the detailed morphological information of cancer lesion, and image quality of ex-vivo specimen was excellent comparing to 4.74T micro-MRI. Fluorescent x-ray CT could depict the functional information with high

  2. Instrument and method for X-ray diffraction, fluorescence, and crystal texture analysis without sample preparation

    NASA Technical Reports Server (NTRS)

    Gendreau, Keith (Inventor); Martins, Jose Vanderlei (Inventor); Arzoumanian, Zaven (Inventor)

    2010-01-01

    An X-ray diffraction and X-ray fluorescence instrument for analyzing samples having no sample preparation includes a X-ray source configured to output a collimated X-ray beam comprising a continuum spectrum of X-rays to a predetermined coordinate and a photon-counting X-ray imaging spectrometer disposed to receive X-rays output from an unprepared sample disposed at the predetermined coordinate upon exposure of the unprepared sample to the collimated X-ray beam. The X-ray source and the photon-counting X-ray imaging spectrometer are arranged in a reflection geometry relative to the predetermined coordinate.

  3. Archaeometrical studies using X-ray fluorescence methods

    SciTech Connect

    Pauna, Catalina; Constantinescu, B.; Constantin, F.; Bugoi, R.; Stan, D.; Vasilescu, A. [National Institute of Nuclear Physics and Engineering, POB MG-6, 077125, Bucharest (Romania)

    2010-04-26

    Elemental analysis contributes to authentication (knowing the elemental composition and considering the information about the usual composition of the objects in different historical periods it can be established if the item is original or fake), provenance studies (minor and trace elements indicates ores origin and 'consequently' mines location), (relative) dating of archaeological objects (e.g. for painted items--the chemical recipes for pigments can offer information about the age of objects). The paper gives a general layout for the NIPNE Archaeometry Laboratory's applications using X-Ray Fluorescence (XRF), micro--Proton Induced X-Ray Emission (micro-PIXE), micro-Synchrotron Radiation Induced X-Ray Fluorescence (micro--SR-XRF) methods.

  4. Archaeometrical studies using X-ray fluorescence methods

    NASA Astrophysics Data System (ADS)

    Pauna, Catalina; Constantinescu, B.; Constantin, F.; Bugoi, R.; Stan, D.; Vasilescu, A.

    2010-04-01

    Elemental analysis contributes to authentication (knowing the elemental composition and considering the information about the usual composition of the objects in different historical periods it can be established if the item is original or fake), provenance studies (minor and trace elements indicates ores origin and "consequently" mines location), (relative) dating of archaeological objects (e.g. for painted items—the chemical recipes for pigments can offer information about the age of objects). The paper gives a general layout for the NIPNE Archaeometry Laboratory's applications using X-Ray Fluorescence (XRF), micro—Proton Induced X-Ray Emission (micro-PIXE), micro-Synchrotron Radiation Induced X-Ray Fluorescence (micro—SR-XRF) methods.

  5. L-shell x-ray fluorescence measurements of lead in bone: accuracy and precision

    Microsoft Academic Search

    Andrew C. Todd; Spencer Carroll; Ciaran Geraghty; Fuad A. Khan; Erin L. Moshier; Shida Tang; Patrick J. Parsons

    2002-01-01

    This study aimed to quantify the accuracy and precision of a method for in vivo measurements of lead in bone using L-shell x-ray fluorescence (LXRF), the former via comparison with independent measurements of lead in bone obtained using electrothermal atomic absorption spectrometry (AAS) following acid digestion. Using LXRF, the lead content of adult human cadaver tibiae was measured, both as

  6. 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.

  7. Apollo 15 Geochemical X-ray Fluorescence Experiment: Preliminary Report

    Microsoft Academic Search

    I. Adler; J. Trombka; J. Gerard; P. Lowman; R. Schmadebeck; H. Blodget; E. Eller; L. Yin; R. Lamothe; P. Gorenstein; P. Bjorkholm

    1972-01-01

    Although only part of the information from the x-ray fluorescence geochemical experiment has been analyzed, it is clear that the experiment was highly successful. Significant compositional differences among and possibly within the maria and highlands have been detected. When viewed in the light of analyzed lunar rocks and soil samples, and the data from other lunar orbital experiments (in particular,

  8. Computer simulation of a backscattered X-ray fluorescence system.

    PubMed

    Al-Ghorabie, Fayez H H

    2015-01-01

    An EGSnrc user code is developed to simulate a backscattered geometry in vivo x-ray fluorescence system for the measurement of platinum concentration in head and neck tumours. The user code is fundamentally based on a previous study which used the EGS4 Monte Carlo code. The new user code, which we have developed in this study, has new improvements which made it able to simulate the process of photon transportation through the different components of the modelled x-ray fluorescence system. The simulation process included modelling of the photon source, collimators, phantoms and detector. Simulation results were compared and evaluated against x-ray fluorescence data obtained experimentally from an existing system developed by the Swansea In vivo Analysis and Cancer Research Group. In addition, simulation results of this study were also compared with our previous study in which the EGS4 user code was used. Comparison between results has shown that the new EGSnrc user code was able to reproduce the spectral shape obtained using the experimental x-ray fluorescence system. The area under the Compton peak differs by 2.5% between the experimental measurement and the EGSnrc simulation. Similarly, the area under the two Pt K? peaks differs by 2.3% and 2.2%. PMID:25567407

  9. Measuring and interpreting X-ray fluorescence from planetary surfaces.

    PubMed

    Owens, Alan; Beckhoff, Burkhard; Fraser, George; Kolbe, Michael; Krumrey, Michael; Mantero, Alfonso; Mantler, Michael; Peacock, Anthony; Pia, Maria-Grazia; Pullan, Derek; Schneider, Uwe G; Ulm, Gerhard

    2008-11-15

    As part of a comprehensive study of X-ray emission from planetary surfaces and in particular the planet Mercury, we have measured fluorescent radiation from a number of planetary analog rock samples using monochromatized synchrotron radiation provided by the BESSY II electron storage ring. The experiments were carried out using a purpose built X-ray fluorescence (XRF) spectrometer chamber developed by the Physikalisch-Technische Bundesanstalt, Germany's national metrology institute. The XRF instrumentation is absolutely calibrated and allows for reference-free quantitation of rock sample composition, taking into account secondary photon- and electron-induced enhancement effects. The fluorescence data, in turn, have been used to validate a planetary fluorescence simulation tool based on the GEANT4 transport code. This simulation can be used as a mission analysis tool to predict the time-dependent orbital XRF spectral distributions from planetary surfaces throughout the mapping phase. PMID:18855420

  10. New spectrometer for grazing exit x-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Pérez, Roberto D.; Sánchez, Héctor Jorge

    1997-07-01

    Among the x-ray fluorescence techniques using energy dispersive systems, the excitation in the total reflection regime is becoming widespread. This technique may be applied to surface analysis if the fluorescent radiation emitted by the sample is measured as a function of the grazing incidence angle. The main limitation in performing this sort of analysis is the need to use a monochromator, which notably reduces the incident flux of radiation. Besides, the method requires the radiated surface to be perfectly smooth and polished and to have a total length of some centimeters. A similar technique known as grazing exit x-ray fluorescence presents certain advantages and is easier to implement. By this method, fluorescent photons in terms of the grazing exit angle are detected. In this work, a spectrometer for performing surface analysis at grazing exit is described, the different experimental situations are analyzed, and some measurements performed with this device are shown.

  11. Basic studies on x-ray fluorescence analysis for active x-ray spectrometer on SELENE-2

    NASA Astrophysics Data System (ADS)

    Kusano, Hiroki; Hasebe, Nobuyuki; Nagaoka, Hiroshi; Kodama, Takuro; Oyama, Yuki; Tanaka, Reiko; Amano, Yoshiharu; Kim, Kyeong J.; Matias Lopes, Josè A.

    2013-09-01

    An active X-ray spectrometer (AXS) is now being developed as a payload candidate for the rover on SELENE-2, the next Japanese lunar exploration mission. The AXS will determine the chemical compositions of lunar rocks and regolith around the landing site. The surface of lunar rock samples will be ground using a rock abrasion tool. Thus, fundamental studies on the X-ray fluorescence analysis for lunar rocks and regolith are required to design and develop the AXS. In this study, we have investigated the X-ray fluorescence analysis in order to evaluate the effects of surface roughness of samples and the angle of incident and emergent X-rays. It was found that the fluorescent X-ray yield for low energy X-rays, i.e. the light elements, decreases at rough surface samples. This effect of surface roughness becomes small for smooth surface samples. It was also found that the fluorescent X-ray yield depends on the incident angle, which is attributed to the fact that the X-ray fluorescence occurs closer to the sample surface at larger incident angles. Since the emergent X-rays are affected by the detection geometry and surface roughness, the incident angle effect also depends on the above conditions.

  12. Trace characterization of high-purity molybdenum and tungsten by electrothermal atomic absorption spectrometry, inductively coupled plasma atomic emission spectrometry, inductively coupled plasma mass spectrometry and total reflection X-ray fluorescence spectrometry involving analyte—matrix separation

    NASA Astrophysics Data System (ADS)

    Krivan, Viliam; Theimer, Karl-Heinz

    1997-12-01

    A technique for the separation of 42 trace elements from up to 5 g of molybdenum and tungsten matrices was developed by means of the radiotracer technique. It is based on adsorption of the analyses on the cation exchanger Dowex 50 W x 9 from a 4% H 2O 2/0.01 mol 1 -1 HNO 3 solution followed by their elution with 15 ml of 4 mol I -1 HNO 3 in the opposite flow direction. Both matrices were removed with a separation factor > 10 4. The separation technique was applied to the analysis of these materials by electrothermal atomic absorption spectrometry, inductively coupled plasma atomic emission spectrometry, inductively coupled plasma mass spectrometry and total reflection X-ray fluorescence spetrometry. For all the determination methods used, the limits of detection are given and compared with those of other methods. With inductively coupled plasma mass spectrometry, for 22 of the 30 assayed elements, limits of detection at the sub-ng g -1 level were achieved. The results are compared with those obtained by radiochemical neutron activation analysis in this work and by glow discharge mass spectrometry, secondary ion mass spectrometry, isotope dilution mass spectrometry and by solution spectrometric methods in other laboratories.

  13. HIgh Rate X-ray Fluorescence Detector

    SciTech Connect

    Grudberg, Peter Matthew [XIA LLC

    2013-04-30

    The purpose of this project was to develop a compact, modular multi-channel x-ray detector with integrated electronics. This detector, based upon emerging silicon drift detector (SDD) technology, will be capable of high data rate operation superior to the current state of the art offered by high purity germanium (HPGe) detectors, without the need for liquid nitrogen. In addition, by integrating the processing electronics inside the detector housing, the detector performance will be much less affected by the typically noisy electrical environment of a synchrotron hutch, and will also be much more compact than current systems, which can include a detector involving a large LN2 dewar and multiple racks of electronics. The combined detector/processor system is designed to match or exceed the performance and features of currently available detector systems, at a lower cost and with more ease of use due to the small size of the detector. In addition, the detector system is designed to be modular, so a small system might just have one detector module, while a larger system can have many â?? you can start with one detector module, and add more as needs grow and budget allows. The modular nature also serves to simplify repair. In large part, we were successful in achieving our goals. We did develop a very high performance, large area multi-channel SDD detector, packaged with all associated electronics, which is easy to use and requires minimal external support (a simple power supply module and a closed-loop water cooling system). However, we did fall short of some of our stated goals. We had intended to base the detector on modular, large-area detectors from Ketek GmbH in Munich, Germany; however, these were not available in a suitable time frame for this project, so we worked instead with pnDetector GmbH (also located in Munich). They were able to provide a front-end detector module with six 100 m^2 SDD detectors (two monolithic arrays of three elements each) along with associated preamplifiers; these detectors surpassed the performance we expected to get from the Ketek detectors, however they are housed in a sealed module, which does not offer the ease of repair and expandability weâ??d hoped to achieve with the Ketek SDDâ??s. Our packaging efforts were quite successful, as we came up with a very compact way to mount the detector and to house the associated electronics, as well as a very effective way to reliably take out the heat (from the electronics as well as the detectorâ??s Peltier coolers) without risk of condensation and without external airflow or vibration, which could create problems for the target applications. While we were able to design compact processing electronics that fit into the detector assembly, they are still at the prototype stage, and would require a significant redesign to achieve product status. We have not yet tested this detector at a synchrotron facility; we do still plan on working with some close contacts at the nearby Stanford Synchrotron Radiation Laboratory (SSRL) to get some testing with the beam (using existing commercial electronics for readout, as the integrated processor is not ready for use).

  14. Calculating the X-Ray Fluorescence from the Planet Mercury Due to High-Energy Electrons

    NASA Technical Reports Server (NTRS)

    Burbine, T. H.; Trombka, J. I.; Bergstrom, P. M., Jr.; Christon, S. P.

    2005-01-01

    The least-studied terrestrial planet is Mercury due to its proximity to the Sun, which makes telescopic observations and spacecraft encounters difficult. Our lack of knowledge about Mercury should change in the near future due to the recent launching of MESSENGER, a Mercury orbiter. Another mission (BepiColombo) is currently being planned. The x-ray spectrometer on MESSENGER (and planned for BepiColombo) can characterize the elemental composition of a planetary surface by measuring emitted fluorescent x-rays. If electrons are ejected from an atom s inner shell by interaction with energetic particles such as photons, electrons, or ions, electrons from an outer shell can transfer to the inner shell. Characteristic x-rays are then emitted with energies that are the difference between the binding energy of the ion in its excited state and that of the ion in its ground state. Because each element has a unique set of energy levels, each element emits x-rays at a unique set of energies. Electrons and ions usually do not have the needed flux at high energies to cause significant x-ray fluorescence on most planetary bodies. This is not the case for Mercury where high-energy particles were detected during the Mariner 10 flybys. Mercury has an intrinsic magnetic field that deflects the solar wind, resulting in a bow shock in the solar wind and a magnetospheric cavity. Electrons and ions accelerated in the magnetosphere tend to follow its magnetic field lines and can impact the surface on Mercury s dark side Modeling has been done to determine if x-ray fluorescence resulting from the impact of high-energy electrons accelerated in Mercury's magnetosphere can be detected by MESSENGER. Our goal is to understand how much bulk chemical information can be obtained from x-ray fluorescence measurements on the dark side of Mercury.

  15. Portable energy dispersive X-ray fluorescence and X-ray diffraction and radiography system for archaeometry

    NASA Astrophysics Data System (ADS)

    Mendoza Cuevas, Ariadna; Perez Gravie, Homero

    2011-03-01

    Starting on a laboratory developed portable X-ray fluorescence (PXRF) spectrometer; three different analytical results can be performed: analysis of chemical elements, analysis of major chemical crystalline phase and structural analysis, which represents a contribution to a new, low cost development of portable X-ray analyzer; since these results are respectively obtained with independent equipments for X-ray fluorescence, X-ray diffraction and radiography. Detection limits of PXRF were characterized using standard reference materials for ceramics, glass, bronze and bones, which are the main materials requiring quantitative analysis in art and archeological objects. A setup for simultaneous energy dispersive X-ray fluorescence and diffraction (ED (XRF-XRD)) in the reflection mode has been tested for in situ and non-destructive analysis according to the requirements of art objects inspection. The system uses a single low power X-ray tube and an X-ray energy dispersive detector to measure X-ray diffraction spectrum at a fixed angle. Application to the identification of jadeite-jade mineral in archeological objects by XRD is presented. A local high resolution radiography image obtained with the same low power X-ray tube allows for studies in painting and archeological bones.

  16. Proton-induced x-ray fluorescence CT imaging

    PubMed Central

    Bazalova-Carter, Magdalena; Ahmad, Moiz; Matsuura, Taeko; Takao, Seishin; Matsuo, Yuto; Fahrig, Rebecca; Shirato, Hiroki; Umegaki, Kikuo; Xing, Lei

    2015-01-01

    Purpose: To demonstrate the feasibility of proton-induced x-ray fluorescence CT (pXFCT) imaging of gold in a small animal sized object by means of experiments and Monte Carlo (MC) simulations. Methods: First, proton-induced gold x-ray fluorescence (pXRF) was measured as a function of gold concentration. Vials of 2.2 cm in diameter filled with 0%–5% Au solutions were irradiated with a 220 MeV proton beam and x-ray fluorescence induced by the interaction of protons, and Au was detected with a 3 × 3 mm2 CdTe detector placed at 90° with respect to the incident proton beam at a distance of 45 cm from the vials. Second, a 7-cm diameter water phantom containing three 2.2-diameter vials with 3%–5% Au solutions was imaged with a 7-mm FWHM 220 MeV proton beam in a first generation CT scanning geometry. X-rays scattered perpendicular to the incident proton beam were acquired with the CdTe detector placed at 45 cm from the phantom positioned on a translation/rotation stage. Twenty one translational steps spaced by 3 mm at each of 36 projection angles spaced by 10° were acquired, and pXFCT images of the phantom were reconstructed with filtered back projection. A simplified geometry of the experimental data acquisition setup was modeled with the MC TOPAS code, and simulation results were compared to the experimental data. Results: A linear relationship between gold pXRF and gold concentration was observed in both experimental and MC simulation data (R2 > 0.99). All Au vials were apparent in the experimental and simulated pXFCT images. Specifically, the 3% Au vial was detectable in the experimental [contrast-to-noise ratio (CNR) = 5.8] and simulated (CNR = 11.5) pXFCT image. Due to fluorescence x-ray attenuation in the higher concentration vials, the 4% and 5% Au contrast were underestimated by 10% and 15%, respectively, in both the experimental and simulated pXFCT images. Conclusions: Proton-induced x-ray fluorescence CT imaging of 3%–5% gold solutions in a small animal sized water phantom has been demonstrated for the first time by means of experiments and MC simulations. PMID:25652502

  17. High spatial resolution in x-ray fluorescence

    SciTech Connect

    Zahrt, J.D.

    1986-01-01

    The design of diffracting crystals for use in x-ray fluorescence spectrometers is discussed. Characteristics of the Johan and Johansson geometries are discussed and intensity profiles are developed. If the diffraction line has a finite width, concentration gradients will not be faithfully reproduced by gradients in the signal as the sample is scanned. Boundary effects for four types of concentration gradient are presented; as step function, linear gradients, exponential gradient, and Gaussian gradient. (DWL) 13 refs., 8 figs.

  18. High resolution x-ray fluorescence spectroscopy - a new technique for site- and spin-selectivity

    SciTech Connect

    Wang, Xin [Univ. of California, Davis, CA (United States). Dept. of Applied Science

    1996-12-01

    X-ray spectroscopy has long been used to elucidate electronic and structural information of molecules. One of the weaknesses of x-ray absorption is its sensitivity to all of the atoms of a particular element in a sample. Through out this thesis, a new technique for enhancing the site- and spin-selectivity of the x-ray absorption has been developed. By high resolution fluorescence detection, the chemical sensitivity of K emission spectra can be used to identify oxidation and spin states; it can also be used to facilitate site-selective X-ray Absorption Near Edge Structure (XANES) and site-selective Extended X-ray Absorption Fine Structure (EXAFS). The spin polarization in K fluorescence could be used to generate spin selective XANES or spin-polarized EXAFS, which provides a new measure of the spin density, or the nature of magnetic neighboring atoms. Finally, dramatic line-sharpening effects by the combination of absorption and emission processes allow observation of structure that is normally unobservable. All these unique characters can enormously simplify a complex x-ray spectrum. Applications of this novel technique have generated information from various transition-metal model compounds to metalloproteins. The absorption and emission spectra by high resolution fluorescence detection are interdependent. The ligand field multiplet model has been used for the analysis of K{alpha} and K{beta} emission spectra. First demonstration on different chemical states of Fe compounds has shown the applicability of site selectivity and spin polarization. Different interatomic distances of the same element in different chemical forms have been detected using site-selective EXAFS.

  19. X-ray fluorescence spectrometry of asteroid Itokawa by Hayabusa.

    PubMed

    Okada, Tatsuaki; Shirai, Kei; Yamamoto, Yukio; Arai, Takehiko; Ogawa, Kazunori; Hosono, Kozue; Kato, Manabu

    2006-06-01

    X-ray fluorescence spectrometry of asteroid 25143 Itokawa was performed by the x-ray spectrometer onboard Hayabusa during the first touchdown on 19 November 2005. We selected those data observed during relatively enhanced solar activity and determined average elemental mass ratios of Mg/Si = 0.78 +/- 0.09 and Al/Si = 0.07 +/- 0.03. Our preliminary results suggest that Itokawa has a composition consistent with that of ordinary chondrites, but primitive achondrites cannot be ruled out. Among ordinary chondrites, LL- or L-chondrites appear to be more likely than H-chondrites. No substantial regional difference was found on the asteroid surface, indicating its homogeneity in composition. PMID:16741109

  20. X-ray scattering and fluorescence in the wind of a massive X-ray binary

    NASA Technical Reports Server (NTRS)

    Lewis, W.; Rappaport, S.; Levine, A.; Nagase, F.

    1992-01-01

    Spectral data from the binary X-ray pulsar 4 U 0900 - 40 obtained with the Ginga satellite and covering a range of orbital phases are presented and interpreted using simulated spectra created with a Monte Carlo scattering code. It is found that scattering and fluorescence in a simple spherically symmetric distribution of matter surrounding the companion star can reproduce the eclipse spectrum, as well as the 'soft X-ray-excess' observed during egress and other orbital phases. Reasonably secure values are found for a number of the parameters that characterize the density profile of the stellar wind and atmosphere of the companion star. The Fe abundance is within a factor of about 1.3 of that in the solar neighborhood. It is shown that ionization zones are not critical to understanding the orbital-phase-resolved spectra in this source. It is also found that the contribution by scattering from interstellar dust grains to the observed spectra during eclipse is negligible, while that from diffuse emission from the 'Galactic ridge' is significant.

  1. Advances in X-ray Reflectivity (XRR) and X-ray Fluorescence (XRF) Measurements Provide Unique Advantages for Semiconductor Applications

    NASA Astrophysics Data System (ADS)

    Spear, Jennifer; Murakami, Hiroyuki; Terada, Shinichi

    2003-09-01

    We have developed a thin-film metrology tool that fulfills the metrology requirements for the production of 65nm node technology and beyond. This tool combines X-ray Reflectivity (XRR) and X-ray Fluorescence (XRF) measurements to provide accurate, high throughput, measurements. Improvements in both the XRR and XRF configurations were made to allow high throughput measurements on films as thin as 0.5 nm. The source intensity for the XRR measurements was increased using focusing X-ray optics. Wafer alignment, which is critical for XRR measurements to be accurate, is done using both X-rays and lasers to reduce the time required. A monochromatic X-ray source is used for XRF measurements since peak-to-background ratio is extremely important when detecting the XRF signal from ultra-thin films.

  2. X-ray fluorescence microtomography analyzing reference samples

    NASA Astrophysics Data System (ADS)

    Pereira, G. R.; Lopes, R. T.; Anjos, M. J.; Rocha, H. S.; Pérez, C. A.

    2007-08-01

    The X-ray fluorescence microtomography (XRFCT) is a non-destructive technique to complement other techniques used for samples characterization. The common techniques provide only information on the attenuation coefficients (transmission microtomography) or electronic density (Compton microtomography) and no information on the distribution of the elements inside of the sample can be obtained in these cases. XRFCT is based on the detection of fluorescence photons emitted by the elements in the sample. As the energy of photons of fluorescence has a particular value for each element, it is possible to obtain the distribution of all the elements in a sample, since that a minimum of fluorescence signal is detected. The experiments were performed at the X-ray fluorescence beamline (D09B-XRF) of the Brazilian Synchrotron Light Source (LNLS), Campinas, Brazil. A monochromatic beam and a white beam was used for the excitation of the elements and the fluorescence photons have been detected by a HPGe detector, placed at 90° to the incident beam. The beam was monitored by an ionization chamber and a fast scintillator detector was used to detect the transmitted radiation. In order to study the performance of the system, some reference samples made of polyethylene filled with standard solutions were analyzed, and some tissues of human breast (normal tissue, benign tumor and malignant tumor) have been analyzed in order to verify the efficiency of the system in determination of the elemental distribution in these kinds of samples. All the tomographic images were reconstructed using a filtered-back projection algorithm. In the breast tissue samples, the elements of higher concentration were Zn, Cu and Fe.

  3. Atomic Data Needs for X-Ray Astronomy

    NASA Technical Reports Server (NTRS)

    Kallman, Timothy; White, Nicholas E. (Technical Monitor)

    1999-01-01

    This publication contains written versions of most of the invited talks presented at the workshop on Atomic Data Needs for X-ray Astronomy which was held at NASA's Goddard Space Flight Center on December 16-1 7 1999. The idea of hosting such a workshop emerged from an imminent need to update and complete current atomic datasets in anticipation of a new era of high quality X-ray spectra starting with the launching of Chandra and XMM-Newton observatories. At first, our vision of the workshop was of a short and limited attendance event, given the specialization of the topic. But it, was soon realized, from the response to the first workshop announcement, that the topic was of much interest, to researchers working in X-ray spectra (physicists and astronomers). As a result, the workshop grew to approximately 120 participants from several countries. The kind of atomic data that interests us are those parameters needed for analysis and modeling of spectra shortward of about about 100 A and relevant to ionic species of astronomical interest. The physical mechanisms of interest in the formation of spectra include photoionization. collisional ionization, recombination (radiative and dielectronic). collisional excitation (by electrons and protons). and radiative deexcitation. Unique to X-ray spectroscopy are the ionization and excitation processes from inner-closed shells. in addition to the challenges in interpret,ing the medium resolution (epsilon/delta epsilon is about 0.05 - 0.1) data obtained by current X-ray astronomy experiments. Line wavelengths are of interest too, particularly owing to the high resolution spectra from the new experiments. The workshop was divided into five major areas: Observational Spectroscopy, Theoretical Calculations of Atomic Data, Laboratory Measurements of Atomic Parameters. Spectra Modeling, and Atomic Databases. One comforting finding from the work shop is that the enthusiasm felt by X-ray astronomers about the new observational missions seems to be shared by theoretical and experimental physicists. Talks were presented about several exciting new projects and experimental and theoretical techniques devoted to X-ray spectroscopy. Simultaneously, several new tools for spectral analysis and modeling have recently been developed, together with improved atomic databases. These proceeding are expected to be of interests to producers and users of atomic data. Moreover. the contributions presented here have been written in a way that can be used by a general audience of scientists and graduate students in X-ray astronomy, modelling, and in computational and experimental atomic physics.

  4. Advances in X-ray Reflectivity (XRR) and X-ray Fluorescence (XRF) Measurements Provide Unique Advantages for Semiconductor Applications

    Microsoft Academic Search

    Jennifer Spear; Hiroyuki Murakami; Shinichi Terada

    2003-01-01

    We have developed a thin-film metrology tool that fulfills the metrology requirements for the production of 65nm node technology and beyond. This tool combines X-ray Reflectivity (XRR) and X-ray Fluorescence (XRF) measurements to provide accurate, high throughput, measurements. Improvements in both the XRR and XRF configurations were made to allow high throughput measurements on films as thin as 0.5 nm.

  5. Milli X-ray fluorescence X-ray spectrum imaging for measuring potassium ion intrusion into concrete samples

    Microsoft Academic Search

    Jeffrey M. Davis; Dale E. Newbury; Prasada rao Rangaraju; Senthil Soundrapanian; Colin Giebson

    2009-01-01

    Of particular interest when studying the effects of deicing solutions on concrete is the depth of penetration of ions from deicing salts. To determine the limits of positive ion infiltration, a method based on milli X-ray fluorescence (mXRF) has been developed. This method combines traditional energy dispersive spectrometry (EDS) with stage movement X-ray mapping to analyze comparatively large areas of

  6. Atomic Data Needs for X-ray Astronomy

    NASA Technical Reports Server (NTRS)

    Bautista, Manuel A. (Editor); Kallman, Timothy R. (Editor); Pradhan, Anil K. (Editor)

    2000-01-01

    This publication contains written versions of most of the invited talks presented at the workshop on "Atomic Data Needs for X-ray Astronomy," which was held at NASA's Goddard Space Flight Center on December 16-17, 1999. The workshop was divided into five major areas: Observational Spectroscopy, Theoretical Calculations of Atomic Data, Laboratory Measurements of Atomic Parameters, Spectra Modeling, and Atomic Databases. These proceedings are expected to be of interest to producers and users of atomic data. Moreover, the contributions presented here have been written in a way that can be used by a general audience of scientists and graduate students in X-ray astronomy, modelling, and in computational and experimental atomic physics.

  7. X-ray spectroscopy of kaonic atoms at SIDDHARTA

    NASA Astrophysics Data System (ADS)

    Cargnelli, M.; Bazzi, M.; Beer, G.; Berucci, C.; Bragadireanu, A. M.; Curceanu, C.; d'Uffizi, A.; Fiorini, C.; Ghio, F.; Guaraldo, C.; Hayano, R.; Iliescu, M.; Ishiwatari, T.; Iwasaki, M.; Levi Sandri, P.; Marton, J.; Okada, S.; Pietreanu, D.; Ponta, T.; Quaglia, R.; Romero Vidal, A.; Sbardella, E.; Scordo, A.; Shi, H.; Sirghi, D. L.; Sirghi, F.; Tatsuno, H.; Vazquez Doce, O.; Widmann, E.; Wünschek, B.; Zmeskal, J.

    2014-06-01

    The X-ray measurements of kaonic atoms play an important role for understanding the low-energy QCD in the strangeness sector. The SIDDHARTA experiment studied the X-ray transitions of 4 light kaonic atoms (H, D, 3He, and 4He) using the DAFNE electron-positron collider at LNF (Italy). Most precise values of the shift and width of the kaonic hydrogen 1s state were determined, which have been now used as fundamental information for the low-energy K-p interaction in theoretical studies. An upper limit of the X-ray yield of kaonic deuterium was derived, important for future K-d experiments. The shifts and widths of the kaonic 3He and 4He 2p states were obtained, confirming the end of the "kaonic helium puzzle". In this contribution also the plans for new experiments of kaonic deuterium are being presented.

  8. Atomic Multiplets in X-ray Spectroscopies of Solids

    NASA Astrophysics Data System (ADS)

    Delley, Bernard; Uldry, Anne-Christine

    2013-03-01

    The electronic structures of compounds involving open d- and f- shell are studied frequently by X-ray and electron spectroscopies. For a better understanding of the multiplets arising in spectra involving one or more open shells, we have developed recently an easy to use program multiX,[2] which is available to download.[3] This first step allows the inclusion of the crystal environment as a crystal field entered simply as positions and charges of a cluster of atoms around the core hole site. This often gives valuable insights in the case of x-ray absorption spectroscopy (XAS) and resonant inelastic x-ray spectroscopy (RIXS) measurements. However, in many cases it is desirable to allow for hybridization of the open shell electrons with the orbitals of neighbor atoms. This requires dealing with a significantly larger active Hilbert space. This is addressed with our recent Lanczos-based procedure to calculate spectra. First results will be discussed. The electronic structures of compounds involving open d- and f- shell are studied frequently by X-ray and electron spectroscopies. For a better understanding of the multiplets arising in spectra involving one or more open shells, we have developed recently an easy to use program multiX,[2] which is available to download.[3] This first step allows the inclusion of the crystal environment as a crystal field entered simply as positions and charges of a cluster of atoms around the core hole site. This often gives valuable insights in the case of x-ray absorption spectroscopy (XAS) and resonant inelastic x-ray spectroscopy (RIXS) measurements. However, in many cases it is desirable to allow for hybridization of the open shell electrons with the orbitals of neighbor atoms. This requires dealing with a significantly larger active Hilbert space. This is addressed with our recent Lanczos-based procedure to calculate spectra. First results will be discussed. Swiss SNF grant 200021-129970 is gratefully acknowledged.

  9. X-ray scattering in X-ray fluorescence spectra with X-ray monochromatic, polarised excitation - Modelling, experiment, and Monte-Carlo simulation

    NASA Astrophysics Data System (ADS)

    Hodoroaba, V.-D.; Radtke, M.; Reinholz, U.; Riesemeier, H.; Vincze, L.; Reuter, D.

    2011-07-01

    A systematic series of measurements has been carried out with monochromatic X-ray excitation with synchrotron radiation in order to check a physical model on X-ray scattering. The model has recently been successfully tested for the case of polychromatic, unpolarised excitation emitted by an X-ray tube. Our main purpose is the modelling of a physical background in X-ray fluorescence spectra, so that improved quantitative results can be achieved especially for strongly scattering specimens. The model includes single Rayleigh and Compton scattering in the specimen, the effect of bound electrons, the challenging Compton broadening and the polarisation degree. Representative specimens, measurement geometries and excitation energies have been selected with synchrotron monochromatic light at BAM line/BESSY II. Monte-Carlo simulations have been also carried out in order to evaluate the quality of the results achieved with the model.

  10. Comparison of the data of X-ray microtomography and fluorescence analysis in the study of bone-tissue structure

    NASA Astrophysics Data System (ADS)

    Asadchikov, V. E.; Senin, R. A.; Blagov, A. E.; Buzmakov, A. V.; Gulimova, V. I.; Zolotov, D. A.; Orekhov, A. S.; Osadchaya, A. S.; Podurets, K. M.; Savel'ev, S. V.; Seregin, A. Yu.; Tereshchenko, E. Yu.; Chukalina, M. V.; Kovalchuk, M. V.

    2012-09-01

    The possibility of localizing clusters of heavy atoms is substantiated by comparing the data of X-ray microtomography at different wavelengths, scanning electron microscopy, and X-ray fluorescence analysis. The proximal tail vertebrae of Turner's thick-toed gecko ( Chondrodactylus turneri) have been investigated for the first time by both histological and physical methods, including X-ray microtomography at different wavelengths and elemental analysis. This complex methodology of study made it possible to reveal the regions of accumulation of heavy elements in the aforementioned bones of Turner's thick-toed gecko.

  11. Transient x-ray absorption spectroscopy of hydrated halogen atom

    E-print Network

    Elles, Christopher G.; Shkrob, Ilya A.; Crowell, Robert A.; Arms, Dohn A.; Landahl, Eric C.

    2008-02-11

    Time-resolved x-ray absorption spectroscopy has been used to observe the transient species generated by one-photon detachment of an electron from aqueous bromide. The K-edge spectrum of the short-lived Br(0) atom exhibits a resonant 1s-4p transition...

  12. An x ray scatter approach for non-destructive chemical analysis of low atomic numbered elements

    NASA Technical Reports Server (NTRS)

    Ross, H. Richard

    1993-01-01

    A non-destructive x-ray scatter (XRS) approach has been developed, along with a rapid atomic scatter algorithm for the detection and analysis of low atomic-numbered elements in solids, powders, and liquids. The present method of energy dispersive x-ray fluorescence spectroscopy (EDXRF) makes the analysis of light elements (i.e., less than sodium; less than 11) extremely difficult. Detection and measurement become progressively worse as atomic numbers become smaller, due to a competing process called 'Auger Emission', which reduces fluorescent intensity, coupled with the high mass absorption coefficients exhibited by low energy x-rays, the detection and determination of low atomic-numbered elements by x-ray spectrometry is limited. However, an indirect approach based on the intensity ratio of Compton and Rayleigh scattered has been used to define light element components in alloys, plastics and other materials. This XRS technique provides qualitative and quantitative information about the overall constituents of a variety of samples.

  13. Note: Portable total reflection X-ray fluorescence spectrometer with small vacuum chamber

    NASA Astrophysics Data System (ADS)

    Kunimura, Shinsuke; Kudo, Shunpei; Nagai, Hiroki; Nakajima, Yoshihide; Ohmori, Hitoshi

    2013-04-01

    To improve the detection limits of a portable total reflection X-ray fluorescence (TXRF) spectrometer using white X-rays (i.e., both characteristic X-rays and continuum X-rays) from a 5 W X-ray tube, the measurement was performed in vacuum. The TXRF spectrum measured in vacuum was compared with that measured in air. The spectral background was significantly reduced when the scattering of the incident X-rays from air was reduced using a vacuum pump, leading to improvement in the detection limit. A detection limit of 8 pg was achieved for Cr when measuring in vacuum.

  14. The Application of X-Ray Fluorescence in Meteorite Investigation.

    NASA Astrophysics Data System (ADS)

    Sheesley, Christopher; Mehta, Rahul

    1996-03-01

    The project explored the use of X-Ray Fluorescence (XRF) in determining the composition and classification of meteoritic samples. Radioactive sources of Fe-55, Cm-244, and Am-241 were used to fluoresce the meteorite samples. A liquid nitrogen cooled ORTEC Si(Li) detector, with a 0.3 mil Be window, was used to detect the photons fluoresced from the sample. The data was collected and analyzed by a pentium based PCA III data acquisition system. Efficiency of the detector was determined by (i) measuring calibrated radioactive sources and by (ii) determining the attenuation of photons through the various layers of the detector. Determining the suitability of source and duration of fluorescence was an important part of detecting trace elements present in the meteorite samples. The Fe-55 source was found to be the best source to detect the silicates present in stony meteorites. While the Cm-244 source was found to be the best at detecting iron and nickel in the iron meteorites.

  15. X-ray fluorescence surface contaminant analyzer: A feasibility study

    NASA Technical Reports Server (NTRS)

    Eldridge, Hudson B.

    1988-01-01

    The bonding of liner material to the inner metal surfaces of solid rocket booster cases is adversely affected by minute amounts of impurities on the metal surface. Suitable non-destructive methods currently used for detecting these surface contaminants do not provide the means of identifying their elemental composition. The feasibility of using isotopic source excited energy dispersive X-ray fluorescence as a possible technique for elemental analysis of such contaminants is investigated. A survey is made of the elemental compositions of both D-6ac steel, a common construction material for the booster cases, and Conoco HD-2 grease, a common surface contamination. Source and detector choices that maximize signal to noise ratio in a Recessed Source Geometry are made. A Monte Carlo simulation is then made of the optimized device incorporating the latest available X-ray constants at the energy of the chosen source to determine the device's response to a D-6ac steel surface contained with Conoco HD-2 grease.

  16. Energy dispersive x-ray fluorescence analyzer with several x-ray tubes

    Microsoft Academic Search

    G. I. Borisov; R. I. Kondratenko; V. A. Mikhin; B. V. Odinov; A. V. Pukhov

    2005-01-01

    X-ray flurescent analyzer (XFA) has been developed and fabricated for determining sulphur, vanadium and nickel in oil. The instrument is equipped with three x-ray tubes with transmission Ti, Cu and Ag anodes, and aluminum, copper, and germanium filters, respectively, and one common switchable power supply. To excite characteristic radiation of determined elements, the characteristic radiation of the tube anode (titan,

  17. A soft x-ray fluorescence spectrometer at BESSY II

    NASA Astrophysics Data System (ADS)

    Follath, R.; Bischoff, P.; Eggenstein, F.; Noll, T.; Könnecke, R.; Schlappa, J.; Zeschke, T.

    2013-03-01

    A new spectrometer for resonant inelastic x-ray scattering experiments has been designed and is currently built at the synchrotron light facility BESSY II. The spectrometer with a total length of 3 m covers the photon energy range from 50 eV to 1000 eV with emphasis on the lower photon energy range. It is designed as plane grating spectrometer with two paraboloidal mirrors for collimation and focusing and a plane grating in-between. Two rotational degrees of freedom allow for a variation of the incidence and deflection angles at the grating. The geometrical acceptance of the spectrometer approaches a solid angle of 35 mrad × 40 mrad2 at low photon energies with a resolution better than 10 meV at 100 eV. A rotatable delay line detector is used to detect the fluorescence light in the line focus.

  18. Counter tube window and X-ray fluorescence analyzer study

    NASA Technical Reports Server (NTRS)

    Hertel, R.; Holm, M.

    1973-01-01

    A study was performed to determine the best design tube window and X-ray fluorescence analyzer for quantitative analysis of Venusian dust and condensates. The principal objective of the project was to develop the best counter tube window geometry for the sensing element of the instrument. This included formulation of a mathematical model of the window and optimization of its parameters. The proposed detector and instrument has several important features. The instrument will perform a near real-time analysis of dust in the Venusian atmosphere, and is capable of measuring dust layers less than 1 micron thick. In addition, wide dynamic measurement range will be provided to compensate for extreme variations in count rates. An integral pulse-height analyzer and memory accumulate data and read out spectra for detail computer analysis on the ground.

  19. Hyperspectral image reconstruction for x-ray fluorescence tomography.

    PubMed

    Gürsoy, Do?a; Biçer, Tekin; Lanzirotti, Antonio; Newville, Matthew G; De Carlo, Francesco

    2015-04-01

    A penalized maximum-likelihood estimation is proposed to perform hyperspectral (spatio-spectral) image reconstruction for X-ray fluorescence tomography. The approach minimizes a Poisson-based negative log-likelihood of the observed photon counts, and uses a penalty term that has the effect of encouraging local continuity of model parameter estimates in both spatial and spectral dimensions simultaneously. The performance of the reconstruction method is demonstrated with experimental data acquired from a seed of arabidopsis thaliana collected at the 13-ID-E microprobe beamline at the Advanced Photon Source. The resulting element distribution estimates with the proposed approach show significantly better reconstruction quality than the conventional analytical inversion approaches, and allows for a high data compression factor which can reduce data acquisition times remarkably. In particular, this technique provides the capability to tomographically reconstruct full energy dispersive spectra without compromising reconstruction artifacts that impact the interpretation of results. PMID:25968737

  20. Elemental analysis with x-ray fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Lienemann, Peter; Bleiner, Davide

    2012-01-01

    Elemental analysis by means of X-ray fluorescence (XRF) spectrometry is based on the element-specific electro- magnetic radiation induced as a consequence of inner-shell ionization. XRF spectrometry is ideal for the direct analysis of solid samples, but can also investigate fluid samples. On one side, these methods allow the rapid qualitative screening of unknown samples, without any particular sample preparation. On the other hand, it is possible to perform the fully automated quantitative analysis of large sample sets. Further figures of merit are the 'standard-less' analysis of samples in a non-destructive mode, and detection down to 0.01 %. The availability of portable XRF systems6 is a further advantage for on-site measurements. The fundamentals are discussed to orient the user, and a survey of instrumental capabilities is provided.

  1. Analysis of tungsten carbides by X-ray fluorescence spectrometry.

    PubMed

    Kinson, K; Knott, A C; Belcher, C B

    Five sample presentation techniques were examined for the X-ray fluorescence spectrometric analysis of tungsten carbide alloys in powder and cemented forms. Powder samples may be oxidized by air at 600 degrees before fusion (I), or preferably by lithium nitrate during fusion (II); the fusion is effected with lithium-lanthanum tetraborate followed by briquetting with graphite. Powder samples may also be blended with wax and briquetted (III). Cemented carbides are surface-prepared with silicon carbide before analysis (V). Briquettes prepared by blending carbide powder, lithium-lanthanum tetraborate and graphite (IV), give poor reproducibility, however, owing to micro-absorption effects the technique is not recommended. The determination of eight common elements in tungsten carbide is discussed and the relative standard deviations are 0.002-0.004 for major and 0.008-0.01 for minor elements. PMID:18961988

  2. Materials characterization using micro-x-ray fluorescence elemental imaging.

    SciTech Connect

    Havrilla, G. J. (George J.); Miller, T. C. (Thomasin C.); Joseph, M. R. (Martha R.)

    2002-01-01

    Materials characterization continues to be a key challenge in a variety of programs. Although bulk elemental composition provides overall concentration of both major and trace elements, the distribution of these elements both on micro and macro scales can determine the performance and ultimately the physical properties of the materials. Hence elemental imaging can provide a new level of information for major and in some cases bulk trace concentrations of elements. Micro X-ray fluorescence (MXRF) offers unique capabilities in terms of elemental imaging. This approach is based on a meso scale level of resolution around 50 micrometer X-ray spot size. When coupled with a moveable stage, specimens several inches on a side can be imaged with surprising detail. In most instances, qualitative images are sufficient to illustrate the elemental heterogeneity. This information can then be used to determine if the material meets the desired physical characteristics and whether this is due to the observed heterogeneity or in spite of it. Several examples of elemental imaging will be presented. These will include the aging of polymers and the effects of residual organotin catalyst. The tin can be imaged using MXRF and has been show to be mobile within the polymeric material over time. Corrosion is a serious issue throughout the industrial world. A specific example of chloride attack on a metal, which creates problems in waste storage. Finally, MXRF used in high throughput screening in the development of novel peptide receptors will be shown. The advantage of MXRF is that no fluorescent tags need be added to the target molecules. This insures the unhindered interaction of the target molecules and allows for additional characterization using molecular spectroscopic techniques.

  3. Promising X-ray fluorescence tests for superconducting tunneljunction detector

    SciTech Connect

    Friedrich, Stephan; Robinson, Arthur L.

    2001-05-15

    Scientists in the Physical Biosciences Division of the Ernest Orlando Berkeley National Laboratory (Berkeley Lab) studying transition metals in proteins with fluorescence-detected L-edge absorption spectroscopy have found the measurements to be extremely challenging. The difficulty is that the metal centers are present in very dilute concentrations so that their weak fluorescence is often obscured by strong background signals carbon and oxygen. To solve this problem, the Berkeley group has been working with researchers from the Advanced Detector Group at the Lawrence Livermore National Laboratory on an energy-dispersive superconducting tunnel junction x-ray detector. These devices in principle have the energy resolution needed to reveal the metal signal. The most recent results with the latest version of the detector on Beamline 4.0.1-2 at the Advanced Light Source (ALS) illustrate the promise of the cryogenic detector strategy not only for this application but also for spectroscopy of other types of dilute samples. Transition-metal complexes are key elements in many biologically important processes that are catalyzed by proteins (enzymes), photosynthesis being a prime example. The changes in that occur in electronic structure throughout a catalytic cycle are the subject of much research aimed at understanding the mechanisms of these processes. L-edge x-ray spectroscopy offers several advantages relative to the more common K-edge techniques, since it involves allowed transitions to the d-orbitals associated with metal-ligand bonding. It also has a rich multiplet structure interpretable by theory and higher spectral resolution.

  4. Atomic Processes in X-ray Photoioinzed Gas

    NASA Technical Reports Server (NTRS)

    Kallman, Timothy

    2005-01-01

    It has long been known that photoionization and photoabsorption play a dominant role in determining the state of gas in nebulae surrounding hot stars and in active galaxies. Recent observations of X-ray spectra demonstrate that these processes are also dominant in highly ionized gas near compact objects, and also affect the transmission of X-rays from the majority of astronomical sources. This has led to new insights into the understanding of what is going on in these sources. It has also pointed out the need for accurate atomic cross sections for photoionization and absorption, notably for processes involving inner shells. The xstar code can be used for calculating the heating, ionization and reprocessing of X-rays by gas in a range of ionization states and temperatures. It has recently been updated to include an improved treatment of inner shell transitions in iron. I will review the capabilities of xstar, the atomic data, and illustrate some applications to recent X-ray spectral observations.

  5. MESSENGER X-Ray Spectrometer Detection of Electron-Induced X-Ray Fluorescence from Mercury's Surface

    NASA Astrophysics Data System (ADS)

    Starr, R. D.; Nittler, L. R.; Weider, S. Z.; Rhodes, E. A.; Schriver, D.; Schlemm, C. E.; Solomon, S. C.

    2012-03-01

    X-ray emissions observed from the dark side of Mercury are the result of ~1-10 keV electrons impinging on the planet’s surface. Knowledge of the precipitating electron distribution makes it possible to infer surface composition from the measured fluorescent spectra.

  6. Flow method and apparatus for screening chemicals using micro x-ray fluorescence

    DOEpatents

    Warner, Benjamin P. (Los Alamos, NM); Havrilla, George J. (Los Alamos, NM); Miller, Thomasin C. (Bartlesville, OK); Lewis, Cris (Los Alamos, NM); Mahan, Cynthia A. (Los Alamos, NM); Wells, Cyndi A. (Los Alamos, NM)

    2011-04-26

    Method and apparatus for screening chemicals using micro x-ray fluorescence. A method for screening a mixture of potential pharmaceutical chemicals for binding to at least one target binder involves flow separating a solution of chemicals and target binders into separated components, exposing them to an x-ray excitation beam, detecting x-ray fluorescence signals from the components, and determining from the signals whether or not a binding event between a chemical and target binder has occurred.

  7. Flow method and apparatus for screening chemicals using micro x-ray fluorescence

    DOEpatents

    Warner, Benjamin P. (Los Alamos, NM); Havrilla, George J. (Los Alamos, NM); Miller, Thomasin C. (Bartlesville, OK); Lewis, Cris (Los Alamos, NM); Mahan, Cynthia A. (Los Alamos, NM); Wells, Cyndi A. (Los Alamos, NM)

    2009-04-14

    Method and apparatus for screening chemicals using micro x-ray fluorescence. A method for screening a mixture of potential pharmaceutical chemicals for binding to at least one target binder involves flow-separating a solution of chemicals and target binders into separated components, exposing them to an x-ray excitation beam, detecting x-ray fluorescence signals from the components, and determining from the signals whether or not a binding event between a chemical and target binder has occurred.

  8. Atomic-scale X-ray structural analysis of self-assembled monolayers on Silicon

    NASA Astrophysics Data System (ADS)

    Lin, J.-C.; Kellar, J. A.; Kim, J.-H.; Yoder, N. L.; Bevan, K. H.; Nguyen, S. T.; Hersam, M. C.; Bedzyk, M. J.

    2009-02-01

    Two related self-assembled monolayers (SAMs), 4-bromostyrene (BrSty) and 4-bromophenylacetylene (BPA), are photochemically grown from solution on to the monohydride-terminated Si(111) surface. The atomic-scale structures of the resulting SAMs are examined by X-ray standing waves (XSW), X-ray reflectivity (XRR), X-ray fluorescence, atomic-force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT). The coverage is 0.5 ML. The results show that in each case the molecule covalently bonds to a single Si T1 site and stands up-right with a slight molecular tilt of 17? that leaves the Br terminal end over a neighboring T4 site. The Br height is 8.5 Å (BrSty) and 8.6 Å (BPA) above the top surface Si atom. The combined XSW and XRR results rule-out two alternative bonding models predicted by DFT that have the root of the molecule bonded to two neighboring top Si surface atoms. Based on the XSW 111 and 333 coherent fractions, the BPA/Si(111) has a reduced vertical Br distribution width in comparison to BrSty. This greater rigidity in the molecular structure is correlated to a C=C bond at the root.

  9. Atomic-scale X-ray structural analysis of self-assembled monolayers on Silicon

    SciTech Connect

    Lin, J.-C.; Kellar, J.A.; Kim, J.-H.; Yoder, N.L.; Bevan, K.H.; Nguyen, S.T.; Hersam, M.C.; Bedzyk, M.J.; (NWU); (Purdue)

    2009-04-02

    Two related self-assembled monolayers (SAMs), 4-bromostyrene (BrSty) and 4-bromophenylacetylene (BPA), are photochemically grown from solution on to the monohydride-terminated Si(111) surface. The atomic-scale structures of the resulting SAMs are examined by X-ray standing waves (XSW), X-ray reflectivity (XRR), X-ray fluorescence, atomic-force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT). The coverage is 0.5 ML. The results show that in each case the molecule covalently bonds to a single Si T{sub 1} site and stands up-right with a slight molecular tilt of 17{sup o} that leaves the Br terminal end over a neighboring T{sub 4} site. The Br height is 8.5 {angstrom} (BrSty) and 8.6 {angstrom} (BPA) above the top surface Si atom. The combined XSW and XRR results rule-out two alternative bonding models predicted by DFT that have the root of the molecule bonded to two neighboring top Si surface atoms. Based on the XSW 111 and 333 coherent fractions, the BPA/Si(111) has a reduced vertical Br distribution width in comparison to BrSty. This greater rigidity in the molecular structure is correlated to a C=C bond at the root.

  10. In Vivo X-Ray Fluorescence Microtomographic Imaging of Elements in Single-Celled Fern Spores

    SciTech Connect

    Hirai, Yasuharu; Yoneyama, Akio; Hisada, Akiko [Advanced Research Laboratory, Hitachi, Ltd., Hatoyama, Saitama 350-0395 (Japan); Uchida, Kenko [Central Research Laboratory, Hitachi, Ltd., Kokubunji, Tokyo 185-8601 (Japan)

    2007-01-19

    We have observed in vivo three-dimensional distributions of constituent elements of single-celled spores of the fern Adiantum capillus-veneris using an X-ray fluorescence computed microtomography method. The images of these distributions are generated from a series of slice data, each of which is acquired by a sample translation-rotation method. An incident X-ray microbeam irradiates the sample with a spot size of 1 {mu}m. The high Ca concentration in the testa and the localized and overlapping Fe and Zn concentrations inside the spore are shown in three-dimensional images. The K concentration is high throughout the cell, and there are localized regions of higher density. The atomic number densities of these elements in the testa and inside the cell in a tomographic slice are estimated with a resolution of about 1 {mu}m.

  11. Advances in X-Ray Chemical Analysis, Japan, 41 (2010) ISSN 0911-7806 Portable Total Reflection X-Ray Fluorescence Spectrometer

    E-print Network

    Jun, Kawai

    2010-01-01

    Advances in X-Ray Chemical Analysis, Japan, 41 (2010) ISSN 0911-7806 © X Portable Total Reflection X-Ray Fluorescence Spectrometer for Ultra Trace Elemental Determination Shinsuke KUNIMURA and Jun KAWAI #12;#12;41 29 X Adv. X-Ray. Chem. Anal., Japan 41, pp.29-44 (2010) 606-8501 X Portable Total

  12. Atomic physics modeling of x-ray laser plasmas

    SciTech Connect

    Osterheld, A.L.; Young, B.K.F.; Walling, R.S.; Goldstein, W.H.; Scofield, J.H.; Chen, M.; Shimkaveg, G.; Carter, M.; Shepherd, R.; MacGowan, B.J.; Da Silva, L.; Matthews, D.; Maxon, S.; London, R.; Stewart, R.E.

    1992-05-01

    We have developed collisional-radiative models to describe the kinetics of x-ray laser plasmas. Careful attention has been paid to indirect processes such as dielectronic recombination and excitation-autoionization. These models can be used for calculations of the ionization dynamics, gain coefficients, and detailed emission spectra. We will present results from ionization balance and gain calculations for neonlike and nickellike collisional lasing schemes, emphasizing the effects of different atomic physics processes and model approximations.

  13. Dual x-ray fluorescence spectrometer and method for fluid analysis

    DOEpatents

    Wilson, Bary W.; Shepard, Chester L.

    2005-02-22

    Disclosed are an X-ray fluorescence (SRF) spectrometer and method for on-site and in-line determination of contaminant elements in lubricating oils and in fuel oils on board a marine vessel. An XRF source block 13 contains two radionuclide sources 16, 17 (e.g. Cd 109 and Fe 55), each oriented 180 degrees from the other to excite separate targets. The Cd 109 source 16 excites sample lube oil flowing through a low molecular weight sample line 18. The Fe 55 source 17 excites fuel oil manually presented to the source beam inside a low molecular weight vial 26 or other container. Two separate detectors A and B are arranged to detect the fluorescent x-rays from the targets, photons from the analyte atoms in the lube oil for example, and sulfur identifying x-rays from bunker fuel oil for example. The system allows both automated in-line and manual on-site analysis using one set of signal processing and multi-channel analyzer electronics 34, 37 as well as one computer 39 and user interface 43.

  14. Measurement of plutonium in spent nuclear fuel by self-induced x-ray fluorescence

    SciTech Connect

    Hoover, Andrew S [Los Alamos National Laboratory; Rudy, Cliff R [Los Alamos National Laboratory; Tobin, Steve J [Los Alamos National Laboratory; Charlton, William S [Los Alamos National Laboratory; Stafford, A [TEXAS A& M; Strohmeyer, D [TEXAS A& M; Saavadra, S [ORNL

    2009-01-01

    Direct measurement of the plutonium content in spent nuclear fuel is a challenging problem in non-destructive assay. The very high gamma-ray flux from fission product isotopes overwhelms the weaker gamma-ray emissions from plutonium and uranium, making passive gamma-ray measurements impossible. However, the intense fission product radiation is effective at exciting plutonium and uranium atoms, resulting in subsequent fluorescence X-ray emission. K-shell X-rays in the 100 keV energy range can escape the fuel and cladding, providing a direct signal from uranium and plutonium that can be measured with a standard germanium detector. The measured plutonium to uranium elemental ratio can be used to compute the plutonium content of the fuel. The technique can potentially provide a passive, non-destructive assay tool for determining plutonium content in spent fuel. In this paper, we discuss recent non-destructive measurements of plutonium X-ray fluorescence (XRF) signatures from pressurized water reactor spent fuel rods. We also discuss how emerging new technologies, like very high energy resolution microcalorimeter detectors, might be applied to XRF measurements.

  15. Trace element determination in drugs by total-reflection X-ray fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Wagner, M.; Rostam-Khani, P.; Wittershagen, A.; Rittmeyer, Claudia; Kolbesen, B. O.; Hoffmann, H.

    1997-07-01

    The capability of total-reflection X-ray fluorescence spectrometry (TXRF) for the determination of trace elements in drugs is described. Various samples of lecithin, insulin, procaine and tryptophan of different origin were investigated. The element concentrations provide element fingerprints which offer the possibility to discriminate between different batches of the analysed substances originating from different production or purification processes. TXRF facilitates the characterization of such samples without extensive pre-treatment, and provides fast multi-element determination of elements with atomic numbers 14< Z<92 based on matrix-independent quantification by means of an internal standard.

  16. An improved double fluorescence detector for fluorescence EXAFS (Extended X-ray Absorption Fine Structure) measurements

    SciTech Connect

    Heald, S.M.

    1988-01-01

    In many cases the fluorescence EXAFS signal is contaminated with fluorescence from nearby elements. If this fluorescence is of lower energy than the element of interest, x-ray filters are not effective. One method for dealing with this problem is the double fluorescence method described by Wong and Rao. This paper describes an improved version of this double fluorescence scheme which greatly improves its efficiency. Data are presented for a sample of 1/2% Hf in Ni/sub 3/Al, and 1.6% CuO in NiO. When standard fluorescence is used, both signals are almost completely obscured by the approx. =100X larger Ni K fluorescence signal. With the double fluorescence detector the Hf L/sub 3/ and Cu K-edge signals are clearly observed and good spectra can be obtained in about an hour. 4 refs., 4 figs.

  17. Resonant X-ray fluorescence spectroscopy at the V L-edges of vanadium oxides

    SciTech Connect

    Duda, L.C.; Stagarescu, C.B. [Boston Univ., MA (United States). Dept. of Physics; Downes, J.E.; Smith, K.E.; Draeger, G. [Martin-Luther-Univ., Halle (Germany)

    1998-12-31

    The authors have studied resonant V L{sub {alpha}}-fluorescence spectra of vanadium oxides with V in several different oxidation states. The spectra are dominated by the O 2p-contribution centered at about 6 eV below the top of the valence band (VB-top). The V 3d-contribution, found close to the VB-top, increases with decreasing valency of the vanadium atoms. Resonant inelastic (Raman) x-ray scattering is fairly weak in these compounds and overlaps with the ordinary fluorescence spectrum. Large spectral changes of V L{sub {alpha}}-fluorescence in the metal-insulator transition of V{sub 2}O{sub 3} have been observed.

  18. Observation of correlated X-ray scattering at atomic resolution.

    PubMed

    Mendez, Derek; Lane, Thomas J; Sung, Jongmin; Sellberg, Jonas; Levard, Clément; Watkins, Herschel; Cohen, Aina E; Soltis, Michael; Sutton, Shirley; Spudich, James; Pande, Vijay; Ratner, Daniel; Doniach, Sebastian

    2014-07-17

    Tools to study disordered systems with local structural order, such as proteins in solution, remain limited. Such understanding is essential for e.g. rational drug design. Correlated X-ray scattering (CXS) has recently attracted new interest as a way to leverage next-generation light sources to study such disordered matter. The CXS experiment measures angular correlations of the intensity caused by the scattering of X-rays from an ensemble of identical particles, with disordered orientation and position. Averaging over 15 496 snapshot images obtained by exposing a sample of silver nanoparticles in solution to a micro-focused synchrotron radiation beam, we report on experimental efforts to obtain CXS signal from an ensemble in three dimensions. A correlation function was measured at wide angles corresponding to atomic resolution that matches theoretical predictions. These preliminary results suggest that other CXS experiments on disordered ensembles--such as proteins in solution--may be feasible in the future. PMID:24914148

  19. Nonlinear Atomic Response to Intense Ultrashort X Rays

    SciTech Connect

    Doumy, G. [Ohio State University, Columbus, Ohio 43210 (United States)] [Argonne National Laboratory, Argonne, Illinois 60439 (United States); Roedig, C.; Blaga, C. I.; DiChiara, A. D.; Agostini, P.; DiMauro, L. F. [Ohio State University, Columbus, Ohio 43210 (United States); Son, S.-K. [Center for Free-Electron Laser Science, DESY, 22607 Hamburg (Germany); Santra, R. [Center for Free-Electron Laser Science, DESY, 22607 Hamburg (Germany)] [Department of Physics, University of Hamburg, 20355 Hamburg (Germany); Berrah, N.; Fang, L.; Hoener, M. [Western Michigan University, Kalamazoo, Michigan 49008 (United States); Bostedt, C.; Bozek, J. D.; Messerschmidt, M. [Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Bucksbaum, P. H.; Cryan, J. P.; Ghimire, S.; Glownia, J. M.; Reis, D. A. [Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Kanter, E. P. [Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2011-02-25

    The nonlinear absorption mechanisms of neon atoms to intense, femtosecond kilovolt x rays are investigated. The production of Ne{sup 9+} is observed at x-ray frequencies below the Ne{sup 8+}, 1s{sup 2} absorption edge and demonstrates a clear quadratic dependence on fluence. Theoretical analysis shows that the production is a combination of the two-photon ionization of Ne{sup 8+} ground state and a high-order sequential process involving single-photon production and ionization of transient excited states on a time scale faster than the Auger decay. We find that the nonlinear direct two-photon ionization cross section is orders of magnitude higher than expected from previous calculations.

  20. Atomic Processes in X-ray Photoionized Gas

    NASA Technical Reports Server (NTRS)

    Kallman, Timothy

    2005-01-01

    It has long been known that photoionization and photoabsorption play a dominant role in determining the state of gas in nebulae surrounding hot stars and in active galaxies. Recent observations of X-ray spectra demonstrate that these processes are also dominant in highly ionized gas near compact objects, and also affect the transmission of X-rays from the majority of astronomical sources. This has led to new insights into the understanding of what is going on in these sources. It has also pointed out the need for a better atomic cross sections for photoionization and absorption, notably for processes involving inner shells. In this talk I will discuss these issues, what is known and where more work is needed.

  1. Observation of correlated X-ray scattering at atomic resolution

    PubMed Central

    Mendez, Derek; Lane, Thomas J.; Sung, Jongmin; Sellberg, Jonas; Levard, Clément; Watkins, Herschel; Cohen, Aina E.; Soltis, Michael; Sutton, Shirley; Spudich, James; Pande, Vijay; Ratner, Daniel; Doniach, Sebastian

    2014-01-01

    Tools to study disordered systems with local structural order, such as proteins in solution, remain limited. Such understanding is essential for e.g. rational drug design. Correlated X-ray scattering (CXS) has recently attracted new interest as a way to leverage next-generation light sources to study such disordered matter. The CXS experiment measures angular correlations of the intensity caused by the scattering of X-rays from an ensemble of identical particles, with disordered orientation and position. Averaging over 15 496 snapshot images obtained by exposing a sample of silver nanoparticles in solution to a micro-focused synchrotron radiation beam, we report on experimental efforts to obtain CXS signal from an ensemble in three dimensions. A correlation function was measured at wide angles corresponding to atomic resolution that matches theoretical predictions. These preliminary results suggest that other CXS experiments on disordered ensembles—such as proteins in solution—may be feasible in the future. PMID:24914148

  2. Three dimensional subsurface elemental identification of minerals using confocal micro-X-ray fluorescence and micro-X-ray computed tomography

    NASA Astrophysics Data System (ADS)

    Cordes, Nikolaus L.; Seshadri, Srivatsan; Havrilla, George J.; Yuan, Xiaoli; Feser, Michael; Patterson, Brian M.

    2015-01-01

    Current non-destructive elemental characterization methods, such as scanning electron microscopy-based energy dispersive spectroscopy (SEM-EDS) and micro-X-ray fluorescence spectroscopy (MXRF), are limited to either elemental identification at the surface (SEM-EDS) or suffer from an inability to discriminate between surface or depth information (MXRF). Thus, a non-destructive elemental characterization of individual embedded particles beneath the surface is impossible with either of these techniques. This limitation can be overcome by using laboratory-based 3D confocal micro-X-ray fluorescence spectroscopy (confocal MXRF). This technique utilizes focusing optics on the X-ray source and detector which allows for spatial discrimination in all three dimensions. However, the voxel-by-voxel serial acquisition of a 3D elemental scan can be very time-intensive (~ 1 to 4 weeks) if it is necessary to locate individual embedded particles of interest. As an example, if each point takes a 5 s measurement time, a small volume of 50 × 50 × 50 pixels leads to an acquisition time of approximately 174 h, not including sample stage movement time. Initially screening the samples for particles of interest using micro-X-ray computed tomography (micro-CT) can significantly reduce the time required to spatially locate these particles. Once located, these individual particles can be elementally characterized with confocal MXRF. Herein, we report the elemental identification of high atomic number surface and subsurface particles embedded in a mineralogical matrix by coupling micro-CT and confocal MXRF. Synergistically, these two X-ray based techniques first rapidly locate and then elementally identify individual subsurface particles.

  3. Energy response calibration of photon-counting detectors using x-ray fluorescence: a feasibility study

    NASA Astrophysics Data System (ADS)

    Cho, H.-M.; Ding, H.; Ziemer, BP; Molloi, S.

    2014-12-01

    Accurate energy calibration is critical for the application of energy-resolved photon-counting detectors in spectral imaging. The aim of this study is to investigate the feasibility of energy response calibration and characterization of a photon-counting detector using x-ray fluorescence. A comprehensive Monte Carlo simulation study was performed using Geant4 Application for Tomographic Emission (GATE) to investigate the optimal technique for x-ray fluorescence calibration. Simulations were conducted using a 100?kVp tungsten-anode spectra with 2.7?mm Al filter for a single pixel cadmium telluride (CdTe) detector with 3? × ?3?mm2 in detection area. The angular dependence of x-ray fluorescence and scatter background was investigated by varying the detection angle from 20° to 170° with respect to the beam direction. The effects of the detector material, shape, and size on the recorded x-ray fluorescence were investigated. The fluorescent material size effect was considered with and without the container for the fluorescent material. In order to provide validation for the simulation result, the angular dependence of x-ray fluorescence from five fluorescent materials was experimentally measured using a spectrometer. Finally, eleven of the fluorescent materials were used for energy calibration of a CZT-based photon-counting detector. The optimal detection angle was determined to be approximately at 120° with respect to the beam direction, which showed the highest fluorescence to scatter ratio (FSR) with a weak dependence on the fluorescent material size. The feasibility of x-ray fluorescence for energy calibration of photon-counting detectors in the diagnostic x-ray energy range was verified by successfully calibrating the energy response of a CZT-based photon-counting detector. The results of this study can be used as a guideline to implement the x-ray fluorescence calibration method for photon-counting detectors in a typical imaging laboratory.

  4. Portable x-ray fluorescence spectrometer. Innovative technology summary report

    SciTech Connect

    NONE

    1998-12-01

    This report describes the application of portable X-ray fluorescence (XRF) spectrometry to characterize materials related to deactivation and decommissioning (D and D) of contaminated facilities. Two portable XRF instruments manufactured by TN Spectrace were used in a technology evaluation as part of the Large-Scale Demonstration Project (LSDP) held at the Chicago Pile-5 Research Reactor (CP-5) located at Argonne National Laboratory (ANL). The LSDP is sponsored by the US Department of Energy (DOE), Office of Science and Technology, Deactivation and Decommissioning Focus Are (DDFA). The objective of the LSDP is to demonstrate innovative technologies or technology applications potentially beneficial to the D and D of contaminated facilities. The portable XRF technology offers several potential benefits for rapid characterization of facility components and contaminants, including significant cost reduction, fast turnaround time,a nd virtually no secondary waste. Field work for the demonstration of the portable XRF technology was performed from August 28--September 3, 1996 and October 30--December 13, 1996.

  5. High-throughput screening with micro-x-ray fluorescence

    SciTech Connect

    Havrilla, George J.; Miller, Thomasin C. [Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); X-ray Optical Systems, Inc., East Greenbush, New York 12061 (United States)

    2005-06-15

    Micro-x-ray fluorescence (MXRF) is a useful characterization tool for high-throughput screening of combinatorial libraries. Due to the increasing threat of use of chemical warfare (CW) agents both in military actions and against civilians by terrorist extremists, there is a strong push to improve existing methods and develop means for the detection of a broad spectrum of CW agents in a minimal amount of time to increase national security. This paper describes a combinatorial high-throughput screening technique for CW receptor discovery to aid in sensor development. MXRF can screen materials for elemental composition at the mesoscale level (tens to hundreds of micrometers). The key aspect of this work is the use of commercial MXRF instrumentation coupled with the inherent heteroatom elements within the target molecules of the combinatorial reaction to provide rapid and specific identification of lead species. The method is demonstrated by screening an 11-mer oligopeptide library for selective binding of the degradation products of the nerve agent VX. The identified oligopeptides can be used as selective molecular receptors for sensor development. The MXRF screening method is nondestructive, requires minimal sample preparation or special tags for analysis, and the screening time depends on the desired sensitivity.

  6. Continuous Flow Cryostat for X-Ray Fluorescence

    SciTech Connect

    Weng, T.-C.; Linden, Peter J. E. M. van der; Glatzel, Pieter; Lapras, Christophe [ESRF, 6 rue Jules Horowitz, F-38043 Grenoble (France); Krzyzowski, Michael [CryoVac GMbH and Co KG, Heuserweg 14, D-53482 Troisdorf (Germany)

    2010-06-23

    A continuous Helium flow cryostat was designed and built by Cryovac GMbH to specifications given by ESRF beamline ID26. The beamline has constructed a high energy resolution X-ray emission spectrometer using multiple spherically bent analyser crystals, together with the sample and detector on a vertical Rowland circle. The double shrouded cryostat has a low profile designed to fit into the spectrometer setup, the lowest detector position allows for a Bragg angle of 85 degrees with a 1 meter diameter Rowland circle. The cryostat has a temperature range of 5 to 300 Kelvin on the sample holder which is cooled by static Helium exchange gas. The cryostat has triple windows for beam entrance, transmission and fluorescence; the latter offers an opening angle of 80 degrees horizontally and 50 degrees vertically. The cryostat can be configured to work in two different operation modes: translation or rotation. The translation mode offers a displacement of 50 mm to accommodate multiple samples on the sample holder. The rotation mode is used for polarisation studies on single crystals.We show recent results obtained on Chromium containing molecular complexes; data collection was done at a temperature of 10 Kelvin to avoid radiation damage.

  7. Combined synchrotron X-ray tomography and X-ray powder diffraction using a fluorescing metal foil

    NASA Astrophysics Data System (ADS)

    Kappen, P.; Arhatari, B. D.; Luu, M. B.; Balaur, E.; Caradoc-Davies, T.

    2013-06-01

    This study realizes the concept of simultaneous micro-X-ray computed tomography and X-ray powder diffraction using a synchrotron beamline. A thin zinc metal foil was placed in the primary, monochromatic synchrotron beam to generate a divergent wave to propagate through the samples of interest onto a CCD detector for tomographic imaging, thus removing the need for large beam illumination and high spatial resolution detection. Both low density materials (kapton tubing and a piece of plant) and higher density materials (Egyptian faience) were investigated, and elemental contrast was explored for the example of Cu and Ni meshes. The viability of parallel powder diffraction using the direct beam transmitted through the foil was demonstrated. The outcomes of this study enable further development of the technique towards in situ tomography/diffraction studies combining micrometer and crystallographic length scales, and towards elemental contrast imaging and reconstruction methods using well defined fluorescence outputs from combinations of known fluorescence targets (elements).

  8. Combined synchrotron X-ray tomography and X-ray powder diffraction using a fluorescing metal foil

    SciTech Connect

    Kappen, P. [Department of Physics, La Trobe University, Victoria 3086 (Australia); Arhatari, B. D.; Luu, M. B.; Balaur, E. [Department of Physics, La Trobe University, Victoria 3086 (Australia); ARC Centre of Excellence for Coherent X-ray Science, Melbourne (Australia); Caradoc-Davies, T. [Australian Synchrotron, 800 Blackburn Road, Victoria 3168 (Australia)

    2013-06-15

    This study realizes the concept of simultaneous micro-X-ray computed tomography and X-ray powder diffraction using a synchrotron beamline. A thin zinc metal foil was placed in the primary, monochromatic synchrotron beam to generate a divergent wave to propagate through the samples of interest onto a CCD detector for tomographic imaging, thus removing the need for large beam illumination and high spatial resolution detection. Both low density materials (kapton tubing and a piece of plant) and higher density materials (Egyptian faience) were investigated, and elemental contrast was explored for the example of Cu and Ni meshes. The viability of parallel powder diffraction using the direct beam transmitted through the foil was demonstrated. The outcomes of this study enable further development of the technique towards in situ tomography/diffraction studies combining micrometer and crystallographic length scales, and towards elemental contrast imaging and reconstruction methods using well defined fluorescence outputs from combinations of known fluorescence targets (elements).

  9. Combined synchrotron X-ray tomography and X-ray powder diffraction using a fluorescing metal foil.

    PubMed

    Kappen, P; Arhatari, B D; Luu, M B; Balaur, E; Caradoc-Davies, T

    2013-06-01

    This study realizes the concept of simultaneous micro-X-ray computed tomography and X-ray powder diffraction using a synchrotron beamline. A thin zinc metal foil was placed in the primary, monochromatic synchrotron beam to generate a divergent wave to propagate through the samples of interest onto a CCD detector for tomographic imaging, thus removing the need for large beam illumination and high spatial resolution detection. Both low density materials (kapton tubing and a piece of plant) and higher density materials (Egyptian faience) were investigated, and elemental contrast was explored for the example of Cu and Ni meshes. The viability of parallel powder diffraction using the direct beam transmitted through the foil was demonstrated. The outcomes of this study enable further development of the technique towards in situ tomography?diffraction studies combining micrometer and crystallographic length scales, and towards elemental contrast imaging and reconstruction methods using well defined fluorescence outputs from combinations of known fluorescence targets (elements). PMID:23822348

  10. Determination of the implantation dose in silicon wafers by X-ray fluorescence analysis

    SciTech Connect

    Klockenkaemper, R.; Becker, M.; Bubert, H.; Burba, P. (Institut fuer Spektrochemie und Angewandte Spektroskopie, Dortmund (West Germany)); Palmetshofer, L. (Johannes-Kepler-Universitaet, Linz (Austria))

    1990-08-01

    The ion dose implanted in silicon wafers was determined by X-ray fluorescence analysis after the implantation process. As only near-surface layers below 1-{mu}m thickness were considered, the calibration could be carried out with external standards consisting of thin films of doped gelatine spread on pure wafers. Dose values for Cr and Co were determined between 4 {times} 10{sup 15} and 2 {times} 10{sup 17} atoms/cm{sup 2}, the detection limits being about 3 {times} 10{sup 14} atoms/cm{sup 2}. The results are precise and accurate apart from a residual scatter of less than 7%. This was confirmed by flame atomic absorption spectrometry after volatilization of the silicon matrix as SiF{sub 4}. It was found that ion-current measurements carried out during the implantation process can have considerable systematic errors.

  11. The fluorescence-dominated X-ray spectrum of the spiral galaxy NGC 6552

    NASA Technical Reports Server (NTRS)

    Fukazawa, Yasushi; Makishima, Kazuo; Ebisawa, Ken; Fabian, Andrew C.; Gendreau, Keith C.; Ikebe, Yasushi; Iwasawa, Kazushi; Kii, Tsuneo; Mushotzky, Richard F.; Ohashi, Takaya

    1994-01-01

    A hard X-ray source with a 2-10 keV flux of approximately 6 x 10(exp -13) ergs/sec/sq cm was detected with ASCA in the north ecliptic pole region. It is identified with the spiral galaxy NGC 6552 at a redshift of z = 0.026, which is optically classified as a Seyfert 2 galaxy. The X-ray spectrum consists of a series of atomic K-emission lines from (nearly-) neutral species of at least seven abundant elements, and a heavily absorbed (N(sub H) approx. = 6 x 10(exp 23)/sq cm) hard continuum. The iron line has an equivalent width as large as approximately 0.9 keV. Our results show that NGC 6552 is an extreme type 2 Seyfert galaxy, in which the fluorescent lines are produced when hard X-rays from a hidden active nucleus are reflected off thick cool matter into our line of sight. The intrinsic 2-10 keV luminosity of the nucleus is estimated to be at least 6 x 10(exp 42) ergs/s.

  12. Nuclear surface studies with antiprotonic atom X-rays

    E-print Network

    S. Wycech; F. J. Hartmann; J. Jastrzebski; B. Klos; A. Trzcinska; T. von Egidy

    2007-02-08

    The recent and older level shifts and widths in pbar atoms are analyzed. The results are fitted by an antiproton-nucleus optical potential with two basic complex strength parameters. These parameters are related to average S and P wave scattering parameters in the subthreshold energy region. A fair consistency of the X-ray data for all Z values, stopping pbar data and the Nbar-N scattering data has been achieved. The determination of neutron density profiles at the nuclear surface is undertaken, and the determination of the neutron R_{rms} radii is attempted. Uncertainties due to the input data and the procedure are discussed.

  13. X-ray Peltier cooled detectors for X-ray fluorescence analysis

    Microsoft Academic Search

    A. Loupilov; A. Sokolov; V. Gostilo

    2001-01-01

    The recent results on development of X-ray Si(Li), Si-planar and CdTe p-i-n detectors cooled by Peltier coolers for fabrication of laboratory and portable XRF analysers for different applications are discussed.Low detection limits of XRF analysers are provided by increasing of detectors sensitive surface; improvement of their spectrometrical characteristics; decreasing of front-end-electronics noise level; Peltier coolers and vacuum chambers cooling modes

  14. Energy dispersive x-ray fluorescence analyzer with several x-ray tubes

    NASA Astrophysics Data System (ADS)

    Borisov, G. I.; Kondratenko, R. I.; Mikhin, V. A.; Odinov, B. V.; Pukhov, A. V.

    2005-07-01

    X-ray flurescent analyzer (XFA) has been developed and fabricated for determining sulphur, vanadium and nickel in oil. The instrument is equipped with three x-ray tubes with transmission Ti, Cu and Ag anodes, and aluminum, copper, and germanium filters, respectively, and one common switchable power supply. To excite characteristic radiation of determined elements, the characteristic radiation of the tube anode (titan, copper) is used, or the charactersitic radiation of the filter (germanium). XFA is fitted with one small-size electrically cooled semiconductor detector. The measuring device is based on a wide-angle geometry of characteristic radiation excitation and registration, where the x-ray tube focus illuminates the sample, and the registering detector 'sees' the illuminated area within the plane angle of 90° (it corresponds to 0.146 of 4p). Under such geometry, the dependence of the count rate for excited characteristic photons on the position of sample under study has a smooth maximum in the calculated sample position point. For one, the rate count changes by less than 1%. Quantitative results are obtained through the regression method. The instrument underwent metrology testing. It is designed for operation both in the laboratory and industrial environment. The instrument has been delivered for operation to the "Druzhba" pipeline.

  15. Accretion, fluorescent X-ray emission and flaring magnetic structures in YSOs

    E-print Network

    F. Favata

    2004-12-20

    I present some recent developments on high-energy phenomena in YSOs, concentrating on the new evidence for accretion-induced X-ray emission in YSOs, for Fe 6.4 keV fluorescent emission from the disks of YSOs and for very long magnetic structures responsible for intense X-ray flares, likely connecting the star and the circumstellar disk.

  16. RADIOCHEMICAL ANALYSIS BY HIGH SENSITIVITY DUAL-OPTIC MICRO X-RAY FLUORESCENCE

    EPA Science Inventory

    A novel dual-optic micro X-ray fluorescence instrument will be developed to do radiochemical analysis of high-level radioactive wastes at DOE sites such as Savannah River Site and Hanford. This concept incorporates new X-ray optical elements such as monolithic polycapillaries and...

  17. Application of a charge-coupled device photon-counting technique to three-dimensional element analysis of a plant seed (alfalfa) using a full-field x-ray fluorescence imaging microscope

    SciTech Connect

    Hoshino, Masato; Ishino, Toyoaki; Namiki, Takashi; Yamada, Norimitsu; Watanabe, Norio; Aoki, Sadao [Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8571 (Japan)

    2007-07-15

    A full-field x-ray fluorescence imaging microscope using a Wolter mirror was constructed at Photon Factory BL3C2. White x rays from a bending magnet were used to excite x-ray fluorescence and to enhance the x-ray fluorescence intensity. A photon-counting method using a charge-coupled device was applied to obtain an x-ray fluorescence spectrum at the image plane. The spatial distributions of some specific atoms such as Fe and Zn were obtained from photon-counting calculations. An energy resolution of 220 eV at the Fe K{alpha} line was obtained from the x-ray fluorescence spectrum by the photon-counting method. The newly developed three-dimensional element mappings of the specific atoms were accomplished by the photon-counting method and a reconstruction technique using computed tomography.

  18. Development of a Planetary X-Ray Fluorescence Spectrometer and Standard Samples for on-board Calibration

    NASA Astrophysics Data System (ADS)

    Dreißigacker, A.; Fabel, O.; Köhler, E.; van Gasselt, S.; Meyer, M.

    2014-04-01

    At the Planetary Sciences and Remote Sensing research group at Freie Universität Berlin an SCDbased X-Ray Fluorescence Spectrometer (XRF-X) is being developed to be employed on planetary orbiters. It performs direct, passive energy-dispersive X-ray fluorescence measurements of planetary surfaces by measuring the emitted X-ray fluorescence induced by solar X-rays and high-energy particles.

  19. Forensic application of total reflection X-ray fluorescence spectrometry for elemental characterization of ink samples

    NASA Astrophysics Data System (ADS)

    Dhara, Sangita; Misra, N. L.; Maind, S. D.; Kumar, Sanjukta A.; Chattopadhyay, N.; Aggarwal, S. K.

    2010-02-01

    The possibility of applying Total Reflection X-ray Fluorescence for qualitative and quantitative differentiation of documents printed with rare earth tagged and untagged inks has been explored in this paper. For qualitative differentiation, a very small amount of ink was loosened from the printed documents by smoothly rubbing with a new clean blade without destroying the manuscript. 50 ?L of Milli-Q water was put on this loose powder, on the manuscript, and was agitated by sucking and releasing the suspension two to three times with the help of a micropipette. The resultant dispersion was deposited on quartz sample support for Total Reflection X-ray Fluorescence measurements. The Total Reflection X-ray Fluorescence spectrum of tagged and untagged inks could be clearly differentiated. In order to see the applicability of Total Reflection X-ray Fluorescence for quantitative determinations of rare earths and also to countercheck such determinations in ink samples, the amounts of rare earth in painted papers with single rare earth tagged inks were determined by digesting the painted paper in HNO 3/HClO 4, mixing this solution with the internal standard and recording their Total Reflection X-ray Fluorescence spectra after calibration of the instrument. The results thus obtained were compared with those obtained by Inductively Coupled Plasma Mass Spectrometry and were found in good agreement. The average precision of the Total Reflection X-ray Fluorescence determinations was 5.5% (1 ?) and the average deviation of Total Reflection X-ray Fluorescence determined values with that of Inductively Coupled Plasma Mass Spectrometry was 7.3%. These studies have shown that Total Reflection X-ray Fluorescence offers a promising and potential application in forensic work of this nature.

  20. PHYSICAL REVIEW B 87, 064111 (2013) Element sensitive holographic imaging of atomic structures using white x rays

    E-print Network

    Korecki, Pawe³

    2013-01-01

    using white x rays K. M. D abrowski, D. T. Dul, T. P. Roszczynialski, and P. Korecki* Institute 28 February 2013) White-beam x-ray fluorescence holograms were recorded using a 50 watt x-ray tube by measuring distinct holograms using Cu K and Au L x-ray fluorescence. The phase sensitivity of the recorded

  1. Laboratory-based micro-X-ray fluorescence setup using a von Hamos crystal spectrometer and a focused beam X-ray tube

    NASA Astrophysics Data System (ADS)

    Kayser, Y.; B?achucki, W.; Dousse, J.-Cl.; Hoszowska, J.; Neff, M.; Romano, V.

    2014-04-01

    The high-resolution von Hamos bent crystal spectrometer of the University of Fribourg was upgraded with a focused X-ray beam source with the aim of performing micro-sized X-ray fluorescence (XRF) measurements in the laboratory. The focused X-ray beam source integrates a collimating optics mounted on a low-power micro-spot X-ray tube and a focusing polycapillary half-lens placed in front of the sample. The performances of the setup were probed in terms of spatial and energy resolution. In particular, the fluorescence intensity and energy resolution of the von Hamos spectrometer equipped with the novel micro-focused X-ray source and a standard high-power water-cooled X-ray tube were compared. The XRF analysis capability of the new setup was assessed by measuring the dopant distribution within the core of Er-doped SiO2 optical fibers.

  2. New Atomicity-Exploiting Algorithms for Super-Resolution X-Ray Crystallography

    E-print Network

    Yagle, Andrew E.

    1 New Atomicity-Exploiting Algorithms for Super-Resolution X-Ray Crystallography Andrew E. Yagle Department of EECS, The University of Michigan, Ann Arbor, MI 48109-2122 Abstract-- The X-ray crystallography the algorithms. Keywords-- X-ray crystallography, sparse images. Phone: 734-763-9810. Fax: 734-763-1503. Email

  3. Dual-modality molecular imaging for small animals using fluorescence and x-ray computed tomography

    NASA Astrophysics Data System (ADS)

    Lin, Yuting; Barber, William C.; Iwanczyk, Jan S.; Nygard, Einar; Malakov, Nail; Hartsough, Neal E.; Gandhi, Thulasi; Roeck, Werner W.; Nalcioglu, Orhan; Gulsen, Gultekin

    2009-07-01

    We demonstrate the feasibility of using a dual-modality fluorescence and x-ray computed tomography (CT) system for quantitative molecular imaging with phantom studies. A CCD based non-contact FT system, which can take measurements from multiple views was built. High-resolution X-Ray CT was used to obtain structural information from the phantom. A 3.6 mm diameter fluorescence inclusion was deeply embedded in the heterogeneous optical background. The results demonstrated that the fluorophore concentration can only be obtained accurately when guided by the a priori information provided by the x-ray CT.

  4. New approach to breast tumor detection based on fluorescence x-ray analysis

    PubMed Central

    Hayashi, Yasuhiko; Okuyama, Fumio

    2010-01-01

    A new technical approach to breast-tumor detection is proposed. The technique is based on fluorescence x-ray analysis, and can identify a miniature malignant tumor within the breast. The primary beam intensity needed in fluorescence x-ray analysis is on a lower order of magnitude than that used in mammography. Thus, the newly-proposed technique would enable detection of a still tiny breast cancer while dramatically lowering the radiation dose. Field-emission x-ray sources might be a key for translating this concept into a medical technique. PMID:20930932

  5. Multiplexed biomarker detection using x-ray fluorescence of composition-encoded nanoparticles

    SciTech Connect

    Hossain, Mainul; Wang Chaoming; Su Ming [NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826 (United States); School of Electrical Engineering and Computer Science, University of Central Florida, Orlando, Florida 32826 (United States)

    2010-12-27

    Multiple DNA and protein biomarkers have been detected based on characteristic x-ray fluorescence of a panel of metal and alloy nanoparticles, which are modified with ligands of biomarkers to create a one-to-one correspondence and immobilized on ligand-modified substrates after forming complexes with target biomarkers in three-strand or sandwich configuration. By determining the presence and concentration of nanoparticles using x-ray fluorescence, the nature and amount of biomarkers can be detected with limits of 1 nM for DNA and 1 ng/ml for protein. By combining high penetrating ability of x-rays, this method allows quantitative imaging of multiple biomarkers.

  6. Method for detecting binding events using micro-X-ray fluorescence spectrometry

    DOEpatents

    Warner, Benjamin P. (Los Alamos, NM); Havrilla, George J. (Los Alamos, NM); Mann, Grace (Hong Kong, HK)

    2010-12-28

    Method for detecting binding events using micro-X-ray fluorescence spectrometry. Receptors are exposed to at least one potential binder and arrayed on a substrate support. Each member of the array is exposed to X-ray radiation. The magnitude of a detectable X-ray fluorescence signal for at least one element can be used to determine whether a binding event between a binder and a receptor has occurred, and can provide information related to the extent of binding between the binder and receptor.

  7. X-ray absorption spectroscopy: A fluorescence detection system based on a plastic scintillator

    NASA Astrophysics Data System (ADS)

    Tourillon, G.; Guay, D.; Lemonnier, M.; Bartol, F.; Badeyan, M.

    1990-09-01

    A fluorescence detection system based on a plastic scintillator is presented that can be used for both X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine-structure (EXAFS) spectroscopy. Its counting rate is limited by the pulsation frequency of the synchrotron radiation (3.16×10 6 counts s -1), and can be theoretically extended to roughly 5×10 7 counts s -1 if used on a multibunch storage ring synchrotron radiation source. Its physical characteristics (fluorescence decay time and fast electronics) are such that the dead-time correction is entirely defined by the revolution period of the charged particles in the storage ring. It shows a broad spectral response and is particularly well adapted to the measurement of hard X-rays (from 6 to 25 keV). Its volume is small (diameter 60 mm; height 240 mm), and filters of small dimensions are used to preferentially remove the scattered radiation. The entrance window of the detector is placed at 2-3 mm above the top of the sample, and a solid angle of collection of nearly 50% of 2? sr is achieved. The shape of the plastic scintillator can be easily modified to fit various geometries. It operates in both horizontal and vertical planes. It is about ten times less expensive than an energy-dispersive detection system based on a single Ge solid-state detector. The detector presents a high sensitivity. It is possible to obtain the entire EXAFS spectrum of an electrochemically (under potential deposition) deposited monolayer of Cu atoms on gold, with acquisition time of less than one hour (compared to 25 h for a Ge solid-state detector). Orientation-dependent X-ray absorption spectroscopy was performed on thin (800 Å) copper phthalocyanine film, and the spectra of diluted Cu 2+ ions in aqueous solution (18 ppm) and Co atoms in YBa 2Cu 3O 7 powder (230 ppm) were also measured to assess the sensitivity of the detector.

  8. Determination of L X-ray fluorescence parameters for Ho, Lu, W, Hg and Bi.

    PubMed

    Turhan, M F; Durak, R; Akman, F

    2014-07-01

    In this work, L X-ray fluorescence cross sections, L sub-shell fluorescence yields and level widths and radiative vacancy transfer probabilities of L sub-shells to Mi, Ni and Oi sub-shells were measured for the elements Ho, Lu, W, Hg and Bi. Energy dispersive X-ray fluorescence (EDXRF) technique was used to measure L X-ray photons. To obtain related parameters, we used 59.54 keV gamma photons of (241)Am radioactive point source. Emitted L X-ray photons from targets were collected by means of a Si(Li) detector with resolution of 180 eV at 5.9 keV. The present results are generally in a good agreement with theoretical calculations and the other results obtained in the literature, within their range considering experimental uncertainty. PMID:24631748

  9. Estimation of grain size variability with micro X-ray fluorescence in laminated lacustrine sediments, Cape Bounty, Canadian High Arctic

    Microsoft Academic Search

    Stéphanie Cuven; Pierre Francus; Scott F. Lamoureux

    2010-01-01

    Finely laminated sediment cores from two Arctic lakes were investigated using the Itrax™ Core Scanner that provides micro\\u000a X-ray fluorescence (?-XRF) measurements with a spatial resolution of 100 ?m. We compared these chemical measurements with\\u000a standard geochemical methods using, at the macroscopic scale, inductively coupled plasma–atomic emission spectrometry (ICP-AES)\\u000a and, at the microscopic scale, energy dispersive spectroscopy (EDS). We also investigated

  10. Optimized Detector Angular Configuration Increases the Sensitivity of X-ray Fluorescence Computed Tomography (XFCT).

    PubMed

    Ahmad, Moiz; Bazalova-Carter, Magdalena; Fahrig, Rebecca; Xing, Lei

    2015-05-01

    In this work, we demonstrated that an optimized detector angular configuration based on the anisotropic energy distribution of background scattered X-rays improves X-ray fluorescence computed tomography (XFCT) detection sensitivity. We built an XFCT imaging system composed of a bench-top fluoroscopy X-ray source, a CdTe X-ray detector, and a phantom motion stage. We imaged a 6.4-cm-diameter phantom containing different concentrations of gold solution and investigated the effect of detector angular configuration on XFCT image quality. Based on our previous theoretical study, three detector angles were considered. The X-ray fluorescence detector was first placed at 145 (°) (approximating back-scatter) to minimize scatter X-rays. XFCT image quality was compared to images acquired with the detector at 60 (°) (forward-scatter) and 90 (°) (side-scatter). The datasets for the three different detector positions were also combined to approximate an isotropically arranged detector. The sensitivity was optimized with detector in the 145 (°) back-scatter configuration counting the 78-keV gold K?1 X-rays. The improvement arose from the reduced energy of scattered X-ray at the 145 (°) position and the large energy separation from gold K ?1 X-rays. The lowest detected concentration in this configuration was 2.5 mgAu/mL (or 0.25% Au with SNR = 4.3). This concentration could not be detected with the 60 (°) , 90 (°) , or isotropic configurations (SNRs = 1.3, 0, 2.3, respectively). XFCT imaging dose of 14 mGy was in the range of typical clinical X-ray CT imaging doses. To our knowledge, the sensitivity achieved in this experiment is the highest in any XFCT experiment using an ordinary bench-top X-ray source in a phantom larger than a mouse ( > 3 cm). PMID:25474808

  11. A method for forward energy-dispersive X-ray fluorescence analysis of thin and intermediate samples

    NASA Astrophysics Data System (ADS)

    Cesareo, Roberto; Gigante, Giovanni E.; Hanson, Albert L.

    1998-11-01

    The usefulness of forward geometry in Energy Dispersive X-Ray Fluorescence (EDXRF) analysis has been investigated both experimentally and theoretically. This work relates to milli- and micro-beams, which limits this work to tightly collimated incident X-ray beams (<1 mm). The use of forward geometry also limits the targets to be of thin and intermediate thickness. The advantages and the peculiarities of using a forward geometry for XRF are discussed. Forward X-Ray Fluorescence (FXRF) has features including: (a) high geometrical efficiencies when using tightly collimated primary beams; (b) a minimisation in the uncertainty in the interaction volume; (c) a sample thickness at which the production of characteristic X rays is maximised; and (d) a filtering action by intermediate thickness samples resulting in an enhancement of the sensitivity for higher atomic number elements with respect to lower atomic number elements. For thin and intermediate thickness samples simultaneous forward and backward geometry XRF can be used to correct for self-absorption effect.

  12. Case Studies on Facility Characterization with X-Ray Fluorescence Spectrometry

    SciTech Connect

    Kirk, K.T.; Brooksbank, R.D.; Meszaros, J.M.; Towery, W.E. [Bechtel Jacobs Company LLC: P.O. Box 4699, Oak Ridge, Tennessee, 37831-7405 (United States)

    2008-01-15

    A hand-held x-ray fluorescence (XRF) analyzer is being used to characterize facilities in support of demolition activities at the East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee. Approximately 500 facilities at the U.S. Department of Energy site are being demolished under the ETTP Decontamination and Decommissioning (D and D) project. Facility characterization is being conducted to provide data for waste profiling and identify hazards to demolition workers. XRF spectrometry is a non-destructive analytical technique used to identify and quantify the elemental composition of a substance based on the intensity of its characteristic X-ray emission wavelength or energy. The Innov-X Systems{sup R} Model XT-245S XRF analyzer used at ETTP is equipped with a silver anode x-ray tube and a Si PIN diode detector. X-rays are generated by electrical current, eliminating the need for radioactive isotopes. Electronic components can be powered by either a lithium-ion battery or an A/C adapter, and the instrument is controlled by an iPAQ{sup R} pocket personal computer. The unit has two primary operating modes. Alloy analysis mode measures percent levels of elements in metals such as a pipes, valves, equipment, or construction materials. Soil mode provides parts-per-million (ppm) quantities in bulk solids like concrete dust, residue, paint chips, or soil. The hand-held unit can analyze material in place, or it can analyze samples in a test stand by remote operation. This paper present some case studies demonstrating a variety of XRF applications for facility characterization: Metal Materials Characterization, Lead Paint Identification, Hot Spot Delineation, Bulk Solids Testing. XRF has been the analytical technique of choice for identifying metal alloy components and has also been useful in analyzing bulk materials. Limitations of XRF testing include the inability to directly analyze elements with low atomic weights. Light elements such as beryllium and aluminum do not emit characteristic x-rays that the instrument can detect. However, process knowledge and existing historical data can be used to evaluate the presence of beryllium, which has been widely characterized at ETTP using industrial hygiene smear samples. Aluminum can be indirectly measured in aluminum alloys using x-ray scatter lines. The Innov-X Systems XRF has a light elements setting that employs this method, and it has been widely used on the ETTP D and D project. Another potential limitation involves analyzing samples that are radioactive, or analyzing samples in a radioactive environment. Radiation (including gamma, beta, and high energy alpha particles) acts as another excitation mechanism to create x-rays from materials being analyzed. Samples analyzed under those conditions will absorb more x-rays than just those emitted by the instrument silver anode tube, resulting in a potential high bias. This type of interference is identified by radiological surveys and minimized by relocating measurements to areas of lower activity when feasible.

  13. Combined evaluation of grazing incidence X-ray fluorescence and X-ray reflectivity data for improved profiling of ultra-shallow depth distributions.

    PubMed

    Ingerle, D; Meirer, F; Pepponi, G; Demenev, E; Giubertoni, D; Wobrauschek, P; Streli, C

    2014-09-01

    The continuous downscaling of the process size for semiconductor devices pushes the junction depths and consequentially the implantation depths to the top few nanometers of the Si substrate. This motivates the need for sensitive methods capable of analyzing dopant distribution, total dose and possible impurities. X-ray techniques utilizing the external reflection of X-rays are very surface sensitive, hence providing a non-destructive tool for process analysis and control. X-ray reflectometry (XRR) is an established technique for the characterization of single- and multi-layered thin film structures with layer thicknesses in the nanometer range. XRR spectra are acquired by varying the incident angle in the grazing incidence regime while measuring the specular reflected X-ray beam. The shape of the resulting angle-dependent curve is correlated to changes of the electron density in the sample, but does not provide direct information on the presence or distribution of chemical elements in the sample. Grazing Incidence XRF (GIXRF) measures the X-ray fluorescence induced by an X-ray beam incident under grazing angles. The resulting angle dependent intensity curves are correlated to the depth distribution and mass density of the elements in the sample. GIXRF provides information on contaminations, total implanted dose and to some extent on the depth of the dopant distribution, but is ambiguous with regard to the exact distribution function. Both techniques use similar measurement procedures and data evaluation strategies, i.e. optimization of a sample model by fitting measured and calculated angle curves. Moreover, the applied sample models can be derived from the same physical properties, like atomic scattering/form factors and elemental concentrations; a simultaneous analysis is therefore a straightforward approach. This combined analysis in turn reduces the uncertainties of the individual techniques, allowing a determination of dose and depth profile of the implanted elements with drastically increased confidence level. Silicon wafers implanted with Arsenic at different implantation energies were measured by XRR and GIXRF using a combined, simultaneous measurement and data evaluation procedure. The data were processed using a self-developed software package (JGIXA), designed for simultaneous fitting of GIXRF and XRR data. The results were compared with depth profiles obtained by Secondary Ion Mass Spectrometry (SIMS). PMID:25202165

  14. Combined evaluation of grazing incidence X-ray fluorescence and X-ray reflectivity data for improved profiling of ultra-shallow depth distributions?

    PubMed Central

    Ingerle, D.; Meirer, F.; Pepponi, G.; Demenev, E.; Giubertoni, D.; Wobrauschek, P.; Streli, C.

    2014-01-01

    The continuous downscaling of the process size for semiconductor devices pushes the junction depths and consequentially the implantation depths to the top few nanometers of the Si substrate. This motivates the need for sensitive methods capable of analyzing dopant distribution, total dose and possible impurities. X-ray techniques utilizing the external reflection of X-rays are very surface sensitive, hence providing a non-destructive tool for process analysis and control. X-ray reflectometry (XRR) is an established technique for the characterization of single- and multi-layered thin film structures with layer thicknesses in the nanometer range. XRR spectra are acquired by varying the incident angle in the grazing incidence regime while measuring the specular reflected X-ray beam. The shape of the resulting angle-dependent curve is correlated to changes of the electron density in the sample, but does not provide direct information on the presence or distribution of chemical elements in the sample. Grazing Incidence XRF (GIXRF) measures the X-ray fluorescence induced by an X-ray beam incident under grazing angles. The resulting angle dependent intensity curves are correlated to the depth distribution and mass density of the elements in the sample. GIXRF provides information on contaminations, total implanted dose and to some extent on the depth of the dopant distribution, but is ambiguous with regard to the exact distribution function. Both techniques use similar measurement procedures and data evaluation strategies, i.e. optimization of a sample model by fitting measured and calculated angle curves. Moreover, the applied sample models can be derived from the same physical properties, like atomic scattering/form factors and elemental concentrations; a simultaneous analysis is therefore a straightforward approach. This combined analysis in turn reduces the uncertainties of the individual techniques, allowing a determination of dose and depth profile of the implanted elements with drastically increased confidence level. Silicon wafers implanted with Arsenic at different implantation energies were measured by XRR and GIXRF using a combined, simultaneous measurement and data evaluation procedure. The data were processed using a self-developed software package (JGIXA), designed for simultaneous fitting of GIXRF and XRR data. The results were compared with depth profiles obtained by Secondary Ion Mass Spectrometry (SIMS). PMID:25202165

  15. X-ray beam induced current\\/microprobe x-ray fluorescence: synchrotron radiation based x-ray microprobe techniques for analysis of the recombination activity and chemical nature of metal impurities in silicon

    Microsoft Academic Search

    O F Vyvenko; T Buonassisi; A A Istratov; E R Weber

    2004-01-01

    In this study we report applications of the synchrotron radiation based x-ray microprobe techniques, x-ray beam induced current (XBIC) and microprobe x-ray fluorescence (?-XRF), to the analysis of the recombination activity and spatial distribution of transition metals in silicon. A combination of these two techniques enables one to study the elemental nature of defects and impurities and their recombination activity

  16. An X-ray refractive lens comprising two sections cut from a gramophone record for a portable total reflection X-ray fluorescence spectrometer

    NASA Astrophysics Data System (ADS)

    Kunimura, Shinsuke; Kawai, Jun

    2009-08-01

    An X-ray refractive lens is assembled from two sections cut from a gramophone record. The refractive lens is placed in a portable total reflection X-ray fluorescence (TXRF) spectrometer, and it is used for collimation of the incident X-ray beams. A TXRF spectrum measured with the refractive lens is compared with that measured with a waveguide. Compared with the refractive lens, the waveguide enhances the intensities of the X-rays illuminating an analyte. Therefore, fluorescent X-ray intensities increase when using the waveguide. On the other hand, the vertical angular divergence of the incident X-ray beams is smaller when using the refractive lens, and the smaller angular divergence results in a reduction of the scattering of the incident X-rays from a sample holder. Therefore, the spectral background is reduced when using the refractive lens, resulting in an increase of the signal to background ratios of the fluorescent X-rays. Detection limits for 3d transition metals obtained with the refractive lens are sub-nanograms to a few nanograms, and the detection limits are similar to those obtained with the waveguide.

  17. Measurements of Multiphase Fluid Mixing Using Synchrotron X-Ray Fluorescence

    NASA Astrophysics Data System (ADS)

    Kastengren, Alan; Halls, Benjamin; Meyer, Terry

    2013-11-01

    Multiphase flows can prove problematic for the use of optical diagnostics due to the strong interaction of visible light with phase boundaries. X-ray absorption and phase-contrast imaging have been successfully used to probe multiphase fluid flows under a wide variety of conditions. This presentation will describe the use of another technique, x-ray fluorescence spectroscopy, to probe an impinging jet spray flowfield. The x-ray fluorescence technique will be described, including its advantages and drawbacks compared to other techniques, both optical and x-ray. Preliminary results from the impinging jet flowfield show that the fluid from each initial jet tends to congregate on the side of the sheet formed after the impingement point opposite the jet. This behavior was not expected prior to these measurements, demonstrating the utility of the fluorescence technique to probe the mixing of the two streams. Other potential applications for the x-ray fluorescence technique will also be briefly discussed. Multiphase flows can prove problematic for the use of optical diagnostics due to the strong interaction of visible light with phase boundaries. X-ray absorption and phase-contrast imaging have been successfully used to probe multiphase fluid flows under a wide variety of conditions. This presentation will describe the use of another technique, x-ray fluorescence spectroscopy, to probe an impinging jet spray flowfield. The x-ray fluorescence technique will be described, including its advantages and drawbacks compared to other techniques, both optical and x-ray. Preliminary results from the impinging jet flowfield show that the fluid from each initial jet tends to congregate on the side of the sheet formed after the impingement point opposite the jet. This behavior was not expected prior to these measurements, demonstrating the utility of the fluorescence technique to probe the mixing of the two streams. Other potential applications for the x-ray fluorescence technique will also be briefly discussed. Use of the Advanced Photon Source, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357.

  18. A Comprehensive X-Ray Absorption Model for Atomic Oxygen

    NASA Technical Reports Server (NTRS)

    Gorczyca, T. W.; Bautista, M. A.; Hasoglu, M. F.; Garcia, J.; Gatuzz, E.; Kaastra, J. S.; Kallman, T. R.; Manson, S. T.; Mendoza, C.; Raassen, A. J. J.; de Vries, C. P.; Zatsarinny, O.

    2013-01-01

    An analytical formula is developed to accurately represent the photoabsorption cross section of atomic Oxygen for all energies of interest in X-ray spectral modeling. In the vicinity of the K edge, a Rydberg series expression is used to fit R-matrix results, including important orbital relaxation effects, that accurately predict the absorption oscillator strengths below threshold and merge consistently and continuously to the above-threshold cross section. Further, minor adjustments are made to the threshold energies in order to reliably align the atomic Rydberg resonances after consideration of both experimental and observed line positions. At energies far below or above the K-edge region, the formulation is based on both outer- and inner-shell direct photoionization, including significant shake-up and shake-off processes that result in photoionization-excitation and double-photoionization contributions to the total cross section. The ultimate purpose for developing a definitive model for oxygen absorption is to resolve standing discrepancies between the astronomically observed and laboratory-measured line positions, and between the inferred atomic and molecular oxygen abundances in the interstellar medium from XSTAR and SPEX spectral models.

  19. Cryo X-ray microscope with flat sample geometry for correlative fluorescence and nanoscale tomographic imaging.

    PubMed

    Schneider, Gerd; Guttmann, Peter; Rehbein, Stefan; Werner, Stephan; Follath, Rolf

    2012-02-01

    X-ray imaging offers a new 3-D view into cells. With its ability to penetrate whole hydrated cells it is ideally suited for pairing fluorescence light microscopy and nanoscale X-ray tomography. In this paper, we describe the X-ray optical set-up and the design of the cryo full-field transmission X-ray microscope (TXM) at the electron storage ring BESSY II. Compared to previous TXM set-ups with zone plate condenser monochromator, the new X-ray optical layout employs an undulator source, a spherical grating monochromator and an elliptically shaped glass capillary mirror as condenser. This set-up improves the spectral resolution by an order of magnitude. Furthermore, the partially coherent object illumination improves the contrast transfer of the microscope compared to incoherent conditions. With the new TXM, cells grown on flat support grids can be tilted perpendicular to the optical axis without any geometrical restrictions by the previously required pinhole for the zone plate monochromator close to the sample plane. We also developed an incorporated fluorescence light microscope which permits to record fluorescence, bright field and DIC images of cryogenic cells inside the TXM. For TXM tomography, imaging with multi-keV X-rays is a straightforward approach to increase the depth of focus. Under these conditions phase contrast imaging is necessary. For soft X-rays with shrinking depth of focus towards 10nm spatial resolution, thin optical sections through a thick specimen might be obtained by deconvolution X-ray microscopy. As alternative 3-D X-ray imaging techniques, the confocal cryo-STXM and the dual beam cryo-FIB/STXM with photoelectron detection are proposed. PMID:22273540

  20. Americium characterization by X-ray fluorescence and absorption spectroscopy in plutonium uranium mixed oxide

    SciTech Connect

    Degueldre, Claude, E-mail: claude.degueldre@psi.ch; Cozzo, Cedric; Martin, Matthias; Grolimund, Daniel; Mieszczynski, Cyprian

    2013-06-01

    Plutonium uranium mixed oxide (MOX) fuels are currently used in nuclear reactors. The actinides in these fuels need to be analyzed after irradiation for assessing their behaviour with regard to their environment and the coolant. In this work the study of the atomic structure and next-neighbour environment of Am in the (Pu,U)O? lattice in an irradiated (60 MW d kg?¹) MOX sample was performed employing micro-X-ray fluorescence (µ-XRF) and micro-X-ray absorption fine structure (µ-XAFS) spectroscopy. The chemical bonds, valences and stoichiometry of Am (~0.66 wt%) are determined from the experimental data gained for the irradiated fuel material examined in its peripheral zone (rim) of the fuel. In the irradiated sample Am builds up as Am³? species within an [AmO?]¹³? coordination environment (e.g. >90%) and no (<10%) Am(IV) or (V) can be detected in the rim zone. The occurrence of americium dioxide is avoided by the redox buffering activity of the uranium dioxide matrix. - Graphical abstract: Americium LIII XAFS spectra recorded for the irradiated MOX sub-sample in the rim zone for a 300 ?m×300 ?m beam size area investigated over six scans of 4 h. The records remain constant during multi-scan. The analysis of the XAFS signal shows that Am is found as trivalent in the UO? matrix. This analytical work shall open the door of very challenging analysis (speciation of fission product and actinides) in irradiated nuclear fuels. - Highlights: • Americium was characterized by microX-ray absorption spectroscopy in irradiated MOX fuel. • The americium redox state as determined from XAS data of irradiated fuel material was Am(III). • In the sample, the Am³? face an AmO?¹³?coordination environment in the (Pu,U)O? matrix. • The americium dioxide is reduced by the uranium dioxide matrix.

  1. Americium characterization by X-ray fluorescence and absorption spectroscopy in plutonium uranium mixed oxide

    NASA Astrophysics Data System (ADS)

    Degueldre, Claude; Cozzo, Cedric; Martin, Matthias; Grolimund, Daniel; Mieszczynski, Cyprian

    2013-06-01

    Plutonium uranium mixed oxide (MOX) fuels are currently used in nuclear reactors. The actinides in these fuels need to be analyzed after irradiation for assessing their behaviour with regard to their environment and the coolant. In this work the study of the atomic structure and next-neighbour environment of Am in the (Pu,U)O2 lattice in an irradiated (60 MW d kg-1) MOX sample was performed employing micro-X-ray fluorescence (µ-XRF) and micro-X-ray absorption fine structure (µ-XAFS) spectroscopy. The chemical bonds, valences and stoichiometry of Am (˜0.66 wt%) are determined from the experimental data gained for the irradiated fuel material examined in its peripheral zone (rim) of the fuel. In the irradiated sample Am builds up as Am3+ species within an [AmO8]13- coordination environment (e.g. >90%) and no (<10%) Am(IV) or (V) can be detected in the rim zone. The occurrence of americium dioxide is avoided by the redox buffering activity of the uranium dioxide matrix.

  2. BRUKER ADVANCED X-RAY SOLUTIONS TOTAL REFLECTION X-RAY FLUORESCENCE

    E-print Network

    Wells, Mathew G. - Department of Physical and Environmental Sciences, University of Toronto

    ) and the intensity is measured by means of an amplifier coupled to a multi- channel analyzer. The main difference of TXRF, compared to atomic spectroscopy methods like AAS or ICP- OES, is the avoidance of memory effects

  3. High Resolution X-ray FluorescenceScanning Microscopy Project Description

    E-print Network

    Cinabro, David

    High Resolution X-ray FluorescenceScanning Microscopy Project Description The project requires fluorescent radiation given off by the target sample. The radiation is then detected, and a spectrum some minor data analysis,and displayed a few simple data scan spectrum in graphic form. Graph 1 ~ Graph

  4. Hybrid System for Simultaneous Fluorescence and X-Ray Computed Tomography

    Microsoft Academic Search

    Ralf B. Schulz; Angelique Ale; Athanasios Sarantopoulos; Marcus Freyer; Eric Soehngen; Marta Zientkowska; Vasilis Ntziachristos

    2010-01-01

    A hybrid imaging system for simultaneous fluorescence tomography and X-ray computed tomography (XCT) of small animals has been developed and presented. The system capitalizes on the imaging power of a 360 ??-projection free-space fluorescence tomography system, implemented within a microcomputed tomography scanner. Image acquisition is based on techniques that automatically adjust a series of imaging parameters to offer a high

  5. Bridging the micro-to-macro gap: a new application for micro X-ray fluorescence.

    PubMed

    Davis, Jeffrey M; Newbury, Dale E; Fahey, Albert; Ritchie, Nicholas W M; Vicenzi, Edward; Bentz, Dale

    2011-06-01

    X-ray elemental mapping and X-ray spectrum imaging are powerful microanalytical tools. However, their scope is often limited spatially by the raster area of a scanning electron microscope or microprobe. Limited sampling size becomes a significant issue when large area (>10 cm²), heterogeneous materials such as concrete samples or others must be examined. In such specimens, macro-scale structures, inclusions, and concentration gradients are often of interest, yet microbeam methods are insufficient or at least inefficient for analyzing them. Such requirements largely exclude the samples of interest presented in this article from electron probe microanalysis. Micro X-ray fluorescence-X-ray spectrum imaging (?XRF-XSI) provides a solution to the problem of macro-scale X-ray imaging through an X-ray excitation source, which can be used to analyze a variety of large specimens without many of the limitations found in electron-excitation sources. Using a mid-sized beam coupled with an X-ray excitation source has a number of advantages, such as the ability to work at atmospheric pressure and lower limits of detection owing to the absence of electron-induced bremsstrahlung. ?XRF-XSI also acts as a complement, where applicable, to electron microbeam X-ray output, highlighting areas of interest for follow-up microanalysis at a finer length scale. PMID:21600071

  6. Resonant excitation x-ray fluorescence from C{sub 60}

    SciTech Connect

    Guo, J.; Glans, P.; Skytt, P.; Wassdahl, N.; Nordgren, J. [Department of Physics, Uppsala University, Box 530, S-751 21 Uppsala (Sweden)] [Department of Physics, Uppsala University, Box 530, S-751 21 Uppsala (Sweden); Luo, Y.; Agren, H. [Department of Physics and Measurement Technology, Linkoeping University, S-581 83 Linkoeping (Sweden)] [Department of Physics and Measurement Technology, Linkoeping University, S-581 83 Linkoeping (Sweden); Ma, Y. [Physics Department, University of Washington, Seattle, Washington 98195 (United States)] [Physics Department, University of Washington, Seattle, Washington 98195 (United States); [Molecular Science Research Center, Pacific Northwest Laboratories, Richland, Washington 99352 (United States); Warwick, T.; Heimann, P. [Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States)] [Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States); Rotenberg, E. [Department of Physics, University of Oregon, Eugene, Oregon 97403 (United States)] [Department of Physics, University of Oregon, Eugene, Oregon 97403 (United States); Denlinger, J.D. [Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211 (United States)] [Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211 (United States)

    1995-10-15

    X-ray fluorescence of condensed C{sub 60} has been recorded in high resolution using monochromatic synchrotron radiation excitation. Strong intensity modulation of constituent spectral features is observed with varying excitation energy up to 10 eV above threshold. The energy dependence is interpreted as due to resonant inelastic x-ray scattering, leading to symmetry selection rules governing the two-photon process in the fully symmetric molecule.

  7. In Vivo X-Ray Fluorescence Microtomographic Imaging of Elements in Single-Celled Fern Spores

    Microsoft Academic Search

    Yasuharu Hirai; Akio Yoneyama; Akiko Hisada; Kenko Uchida

    2007-01-01

    We have observed in vivo three-dimensional distributions of constituent elements of single-celled spores of the fern Adiantum capillus-veneris using an X-ray fluorescence computed microtomography method. The images of these distributions are generated from a series of slice data, each of which is acquired by a sample translation-rotation method. An incident X-ray microbeam irradiates the sample with a spot size of

  8. Development of Ta-based Superconducting Tunnel Junction X-ray Detectors for Fluorescence XAS

    Microsoft Academic Search

    Stephan Friedrich; Owen B. Drury; John Hall; Robin Cantor

    2010-01-01

    We are developing superconducting tunnel junction (STJ) soft X-ray detectors for chemical analysis of dilute samples by fluorescence-detected X-ray absorption spectroscopy (XAS). Our 36-pixel Nb-based STJ spectrometer covers a solid angle Omega\\/4pi~10-3, offers an energy resolution of ~10-20 eV FWHM for energies up to ~1 keV, and can be operated at total count rates of ~106 counts\\/s. For increased quantum

  9. Development of Ta-based Superconducting Tunnel Junction X-ray Detectors for Fluorescence XAS

    Microsoft Academic Search

    S Friedrich; O Drury; J Hall; R Cantor

    2009-01-01

    We are developing superconducting tunnel junction (STJ) soft X-ray detectors for chemical analysis of dilute samples by fluorescence-detected X-ray absorption spectroscopy (XAS). Our 36-pixel Nb-based STJ spectrometer covers a solid angle \\/4 10³, offers an energy resolution of 10-20 eV FWHM for energies up to 1 keV, and can be operated at total count rates of 10 counts\\/s. For increased

  10. X-ray Atomic-Scale Analysis of Self-Assembled Monolayer Growth on Silicon

    NASA Astrophysics Data System (ADS)

    Lin, J. C.; Kellar, J.; Kim, J.; Yoder, N.; Bevan, K.; Datta, S.; Nguyen, S.; Hersam, M.; Bedzyk, M.

    2008-03-01

    Organic functionalization of silicon is of interest for applications ranging from biosensing to molecular electronics. The efficiency of molecular devices heavily depends on the ordering of the structure. Traditionally spectroscopy is used to characterize bonding, but often the overall structure can be ambiguous. Our strategy is to combine a compliment of techniques, including AFM, XPS, XRR(X-ray reflectivity), XSW(X-ray standing wave), XRF(X-ray fluorescence), and DFT(Density functional theory) to determine the atomic scale molecular configuration and packing density of Self-Assembled Monolayers (SAMs) grown on H-passivated Silicon. Our periodic DFT study of 4-bromo-phenyl-acetylene (BPA) predicts that the local packing density can affect the Br height by as much as 2 angstrom. XSW, which is used to measure the 3D Br distribution shows that the local structure is unchanged when the average SAM coverage is increased. This indicates the type of 2D island nucleation growth process being observed. Comparison between 4-bromostyrene (BrSty) and BPA SAMs provides direct evidence that the double bond root of the BPA contributes to a stiffer configuration than the single bond root. With the aromatic rings in the structure for conducting electrons, BrSty and BPA molecules are a starting point for future molecular electronic designs with more complex molecules.

  11. Portable x-ray fluorescence spectrometer for environmental monitoring of inorganic pollutants

    NASA Technical Reports Server (NTRS)

    Thornton, Michael G. (Inventor); Clark, III, Benton C. (Inventor)

    1991-01-01

    A portable x-ray fluorescence spectrometer has a portable sensor unit containing a battery, a high voltage power supply, an x-ray tube which produces a beam x-ray radiation directed toward a target sample, and a detector for fluorescent x-rays produced by the sample. If a silicon-lithium detector is used, the sensor unit also contains either a thermoelectric or thermochemical cooler, or a small dewar flask containing liquid nitrogen to cool the detector. A pulse height analyzer (PHA) generates a spectrum of data for each sample consisting of the number of fluorescent x-rays detected as a function of their energy level. The PHA can also store spectrum data for a number of samples in the field. A processing unit can be attached to the pulse height analyzer to upload and analyze the stored spectrum data for each sample. The processing unit provides a graphic display of the spectrum data for each sample, and provides qualitative and/or quantitative analysis of the elemental composition of the sample by comparing the peaks in the sample spectrum against known x-ray energies for various chemical elements. An optional filtration enclosure can be used to filter particles from a sample suspension, either in the form of a natural suspension or a chemically created precipitate. The sensor unit is then temporarily attached to the filtration unit to analyze the particles collected by the filter medium.

  12. A Comprehensive X-Ray Absorption Model for Atomic Oxygen

    NASA Astrophysics Data System (ADS)

    Gorczyca, T. W.; Bautista, M. A.; Hasoglu, M. F.; García, J.; Gatuzz, E.; Kaastra, J. S.; Kallman, T. R.; Manson, S. T.; Mendoza, C.; Raassen, A. J. J.; de Vries, C. P.; Zatsarinny, O.

    2013-12-01

    An analytical formula is developed to accurately represent the photoabsorption cross section of O I for all energies of interest in X-ray spectral modeling. In the vicinity of the K edge, a Rydberg series expression is used to fit R-matrix results, including important orbital relaxation effects, that accurately predict the absorption oscillator strengths below threshold and merge consistently and continuously to the above-threshold cross section. Further, minor adjustments are made to the threshold energies in order to reliably align the atomic Rydberg resonances after consideration of both experimental and observed line positions. At energies far below or above the K-edge region, the formulation is based on both outer- and inner-shell direct photoionization, including significant shake-up and shake-off processes that result in photoionization-excitation and double-photoionization contributions to the total cross section. The ultimate purpose for developing a definitive model for oxygen absorption is to resolve standing discrepancies between the astronomically observed and laboratory-measured line positions, and between the inferred atomic and molecular oxygen abundances in the interstellar medium from XSTAR and SPEX spectral models.

  13. Fluorescence X-ray micro-spectroscopy activities at ESRF

    NASA Astrophysics Data System (ADS)

    Salomé, M.; Bleuet, P.; Bohic, S.; Cauzid, J.; Chalmin, E.; Cloetens, P.; Cotte, M.; De Andrade, V.; Martinez-Criado, G.; Petitgirard, S.; Rak, M.; Sans Tresserras, J. A.; Szlachetko, J.; Tucoulou, R.; Susini, J.

    2009-09-01

    The X-ray Microscopy and Micro-analysis beamlines at ESRF operate complementary state-of-the-art instruments at ID21, ID22, ID18F and more recently ID22NI. Within a multi-modal strategy, these beamlines develop micro-imaging techniques with various contrast mechanisms (?XRF, ?XANES, ?XRD and phase contrast) and host experiments with scientific topics ranging from Geochemistry to Archeology, Environmental sciences, Biology and Material sciences. Future challenges include pushing spatial resolution down to the nano-scale and the development of innovative 3D micro-analysis techniques.

  14. Design and characterization of a pulsed x-ray source for fluorescent lifetime measurements

    SciTech Connect

    Blankespoor, S.C. [Univ. of California, Berkeley, CA (United States). Dept. of Electrical Engineering and Computer Science]|[Lawrence Berkeley Lab., CA (United States)

    1993-12-01

    To search for new, fast, inorganic scintillators, the author and his colleagues have developed a bench-top pulsed x-ray source for determining fluorescent lifetimes and wavelengths of compounds in crystal or powdered form. This source uses a light-excited x-ray tube which produces x-rays when light from a laser diode strikes its photocathode. The x-ray tube has a tungsten anode, a beryllium exit window, a 30 kV maximum tube bias, and a 50 HA maximum average cathode current. The laser produces 3 {times} 10{sup 7} photons at 650 nm per {approximately}100 ps pulse, with up to 10{sup 7} pulses/sec. The time spread for the laser diode, x-ray tube, and a microchannel plate photomultiplier tube is less than 120 ps fwhm. The mean x-ray photon energy, at tube biases of 20, 25, and 30 kV, is 9.4, 10.3, and 11.1 keV, respectively. They measured 140, 230, and 330 x-ray photons per laser diode pulse per steradian at tube biases of 20, 25, and 30 kV, respectively. Background x-rays due to dark current occur at a rate of 1 {times} 10{sup 6} and 3 {times} 10{sup 6} photons/sec/steradian at tube biases of 25 and 30 kV, respectively. Data characterizing the x-ray output with an aluminum filter in the x-ray beam are also presented.

  15. Demonstration of x-ray fluorescence imaging of a high-energy-density plasma

    NASA Astrophysics Data System (ADS)

    MacDonald, M. J.; Keiter, P. A.; Montgomery, D. S.; Biener, M. M.; Fein, J. R.; Fournier, K. B.; Gamboa, E. J.; Klein, S. R.; Kuranz, C. C.; LeFevre, H. J.; Manuel, M. J.-E.; Streit, J.; Wan, W. C.; Drake, R. P.

    2014-11-01

    Experiments at the Trident Laser Facility have successfully demonstrated the use of x-ray fluorescence imaging (XRFI) to diagnose shocked carbonized resorcinol formaldehyde (CRF) foams doped with Ti. One laser beam created a shock wave in the doped foam. A second laser beam produced a flux of vanadium He-? x-rays, which in turn induced Ti K-shell fluorescence within the foam. Spectrally resolved 1D imaging of the x-ray fluorescence provided shock location and compression measurements. Additionally, experiments using a collimator demonstrated that one can probe specific regions within a target. These results show that XRFI is a capable alternative to path-integrated measurements for diagnosing hydrodynamic experiments at high energy density.

  16. Demonstration of x-ray fluorescence imaging of a high-energy-density plasma

    SciTech Connect

    MacDonald, M. J., E-mail: macdonm@umich.edu; Gamboa, E. J. [Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Keiter, P. A.; Fein, J. R.; Klein, S. R.; Kuranz, C. C.; LeFevre, H. J.; Manuel, M. J.-E.; Wan, W. C.; Drake, R. P. [Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Montgomery, D. S. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Biener, M. M.; Fournier, K. B. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Streit, J. [Schafer Corporation, Livermore, California 94551 (United States)

    2014-11-15

    Experiments at the Trident Laser Facility have successfully demonstrated the use of x-ray fluorescence imaging (XRFI) to diagnose shocked carbonized resorcinol formaldehyde (CRF) foams doped with Ti. One laser beam created a shock wave in the doped foam. A second laser beam produced a flux of vanadium He-? x-rays, which in turn induced Ti K-shell fluorescence within the foam. Spectrally resolved 1D imaging of the x-ray fluorescence provided shock location and compression measurements. Additionally, experiments using a collimator demonstrated that one can probe specific regions within a target. These results show that XRFI is a capable alternative to path-integrated measurements for diagnosing hydrodynamic experiments at high energy density.

  17. Quantitative measurement of binary liquid distributions using multiple-tracer x-ray fluorescence and radiography.

    PubMed

    Halls, Benjamin R; Meyer, Terrence R; Kastengren, Alan L

    2015-01-26

    The complex geometry and large index-of-refraction gradients that occur near the point of impingement of binary liquid jets present a challenging environment for optical interrogation. A simultaneous quadruple-tracer x-ray fluorescence and line-of-sight radiography technique is proposed as a means of distinguishing and quantifying individual liquid component distributions prior to, during, and after jet impact. Two different pairs of fluorescence tracers are seeded into each liquid stream to maximize their attenuation ratio for reabsorption correction and differentiation of the two fluids during mixing. This approach for instantaneous correction of x-ray fluorescence reabsorption is compared with a more time-intensive approach of using stereographic reconstruction of x-ray attenuation along multiple lines of sight. The proposed methodology addresses the need for a quantitative measurement technique capable of interrogating optically complex, near-field liquid distributions in many mixing systems of practical interest involving two or more liquid streams. PMID:25835928

  18. Multi-angular regolith effects on planetary soft X-ray fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Näränen, J.; Parviainen, H.; Carpenter, J.; Muinonen, K.

    2009-04-01

    Fluorescent X-rays from the surfaces of airless planetary bodies in the inner solar system have been measured by instruments on several spacecraft. MESSENGER carries an X-ray spectrometer (XRS) on-board and has already attempted to obtain fluorescent X-rays from the Hermean surface. BepiColombo will later on carry an X-ray telescope (MIXS-T) along with a more conventional collimating detector (MIXS-C) to the Hermean orbit, supported by a next-generation X-ray solar monitor (SIXS). These instruments will provide unprecedented knowledge about the geochemical properties of the Hermean regolith. X-ray emission from planetary surfaces follows photoionisation by incident solar X-rays and charged particles and reveals information about the elemental composition of the surface. Analyses of X-ray spectra, obtained by orbiting spacecraft, use both the relative intensities of elemental emission lines (e.g., Ca/Si, Fe/Si) and absolute abundancies of the elements to determine the geochemistry of the target body. Historically, the analysis of X-ray spectra has largely assumed that surfaces can be considered as homogeneous plane-parallel media. It has been shown, however, that fluorescent line intensities are affected by the physical properties of the target surface (e.g., surface roughness of the regolith) as a function of the viewing and illumination geometry of observations in a way that cannot be explained by the traditional models. We describe experimental investigations where we simulated the effects of regolith properties on the fluorescent lines measured by an orbiting instrument, with a large variety of illumination and viewing angles. The planetary regolith analogue used in these experiments was a terrestrial, olivine rich basalt, which has been used by previous authors as an analogue to the lunar maria. The basalt samples were ground to powder and sieved to discriminate particles in the ranges, <75 micrometers, 75-250 micrometers, and 250-500 micrometers. These separate powders were then pressed into solid pellets. The separation of particles with different sizes allows some determination of the effects due to changes in, e.g., surface roughness. The pellets were imaged with a CT scanner to obtain the physical parameters of the samples. All measurements were made at near-vacuum pressures to prevent absorption of fluorescent X-rays in air. The relative fluorescent line ratios of several major rock-forming elements (e.g., Si, K, Ca, Ti, Fe) were measured. In addition to experimental studies we have simulated the X-ray emission from a regolith using a numerical Monte-Carlo ray-tracing model. This model simulates a regolith of spherical particles, with defined physical properties (particle size distribution, packing density, etc.) and with a realistic macro-scale surface roughness characteristics generated by constraining the surface with a fractional-Brownian-motion surface model. A comparison is made between the modelling and experimental results to validate the modelling. A good agreement between the results is found. We find that both the measured and the simulated spectra become increasingly hard as the phase angle increases (i.e., X-ray lines at higher energies are enhanced relative to those at lower energies). Some hardening of spectra is predicted by the fundamental parameters equation (FPE) of X-ray fluorescence, which assumes a smooth, flat, and homogeneous surface, but we observe further spectral hardening that is in excess to that predicted by the FPE and that this excess hardening is also a function of the surface roughness. We propose to use modelling similar to ours for the data analysis of soft X-ray fluorescence spectra to take the multi-angular effects related to the physical properties of the regolith into account.

  19. Application of the high-resolution grazing-emission x-ray fluorescence method for impurities control in semiconductor nanotechnology

    NASA Astrophysics Data System (ADS)

    Szlachetko, J.; Bana?, D.; Kubala-Kuku?, A.; Pajek, M.; Cao, W.; Dousse, J.-Cl.; Hoszowska, J.; Kayser, Y.; Szlachetko, M.; Kav?i?, M.; Salome, M.; Susini, J.

    2009-04-01

    We report on the application of synchrotron radiation based high-resolution grazing-emission x-ray fluorescence (GEXRF) method to measure low-level impurities on silicon wafers. The presented high-resolution GEXRF technique leads to direct detection limits of about 1012 atoms/cm2. The latter can be presumably further improved down to 107 atoms/cm2 by combining the synchrotron radiation-based GEXRF method with the vapor phase decomposition preconcentration technique. The capability of the high-resolution GEXRF method to perform surface-sensitive elemental mappings with a lateral resolution of several tens of micrometers was probed.

  20. Application of the high-resolution grazing-emission x-ray fluorescence method for impurities control in semiconductor nanotechnology

    SciTech Connect

    Szlachetko, J. [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); European Synchrotron Radiation Facility (ESRF), F-38043 Grenoble (France); Banas, D.; Kubala-Kukus, A.; Pajek, M. [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Cao, W.; Dousse, J.-Cl.; Hoszowska, J.; Kayser, Y.; Szlachetko, M. [Department of Physics, University of Fribourg, CH-1700 Fribourg (Switzerland); Kavcic, M. [J. Stefan Institute, SI-1001, Ljubljana (Slovenia); Salome, M.; Susini, J. [European Synchrotron Radiation Facility (ESRF), F-38043 Grenoble (France)

    2009-04-15

    We report on the application of synchrotron radiation based high-resolution grazing-emission x-ray fluorescence (GEXRF) method to measure low-level impurities on silicon wafers. The presented high-resolution GEXRF technique leads to direct detection limits of about 10{sup 12} atoms/cm{sup 2}. The latter can be presumably further improved down to 10{sup 7} atoms/cm{sup 2} by combining the synchrotron radiation-based GEXRF method with the vapor phase decomposition preconcentration technique. The capability of the high-resolution GEXRF method to perform surface-sensitive elemental mappings with a lateral resolution of several tens of micrometers was probed.

  1. Grazing-emission X-ray fluorescence spectrometry; principles and applications

    NASA Astrophysics Data System (ADS)

    de Bokx, P. K.; Kok, Chr.; Bailleul, A.; Wiener, G.; Urbach, H. P.

    1997-07-01

    In grazing-emission X-ray fluorescence spectrometry (GEXRF), the sample is irradiated at approximately normal incidence, and only that part of the fluorescence radiation is detected that is emitted at grazing angles. This configuration allows the use of wavelength-dispersive detection. This type of detection has the advantages of substantially better energy resolution at longer wavelengths (light elements, L and M lines of heavier elements) and a much larger dynamic range than the energy-dispersive detectors currently used in grazing X-ray techniques. Typical examples are presented of applications that are made possible by this new technique.

  2. Lunar X-ray fluorescence observations by the Chandrayaan-1 X-ray Spectrometer (C1XS): Results from the nearside southern highlands

    NASA Astrophysics Data System (ADS)

    Narendranath, S.; Athiray, P. S.; Sreekumar, P.; Kellett, B. J.; Alha, L.; Howe, C. J.; Joy, K. H.; Grande, M.; Huovelin, J.; Crawford, I. A.; Unnikrishnan, U.; Lalita, S.; Subramaniam, S.; Weider, S. Z.; Nittler, L. R.; Gasnault, O.; Rothery, D.; Fernandes, V. A.; Bhandari, N.; Goswami, J. N.; Wieczorek, M. A.; the C1XS Team

    2011-07-01

    The Chandrayaan-1 X-ray Spectrometer (C1XS) flown on-board the first Indian lunar mission Chandrayaan-1, measured X-ray fluorescence spectra during several episodes of solar flares during its operational period of ˜9 months. The accompanying X-ray Solar Monitor (XSM) provided simultaneous spectra of solar X-rays incident on the Moon which are essential to derive elemental chemistry. In this paper, we present the surface abundances of Mg, Al, Si, Ca and Fe, derived from C1XS data for a highland region on the southern nearside of the Moon. Analysis techniques are described in detail including absolute X-ray line flux derivation and conversion into elemental abundance. The results are consistent with a composition rich in plagioclase with a slight mafic mineral enhancement and a Ca/Al ratio that is significantly lower than measured in lunar returned samples. We suggest various possible scenarios to explain the deviations.

  3. Chandra and XMM-Newton: Atomic Data Needs For X-ray Astronomy

    NASA Technical Reports Server (NTRS)

    Brickhouse, Nancy

    2000-01-01

    With the launches of the Chandra X-ray Observatory and XM M-Newton, high resolution X-ray spectra of cosmic sources are broadening our understanding of the physical conditions, such as temperature, density, Ionization state, and elemental abundances. X-ray emitting astrophysical plasmas can be generally classified by their dominant ionization mechanism, either collisional ionization or X-ray photoionization. The atomic data needs are significantly different for these two cases; however, for both cases it is important that we identify robust and accurate diagnostics and that we verify completeness of the broadband models. We discuss the status of tile atomic data currently used in atomic databases for X-ray astronomy, in view of theoretical and experimental atomic physics considerations. We will also discuss the application of these models to new astrophysical data.

  4. Fluorescence yield X-ray absorption spectroscopy for OK ? with elimination of NK ? background using superconducting tunnel junction detectors

    Microsoft Academic Search

    S. Shiki; M. Ukibe; Y. Kitajima; M. Ohkubo

    2011-01-01

    Fluorescent yield X-ray absorption fine structure (XAFS) spectroscopy is widely used for measuring chemical or physical states of particular elements in materials. A superconducting tunnel junction (STJ) detector is promising for X-ray absorption spectroscopy, especially in a soft X-ray region below 1keV, because of an excellent energy resolution of 10–20eV, which is crucial for resolving the characteristic X-ray lines from

  5. Femtosecond electronic response of atoms to ultra-intense X-rays

    Microsoft Academic Search

    L. Young; E. P. Kanter; B. Krässig; Y. Li; A. M. March; S. T. Pratt; R. Santra; S. H. Southworth; N. Rohringer; L. F. Dimauro; G. Doumy; C. A. Roedig; N. Berrah; L. Fang; M. Hoener; P. H. Bucksbaum; J. P. Cryan; S. Ghimire; J. M. Glownia; D. A. Reis; J. D. Bozek; C. Bostedt; M. Messerschmidt

    2010-01-01

    An era of exploring the interactions of high-intensity, hard X-rays with matter has begun with the start-up of a hard-X-ray free-electron laser, the Linac Coherent Light Source (LCLS). Understanding how electrons in matter respond to ultra-intense X-ray radiation is essential for all applications. Here we reveal the nature of the electronic response in a free atom to unprecedented high-intensity, short-wavelength,

  6. Laboratory x-ray fluorescence tomography for high-resolution nanoparticle bio-imaging.

    PubMed

    Hertz, Hans M; Larsson, Jakob C; Lundström, Ulf; Larsson, Daniel H; Vogt, Carmen

    2014-05-01

    We demonstrate that nanoparticle x-ray fluorescence computed tomography in mouse-sized objects can be performed with very high spatial resolution at acceptable dose and exposure times with a compact laboratory system. The method relies on the combination of the 24 keV line-emission from a high-brightness liquid-metal-jet x-ray source, pencil-beam-forming x-ray optics, photon-counting energy-dispersive detection, and carefully matched (Mo) nanoparticles. Phantom experiments and simulations show that the arrangement significantly reduces Compton background and allows 100 ?m detail imaging at dose and exposure times compatible with small-animal experiments. The method provides a possible path to in vivo molecular x-ray imaging at sub-100 ?m resolution in mice. PMID:24784104

  7. A depth profile fitting model for a commercial total reflection X-ray fluorescence spectrometer

    NASA Astrophysics Data System (ADS)

    Mori, Yoshihiro; Uemura, Kenichi; Shimanoe, Kengo

    1997-07-01

    We have proposed a practical depth profiling model for a commercial Total Reflection X-Ray Fluorescence (TXRF) spectrometry instrument. The model includes three factors peculiar to a commercial TXRF instrument: (a) the irradiated X-ray photon density on the sample surface depends on a glancing angle, (b) the X-ray irradiated area becomes smaller than the detector view over a certain glancing angle, and (c) the incident X-ray has angular divergence. This model was optimized by comparing the measured Si-K? for a silicon wafer with the calculated one. The results indicated that all of the three factors are indispensable for our instrument. We have applied this model to a surface contaminant and discussed its adequacy.

  8. Atomic inner-shell X-ray laser at 1.46 nanometres pumped by an X-ray free-electron laser.

    PubMed

    Rohringer, Nina; Ryan, Duncan; London, Richard A; Purvis, Michael; Albert, Felicie; Dunn, James; Bozek, John D; Bostedt, Christoph; Graf, Alexander; Hill, Randal; Hau-Riege, Stefan P; Rocca, Jorge J

    2012-01-26

    Since the invention of the laser more than 50 years ago, scientists have striven to achieve amplification on atomic transitions of increasingly shorter wavelength. The introduction of X-ray free-electron lasers makes it possible to pump new atomic X-ray lasers with ultrashort pulse duration, extreme spectral brightness and full temporal coherence. Here we describe the implementation of an X-ray laser in the kiloelectronvolt energy regime, based on atomic population inversion and driven by rapid K-shell photo-ionization using pulses from an X-ray free-electron laser. We established a population inversion of the K? transition in singly ionized neon at 1.46 nanometres (corresponding to a photon energy of 849 electronvolts) in an elongated plasma column created by irradiation of a gas medium. We observed strong amplified spontaneous emission from the end of the excited plasma. This resulted in femtosecond-duration, high-intensity X-ray pulses of much shorter wavelength and greater brilliance than achieved with previous atomic X-ray lasers. Moreover, this scheme provides greatly increased wavelength stability, monochromaticity and improved temporal coherence by comparison with present-day X-ray free-electron lasers. The atomic X-ray lasers realized here may be useful for high-resolution spectroscopy and nonlinear X-ray studies. PMID:22281598

  9. Application of XFEL to the measurement of x-ray flux irradiating bio-molecules by using x-ray emission from hollow atoms produced from multiple x-ray absorption

    Microsoft Academic Search

    Kengo Moribayashi

    2008-01-01

    We propose the measurement of x-ray flux irradiating bio-molecules by the theoretical treatment of atomic processes together with multiple x-ray absorption. This measurement is useful for the application of x-ray free electron lasers to the measurement of diffraction patterns of bio-molecules, which is indispensable for the study of their three-dimensional structure. The charge numbers of atoms such as C, N,

  10. First X-ray Fluorescence MicroCT Results from Micrometeorites at SSRL

    SciTech Connect

    Ignatyev, K; Huwig, K; Harvey, R; Ishii, H; Bradley, J; Luening, K; Brennan, S; Pianetta, P

    2006-08-23

    X-ray fluorescence microCT (computed tomography) is a novel technique that allows non-destructive determination of the 3D distribution of chemical elements inside a sample. This is especially important in samples for which sectioning is undesirable either due to the risk of contamination or the requirement for further analysis by different characterization techniques. Developments made by third generation synchrotron facilities and laboratory X-ray focusing systems have made these kinds of measurements more attractive by significantly reducing scan times and beam size. First results from the x-ray fluorescence microCT experiments performed at SSRL beamline 6-2 are reported here. Beamline 6-2 is a 54 pole wiggler that uses a two mirror optical system for focusing the x-rays onto a virtual source slit which is then reimaged with a set of KB mirrors to a (2 x 4) {micro}{sup 2} beam spot. An energy dispersive fluorescence detector is located in plane at 90 degrees to the incident beam to reduce the scattering contribution. A PIN diode located behind the sample simultaneously measures the x-ray attenuation in the sample. Several porous micrometeorite samples were measured and the reconstructed element density distribution including self-absorption correction is presented. Ultimately, this system will be used to analyze particles from the coma of comet Wild-2 and fresh interstellar dust particles both of which were collected during the NASA Stardust mission.

  11. First X-ray Fluorescence MicroCT Results from Micrometeorites at SSRL

    SciTech Connect

    Ignatyev, Konstantin; Luening, Katharina; Brennan, Sean; Pianetta, Piero [Stanford Synchrotron Radiation Laboratory, 2575 Sand Hill Rd, Menlo Park, CA 94025 (United States); Huwig, Kathy; Harvey, Ralph [Case Western Reserve University, Cleveland, OH 44106 (United States); Ishii, Hope; Bradley, John [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States)

    2007-01-19

    X-ray fluorescence microCT (computed tomography) is a novel technique that allows non-destructive determination of the 3D distribution of chemical elements inside a sample. This is especially important in samples for which sectioning is undesirable either due to the risk of contamination or the requirement for further analysis by different characterization techniques. Developments made by third generation synchrotron facilities and laboratory X-ray focusing systems have made these kinds of measurements more attractive by significantly reducing scan times and beam size. First results from the x-ray fluorescence microCT experiments performed at SSRL beamline 6-2 are reported here. Beamline 6-2 is a 54 pole wiggler that uses a two mirror optical system for focusing the x-rays onto a virtual source slit which is then reimaged with a set of KB mirrors to a (2 x 4) {mu}m2 beam spot. An energy dispersive fluorescence detector is located in plane at 90 degrees to the incident beam to reduce the scattering contribution. A PIN diode located behind the sample simultaneously measures the x-ray attenuation in the sample. Several porous micrometeorite samples were measured and the reconstructed element density distribution including self-absorption correction is presented. Ultimately, this system will be used to analyze particles from the coma of comet Wild-2 and fresh interstellar dust particles both of which were collected during the NASA Stardust mission.

  12. X-ray fluorescence computed tomography (XFCT) imaging of gold nanoparticle-loaded objects using 110 kVp x-rays

    Microsoft Academic Search

    Seong-Kyun Cheong; Bernard L. Jones; Arsalan K. Siddiqi; Fang Liu; Nivedh Manohar; Sang Hyun Cho

    2010-01-01

    A conventional x-ray fluorescence computed tomography (XFCT) technique requires monochromatic synchrotron x-rays to simultaneously determine the spatial distribution and concentration of various elements such as metals in a sample. However, the synchrotron-based XFCT technique appears to be unsuitable for in vivo imaging under a typical laboratory setting. In this study we demonstrated, for the first time to our knowledge, the

  13. Tabletop Ultrabright Kiloelectronvolt X-Ray Sources from Xe and Kr Hollow Atom States

    NASA Astrophysics Data System (ADS)

    Sankar, Poopalasingam

    Albert Einstein, the father of relativity, once said, "Look deep into nature, and then you will understand everything better". Today available higher resolution tabletop tool to look deep into matters and living thing is an x-ray source. Although the available tabletop x-rays sources of the 20th century, such as the ones used for medical or dental x-rays are tremendously useful for medical diagnostics and industry, a major disadvantage is that they have low quality skillful brightness, which limits its resolution and accuracy. In the other hand, x-ray free-electrons laser (XFEL) and synchrotron radiation sources provided extreme bright x-rays. However, number of applications of XFEL and synchrotron such as medical and industrials, has been hampered by their size, complexity, and cost. This has set a goal of demonstrating x-ray source with enough brightness for potential applications in an often-called tabletop compact x-ray source that could be operated in university laboratory or hospitals. We have developed two tabletop ultrabright keV x-ray sources, one from a Xe hollow-atom states and the other one from Kr hollow-atom stares with a unique characteristic that makes them complementary to currently-available extreme-light sources; XFEL, and synchrotron x-ray source. Upgraded tabletop ultra-fast KrF* pump-laser interacts with target rare-gas clusters and produces hollow-atom states, which later coherently collapse to the empty inner-shell and thereby generate keV x-ray radiation. The KrF* pump-laser beam is self-focused and forms a self-channel to guide the generated x-ray radiation in the direction of the pump-laser beam to produce directed x-ray beam. Xe (M) x-ray source operates at 1.2-1.6 nm wavelength while the Kr(L) x-ray source operates in 600-800 pm wavelength. System is mounted upon 3 optical-tables (5´x12´) with two KrF amplifiers at a repetition rate of 0.1 Hz. A lower bound for brightness value for both Xe and Kr x-ray sources is 1026 photons s-1mm-2mrad-2 0. This is greater than average brightness (1022 photons s-1mm -2mrad-2 0. 1% BW) of the available x-ray free electron lasers and synchrotron x-ray sources.

  14. Development of a compact grazing exit X-ray fluorescence spectrometer for fast trace elemental analysis

    NASA Astrophysics Data System (ADS)

    Ashida, Takafumi; Tsuji, Kouichi

    2014-11-01

    A compact grazing exit X-ray fluorescence (GE-XRF) spectrometer was developed in the laboratory. An Al cylindrical collimator for the primary X-rays was placed just above the sample stage. This collimator also played the role of an exit slit to detect fluorescent X-rays at small grazing exit angles. Therefore, no additional exit slit was used in this setup, leading to a compact design. The entire size of the analysis equipment was 80 mm × 200 mm × 170 mm (horizontal × vertical × height). The maximum exit angle was adjusted to the height of the sample stage. The background was drastically reduced at grazing exit angles, enabling trace elemental analysis. A calibration curve was obtained using 10 ?L Ga solutions. Accordingly, the detection limit for Ga was evaluated to be 20 ppb.

  15. Nanoparticle characterization by means of scanning free grazing emission X-ray fluorescence.

    PubMed

    Kayser, Yves; Sá, Jacinto; Szlachetko, Jakub

    2015-05-14

    Nanoparticles are considered for applications in domains as various as medical and pharmaceutical sciences, opto- and microelectronics, catalysis, photovoltaics, spintronics or nano- and biotechnology. The applications realized with nanocrystals depend strongly on the physical dimensions (shape and size) and elemental constitution. We demonstrate here that grazing emission X-ray fluorescence (GEXRF) is an element sensitive technique that presents the potential for a reliable and accurate determination of the morphology of nanoparticles deposited on a flat substrate (ready-to-use devices). Thanks to the scanning-free approach of the used GEXRF setup, the composition, shape and average size of nanoparticles are determined in short time intervals, minimizing the exposure to radiation. The (scanning-free) GEXRF technique allows for in situ investigations of the nanoparticulate systems thanks to the penetration properties of both the probe X-ray beam and the emitted X-ray fluorescence signal. PMID:25946258

  16. Nanoparticle characterization by means of scanning free grazing emission X-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Kayser, Yves; Sá, Jacinto; Szlachetko, Jakub

    2015-05-01

    Nanoparticles are considered for applications in domains as various as medical and pharmaceutical sciences, opto- and microelectronics, catalysis, photovoltaics, spintronics or nano- and biotechnology. The applications realized with nanocrystals depend strongly on the physical dimensions (shape and size) and elemental constitution. We demonstrate here that grazing emission X-ray fluorescence (GEXRF) is an element sensitive technique that presents the potential for a reliable and accurate determination of the morphology of nanoparticles deposited on a flat substrate (ready-to-use devices). Thanks to the scanning-free approach of the used GEXRF setup, the composition, shape and average size of nanoparticles are determined in short time intervals, minimizing the exposure to radiation. The (scanning-free) GEXRF technique allows for in situ investigations of the nanoparticulate systems thanks to the penetration properties of both the probe X-ray beam and the emitted X-ray fluorescence signal.

  17. 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.

  18. The Neoplastic Transformation Potential of Mammography X Rays and Atomic Bomb Spectrum Radiation

    Microsoft Academic Search

    G. J. Heyes; A. J. Mill

    2004-01-01

    Heyes, G. H. and Mill, A. J. The Neoplastic Transformation Potential of Mammography X Rays and Atomic Bomb Spec- trum Radiation. Radiat. Res. 162, 120-127 (2004). Considerable controversy currently exists regarding the bi- ological effectiveness of 29 kVp X rays which are used for mammography screening. This issue must be resolved to en- able proper evaluation of radiation risks from

  19. Detection limits for actinides in a monochromatic, wavelength-dispersive x-ray fluorescence instrument

    SciTech Connect

    Collins, Michael L [Los Alamos National Laboratory; Havrilla, George J [Los Alamos National Laboratory

    2009-01-01

    Recent developments in x-ray optics have made it possible to examine the L x-rays of actinides using doubly-curved crystals in a bench-top device. A doubly-curved crystal (DCC) acts as a focusing monochromatic filter for polychromatic x-rays. A Monochromatic, Wavelength-Dispersive X-Ray Fluorescence (MWDXRF) instrument that uses DCCs to measure Cm and Pu in reprocessing plant liquors was proposed in 2007 by the authors at Los Alamos National Laboratory. A prototype design of this MWDXRF instrument was developed in collaboration with X-ray Optical Systems Inc. (XOS), of East Greenbush, New York. In the MWDXRF instrument, x-rays from a Rhodium-anode x-ray tube are passed through a primary DCC to produce a monochromatic beam of 20.2-keV photons. This beam is focused on a specimen that may contain actinides. The 20.2-keV interrogating beam is just above the L3 edge of Californium; each actinide (with Z = 90 to 98) present in the specimen emits characteristic L x-rays as the result of L3-shell vacancies. In the LANL-XOS prototype MWDXRf, these x-rays enter a secondary DCC optic that preferentially passes 14.961-keV photons, corresponding to the L-alpha-1 x-ray peak of Curium. In the present stage of experimentation, Curium-bearing specimens have not been analyzed with the prototype MWDXRF instrument. Surrogate materials for Curium include Rubidium, which has a K-beta-l x-ray at 14.961 keV, and Yttrium, which has a K-alpha-1 x-ray at 14.958 keV. In this paper, the lower limit of detection for Curium in the LANL-XOS prototype MWDXRF instrument is estimated. The basis for this estimate is described, including a description of computational models and benchmarking techniques used. Detection limits for other actinides are considered, as well as future safeguards applications for MWDXRF instrumentation.

  20. Determining the Conformation of an Adsorbed Br-PEG-Peptide by Long Period X-ray Standing Wave Fluorescence

    PubMed Central

    Crot, Carrie A.; Wu, Chunping; Schlossman, Mark L.; Trainor, Thomas P.; Eng, Peter J.; Hanley, Luke

    2008-01-01

    Long period x-ray standing wave fluorescence (XSW) and x-ray reflectivity techniques are employed to probe the conformation of a Br-polyethylene glycol (PEG)-peptide adsorbate at the hydrated interface of a polystyrene substrate. The Br atom on this Br-PEG-peptide construct serves as a marker atom allowing determination by XSW of its position and distribution with respect to the adsorption surface with angstrom resolution. Adsorption occurs on native or ion beam modified polystyrene films that are spin coated onto a Si substrate and display either nonpolar or polar surfaces, respectively. A compact, oriented monolayer of Br-PEG-peptide can be formed with the peptide end adsorbed onto the polar surface and the PEG end terminating with the Br tag extending into the aqueous phase. The 108 – 141 Å distance of the Br atom from the polystyrene surface in this oriented monolayer is similar to the estimated ~150 Å length of the extended Br-PEG-peptide. This Br-polystyrene distance depends upon adsorption time and surface properties prior to adsorption. Incomplete multilayers form on the polar surface after sufficient adsorption time elapses. By contrast, adsorption onto the nonpolar surface is submonolayer, patchy, and highly disordered with an isotropic Br distribution. Overall, this combination of x-ray surface scattering techniques with a novel sample preparation strategy has several advantages as a real space probe of adsorbed or covalently bound biomolecules at the liquid-solid interface. PMID:16089398

  1. Depth profiles of Al impurities implanted in Si wafers determined by means of the high-resolution grazing emission X-ray fluorescence technique

    NASA Astrophysics Data System (ADS)

    Kayser, Y.; Bana?, D.; Cao, W.; Dousse, J.-Cl.; Hoszowska, J.; Jagodzi?ski, P.; Kav?i?, M.; Kubala-Kuku?, A.; Nowak, S.; Pajek, M.; Szlachetko, J.

    2010-06-01

    The synchrotron radiation based high-resolution grazing emission X-ray fluorescence (GEXRF) technique was used to extract the distribution of Al ions implanted with a dose of 10 16 atoms/cm 2 in Si wafers with energies ranging between 1 and 100 keV. The depth distributions of the implanted ions were deduced from the measured angular profiles of the Al-K ? X-ray fluorescence line with nanometer-scale precision. The experimental results were compared to theoretical predictions of the depth distributions resulting from ion implantation. A good agreement between experiment and theory was found which proved that the presented high-resolution grazing emission X-ray fluorescence technique is well suited to perform depth profiling measurements of impurities located within the extinction depth, provided the overall shape of the distribution can be assumed a priori.

  2. Quantitative X-ray fluorescence analysis of As-Se glasses and films

    NASA Astrophysics Data System (ADS)

    Bordovski?, G. A.; Marchenko, A. V.; Seregin, P. P.; Smirnova, N. N.; Terukov, E. I.

    2009-11-01

    The concentrations of arsenic and selenium in As100 - x Se x glassy alloys and related films have been determined by the X-ray fluorescence spectroscopy using the external standard technique. It is demonstrated that the proposed approach allows the compositions of As100 - x Se x glasses and films to be quantitatively determined with an accuracy of ? x = ±0.02.

  3. X-RAY FLUORESCENCE ANALYSIS OF FILTER-COLLECTED AEROSOL PARTICLES

    EPA Science Inventory

    X-ray fluorescence (XRF) has become an effective technique for determining the elemental content of aerosol samples. For quantitative analysis, the aerosol particles must be collected as uniform deposits on the surface of Teflon membrane filters. An energy dispersive XRF spectrom...

  4. X-ray fluorescence and multivariate analysis for sucrose quantification in sugarcane

    NASA Astrophysics Data System (ADS)

    Melquiades, Fábio L.; Bortoleto, Gisele G.; Neme, Fernanda F.; Ton, Ariel; Bueno, Maria I. M. S.

    2013-05-01

    Currently the methods used for determining the sucrose content in sugarcane are made in the clarified juice. In this study portable energy dispersive X-ray fluorescence (EDXRF) together with chemometric tools was used to quantify sucrose through the stem, lief and juice. The best results were obtained for the stem, with means relative deviation of around 6%.

  5. Detection of visible and latent fingerprints by micro-X-ray fluorescence

    Microsoft Academic Search

    Christopher G. Worley; Sara S. Wiltshire; Thomasin C. Miller; George J. Havrilla; Vahid Majidi

    2006-01-01

    Numerous methods are available to forensic scientists for detecting fingerprints in which the prints are treated with various agents to enhance the visual contrast between the print and the surface. In the present work, the spatial elemental imaging capabilities of micro-X-ray fluorescence (MXRF) were used to visualize fingerprint patterns based on inorganic elements present in the prints. A major advantage

  6. X-ray fluorescence analysis of malachite ore concentrates in the Narman region

    Microsoft Academic Search

    G. Budak; A Karabulut

    1999-01-01

    Analysis by energy dispersive X-ray fluorescence (EDXRF) spectroscopy of malachite ore of the Narman region in the city of Erzurum (Turkey) has been carried out for the determination of their elemental composition, using an annular 241Am radioisotope source. The elements Fe, Cu, Sr, Zr, In, Sn, Sb, I and Ba are analyzed. Samples are prepared from powder sifted by a

  7. In situ measurements of colloid transport and retention using synchrotron X-ray fluorescence

    E-print Network

    Walter, M.Todd

    In situ measurements of colloid transport and retention using synchrotron X-ray fluorescence David] The physics regarding the retention and mobilization of colloids in saturated and unsaturated conditions remains poorly understood, partially because of the inability to measure colloid concentrations in situ

  8. Simultaneous cryo X-ray ptychographic and fluorescence microscopy of green algae.

    PubMed

    Deng, Junjing; Vine, David J; Chen, Si; Nashed, Youssef S G; Jin, Qiaoling; Phillips, Nicholas W; Peterka, Tom; Ross, Rob; Vogt, Stefan; Jacobsen, Chris J

    2015-02-24

    Trace metals play important roles in normal and in disease-causing biological functions. X-ray fluorescence microscopy reveals trace elements with no dependence on binding affinities (unlike with visible light fluorophores) and with improved sensitivity relative to electron probes. However, X-ray fluorescence is not very sensitive for showing the light elements that comprise the majority of cellular material. Here we show that X-ray ptychography can be combined with fluorescence to image both cellular structure and trace element distribution in frozen-hydrated cells at cryogenic temperatures, with high structural and chemical fidelity. Ptychographic reconstruction algorithms deliver phase and absorption contrast images at a resolution beyond that of the illuminating lens or beam size. Using 5.2-keV X-rays, we have obtained sub-30-nm resolution structural images and ?90-nm-resolution fluorescence images of several elements in frozen-hydrated green algae. This combined approach offers a way to study the role of trace elements in their structural context. PMID:25675478

  9. Determination of argon in sputtered silicon films by energy-dispersive x-ray fluorescence spectrometry

    Microsoft Academic Search

    Dennis J. Kalnicky; T. D. Moustakas

    1981-01-01

    Hydrogenated amorphous silicon can be prepared by glow discharge decomposition of silane or by reactive sputtering in an argon + hydrogen plasma. The sputtered films contain some percentage of argon incorporated in them and its role in determining the physical properties of these materials is of interest. This paper describes energy-dispersive x-ray fluorescence (EDXRF) methods which were developed to characterize

  10. Mineral analysis of corn leaves by x?ray fluorescence on ground versus unground leaf samples

    Microsoft Academic Search

    Kenneth D. Frank; John Burch; Joseph Denning

    1992-01-01

    Plant tissue analysis for non?mobile nutrients can supplement soil test values or may replace soil analyses in the determination of the soil's ability to supply these nutrients to next year's crop. X?ray fluorescence (XRF) is a rapid technique for determining nutrient concentration in plant tissue. Typically, whole leaves are dried and ground for analysis by XRF or other chemical methods.

  11. Discriminating red spray paints by optical microscopy, Fourier transform infrared spectroscopy and X-ray fluorescence

    Microsoft Academic Search

    Filip Govaert; Magali Bernard

    2004-01-01

    Red spray paints from different European suppliers were characterised to determine the discriminating power of a sequence of analysing techniques. A total of 51 red spray paints were analysed with the help of three techniques: (1) optical microscopy, (2) Fourier transform infrared spectrometry and (3) X-ray fluorescence. Infrared spectra were classified according to binder type, filler and pigment composition and

  12. Thickness Measurement of Gold Film Coating on Glass Substrate by X-Ray Fluorescence Technique

    Microsoft Academic Search

    Nirun Witit-anuna; Pichet Limsuwan; Weerapong Chewpraditkul

    Thickness is considered as one of the important characteristics of thin film. Almost all of film properties are related to film thickness such as electrical resistance, reflectance and transmittance of light. The objective of this research work is to study the thickness measurement of thin film by using X-ray fluorescence technique. Gold film samples have been coated on glass substrates

  13. Polarized Energy Dispersive X-ray Fluorescence Applications of Spice Samples

    Microsoft Academic Search

    Zafer Üstünda?

    2009-01-01

    In this study, the elemental concentrations of some spice plants gathered from Mut-Mersin in Turkey were analyzed by polarized energy dispersive x-ray fluorescence (PEDXRF) spectrometry. The analyzed spices are peppermint (Mentha piperita), thyme (Thymus vulgaris), and sumac (Rhus glabra). These samples are very often used in the preparation of Turkish foods. The spice samples are indispensable in foods for Turkish

  14. A wavelength dispersive detector for synchrotron x-ray fluorescence microprobe analysis (abstract)

    Microsoft Academic Search

    Mark L. Rivers; Stephen R. Sutton

    1995-01-01

    The synchrotron x-ray fluorescence (SXRF) microprobe has proven to be a valuable tool for trace element research. It permits analysis down to a few parts per million of many elements in a spot size of less than 10 ?m. Existing SXRF microprobes are using energy dispersive detectors (EDS), either Si(Li) or intrinsic Ge diodes. Such detectors have the advantage of

  15. Determination of rhenium in molybdenite by X-ray fluorescence. A combined chemical-spectrometric technique

    USGS Publications Warehouse

    Solt, M.W.; Wahlberg, J.S.; Myers, A.T.

    1969-01-01

    Rhenium in molybdenite is separated from molybdenum by distillation of rhenium heptoxide from a perchloric-sulphuric acid mixture. It is concentrated by precipitation of the sulphide and then determined by X-ray fluorescence. From 3 to 1000 ??g of rhenium can be measured with a precision generally within 2%. The procedure tolerates larger amounts of molybdenum than the usual colorimetric methods. ?? 1969.

  16. EVALUATION OF A PROTOTYPE FIELD-PORTABLE X-RAY FLUORESCENCE SYSTEM FOR HAZARDOUS WASTE SCREENING

    EPA Science Inventory

    A prototype field-portable X-ray fluorescence system developed by EPA and NASA was evaluated at a site contaminated with Pb, Zn, and Cu. The objective of the field test was to evaluate the effectiveness of the instrument as a field analytical tool for locating hot spots and as a ...

  17. Rapid screening for zinc deficiency using portable x-ray fluorescence in fingernails

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Elemental composition of fingernails is a useful indicator of micronutrient status and may reflect an individual’s intake over time. Our objective was to determine if portable X-ray fluorescence (XRF) is a viable method to assess zinc content in fingernails in the field. Human fingernail samples ran...

  18. SCANNING ELECTRON MICROSCOPY/X-RAY FLUORESCENCE CHARACTERIZATION OF POST-ABATEMENT DUST

    EPA Science Inventory

    Scanning electron microscopy (SEM) and laboratory X-ray fluorescence (XRF) were used to characterize post-abatement dust collected with a HEPA filtered vacuum. hree size fractions of resuspended dust (0-30 pm, 2.5-15 pm, and ...

  19. 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.…

  20. Evaluation of chloride content in concrete by X-ray fluorescence

    Microsoft Academic Search

    Edoardo Proverbio; Fabio Carassiti

    1997-01-01

    Determination of chloride content in concrete structures can be carried out by the X-ray fluorescence technique. However some problems affect measurement validity and limit the convenience of using XRF analysis when a limited number of determinations have to be performed. Measurements carried out on chloride contaminated concrete and mixtures of NaCl and concrete show the influence of distribution and grain

  1. Analysis of tincal ore waste by energy dispersive X-ray fluorescence (EDXRF) Technique

    NASA Astrophysics Data System (ADS)

    Kalfa, Orhan Murat; Üstünda?, Zafer; Özk?r?m, Ilknur; Kagan Kad?o?lu, Yusuf

    2007-01-01

    Etibank Borax Plant is located in K?rka-Eski?ehir, Turkey. The borax waste from this plant was analyzed by means of energy dispersive X-ray fluorescence (EDXRF). The standard addition method was used for the determination of the concentration of Al, Fe, Zn, Sn, and Ba. The results are presented and discussed in this paper.

  2. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - FIELD PORTABLE X-RAY FLUORESCENCE ANALYZER - SCITEC, MAP SPECTRUM ANALYZER

    EPA Science Inventory

    In April 1995, the U.S. Environmental Protection Agency (EPA) sponsored a demonstration of field portable X-ray fluorescence (FPXRF) analyzers. The primary objectives of this demonstration were (1) to determine how well FPXRF analyzers perform in comparison to standard reference...

  3. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - FIELD PORTABLE X-RAY FLUORESCENCE ANALYZER - HNU SYSTEMS, SEFA-P

    EPA Science Inventory

    In April 1995, the Environmental Protection Agency (EPA) conducted a demonstration of field portable X-ray fluorescence (FPXRF) Analyzers. The primary objectives of this demonstration were (1) to determine how well FPXRF analyzers perform in comparison to a standard reference m...

  4. CHARACTERIZATION OF CHROMIUM-CONTAMINATED SOILS USING FIELD-PORTABLE X-RAY FLUORESCENCE

    EPA Science Inventory

    A detailed characterization of the underlying and adjacent soils near a chrome plating shop utilized field-portable X- ray fluorescence (XRF) as a screening tool. XRF permitted real-time acquisition of estimates for total metal content of soils. A trailer-mounted soil coring unit...

  5. The characterisation of a secondary fluorescence X-ray tube for medical imaging, security screening and analytical applications

    Microsoft Academic Search

    G. S. Dermody; T. Carter; I. D. Jupp; S. J. Hunter

    2000-01-01

    Describes the characterisation of a new prototype secondary fluorescence X-ray tube. This tube allows the user to interchange the secondary target, and thus select the X-ray tube spectrum. Measurements of the focal spot size, intensity the K? fluorescence lines and the spectral purity of the source are presented for a range of secondary targets including tantalum, tungsten, silver, copper and

  6. 2D imaging by X-ray fluorescence microtomography

    NASA Astrophysics Data System (ADS)

    Simionovici, A.; Chukalina, M.; Drakopoulos, M.; Snigireva, I.; Snigirev, A.; Schroer, Ch.; Lengeler, B.; Janssens, K.; Adams, F.

    2000-05-01

    First experimental results of fluorescence microtomography in "pencil-beam" geometry with 6 ?m resolution obtained at the ESRF/1D 22 are described. Image reconstructions are based on either a simplified algebraic reconstruction method (ART) or the filtered back-projection method (FBT). Simple cylindrical test objects are accurately reconstructed.

  7. X-ray fluorescence method for determining the thickness of an aluminum coating on steel

    Microsoft Academic Search

    N. I. Mashin; A. A. Leont’eva; A. N. Tumanova; A. A. Ershov

    2011-01-01

    We have used an EDX-720 energy-dispersive x-ray fluorescence spectrometer to develop a technique for determining the thickness\\u000a of an aluminum coating deposited on steel 47 NKhR. We have calculated the mass absorption coefficients for absorption of the\\u000a fluorescent emission of nickel by the aluminum coating, where nickel is a major component of the substrate material. We have\\u000a established and present

  8. A High-Speed Detector System for X-ray Fluorescence Microprobes.

    SciTech Connect

    Siddons,P.D.; Dragone, A.; De Geronimo, g.; Kuczewski, A.; Kuczewski, J.; O

    2006-10-29

    We have developed a high-speed system for collecting x-ray fluorescence microprobe data, based on ASICs developed at BNL and high-speed processors developed by CSIRO. The system can collect fluorescence data in a continuous raster scan mode, and present elemental images in real time using Ryan's Dynamic Analysis algorithm. We will present results from a 32-element prototype array illustrating the concept. The final instrument will have 384 elements arranged in a square array around a central hole.

  9. Demonstration of x-ray fluorescence imaging to diagnose high-energy-density plasmas

    NASA Astrophysics Data System (ADS)

    MacDonald, M. J.; Keiter, P. A.; Montgomery, D. S.; Biener, M. M.; Fein, J. R.; Fournier, K. B.; Gamboa, E. J.; Klein, S. R.; Kuranz, C. C.; Lefevre, H. J.; Manuel, M. J.-E.; Streit, J.; Wan, W. C.; Drake, R. P.

    2014-10-01

    X-ray diagnostic techniques are widely used to diagnose high-energy-density experiments. Radiography is used to create 2D images of plasma density using the relative transmission of the source x-rays, but the path-integrated nature of this process limits its usefulness when diagnosing large-volume or geometrically-complex targets. A technique capable of measuring local conditions is required to characterize plasmas in these geometries. Here we describe an x-ray fluorescence imaging (XRFI) diagnostic that uses a collimated probe beam to sample a small portion of the system. The x-ray fluorescence induced in the probed region was used to calculate material density, shock velocity, and temperature simultaneously using an imaging x-ray spectrometer. Data from recent experiments performed at the Trident laser facility at Los Alamos National Lab will be presented. This work is funded by the NNSA-DS and SC-OFES Joint Program in HED Laboratory Plasmas, Grant Number DE-NA0001840 and supported by the NSF GRFP Grant No. 2013155705.

  10. Novel wavelength-dispersive X-ray fluorescence spectrometer

    NASA Astrophysics Data System (ADS)

    Firsov, A.; Erko, A.; Senf, F.; Rehanek, J.; Brzhezinskaya, M.; Wernet, R. Mitzner Ph; Föhlisch, A.

    2013-03-01

    A new spectrometer, utilizing a reflection zone plate based grating, for the Mn L fluorescence line was recently designed, manufactured and tested at Helmholtz Zentrum Berlin. The angular acceptance of the grating is ~0.011 rad2 the absolute efficiency at 640 eV is 16%, and the energy resolution, for a detector slit size of 120 ?m and in simultaneous spectra registration mode, is about ?/?? ~ 100 FWHM.

  11. Atomic X-ray Spectra of Accretion Disk Atmospheres in the Kerr Metric

    SciTech Connect

    Jimenez-Garate, M A; Liedahl, D A; Mauche, C W; Raymond, J C

    2004-03-03

    We calculate the atmospheric structure of an accretion disk around a Kerr black hole and obtain its X-ray spectrum, which exhibits prominent atomic transitions under certain circumstances. The gravitational and Doppler (red)shifts of the C V, C VI, O VII, O VIII, and Fe I-XXVI emission lines are observable in active galaxies. We quantify the line emissivities as a function of radius, to identify the effects of atmospheric structure, and to determine the usefulness of these lines for probing the disk energetics. The line emissivities do not always scale linearly with the incident radiative energy, as in the case of Fe XXV and Fe XXVI. Our model incorporates photoionization and thermal balance for the plasma, the hydrostatic approximation perpendicular to the plane of the disk, and general relativistic tidal forces. We include radiative recombination rates, fluorescence yields, Compton scattering, and photoelectric opacities for the most abundant elements.

  12. Atomic X-Ray Spectra of Accretion Disk Atmospheres in the Kerr Metric

    E-print Network

    Mario A. Jimenez-Garate; Duane A. Liedahl; Christopher W. Mauche; John C. Raymond

    2004-04-02

    We calculate the atmospheric structure of an accretion disk around a Kerr black hole and obtain its X-ray spectrum, which exhibits prominent atomic transitions under certain circumstances. The gravitational and Doppler (red)shifts of the C V, C VI, O VII, O VIII, and Fe I-XXVI emission lines are observable in active galaxies. We quantify the line emissivities as a function of radius, to identify the effects of atmospheric structure, and to determine the usefulness of these lines for probing the disk energetics. The line emissivities do not always scale linearly with the incident radiative energy, as in the case of Fe XXV and Fe XXVI. Our model incorporates photoionization and thermal balance for the plasma, the hydrostatic approximation perpendicular to the plane of the disk, and general relativistic tidal forces. We include radiative recombination rates, fluorescence yields, Compton scattering, and photoelectric opacities for the most abundant elements.

  13. Surface extended x-ray absorption fine structure of low-Z absorbates using fluorescence detection

    SciTech Connect

    Stoehr, J.; Kollin, E.B.; Fischer, D.A.; Hastings, J.B.; Zaera, F.; Sette, F.

    1985-05-01

    Comparison of x-ray fluorescence yield (FY) and electron yield surface extended x-ray absorption fine structure spectra above the S K-edge for c(2 x 2) S on Ni(100) reveals an order of magnitude higher sensitivity of the FY technique. Using FY detection, thiophene (C/sub 4/H/sub 4/S) chemisorption on Ni(100) is studied with S coverages down to 0.08 monolayer. The molecule dissociates at temperatures as low as 100K by interaction with fourfold hollow Ni sites. Blocking of these sites by oxygen leaves the molecule intact.

  14. Quantitative analysis of single aerosol particles with confocal micro-X-ray fluorescence spectrometer

    NASA Astrophysics Data System (ADS)

    Sun, Tianxi; Liu, Zhiguo; Li, Yude; Lin, Xiaoyan; Wang, Guangfu; Zhu, Guanghua; Xu, Qing; Luo, Ping; Pan, Qiuli; Liu, Hui; Ding, Xunliang

    2010-10-01

    A laboratory confocal micro-X-ray fluorescence (XRF) spectrometer based on polycapillary X-ray optics (PXRO) was proposed to carry out the quantitative XRF analysis of single aerosol particles with smaller sizes than that of focal spot of the PXRO. The PXRO in the detection channel can both increase the collecting angle of the detector and lower the minimum detection limits of the XRF spectrometer. In order to reduce the effects of the PXRO on the analysis results, the sensitivities were corrected using a Gaussian function for the quantitative XRF analysis of single aerosol particles.

  15. SAVLOC, computer program for automatic control and analysis of X-ray fluorescence experiments

    NASA Technical Reports Server (NTRS)

    Leonard, R. F.

    1977-01-01

    A program for a PDP-15 computer is presented which provides for control and analysis of trace element determinations by using X-ray fluorescence. The program simultaneously handles data accumulation for one sample and analysis of data from previous samples. Data accumulation consists of sample changing, timing, and data storage. Analysis requires the locating of peaks in X-ray spectra, determination of intensities of peaks, identification of origins of peaks, and determination of a real density of the element responsible for each peak. The program may be run in either a manual (supervised) mode or an automatic (unsupervised) mode.

  16. Combined X-ray Microfluorescence and Atomic Force Microscopy Studies of Mg Distribution in Whole Cells

    SciTech Connect

    Lagomarsino, S. [IPCF-CNR, UOS Roma, c/o Dip. di Fisica, Universita 'Sapienza', Piazzale Aldo Moro, 2 - 00185 Roma (Italy); Iotti, S. [Dipartimento di Medicina Interna, dell'Invecchiamento e Malattie Nefrologiche Universita di Bologna, Via Massarenti, 9 40138 Bologna (Italy); Farruggia, G. [Dipartimento di Biochimica 'G. Moruzzi' Universita di Bologna, Via Irnerio, 48 40126 Bologna (Italy); Trapani, V.; Mastrototaro, L.; Wolf, F. [Istituto di Patologia Generale - Universita Cattolica del Sacro Cuore - Facolta di Medicina 'A. Gemelli' L.go F. Vito, 1 00168 Rome (Italy); Cedola, A.; Fratini, M.; Notargiacomo, A. [IFN-CNR - UOS Roma, V. Cineto Romano, 42 00156 Rome (Italy); Bukreeva, I. [IFN-CNR - UOS Roma, V. Cineto Romano, 42 00156 Rome (Italy); Russian Academy of Science, P. N. Lebedev Physics Institute, Leninsky pr. 53, 119991 Moscow (Russian Federation); McNulty, I.; Vogt, S.; Kim, S.; Legnini, D. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Maier, J. A. M. [Dipartimento di Scienze Cliniche, Universita di Milano, Via GB Grassi 74, 20157 Milan (Italy)

    2011-09-09

    We present in this paper a novel methodology that combines scanning x-ray fluorescencee microscopy and atomic force microscopy. The combination of these two techniques allows the determination of a concentration map of Mg in whole (not sectioned) cells.

  17. Femtosecond electronic response of atoms to ultra-intense x-rays.

    SciTech Connect

    Young, L.; Kanter, E .P.; Li, Y.; March, A.-M.; Pratt, S. T.; Santra, R.; Southworth, S. H.; Rohringer, N.; DiMauro, L. F.; Doumy, G.; Roedig, C. A.; Berrah, N.; Fang, L.; Hoener, M.; Bucksbaum, P. H.; Cryan, J. P .; Ghimire, S.; Glownia, J. M.; Reis, D. A.; Bozek, J. D.; Bostedt, C.; Messerschmidt, M.; Western Michigan Univ.; SLAC National Accelerator Lab.; The Ohio State Univ.; LLNL; Univ. of Chicago

    2010-07-01

    An era of exploring the interactions of high-intensity, hard X-rays with matter has begun with the start-up of a hard-X-ray free-electron laser, the Linac Coherent Light Source (LCLS). Understanding how electrons in matter respond to ultra-intense X-ray radiation is essential for all applications. Here we reveal the nature of the electronic response in a free atom to unprecedented high-intensity, short-wavelength, high-fluence radiation (respectively 10{sup 18} W cm{sup -2}, 1.5-0.6 nm, {approx}10{sup 5} X-ray photons per {angstrom}{sup 2}). At this fluence, the neon target inevitably changes during the course of a single femtosecond-duration X-ray pulse - by sequentially ejecting electrons - to produce fully-stripped neon through absorption of six photons. Rapid photoejection of inner-shell electrons produces 'hollow' atoms and an intensity-induced X-ray transparency. Such transparency, due to the presence of inner-shell vacancies, can be induced in all atomic, molecular and condensed matter systems at high intensity. Quantitative comparison with theory allows us to extract LCLS fluence and pulse duration. Our successful modelling of X-ray/atom interactions using a straightforward rate equation approach augurs favourably for extension to complex systems.

  18. Atomic structure of nickel phthalocyanine probed by X-ray absorption spectroscopy and density functional simulations

    NASA Astrophysics Data System (ADS)

    Avakyan, L. A.; Manukyan, A. S.; Mirzakhanyan, A. A.; Sharoyan, E. G.; Zubavichus, Y. V.; Trigub, A. L.; Kolpacheva, N. A.; Bugaev, L. A.

    2013-03-01

    The local atomic structure of Ni in nickel phthalocyanine was studied by K-edge X-ray absorption fine structure spectroscopy. The obtained inter atomic nickel-nitrogen distance differs from the reference X-ray diffraction data so an additional study was performed within density functional theory framework. The justification of the used theoretical approach was provided by a comparison of theoretical free electron densities of states with experimental Ni K-edge X-ray absorption near edge spectra. The refined Ni local environment retain the reference structure of the molecule except for the length of Ni-N bond which increases to 1.90 Å.

  19. Correction method for self-absorption effects of fluorescence x-ray absorption near-edge structure on multilayer samples

    NASA Astrophysics Data System (ADS)

    Li, Wen-bin; Yuan, Xiao-feng; Zhu, Jing-tao; Zhu, Jie; Wang, Zhan-shan

    2015-01-01

    It is well known that fluorescence x-ray absorption spectroscopy suffers from the self-absorption effects for thick and concentrated samples. In this study, a simple correction method is provided for correcting the self-absorption effects of fluorescence x-ray absorption near edge structure (XANES) spectrum for multilayer samples. This method is validated by application on fluorescence XANES spectra for a Cr/C multilayer measured at different incidence angles. The errors produced by the self-absorption effects for the measured fluorescence x-ray absorption spectra without corrections are also estimated and discussed.

  20. X-ray fluorescence microtomography: experiment and reconstruction

    NASA Astrophysics Data System (ADS)

    Simionovici, Alexandre S.; Chukalina, Marina; Drakopoulos, Michael; Snigireva, Irina; Snigirev, Anatoly A.; Schroer, Christian G.; Lengeler, Bruno; Janssens, Koen; Adams, Freddy

    1999-09-01

    First experimental results of fluorescence microtomography with 6 micrometer resolution obtained at the ESRF are described. The set-up comprises high quality optics (monochromator, mirrors, focusing lenses) coupled to the high energy/brilliance/coherence of the ID 22 undulator beamline. The tomographic set-up allows precise measurements in the 'pencil-beam' geometry. The image reconstruction is based either on the filtered back-projection (FBT) method or on a modification of the algebraic reconstruction method (ART) but includes simplifications of the model. The quality and precision of the 2D reconstructed elemental images of two phantom sample are encouraging. The method will be further refined and applied for the analysis of more complex inhomogeneous samples.

  1. Improvement of total reflection X-ray fluorescence spectrometer sensitivity by flowing nitrogen gas

    NASA Astrophysics Data System (ADS)

    Imashuku, Susumu; Tee, Deh Ping; Kawai, Jun

    2012-07-01

    The intensity of Ar K? line was reduced by a factor of 17 times by flowing more than 400 mL min- 1 of N2 gas through gas pipe placed at the gap between the X-ray detector and the sample stage of the total reflection X-ray fluorescence (TXRF) spectrometer. The signal-to-background ratios of characteristic X-rays with energies less than 8 keV were improved by flowing N2 gas owing to the reduction of peak pileups related to the Ar K? peak. The improvement of the signal-to-background ratios became significant as the energies of the characteristic X-rays approached that of the Ar K? line (2.96 keV) for characteristic X-rays with energies less than 5 keV. When 1 ?L of solution containing 10 mg L- 1 cadmium (10 ng) was measured with the TXRF spectrometer by flowing N2 gas, Cd L? line was clearly observed, although the Cd L? line overlapped with the Ar K lines without flowing N2 gas. The lower limit of detection of cadmium evaluated from the Cd L? line was improved from 7.0 to 2.2 ng by flowing N2 gas. This N2 gas flowing technique can be applied to trace element analysis of cadmium in solutions which do not contain potassium such as leaching solutions from products containing cadmium in TXRF and conventional XRF measurements.

  2. Total reflection X-ray fluorescence and energy-dispersive X-ray fluorescence analysis of runoff water and vegetation from abandoned mining of Pb Zn ores

    NASA Astrophysics Data System (ADS)

    Marques, A. F.; Queralt, I.; Carvalho, M. L.; Bordalo, M.

    2003-12-01

    The present work reports on the heavy metal content: Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd and Pb in running waters and vegetation around abandoned mining areas. Two species of mosses ( Dicranum sp. and Pleurocarpus sp.) and three different species of wild grass ( Bromus sp., Rumex sp. and Pseudoavena sp.) growing on the surrounding areas of old lead-zinc mines (Aran Valley, Pyrenees, NE Spain) have been analyzed. Both water and vegetation were collected in two different sampling places: (a) near the mine gallery water outlets and (b) on the landfill close to the abandoned mineral concentration factories. For the heavy metal content determination, two different techniques were used: total reflection X-ray fluorescence for water analysis and energy-dispersive X-ray fluorescence for vegetation study. Surface waters around mine outlets exhibit anomalous content of Co, Ni, Zn, Cd. Stream waters running on mining landfills exhibit higher Cu, Zn, Cd and Pb than those of the waters at the mine gallery outlets. The results allow us to assess the extent of the environmental impact of the mining activities on the water quality. The intake of these elements by vegetation was related with the sampling place, reflecting the metal water content and the substrate chemistry. Accumulation of metals in mosses is higher than those exhibited in wild grasses. Furthermore, different levels of accumulation were found in different wild grass. Rumex sp. presented the lowest metal concentrations, while Pseudoavena sp. reported the highest metal content.

  3. Computed tomography and X-ray fluorescence CT of biological samples

    NASA Astrophysics Data System (ADS)

    Pereira, G. R.; Anjos, M. J.; Rocha, H. S.; Faria, P.; Pérez, C. A.; Lopes, R. T.

    2007-10-01

    Transmission microtomography ( ?CT) and X-ray fluorescence microtomography (XRF ?CT) are complementary and noninvasive techniques used for sample characterization. ?CT provide information on the attenuation coefficients, while XRF ?CT can provide the distribution of all elements in a sample. XRF ?CT is a noninvasive technique, based on the detection of X-ray fluorescence emitted by the elements in the sample, and it is used to complement other techniques for sample characterization. The experiments were performed at the X-Ray Fluorescence (XRF) beamline of the Brazilian Synchrotron Light Laboratory (LNLS), Campinas, Brazil. A monochromatic beam of 9.8 keV was used for excitation of the elements within samples and the fluorescence photons were detected by an HPGe detector. The incident beam was monitored by an ionization chamber and a fast scintillator detector was used to detect the transmitted radiation. In this work, several intestine and breast tissue samples were investigated in order to verify the concentration of some elements correlated with the characteristics and pathology of each tissue observed by transmission ?CT. All XRF ?CT were reconstructed using a filtered back-projection algorithm. In those samples the elements Zn, Cu, and Fe were observed.

  4. Bent Laue X-ray Fluorescence Imaging of Manganese in Biological Tissues--Preliminary Results

    SciTech Connect

    Zhu Ying; Zhang Honglin [Biomedical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9 (Canada); Bewer, Brian [Physics and Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon, SK S7N 5E2 (Canada); Nichol, Helen; Chapman, Dean [Anatomy and Cell Biology, University of Saskatchewan, 107 Wiggins Road, Saskatoon, SK S7N 5E5 (Canada); Thomlinson, Bill [Office of the Vice President Research, University of Saskatchewan, 121 Research Drive, Saskatoon, SK S7N 1K2 (Canada)

    2010-06-23

    Manganese (Mn) is not abundant in human brain tissue, but it is recognized as a neurotoxin. The symptoms of manganese intoxication are similar to Parkinson's disease (PD), but the link between environmental, occupational or dietary Mn exposure and PD in humans is not well established. X-ray Absorption Spectroscopy (XAS) and in particular X-ray fluorescence can provide precise information on the distribution, concentration and chemical form of metals. However the scattered radiation and fluorescence from the adjacent abundant element, iron (Fe), may interfere with and limit the ability to detect ultra-dilute Mn. A bent Laue analyzer based Mn fluorescence detection system has been designed and fabricated to improve elemental specificity in XAS imaging. This bent Laue analyzer of logarithmic spiral shape placed upstream of an energy discriminating detector should improve the energy resolution from hundreds of eV to several eV. The bent Laue detection system was validated by imaging Mn fluorescence from Mn foils, gelatin calibration samples and adult Drosophila at the Hard X-ray MicroAnalysis (HXMA) beamline at the Canadian Light Source (CLS). Optimization of the design parameters, fabrication procedures and preliminary experimental results are presented along with future plans.

  5. Confocal micro-x-ray fluorescence spectrometer for light element analysis

    NASA Astrophysics Data System (ADS)

    Smolek, S.; Pemmer, B.; Fölser, M.; Streli, C.; Wobrauschek, P.

    2012-08-01

    An existing micro-x-ray fluorescence (micro-XRF) spectrometer designed for light element analysis (6 ? Z ? 14) has been extended to confocal geometry: a second polycapillary x-ray optic has been introduced in front of the energy dispersive x-ray detector. New piezo positioners for optimum alignment of both optics have been installed inside the vacuum chamber. The spectrometer offers now the possibility of true 3D elemental analysis in the micrometer regime. Depth resolution varies between 100 ?m at 1 keV fluorescence energy (Na-K?) and 30 ?m for 17.5 keV (Mo). To further extend analytical capabilities a second x-ray tube with a Rh anode has been acquired to supplement to existing Mo anode tube. Lower limits of detection have been determined to be in the ppm region for confocal geometry. The spectrometer has been characterized and tested using different samples. Furthermore, results have been compared with SR micro-XRF to show the capabilities and limitations of this spectrometer.

  6. In-situ speciation of arsenic contaminated soil using micro-focused x-ray fluorescence and x-ray absorption fine

    E-print Network

    Sparks, Donald L.

    In-situ speciation of arsenic contaminated soil using micro-focused x-ray fluorescence and x-A, 0-20 cm; LM-B, 20-40 cm) of a mixed metal-arsenic contaminated soil from a former copper chromated, 2003, 1:55 PM-5:20 PM Presentation Start: 3:15 PM Keywords: soil contamination; arsenic speciation

  7. ENVIRONMENTAL TECHNOLOGY VERFICATION REPORT - FIELD PORTABLE X-RAY FLUORESCENCE ANALYZER - TN SPECTRACE, TN 9000 AND TN PB FIELD PORTABLE X-RAY FLOURESCENCE ANALYZERS

    EPA Science Inventory

    In April 1995, the U.S. Environmental Protection Agency (EPA) sponsored a demonstration of field portable X-ray fluorescence (FPXRF) analyzers. The primary objectives of this demonstration were to evaluate these analyzers for: (1) their analytical performance relative to standar...

  8. New Directions in X-Ray Light Sources or Fiat Lux: what's under the dome and watching atoms with x-rays (LBNL Summer Lecture Series)

    ScienceCinema

    Falcone, Roger

    2011-04-28

    Summer Lecture Series 2008: Molecular movies of chemical reactions and material phase transformations need a strobe of x-rays, the penetrating light that reveals how atoms and molecules assemble in chemical and biological systems and complex materials. Roger Falcone, Director of the Advanced Light Source,will discuss a new generation of x ray sources that will enable a new science of atomic dynamics on ultrafast timescales.

  9. New Directions in X-Ray Light Sources or Fiat Lux: what's under the dome and watching atoms with x-rays (LBNL Summer Lecture Series)

    SciTech Connect

    Falcone, Roger

    2008-07-15

    Summer Lecture Series 2008: Molecular movies of chemical reactions and material phase transformations need a strobe of x-rays, the penetrating light that reveals how atoms and molecules assemble in chemical and biological systems and complex materials. Roger Falcone, Director of the Advanced Light Source,will discuss a new generation of x ray sources that will enable a new science of atomic dynamics on ultrafast timescales.

  10. Application of the Total Reflection X-ray Fluorescence technique to trace elements determination in tobacco

    NASA Astrophysics Data System (ADS)

    Martinez, T.; Lartigue, J.; Zarazua, G.; Avila-Perez, P.; Navarrete, M.; Tejeda, S.

    2008-12-01

    Many studies have identified an important number of toxic elements along with organic carcinogen molecules and radioactive isotopes in tobacco. In this work we have analyzed by Total Reflection X-Ray Fluorescence 9 brands of cigarettes being manufactured and distributed in the Mexican market. Two National Institute of Standards and Technology standards and a blank were equally treated at the same time. Results show the presence of some toxic elements such as Pb and Ni. These results are compared with available data for some foreign brands, while their implications for health are discussed. It can be confirmed that the Total Reflection X-Ray Fluorescence method provides precise (reproducible) and accuracy (trueness) data for 15 elements concentration in tobacco samples.

  11. X-ray Fluorescence Emission Tomography (XFET) with Novel Imaging Geometries – A Monte Carlo Study

    PubMed Central

    Meng, L. J.; Li, Nan; La Riviere, P. J.

    2011-01-01

    This paper presents a feasibility study for using two new imaging geometries for synchrotron X-ray fluorescence emission tomography (XFET) applications. In the proposed approaches, the object is illuminated with synchrotron X-ray beams of various cross-sectional dimensions. The resultant fluorescence photons are detected by high-resolution imaging-spectrometers coupled to collimation apertures. To verify the performance benefits of the proposed methods over the conventional line-by-line scanning approach, we have used both Monte Carlo simulations and an analytical system performance index to compare several different imaging geometries. This study has demonstrated that the proposed XFET approach could lead to a greatly improved imaging speed, which is critical for making XFET a practical imaging modality for a wide range of applications. PMID:22228913

  12. Determination of catalyst metal residues in polymers by X-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Bichinho, Kátia M.; Pires, Gilvan Pozzobon; Stedile, Fernanda C.; dos Santos, João Henrique Z.; Wolf, Carlos Rodolfo

    2005-06-01

    Commercial polyethylenes produced by Ziegler-Natta, Philips and metallocene technology were analyzed by X-ray fluorescence spectroscopy. Synthetic standards using wax matrix was shown to be suitable for the calibration curve in comparison to those prepared by milling and grinding virgin polymer mixed with standard metal oxide as matrix. The detection limits obtained for the studied metal in the different polymers were: 12 mg kg -1 for Mg, 0.8 mg kg -1 for Ti, 1.6 mg kg -1 for Cr, 1.2 mg kg -1 for Zr and 1.9 mg kg -1 for V. For comparative reasons, the determination of residual metal content by Rutherford backscattering spectrometry (RBS) and total-reflection X-ray fluorescence spectrometry (TXRF) is also discussed.

  13. Hydrogen atoms in protein structures: high-resolution X-ray diffraction structure of the DFPase

    PubMed Central

    2013-01-01

    Background Hydrogen atoms represent about half of the total number of atoms in proteins and are often involved in substrate recognition and catalysis. Unfortunately, X-ray protein crystallography at usual resolution fails to access directly their positioning, mainly because light atoms display weak contributions to diffraction. However, sub-Ångstrom diffraction data, careful modeling and a proper refinement strategy can allow the positioning of a significant part of hydrogen atoms. Results A comprehensive study on the X-ray structure of the diisopropyl-fluorophosphatase (DFPase) was performed, and the hydrogen atoms were modeled, including those of solvent molecules. This model was compared to the available neutron structure of DFPase, and differences in the protein and the active site solvation were noticed. Conclusions A further examination of the DFPase X-ray structure provides substantial evidence about the presence of an activated water molecule that may constitute an interesting piece of information as regard to the enzymatic hydrolysis mechanism. PMID:23915572

  14. An elemental correlation study in cancerous breast tissue by total reflection x-ray fluorescence

    Microsoft Academic Search

    Urszula Majewska; Janusz Braziewicz; Dariusz Bana?; Aldona Kubala-Kuku?; Stanis?aw Gó?d?; Marek Pajek; Jolanta Smok; Antoinette CJrbaniak

    1997-01-01

    The total reflection x-ray fluorescence method (TRXRF) has been employed to determine of P, S, K, Ca, Cr, Mn, Fe, Ni, Cu,\\u000a Zn, Se, Rb, Sr, and Pb concentration in the benign breast tumor tissue from 68 women and in the cancerous breast tissue from\\u000a 26 women. Concentrations of most of elements show enhancement in cancerous breast tissue. Examined elements

  15. Applications of total reflection X-ray fluorescence to analysis of VLSI micro contamination

    Microsoft Academic Search

    Bor Wen Liou; Chung Len Lee

    1999-01-01

    This paper demonstrates the microcontamination analysis on wafers after they have been through the conventional ULSI processing steps, by using the vapor phase decomposition\\/total reflection X-ray fluorescence (VPD\\/TXRF) technique. It was found that the wafer location in the holding cassette during the chemical cleaning step affected the cleanness of the wafer, and the class 1 environment was not enough to

  16. Electrodeposition as a sample preparation technique for total-reflection X-ray fluorescence analysis

    Microsoft Academic Search

    Simone Griesel; Ulrich Reus; Andreas Prange

    2001-01-01

    A one-step sample preparation by electro-deposition for total-reflection X-ray fluorescence (TXRF) analysis has been developed using a common three-electrode arrangement with a rotating disc as the working electrode. Several elements such as Cr, Mn, Fe, Co, Ni, Cu, Zn, Ag, Cd, Pb, As and U have been determined simultaneously in saline matrix. A special electrode tip has been constructed as

  17. Forensic application of total reflection X-ray fluorescence spectrometry for elemental characterization of ink samples

    Microsoft Academic Search

    Sangita Dhara; N. L. Misra; S. D. Maind; Sanjukta A. Kumar; N. Chattopadhyay; S. K. Aggarwal

    2010-01-01

    The possibility of applying Total Reflection X-ray Fluorescence for qualitative and quantitative differentiation of documents printed with rare earth tagged and untagged inks has been explored in this paper. For qualitative differentiation, a very small amount of ink was loosened from the printed documents by smoothly rubbing with a new clean blade without destroying the manuscript. 50?L of Milli-Q water

  18. Characterization of phosphorus in organisms at sub-micron resolution using X-ray fluorescence spectromicroscopy.

    SciTech Connect

    Diaz, J.; Ingall, E; Vogt, S; Paterson, D; DeJonge, M; Rao, C; Brandes, J

    2009-01-01

    X-ray spectromicroscopy (combined X-ray spectroscopy and microscopy) is uniquely capable of determining sub-micron scale elemental content and chemical speciation in minimally-prepared particulate samples. The high spatial resolutions achievable with this technique have enabled the close examination of important microscale processes relevant to the cycling of biogeochemically important elements. Here, we demonstrate the value of X-ray microscopy to environmental and biological research by examining the phosphorus and metal chemistry of complete individual cells from the algal genera Chlamydomonas sp. and Chlorella sp. X-ray analysis revealed that both genera store substantial intracellular phosphorus as distinct, heterogeneously distributed granules whose X-ray fluorescence spectra are consistent with that of polyphosphate. Polyphosphate inclusions ranged in size from 0.3-1.4 {micro}m in diameter and exhibited a nonspecies-specific average phosphorus concentration of 6.87 {+-} 1.86 {micro}g cm{sup -2}, which was significantly higher than the average concentration of phosphorus measured in the total cell, at 3.14 {+-} 0.98 {micro}g cm{sup -2} (95% confidence). Polyphosphate was consistently associated with calcium and iron, exhibiting average P:cation molar ratios of 8.31 {+-} 2.00 and 108 {+-} 34, respectively (95% confidence). In some cells, polyphosphate was also associated with potassium, zinc, manganese, and titanium. Based on our results, X-ray spectromicroscopy can provide high-resolution elemental data on minimally prepared, unsectioned cells that are unattainable through alternative microscopic methods and conventional bulk chemical techniques currently available in many fields of marine chemistry.

  19. The use of swept-charge devices in planetary analogue X-ray fluorescence studies

    NASA Astrophysics Data System (ADS)

    Walker, T. E.; Smith, D. R.

    2012-07-01

    The Chandrayaan-1 X-ray Spectrometer (C1XS) was launched onboard the Indian Space Research Organisation (ISRO) Chandrayaan-1 lunar mission in October 2008. The instrument consisted of 24 swept-charge device (SCD) silicon X-ray detectors providing a total collecting area of ~ 24 cm2, corresponding to a 14° field of view (FWHM), with the ability to measure X-rays from 0.8-10 keV. One algorithm used to analyse the C1XS flight data was developed at Rutherford Appleton Laboratory (RAL) to convert the raw X-ray flux data into elemental ratios and abundances to make geological interpretations about the lunar surface. Laboratory X-ray fluorescence (XRF) data were used to validate the RAL algorithm, with previous studies investigating how the measured XRF flux varies with target surface characteristics including grain size and roughness. Evidence for a grain-size effect was observed in the data, the XRF line intensity generally decreasing with increasing sample grain size, dependent on the relative abundance of elemental components. This paper presents a subsequent study using more homogeneous samples made from mixtures of MgO, Al2O3 and SiO2 powders, all of grain size < 44 ?m, across a broader range of mixture ratios and at a higher level of X-ray flux data in order to further validate the RAL algorithm. For the majority of the C1XS flight data analysed so far with the RAL algorithm, the corresponding lunar ground tracks have been generally basaltic, laboratory verification of the algorithm having been primarily conducted using basaltic lunar regolith simulant (JSC-1A) XRF data. This paper also presents results from tests on a terrestrial anorthosite sample, more relevant to the anorthositic lunar highlands, from where the remaining C1XS lunar dataset derives. The operation of the SCD, the XRF test facility, sample preparation and collected XRF spectra are discussed in this paper.

  20. Variable X-ray excitation for total reflection X-ray fluorescence spectrometry using an Mo/W alloy anode and a tunable double multilayer monochromator

    NASA Astrophysics Data System (ADS)

    Knoth, J.; Prange, A.; Schneider, H.; Schwenke, H.

    1997-07-01

    A new total reflection X-ray fluorescence spectrometer has been developed which uses a variable double multilayer arrangement as a tunable monochromator together with an X-ray fine structure tube which is characterized by an anode made of a homogeneous alloy of molybdenum and tungsten. Three discretely adjustable excitation energies, namely 9.7 keV, 17.5 keV and 35 keV, are supplied by this combination. The detection limits were determined to be 0.4 pg nickel using W L? excitation, 0.6 pg lead using Mo K? excitation and 8 pg cadmium using 35 keV bandpass excitation.

  1. Determination of fluorine by total reflection X-ray fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Tarsoly, G.; Óvári, M.; Záray, Gy.

    2010-04-01

    There is a growing interest in determination of low Z elements, i.e. carbon to phosphorus, in various samples. Total reflection X-ray fluorescence spectrometry (TXRF) has been already established as a suitable trace element analytical method with low sample demand and quite good quantification limits. Recently, the determinable element range was extended towards Z = 6 (carbon). In this study, the analytical performance of the total reflection X-ray fluorescence spectrometry for determination of fluorine was investigated applying a spectrometer equipped with Cr-anode X-ray tube, multilayer monochromator, vacuum chamber, and a silicon drift detector (SDD) with ultra thin window was used. The detection limit for fluorine was found to be 5 mg L - 1 (equivalent to 10 ng absolute) in aqueous matrix. The linear range of the fluorine determination is between 15 and 500 mg L - 1 , within this range the precision is below 10%. The matrix effects of the other halogens (chlorine, bromine and iodine), and sulfate were also investigated. It has been established that the upper allowed concentration limit of the above interfering elements is 100, 200, 50 and 100 mg L - 1 for Cl, Br, I and sulfate, respectively. Moreover, the role of the pre-siliconization of the quartz carrier plate was investigated. It was found, that the presence of the silicone results in poorer analytical performance, which can be explained by the thicker sample residue and stronger self-absorption of the fluorescent radiation.

  2. In vivo X-ray fluorescence of lead in bone: review and current issues.

    PubMed Central

    Todd, A C; Chettle, D R

    1994-01-01

    Bone lead measurements can assess long-term lead dosimetry because the residence time of lead in bone is long. Bone lead measurements thus complement blood and plasma lead measurements, which reflect more short-term exposure. Although the noninvasive, in vivo measurement of lead in bone by X-ray fluorescence (XRF) has been under development since the 1970s, its use is still largely confined to research institutions. There are three principal methods used that vary both in the how lead X-rays are fluoresced and in which lead X-rays are fluoresced. Several groups have reported the independent development of in vivo measurement systems, the majority adopting the 109Cd K XRF method because of its advantages: a robust measurement, a lower detection limit (compared to 57Co K XRF), and a lower effective (radiation) dose (compared to L XRF) when calculated according to the most recent guidelines. These advantages, and the subsequent widespread adoption of the 109Cd method, are primarily consequences of the physics principles of the technique. This paper presents an explanation of the principles of XRF, a description of the practical measurement systems, a review of the human bone lead studies performed to date; and a discussion of some issues surrounding future application of the methods. Images p172-a PMID:8033846

  3. X-Ray Microprobe of Orbital Alignment in Strong-Field Ionized Atoms

    Microsoft Academic Search

    L. Young; D. A. Arms; E. M. Dufresne; R. W. Dunford; D. L. Ederer; C. Höhr; E. P. Kanter; B. Krässig; E. C. Landahl; E. R. Peterson; J. Rudati; R. Santra; S. H. Southworth

    2006-01-01

    We have developed a synchrotron-based, time-resolved x-ray microprobe to investigate optical strong-field processes at intermediate intensities (1014 1015W\\/cm2). This quantum-state specific probe has enabled the direct observation of orbital alignment in the residual ion produced by strong-field ionization of krypton atoms via resonant, polarized x-ray absorption. We found strong alignment to persist for a period long compared to the spin-orbit

  4. Sub-atomic resolution X-ray crystallography and neutron crystallography: promise, challenges and potential

    PubMed Central

    Blakeley, Matthew P.; Hasnain, Samar S.; Antonyuk, Svetlana V.

    2015-01-01

    The International Year of Crystallography saw the number of macromolecular structures deposited in the Protein Data Bank cross the 100000 mark, with more than 90000 of these provided by X-ray crystallography. The number of X-ray structures determined to sub-atomic resolution (i.e. ?1?Å) has passed 600 and this is likely to continue to grow rapidly with diffraction-limited synchrotron radiation sources such as MAX-IV (Sweden) and Sirius (Brazil) under construction. A dozen X-ray structures have been deposited to ultra-high resolution (i.e. ?0.7?Å), for which precise electron density can be exploited to obtain charge density and provide information on the bonding character of catalytic or electron transfer sites. Although the development of neutron macromolecular crystallography over the years has been far less pronounced, and its application much less widespread, the availability of new and improved instrumentation, combined with dedicated deuteration facilities, are beginning to transform the field. Of the 83 macromolecular structures deposited with neutron diffraction data, more than half (49/83, 59%) were released since 2010. Sub-mm3 crystals are now regularly being used for data collection, structures have been determined to atomic resolution for a few small proteins, and much larger unit-cell systems (cell edges >100?Å) are being successfully studied. While some details relating to H-atom positions are tractable with X-ray crystallography at sub-atomic resolution, the mobility of certain H atoms precludes them from being located. In addition, highly polarized H atoms and protons (H+) remain invisible with X-rays. Moreover, the majority of X-ray structures are determined from cryo-cooled crystals at 100?K, and, although radiation damage can be strongly controlled, especially since the advent of shutterless fast detectors, and by using limited doses and crystal translation at micro-focus beams, radiation damage can still take place. Neutron crystallography therefore remains the only approach where diffraction data can be collected at room temperature without radiation damage issues and the only approach to locate mobile or highly polarized H atoms and protons. Here a review of the current status of sub-atomic X-ray and neutron macromolecular crystallography is given and future prospects for combined approaches are outlined. New results from two metalloproteins, copper nitrite reductase and cytochrome c?, are also included, which illustrate the type of information that can be obtained from sub-atomic-resolution (?0.8?Å) X-ray structures, while also highlighting the need for complementary neutron studies that can provide details of H atoms not provided by X-ray crystallography. PMID:26175905

  5. A dosimetry study for a K-fluorescent x-ray system 

    E-print Network

    Beard, Travis Newton

    1975-01-01

    -fluorescent beam. K-fluorescence radiation is based on one of the fundamentals of nuclear physics ? the photoelectric effect (Compton, 1929). In this process the incident quantum of radiation interacts with an electron in one of the inner shells (usually K or L... Subject: Nuclear Engineering (Health Physics) A DOSIMETRY STUDY FOR A K-FI. UORESCENT X-RAY SYSTEM A Thesis by TRAVIS NEWTON BEARD Approved as to style and conte t by: f / C. ' (Ch~airman of Comm( t ) I I (Head of Department) Me5 (Member...

  6. The first microbeam synchrotron X-ray fluorescence beamline at the Siam Photon Laboratory.

    PubMed

    Tancharakorn, Somchai; Tanthanuch, Waraporn; Kamonsutthipaijit, Nuntaporn; Wongprachanukul, Narupon; Sophon, Methee; Chaichuay, Sarunyu; Uthaisar, Chunmanus; Yimnirun, Rattikorn

    2012-07-01

    The first microbeam synchrotron X-ray fluorescence (µ-SXRF) beamline using continuous synchrotron radiation from Siam Photon Source has been constructed and commissioned as of August 2011. Utilizing an X-ray capillary half-lens allows synchrotron radiation from a 1.4?T bending magnet of the 1.2?GeV electron storage ring to be focused from a few millimeters-sized beam to a micrometer-sized beam. This beamline was originally designed for deep X-ray lithography (DXL) and was one of the first two operational beamlines at this facility. A modification has been carried out to the beamline in order to additionally enable µ-SXRF and synchrotron X-ray powder diffraction (SXPD). Modifications included the installation of a new chamber housing a Si(111) crystal to extract 8?keV synchrotron radiation from the white X-ray beam (for SXPD), a fixed aperture and three gate valves. Two end-stations incorporating optics and detectors for µ-SXRF and SXPD have then been installed immediately upstream of the DXL station, with the three techniques sharing available beam time. The µ-SXRF station utilizes a polycapillary half-lens for X-ray focusing. This optic focuses X-ray white beam from 5?mm × 2?mm (H × V) at the entrance of the lens down to a diameter of 100?µm FWHM measured at a sample position 22?mm (lens focal point) downstream of the lens exit. The end-station also incorporates an XYZ motorized sample holder with 25?mm travel per axis, a 5× ZEISS microscope objective with 5?mm × 5?mm field of view coupled to a CCD camera looking to the sample, and an AMPTEK single-element Si (PIN) solid-state detector for fluorescence detection. A graphic user interface data acquisition program using the LabVIEW platform has also been developed in-house to generate a series of single-column data which are compatible with available XRF data-processing software. Finally, to test the performance of the µ-SXRF beamline, an elemental surface profile has been obtained for a piece of ancient pottery from the Ban Chiang archaeological site, a UNESCO heritage site. It was found that the newly constructed µ-SXRF technique was able to clearly distinguish the distribution of different elements on the specimen. PMID:22713886

  7. X-ray fluorescence analysis of cultural artefacts — Applications to the Czech heritage

    NASA Astrophysics Data System (ADS)

    Trojek, T.; Musílek, L.; ?echák, T.

    2014-02-01

    X-ray florescence analysis is an excellent non-destructive tool for analysing the elemental composition of materials in a wide range of works of art. The Department of Dosimetry and Application of Ionising Radiation at CTU-FNSPE has used radionuclide or X-ray tube excited energy dispersive X-ray fluorescence for many kinds of artefacts, including frescos, paintings, manuscripts, metal sculptures and other objects, ceramics, jewellery, various archaeological finds, etc. The method used is more or less "traditional", i.e., semiconductor spectrometry of excited X-rays, with some optional choices—capillary optics for collimation of exciting beams and two-dimensional scanning. The "hardware" complex is supplemented by techniques for estimating the depth distribution of measured elements, for suppressing surface effects, for in situ non-contact measurements, etc. Extending the measurable range to lighter elements and decreasing the detection limits is one of the achievements that has been attained by improving the instrumentation and techniques that are used. This paper gives a brief review of works carried out at the Department of Dosimetry and Application of Ionising Radiation at CTU-FNSPE.

  8. Handheld X-ray Fluorescence Spectrometers: Radiation Exposure Risks of Matrix-Specific Measurement Scenarios.

    PubMed

    Rouillon, Marek; Kristensen, Louise J; Gore, Damian B

    2015-07-01

    This study investigates X-ray intensity and dispersion around handheld X-ray fluorescence (XRF) instruments during the measurement of a range of sample matrices to establish radiation exposure risk during operation. Four handheld XRF instruments representing three manufacturers were used on four smooth, flat-lying materials of contrasting matrix composition. Dose rates were measured at 10, 20, 30, and 40 cm intervals every 30° around the instrument at 0 and 45° from the horizontal, as well as vertically from the instrument screen. The analysis of polyethylene recorded dose rates 156 times higher (on average) than steel measurements and 34 times higher than both quartz sand and quartz sandstone. A worst-case exposure scenario was assumed where a user analyses a polyethylene material at arms reach for 1 h each working day for one year. This scenario resulted in an effective body dose of 73.5 ?Sv, equivalent to three to four chest X-rays (20 ?Sv) a year, 20 times lower than the average annual background radiation exposure in Australia and well below the annual exposure limit of 1 mSv for non-radiation workers. This study finds the advantages of using handheld XRF spectrometers far outweighs the risk of low radiation exposure linked to X-ray scattering from samples. PMID:26037330

  9. Atomic cascade of K-p and K-d atoms and Doppler broadening contribution on x-ray widths

    NASA Astrophysics Data System (ADS)

    Kalantari, S. Z.; M. Raeisi, G.

    2010-01-01

    In this article we present a new calculation of the cascade of K-p and K-d atoms by the Monte Carlo method. Energy dependence of the collisional cascade processes is taken into account. The x-ray yields due to the radiative transition during the cascade are also calculated. We compare our results with the previous calculations by others and by KEK and DEAR experimental data for K-p atoms. We have also investigated the kinetic energy distribution of K-p atoms and the role of Coulomb transition on x-ray yields. Finally, the Doppler broadening contribution on the measured width of x-ray spectra are determined. In order to study the strong interaction in low energies, our results for x-ray yields from K-p and K-d atoms can be compared with the forthcoming SIDDHARTA collaboration results.

  10. 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

  11. X-ray fluorescence computed tomography (XFCT) imaging of gold nanoparticle-loaded objects using 110 kVp x-rays.

    PubMed

    Cheong, Seong-Kyun; Jones, Bernard L; Siddiqi, Arsalan K; Liu, Fang; Manohar, Nivedh; Cho, Sang Hyun

    2010-02-01

    A conventional x-ray fluorescence computed tomography (XFCT) technique requires monochromatic synchrotron x-rays to simultaneously determine the spatial distribution and concentration of various elements such as metals in a sample. However, the synchrotron-based XFCT technique appears to be unsuitable for in vivo imaging under a typical laboratory setting. In this study we demonstrated, for the first time to our knowledge, the possibility of performing XFCT imaging of a small animal-sized object containing gold nanoparticles (GNPs) at relatively low concentrations using polychromatic diagnostic energy range x-rays. Specifically, we created a phantom made of polymethyl methacrylate plastic containing two cylindrical columns filled with saline solution at 1 and 2 wt% GNPs, respectively, mimicking tumors/organs within a small animal. XFCT scanning of the phantom was then performed using microfocus 110 kVp x-ray beam and cadmium telluride (CdTe) x-ray detector under a pencil beam geometry after proper filtering of the x-ray beam and collimation of the detector. The reconstructed images clearly identified the locations of the two GNP-filled columns with different contrast levels directly proportional to gold concentration levels. On the other hand, the current pencil-beam implementation of XFCT is not yet practical for routine in vivo imaging tasks with GNPs, especially in terms of scanning time. Nevertheless, with the use of multiple detectors and a limited number of projections, it may still be used to image some objects smaller than the current phantom size. The current investigation suggests several modification strategies of the current XFCT setup, such as the adoption of the quasi-monochromatic cone/fan x-ray beam and XFCT-specific spatial filters or pinhole detector collimators, in order to establish the ultimate feasibility of a bench-top XFCT system for GNP-based preclinical molecular imaging applications. PMID:20071757

  12. Macro and micro full field x-ray fluorescence with an X-ray pinhole camera presenting high energy and high spatial resolution.

    PubMed

    Romano, Francesco Paolo; Caliri, Claudia; Cosentino, Luigi; Gammino, Santo; Giuntini, Lorenzo; Mascali, David; Neri, Lorenzo; Pappalardo, Lighea; Rizzo, Francesca; Taccetti, Francesco

    2014-11-01

    This work describes a tabletop (50 cm × 25 cm × 25 cm) full field X-ray pinhole camera (FF-XPC) presenting high energy- and high spatial-resolution. The FF-XPC consists of a conventional charge-coupled device (CCD) detector coupled, in a coaxial geometry, to a pinhole collimator of small diameter. The X-ray fluorescence (XRF) is induced on the samples with an external low-power X-ray tube. The use of the CCD as an energy dispersive X-ray detector was obtained by adopting a multi-image acquisition in single photon counting and by developing a processing algorithm to be applied in real-time to each of the acquired image-frames. This approach allowed the measurement of X-ray spectra with an energy resolution down to 133 eV at the reference value of 5.9 keV. The detection of the X-ray fluorescence through the pinhole-collimator allowed the two-dimensional elemental mapping of the irradiated samples. Two magnifications (M), determined by the relative sample-pinhole-CCD distances, are used in the present setup. A low value of M (equal to 0.35×) allows the macro-FF-XRF of large area samples (up to 4 × 4 cm(2)) with a spatial resolution down to 140 ?m; a large magnification (M equal to 6×) is used for the micro-FF-XRF of small area samples (2.5 × 2.5 mm(2)) with a spatial resolution down to 30 ?m. PMID:25284509

  13. AUTOMATIC PARTICULATE SULFUR MEASUREMENTS WITH A DICHOTOMOUS SAMPLER AND ON-LINE X-RAY FLUORESCENCE ANALYSIS

    EPA Science Inventory

    An instrument is described which employs a dichotomous sampler to acquire fine particulate samples on a continuous tape filter. Analyses for elemental sulfur are performed immediately following acquisition using a sensitive X-ray fluorescence spectrometer. Sample sequencing, data...

  14. Atomic physics with hard X-rays from high brilliance synchrotron light sources

    SciTech Connect

    Southworth, S.; Gemmell, D.

    1996-08-01

    A century after the discovery of x rays, the experimental capability for studying atomic structure and dynamics with hard, bright synchrotron radiation is increasing remarkably. Tempting opportunities arise for experiments on many-body effects, aspects of fundamental photon-atom interaction processes, and relativistic and quantum-electrodynamic phenomena. Some of these possibilities are surveyed in general terms.

  15. Imaging nonequilibrium atomic vibrations with x-ray diffuse scattering

    PubMed Central

    Trigo, M.; Chen, J.; Vishwanath, V. H.; Sheu, Y. M.; Graber, T.; Henning, R.; Reis, D. A.

    2011-01-01

    We use picosecond x-ray diffuse scattering to image the nonequilibrium vibrations in the lattice following ultrafast laser excitation. We present images of nonequilibrium phonons in InP and InSb throughout the Brillouin zone which remain out of equilibrium up to nanoseconds. The results are analyzed using a Born model that helps identify the phonon branches contributing to the observed features in the time-resolved diffuse scattering. In InP this analysis shows a delayed increase in the transverse-acoustic (TA) phonon population along high-symmetry directions accompanied by a decrease in the longitudinal-acoustic phonons. In InSb the increase in TA phonon population is less directional. PMID:21580798

  16. Simultaneous measurements of X-ray reflectivity and grazing incidence fluorescence at BL-16 beamline of Indus-2.

    PubMed

    Das, Gangadhar; Kane, S R; Khooha, Ajay; Singh, A K; Tiwari, M K

    2015-05-01

    A new multipurpose x-ray reflectometer station has been developed and augmented at the microfocus beamline (BL-16) of Indus-2 synchrotron radiation source to facilitate synchronous measurements of specular x-ray reflectivity and grazing incidence x-ray fluorescence emission from thin layered structures. The design and various salient features of the x-ray reflectometer are discussed. The performance of the reflectometer has been evaluated by analyzing several thin layered structures having different surface interface properties. The results reveal in-depth information for precise determination of surface and interface properties of thin layered materials demonstrating the immense potential of the combined measurements of x-ray reflectivity and grazing incidence fluorescence on a single reflectometer. PMID:26026553

  17. A new fundamental parameter based calibration procedure for micro X-ray fluorescence spectrometers

    NASA Astrophysics Data System (ADS)

    Wolff, Timo; Malzer, Wolfgang; Mantouvalou, Ioanna; Hahn, Oliver; Kanngießer, Birgit

    2011-02-01

    Fundamental parameter based quantification of X-ray fluorescence (XRF) measurement data requires an accurate knowledge of the spectrometer parameters, including the spectral distribution of the excitation radiation. In case of micro-XRF where a polycapillary optic is utilized in the excitation channel this distribution is changed due to the transmission properties of the lens. A new calibration procedure, based on fluorescence data of thin standard samples, was developed to determine the excitation spectrum, i.e., the product of the X-ray tube spectrum and the transmission of the used X-ray optic of a micro-XRF setup. The calibration result was validated by the quantitative analyses of certified multi-element reference standards and shows uncertainties in the order of 2% for main components, 10% for minor elements and 25% for trace elements. The influence of secondary order effects like Coster-Kronig transitions and cascade effects is analyzed and the accuracy of fundamental parameters in common databases is discussed.

  18. A new method for x-ray fluorescence analysis of contaminated material. Final Report

    SciTech Connect

    Grodzins, Lee; Niland, John

    2002-05-23

    Niton has successfully completed the objectives of the Phase II program to build a hand-held, x-ray fluorescent analyzer optimized for DOE decontamination and decommissioning activities in the field. A two-pound x-ray fluorescence analyzer was developed that contains 3 radioactive sources, emitting 3 widely spaced monochromatic x-rays, to give the lowest detection limits for the full range of toxic elements, from chromium to plutonium. A rapid, fundamental- parameters algorithm was developed that yields quantitative results in less than 1 second. High-resolution silicon drift detectors and silicon PIN diodes give excellent efficiency and speed. These results from Phase II have been introduced into the XL 300, 700 and 800 commercial products series. More than 800 of these instruments, yielding revenues of more than $20 million dollars, have been sold since the first 3-source instrument was introduced in 1998. A direct consequence of the Phase II funding has been the growth of Niton from 20 people to its present size of 60.

  19. Analysis of nuclear materials by energy dispersive x-ray fluorescence and spectral effects of alpha decay

    SciTech Connect

    Worley, Christopher G [Los Alamos National Laboratory

    2009-01-01

    Energy dispersive X-ray fluorescence (EDXRF) spectra collected from alpha emitters are complicated by artifacts inherent to the alpha decay process, particularly when using portable instruments. For example, {sup 239}Pu EDXRF spectra exhibit a prominent uranium L X-ray emission peak series due to sample alpha decay rather than source-induced X-ray fluorescence. A portable EDXRF instrument was used to collect spectra from plutonium, americium, and a Pu-contaminated steel sample. The plutonium sample was also analyzed by wavelength dispersive XRF to demonstrate spectral differences observed when using these very different instruments.

  20. Trends in total reflection X-ray fluorescence spectrometry for metallic contamination control in semiconductor nanotechnology

    NASA Astrophysics Data System (ADS)

    Hellin, David; De Gendt, Stefan; Valckx, Nick; Mertens, Paul W.; Vinckier, Chris

    2006-05-01

    The development of transistor manufacturing into the nanoscale regime is accompanied by a continuous awareness concern for contamination control. The ever-increasing demands for analysis sensitivity (in the sub-10 9 at/cm 2 regime) combined with the introduction of new materials (i.e. non-silicon based) put severe challenges on the application of analytical techniques for atomic level contamination monitoring. Since many years, total reflection X-ray fluorescence spectrometry (TXRF) has developed as a preferred technique, ideally suitable due to the excellent reflectivity and flatness of the starting Si substrates. Driven by performance enhancement requirements, many new materials are being introduced at the substrate level (Ge, III/V compounds for higher mobility), gate stack (alternative dielectric materials and gate electrodes for capacitance scaling) and interconnect level (low-k and copper for faster switching). This paper reviews some recent developments in the state-of-the-art TXRF developments for semiconductor applications. Among the focus areas are the expansion of the elemental range (through multi-excitation line selection or multi-excitation source to excite low Z as well as high Z elements in one analysis sweep) and dynamic range (by pre-concentration techniques, synchrotron radiation analysis and detector developments). Further, emphasis is also focused towards quantification issues—whereby the three methodologies (micro-droplet, film and bulk type standards) are critically reviewed. Also, a recent development of sweeping TXRF, suitable for fast screening of large surface areas is being discussed. The applications of TXRF in a semiconductor environment are being reviewed. Finally, the performance of TXRF for the various semiconductor applications is assessed with respected to competitive techniques.

  1. Quantifying trace elements in individual aquatic protist cells with a synchrotron x-ray fluorescence microprobe.

    SciTech Connect

    Twining, B. S.; Baines, S. B.; Fisher, N. S.; Maser, J.; Vogt, S.; Jacobsen, C.; Tovar-Sanchez, A.; Sanudo-Wihelmy, S. A.; Experimental Facilities Division (APS); Stony Brook Univ.

    2003-01-01

    The study of trace metal cycling by aquatic protists is limited by current analytical techniques. Standard 'bulk' element analysis techniques that rely on physical separations to concentrate cells for analysis cannot separate cells from co-occurring detrital material or other cells of differing taxonomy or trophic function. Here we demonstrate the ability of a synchrotron-based X-ray fluorescence (SXRF) microprobe to quantify the elements Si, Mn, Fe, Ni, and Zn in individual aquatic protist cells. This technique distinguishes between different types of cells in an assemblage and between cells and other particulate matter. Under typical operating conditions, the minimum detection limits are 7.0 x 10{sup -16} mol {mu}m{sup -2} for Si and between 5.0 x 10{sup -20} and 3.9 x 10{sup -19} mol {mu}m{sup -2} for Mn, Fe, Ni, and Zn; this sensitivity is sufficient to detect these elements in cells from even the most pristine waters as demonstrated in phytoplankton cells collected from remote areas of the Southern Ocean. Replicate analyses of single cells produced variations of <5% for Si, Mn, Fe, and Zn and <10% for Ni. Comparative analyses of cultured phytoplankton cells generally show no significant differences in cellular metal concentrations measured with SXRF and standard bulk techniques (spectrophotometry and graphite furnace atomic absorption spectrometry). SXRF also produces two-dimensional maps of element distributions in cells, thereby providing information not available with other analytical approaches. This technique enables the accurate and precise measurement of trace metals in individual aquatic protists collected from natural environments.

  2. Total reflection of x-ray fluorescence (TXRF): a mature technique for environmental chemical nanoscale metrology

    NASA Astrophysics Data System (ADS)

    Borgese, L.; Zacco, A.; Bontempi, E.; Colombi, P.; Bertuzzi, R.; Ferretti, E.; Tenini, S.; Depero, L. E.

    2009-08-01

    Total reflection x-ray fluorescence (TXRF) is a technique well established for chemical analysis of samples deposited as a thin layer. Nowadays it is mainly employed for electronic industry quality control. Recently, very compact and economic TXRF instrumentation was proposed. Combining this with the capability to analyze liquid samples, this technique is suitable to be employed in many different applications, comprising the very critical field of environmental analysis. Comparisons with the standard atomic absorption spectroscopy (AAS) technique show that TXRF is a practical, accurate, and reliable technique. Indeed, round-robin activities have already been started. Despite the efficiency and economy of the developed portable TXRF instrumentation, this is not widely employed for chemical laboratory analysis probably because TXRF is not an officially recognized technique, i.e. it is not yet normative-subjected. This fact could also be due to the long background of analytical applications developed for AAS, ICPS or inductively coupled plasma mass spectroscopy (ICP-MS) up to now. In this paper, we present a work of environmental monitoring of an industrial site, performed by means of bioindicators (lichens). The analysis of trace elements concentration in lichen was usually conducted with spectrophotometric techniques, such as AAS and ICP-MS, which were accepted by common regulations and normative-subjected. In this study, we accomplished a comparative lichen analysis by AAS and TXRF. The reproducibility of the obtained results showed the high correspondence between the two techniques. This comparison highlighted the versatility of the TXRF apparatus that allowed more rapid and simultaneous element detection. The obtained results suggested that this portable TXRF system could be suitable for regulation to produce certificated analysis upto ppb concentrations for some elements.

  3. A hybrid fluorescence tomography and x-ray CT system for quantitative molecular imaging

    NASA Astrophysics Data System (ADS)

    Lin, Yuting; Barber, William C.; Iwanczk, Jan S.; Roeck, Werner W.; Nalcioglu, Orhan; Gulsen, Gultekin

    2010-02-01

    A gantry-based hybrid fluorescence and x-ray computed tomography (FT/CT) system is developed for quantitative molecular imaging. The performance of the dual modality FT/CT system is evaluated using an irregular shaped phantom with an inclusion containing Indocyanine-Green (ICG). The anatomical data from CT provides structural a priori information for the FT inverse problem. Although a 4.2 mm diameter inclusion can be resolved in the reconstructed concentration image without any a priori information, ICG concentration in the inclusion is recovered with 75% error. On the other hand, the error in the recovered ICG concentration reduces to 15% when a priori information from CT is utilized. The results demonstrate that accurate fluorophore concentration can only be obtained when x-ray CT structural a priori information is available.

  4. ROLE OF X-RAY FLUORESCENCE IN A MODERN GEOCHEMICAL LABORATORY.

    USGS Publications Warehouse

    Taggart, Joseph E.

    1985-01-01

    Because modern geochemical laboratories can seldom have all new analytical equipment, it is clear that priorities must be assigned and choices made when selecting each new instrument. X-ray fluorescence (XRF) spectroscopy has come to play a vital role in this environment largely because it is a dependable, multielement, rapid method that covers a wide range of elemental concentrations, commonly with only one sample preparation. The following discussion centers on the role of modern XRF instrumentation in the resolution of geochemical problems. In order to present a comprehensive view of this role, this paper draws upon a great deal of information from numerous X-ray laboratories visited in the United States and Canada.

  5. Fluorescent X-Ray Computed Tomography towards Molecular Imaging: Proof-of-Concept Experiments

    SciTech Connect

    Yuasa, Tetsuya; Huo, Qingkai; Akatsuka, Takao [Yamagata University, Yonezawa, Yamagata, 992-8510 (Japan); Takeda, Tohoru [University of Tsukuba, Tsukuba, Ibaraki, 305-8575 (Japan); Hyodo, Kazuyuki [KEK, Tsukuba, Ibaraki, 305-0801 (Japan); Dilmanian, F. Avraham [Brookhaven National Laboratory, Upton, NY, 11973 (United States)

    2009-03-10

    By means of fluorescent x-ray computed tomography (FXCT) one can detect and image a distribution of non-radioactive imaging agent, e.g., iodine, in a biomedical subject at a high spatial resolution, so it can be a novel molecular imaging modality. We have been studying an FXCT system using synchrotron radiation for in-vivo imaging brains of small animals such as mouse, or rat. For the purpose, we propose a fast FXCT imaging method based on the novel geometry. In this study, we prove the feasibility of this concept and investigate its imaging properties, including spatial and contrast resolutions and quantitativeness, by imaging an acrylic phantom and a normal mouse brain using a preliminary imaging system with monochromatic synchrotron x rays.

  6. Application of X-ray fluorescence in investigations of Bohemian historical manuscripts.

    PubMed

    Cechák, Tomás; Trojek, Tomás; Musílek, Ladislav; Paulusová, Hana

    2010-01-01

    In this work we present the application of X-ray fluorescence analysis (XRFA) in an investigation of the Land Register and the Register of the Court of the Kingdom of Bohemia and the manuscript of the Homiliary of the Opatovice Monastery from the 12th century. Radionuclide sources emitting radiation at an appropriate energy level and an X-ray tube were used to excite the characteristic radiation. A spectrometric Si(Li) detector and a Si-PIN detector with Peltier cooling were used to detect the excited characteristic radiation. Several types of pigments were identified and compositions of inks used within almost 5 centuries in the offices at the Prague Castle were determined. PMID:19914081

  7. Chemical effect on the K shell x-ray fluorescence parameters of some Ce compounds.

    PubMed

    Tur?ucu, A; Demir, D

    2013-07-01

    Chemical effects on the K?/K? x-ray intensity ratios, fluorescence yields wK and vacancy transfer probabilities ?KL for some Ce compounds were investigated. In this study, the samples were excited by 59.54 keV ?-rays from a 5Ci (241)Am annular radioactive source. K x-rays emitted by samples were counted by an HPGe detector with a resolution of 182 eV at 5.9 keV. The experimental values were compared with the theoretical and other experimental values. The aim of these measurements was to characterize the dependence of the line position and line width with the chemical environment changes. PMID:23500654

  8. Elemental investigation on Spanish dinosaur bones by x-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Brunetti, Antonio; Piga, Giampaolo; Lasio, Barbara; Golosio, Bruno; Oliva, Piernicola; Stegel, Giovanni; Enzo, Stefano

    2013-07-01

    In this paper we examine the chemical composition results obtained on a collection of 18 dinosaur fossil bones from Spain studied using a portable x-ray fluorescence spectrometer together with a reverse Monte Carlo numerical technique of data analysis. This approach is applied to the hypothesis of arbitrarily rough surfaces in order to account for the influence of the surface state of specimens on the chemical content evaluation. It is confirmed that the chemical content of elements is essential for understanding the changes brought about by diagenetic and taphonomic processes. However, for precise knowledge of what changes fossil bones have undergone after animal life and burial, it is necessary to use a multi-technique approach making use of other instruments like x-ray diffraction in order to describe accurately the transformations undergone by the mineralogical and bioinorganic phases and the properties of specific molecular groups.

  9. Thermoelectrically cooled semiconductor detectors for portable energy-dispersive x-ray fluorescence equipment

    NASA Astrophysics Data System (ADS)

    Cesareo, Roberto; Castellano, Alfredo; Fiorini, Carlo; Gigante, Giovanni E.; Iwanczyk, Jan S.; Longoni, Antonio; Pantazis, John A.; Pena Chapa, Juan L.; Rosales, Marco A.

    1997-07-01

    Thermoelectrically cooled semiconductor detectors, such as Si- PIN, Si-strip and HgI(subscript 2), coupled to miniaturized low-power x-ray tubes, are well suited for constructing portable systems for energy-dispersive x-ray fluorescence analysis (EDXRF) of samples of archaeological interest. The Si-PIN detector is characterized by a thickness of about 300 micrometer, an area of about 2 by 3 mm(superscript 2), an energy resolution of about 250 - 300 eV at 5.9 keV and an entrance window of 75 micrometers. The Si-strip detector has approximate the same area and thickness, but an energy resolution of 145 eV at 5.9 keV. The efficiency of these detectors is around 100% from 4 to 10 keV, and then decreases versus energy, reaching 10% at 30 keV. Coupled to a miniaturized 10 kV, 0.1 mA, Ca-anode or to a miniaturized 30 kV, 0.1 mA, W-anode x-ray tubes, completely portable systems can be constructed, which are able to analyze K-lines of elements up to about silver, and L-lines of heavy elements. The HgI(subscript 2) detector has an efficiency of about 100% in the whole range of x rays, and an energy resolution of about 200 eV at 5.9 keV. Coupled to a small 50 kV, 1 mA, W- anode x-ray tube, a portable system can be constructed, for analysis of practically all elements. These equipments were applied to analysis in the field of archaeometry and in all applications for which portable systems are needed or at least useful (for example x-ray transmission measurements, x-ray microtomography and so on). More specifically, concerning EDXRF analysis, ancient gold samples were analyzed in Rome, in Mexico City and in Milan, nuragic bronzes in Sassari, ceramics of various origin in Merida, La Habana and Sassari, and sulfur (due to pollution) in an old Roman fresco in S. Stefano Rotondo (Rome). Concerning transmission measurements, ancient copper coins and wood samples were analyzed, and microtomographic measurements are in progress to improve the quality of the image.

  10. X-Ray Diffraction and Fluorescence Measurements for In-situ Planetary Instruments

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    The X-Ray Diffraction (XRD) instruments are core components of the forthcoming NASA Mars Science Laboratory (MSL) and ESA/NASA EXOMARS missions and will provide the first demonstrations of an XRF/XRD instrument’s capabilities in-situ on an extraterrestrial planetary surface. The University of Leicester team is part of the Italy-UK collaboration that is responsible for building the ExoMars X-Ray Diffraction instrument, Mars XRD. The ExoMars X-ray diffraction instrument incorporates an 55-Fe radioisotope source and three fixed-position CCDs to simultaneously acquire an X-Ray fluorescence spectrum and a diffraction pattern providing a measurement of both elemental and mineralogical composition [1]. The CCDs cover an angular range from 6 to 65-deg enabling the analysis of silicates, from clays, or other phyllosilicates characterised by varying d-spacings, to oxides, and carbonates or evaporites. The identification of hydrous minerals may help identify past Martian hydrothermal systems capable of preserving traces of life. Here we present some initial findings from XRF and XRD tests carried out at the University of Leicester using an 55-Fe source and X-ray sensitive CCD [1]. The XRD/XRD test system consists of a single CCD on a motorised arm, an 55-Fe X-ray source, source collimator and a sample table which approximately replicate the reflection geometry of the XRD instrument. It was used to test geological reference standard materials and Martian analogues. Incidence angle and CCD angles on both the diffraction and fluorescence results were evaluated. A key area of interest is the effect of sample roughness on the XRD/XRF results. We present results from testing pressed powder pellet samples of varying surface roughness, and a comparison with model results [2]. So far we have found that increased roughness causes a reduced intensity at lower take-off angles. Several methods for measuring surface roughness of the samples have been used including an Alicona Infinite Focus microscope. [1] Marinangeli et al. (2007) LPSC #1322 [2] Hansford et al. (2010) EGU General Assembly 2010

  11. Correlative VIS-fluorescence and soft X-ray cryo-microscopy/tomography of adherent cells.

    PubMed

    Hagen, Christoph; Guttmann, Peter; Klupp, Barbara; Werner, Stephan; Rehbein, Stefan; Mettenleiter, Thomas C; Schneider, Gerd; Grünewald, Kay

    2012-02-01

    Soft X-ray cryo-microscopy/tomography of vitreous samples is becoming a valuable tool in structural cell biology. Within the 'water-window' wavelength region (2.34-4.37nm), it provides absorption contrast images with high signal to noise ratio and resolution of a few tens of nanometer. Soft X-rays with wavelengths close to the K-absorption edge of oxygen penetrate biological samples with thicknesses in the micrometer range. Here, we report on the application of a recently established extension of the transmission soft X-ray cryo-microscope (HZB TXM) at the beamline U41-XM of the BESSY II electron storage ring by an in-column epi-fluorescence and reflected light cryo-microscope. We demonstrate the new capability for correlative fluorescence and soft X-ray cryo-microscopy/tomography of this instrument along a typical life science experimental approach - the correlation of a fluorophore-tagged protein (pUL34-GFP of pseudorabies virus, PrV, the nuclear membrane-anchored component of the nuclear egress complex of the Herpesviridae which interacts with viral pUL31) in PrV pUL34-GFP/pUL31 coexpressing mammalian cells, with virus-induced vesicular structures in the nucleus, expanding the nucleoplasmic reticulum. Taken together, our results demonstrate new possibilities to study the role of specific proteins in substructures of adherent cells, especially of the nucleus in toto, accessible to electron microscopy in thinned samples only. PMID:22210307

  12. Experimental demonstration of novel imaging geometries for x-ray fluorescence computed tomography

    PubMed Central

    Fu, Geng; Meng, Ling-Jian; Eng, Peter; Newville, Matt; Vargas, Phillip; Riviere, Patrick La

    2013-01-01

    Purpose: X-ray fluorescence computed tomography (XFCT) is an emerging imaging modality that maps the three-dimensional distribution of elements, generally metals, in ex vivo specimens and potentially in living animals and humans. At present, it is generally performed at synchrotrons, taking advantage of the high flux of monochromatic x rays, but recent work has demonstrated the feasibility of using laboratory-based x-ray tube sources. In this paper, the authors report the development and experimental implementation of two novel imaging geometries for mapping of trace metals in biological samples with ?50–500 ?m spatial resolution. Methods: One of the new imaging approaches involves illuminating and scanning a single slice of the object and imaging each slice's x-ray fluorescent emissions using a position-sensitive detector and a pinhole collimator. The other involves illuminating a single line through the object and imaging the emissions using a position-sensitive detector and a slit collimator. They have implemented both of these using synchrotron radiation at the Advanced Photon Source. Results: The authors show that it is possible to achieve 250 eV energy resolution using an electron multiplying CCD operating in a quasiphoton-counting mode. Doing so allowed them to generate elemental images using both of the novel geometries for imaging of phantoms and, for the second geometry, an osmium-stained zebrafish. Conclusions: The authors have demonstrated the feasibility of these two novel approaches to XFCT imaging. While they use synchrotron radiation in this demonstration, the geometries could readily be translated to laboratory systems based on tube sources. PMID:23718594

  13. L-shell x-ray fluorescence computed tomography (XFCT) imaging of Cisplatin

    PubMed Central

    Bazalova, Magdalena; Ahmad, Moiz; Pratx, Guillem; Xing, Lei

    2014-01-01

    X-ray fluorescence computed tomography (XFCT) imaging has been focused on the detection of K-shell X-rays. The potential utility of L-shell x-ray XFCT is, however, not well studied. Here we report the first Monte Carlo (MC) simulation of preclinical L-shell XFCT imaging of Cisplatin. We built MC models for both L- and K-shell XFCT with different excitation energies (15 and 30 keV for L-shell and 80 keV for K-shell XFCT). Two small-animal sized imaging phantoms of 2-cm and 4-cm diameter containing a series of objects of 0.6 to 2.7 mm in diameter at 0.7 to 16 mm depths with 10 to 250 ?g/mL concentrations of Pt are used in the study. Transmitted and scattered x-rays were collected with photon-integrating transmission detector and photon-counting detector arc, respectively. Collected data were rearranged into XFCT and transmission CT sinograms for image reconstruction. XFCT images were reconstructed with filtered back-projection (FBP) and with iterative maximum-likelihood expectation maximization (ML-EM) without and with attenuation correction. While K-shell XFCT was capable of providing accurate measurement of Cisplatin concentration, its sensitivity was 4.4 and 3.0 times lower than that of L-shell XFCT with 15 keV excitation beam for the 2-cm and 4-cm diameter phantom, respectively. With inclusion of excitation and fluorescence beam attenuation correction, we found that L-shell XFCT was capable of providing fairly accurate information of Cisplatin concentration distribution. With a dose of 29 and 58 mGy, clinically relevant Cisplatin Pt concentrations of 10 ?g/mg could be imaged with L-shell XFCT inside a 2-cm and 4-cm diameter object, respectively. PMID:24334507

  14. Correlative VIS-fluorescence and soft X-ray cryo-microscopy/tomography of adherent cells

    PubMed Central

    Hagen, Christoph; Guttmann, Peter; Klupp, Barbara; Werner, Stephan; Rehbein, Stefan; Mettenleiter, Thomas C.; Schneider, Gerd; Grünewald, Kay

    2012-01-01

    Soft X-ray cryo-microscopy/tomography of vitreous samples is becoming a valuable tool in structural cell biology. Within the ‘water-window’ wavelength region (2.34–4.37 nm), it provides absorption contrast images with high signal to noise ratio and resolution of a few tens of nanometer. Soft X-rays with wavelengths close to the K-absorption edge of oxygen penetrate biological samples with thicknesses in the micrometer range. Here, we report on the application of a recently established extension of the transmission soft X-ray cryo-microscope (HZB TXM) at the beamline U41-XM of the BESSY II electron storage ring by an in-column epi-fluorescence and reflected light cryo-microscope. We demonstrate the new capability for correlative fluorescence and soft X-ray cryo-microscopy/tomography of this instrument along a typical life science experimental approach – the correlation of a fluorophore-tagged protein (pUL34-GFP of pseudorabies virus, PrV, the nuclear membrane-anchored component of the nuclear egress complex of the Herpesviridae which interacts with viral pUL31) in PrV pUL34-GFP/pUL31 coexpressing mammalian cells, with virus-induced vesicular structures in the nucleus, expanding the nucleoplasmic reticulum. Taken together, our results demonstrate new possibilities to study the role of specific proteins in substructures of adherent cells, especially of the nucleus in toto, accessible to electron microscopy in thinned samples only. PMID:22210307

  15. Observation of ultralow-level Al impurities on a silicon surface by high-resolution grazing emission x-ray fluorescence excited by synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Kubala-Kuku?, A.; Bana?, D.; Cao, W.; Dousse, J.-Cl.; Hoszowska, J.; Kayser, Y.; Pajek, M.; Salomé, M.; Susini, J.; Szlachetko, J.; Szlachetko, M.

    2009-09-01

    We demonstrate that ultralow-level Al impurities on a silicon surface can be measured by using the high-resolution grazing emission x-ray fluorescence (GEXRF) technique combined with synchrotron-radiation excitation. An Al-impurity level of about 1012atoms/cm2 was reached by observing the AlK? x-ray fluorescence in the resonant Raman-scattering background-“free” regime by choosing an appropriate beam energy below the SiK absorption edge. Present results show that by combining the GEXRF method with the vapor phase decomposition technique the 107atoms/cm2 level can be reached for Al detection on silicon. Finally, we found that the high-resolution GEXRF technique is a sensitive tool to study the morphology of surface nanostructures.

  16. Observation of ultralow-level Al impurities on a silicon surface by high-resolution grazing emission x-ray fluorescence excited by synchrotron radiation

    SciTech Connect

    Kubala-Kukus, A.; Banas, D.; Pajek, M. [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Cao, W.; Dousse, J.-Cl.; Hoszowska, J.; Kayser, Y.; Szlachetko, M. [Department of Physics, University of Fribourg, CH-1700 Fribourg (Switzerland); Salome, M.; Susini, J. [European Synchrotron Radiation Facility (ESRF), F-38043 Grenoble (France); Szlachetko, J. [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Department of Physics, University of Fribourg, CH-1700 Fribourg (Switzerland)

    2009-09-15

    We demonstrate that ultralow-level Al impurities on a silicon surface can be measured by using the high-resolution grazing emission x-ray fluorescence (GEXRF) technique combined with synchrotron-radiation excitation. An Al-impurity level of about 10{sup 12} atoms/cm{sup 2} was reached by observing the Al K{alpha} x-ray fluorescence in the resonant Raman-scattering background-''free'' regime by choosing an appropriate beam energy below the Si K absorption edge. Present results show that by combining the GEXRF method with the vapor phase decomposition technique the 10{sup 7} atoms/cm{sup 2} level can be reached for Al detection on silicon. Finally, we found that the high-resolution GEXRF technique is a sensitive tool to study the morphology of surface nanostructures.

  17. Hyper-filter-fluorescer spectrometer for x-rays above 120 keV

    DOEpatents

    Wang, Ching L. (Livermore, CA)

    1983-01-01

    An apparatus utilizing filter-fluorescer combinations is provided to measure short bursts of high fluence x-rays above 120 keV energy, where there are no practical absorption edges available for conventional filter-fluorescer techniques. The absorption edge of the prefilter is chosen to be less than that of the fluorescer, i.e., E.sub.PRF E.sub.F. In this way, the response function is virtually zero between E.sub.PRF and E.sub.F and well defined and enhanced in an energy band of less than 1000 keV above the 120 keV energy.

  18. Multilayer mirror as a substrate for total reflection X-ray fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Tiwari, M. K.; Sawhney, K. J. S.; Lodha, G. S.

    2010-06-01

    X-ray field intensity generated over a multilayer surface during a strong Bragg reflection condition has been used to analyze the particulate matter deposited on its surface, for the average particles size distribution and detection sensitivity of various elements. The elemental detection sensitivities achieved at Bragg reflection condition are compared to those obtained at incidence angles below critical angle, under total external reflection condition. The results obtained indicate that when big size particles (> 1 ?m) are distributed over a large surface area, the observed fluorescence yields deteriorate by 15-18% in the total external reflection condition, due to strong sample absorption effects. In such a case, use of a multilayer mirror as a sample carrier and fluorescence excitation under Bragg reflection condition provides better fluorescence yield and hence improved detection sensitivity for an element.

  19. Microwave-assisted synthesis of water-soluble, fluorescent gold nanoclusters capped with small organic molecules and a revealing fluorescence and X-ray absorption study.

    PubMed

    Helmbrecht, C; Lützenkirchen-Hecht, D; Frank, W

    2015-03-21

    Colourless solutions of blue light-emitting, water-soluble gold nanoclusters (AuNC) were synthesized from gold colloids under microwave irradiation using small organic molecules as ligands. Stabilized by 1,3,5-triaza-7-phosphaadamantane (TPA) or L-glutamine (GLU), fluorescence quantum yields up to 5% were obtained. AuNC are considered to be very promising for biological labelling, optoelectronic devices and light-emitting materials but the structure-property relationships have still not been fully clarified. To expand the knowledge about the AuNC apart from their fluorescent properties they were studied by X-ray absorption spectroscopy elucidating the oxidation state of the nanoclusters' gold atoms. Based on curve fitting of the XANES spectra in comparison to several gold references, optically transparent fluorescent AuNC are predicted to be ligand-stabilized Au5(+) species. Additionally, their near edge structure compared with analogous results of polynuclear clusters known from the literature discloses an increasing intensity of the feature close to the absorption edge with decreasing cluster size. As a result, a linear relationship between the cluster size and the X-ray absorption coefficient can be established for the first time. PMID:25692478

  20. Atomic structure of machined semiconducting chips: An x-ray absorption spectroscopy study

    SciTech Connect

    Paesler, M.; Sayers, D.

    1988-12-01

    X-ray absorption spectroscopy (XAS) has been used to examine the atomic structure of chips of germanium that were produced by single point diamond machining. It is demonstrated that although the local (nearest neighbor) atomic structure is experimentally quite similar to that of single crystal specimens information from more distant atoms indicates the presence of considerable stress. An outline of the technique is given and the strength of XAS in studying the machining process is demonstrated.

  1. The Bionanoprobe: hard X-ray fluorescence nanoprobe with cryogenic capabilities

    PubMed Central

    Chen, S.; Deng, J.; Yuan, Y.; Flachenecker, C.; Mak, R.; Hornberger, B.; Jin, Q.; Shu, D.; Lai, B.; Maser, J.; Roehrig, C.; Paunesku, T.; Gleber, S. C.; Vine, D. J.; Finney, L.; VonOsinski, J.; Bolbat, M.; Spink, I.; Chen, Z.; Steele, J.; Trapp, D.; Irwin, J.; Feser, M.; Snyder, E.; Brister, K.; Jacobsen, C.; Woloschak, G.; Vogt, S.

    2014-01-01

    Hard X-ray fluorescence microscopy is one of the most sensitive techniques for performing trace elemental analysis of biological samples such as whole cells and tissues. Conventional sample preparation methods usually involve dehydration, which removes cellular water and may consequently cause structural collapse, or invasive processes such as embedding. Radiation-induced artifacts may also become an issue, particularly as the spatial resolution increases beyond the sub-micrometer scale. To allow imaging under hydrated conditions, close to the ‘natural state’, as well as to reduce structural radiation damage, the Bionanoprobe (BNP) has been developed, a hard X-ray fluorescence nanoprobe with cryogenic sample environment and cryo transfer capabilities, dedicated to studying trace elements in frozen-hydrated biological systems. The BNP is installed at an undulator beamline at sector 21 of the Advanced Photon Source. It provides a spatial resolution of 30?nm for two-dimensional fluorescence imaging. In this first demonstration the instrument design and motion control principles are described, the instrument performance is quantified, and the first results obtained with the BNP on frozen-hydrated whole cells are reported. PMID:24365918

  2. Maia X-ray fluorescence imaging: Capturing detail in complex natural samples

    NASA Astrophysics Data System (ADS)

    Ryan, C. G.; Siddons, D. P.; Kirkham, R.; Li, Z. Y.; de Jonge, M. D.; Paterson, D. J.; Kuczewski, A.; Howard, D. L.; Dunn, P. A.; Falkenberg, G.; Boesenberg, U.; De Geronimo, G.; Fisher, L. A.; Halfpenny, A.; Lintern, M. J.; Lombi, E.; Dyl, K. A.; Jensen, M.; Moorhead, G. F.; Cleverley, J. S.; Hough, R. M.; Godel, B.; Barnes, S. J.; James, S. A.; Spiers, K. M.; Alfeld, M.; Wellenreuther, G.; Vukmanovic, Z.; Borg, S.

    2014-04-01

    Motivated by the challenge of capturing complex hierarchical chemical detail in natural material from a wide range of applications, the Maia detector array and integrated realtime processor have been developed to acquire X-ray fluorescence images using X-ray Fluorescence Microscopy (XFM). Maia has been deployed initially at the XFM beamline at the Australian Synchrotron and more recently, demonstrating improvements in energy resolution, at the P06 beamline at Petra III in Germany. Maia captures fine detail in element images beyond 100 M pixels. It combines a large solid-angle annular energy-dispersive 384 detector array, stage encoder and flux counter inputs and dedicated FPGA-based real-time event processor with embedded spectral deconvolution. This enables high definition imaging and enhanced trace element sensitivity to capture complex trace element textures and place them in a detailed spatial context. Maia hardware and software methods provide per pixel correction for dwell, beam flux variation, dead-time and pileup, as well as off-line parallel processing for enhanced throughput. Methods have been developed for real-time display of deconvoluted SXRF element images, depth mapping of rare particles and the acquisition of 3D datasets for fluorescence tomography and XANES imaging using a spectral deconvolution method that tracks beam energy variation.

  3. Monolithic polycapillary focusing optics and their applications in microbeam x-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Gao, N.; Ponomarev, I. Yu.; Xiao, Q. F.; Gibson, W. M.; Carpenter, D. A.

    1996-09-01

    Monolithic polycapillary focusing optics can collect a large solid angle of x rays from a point source and form intense focused beams for microbeam x-ray fluorescence (MXRF) analysis. Such an optic was tested and characterized in a MXRF setup. For the Cu K? line, the measured focal spot size of the optic was 43 ?m full width at half-maximum (FWHM). With the 16 W microfocusing x-ray source (50 ?m×10 ?m), the average Cu K? intensities over the focal spot was measured to be 8.9×104 photons/s/?m2. When compared to a straight single channel capillary optic with approximately the same output beam size, an intensity gain of 44 was obtained. The optic was applied to the MXRF setup to analyze trace elements in various samples and a minimum detection limit (MDL) of about 2 pg was achieved for the transition elements (V, Cr, Mn, and Fe). The optic was also used to map the distributions of trace elements in various samples.

  4. Trace element abundance determinations by Synchrotron X Ray Fluorescence (SXRF) on returned comet nucleus mineral grains

    NASA Technical Reports Server (NTRS)

    Flynn, G. J.; Sutton, S. R.

    1989-01-01

    Trace element analyses were performed on bulk cosmic dust particles by Proton Induced X Ray Emission (PIXE) and Synchrotron X Ray Fluorescence (SXRF). When present at or near chondritic abundances the trace elements K, Ti, Cr, Mn, Cu, Zn, Ga, Ge, Se, and Br are presently detectable by SXRF in particles of 20 micron diameter. Improvements to the SXRF analysis facility at the National Synchrotron Light Source presently underway should increase the range of detectable elements and permit the analysis of smaller samples. In addition the Advanced Photon Source will be commissioned at Argonne National Laboratory in 1995. This 7 to 8 GeV positron storage ring, specifically designed for high-energy undulator and wiggler insertion devices, will be an ideal source for an x ray microprobe with one micron spatial resolution and better than 100 ppb elemental sensitivity for most elements. Thus trace element analysis of individual micron-sized grains should be possible by the time of the comet nucleus sample return mission.

  5. X-ray fluorescence analysis of iron and manganese distribution in primary dopaminergic neurons

    PubMed Central

    Du?i?, Tanja; Barski, Elisabeth; Salome, Murielle; Koch, Jan C; Bähr, Mathias; Lingor, Paul

    2013-01-01

    Transition metals have been suggested to play a pivotal role in the pathogenesis of Parkinson's disease. X-ray microscopy combined with a cryogenic setup is a powerful method for elemental imaging in low concentrations and high resolution in intact cells, eliminating the need for fixation and sectioning of the specimen. Here, we performed an elemental distribution analysis in cultured primary midbrain neurons with a step size in the order of 300 nm and ? 0.1 ppm sensitivity under cryo conditions by using X-ray fluorescence microscopy. We report the elemental mappings on the subcellular level in primary mouse dopaminergic (DAergic) and non-DAergic neurons after treatment with transition metals. Application of Fe2+ resulted in largely extracellular accumulation of iron without preference for the neuronal transmitter subtype. A quantification of different Fe oxidation states was performed using X-ray absorption near edge structure analysis. After treatment with Mn2+, a cytoplasmic/paranuclear localization of Mn was observed preferentially in DAergic neurons, while no prominent signal was detectable after Mn3+ treatment. Immunocytochemical analysis correlated the preferential Mn uptake to increased expression of voltage-gated calcium channels in DAergic neurons. We discuss the implications of this differential elemental distribution for the selective vulnerability of DAergic neurons and Parkinson's disease pathogenesis. PMID:23106162

  6. Proton-induces and x-ray induced fluorescence analysis of scoliotic tissue

    SciTech Connect

    Panessa-Warren, B J; Kraner, H W; Jones, K W; Weiss, L S

    1980-02-01

    Adolescent idiopathic scoliosis is characterized by a curvature or assymetry of the spine which may become progressively more severe, with clinical symptoms appearing just prior to, or during, puberty. The incidence for scoliosis in the age group from 12 to 14 years of age has been reported as high as 8 to 10%, with more than 80% of the cases occurring in females. Although pathologic changes exist in muscles from both sides of the spinal curvature, and no statistically significant side differences have been reported, morphologic changes suggest that the concanve side is the most affected. This paper reports our preliminary data on the elemental composition of individual muscle fibers derived from convex, concave and gluteal scoliotic muscle, and erythrocytes from scoliotic and normal patients, analyzed by proton induced x-ray emission (PIXE) and x-ray fluorescence spectroscopy (XRF). A new type of specimen holder was designed for this study which offers low x-ray background, minimal absorption and maintenance of a moist environment around the specimen.

  7. Development of Ta-based Superconducting Tunnel Junction X-ray Detectors for Fluorescence XAS

    SciTech Connect

    Friedrich, Stephan; Drury, Owen B. [Lawrence Livermore National Lab, Advanced Detector Group, 7000 East Ave., L-188, Livermore, CA 94550 (United States); Hall, John; Cantor, Robin [STAR Cryoelectronics, 25-A Bisbee Court, Santa Fe, NM 87508 (United States)

    2010-06-23

    We are developing superconducting tunnel junction (STJ) soft X-ray detectors for chemical analysis of dilute samples by fluorescence-detected X-ray absorption spectroscopy (XAS). Our 36-pixel Nb-based STJ spectrometer covers a solid angle {Omega}/4{pi}{approx_equal}10{sup -3}, offers an energy resolution of {approx}10-20 eV FWHM for energies up to {approx}1 keV, and can be operated at total count rates of {approx}10{sup 6} counts/s. For increased quantum efficiency and cleaner response function, we have now started the development of Ta-based STJ detector arrays. Initial devices modeled after our Nb-based STJs have an energy resolution below 10 eV FWHM for X-ray energies below 1 keV, and pulse rise time discrimination can be used to improve their response function for energies up to several keV. We discuss the performance of the Ta-STJs and outline steps towards the next-generation of large STJ detector arrays with higher sensitivity.

  8. [Application of in situ micro energy dispersive X-ray fluorescence analysis in mineralogy].

    PubMed

    Yang, Hai; Ge, Liang-Quan; Gu, Yi; Zhang, Qing-Xian; Xiong, Sheng-Qing

    2013-11-01

    Thirteen rock samples were collected for studying the variation of element content in the mineral during the alteration process from Xinjiang, China. The IED-6000 in situ micro energy dispersive X-ray fluorescence developed by CDUT was applied to get chemical and physical data from minerals. The non-destructive spectrometer is based on a low-power Mo-anode X-ray tube and a Si-PIN peltier cooled X-ray detector. The unique design of the tube's probe allows very close coupling of polycapillary and makes the use of micro-area measurement feasible and efficient. The spectrometer can be integrated into any microscope for analysis. The long axis diameter of beam spot is about 110 microm. According to micro-EDXRF measurement, the tetrahedrite was corrected to pyrite, improving the efficiency and accuracy of the mineral identification. The feldspar of mineralized rock sample is rich in Cu and Zn which can be used as prospecting indicator elements. Element content of Cr, Mn and Co shows negative correlation with the degree of mineralization. PMID:24555398

  9. Preliminary testing of a prototype portable X-ray fluorescence spectrometer

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

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

  10. Analysis of obsidian artifacts in Southern Meso-America using x-ray fluorescence

    SciTech Connect

    Nelson, F.W. [Brigham Young Univ., Provo, UT (United States)

    1996-12-31

    The analysis of obsidian artifacts using X-ray fluorescence (XRF) spectrometry has been an important tool for archaeologists for {approximately}25 yr. However, as methods and instrumentation have improved, more reliable information regarding exchange and routes of exchange has been obtained. In southern Meso-America, obsidian analyses have demonstrated changes in the obsidian geologic sources used by prehistoric peoples through time. These changes in sources of obsidian have been used to describe possible changes of prehistoric trade routes. The methods and results of analysis are described in this paper.

  11. X-ray fluorescence in investigations of cultural relics and archaeological finds.

    PubMed

    Musílek, Ladislav; Cechák, Tomáš; Trojek, Tomáš

    2012-07-01

    Some characteristic features of X-ray fluorescence (XRF) analysis make it an ideal method for investigations of cultural relics and archaeological finds. It has therefore become a standard method used in archaeometry. Paintings, frescos, manuscripts, pottery, metalwork, glass, and many other objects are analysed with the aim of recognising their materials, production technologies and origin, and for identifying counterfeits. This paper reviews various techniques used in XRF analyses of works of art, summarises the advantages and limitations of the method, and presents some typical examples of its use. The general review is supplemented by some techniques used and some results achieved at CTU-FNSPE in Prague. PMID:22099447

  12. Combined backscatter Moessbauer spectrometer/x ray fluorescence analyzer (BaMS/XRF) for extraterrestrial surfaces

    NASA Technical Reports Server (NTRS)

    Shelfer, T. D.; Wills, E. L.; Agresti, D. G.; Pimperl, M. M.; Shen, M. H.; Morris, R. V.; Nguyen, T.

    1993-01-01

    We have designed and tested a prototype combined backscatter Moessbauer spectrometer and x-ray fluorescence analyzer (BaMS/XRF). A space qualified instrument based on this design would be suitable for in-situ use on planetary missions to the surfaces of the Moon (Artemis and lunar outpost), Mars (MESUR), asteroids, or other solid solar system objects. The BaMS/XRF instrument is designed to be capable of concurrent sample analyses for the mineralogy of iron-bearing phases and elemental composition without the need for sample preparation.

  13. An x-ray fluorescence study of lake sediments from ancient Turkey using synchrotron radiation.

    SciTech Connect

    Alatas, A.; Alp, E. E.; Friedman, E. S.; Jennings, G.; Johnson, C. E.; Lai, B.; Mini, S. M.; Sato, Y.; Wilkinson, T. J.; Yener, K. A.

    1999-03-10

    Sediments from relic Lake Golbasi were analyzed by X-ray fluorescence with synchrotrons radiation to determine changes in element concentrations over time with selected elements serving as proxies for environmental change. Increases in Ca and Sr suggest soil formation during a dry period, from ca. 4500 BC to ca. 200 AD at which point K, Rb, Zr, Ti, and Y increase, indicating the return of a wet environment. Soil erosion, represented by Cr and Ni, increases ca. 7000 BC, probably as a consequence of environmental change, prior to suggested exploitation of natural resources by the newly urbanized society of the third millennium BC.

  14. Synchrotron based X-ray fluorescence activities at Indus-2: An overview

    SciTech Connect

    Tiwari, M. K., E-mail: mktiwari@rrcat.gov.in [Indus Synchrotrons Utilisation Division, Raja Ramanna Centre for Advanced Technology, Indore-452013 (India)

    2014-04-24

    X-Ray fluorescence (XRF) spectrometry is a powerful non-destructive technique for elemental analysis of materials at bulk and trace concentration levels. Taking into consideration several advantages of the synchrotron based XRF technique and to fulfill the requirements of Indian universities users we have setup a microfocus XRF beamline (BL-16) on Indus-2 synchrotron light source. The beamline offers a wide range of usages – both from research laboratories and industries; and for researchers working in diverse fields. A brief overview of the measured performance of the beamline, design specifications including various attractive features and recent research activities carried out on the BL-16 beamline are presented.

  15. A dosimetry study for a K-fluorescent x-ray system

    E-print Network

    Beard, Travis Newton

    1975-01-01

    -ray therapy unit as the primary source of radiation. The K-fluorescenc. e radiator targets used were copper, tin, tantalum and lead sheets. The existence of the K-fluorescent beams was confirmed by half value layer measurements and by the analysis of energy... adaptability to being used for such applications as radiation detection instrument calibration and radiation biology studies. The X-ray therapy unit in the Radiological Safety Laboratory, Texas A&M University, was used as the source for the primary X...

  16. Airborne Particulate Matter (PM) filter analysis and modeling by Total reflection X-Ray Fluorescence (TXRF) and X-Ray Standing Wave (XSW)

    PubMed Central

    Borgese, L.; Salmistraro, M.; Gianoncelli, A; Zacco, A.; Lucchini, R.; Zimmerman, N.; Pisani, L.; Siviero, G.; Depero, L. E.; Bontempi, E.

    2011-01-01

    This work is presented as an improvement of a recently introduced method for airborne particulate matter (PM) filter analysis [1]. X-ray Standing Wave (XSW) and Total reflection X-Ray Fluorescence (TXRF) were performed with a new dedicated laboratory instrumentation. The main advantage of performing both XSW and TXRF, is the possibility to distinguish the nature of the sample: if it is a small droplet dry residue, a thin film like or a bulk sample; and to select the angle of total reflection to make TXRF measurements. Finally, the possibility to switch the X-ray source allows to measure with more accuracy lighter and heavier elements (with a a change in X-ray anode, for example from Mo to Cu). The aim of the present study is to lay the theoretical foundation of the new proposed method for airborne PM filters quantitative analysis improving the accuracy and efficiency of quantification by means of an external standard. The theoretical model presented and discussed demonstrated that airborne PM filters can be considered as thin layers. A set of reference samples is prepared in laboratory and used to obtain a calibration curve. Our results demonstrate that the proposed method for quantitative analysis of air PM filters is affordable and reliable without the necessity to digest filters to obtain quantitative chemical analysis, and that the use of XRW improve the accuracy of TXRF analysis. PMID:22284465

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  18. Determination of sulfur and chlorine in fodder by X-ray fluorescence spectral analysis and comparison with other analytical methods

    NASA Astrophysics Data System (ADS)

    Ne?emer, Marijan; Kump, Peter; Raj?evi?, Marija; Ja?imovi?, Radojko; Budi?, Bojan; Ponikvar, Maja

    2003-07-01

    Sulfur and chlorine are essential elements in the metabolic processes of ruminants, and correct planning strategy of ruminant nutrition should provide a sufficient content of S and Cl in the animal's body. S and Cl can be found in various types of animal fodder in the form of organic compounds and minerals. In this work, the Cl and S content in forage was determined by X-ray fluorescence spectrometry (XRF), and its performance was then compared in parallel analyses by instrumental neutron activation analysis (INAA), inductively coupled plasma atomic emission spectrometry (ICP-AES) and potentiometric methods. The results were compared and critically evaluated in order to assess the performance and capability of the XRF technique in analysis of animal fodder.

  19. Particle Mass Measurements and Strong Interaction Studies with Exotic Atoms using X-ray Crystal Spectrometer

    E-print Network

    Titov, Anatoly

    with crystal spectrometer are discussed which aim to improve particle masses and to study hyperon- nucleus Deexcitation and Isotope Exchange of Excited Mesic Hydrogen A. V. Kravtsov, A. I. Mikhailov Àííîòàöèÿ ÏðîöåññûParticle Mass Measurements and Strong Interaction Studies with Exotic Atoms using X-ray Crystal

  20. Non-destructive in situ study of "Mad Meg" by Pieter Bruegel the Elder using mobile X-ray fluorescence, X-ray diffraction and Raman spectrometers

    NASA Astrophysics Data System (ADS)

    Van de Voorde, Lien; Van Pevenage, Jolien; De Langhe, Kaat; De Wolf, Robin; Vekemans, Bart; Vincze, Laszlo; Vandenabeele, Peter; Martens, Maximiliaan P. J.

    2014-07-01

    "Mad Meg", a figure of Flemish folklore, is the subject of a famous oil-on-panel painting by the Flemish renaissance artist Pieter Bruegel the Elder, exhibited in the Museum Mayer van den Bergh (Antwerp, Belgium). This article reports on the in situ chemical characterization of this masterpiece by using currently available state-of-the-art portable analytical instruments. The applied non-destructive analytical approach involved the use of a) handheld X-ray fluorescence instrumentation for retrieving elemental information and b) portable X-ray fluorescence/X-ray diffraction instrumentation and laser-based Raman spectrometers for obtaining structural/molecular information. Next to material characterization of the used pigments and of the different preparation layers of the painting, also the verification of two important historical iconographic hypotheses is performed concerning the economic way of painting by Brueghel, and whether or not he used blue smalt pigment for painting the boat that appears towards the top of the painting. The pigments identified are smalt pigment (65% SiO2 + 15% K2O + 10% CoO + 5% Al2O3) for the blue color present in all blue areas of the painting, probably copper resinate for the green colors, vermillion (HgS) as red pigment and lead white is used to form different colors. The comparison of blue pigments used on different areas of the painting gives no differences in the elemental fingerprint which confirms the existing hypothesis concerning the economic painting method by Bruegel.

  1. Toward atomic resolution diffractive imaging of isolated molecules with x-ray free-electron lasers

    E-print Network

    Stern, Stephan; Filsinger, Frank; Rouzée, Arnaud; Rudenko, Artem; Johnsson, Per; Martin, Andrew V; Barty, Anton; Bostedt, Christoph; Bozek, John D; Coffee, Ryan N; Epp, Sascha; Erk, Benjamin; Foucar, Lutz; Hartmann, Robert; Kimmel, Nils; Kühnel, Kai-Uwe; Maurer, Jochen; Messerschmidt, Marc; Rudek, Benedikt; Starodub, Dmitri G; Thøgersen, Jan; Weidenspointner, Georg; White, Thomas A; Stapelfeldt, Henrik; Rolles, Daniel; Chapman, Henry N; Küpper, Jochen

    2014-01-01

    We give a detailed account of the theoretical analysis and the experimental results of an x-ray-diffraction experiment on quantum-state selected and strongly laser-aligned gas-phase ensembles of the prototypical large asymmetric rotor molecule 2,5-diiodobenzonitrile, performed at the Linac Coherent Light Source [Phys. Rev. Lett. 112, 083002 (2014)]. This experiment is the first step toward coherent diffractive imaging of structures and structural dynamics of isolated molecules at atomic resolution, i. e., picometers and femtoseconds, using x-ray free-electron lasers.

  2. Toward atomic resolution diffractive imaging of isolated molecules with X-ray free-electron lasers.

    PubMed

    Stern, S; Holmegaard, L; Filsinger, F; Rouzée, A; Rudenko, A; Johnsson, P; Martin, A V; Barty, A; Bostedt, C; Bozek, J; Coffee, R; Epp, S; Erk, B; Foucar, L; Hartmann, R; Kimmel, N; Kühnel, K-U; Maurer, J; Messerschmidt, M; Rudek, B; Starodub, D; Thøgersen, J; Weidenspointner, G; White, T A; Stapelfeldt, H; Rolles, D; Chapman, H N; Küpper, J

    2014-01-01

    We give a detailed account of the theoretical analysis and the experimental results of an X-ray-diffraction experiment on quantum-state selected and strongly laser-aligned gas-phase ensembles of the prototypical large asymmetric rotor molecule 2,5-diiodobenzonitrile, performed at the Linac Coherent Light Source [Phys. Rev. Lett.112, 083002 (2014)]. This experiment is the first step toward coherent diffractive imaging of structures and structural dynamics of isolated molecules at atomic resolution, i.e., picometers and femtoseconds, using X-ray free-electron lasers. PMID:25415561

  3. 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.

  4. X-ray fluorescence tomography: Jacobin matrix and confidence of the reconstructed images

    NASA Astrophysics Data System (ADS)

    Nikolaev, Dmitry; Chukalina, Marina

    2015-02-01

    The goal of the X-ray Fluorescence Computed Tomography (XFCT) is to give the quantitative description of an object under investigation (sample) in terms of the element composition. However, light and heavy elements inside the object give different contribution to the attenuation of the X-ray probe and of the fluorescence. It leads to the elements got in the shadow area do not give any contribution to the registered spectrum. Iterative reconstruction procedures will try to set to zero the variables describing the element content in composition of corresponding unit volumes as these variables do not change system's condition number. Inversion of the XFCT Radon transform gives random values in these areas. To evaluate the confidence of the reconstructed images we first propose, in addition to the reconstructed images, to calculate a generalized image based on Jacobian matrix. This image highlights the areas of doubt in case if there are exist. In the work we have attempted to prove the advisability of such an approach. For this purpose, we analyzed in detail the process of tomographic projection formation.

  5. Preparing adherent cells for X-ray fluorescence imaging by chemical fixation.

    PubMed

    Finney, Lydia A; Jin, Qiaoling

    2015-01-01

    X-ray fluorescence imaging allows us to non-destructively measure the spatial distribution and concentration of multiple elements simultaneously over large or small sample areas. It has been applied in many areas of science, including materials science, geoscience, studying works of cultural heritage, and in chemical biology. In the case of chemical biology, for example, visualizing the metal distributions within cells allows us to study both naturally-occurring metal ions in the cells, as well as exogenously-introduced metals such as drugs and nanoparticles. Due to the fully hydrated nature of nearly all biological samples, cryo-fixation followed by imaging under cryogenic temperature represents the ideal imaging modality currently available. However, under the circumstances that such a combination is not easily accessible or practical, aldehyde based chemical fixation remains useful and sometimes inevitable. This article describes in as much detail as possible in the preparation of adherent mammalian cells by chemical fixation for X-ray fluorescent imaging. PMID:25867691

  6. A multichannel monolithic Ge detector system for fluorescence x-ray absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Bucher, J. J.; Allen, P. G.; Edelstein, N. M.; Shuh, D. K.; Madden, N. W.; Cork, C.; Luke, P.; Pehl, D.; Malone, D.

    1996-09-01

    The construction and performance characteristics of a monolithic quad-pixel Ge detector designed specifically for fluorescence x-ray absorption spectroscopy (XAS) at synchrotron radiation sources is described. The detector semiconductor element has an active surface area of 4.0 cm2 that is electrically separated into four 1.0 cm2 pixels, with little interfacial dead volume. The spatial response of the array demonstrates that cross-talk between adjacent pixels is less than 10% for 5.9-keV photons that fall within 0.5 mm of the pixel boundaries. The detector electronics system utilizes preamplifiers built at LBNL with commercial Tennelec Model TC 244 amplifiers. Employing an 55Fe test source (Mn K? , 5.9 keV), energy resolution of better than 200 eV is achieved with a 4 msec peaking time. At 0.5 msec peaking time, pulse pileup results in a 75% throughput efficiency for an incoming count rate of 100 kHz. Initial XAS fluorescence measurements at the beamline 4 wiggler end stations at SSRL show that the detector system has several advantages over commercially available x-ray spectrometers for low-concentration counting applications.

  7. Elemental concentration analysis in prostate tissues using total reflection X-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Leitão, R. G.; Palumbo, A.; Souza, P. A. V. R.; Pereira, G. R.; Canellas, C. G. L.; Anjos, M. J.; Nasciutti, L. E.; Lopes, R. T.

    2014-02-01

    Prostate cancer (PCa) currently represents the second most prevalent malignant neoplasia in men, representing 21% of all cancer cases. Benign Prostate Hyperplasia (BPH) is an illness prevailing in men above the age of 50, close to 90% after the age of 80. The prostate presents a high zinc concentration, about 10-fold higher than any other body tissue. In this work, samples of human prostate tissues with cancer, BPH and normal tissue were analyzed utilizing total reflection X-ray fluorescence spectroscopy using synchrotron radiation technique (SR-TXRF) to investigate the differences in the elemental concentrations in these tissues. SR-TXRF analyses were performed at the X-ray fluorescence beamline at Brazilian National Synchrotron Light Laboratory (LNLS), in Campinas, São Paulo. It was possible to determine the concentrations of the following elements: P, S, K, Ca, Fe, Cu, Zn and Rb. By using Mann-Whitney U test it was observed that almost all elements presented concentrations with significant differences (?=0.05) between the groups studied.

  8. Promising X-ray fluorescent tests for superconducting tunnel junction detector

    SciTech Connect

    Friedrich, Stephan; Robinson, Art

    2001-01-11

    Scientists in the Physical Biosciences Division of the Ernest Orlando Berkeley National Laboratory (Berkeley Lab) studying transition metals in proteins with fluorescence-detected L-edge absorption spectroscopy have found the measurements to be extremely challenging. The difficulty is that the metal centers are present in very dilute concentrations so that their weak fluorescence is often obscured by strong background signals from carbon and oxygen. To solve this problem, the Berkeley group has been working with researchers from the Advanced Detector Group at the Lawrence Livermore National Laboratory on an energy-dispersive superconducting tunnel junction x-ray detector. These devices in principle have the energy resolution needed to reveal the metal signal. The most recent results with the latest version of the detector on Beamline 4.0.1-2 at the Advanced Light Source (ALS) illustrate the promise of the cryogenic detector strategy not only for this application but also for spectroscopy of other types of dilute samples.

  9. Evaluation of chloride content in concrete by X-ray fluorescence

    SciTech Connect

    Proverbio, E. [Univ. of Rome La Sapienza (Italy)] [Univ. of Rome La Sapienza (Italy); Carassiti, F. [Third Univ. of Rome (Italy). Dept. of Mechanics and Automation] [Third Univ. of Rome (Italy). Dept. of Mechanics and Automation

    1997-08-01

    Determination of chloride content in concrete structures can be carried out by the X-ray fluorescence technique. However some problems affect measurement validity and limit the convenience of using XRF analysis when a limited number of determinations have to be performed. Measurements carried out on chloride contaminated concrete and mixtures of NaCl and concrete show the influence of distribution and grain size of chloride containing phase on analytical results. It is shown that chloride fluorescence intensity, at the same concentration level and at very low concentrations, is greatly reduced when chloride is present in the concrete matrix as NaCl salt instead of being dissolved in the concrete pore solution.

  10. Shedding new light on historical metal samples using micro-focused synchrotron X-ray fluorescence and spectroscopy

    Microsoft Academic Search

    D. Grolimund; M. Senn; M. Trottmann; M. Janousch; I. Bonhoure; A. M. Scheidegger; M. A. Marcus

    2004-01-01

    Synchrotron-based micro-X-ray fluorescence (micro-XRF) and micro-X-ray absorption spectroscopy (micro-XAS) were used in the present study to obtain spatially resolved micro-scale information on elemental composition, trace element distribution, chemical speciation and oxidation state and\\/or mineral phase distribution within historical iron artefacts dating from the Iron Age to early Medieval Times. Large area two-dimensional trace element distribution maps and oxidation state maps

  11. Atomic data for the ITER Core Imaging X-ray Spectrometer

    SciTech Connect

    Clementson, J; Beiersdorfer, P; Biedermann, C; Bitter, M; Delgado-Aparicio, L F; Graf, A; Gu, M F; Hill, K W; Barnsley, R

    2012-06-15

    The parameters of the ITER core plasmas will be measured using the Core Imaging X-ray Spectrometer (CIXS), a high-resolution crystal spectrometer focusing on the L-shell spectra of highly ionized tungsten atoms. In order to correctly infer the plasma properties accurate atomic data are required. Here, some aspects of the underlying physics are discussed using experimental data and theoretical predictions from modeling.

  12. Mechanism of Resonance-enhanced X-ray Multiple Ionization of Argon Atom in an XFEL Pulse

    NASA Astrophysics Data System (ADS)

    Young, Linda; Ho, Phay

    2014-05-01

    We present a new Monte Carlo rate equation (MCRE) approach to examine the inner-shell ionization dynamics of atoms in an intense x-ray free-electron laser (XFEL) pulse. In addition to photoionization, Auger decay and fluorescence processes, we include bound-to-bound transitions in the rate equation calculations. This computational tool allows us to account for ``hidden resonances'' unveiled in high charge states of atom in XFEL pulse. Using our MCRE approach, we investigated the ionization dynamics of Argon atom exposed to an 480-eV XFEL pulse. At this photon energy, it is not energetically allowed to produce Ar ions with charge 10 + and higher via direct one-photon L-shell ionization. Rather, we found that the resonance-enhanced x-ray multiple ionization (REXMI) pathways play a dominant role in producing these highly charged ions. Our calculated results agree with the measured Ar ion yield data. More importantly, we account for the pulse-duration dependence of experimental ion yield data and identify the responsible REXMI pathways where excitation of multiple electrons into outer valence and Rydberg orbitals are followed by autoionization. Supported by the Chemical Sciences, Geosciences, and Biosciences Di- vision, Office of Basic Energy Sciences, Office of Science, US Dept of Energy, Contract DE-AC02-06CH11357.

  13. Application of Synchrotron Radiation X-Ray Fluorescence (?-SRXF) and X-Ray Microanalysis (SEM\\/EDX) for the Quantitative and Qualitative Evaluation of Trace Element Accumulation in Woody Plants

    Microsoft Academic Search

    Nelson Marmiroli; Elena Maestri; Giovanni Antonioli; Carmelina Conte; Paolo Monciardini; Marta Marmiroli; Claudio Mucchino

    1999-01-01

    Different analytical techniques were applied to describe the localization of lead and chromium in the tissues of walnut (Juglans regia) and maple (Acer saccharinum) plants exposed to soils that had been artificially contaminated with heavy metals. Two X-ray-based techniques, synchrotron radiation X-ray fluorescence (?-SRXF) and X-ray microanalysis (SEM\\/EDX), were utilized in association with induced coupled plasma optical emission spectrometry (ICP-OES).

  14. O I fluorescent line contamination in soft X-ray diffuse background obtained with Suzaku/XIS

    NASA Astrophysics Data System (ADS)

    Sekiya, Norio; Yamasaki, Noriko Y.; Mitsuda, Kazuhisa; Takei, Yoh

    2014-04-01

    The quantitative measurement of O VII line intensity is a powerful method for understanding the soft X-ray diffuse background. By systematically analyzing the O VII line intensity in 145 high-latitude Suzaku/XIS observations, the flux of O I fluorescent line in the XIS spectrum, contaminating the O VII line, is found to have an increasing trend with time especially after 2011. For these observations, the O VII line intensity would be overestimated unless taking into consideration the O I fluorescent line contamination. Since the O I line emission originates from solar X-rays, this increase suggests that the flux of incident solar X-rays at the O I fluorescence energy tend to be larger than that in the early phase of Suzaku observations (2005-2010).

  15. Optimizing the operation of a high resolution vertical Johann spectrometer using a high energy fluorescer x-ray sourcea)

    NASA Astrophysics Data System (ADS)

    Haugh, Michael; Stewart, Richard

    2010-10-01

    This paper describes the operation and testing for a vertical Johann spectrometer (VJS) operating in the 13 keV range. The spectrometer is designed to use thin curved mica crystals or thick germanium crystals. The VJS must have a resolution of E /?E=3000 or better to measure the Doppler broadening of highly ionized krypton and operate at a small x-ray angle in order to be used as a diagnostic in a laser plasma target chamber. The VJS was aligned, tested, and optimized using a fluorescer type high energy x-ray (HEX) source located at National Security Technologies (NSTec), LLC, in Livermore, CA. The HEX uses a 160 kV x-ray tube to excite fluorescence from various targets. Both rubidium and bismuth fluorescers were used for this effort. This presentation describes the NSTec HEX system and the methods used to optimize and characterize the VJS performance.

  16. Optimizing the Operation of a Vertical Johann Spectrometer Using a High Energy Fluorescer X-ray Source

    SciTech Connect

    Haugh, Michael [NSTec; Stewart, Richard [LLNL

    2010-10-01

    This paper describes the operation and testing for a Vertical Johann Spectrometer (VJS) operating in the 13 keV range. The spectrometer is designed to use thin curved mica crystals or thick germanium crystals. The VJS must have a resolution E/?E=3000 or better to measure Doppler broadening of highly ionized krypton and operate at a small X-ray angle in order to be used as a diagnostic in a laser plasma target chamber. The VJS was aligned, tested, and optimized using a fluorescer type high energy X-ray (HEX) source located at National Security Technologies, LLC (NSTec), in Livermore, California. The HEX uses a 160 kV X-ray tube to excite fluorescence from various targets. Both rubidium and bismuth fluorescers were used for this effort. This presentation describes the NSTec HEX system and the methods used to optimize and characterize the VJS performance.

  17. Trace Element Mapping of a Biological Specimen by a Full-Field X-ray Fluorescence Imaging Microscope with a Wolter Mirror

    SciTech Connect

    Hoshino, Masato; Yamada, Norimitsu; Ishino, Toyoaki; Namiki, Takashi; Watanabe, Norio; Aoki, Sadao [Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8573 (Japan)

    2007-01-19

    A full-field X-ray fluorescence imaging microscope with a Wolter mirror was applied to the element mapping of alfalfa seeds. The X-ray fluorescence microscope was built at the Photon Factory BL3C2 (KEK). X-ray fluorescence images of several growing stages of the alfalfa seeds were obtained. X-ray fluorescence energy spectra were measured with either a solid state detector or a CCD photon counting method. The element distributions of iron and zinc which were included in the seeds were obtained using a photon counting method.

  18. The neoplastic transformation potential of mammography X rays and atomic bomb spectrum radiation.

    PubMed

    Heyes, G J; Mill, A J

    2004-08-01

    Considerable controversy currently exists regarding the biological effectiveness of 29 kVp X rays which are used for mammography screening. This issue must be resolved to enable proper evaluation of radiation risks from breast screening. Here a definitive assessment of the biological effectiveness of 29 kVp X rays compared to the quality of radiation to which the atomic bomb survivors were exposed is presented for the first time. The standard radiation sources used were (a) an atomic bomb simulation spectrum and (b) 2.2 MeV electrons from a strontium-90/yttrium-90 (90Sr/90Y) radioactive source. The biological end point used was neoplastic transformation in vitro in CGL1 (HeLa x human fibroblast hybrid) cells. No significant difference was observed for the biological effectiveness of the two high-energy sources for neoplastic transformation. A limiting relative biological effectiveness (RBE(M)) of 4.42 +/- 2.02 was observed for neoplastic transformation by 29 kVp X rays compared to these two sources. This compares with values of 4.67 +/- 3.93 calculated from previously published data and 3.58 +/- 1.77 when the reference radiation was 200 and 220 kVp X rays. This suggests that the risks associated with mammography screening may be approximately five times higher than previously assumed and that the risk-benefit relationship of mammography exposures may need to be re-examined. PMID:15387138

  19. LETTER doi:10.1038/nature10721 Atomic inner-shell X-ray laser at 1.46 nanometres

    E-print Network

    Rocca, Jorge J.

    -ray free-electron laser Nina Rohringer1 {, Duncan Ryan2 , Richard A. London1 , Michael Purvis2 , Felicie­7 . The introduction of X-ray free-electron lasers8­10 makes it possible to pump new atomic X-ray lasers11 and driven by rapid K-shell photo-ionization using pulses from an X-ray free-electron laser. We established

  20. Simulated 'On-Line' Wear Metal Analysis of Lubricating Oils by X-Ray Fluorescence Spectroscopy

    NASA Technical Reports Server (NTRS)

    Kelliher, Warren C.; Partos, Richard D.; Nelson, Irina

    1996-01-01

    The objective of this project was to assess the sensitivity of X-ray Fluorescence Spectroscopy (XFS) for quantitative evaluation of metal particle content in engine oil suspensions and the feasibility of real-time, dynamic wear metal analysis. The study was focused on iron as the majority wear metal component. Variable parameters were: particle size, particle concentration and oil velocity. A commercial XFS spectrometer equipped with interchangeable static/dynamic (flow cell) sample chambers was used. XFS spectra were recorded for solutions of Fe-organometallic standard and for a series of DTE oil suspensions of high purity spherical iron particles of 2g, 4g, and 8g diameter, at concentrations from 5 ppm to 5,000 ppm. Real contaminated oil samples from Langley Air Force Base aircraft engines and NASA Langley Research Center wind tunnels were also analyzed. The experimental data conform the reliability of XFS as the analytical method of choice for this project. Intrinsic inadequacies of the instrument for precise analytic work at low metal concentrations were identified as being related to the particular x-ray beam definition, system geometry, and flow-cell materials selection. This work supports a proposal for the design, construction and testing of a conceptually new, miniature XFS spectrometer with superior performance, dedicated to on-line, real-time monitoring of lubricating oils in operating engines. Innovative design solutions include focalization of the incident x-ray beam, non-metal sample chamber, and miniaturization of the overall assembly. The instrument would contribute to prevention of catastrophic engine failures. A proposal for two-year funding has been presented to NASA Langley Research Center Internal Operation Group (IOG) Management, to continue the effort begun by this summer's project.

  1. Medieval glass from the Cathedral in Paderborn: a comparative study using X-ray absorption spectroscopy, X-ray fluorescence, and inductively coupled laser ablation mass spectrometry

    NASA Astrophysics Data System (ADS)

    Hormes, J.; Roy, A.; Bovenkamp, G.-L.; Simon, K.; Kim, C.-Y.; Börste, N.; Gai, S.

    2013-04-01

    We have investigated four stained glass samples recovered from an archaeological excavation at the Cathedral in Paderborn (Germany) between 1978 and 1980. On two of the samples there are parts of paintings. Concentrations of major elements were determined using two independent techniques: LA-ICP-MS (a UV laser ablation microsampler combined with an inductively coupled plasma mass spectrometer) and synchrotron radiation X-ray excited X-ray fluorescence (SR-XRF). The SR-XRF data were quantified by using the program package PyMCA developed by the software group of the ESRF in Grenoble. Significant differences were found between the concentrations determined by the two techniques that can be explained by concentration gradients near the surface of the glasses caused, for example, by corrosion/leaching processes and the different surface sensitivities of the applied techniques. For several of the elements that were detected in the glass and in the colour pigments used for the paintings X-ray absorption near edge structure (XANES) spectra were recorded in order to determine the chemical speciation of the elements of interest. As was expected, most elements in the glass were found as oxides in their most stable form. Two notable exceptions were observed: titanium was not found as rutile—the most stable form of TiO2—but in the form of anatase, and lead was not found in one defined chemical state but as a complex mixture of oxide, sulphate, and other compounds.

  2. Real-Time Studies of Gallium Adsorption and Desorption Kinetics by Grazing-Incidence Small-Angle X-ray Scattering and X-ray Fluorescence

    SciTech Connect

    Wang, Y.; Ozcan, A; Ludwig, K; Bhattacharyya, A

    2008-01-01

    Gallium adsorption and desorption on c-plane sapphire has been studied by real-time grazing incidence small-angle x-ray scattering and x-ray fluorescence as a function of substrate temperature (680-740 C) and Ga flux. The x-ray techniques monitor the surface morphology evolution and amount of Ga on the surface. During deposition, nanodroplets of liquid Ga are observed to form on the surface and coarsen. The growth of droplet size during continuous deposition follows dynamical scaling, in agreement with expectations from theory and simulations which include deposition-induced droplet coalescence. However, observation of continued droplet distance scale coarsening during desorption points to the necessity of including further physical processes in the modeling. The desorption rate at different substrate temperatures gives the activation energy of Ga desorption as 2.7 eV, comparable to measured activation energies for desorption from Ga droplets on other substrates and to the Ga heat of vaporization.

  3. Real-time studies of gallium adsorption and desorption kinetics on sapphire (0001) by grazing incidence small-angle x-ray scattering and x-ray fluorescence

    SciTech Connect

    Wang Yiyi; Oezcan, Ahmet S.; Ludwig, Karl F. [Physics Department, Boston University, Boston, Massachusetts 02215 (United States); Bhattacharyya, Anirban [Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts 02215 (United States)

    2008-05-15

    Gallium adsorption and desorption on c-plane sapphire has been studied by real-time grazing incidence small-angle x-ray scattering and x-ray fluorescence as a function of substrate temperature (680-740 deg. C) and Ga flux. The x-ray techniques monitor the surface morphology evolution and amount of Ga on the surface. During deposition, nanodroplets of liquid Ga are observed to form on the surface and coarsen. The growth of droplet size during continuous deposition follows dynamical scaling, in agreement with expectations from theory and simulations which include deposition-induced droplet coalescence. However, observation of continued droplet distance scale coarsening during desorption points to the necessity of including further physical processes in the modeling. The desorption rate at different substrate temperatures gives the activation energy of Ga desorption as 2.7 eV, comparable to measured activation energies for desorption from Ga droplets on other substrates and to the Ga heat of vaporization.

  4. Detection of Fingerprints Based on Elemental Composition Using Micro-X-Ray Fluorescence.

    SciTech Connect

    Worley, C. G. (Christopher G.); Wiltshire, S. (Sara); Miller, T. C. (Thomasin C.); Havrilla, G. J. (George J.); Majidi, V. (Vahid)

    2005-01-01

    A method was developed to detect fingerprints using a technique known as micro-X-ray fluorescence. The traditional method of detecting fingerprints involves treating the sample with certain powders, liquids, or vapors to add color to the fingerprint so that it can be easily seen and photographed for forensic purposes. This is known as contrast enhancement, and a multitude of chemical processing methods have been developed in the past century to render fingerprints visible. However, fingerprints present on certain substances such as fibrous papers and textiles, wood, leather, plastic, adhesives, and human skin can sometimes be difficult to detect by contrast enhancement. Children's fingerprints are also difficult to detect due to the absence of sebum on their skin, and detection of prints left on certain colored backgrounds can sometimes be problematic. Micro-X-ray fluorescence (MXRF) was studied here as a method to detect fingerprints based on chemical elements present in fingerprint residue. For example, salts such as sodium chloride and potassium chloride excreted in sweat are sometimes present in detectable quantities in fingerprints. We demonstrated that MXRF can be used to detect this sodium, potassium, and chlorine from such salts. Furthermore, using MXRF, each of these elements (and many other elements if present) can be detected as a function of location on a surface, so we were able to 'see' a fingerprint because these salts are deposited mainly along the patterns present in a fingerprint (traditionally called friction ridges in forensic science). MXRF is not a panacea for detecting all fingerprints; some prints will not contain enough detectable material to be 'seen'; however, determining an effective means of coloring a fingerprint with traditional contrast enhancement methods can sometimes be an arduous process with limited success. Thus, MXRF offers a possible alternative for detecting fingerprints, and it does not require any additional chemical treatment steps which can be time consuming and permanently alter the sample. Additionally, MXRF is noninvasive, so a fingerprint analyzed by this method is left pristine for examination by other methods (eg. DNA extraction). To the best of the author's knowledge, no studies have been published to date concerning the detection of fingerprints by micro-X-ray fluorescence. Some studies have been published in which other spectroscopic methods were employed to examine the chemical composition of fingerprints (eg. IR, SEM/EDX, and Auger), but very few papers discuss the actual detection and imaging of a complete fingerprint by any spectroscopic method. Thus, this work is unique.

  5. Determination of carbon in natural freshwater biofilms with total reflection X-ray fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Óvári, M.; Streli, C.; Wobrauschek, P.; Záray, Gy.

    2009-08-01

    There is a growing interest in determination of low Z elements, i.e., carbon to phosphorus, in biological samples. Total reflection X-ray fluorescence spectrometry (TXRF) has been already established as suitable trace element analytical method with low sample demand and quite good quantification limits. Recently, the determinable element range was extended towards Z = 6 (carbon). Biofilms can be used for biomonioring purposes in the aquatic environment. Besides the trace metals, especially the determination of the carbon content is important for the better understanding of the early stage of biofilm formation. For this, an ATI low Z spectrometer equipped with Cr-anode X-ray tube, multilayer monochromator, vacuum chamber, and a Si(Li) detector with ultra thin window was used. Biofilms were grown on two different artificial supports (granite and plexiglass), freeze dried, suspended in high purity water and analyzed. As an internal standard the natural titanium content of the biofilms was used. The accuracy of the method was checked by total carbon measurement using a combusting carbon analyzer.

  6. Total Reflection X-ray Fluorescence attachment module modified for analysis in vacuum

    NASA Astrophysics Data System (ADS)

    Wobrauschek, P.; Streli, C.; Kregsamer, P.; Meirer, F.; Jokubonis, C.; Markowicz, A.; Wegrzynek, D.; Chinea-Cano, E.

    2008-12-01

    Based on the design of the low cost Total Reflection X-Ray Fluorescence attachment module available since 1986 from Atominstitut (WOBRAUSCHEK-module) which can be attached to existing X-ray equipment, a new version was developed which allows the analysis of samples in vacuum. This design was in particular possible as the Peltier cooled light weight Silicon Drift Detector is following all adjustment procedures for total reflection as angle rotation and linear motion. The detector is mounted through a vacuum feed and O-ring tightening to the small vacuum chamber. The standard 30 mm round quartz, Si-wafer or Plexiglas reflectors are used to carry the samples. The reflectors are placed on the reference plane with the dried sample down looking facing in about 0.5 mm distance the up looking detector window. The reflectors are resting on 3 steel balls defining precisely the reference plane for the adjustment procedure. As the rotation axis of the module is in the plane of the reflector surface, angle dependent experiments can be made to distinguish between film and particulate type contamination of samples. Operating with a Mo anode at 50 kV and 40 mA with a closely attached multilayer monochromator and using a 10 mm 2 KETEK silicon drift detector with 8 ?m Be window, a sensitivity of 70 cps/ng for Rb was measured and detection limits of 2 pg were obtained.

  7. Micro x-ray fluorescence as a high throughput screening method for metal chelating compounds

    NASA Astrophysics Data System (ADS)

    Minogue, Edel M.; Havrilla, George J.; Taylor, Tammy P.; Burrell, Anthony K.; Warner, Benjamin P.

    2005-06-01

    Micro X-ray Fluorescence (MXRF) has proven to be a powerful tool in the rapid and quantitative means of screening oliogpeptides. MXRF is a non-destructive method of analysis, which can detect elemental composition of a sample by measuring its characteristic X-ray emission wavelengths or energies. An effective high throughput screening technique is described for the rapid screening of bead-based libraries by MXRF in order to identify suitable chelating agents that will bind metals found in radioactive dispersive devices. It is a sensitive technique which in conjunction with the wide range of chemistry inherent in peptide libraries (e.g. varying charge, length, hydrophobicity, aromaticity etc.), provides a rapid and quantitative means for screening chelator-ion binding. The method involves the selection of a suitable library of ligands; in this case it is a bead-based library of peptides. The library is exposed to the cation of interest and immobilized on to a microarray. The array is then analyzed by MXRF enabling rapid identification of chelating agents. This enables the screening of approximately 27,500 sequences per day. Initial experiments carried out successfully identified sequences that are selective for Co under certain binding conditions. This involved the screening of 8,400 sequences in adverse environmental conditions containing possible interferences (e.g. Ca, Fe, Al, Cs, Ir), which could be encountered in our application.

  8. Synchrotron-based X-ray fluorescence imaging and elemental mapping from biological samples

    SciTech Connect

    D Rao; M Swapna; R Cesareo; A Brunetti; T Akatsuka; T Yuasa; T Takeda; G Gigante

    2011-12-31

    The present study utilized the new hard X-ray microspectroscopy beamline facility, X27A, available at NSLS, BNL, USA, for elemental mapping. This facility provided the primary beam in a small spot of the order of {approx}10 {mu}m, for focussing. With this spatial resolution and high flux throughput, the synchrotron-based X-ray fluorescent intensities for Mn, Fe, Zn, Cr, Ti and Cu were measured using a liquid-nitrogen-cooled 13-element energy-dispersive high-purity germanium detector. The sample is scanned in a 'step-and-repeat' mode for fast elemental mapping measurements and generated elemental maps at 8, 10 and 12 keV, from a small animal shell (snail). The accumulated trace elements, from these biological samples, in small areas have been identified. Analysis of the small areas will be better suited to establish the physiology of metals in specific structures like small animal shell and the distribution of other elements.

  9. X-ray induced fluorescence measurement of segregation in a DyI3-Hg metal-halide lamp.

    SciTech Connect

    Nimalasuriya , T.; Curry, J. J.; Sansonetti, C. J.; Ridderhof, E. J.; Shastri, S. D.; Filkweert, A. J.; Stoffels, W. W.; Haverlag, M.; van der Mullen, J. J.; Eindhoven Univ. of Technology; NIST

    2007-05-07

    Segregation of elemental Dy in a DyI{sub 3}-Hg metal-halide high-intensity discharge lamp has been observed with x-ray induced fluorescence. Significant radial and axial Dy segregation are seen, with the axial segregation characterized by a Fischer parameter value of {lambda} = 0.215 {+-} 0.002 mm{sup -1}. This is within 7% of the value ({lambda} = 0.20 {+-} 0.01 mm{sup -1}) obtained by Flikweert et al based on laser absorption by neutral Dy atoms. Elemental I is seen to exhibit considerably less axial and radial segregation. Some aspects of the observed radial segregation are compatible with a simplified fluid picture describing two main transition regions in the radial coordinate. The first transition occurs in the region where DyI{sub 3} molecules are in equilibrium with neutral Dy atoms. The second transition occurs where neutral Dy atoms are in equilibrium with ionized Dy. These measurements are part of a larger study on segregation in metal-halide lamps under a variety of conditions.

  10. Rayleigh x-ray scattering from many-electron atoms and ions

    NASA Astrophysics Data System (ADS)

    Surzhykov, A.; Yerokhin, V. A.; Stöhlker, Th; Fritzsche, S.

    2015-07-01

    A theoretical analysis is presented for the elastic Rayleigh scattering of x-rays by many-electron atoms and ions. Special emphasis is placed on the angular distribution and linear polarization of the scattered photons for the case when the incident light is completely (linearly) polarized. Based on second-order perturbation theory and the independent particle approximation, we found that the Rayleigh angular distribution is strongly affected by the charge state and shell structure of the target ions or atoms. This effect can be observed experimentally at modern synchrotron facilities and might provide further insight into the structure of heavy atomic systems.

  11. Atomic structure of Au-nanoparticles on silica support by X-ray PDF study

    SciTech Connect

    Dmowski, W. [University of Tennessee, Knoxville (UTK); Yin, Hongfeng [ORNL; Dai, Sheng [ORNL; Overbury, Steven {Steve} H [ORNL; Egami, T. [University of Tennessee, Knoxville (UTK)

    2010-01-01

    We investigated the atomic structure of gold nanoparticles with an average size of 5 nm in diameter, supported by silica. We used high-energy X-ray diffraction and the atomic pair distribution function (PDF) to probe the local atomic structure. Measurements were performed from 25 to 950 C. The structure is approximately fcc in average but exhibits small distortions. The structural distortion increases with the temperature and could be related to the catalytic activity of gold nanoparticles. Above 425 C, rapid particle growth and coalescence were observed.

  12. Atomic Structure of Au Nanoparticles on a Silica Support by an X-ray PDF Study

    SciTech Connect

    Dmowski, Wojtek; Yin, Hongfeng; Dai, Sheng; Overbury, Steven H.; Egami, Takeshi (Tennessee-K); (ORNL)

    2010-05-04

    We investigated the atomic structure of gold nanoparticles with an average size of {approx}5 nm in diameter, supported by silica. We used high-energy X-ray diffraction and the atomic pair distribution function (PDF) to probe the local atomic structure. Measurements were performed from 25 to 950 C. The structure is approximately fcc in average but exhibits small distortions. The structural distortion increases with the temperature and could be related to the catalytic activity of gold nanoparticles. Above 425 C, rapid particle growth and coalescence were observed.

  13. Grazing angle X-ray fluorescence from periodic structures on silicon and silica surfaces

    NASA Astrophysics Data System (ADS)

    Nowak, S. H.; Bana?, D.; B?chucki, W.; Cao, W.; Dousse, J.-Cl.; Hönicke, P.; Hoszowska, J.; Jab?o?ski, ?.; Kayser, Y.; Kubala-Kuku?, A.; Pajek, M.; Reinhardt, F.; Savu, A. V.; Szlachetko, J.

    2014-08-01

    Various 3-dimensional nano-scaled periodic structures with different configurations and periods deposited on the surface of silicon and silica substrates were investigated by means of the grazing incidence and grazing emission X-ray fluorescence techniques. Apart from the characteristics which are typical for particle- and layer-like samples, the measured angular intensity profiles show additional periodicity-related features. The latter could be explained by a novel theoretical approach based on simple geometrical optics (GO) considerations. The new GO-based calculations were found to yield results in good agreement with experiment, also in cases where other theoretical approaches are not valid, e.g., periodic particle distributions with an increased surface coverage.

  14. Development of a combined portable x-ray fluorescence and Raman spectrometer for in situ analysis.

    PubMed

    Guerra, M; Longelin, S; Pessanha, S; Manso, M; Carvalho, M L

    2014-06-01

    In this work, we have built a portable X-ray fluorescence (XRF) spectrometer in a planar configuration coupled to a Raman head and a digital optical microscope, for in situ analysis. Several geometries for the XRF apparatus and digital microscope are possible in order to overcome spatial constraints and provide better measurement conditions. With this combined spectrometer, we are now able to perform XRF and Raman measurements in the same point without the need for sample collection, which can be crucial when dealing with cultural heritage objects, as well as forensic analysis. We show the capabilities of the spectrometer by measuring several standard reference materials, as well as other samples usually encountered in cultural heritage, geological, as well as biomedical studies. PMID:24985805

  15. The use of a portable total reflection X-ray fluorescence spectrometer for field investigation

    NASA Astrophysics Data System (ADS)

    Mages, Margarete; Woelfl, Stefan; Óvári, Mihály; Tümpling jun, Wolf v.

    2003-12-01

    A newly developed, portable total reflection X-ray fluorescence (TXRF) spectrometer was tested during a field campaign on Chilean lakes and a German river in January 2002. The field measurements were compared with laboratory measurements carried out on a stationary instrument in the German laboratory. For method validation certified reference material (NIST SRM 1640 Trace elements in natural water) and water samples from different freshwater sources were analyzed with both techniques and evaluated statistically. Based on these preliminary results, it could be concluded that the portable TXRF is a useful technique for the quantitative elemental screening of freshwater samples during field campaigns. Future tests with biological samples (e.g. biofilms and zooplankton), and suspended matter will provide information about the suitability of the portable TXRF for these materials.

  16. 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.

  17. Energy-dispersive X-ray fluorescence analysis as a rapid method for identifying tephras

    NASA Astrophysics Data System (ADS)

    Cormie, A. B.; Nelson, D. E.

    1983-03-01

    The use of energy-dispersive X-ray fluorescence analysis (XES) for the routine identification of three tephras (Mazama, Bridge River, Mount St. Helens Yn) commonly found in archeological sites in British Columbia has been investigated. Researchers have often assumed that chemical analysis of bulk samples of glass separates would be hampered by contamination and weathering effects. Our results indicate that XES of bulk glass separates provides a very reliable method for rapidly identifying the three tephras in question, even with a very simple sample preparation. This should enable persons not skilled in geology or in tephrochronology to collect and to identify samples of these tephras. Finally, as a part of the study, similar measurements were made on the separated glass portions of these three tephras and of three others (Glacier Peak B and G, White River) from northwest North America. The results suggest that this method may provide tephrochronologists with a useful additional tool for studying tephras in other regions.

  18. Performance of a Borehole X-ray Fluorescence Spectrometer for Planetary Exploration

    NASA Technical Reports Server (NTRS)

    Kelliher, Warren C.; Carlberg, Ingrid A.; Elam, W. T.; Willard-Schmoe, Ella

    2008-01-01

    We have designed and constructed a borehole X-ray Fluorescence Spectrometer (XRFS) as part of the Mars Subsurface Access program [1]. It can be used to determine the composition of the Mars regolith at various depths by insertion into a pre-drilled borehole. The primary requirements and performance metrics for the instrument are to obtain parts-per-million (ppm) lower limits of detection over a wide range of elements in the periodic table (Magnesium to Lead). Power consumption during data collection was also measured. The prototype instrument is complete and preliminary testing has been performed. Terrestrial soil Standard Reference Materials were used as the test samples. Detection limits were about 10 weight ppm for most elements, with light elements being higher, up to 1.4 weight percent for magnesium. Power consumption (excluding ground support components) was 12 watts.

  19. Measuring iron in the brain using quantitative susceptibility mapping and X-ray fluorescence imaging

    PubMed Central

    Zheng, Weili; Nichol, Helen; Liu, Saifeng; Cheng, Yu-Chung N.; Haacke, E. Mark

    2013-01-01

    Measuring iron content in the brain has important implications for a number of neurodegenerative diseases. Quantitative susceptibility mapping (QSM), derived from magnetic resonance images, has been used to measure total iron content in vivo and in post mortem brain. In this paper, we show how magnetic susceptibility from QSM correlates with total iron content measured by X-ray fluorescence (XRF) imaging and by inductively coupled plasma mass spectrometry (ICPMS). The relationship between susceptibility and ferritin iron was estimated at 1.10 ± 0.08 ppb susceptibility per ?g iron/g wet tissue, similar to that of iron in fixed (frozen/thawed) cadaveric brain and previously published data from unfixed brains. We conclude that magnetic susceptibility can provide a direct and reliable quantitative measurement of iron content and that it can be used clinically at least in regions with high iron content. PMID:23591072

  20. 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.

  1. Remote analyses of highly radioactive samples by x-ray fluorescence

    SciTech Connect

    Warrant, R.W.; Shurtliff, R.M.; Haskell, K.J.; Ryder, W.A.

    1991-09-11

    The Idaho Chemical Processing Plant (ICPP) is a multipurpose nuclear fuel and waste processing facility located at the Idaho National Engineering Laboratory (INEL) near Idaho Falls, Idaho. The plant is presently operated for the Department of Energy (DOE) by a subsidiary of Westinghouse Electric Company, Westinghouse Idaho Nuclear Company (WINCO). The facility receives and processes a large variety of reactor fuel types. The analysis of spent nuclear fuel reprocessing streams causes some unique problems for the analytical chemist. The major problems are the high levels of radioactivity, the complex solution of fuel components, fission products, dissolved cladding, and dissolver solutions as well as the need for rapid results. For the analysis of the heavy metals in these complex radioactive samples, the technique of wavelength dispersive X-ray fluorescence offers some distinct advantages. The method is specific, highly automated, and the sample requires minimum preparation.

  2. Application of x-ray fluorescence analysis to investigation of the composition of gunshot residues

    NASA Astrophysics Data System (ADS)

    Kazimirov, V. I.; Zorin, A. D.; Zanozina, V. F.

    2006-05-01

    We have used x-ray fluorescence analysis to study the elemental composition of gunshot residues from smooth-bore and rifled-bore guns. We have established that it is possible to differentiate between types of projectiles (jacketed/lead), types of primers (corrosive/noncorrosive), and types of propellant powders (black/smokeless) by analysis of the elemental composition of the gunshot residues. We have shown that the mercury content in gunshot residues on the surface of the object carrying the residues steadily decreases as storage time increases. Despite this fact, mercury can be preserved as a component of gunshot residues on the object (cotton cloth) under room conditions for more than 45 days.

  3. Petrographic, mineralogic, and x-ray fluorescence analysis of lunar igneous-type rocks and spherules.

    PubMed

    Brown, G M; Emeleus, C H; Holland, J G; Phillips, R

    1970-01-30

    Three lunar rocks show almost identical mineralogy but grain sizes that vary from basaltic to gabbroic. Clinopyroxene is zoned from augite to subcalcic ferroaugite compositions and is accompanied by decrease in Cr, Al, and Ti. Plagioclase is zoned from 93 to 78 percent anorthite. Olivine (68 percent forsterite) is present in one rock and apatite is rare. Cristobalite, ilmenite with Ti-rich lamellae, ulvöspinel (often Cr-rich), troilite, and kamacite are low in trace elements. Glassy spherules are of basaltic or feldspathic (92 percent anorthite) composition but contain abundant iron spheres of taenite composition (13 percent Ni). Four rock analyses by x-ray fluorescence show affinity with terrestrial basalts but with anomalous amounts of Ti, Na, Cr, Zr, Y, Rb, Nb, Ni, Cu, and Zn. PMID:17781511

  4. [Analysis of heavy metal in soil with portable X-ray fluorescence spectrometry].

    PubMed

    Han, Ping; Wang, Ji-hua; Lu, An-xiang; Ma, Zhi-hong; Pan, Li-gang

    2012-03-01

    The concentrations of main heavy metal pollutants (Cu, Zn, Pb, Cr and As) in soil were tested by NITON XL3 600 portable X-ray fluorescence spectrometry (PXRF). The results showed that the minimum? detection limits for elements Cu, Zn, Pb, Cr and As were 23.96, 11.69, 8.58, 19.23, 6.24 mg x kg(-1), respectively. The soil composition standard material GSS-5 was detected by PXRF for 5 replicate measurements, The accuracy was 96%-102% and relative standard deviations (RSD) was 1.0%-7.6%. In term of field situ testing, RSD was less than 20%, and accuracy was 55%-119%. The performance was assessed by laboratory testing and field situ detection, and the results indicated that PXRF is effective for rapid, quantitative monitoring of soil metal contamination. PMID:22582662

  5. Determination of thorium in geological materials by x-ray fluorescence spectrometry after anion exchange extraction

    SciTech Connect

    Roelandts, I.

    1983-08-01

    The exchange capacity of the resin was determined to be 1 m equiv of Th/g dry resin. Synthetic calibration standards of thorium were prepared over a large concentration range, for use as an independent method of calibration. The advantages and disadvantages of direct x-ray fluorescence analysis are discussed. The lower limit of detection has been calculated according to Currie's convention and was found to be equal to 13 ..mu..g of Th/250 mg of resin, sufficient for the range of concentrations found in Th bearing minerals and ores. Results using Canadian syenite rocks and a suite of South African reference minerals show that the proposed method appears to be relatively precise and accurate for exploration geochemistry. 1 figure, 2 tables.

  6. Portable X-ray Fluorescence Spectrometry for the analyses of Cultural Heritage

    NASA Astrophysics Data System (ADS)

    Ridolfi, S.

    2012-07-01

    Field Portable Energy Dispersive X Ray Fluorescence (FP-EDXRF) is particularly useful to analyze works of art, mainly because of his noninvasive and multielemental capability. In many situations FP-EDXRF is the only non invasive technique that can be realistically used to gain some information about the chemical composition of precious and unique objects. Many kind of works, such as paintings, bronzes, precious metals alloys, inks, stones, stamps and more can be studied using a field portable EDXRF system. This manuscript highlights some drawbacks that have to be kept in mind to fulfill a valid measurement such as the need for other backup methods to support portable XRF results or the problem of the non-homogeneity of the sample. This manuscript will also present three examples to demonstrate the usefulness of FP-EDXRF with paintings on canvas, ancient bronzes and sulfur surface analyses.

  7. X-ray spectra of Hercules X-1. I - Iron line fluorescence from a subrelativistic shell

    NASA Technical Reports Server (NTRS)

    Pravdo, S. H.; Becker, R. H.; Boldt, E. A.; Holt, S. S.; Serlemitsos, P. J.; Swank, J. H.

    1977-01-01

    The X-ray spectrum of Her X-1 was observed in the energy range from 2 to 24 keV from August 29 to September 3, 1975. Emission features are observed near the K-alpha iron-line energy which exhibit both broadening and a double line structure. The total luminosity in these features is about 4 by 10 to the 35th power ergs/s. Iron line fluorescence from an opaque cool (not exceeding 1 million K) shell of material at the Alfven surface provides the necessary luminosity in this feature. The double line structure and the line energy width can be due to Doppler shifts if the shell is forced to corotate with the pulsar at a radius of at least 800 million cm. Implications of this model regarding physical conditions near Her X-1 are discussed.

  8. Possible use of pattern recognition for the analysis of Mars rover X-ray fluorescence spectra

    NASA Technical Reports Server (NTRS)

    Yin, Lo I; Trombka, Jacob I.; Seltzer, Stephen M.; Johnson, Robert G.; Philpotts, John A.

    1989-01-01

    On the Mars rover sample-return mission, the rover vehicle will collect and select samples from different locations on the Martian surface to be brought back to earth for laboratory studies. It is anticipated that an in situ energy-dispersive X-ray fluorescence (XRF) spectrometer will be on board the rover. On such a mission, sample selection is of higher priority than in situ quantitative chemical anlaysis. With this in mind, a pattern recognition technique is proposed as a simple, direct, and speedy alternative to detailed chemical analysis of the XRF spectra. The validity and efficacy of the pattern recognition technique are demonstrated by the analyses of laboratory XRF spectra obtained from a series of geological samples, in the form both of standardized pressed pellets and as unprepared rocks. It is found that pattern recognition techniques applied to the raw XRF spectra can provide for the same discrimination among samples as a knowledge of their actual chemical composition.

  9. X-ray spectra of Hercules X-1. 1: Iron line fluorescence from a subrelativistic shell

    NASA Technical Reports Server (NTRS)

    Pravdo, S. H.; Becker, R. H.; Boldt, E. A.; Holt, S. S.; Serlemitsos, P. J.; Swank, J. H.

    1977-01-01

    The X-ray spectrum of Hercules X-1 was observed in the energy range 2-24 keV from August 29 to September 3, 1975. A broad iron line feature is observed in the normal high state spectrum. The line equivalent width is given along with its full-width-half-maximum energy. Iron line fluorescence from an opaque, cool shell of material at the Alfven surface provides the necessary luminosity in this feature. The line energy width can be due to Doppler broadening if the shell is forced to corotate with the pulsar at a radius 800 million cm. Implications of this model regarding physical conditions near Her X-1 are discussed.

  10. Experimental demonstration of direct L-shell x-ray fluorescence imaging of gold nanoparticles using a benchtop x-ray source

    SciTech Connect

    Manohar, Nivedh; Reynoso, Francisco J.; Cho, Sang Hyun [Nuclear/Radiological Engineering and Medical Physics Programs, Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0405 (United States)] [Nuclear/Radiological Engineering and Medical Physics Programs, Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0405 (United States)

    2013-08-15

    Purpose: To develop a proof-of-principle L-shell x-ray fluorescence (XRF) imaging system that locates and quantifies sparse concentrations of gold nanoparticles (GNPs) using a benchtop polychromatic x-ray source and a silicon (Si)-PIN diode x-ray detector system.Methods: 12-mm-diameter water-filled cylindrical tubes with GNP concentrations of 20, 10, 5, 0.5, 0.05, 0.005, and 0 mg/cm{sup 3} served as calibration phantoms. An imaging phantom was created using the same cylindrical tube but filled with tissue-equivalent gel containing structures mimicking a GNP-loaded blood vessel and approximately 1 cm{sup 3} tumor. Phantoms were irradiated by a 3-mm-diameter pencil-beam of 62 kVp x-rays filtered by 1 mm aluminum. Fluorescence/scatter photons from phantoms were detected at 90° with respect to the beam direction using a Si-PIN detector placed behind a 2.5-mm-diameter lead collimator. The imaging phantom was translated horizontally and vertically in 0.3-mm steps to image a 6 mm × 15 mm region of interest (ROI). For each phantom, the net L-shell XRF signal from GNPs was extracted from background, and then corrected for detection efficiency and in-phantom attenuation using a fluorescence-to-scatter normalization algorithm.Results: XRF measurements with calibration phantoms provided a calibration curve showing a linear relationship between corrected XRF signal and GNP mass per imaged voxel. Using the calibration curve, the detection limit (at the 95% confidence level) of the current experimental setup was estimated to be a GNP mass of 0.35 ?g per imaged voxel (1.73 × 10{sup ?2} cm{sup 3}). A 2D XRF map of the ROI was also successfully generated, reasonably matching the known spatial distribution as well as showing the local variation of GNP concentrations.Conclusions: L-shell XRF imaging can be a highly sensitive tool that has the capability of simultaneously imaging the spatial distribution and determining the local concentration of GNPs presented on the order of parts-per-million level within subcentimeter-sized ex vivo samples and superficial tumors during preclinical animal studies.

  11. Comparison of Synchrotron X-Ray Fluorescence Mapping and Micro-XANES to Bulk X-Ray Absorption Spectra in Metal-Contaminated Sediments

    SciTech Connect

    O'Day, P; Carroll, S A; Bajt, S

    2003-01-16

    Synchrotron X-ray absorption spectroscopy (XAS) is one of the few techniques that can supply molecular-scale information for a variety of elements at concentrations relevant to natural systems in non-vacuum conditions. Bulk XAS analysis supplies the dominant chemical bonding mode(s) for a specific element. In complex materials such as natural soils and sediments, however, the dominant mode may not necessarily be the most reactive because changes in speciation at surfaces may results in changes in reactivity. Our previous work at Naval Air Station (NAS) Alameda (CA) focused on in situ metal chemistry in surface and deep sediments, and the impact of metal mobility by sediment oxidation. Estuary sediments at the Alameda Naval Station Air in California have elevated metal concentrations that increase with increasing depth. The metal concentrations in these sediments are: Cd (10-350 ppm), Cr (200-1000 ppm), Cu (100-230 ppm), Pb (200-1200 ppm) and Zn (250-600 ppm). We have extensively characterized these sediments using bulk XAS and other non-synchrotron supporting methods [ 1]. In this experiment, we collected fluorescence element maps using synchrotron X-ray microprobe of unreacted and seawater-oxidized sediment samples from Alameda NAS to determine the spatial distribution and correlation of lead, zinc, and iron. We then compared micro-XANES spectra for lead and zinc collected with the X-ray microprobe to previously collected bulk XANES spectra. The results from our bulk XAS characterization of the sediments showed both oxide and sulfide components for the trace metals. However, the bulk XAS data were not able to identify the composition of the oxide component (i.e. carbonate or hydroxide), nor could absorbed species or solid solutions be definitively identified. Our objective in using micro-XANES and fluorescence element maps was to attempt a more precise identification of metal speciation in or on individual particles.

  12. [Determination of major elements in superphosphate by X-ray fluorescence spectrometry].

    PubMed

    Rui, Yu-Kui; Li, He; Shen, Jian-Bo; Zhang, Fu-Suo

    2008-11-01

    Phosphate fertilizer is one of the most important fertilizers. The authors determined nine kinds of major elements in superphosphate, the most important phosphate fertilizer, by X-ray fluorescence spectrometry. The detection range of SiO2, Al2O3, TFe2O3, MnO, MgO, CaO, Na2O, K2O and P2O5 is 15.0%-90.0%, 0.20%-25.0%, 0.20%-25.0%, 0.01%-0.35%, 0.20%-40.0%, 0.10%-35.0%, 0.10%-7.50%, 0.05%-7.50% and 1.00%-100.00% respectively, and the precision of the method for SiO2, Al2O3, TFe2O3, MnO, MgO, CaO, Na2O, K2O and P2O5 range from 0.20% to 0.005%, so the method of X-ray fluorescence spectrometry is a fast and effectual method for detecting the composition of phosphate fertilizer. The contents of the above elements showed (1) the detected superphosphate content is 18.101% of P2O5, which is accordant to the labeled level (> or = 16%); (2) the detected superphosphate contains much SiO2, TFe2O3, MgO, CaO and K2O, which are necessary for plant growth and the content of which is 16.954%, 1.495%, 1.580%, 21.428% and 1.585% respectively. These data showed that phosphate fertilizer sometimes can supply some trace elements for plants, but we should eliminate the interference effect of these elements when we research the role of phosphorus; (3) superphosphate contains 3.225% of Al2O3, so the authors should attention to the aluminium poison when superphosphate is used chronically. PMID:19271522

  13. High resolution X-ray fluorescence imaging for a microbeam radiation therapy treatment planning system

    NASA Astrophysics Data System (ADS)

    Chtcheprov, Pavel; Inscoe, Christina; Burk, Laurel; Ger, Rachel; Yuan, Hong; Lu, Jianping; Chang, Sha; Zhou, Otto

    2014-03-01

    Microbeam radiation therapy (MRT) uses an array of high-dose, narrow (~100 ?m) beams separated by a fraction of a millimeter to treat various radio-resistant, deep-seated tumors. MRT has been shown to spare normal tissue up to 1000 Gy of entrance dose while still being highly tumoricidal. Current methods of tumor localization for our MRT treatments require MRI and X-ray imaging with subject motion and image registration that contribute to the measurement error. The purpose of this study is to develop a novel form of imaging to quickly and accurately assist in high resolution target positioning for MRT treatments using X-ray fluorescence (XRF). The key to this method is using the microbeam to both treat and image. High Z contrast media is injected into the phantom or blood pool of the subject prior to imaging. Using a collimated spectrum analyzer, the region of interest is scanned through the MRT beam and the fluorescence signal is recorded for each slice. The signal can be processed to show vascular differences in the tissue and isolate tumor regions. Using the radiation therapy source as the imaging source, repositioning and registration errors are eliminated. A phantom study showed that a spatial resolution of a fraction of microbeam width can be achieved by precision translation of the mouse stage. Preliminary results from an animal study showed accurate iodine profusion, confirmed by CT. The proposed image guidance method, using XRF to locate and ablate tumors, can be used as a fast and accurate MRT treatment planning system.

  14. Atomic Calculations and Laboratory Measurements Relevant to X-ray Warm Absorbers

    NASA Technical Reports Server (NTRS)

    Kallman, Tim; Bautista, M.; Palmeri, P.

    2007-01-01

    This viewgraph document reviews the atomic calculations and the measurements from the laboratory that are relevant to our understanding of X-Ray Warm Absorbers. Included is a brief discussion of the theoretical and the experimental tools. Also included is a discussion of the challenges, and calculations relevant to dielectronic recombination, photoionization cross sections, and collisional ionization. A review of the models is included, and the sequence that the models were applied.

  15. X-ray fluorescence imaging reveals subcellular biometal disturbances in a childhood neurodegenerative disorder.

    PubMed

    Grubman, A; James, S A; James, J; Duncan, C; Volitakis, I; Hickey, J L; Crouch, P J; Donnelly, P S; Kanninen, K M; Liddell, J R; Cotman, S L; de Jonge; White, A R

    2014-06-01

    Biometals such as zinc, iron, copper and calcium play key roles in diverse physiological processes in the brain, but can be toxic in excess. A hallmark of neurodegeneration is a failure of homeostatic mechanisms controlling the concentration and distribution of these elements, resulting in overload, deficiency or mislocalization. A major roadblock to understanding the impact of altered biometal homeostasis in neurodegenerative disease is the lack of rapid, specific and sensitive techniques capable of providing quantitative subcellular information on biometal homeostasis in situ. Recent advances in X-ray fluorescence detectors have provided an opportunity to rapidly measure biometal content at subcellular resolution in cell populations using X-ray Fluorescence Microscopy (XFM). We applied this approach to investigate subcellular biometal homeostasis in a cerebellar cell line isolated from a natural mouse model of a childhood neurodegenerative disorder, the CLN6 form of neuronal ceroid lipofuscinosis, commonly known as Batten disease. Despite no global changes to whole cell concentrations of zinc or calcium, XFM revealed significant subcellular mislocalization of these important biological second messengers in cerebellar Cln6(nclf) (CbCln6(nclf) ) cells. XFM revealed that nuclear-to-cytoplasmic trafficking of zinc was severely perturbed in diseased cells and the subcellular distribution of calcium was drastically altered in CbCln6(nclf) cells. Subtle differences in the zinc K-edge X-ray Absorption Near Edge Structure (XANES) spectra of control and CbCln6(nclf) cells suggested that impaired zinc homeostasis may be associated with an altered ligand set in CbCln6(nclf) cells. Importantly, a zinc-complex, Zn(II)(atsm), restored the nuclear-to-cytoplasmic zinc ratios in CbCln6(nclf) cells via nuclear zinc delivery, and restored the relationship between subcellular zinc and calcium levels to that observed in healthy control cells. Zn(II)(atsm) treatment also resulted in a reduction in the number of calcium-rich puncta observed in CbCln6(nclf) cells. This study highlights the complementarities of bulk and single cell analysis of metal content for understanding disease states. We demonstrate the utility and broad applicability of XFM for subcellular analysis of perturbed biometal metabolism and mechanism of action studies for novel therapeutics to target neurodegeneration. PMID:24976945

  16. X-ray fluorescence imaging reveals subcellular biometal disturbances in a childhood neurodegenerative disorder

    PubMed Central

    Grubman, A.; James, S.A; James, J.; Duncan, C.; Volitakis, I.; Hickey, J.L.; Crouch, P.J.; Donnelly, P.S.; Kanninen, K.M.; Liddell, J.R.; Cotman, S.L.; de Jonge; White, A.R.

    2014-01-01

    Biometals such as zinc, iron, copper and calcium play key roles in diverse physiological processes in the brain, but can be toxic in excess. A hallmark of neurodegeneration is a failure of homeostatic mechanisms controlling the concentration and distribution of these elements, resulting in overload, deficiency or mislocalization. A major roadblock to understanding the impact of altered biometal homeostasis in neurodegenerative disease is the lack of rapid, specific and sensitive techniques capable of providing quantitative subcellular information on biometal homeostasis in situ. Recent advances in X-ray fluorescence detectors have provided an opportunity to rapidly measure biometal content at subcellular resolution in cell populations using X-ray Fluorescence Microscopy (XFM). We applied this approach to investigate subcellular biometal homeostasis in a cerebellar cell line isolated from a natural mouse model of a childhood neurodegenerative disorder, the CLN6 form of neuronal ceroid lipofuscinosis, commonly known as Batten disease. Despite no global changes to whole cell concentrations of zinc or calcium, XFM revealed significant subcellular mislocalization of these important biological second messengers in cerebellar Cln6nclf (CbCln6nclf) cells. XFM revealed that nuclear-to-cytoplasmic trafficking of zinc was severely perturbed in diseased cells and the subcellular distribution of calcium was drastically altered in CbCln6nclf cells. Subtle differences in the zinc K-edge X-ray Absorption Near Edge Structure (XANES) spectra of control and CbCln6nclf cells suggested that impaired zinc homeostasis may be associated with an altered ligand set in CbCln6nclf cells. Importantly, a zinc-complex, ZnII(atsm), restored the nuclear-to-cytoplasmic zinc ratios in CbCln6nclf cells via nuclear zinc delivery, and restored the relationship between subcellular zinc and calcium levels to that observed in healthy control cells. ZnII(atsm) treatment also resulted in a reduction in the number of calcium-rich puncta observed in CbCln6nclf cells. This study highlights the complementarities of bulk and single cell analysis of metal content for understanding disease states. We demonstrate the utility and broad applicability of XFM for subcellular analysis of perturbed biometal metabolism and mechanism of action studies for novel therapeutics to target neurodegeneration. PMID:24976945

  17. X-ray nanoprobes and diffraction-limited storage rings: opportunities and challenges of fluorescence tomography of biological specimens

    PubMed Central

    de Jonge, Martin D.; Ryan, Christopher G.; Jacobsen, Chris J.

    2014-01-01

    X-ray nanoprobes require coherent illumination to achieve optic-limited resolution, and so will benefit directly from diffraction-limited storage rings. Here, the example of high-resolution X-ray fluorescence tomography is focused on as one of the most voracious demanders of coherent photons, since the detected signal is only a small fraction of the incident flux. Alternative schemes are considered for beam delivery, sample scanning and detectors. One must consider as well the steps before and after the X-ray experiment: sample preparation and examination conditions, and analysis complexity due to minimum dose requirements and self-absorption. By understanding the requirements and opportunities for nanoscale fluorescence tomography, one gains insight into the R&D challenges in optics and instrumentation needed to fully exploit the source advances that diffraction-limited storage rings offer. PMID:25177992

  18. X-Ray Fluorescence Spectrometry of Lunar Surface by XRS Onboard SELENE (Kaguya)

    NASA Astrophysics Data System (ADS)

    Okada, Tatsuaki; Shirai, Kei; Yamamoto, Yukio; Arai, Takehiko; Ogawa, Kazunori; Shiraishi, Hiroaki; Iwasaki, Masatsuna; Kawamura, Taichi; Morito, Hisataka; Grande, Manuel; Kato, Manabu

    The status of the X-ray spectrometer XRS onboard SELENE (Kaguya) is reported. The XRS is to map major elemental composition of lunar surface but is subject to instrumental trouble and unexpectedly faint solar activity. However it observed X-rays from the onboard standard sample excited by solar X-rays and non-solar X-ray events, maybe by particle events.

  19. A New In Situ Method of Determining Relative Abundances and Charge States of Implanted Transition Metals in Individual Grains Using Synchrotron X-Ray Fluorescence

    SciTech Connect

    Kitts, K.; Sutton, S.; Newville, M. (NIU); (UofC)

    2007-03-06

    We report on a new in situ method of determining relative abundances and charge states of implanted transition metals in individual grains using synchrotron X-ray fluorescence. In order to determine in situ the relative abundances and charge states of the transition metals in implanted solar wind in individual lunar plagioclase grains, we have developed a new microbeam x-ray fluorescence method using the synchrotron x-ray microprobe at the Advanced Photon Source (GSECARS sector 13) at Argonne National Laboratory.

  20. Determination of iron in nuclear grade zirconium oxide by x-ray fluorescence spectrometry using an internal intensity reference

    Microsoft Academic Search

    G. Radha Krishna; H. R. Ravindra; B. Gopalan; S. Syamsunder

    1995-01-01

    Iron forms an important constituent of zirconium alloys that are specially chosen for the fabrication of nuclear reactor core components. The concentration of iron in intermediate products is closely monitored during the manufacture of these alloys starting from the chemical processing of the ore zircon. In order to accomplish this, an x-ray fluorescence spectrometric technique using an internal ratio method

  1. An electrochemical enrichment procedure for the determination of heavy metals by total-reflection X-ray fluorescence spectroscopy

    Microsoft Academic Search

    A. Ritschel; P Wobrauschek; E Chinea; F Grass; Ch Fabjan

    1999-01-01

    An electrolytic separation and enrichment technique was developed for the determination of trace elements by total-reflection X-ray fluorescence spectroscopy (TXRF). The elements of interest are electrodeposited out of the sample solution onto a solid, polished disc of pure niobium which is used as sample carrier for the TXRF measurement. The electrochemical deposition leads to a high enrichment of the analytes

  2. Determination of Gd and Sm contents in metallofullerenes on a total reflection X-ray fluorescence spectrometer with parallel beam

    NASA Astrophysics Data System (ADS)

    Tikhonova, A. E.; Kozlov, V. S.

    2014-01-01

    The contents of Gd and Sm have been determined quantitatively using the X-ray fluorescence analysis on a total reflection spectrometer with a parallel beam. It has been shown that the results can be used in developments of the technique for measuring the content of Gd metallofullerenes in powder samples several milligrams in weight and in liquid samples several microliters in volume.

  3. An X-Ray Fluorescence Spectrometer (XRF-J) Instrument for Geochemical Element Mapping of the Galilean Satellites

    NASA Astrophysics Data System (ADS)

    Galuba, G. G.; Köhler, E.; Fabel, O.; Meyer, M.; Denk, T.; Schmedemann, N.; van Gasselt, S.

    2012-10-01

    In 2012 JUpiter Icy moons Explorer was chosen to be the next large science mission of the European Space Agency. We propose an X-ray fluorescence instrument package (XRF-J) to investigate the composition of non-icy surface materials on jovian moons.

  4. Total reflection X-ray fluorescence spectrometry for the introduction of novel materials in clean-room production environments

    Microsoft Academic Search

    David Hellin; Stefan De Gendt; Jens Rip; Chris Vinckier

    2005-01-01

    In this paper, a number of case studies on the analysis of novel metallic contaminants on conventional and alternative substrates using the technique of total reflection X-ray fluorescence spectrometry (TXRF) is presented. Investigated materials include Si and Ge substrates, high-? dielectric contaminants, and layers, and Si wafers contaminated with elements from metal gates and Cu interconnects. One focus is on

  5. 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...

  6. Analysis of pigments and inks on oil paintings and historical manuscripts using total reflection x?ray fluorescence spectrometry

    Microsoft Academic Search

    R. Klockenkämper; A. von Bohlen; L. Moens

    2000-01-01

    Old oil paintings and illuminated historical manuscripts are valuable objects of cultural heritage. Pigments and inks once used for these artefacts today allow insights of art historical or archaeological relevance. For their identification, a number of non-destructive spectroanalytical methods can be applied. This paper first gives a historical review and describes fundamentals of optical and x-ray fluorescence spectrometry including instrumentation

  7. FIELD MEASUREMENT TECHNOLOGY FOR MERCURY IN SOIL AND SEDIMENT NITON'S XLI/XLT 700 SERIES X-RAY FLUORESCENCE ANALYZER

    EPA Science Inventory

    NITON's XL-700 Series X-ray fluorescence analyzers were demonstrated under the U.S. Environmental Protection Agency Superfund Innovative Technology Evaluation Program in May 2003 at the Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. The purpose of the Demonstration...

  8. COMPARISON OF LEAD CONCENTRATION IN SURFACE SOIL BY INDUCTED COUPLED PLASMA/OPTICAL EMISSION SPECTROMETRY AND X-RAY FLUORESCENCE

    E-print Network

    Boyer, Edmond

    COMPARISON OF LEAD CONCENTRATION IN SURFACE SOIL BY INDUCTED COUPLED PLASMA/OPTICAL EMISSION by Inducted Coupled Plasma/Optical Emission Spectrometry (ICP/OES) and by X-ray fluorescence (XRF). During of composite soil samples and analyses at laboratory by the Inducted Coupled Plasma/Optical Emission

  9. Screening heavy metals levels in hair of sanitation workers by X-ray fluorescence Jauharah Md Khudzari b,1

    E-print Network

    Short, Daniel

    Screening heavy metals levels in hair of sanitation workers by X-ray fluorescence analysis Jauharah online 28 July 2012 Keywords: Hair Heavy metal EDXRF As Hg Pb a b s t r a c t This work presents a study of human hair as a bio-indicator for detection of heavy metals as part of environmental health surveillance

  10. Evaluation of an in-situ x-ray fluorescence analyzer for inorganic pollutants in sediments and water columns

    Microsoft Academic Search

    Wogman

    1979-01-01

    The applicability of an energy dispersive x-ray fluorescence spectrometer for measurement of trace elements in sediments and in water columns from Coast Guard vessels has been investigated. This investigation was conducted in both freshwater and saltwater areas and included Puget Sound, Lake Washington, Lake Union, and the ship canal in the State of Washington. The spectrometer system consisted of a

  11. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - FIELD PORTABLE X-RAY FLUORESCENCE ANALYZER - METOREX, INC. X-MET 920-P AND 940

    EPA Science Inventory

    In April 1995, the U.S. Environmental Protection Agency (EPA) sponsored a demonstration of field portable X-ray fluorescence (FPXRF) analyzers. The primary objectives of this demonstration were (1) to determine how well FPXRF analyzers perform in comparison to standard reference...

  12. Study of heavy metals in wild edible mushrooms under different pollution conditions by X-ray fluorescence spectrometry.

    PubMed

    Carvalho, M L; Pimentel, A C; Fernandes, B

    2005-07-01

    In this work we studied and compared the metal uptake in edible mushrooms (Lepiota procera, Boletus badius, Boletus edulis, Tricholoma equestry, Lactarius deliciosus, Cantarelus tubalformis and Cantarelus edulis), relative to sampling sites submitted to different pollution conditions: car traffic, soil pollution due to pesticides and fertilizers used in old vineyards, and incineration of hospital waste. Soil was also collected in some places, and its content was correlated to the corresponding one in some mushrooms species. All samples, without any chemical treatment, were analyzed by an X-ray fluorescence set-up. This technique is based on a monochromatic X-ray beam ionizing the atoms of the sample. Following this ionization, the emitted radiation is characteristic of the element, allowing its identification and quantification. Vineyards are normally submitted to very high amounts of sulfating, containing high copper concentrations. This metal is accumulated on the soil, and can be up-taken by vegetation. Very high levels of Fe and Cu were found in Lepiota procera species in old vineyards. Zinc was found to be always higher than Cu by factors ranging from 1.5 to 8 in clean wood taken as a reference for the whole analyzed species, while in old vineyards the ratio Zn/Cu reach 0.25 for Lepiota procera. This is correlated to the soil content for both elements. In addition, pollution induced by car traffic was checked in some samples, collected in the proximity of highways. Pb was the main contaminant in these areas, and presenting values 10 times higher than the corresponding ones in sites not submitted to pollution, for some species. Mushrooms contamination due to incineration of hospital waste was also studied, but we did not observe any contamination involving heavy metals in the several analyzed species around these areas. This is in agreement with what was expected, taking into account that hospital waste is mostly organic and, in principle, no heavy metals would be observed. PMID:16038488

  13. Development of Standard Samples for on-board Calibration of a New Planetary X-Ray Fluorescence Spectrometer

    NASA Astrophysics Data System (ADS)

    Dreißigacker, Anne; Köhler, Eberhard; Fabel, Oliver; van Gasselt, Stephan

    2014-05-01

    At the Planetary Sciences and Remote Sensing research group at Freie Universität Berlin an SCD-based X-Ray Fluorescence Spectrometer is being developed to be employed on planetary orbiters to conduct direct, passive energy-dispersive x-ray fluorescence measurements of planetary surfaces through measuring the emitted X-Ray fluorescence induced by solar x-rays and high energy particles. Because the Sun is a highly variable radiation source, the intensity of solar X-Ray radiation has to be monitored constantly to allow for comparison and signal calibration of X-Ray radiation from lunar surface materials. Measurements are obtained by indirectly monitoring incident solar x-rays emitted from a calibration sample. This has the additional advantage of minimizing the risk of detector overload and damage during extreme solar events such as high-energy solar flares and particle storms as only the sample targets receive the higher radiation load directly (while the monitor is never directly pointing towards the Sun). Quantitative data are being obtained and can be subsequently analysed through synchronous measurement of fluorescence of the Moon's surface by the XRF-S main instrument and the emitted x-ray fluorescence of calibration samples by the XRF-S-ISM (Indirect Solar Monitor). We are currently developing requirements for 3 sample tiles for onboard correction and calibration of XRF-S, each with an area of 3-9 cm2 and a maximum weight of 45 g. This includes development of design concepts, determination of techniques for sample manufacturing, manufacturing and testing of prototypes and statistical analysis of measurement characteristics and quantification of error sources for the advanced prototypes and final samples. Apart from using natural rock samples as calibration sample, we are currently investigating techniques for sample manufacturing including laser sintering of rock-glass on metals, SiO2-stabilized mineral-powders, or artificial volcanic glass. High precision measurements of the chemical composition of the final samples (EPMA, various energy-dispersive XRF) will serve as calibration standard for XRF-S. Development is funded by the German Aerospace Agency under grant 50 JR 1303.

  14. State analysis of sulfur in coal and coal fly ash by double-crystal X-ray fluorescence spectrometry

    Microsoft Academic Search

    K. Furuya; Y. Kato; T. Kikuchi; Y. Gohshi

    1983-01-01

    Summary Double-crystal high-resolution X-ray fluorescence spectrometry was applied to the state analysis of sulfur in coal and related fly ash. For total sulfur, a proportional relationship exists between fluorescence intensities and the analytical values obtained by the oxygen-combustion method. Two oxidation states of sulfur were identified by a least square curve fitting method, by assuming that the spectrum profile is

  15. Ultraviolet Germicidal Irradiation and Its Effects on Elemental Distributions in Mouse Embryonic Fibroblast Cells in X-Ray Fluorescence Microanalysis

    PubMed Central

    Jin, Qiaoling; Vogt, Stefan; Lai, Barry; Chen, Si; Finney, Lydia; Gleber, Sophie-Charlotte; Ward, Jesse; Deng, Junjing; Mak, Rachel; Moonier, Nena; Jacobsen, Chris

    2015-01-01

    Rapidly-frozen hydrated (cryopreserved) specimens combined with cryo-scanning x-ray fluorescence microscopy provide an ideal approach for investigating elemental distributions in biological cells and tissues. However, because cryopreservation does not deactivate potentially infectious agents associated with Risk Group 2 biological materials, one must be concerned with contamination of expensive and complicated cryogenic x-ray microscopes when working with such materials. We employed ultraviolet germicidal irradiation to decontaminate previously cryopreserved cells under liquid nitrogen, and then investigated its effects on elemental distributions under both frozen hydrated and freeze dried states with x-ray fluorescence microscopy. We show that the contents and distributions of most biologically important elements remain nearly unchanged when compared with non-ultraviolet-irradiated counterparts, even after multiple cycles of ultraviolet germicidal irradiation and cryogenic x-ray imaging. This provides a potential pathway for rendering Risk Group 2 biological materials safe for handling in multiuser cryogenic x-ray microscopes without affecting the fidelity of the results. PMID:25706293

  16. Electron density and effective atomic number (Zeff) determination through x-ray Moiré deflectometry

    NASA Astrophysics Data System (ADS)

    Valdivia Leiva, Maria Pia; Stutman, Dan; Finkenthal, Michael

    2014-10-01

    Talbot-Lau based Moiré deflectometry is a powerful density diagnostic capable of delivering refraction information and attenuation from a single image, through the accurate detection of X-ray phase-shift and intensity. The technique is able to accurately measure both the real part of the index of refraction ? (directly related to electron density) and the attenuation coefficient ? of an object placed in the x-ray beam. Since the atomic number Z (or Zeff for a composite sample) is proportional to these quantities, an elemental map of the effective atomic number can be obtained with the ratio of the phase and the absorption image. The determination of Zeff from refraction and attenuation measurements with Moiré deflectometry could be of high interest in various fields of HED research such as shocked materials and ICF experiments as Zeff is linked, by definition, to the x-ray absorption properties of a specific material. This work is supported by U.S. DoE/NNSA Grant No. 435 DENA0001835.

  17. Improved micro x-ray fluorescence spectrometer for light element analysis

    NASA Astrophysics Data System (ADS)

    Smolek, Stephan; Streli, Christina; Zoeger, Norbert; Wobrauschek, Peter

    2010-05-01

    Since most available micro x-ray fluorescence (micro-XRF) spectrometers operate in air, which does not allow the analysis of low-Z elements (Z?14), a special micro-XRF spectrometer has been designed to extend the analytical range down to light elements (Z?6). It offers improved excitation and detection conditions necessary for light element analysis. To eliminate absorption of the exciting and fluorescent radiation, the system operates under vacuum condition. Sample mapping is automated and controlled by specialized computer software developed for this spectrometer. Several different samples were measured to test and characterize the spectrometer. The spot size has been determined by scans across a 10 ?m Cu wire which resulted in a full width at half maximum of 31 ?m for Mo K? line (17.44 keV) and 44 ?m effective beam size for the Cu K edge and 71 ?m effective beam size for the Cu L edge. Lower limits of detection in the picogram range for each spot (or ?g/cm2) were obtained by measuring various thin metal foils under different conditions. Furthermore, detection limits in the parts per million range were found measuring NIST621 standard reference material. Area scans of a microscopic laser print and NaF droplet were performed to show mapping capabilities.

  18. Breakthrough: X-ray Laser Captures Atoms and Molecules in Action

    SciTech Connect

    Bergmann, Uwe

    2012-04-26

    The Linac Coherent Light Source at SLAC is the world's most powerful X-ray laser. Just two years after turning on in 2009, breakthrough science is emerging from the LCLS at a rapid pace. A recent experiment used the X-rays to create and probe a 2-million-degree piece of matter in a controlled way for the first time-a significant leap toward understanding the extreme conditions found in the hearts of stars and giant planets, and a finding which could further guide research into nuclear fusion, the mechanism that powers the sun. Upcoming experiments will investigate the fundamental, atomic-scale processes behind such phenomena as superconductivity and magnetism, as well as peering into the molecular workings of photosynthesis in plants.

  19. X-Ray Microprobe of Orbital Alignment in Strong-Field Ionized Atoms

    SciTech Connect

    Young, L.; Arms, D. A.; Dufresne, E. M.; Dunford, R. W.; Ederer, D. L.; Hoehr, C.; Kanter, E. P.; Kraessig, B.; Landahl, E. C.; Peterson, E. R.; Rudati, J.; Santra, R.; Southworth, S. H. [Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2006-08-25

    We have developed a synchrotron-based, time-resolved x-ray microprobe to investigate optical strong-field processes at intermediate intensities (10{sup 14}-10{sup 15} W/cm{sup 2}). This quantum-state specific probe has enabled the direct observation of orbital alignment in the residual ion produced by strong-field ionization of krypton atoms via resonant, polarized x-ray absorption. We found strong alignment to persist for a period long compared to the spin-orbit coupling time scale (6.2 fs). The observed degree of alignment can be explained by models that incorporate spin-orbit coupling. The methodology is applicable to a wide range of problems.

  20. Distribution and speciation of bromine in mammalian tissue and fluids by X-ray fluorescence imaging and X-ray absorption spectroscopy.

    PubMed

    Ceko, Melanie J; Hummitzsch, Katja; Hatzirodos, Nicholas; Bonner, Wendy; James, Simon A; Kirby, Jason K; Rodgers, Raymond J; Harris, Hugh H

    2015-05-13

    Bromine is one of the most abundant and ubiquitous trace elements in the biosphere and until recently had not been shown to perform any essential biological function in animals. A recent study demonstrated that bromine is required as a cofactor for peroxidasin-catalysed formation of sulfilimine crosslinks in Drosophila. In addition, bromine dietary deficiency is lethal in Drosophila, whereas bromine replenishment restores viability. The aim of this study was to examine the distribution and speciation of bromine in mammalian tissues and fluids to provide further insights into the role and function of this element in biological systems. In this study we used X-ray fluorescence (XRF) imaging and inductively coupled plasma-mass spectrometry (ICP-MS) to examine the distribution of bromine in bovine ovarian tissue samples, follicular fluid and aortic serum, as well as human whole blood and serum and X-ray absorption spectroscopy (XAS) to identify the chemical species of bromine in a range of mammalian tissue (bovine, ovine, porcine and murine), whole blood and serum samples (bovine, ovine, porcine, murine and human), and marine samples (salmon (Salmo salar), kingfish (Seriola lalandi) and Scleractinian coral). Bromine was found to be widely distributed across all tissues and fluids examined. In the bovine ovary in particular it was more concentrated in the sub-endothelial regions of arterioles. Statistical comparison of the near-edge region of the X-ray absorption spectra with a library of bromine standards led to the conclusion that the major form of bromine in all samples analysed was bromide. PMID:25675086

  1. Novel handheld x-ray fluorescence spectrometer for routine testing for the presence of lead

    NASA Astrophysics Data System (ADS)

    Rensing, Noa M.; Tiernan, Timothy C.; Squillante, Michael R.

    2011-06-01

    RMD is developing a safe, inexpensive, and easy to operate lead detector for retailers and consumers that can reliably detect dangerous levels of lead in toys and other household products. Lead and its compounds have been rated as top chemicals that pose a great threat to human health. However, widespread testing for environmental lead is rarely undertaken until lead poisoning has already been diagnosed. The problem is not due to the accuracy or sensitivity of existing lead detection technology, but rather to the high expense, safety and licensing barriers of available test equipment. An inexpensive and easy to use lead detector would enable the identification of highly contaminated objects and areas and allow for timely and cost effective remediation. The military has similar needs for testing for lead and other heavy elements such as mercury, primarily in the decontamination of former military properties prior to their return to civilian use. RMD's research and development efforts are abased on advanced solid-state detectors combined with recently patented lead detection techniques to develop a consumer oriented lead detector that will be widely available and easy and inexpensive to use. These efforts will result in an instrument that offers: (1) high sensitivity, to identify objects containing dangerous amounts of lead, (2) low cost to encourage widespread testing by consumers and other end users and (3) convenient operation requiring no training or licensing. In contrast, current handheld x-ray fluorescence spectrometers either use a radioactive source requiring licensing and operating training, or use an electronic x-ray source that limits their sensitivity to surface lead.

  2. Hard X-ray Fluorescence Measurements of Heteroepitaxial Solid Oxide Fuel Cell Cathode Materials

    SciTech Connect

    Davis, Jacob N.; Miara, Lincoln J.; Saraf, Laxmikant V.; Kaspar, Tiffany C.; Gopalan, Srikanth; Pal, Uday B.; Woicik, Joseph C.; Basu, Soumendra N.; Ludwig, Karl F.

    2012-12-01

    Commonly, SOFCs are operated at high temperatures (above 800°C). At these temperatures expensive housing is needed to contain an operating stack as well as coatings to contain the oxidation of the metallic interconnects. Lowering the temperature of an operating device would allow for more conventional materials to be used, thus lowering overall cost. Understanding the surface chemical states of cations in the surface of the SOFC cathode is vital to designing a system that will perform well at lower temperatures. The samples studied were grown by pulsed laser deposition (PLD) at the Environmental Molecular Sciences Laboratory (EMSL) at Pacific Northwest National Laboratory (PNNL). 20% strontium doped lanthanum manganite (LSM-20) was grown on YSZ and NGO (neodymium gallate). The films on YSZ have a fiber texture. LSM-20 on NGO is heteroepitaxial. Lanthanum strontium cobalt ferrite (LSCF-6428) films were grown on LAO and YSZ with a GDC barrier layer. Total X-ray Reflection Fluorescence (TXRF) was used to depth profile the samples. In a typical experiment, the angle of the incident beam is varied though the critical angle. Below the critical angle, the x-ray decays as an evanescent wave and will only penetrate the top few nanometers. TXRF experiments done on LSM films have suggested strontium segregates to the surface and form strontium enriched nanoparticles (1). It should be pointed out that past studies have focused on 30% strontium A-site doping, but this project uses 20% strontium doped lanthanum manganite. XANES and EXAFS data were taken as a function of incoming angle to probe composition as a function of depth. XANES spectra can be difficult to analyze fully. For other materials density functional theory calculations compared to near edge measurements have been a good way to understand the 3d valence electrons (2).

  3. Compton scattering of an X-ray photon by an open-shell atom

    SciTech Connect

    Hopersky, A. N., E-mail: hopersky_vm_1@rgups.ru; Nadolinsky, A. M. [Rostov State University of Transport Communication (Russian Federation)

    2012-09-15

    A nonrelativistic quantum theory for the nonresonant Compton scattering of an X-ray photon by a free many-electron atom with an open shell in the ground state has been constructed in the single-configuration Hartree-Fock approximation outside the impulse approximation widely used in the literature. The transition to an atom with closed shells reproduces the results obtained previously in [6, 7]. The results of a test calculation for atoms with open (Ti, Fe) and closed (Zn) 3d core shells are presented. The effects of the radial relaxation of one-electron states in the field of core vacancies have been taken into account. The results of the calculation agree well with the experimental results [15, 16]. It has been established that the results of the impulse approximation in the investigated X-ray photon energy ranges disagree with those of our theory not only quantitatively but also qualitatively. In particular, the impulse approximation near the elastic (Thomson and Rayleigh) scattering line leads to a gross overestimation of the contributions from the deep atomic shells involved in the inelastic photon scattering only virtually to the scattering probability. The presented theory is general in character and its applicability to a particular element of the Mendeleev table with an open core shell or to a many-electron atomic ion is limited only by the requirement that the nonrelativistic Hartree-Fock approximation be properly used in describing the scattering-state wave functions.

  4. 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.

  5. Mineralogical analysis of clays in hardsetting soil horizons, by X-ray fluorescence and X-ray diffraction using Rietveld method

    NASA Astrophysics Data System (ADS)

    Prandel, L. V.; Saab, S. C.; Brinatti, A. M.; Giarola, N. F. B.; Leite, W. C.; Cassaro, F. A. M.

    2014-02-01

    Diffraction and spectroscopic techniques have been shown to be suitable for obtaining physical and mineralogical properties in polycrystalline soil samples, and also in their precursor compounds. For instance, the X-ray fluorescence (XRF) spectroscopy allows obtaining the elemental composition of an investigated sample, while the X-ray diffraction (XRD) technique permits obtaining qualitative and quantitative composition of the soil minerals through the Rietveld method (RM). In this study Yellow Latosol (Oxisol), Yellow Argisol (Ultisol) and Gray Argisol (Ultisol) soil samples, classified as "hardsetting soils", extracted from areas located at Northeast and Southeast of Brazilian coast were investigated. The soils and their fractions were analyzed in an EDX-700 and an XRD-6000 (Cu K? radiation). XRF results indicate high percentages of Si and Al, and small percentage of Fe and Ti in the investigated samples. The DRX data and RM indicate that there was a predominance of kaolinite and halloysite minerals (kaolin group minerals) in the clay fractions, which are presumably responsible for the formation of kaolinitic plasma in these soils. Also, the obtained results showed that the XRF, XRD techniques and RM were very helpful for investigating the mineralogical composition of a hardsetting soil.

  6. Portable energy dispersive X-ray fluorescence spectrometry and PIXE for elemental quantification of historical paper documents

    NASA Astrophysics Data System (ADS)

    Manso, M.; Reis, M. A.; Candeias, J.; Carvalho, M. L.

    2013-03-01

    We have used a portable energy dispersive X-ray fluorescence spectrometer based on a silicon drift detector for elemental quantification of a historical paper document. Quantitative calculations were carried out using the WinAxil software package. In order to minimize matrix effects and to accurately reflect the conditions under which quantification is usually performed, the fundamental parameters package with a known paper samples was used. Reference values for paper samples were obtained through a set of a particle induced X-ray emission techniques.

  7. Fast automatic segmentation of anatomical structures in x-ray computed tomography images to improve fluorescence molecular tomography reconstruction

    NASA Astrophysics Data System (ADS)

    Freyer, Marcus; Ale, Angelique; Schulz, Ralf B.; Zientkowska, Marta; Ntziachristos, Vasilis; Englmeier, Karl-Hans

    2010-05-01

    The recent development of hybrid imaging scanners that integrate fluorescence molecular tomography (FMT) and x-ray computed tomography (XCT) allows the utilization of x-ray information as image priors for improving optical tomography reconstruction. To fully capitalize on this capacity, we consider a framework for the automatic and fast detection of different anatomic structures in murine XCT images. To accurately differentiate between different structures such as bone, lung, and heart, a combination of image processing steps including thresholding, seed growing, and signal detection are found to offer optimal segmentation performance. The algorithm and its utilization in an inverse FMT scheme that uses priors is demonstrated on mouse images.

  8. Synchrotron x-ray fluorescence microprobe: Quantification and mapping of mixed valence state samples using micro-XANES

    SciTech Connect

    Sutton, S.R. (Department of the Geophysical Sciences and Center for Advanced Radiation Sources, The University of Chicago, Chicago, Illinois 60637 (United States)); Bajt, S. (Department of the Geophysical Sciences and Center for Advanced Radiation Sources, The University of Chicago, Chicago, Illinois 60637 (United States) Department of Applied Science, Brookhaven National Laboratory, Upton, New York 11973 (United States)); Delaney, J. (Department of Geological Sciences, Rutgers University, New Brunswick, New Jersey 08903 (United States)); Schulze, D. (Agronomy Department, Purdue University, W. Lafayette, Indiana 47907 (United States)); Tokunaga, T. (Earth Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States))

    1995-02-01

    The synchrotron x-ray fluorescence microprobe is a valuable instrument for quantification and mapping of mixed valence state samples with high spatial resolution and elemental sensitivity. A method has been developed for quantifying the proportions of Fe[sup 2+] and Fe[sup 3+] with 100 [mu]m spatial resolution and better than 100 ppm sensitivity using x-ray absorption near-edge structure (XANES). Applications of valence state mapping have been made to selenium in water-saturated sediments and manganese associated with wheat roots attacked by the take-all fungus.

  9. X-ray Fluorescence Observations of the Moon by SMART-1/D-CIXS

    NASA Astrophysics Data System (ADS)

    Grande, Manuel; Swinyard, B.; Joy, K. H.; Kellett, Barry J.; Crawford, Ian A.; Howe, Chris J.

    2008-09-01

    Introduction The SMART-1 mission to the Moon included in its payload D-CIXS, a compact X-ray spectrometer [1], [2] SMART-1 was a technology evaluation mission, and D-CIXS was the first of a new generation of planetary X-ray spectrometers. Novel technologies enabled new capabilities for measuring the fluorescent yield of a planetary surface or atmosphere which is illuminated by solar X-rays. During the extended SMART-1 cruise phase, observations of the Earth showed strong argon emission, providing a good source for calibration and demonstrating the potential of the technique. At the Moon, observations showed a first unambiguous remote sensing of calcium in the lunar regolith (Grande et al 2007) (Fig 1). Data obtained were broadly consistent with current understanding of mare and highland composition. Ground truth was provided by the returned Apollo and Luna sample sets. We have extended our observations to comparisons of Lunar near and farside, and by careful analysis enabled new elemental lines to be observed. Observations: In March, 2005, the SMART-1 spacecraft reached its nominal lunar orbit, and we began full commissioning for lunar operations. During the pre-commissioning period in mid-January, 2005, observations of the lunar surface were made which coincided with the occurrence of several major M and X class flares. This opportunity provided an excellent chance to observe spatially localized fluorescence from the lunar surface. X-ray fluorescent elemental lines from the lunar surface are detected by all three facets of D-CIXS while the XSM instrument observes the input solar spectrum. At the end of this interval, a long duration M-class solar flare began at 06:00 UTC on the 15th of January, 2005. The flare lasted for more than 1 hour but only ~30 minutes corresponded to D-CIXS observations. At this time SMART-1 was orbiting over the Moon's near-side eastern limb from about the equator, traveling northwards. As SMART-1 flew north, its altitude was also increasing from around 2100 km at 06:00 to ~3100 km at 06:35. Due to the nature of SMART-1's orbit and thermal dynamics, the spacecraft was performing a mid-orbit slew (rotation), and so D-CIXS's three facets had different surface ground tracks during the observation of interest. However, this variability in footprints was very fortuitous as the instrument FOVs included areas of both mare basalt and highland lithologies, which have different and recognizable elemental signatures. Facet 1 (thin Al-filter, 12º FOV) was oriented throughout the observation toward highland areas to the northeast of Mare Crisium. Facet 3 (Mg-filter, 12º FOV) had a ground track that crossed Mare Crisium. Due to the 12º FOV and the 2100 km altitude, the facet 3 footprint always contains a mixture of mare and highland regions. The footprint of facet 2 (thin Alfilter, 8º FOV) encompassed the regions between the two facets shown and covered a mixture of mare and highland regions but with a smaller signal due to its narrower FOV. Fig. 1 shows the particle background corrected spectra from summed data of the 3 D-CIXS facets for the interval 06:00 UTC to 06:35 UTC. Separate facet spectra have been derived by co-adding data from detectors. Essentially, elemental lines seen in the three different facet spectra represent an averaged geochemical signature from the areas covered by the D-CIXS ground tracks. The spectra shown in figure 5 indicate that lowenergy lines (Mg: 1.25 keV, Al; 1.49 keV and Si: 1.74 keV) are observed in detectors from Facet 1 and 2 (Alfilter). Detectors in Facet 3 are covered by a Magnesium filter which was designed to attenuate the signal from Al and Si X-rays, and so in the Facet 3 spectrum Mg is the only significant low-energy peak detected. Data taken from the Facet 3 spectrum also show a clear Fe peak at around 6.4 keV which is interpreted to be related to fluorescence from Mare Crisium (see below). All three facets clearly show the detection of a Ca emission peak at ~3.69 keV. Although inferences about the distribution of Ca in the lunar crust have been made indirectly f

  10. Resonant scattering of an X-ray photon by a heavy atom

    SciTech Connect

    Hopersky, A. N., E-mail: hopersky_vm_1@rgups.ru; Nadolinsky, A. M. [Rostov State University of Transport Communication (Russian Federation)

    2007-10-15

    The influence of many-body and relativistic effects on the absolute values and shape of the double differential cross section for the resonant scattering of a linearly polarized X-ray photon by a free xenon atom near the K-shell ionization threshold has been theoretically analyzed. The evolution of the spatially extended structure of the scattering cross section to the K{sub {alpha}}{sub ,{beta}} structure of the X-ray spectrum of the xenon atom emission has been demonstrated. The calculations have been performed in the dipole approximation for the anomalous dispersion component of the total inelastic scattering amplitude and in the impulse approximation for the contact component of this amplitude. The contribution of the Rayleigh (elastic) scattering component is taken into account using the methods developed in Hopersky et al., J. Phys. B 30, 5131 (1997). The effects of the radial relaxation of the electron shells, spin-orbit splitting, double excitation/ionization of the atomic ground state, as well as the Auger and radiative decays of the produced main vacancies, are considered. Using the results obtained by Tulkki, Phys. Rev. A 32, 3153 (1985) and Biggs et al., At. Data Nucl. Data Tables 16, 201 (1975), the nonrelativistic Hartree-Fock wavefunctions are changed to the relativistic Dirac-Hartree-Fock wavefunctions of the single-particle scattering states when constructing the process probability amplitude. The calculations are predicting and are in good agreement with the synchrotron experiment on the measurement of the absolute values and shape of the double differential cross section for the resonant scattering of an X-ray photon by a free xenon atom reported by Czerwinski et al., Z. Phys. A 322, 183 (1985)

  11. Fingerprint methods for suspended sediment transport processes by using X-ray fluorescence analysis

    NASA Astrophysics Data System (ADS)

    Nakayama, K.; Beitia, C.; Ohtsu, N.; Yamasaki, S.; Yasuyuki, M.; Yamane, M.

    2014-12-01

    Suspended sediment (SS) can have significant impacts on ecological system, and high SS concentration can have significant impacts on human life. In the previous studies, radionuclide analysis has been applied to evaluate the production of SS in the river basins, which demonstrated that the surface soil erosion can be estimated by using radionuclide Pb-210ex. However, radionuclide analysis cannot indicate the relative amounts of SS transported from each individual sub-basin to the downstream end. Thus, X-ray Fluorescence Analysis (XRF Analysis) can be considered as an alternative method to radionuclide analysis because the XRF Analysis can measure 21 chemical compositions, Na2O, MgO, Al2O3, SiO2, P2O5, SO3, Cl, K2O, CaO, TiO2, Cr2O3, MnO, Fe2O3, Co2O3, NiO, CuO, ZnO, Rb2O, SrO, BaO, and Y2O3 by using X-ray Fluorescence Analyzer. In June of 2007, high turbidity, which is more than 10,000 (NTU), was measured in the Oromushi River basin of Hokkaido in Japan. Therefore, this study aims to clarify the mechanism of the transport of SS in the Oromushi River basin. We measured chemical compositions of soil with diameter less than 63 ?m in the Oromushi River basin in order to pay attention to SS by using XRF. The Principal Component Analysis revealed that SiO2, Al2O3, Fe2O3, CaO and Na2O are the dominant chemical compositions. Although the predominant composition was the same in a river basin including the downstream end, significant differences were found in the pattern of chemical compositions. Therefore, by using the chemical compositions of SiO2, Al2O3, Fe2O3, CaO and Na2O, the Mixing Stable Isotope Analysis in R model (MixSIAR) based on Bayesian statistics was applied to estimate the transportation rate of SS from each sub-basin to the downstream end, which agreed with the field experiment results very well. As a result, spatial patterns of SS transportation rate are found to be strongly related to surface soil type.

  12. Gemas: issues from the comparison of aqua regia and X-ray fluorescence results

    NASA Astrophysics Data System (ADS)

    Dinelli, Enrico; Birke, Manfred; Reimann, Clemens; Demetriades, Alecos; DeVivo, Benedetto; Flight, Dee; Ladenberger, Anna; Albanese, Stefano; Cicchella, Domenico; Lima, Annamaria

    2014-05-01

    The comparison of analytical results from aqua regia (AR) and X-ray fluorescence spectroscopy (XRF) can provide information on soil processes controlling the element distribution. The GEMAS (GEochemical Mapping of Agricultural and grazing land Soils) agricultural soil database is used for this comparison. Analyses for the same suite of elements and parameters were carried out in the same laboratory under strict quality control procedures. Sample preparation has been conducted at the laboratory of the The comparison of analytical results from aqua regia (AR) and X-ray fluorescence spectroscopy (XRF) can provide information on soil processes controlling the element distribution in soil. The GEMAS (GEochemical Mapping of Agricultural and grazing land Soils) agricultural soil database, consisting of 2 x ca. 2100 samples spread evenly over 33 European countries, is used for this comparison. Analyses for the same suite of elements and parameters were carried out in the same laboratory under strict quality control procedures. Sample preparation has been conducted at the laboratory of the Geological Survey of the Slovak Republic, AR analyses were carried out at ACME Labs, and XRF analyses at the Federal Institute for Geosciences and Natural Resources, Germany Element recovery by AR is very different, ranging from <1% (e.g. Na, Zr) to > 80% (e.g. Mn, P, Co). Recovery is controlled by mineralogy of the parent material, but geographic and climatic factors and the weathering history of the soils are also important. Nonetheless, even the very low recovery elements show wide ranges of variation and spatial patterns that are affected by other factors than soil parent material. For many elements soil pH have a clear influence on AR extractability: under acidic soil conditions almost all elements tend to be leached and their extractability is generally low. It progressively increases with increasing pH and is highest in the pH range 7-8. Critical is the clay content of the soil that almost for all elements correspond to higher extractability with increasing clay abundance. Also other factors such as organic matter content of soil, Fe and Mn occurrence are important for certain elements or in selected areas. This work illustrates that there are significant differences in the extractability of elements from soils and addresses important influencing factors related to soil properties, geology, climate.

  13. Illuminating surface atoms in nanoclusters by differential X-ray absorption spectroscopy.

    PubMed

    Spanjers, Charles S; Senftle, Thomas P; van Duin, Adri C T; Janik, Michael J; Frenkel, Anatoly I; Rioux, Robert M

    2014-12-28

    We use differential extended X-ray absorption fine structure (?-EXAFS) to monitor the Ar-induced surface restructuring of silica-supported Pd nanoclusters (1 nm diameter) at 77 K. ?-EXAFS analysis shows 9 ± 2 nearest-neighbor Pd-Pd bonds expand by 0.104 ± 0.005 Å as a result of Ar adsorption. Atomistic molecular dynamics simulations provide evidence for a model in which Ar drives restructuring of under-coordinated Pd atoms, leading to an increased Pd-Pd bond length of surface Pd atoms with no change in overall nearest-neighbor Pd-Pd coordination number. Based on observations from the atomistic simulations, it is likely that under-coordinated atoms are trapped in metastable states at 77 K and Ar provides the kinetic energy needed to overcome the barrier for surface restructuring. Together, experiment and theory highlight the ability of ?-EXAFS to probe surface atoms of Pd nanoclusters. PMID:25054561

  14. Dynamical Diffraction Effect on Fluorescent X-Ray Emission in Absorbing Perfect Germanium Crystals in the Laue Geometry

    NASA Astrophysics Data System (ADS)

    Kaneko, Katsuhiro; Kashiwase, Yasuji; Kogiso, Motokazu; Mori, Masahiro; Minoura, Masayuki

    1993-02-01

    Intensity increase and decrease of fluorescent X-rays from the exit and entrance surfaces for the incident X-ray, respectively, are observed, when the 220 Bragg reflection of the incident radiation of wavelength 0.7093 Å is excited in perfect germanium crystals with ?D{=}9.57 and 16.0. The experiment is performed using a triple-crystal spectrometer and the radiation from a Mo target in a conventional X-ray tube monochromatized by the silicon symmetric 111 reflection and collimated by the triple 220 reflections in a channel-cut silicon crystal. The experimental intensity profiles agree well with those calculated using the intensity formulae given by Annaka (J. Phys. Soc. Jpn. Vol. 23 (1967) 372).

  15. TESTING EUV/X-RAY ATOMIC DATA FOR THE SOLAR DYNAMICS OBSERVATORY

    SciTech Connect

    Testa, Paola; Drake, Jeremy J. [Smithsonian Astrophysical Observatory, 60 Garden Street, MS 58, Cambridge, MA 02138 (United States); Landi, Enrico, E-mail: ptesta@cfa.harvard.edu [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109 (United States)

    2012-02-01

    The Atmospheric Imaging Assembly (AIA) and the Extreme-ultraviolet Variability Experiment (EVE) on board the Solar Dynamics Observatory (SDO) include spectral windows in the X-ray/EUV band. Accuracy and completeness of the atomic data in this wavelength range is essential for interpretation of the spectrum and irradiance of the solar corona, and of SDO observations made with the AIA and EVE instruments. Here, we test the X-ray/EUV data in the CHIANTI database to assess their completeness and accuracy in the SDO bands, with particular focus on the 94 A and 131 A AIA passbands. Given the paucity of solar observations adequate for this purpose, we use high-resolution X-ray spectra of the low-activity solar-like corona of Procyon obtained with the Chandra Low Energy Transmission Grating Spectrometer (LETGS). We find that while spectral models overall can reproduce quite well the observed spectra in the soft X-ray range {lambda} {approx}< 50 A, and at the EUV wavelengths {lambda} {approx}> 130 A, they significantly underestimate the observed flux in the 50-130 A wavelength range. The model underestimates the observed flux by a variable factor ranging from Almost-Equal-To 1.5, at short wavelengths below {approx}50 A, up to Almost-Equal-To 5-7 in the {approx}70-125 A range. In the AIA bands covered by LETGS, i.e., 94 A and 131 A, we find that the observed flux can be underestimated by large factors ({approx}3 and {approx}1.9, respectively, for the case of Procyon presented here). We discuss the consequences for analysis of AIA data and possible empirical corrections to the AIA responses to model more realistically the coronal emission in these passbands.

  16. Quantitative 3D elemental analysis inside plant roots by means of synchrotron confocal micro X-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Terzano, R.; Vekemans, B.; Tomasi, N.; Spagnuolo, M.; Schoonjans, T.; Vincze, L.; Pinton, R.; Cesco, S.; Ruggiero, P.

    2009-04-01

    The knowledge of the distribution and concentration of elements within plants is a fundamental step to better understand how these plants uptake specific elements from the medium of growth and how they manage acquisition and compartmentalisation of nutrients as well as toxic metals. For some elements, either nutrients or toxicants, it can be of relevance to know their concentration level within microscopic volumes in plant organs, where they are stored or accumulated. Usually, this type of microscopic analysis requires complex cutting procedures and extensive sample manipulations. In this research, the technique of synchrotron micro X-ray fluorescence in the confocal mode was applied to image the distribution of elements in selected key-planes of tomato roots without the need of any sample preparation, except washing and freeze-drying. Using this method, a first polycapillary lens focussed the X-ray beam with an energy of 12.4 keV down to a 20 µm beam that is penetrating the sample, and a second polycapillary half-lens, that was positioned at the detection side at 90 degrees to the first polycapillary, could then restrict further the view on this irradiated volume to a defined microscopic volume (typically 20x20x20 µm3) from which the induced fluorescent radiation is finally collected by the energy dispersive detector. In this way, it was possible to investigate the concentration levels of some elements such as K, Ca, Mn, Fe, Cu and Zn within the roots of tomato plants. The quantification was performed by means of a dedicated XRF Fundamental Parameter (FP) method in order to calculate the concentrations of trace elements within the analysed plants. Utilizing fundamental atomic parameters, the applied FP method is taking into account the influence of sample self-absorption and especially the specific detection processes by the polycapillary lens. Quantification was assessed and validated by using different standards: NIST SRM 1573a (trace elements in tomato leaves), NIST SRM 613 (trace elements in glass), and NIST SRM 1577b (trace elements in bovine liver). Accurate results could be obtained for Fe (within 2%), Cu and Zn (within 7%), and Mn (10%) while deviations ranging from 20 to 35% were observed for K and Ca, respectively. In particular, for an important nutrient such as Fe, concentration levels ranging from 370 µg g-1 down to 0.1 µg g-1 could be observed at different locations within the tomato roots.

  17. Depth profiling using total reflection X-ray fluorescence spectrometry alone and in combination with ion beam sputtering

    NASA Astrophysics Data System (ADS)

    Schwenke, H.; Knoth, J.; Günther, R.; Wiener, G.; Bormann, R.

    1997-07-01

    The capability of total reflection X-ray fluorescence spectrometry (TXRF) for depth profiling is examined by means of selected examples including organometallic layers, an implantation profile of arsenic in silicon and a layered nickel/cobalt structure. For structures without density differences that are deeper than 20 nm or so, and also for buried layers and for the examination of sharp interfaces, which require the highest resolution, two different combinations of ion beam sputtering with TXRF have been employed. A microsectioning technique was investigated in which samples were etched to a bevel shape and subsequently scanned by TXRF. A depth resolution of 2.5 nm was obtained. Alternatively, the so called "transfer technique" was investigated. This involves surface atoms being sputtered by an ion beam and immediately deposited on a silicon wafer rotated behind a slit which is moved in step with the sputter progress. Subsequently, the wafer is scanned by TXRF. Using this technique, the width of a coherent Ti/Al interface within a layered structure was measured to be 1.4 nm. The depth resolutions of the "microsectioning" and the "transfer" techniques are compared with data from RBS, XPS, SIMS and SNMS.

  18. Using Lasers and X-rays to Reveal the Motion of Atoms and Electrons

    SciTech Connect

    Bob Schoenlein

    2009-07-14

    July 7, 2009 Berkeley Lab summer lecture: The ultrafast motion of atoms and electrons lies at the heart of chemical reactions, advanced materials with exotic properties, and biological processes such as the first event in vision. Bob Schoenlein, Deputy Director for Science at the Advanced Light Source, will discuss how such processes are revealed by using laser pulses spanning a millionth of a billionth of a second, and how a new generation of light sources will bring the penetrating power of x-rays to the world of ultrafast science

  19. Application of X-ray diffraction dynamics to strong anomalous scattering region of an atom

    NASA Astrophysics Data System (ADS)

    Zhao, Zongyan; Han, Jiahua; Zhou, Shengming; Xu, Zhangcheng; Fukamachi, Tomoe; Negishi, Riichiro; Yoshizawa, Masami; Nakajima, Tetsuo

    1995-12-01

    This paper gives new formulae of X-ray dynamical diffraction for a plane-parallel crystal with finite thickness. These formulae are applicable when the ratio of the two absolute values, i.e. the real part of the atomic scattering factor and the imaginary part, is arbitrary. Based on these formulae, the results calculated in both the Bragg and the Laue cases show that the formulae not only agree well with originally theoretical predictions, but also provide an incentive for cases which have not been studied.

  20. Imaging of stroke: a comparison between X-ray fluorescence and magnetic resonance imaging methods

    PubMed Central

    Zheng, Weili; Haacke, E. Mark; Webb, Samuel M.; Nichol, Helen

    2013-01-01

    A dual imaging approach, combining magnetic resonance imaging to localize lesions and synchrotron rapid scanning X-ray fluorescence (XRF) mapping to localize and quantify calcium, iron and zinc was used to examine one case of recent stroke with hemorrhage and two cases of ischemia 3 and 7 years before death with the latter showing superficial necrosis. In hemorrhagic lesions, more Fe is found accompanied with less Zn. In chronic ischemic lesions, Fe, Zn and Ca are lower indicating that these elements are removed as the normal tissue dies and scar tissue forms. Both susceptibility and T2* maps were calculated to visualize iron in hemorrhages and validated by XRF Ca and Fe maps. The former was superior for imaging iron in hemorrhagic transformation and necrosis but did not capture ischemic lesions. In contrast, T2* could not differentiate Ca from Fe in necrotic tissue but did capture ischemic lesions, complementing the susceptibility mapping. The spatial localization, accurate quantitative data and elemental differentiation shown here could also be valuable for imaging other brain tissue damage with abnormal Ca and Fe content. PMID:22789844

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

    NASA Astrophysics Data System (ADS)

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

    2007-08-01

    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 fundamental parameters method. The concentrations of Cr, Ni, Cu, Zn and Pb were compared to the values from the European and Spanish legislation to evaluate the environmental risk and to classify the wastes as inert wastes or as wastes that have to be control land-filled. The results obtained demonstrate that these wastes can be considered as inert for the considered elements, apart from the concentration levels of Zn and Pb. Whilst Zn slightly overpasses the regulatory levels, Pb mean value exceeds three to six times the value to be considered as Class I potential land-filling material.

  2. Chemical analysis of used three-way catalysts by total reflection X-ray fluorescence.

    PubMed

    Fernández-Ruiz, R; Furió, M; Galisteo, F Cabello; Larese, C; López Granados, M; Mariscal, R; Fierro, J L G

    2002-11-01

    The methodology developed for evaluating, by total reflection X-ray fluorescence, the main elements in used three-way catalysts for cars after more than 59 000 km is described. The analytical method does not require chemical manipulation of the samples, is quick (30 min for sample preparation and 10 min for analysis), precise (between 1% and 10% of variation coefficient), and simple. The two catalytic monoliths contained in the cartridge of a car with more than 59,000 km have been analyzed. The mass relationships between the detected elements and Si, a component of the cordierite ceramic substrate, have been used to follow the axial and radial profiles of the elements. Information concerning the loss of active elements and the retention of contaminating elements as a consequence of the working conditions was attained by comparison between the results obtained for the used catalyst (59 000 km) with those of a fresh catalyst (0 km). The interface effect between the first and the second catalytic bricks was also studied. PMID:12433074

  3. Using Synchrotron X-ray Fluorescence Microprobes in the Study of Metal Homeostasis in Plants

    SciTech Connect

    Punshon, T.; Guerinot, M; Lanzirotti, A

    2009-01-01

    Background and Aims: This Botanical Briefing reviews the application of synchrotron X-ray fluorescence (SXRF) microprobes to the plant sciences; how the technique has expanded our knowledge of metal(loid) homeostasis, and how it can be used in the future. Scope: The use of SXRF microspectroscopy and microtomography in research on metal homeostasis in plants is reviewed. The potential use of SXRF as part of the ionomics toolbox, where it is able to provide fundamental information on the way that plants control metal homeostasis, is recommended. Conclusions: SXRF is one of the few techniques capable of providing spatially resolved in-vivo metal abundance data on a sub-micrometre scale, without the need for chemical fixation, coating, drying or even sectioning of samples. This gives researchers the ability to uncover mechanisms of plant metal homeostasis that can potentially be obscured by the artefacts of sample preparation. Further, new generation synchrotrons with smaller beam sizes and more sensitive detection systems will allow for the imaging of metal distribution within single living plant cells. Even greater advances in our understanding of metal homeostasis in plants can be gained by overcoming some of the practical boundaries that exist in the use of SXRF analysis.

  4. HIGH RESOLUTION X-RAY FLUORESCENCE MICRO-TOMOGRAPHY ON SINGLE SEDIMENT PARTICLES.

    SciTech Connect

    VINCZE,L.; VEKEMANS,B.; SZALOKI,I.; JANSSENS,K.; VAN GRIEKEN,R.; FENG,H.; JONES,K.W.; ADAMS,F.

    2002-07-29

    This work focuses on the investigation of the distribution of contaminants in individual sediment particles from the New York/New Jersey Harbor. Knowledge of the spatial distribution of the contaminants within the particles is needed to enable (1) more sophisticated approaches to the understanding of the fate and transport of the contaminants in the environment and (2) more refined methods for cleaning the sediments. The size of the investigated particles ranges from 30-80 microns. Due to the low concentration of the elements of interest and the microscopic size of the environmental particles in these measurements, the small size and high intensity of the analyzing X-ray beam was critical. The high photon flux at the ESRF Microfocus beam line (ID13) was used as the basis for fluorescence tomography to investigate whether the inorganic compounds are taken upon the surface organic coating or whether they are distributed through the volume of the grains being analyzed. The experiments were done using a 13 keV monochromatic beam of approximately 2 {micro}m in size having an intensity of 10{sup 10} ph/s, allowing absolute detection limits on the 0.04-1 fg level for Ti, Cr, Mn, Fe, Ni, and Zn.

  5. Comparison of gold leaf thickness in Namban folding screens using X-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Pessanha, Sofia; Madeira, Teresa I.; Manso, Marta; Guerra, Mauro; Le Gac, Agnès; Carvalho, Maria Luisa

    2014-09-01

    In this work, the thickness of the gold leaf applied in six Japanese folding screens is compared using a nondestructive approach. Four screens belonging to the Momoyama period (~1573-1603) and two screens belonging to the early Edo period (~1603-1868) were analyzed in situ using energy dispersive X-ray fluorescence, and the thickness of the applied gold leaf was evaluated using a methodology based on the attenuation of the different characteristic lines of gold in the gold leaf layer. Considering that the leaf may well not be made of pure gold, we established that, for the purpose of comparing the intensity ratios of the Au lines, layers made with gold leaf of high grade can be considered identical. The gold leaf applied in one of the screens from the Edo period was found to be thinner than the gold leaf applied in the other ones. This is consistent with the development of the beating technology to obtain ever more thin gold leafs.

  6. Using synchrotron X-ray fluorescence microprobes in the study of metal homeostasis in plants

    PubMed Central

    Punshon, Tracy; Guerinot, Mary Lou; Lanzirotti, Antonio

    2009-01-01

    Background and Aims This Botanical Briefing reviews the application of synchrotron X-ray fluorescence (SXRF) microprobes to the plant sciences; how the technique has expanded our knowledge of metal(loid) homeostasis, and how it can be used in the future. Scope The use of SXRF microspectroscopy and microtomography in research on metal homeostasis in plants is reviewed. The potential use of SXRF as part of the ionomics toolbox, where it is able to provide fundamental information on the way that plants control metal homeostasis, is recommended. Conclusions SXRF is one of the few techniques capable of providing spatially resolved in-vivo metal abundance data on a sub-micrometre scale, without the need for chemical fixation, coating, drying or even sectioning of samples. This gives researchers the ability to uncover mechanisms of plant metal homeostasis that can potentially be obscured by the artefacts of sample preparation. Further, new generation synchrotrons with smaller beam sizes and more sensitive detection systems will allow for the imaging of metal distribution within single living plant cells. Even greater advances in our understanding of metal homeostasis in plants can be gained by overcoming some of the practical boundaries that exist in the use of SXRF analysis. PMID:19182222

  7. Combined Fluorescence and X-Ray Tomography for Quantitative In Vivo Detection of Fluorophore

    PubMed Central

    Barber, W. C.; Lin, Y.; Nalcioglu, O.; Iwanczyk, J. S.; Hartsough, N. E.; Gulsen, G.

    2010-01-01

    Initial results from a novel dual modality preclinical imager which combines non-contact fluorescence tomography (FT) and x-ray computed tomography (CT) for preclinical functional and anatomical in vivo imaging are presented. The anatomical data from CT provides a priori information to the FT reconstruction to create overlaid functional and anatomical images with accurate localization and quantification of fluorophore distribution. Phantoms with inclusions containing Indocyanine-Green (ICG), and with heterogeneous backgrounds including iodine in compartments at different concentrations for CT contrast, have been imaged with the dual modality FT/CT system. Anatomical information from attenuation maps and optical morphological information from absorption and scattering maps are used as a priori information in the FT reconstruction. Although ICG inclusions can be located without the a priori information, the recovered ICG concentration shows 75% error. When the a priori information is utilized, the ICG concentration can be recovered with only 15% error. Developing the ability to accurately quantify fluorophore concentration in anatomical regions of interest may provide a powerful tool for in vivo small animal imaging. PMID:20082529

  8. Quantitative comparison of preparation methodologies for X-ray fluorescence microscopy of brain tissue.

    PubMed

    James, Simon A; Myers, Damian E; de Jonge, Martin D; Vogt, Stefan; Ryan, Chris G; Sexton, Brett A; Hoobin, Pamela; Paterson, David; Howard, Daryl L; Mayo, Sheridan C; Altissimo, Matteo; Moorhead, Gareth F; Wilkins, Stephen W

    2011-08-01

    X-ray fluorescence microscopy (XFM) facilitates high-sensitivity quantitative imaging of trace metals at high spatial resolution over large sample areas and can be applied to a diverse range of biological samples. Accurate determination of elemental content from recorded spectra requires proper calibration of the XFM instrument under the relevant operating conditions. Here, we describe the manufacture, characterization, and utilization of multi-element thin-film reference foils for use in calibration of XFM measurements of biological and other specimens. We have used these internal standards to assess the two-dimensional distribution of trace metals in a thin tissue section of a rat hippocampus. The data used in this study was acquired at the XFM beamline of the Australian Synchrotron using a new 384-element array detector (Maia) and at beamline 2-ID-E at the Advanced Photon Source. Post-processing of samples by different fixation techniques was investigated, with the conclusion that differences in solvent type and sample handling can significantly alter elemental content. The present study highlights the quantitative capability, high statistical power, and versatility of the XFM technique for mapping trace metals in biological samples, e.g., brain tissue samples in order to help understand neurological processes, especially when implemented in conjunction with a high-performance detector such as Maia. PMID:21533642

  9. Determination of halide impurities in ionic liquids by total reflection X-ray fluorescence spectrometry.

    PubMed

    Vander Hoogerstraete, Tom; Jamar, Steven; Wellens, Sil; Binnemans, Koen

    2014-04-15

    The determination and quantification of halide impurities in ionic liquids is highly important because halide ions can significantly influence the chemical and physical properties of ionic liquids. The use of impure ionic liquids in fundamental studies on solvent extraction or catalytic reactions can lead to incorrect experimental data. The detection of halide ions in solution by total reflection X-ray fluorescence (TXRF) has been problematic because volatile hydrogen halide (HX) compounds are formed when the sample is mixed with the acidic metal standard solution. The loss of HX during the drying step of the sample preparation procedure gives imprecise and inaccurate results. A new method based on an alkaline copper standard Cu(NH3)4(NO3)2 is presented for the determination of chloride, bromide, and iodide impurities in ionic liquids. The 1-butyl-3-methylimidazolium ([C4mim]) ionic liquids with the anions acetate ([C4mim][OAc]), nitrate ([C4mim][NO3]), trifluoromethanesulfonate ([C4mim][OTf]), and bis(trifluoromethylsulfonyl)imide ([C4mim][Tf2N]) were synthesized via a halide-free route and contaminated on purpose with known amounts of [C4mim]Cl, [C4mim]Br, [C4mim]I, or potassium halide salts in order to validate the new method and standard. PMID:24628670

  10. Iontophoresis: mechanism of action studied by potentiometry and x-ray fluorescence.

    PubMed

    Puttemans, F J; Massart, D L; Gilles, F; Lievens, P C; Jonckeer, M H

    1982-04-01

    Physiotherapists often apply electrotherapeutic treatments to the knees with sponges impregnated with potassium iodide (KI). To study the fate of iodine applied in this way, the amount of iodide (I-) that penetrates the skin was determined using an iodide-selective electrode. The I- uptake was shown to take place only when galvanic current was applied. Iontophoresis did not result in superficial migration of the applied ions on the skin from one pole to the other, but led to penetration into the skin. The hyperemia, which occurs at the zone of application during iontophoresis, did not affect the uptake of subsequent treatments. Only very slight differences in uptake were observed for each patient with sequential application, whereas the interindividual differences were more pronounced. Combined evidence from all experiments suggested that about 10% of the applied KI had penetrated the skin. X-ray fluorescence scans of the volunteers' thyroid gland, before and after a series of 10 iontophoretic treatments, to establish whether I- was taken up by the thyroid, showed that the average iodine content of the gland was increased by more than 30%. PMID:7082142

  11. Algorithms for a hand-held miniature x-ray fluorescence analytical instrument

    SciTech Connect

    Elam, W.T.; Newman, D.; Ziemba, F. [and others

    1998-12-31

    The purpose of this joint program was to provide technical assistance with the development of a Miniature X-ray Fluorescence (XRF) Analytical Instrument. This new XRF instrument is designed to overcome the weaknesses of spectrometers commercially available at the present time. Currently available XRF spectrometers (for a complete list see reference 1) convert spectral information to sample composition using the influence coefficients technique or the fundamental parameters method. They require either a standard sample with composition relatively close to the unknown or a detailed knowledge of the sample matrix. They also require a highly-trained operator and the results often depend on the capabilities of the operator. In addition, almost all existing field-portable, hand-held instruments use radioactive sources for excitation. Regulatory limits on such sources restrict them such that they can only provide relatively weak excitation. This limits all current hand-held XRF instruments to poor detection limits and/or long data collection times, in addition to the licensing requirements and disposal problems for radioactive sources. The new XRF instrument was developed jointly by Quantrad Sensor, Inc., the Naval Research Laboratory (NRL), and the Department of Energy (DOE). This report describes the analysis algorithms developed by NRL for the new instrument and the software which embodies them.

  12. Comparing Compositions of Modern Cast Bronze Sculptures: Optical Emission Spectroscopy Versus x-Ray Fluorescence Spectroscopy

    NASA Astrophysics Data System (ADS)

    Young, M. L.; Dunand, D. C.

    2015-05-01

    Bulk elemental compositions of 74 modern cast bronze sculptures from the collection at the Art Institute of Chicago, the Philadelphia Museum of Art, and the Rodin Museum (Philadelphia, PA) were determined using inductively coupled plasma-optical emission spectroscopy (ICP-OES) and a handheld x-ray fluorescence (XRF) spectrometer. The elemental compositions of the cast sculptures as measured previously by ICP-OES and presently by XRF are compared: A good match is found between the two methods for the base metal (Cu) and the two majority alloying elements (Zn and Sn). For both ICP-OES and XRF data, when the Zn composition is plotted versus the Sn composition, three discernable clusters are found that are related to the artist, foundry, casting date, and casting method; they consist of (A) high-zinc brass, (B) low-zinc, low-tin brass, and (C) low-zinc, tin bronze. Thus, our study confirms that the relatively fast, nondestructive XRF spectrometry can be used effectively over slower and invasive, but more accurate, ICP-OES to help determine a sculpture's artist, foundry, date of creation, date of casting, and casting method.

  13. High-energy-resolution grazing emission X-ray fluorescence applied to the characterization of thin Al films on Si

    NASA Astrophysics Data System (ADS)

    Kayser, Y.; Szlachetko, J.; Bana?, D.; Cao, W.; Dousse, J.-Cl.; Hoszowska, J.; Kubala-Kuku?, A.; Pajek, M.

    2013-10-01

    The grazing emission X-ray fluorescence (GEXRF) technique was applied to the analysis of different Al films, with nominal thicknesses in the range of 1 nm to 150 nm, on Si wafers. In GEXRF the sample volume from which the fluorescence intensity is detected is restricted to a near-surface region whose thickness can be tuned by varying the observation angle. This is possible because of the refraction of the fluorescence X-rays and the quite long emission paths within the probed sample. By recording the X-ray fluorescence signal for different shallow emission angles, defined relatively to the flat, smooth sample surface, the deposited Al surface layers of the different samples could be well characterized in terms of layer thickness, layer density, oxidation and surface roughness. The advantages offered by synchrotron radiation and the employed wavelength-dispersive detection setup were profited from. The GEXRF results retrieved were confirmed by complementary measurements. The experimental setup, the principles and advantages of GEXRF and the analysis of the recorded angular intensity profiles will be discussed in details.

  14. Ultraviolet Germicidal Irradiation and Its Effects on Elemental Distributions in Mouse Embryonic Fibroblast Cells in X-Ray Fluorescence Microanalysis

    DOE PAGESBeta

    Jin, Qiaoling; Vogt, Stefan; Lai, Barry; Chen, Si; Finney, Lydia; Gleber, Sophie-Charlotte; Ward, Jesse; Deng, Junjing; Mak, Rachel; Moonier, Nena; et al

    2015-02-23

    Rapidly-frozen hydrated (cryopreserved) specimens combined with cryo-scanning x-ray fluorescence microscopy provide an ideal approach for investigating elemental distributions in biological cells and tissues. However, because cryopreservation does not deactivate potentially infectious agents associated with Risk Group 2 biological materials, one must be concerned with contamination of expensive and complicated cryogenic x-ray microscopes when working with such materials. We employed ultraviolet germicidal irradiation to decontaminate previously cryopreserved cells under liquid nitrogen, and then investigated its effects on elemental distributions under both frozen hydrated and freeze dried states with xray fluorescence microscopy. We show that the contents and distributions of most biologicallymore »important elements remain nearly unchanged when compared with non-ultravioletirradiated counterparts, even after multiple cycles of ultraviolet germicidal irradiation and cryogenic x-ray imaging. This provides a potential pathway for rendering Risk Group 2 biological materials safe for handling in multiuser cryogenic x-ray microscopes without affecting the fidelity of the results.« less

  15. An Atomic-Scale X-ray View of Functional Oxide Films

    NASA Astrophysics Data System (ADS)

    Tung, I.-Cheng

    Complex oxides are a class of materials that exhibit a wide variety of physical functionalities, such as ferroelectricity, colossal magnetoresistance, mulitferroicity and superconductivity, with outstanding potential for meeting many of our technological demands. The primary objective of this dissertation is to understand the structural and electronic behavior of complex oxide ultrathin films subjected to confinement, lattice misfit and broken symmetry at the interface. In complex oxide ultrathin films, heteroepitaxial synthesis has evolved into a reliable strategy to engineer orbital-lattice interactions in correlated materials and led to new and entirely unexpected phenomena at their interfaces. I experimentally demonstrated that the bulk crystal symmetry directs the atomic and orbital responses adopted by coherently strained ultrathin films of RNiO3 (R = La, Nd) with detailed X-ray scattering, polarization-dependent X-ray absorption spectroscopy (XAS) and supported by a mathematical point group symmetry analysis, found that strain-stabilized phases maintain a ``memory'' of their bulk state. This topic, however, touched only upon the properties of such films. A fundamental challenge in this research area occurs before this and centers around the understanding of how to create high-quality films with arbitrary configurations. A longstanding challenge in the oxide thin film community has been the growth of An+1BnO3 n+1 Ruddlesden-Popper (RP) compounds. To understand this problem, we have utilized a newly constructed oxide MBE with in situ synchrotron X-ray scattering capability to study the initial growth of such layered oxides and track the dynamic evolution. X-ray results are supported by theoretical calculations that demonstrated the layered oxide films dynamically rearrange during growth, leading to structures that are highly unexpected, and suggest a general approach that may be essential for the construction of metastable RP phases with performing the first atomically controlled synthesis of single-crystalline La3Ni2O7. By building upon this knowledge, I have completed the first to date study of in situ surface X-ray scattering during homoepitaxial MBE growth of SrTiO3, which demonstrates codeposition is consistent with a 2D island growth mode with SrTiO3 islands, but shuttered deposition proceeds by the growth of SrO islands which then restructure into atomically flat SrTiO3 layer during the deposition of the TiO2. From this point, we have conducted a detailed microscopic study of epitaxial LaNiO3 ultrathin films grown on SrTiO3 (001) by using reactive MBE with in situ surface X-ray diffraction and ex situ soft XAS to explore the influence of polar mismatch on the resulting structural and electronic properties. Overall, this thesis highlights the power of artificial confinement to harness control over competing phases in complex oxides with atomic-scale precision.

  16. Element distribution in the brain sections of rats measured by synchrotron radiation X-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Liu, N. Q.; Zhang, F.; Wang, X. F.; Zhang, Z. Y.; Chai, Z. F.; Huang, Y. Y.; He, W.; Zhao, X. Q.; Zuo, A. J.; Yang, R.

    2004-02-01

    The concentration of trace elements in brain sections was measured by synchrotron radiation X-ray fluorescence. The relative concentration was calculated by means of the normalization of Compton scattering intensity approximately 22 keV, after the normalization for collecting time of X-ray spectrum and the counting of the ion chamber, and subtracting the contribution of the polycarbonate film for supporting sample. Furthermore, the statistical evaluation of the element distribution in various regions of the brain sections of the 20-day-old rats was tested. For investigating the distribution of elements in the brain of iodine deficient rats, Wistar rats were fed with iodine deficient diet and deionized water (ID group). The rats were fed the same iodine deficient diet, but drank KIO 3 solution as control (CT group). The results showed that the contents of calcium (Ca) in thalamus (TH) and copper (Cu) and iron (Fe) in cerebral cortex (CX) of ID rats were significantly lower than that of control rats, while the contents of phosphor (P), sulfur (S), potassium (K), rubidium (Rb), bromine (Br), chlorine (Cl), zinc (Zn), Ca and Cu of ID in hippocampus (H) and the contents of Br, Cl, Zn and Ca in cerebral cortex of ID rats were significantly higher. Especially, the difference of Br, Cl, Zn and Ca in H between ID and CT was more significant. The contents of all elements measured in H were higher than (or equal to) CX and/or TH for both groups, except low Cl of the control rats. Furthermore Zn and Cu contents along the hippocampal fissure in both groups were 1.5 ( P<0.001) and 0.87( P<0.03) times higher than in hippocampus, respectively. Considering the results of cluster analysis our study shows that the marked alterations in the spatial distribution of Zn and Ca of ID rats brain during brain development stages. In addition, the effect of the perfusion with 0.9% NaCl solution before taking brain on the distribution of elements in the brain sections was observed and discussed.

  17. Soft X-ray bremsstrahlung and fluorescent line production in the atmosphere by low energy electrons

    NASA Technical Reports Server (NTRS)

    Kraushaar, W. L.

    1974-01-01

    The effect of low energy quasi-trapped or precipitating electrons which impact on the counter windows of soft X-ray detectors are discussed. The errors caused by X-rays produced in the residual atmosphere above a rocket-borne detector because of the resemblance to X-rays of cosmic origin are examined. The design and development of counter windows which make it possible to identify the atmospherically produced X-rays are described. Curves are presented to show the following: (1) preliminary low energy electron data from Atmospheric Explorer C, (2) X-ray flux in electron-excited nitrogen and oxygen, (3) typical proportional counter response to low energy cosmic rays, and (4) proportional counter response to X-radiation produced by electrons incident upon a gas of oxygen to nitrogen number of 0.4.

  18. The atomic response to 10^18 W/cm^2 x-rays from the LCLS

    NASA Astrophysics Data System (ADS)

    Krässig, B.; Kanter, E. P.; March, A. M.; Li, Y.; Pratt, S. T.; Santra, R.; Southworth, S. H.; Young, L.; Rohringer, N.; Berrah, N.; Fang, L.; Höner, M.; Dimauro, L.; Doumy, G.; Roedig, C. A.; Bucksbaum, P. H.; Cryan, J. P.; Ghimire, S.; Glownia, J. M.; Reis, D. A.; Messerschmidt, M.; Bostedt, C.; Bozek, J. D.

    2010-03-01

    The goal of this experiment was to characterize the response of a prototypical atom, neon, to the unprecedented flux of microfocussed x-rays produced at the Linac Coherent Light Source (LCLS) at the SLAC Linear Accelerator Laboratory. In agreement with results from theoretical modeling, we find atoms inside the focal volume to undergo multiple successive ionization events, leading to fully stripped Ne^10+ at 2-keV x-ray energies, and charge states up to Ne^8+ below the K-ionization threshold. We also observe photoproduction of hollow neon ions through successive K-shell ionization on timescales shorter than Auger decay. We demonstrate intensity-induced x-ray transparency as a consequence of ever slower vacancy decay clocks limiting an ion's consecutive K absorption within a single 200-fs x-ray pulse.

  19. Complementary characterization of buried nanolayers by quantitative X-ray fluorescence spectrometry under conventional and grazing incidence conditions.

    PubMed

    Unterumsberger, Rainer; Pollakowski, Beatrix; Müller, Matthias; Beckhoff, Burkhard

    2011-11-15

    The determination of the thickness and elemental composition is an important part of the characterization of nanolayered structures. For buried nanolayers, X-ray fluorescence spectrometry is a qualified method for the thickness determination whereas conventional electron emission based methods may reach their limits due to rather restricted information depths. The aim of the presented investigation was the comparison of reference-free X-ray fluorescence spectrometry under conventional and grazing incidence conditions offering complementary information with respect to quantification reliability, elemental sensitivity, and layer sequences. For this purpose, buried boron-carbon layers with nominal thicknesses of 1, 3, and 5 nm have been studied using monochromatized undulator radiation in the laboratory of the Physikalisch-Technische Bundesanstalt (PTB) at the synchrotron radiation facility BESSY II. The results for the two beam geometries are compared and show particulate good agreements, thus encouraging the complementary use of both methodologies. PMID:21961904

  20. Asymmetri Distribution of Metals in the Xenopus Laevis Oocyte: a Synchrotron X-Ray Fluorescence Microprobe Study

    SciTech Connect

    Popescu, B.F.G.; Belak, Z.R.; Ignatyev, K.; Ovsenek, N.; Nichol, H.; /Saskatchewan U. /SLAC, SSRL

    2009-04-29

    The asymmetric distribution of many components of the Xenopus oocyte, including RNA, proteins, and pigment, provides a framework for cellular specialization during development. During maturation, Xenopus oocytes also acquire metals needed for development, but apart from zinc, little is known about their distribution. Synchrotron X-ray fluorescence microprobe was used to map iron, copper, and zinc and the metalloid selenium in a whole oocyte. Iron, zinc, and copper were asymmetrically distributed in the cytoplasm, while selenium and copper were more abundant in the nucleus. A zone of high copper and zinc was seen in the animal pole cytoplasm. Iron was also concentrated in the animal pole but did not colocalize with zinc, copper, or pigment accumulations. This asymmetry of metal deposition may be important for normal development. Synchrotron X-ray fluorescence microprobe will be a useful tool to examine how metals accumulate and redistribute during fertilization and embryonic development.

  1. Asymmetric Distribution of Metals in the Xenopus Laevis Oocyte: a Synchrotron X-Ray Fluorescence Microprobe Study

    SciTech Connect

    Popescu, B.F.Gh.; Belak, Z.R.; Ignatyev, K.; Ovsenek, N.; Nichol, H.

    2009-06-04

    The asymmetric distribution of many components of the Xenopus oocyte, including RNA, proteins, and pigment, provides a framework for cellular specialization during development. During maturation, Xenopus oocytes also acquire metals needed for development, but apart from zinc, little is known about their distribution. Synchrotron X-ray fluorescence microprobe was used to map iron, copper, and zinc and the metalloid selenium in a whole oocyte. Iron, zinc, and copper were asymmetrically distributed in the cytoplasm, while selenium and copper were more abundant in the nucleus. A zone of high copper and zinc was seen in the animal pole cytoplasm. Iron was also concentrated in the animal pole but did not colocalize with zinc, copper, or pigment accumulations. This asymmetry of metal deposition may be important for normal development. Synchrotron X-ray fluorescence microprobe will be a useful tool to examine how metals accumulate and redistribute during fertilization and embryonic development.

  2. Double K-shell photoionization and hypersatellite x-ray transitions of 12?Z?23 atoms

    NASA Astrophysics Data System (ADS)

    Hoszowska, J.; Dousse, J.-Cl.; Cao, W.; Fennane, K.; Kayser, Y.; Szlachetko, M.; Szlachetko, J.; Kav?i?, M.

    2010-12-01

    Single-photon double K-shell ionization of low-Z neutral atoms in the range 12?Z?23 is investigated. The experimental method was based on measurements of the high-resolution K?h hypersatellite x-ray spectra following the radiative decay of the K-shell double-vacancy states excited by monochromatic synchrotron radiation. The photon energy dependence of the double K-shell ionization was measured over a wide range of photon energies from threshold up to and beyond the maximum of the double-to-single photoionization cross section ratios. From the high-resolution x-ray emission spectra the energies and linewidths of the hypersatellite transitions, as well as the K?1h:K?2h intensity ratios, were determined. The relative importance of the initial-state and final-state electron-electron interactions to the K-shell double photoionization is addressed. Physical mechanisms and scaling laws of the K-shell double photoionization are examined. A semiempirical universal scaling of the double-photoionization cross sections with the effective nuclear charge for neutral atoms in the range 2?Z?47 is established.

  3. Use of portable X-ray fluorescence spectrometry for environmental quality assessment of peri-urban agriculture

    Microsoft Academic Search

    David C. Weindorf; Yuanda Zhu; Somsubhra Chakraborty; Noura Bakr; Biao Huang

    Urban expansion into traditional agricultural lands has augmented the potential for heavy metal contamination of soils. This\\u000a study examined the utility of field portable X-ray fluorescence (PXRF) spectrometry for evaluating the environmental quality\\u000a of sugarcane fields near two industrial complexes in Louisiana, USA. Results indicated that PXRF provided quality results\\u000a of heavy metal levels comparable to traditional laboratory analysis. When

  4. Factors affecting in vivo measurement precision and accuracy of 109Cd K x-ray fluorescence measurements

    Microsoft Academic Search

    Fiona E. McNeill; Lynette Stokes; David R. Chettle; Wendy E. Kaye

    1999-01-01

    109Cd K x-ray fluorescence (XRF) measurement systems from two research centres were used to measure tibia lead content in a population (n = 530) of young adults. The group mean bone lead contents (SEM) determined by McMaster University (n = 214) and the University of Maryland (n = 316) were 2.800.51 and 2.330.50 g Pb\\/(g bone mineral) respectively. The mean

  5. Assessment of Occupational Exposure to Manganese and Other Metals in Welding Fumes by Portable X-ray Fluorescence Spectrometer

    Microsoft Academic Search

    Wisanti Laohaudomchok; Jennifer M. Cavallari; Shona C. Fang; Xihong Lin; Robert F. Herrick; David C. Christiani; Marc G. Weisskopf

    2010-01-01

    Elemental analysis of welding fume samples can be done using several laboratory-based techniques. However, portable measurement techniques could offer several advantages. In this study, we sought to determine whether the portable X-ray fluorescence spectrometer (XRF) is suitable for analysis of five metals (manganese, iron, zinc, copper, and chromium) on 37-mm polytetrafluoroethylene filters. Using this filter fitted on a cyclone in

  6. Novel Technique for Improving the Signal-to-Background Ratio of X-ray Absorption Near-Edge Structure Spectrum in Fluorescence Mode and Its Application to the Chemical State Analysis of Magnesium Doped in GaN

    NASA Astrophysics Data System (ADS)

    Yonemura, Takumi; Iihara, Junji; Saito, Yoshihiro; Ueno, Masaki

    2013-12-01

    A novel measurement technique for an X-ray absorption near-edge structure (XANES) for magnesium (Mg) doped in gallium nitride (GaN) has been developed. XANES spectra from Mg at very low concentrations of 1 ×1018/cm3 doped in GaN have successfully been obtained by optimizing the region of interest (ROI) and by using highly brilliant synchrotron radiation X-rays of SPring-8. The ROI is the limited energy region from an X-ray fluorescence spectrum to elicit signals of particular atoms. Using this new technique, we have investigated the effect of the annealing process for Mg-doped GaN on the XANES spectra. It has been found that the XANES spectra of Mg significantly changed as the annealing temperature increased. This indicates that the local structure around Mg atoms in GaN was modified by the annealing process.

  7. Determination of metal-cofactors in enzyme complexes by total-reflection X-ray fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Wittershagen, A.; Rostam-Khani, P.; Klimmek, O.; Groß, R.; Zickermann, V.; Zickermann, I.; Gemeinhardt, S.; Kröger, A.; Ludwig, B.; Kolbesen, B. O.

    1997-07-01

    The determination of metal-cofactors and their molar concentrations is an important requirement for the characterisation of metalloproteins and a challenge regarding the capabilities of trace analytical methods. In this respect, total-reflection X-ray fluorescence spectrometry offers many advantages for the determination of trace elements in enzymes, as compared to other well known analytical techniques such as flame atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry (ICP-AES), because of the significantly smaller amounts of sample required. Without any decomposition, elements like P, S, Fe, Ni, Cu, Zn, Mn and Mo could be determined with high accuracy, in spite of the large bio-organic matrix. The enzymes (polysulphide reductase and hydrogenase of the rumen bacterium Wolinella succinogenes, and the cytochrome c oxidase and quinol oxidase of the soil bacterium Paracoccus denitrificans) were transferred from their usual salt-buffer into a solution of 100 mmol l -1 tris(hydroxymethyl)aminomethane (tris)-acetate containing an appropriate detergent. By this procedure, an improved signal-to-noise ratio is obtained. The polysulphide reductase was found to contain copper as a hitherto existing unknown cofactor. The enzyme contains a stretch of amino acids that are typical of copper proteins and thus confirm the presence of this element. Furthermore, the data concerning cytochrome c oxidase from Paracoccus denitrificans are in good agreement with published values obtained by ICP-AES. Also, results from measurements with the quinol oxidase from the same bacterium agree with the expected values. The investigations lead to the conclusion that the method is well suited to the quantitative determination of metals in enzymes, in particular their molar fractions, and requires only small amounts of the biological sample without any extensive pretreatment.

  8. Total-reflection X-ray fluorescence — a tool to obtain information about different air masses and air pollution

    NASA Astrophysics Data System (ADS)

    Schmeling, Martina

    2001-11-01

    Atmospheric aerosols are solid particles dissolved in air and change their chemical composition frequently depending on various parameters. In order to identify regional air circulation atmospheric aerosol filter samples were taken at Loyola University Chicago's Lake Shore Campus during the months of July and August 2000 with sampling times ranging between 1 and 2 h. The samples were digested in a microwave oven and analyzed by total-reflection X-ray fluorescence (TXRF) spectrometry. One diurnal variation comprising five consecutive sampling events was selected and discussed as well as 4 days experiencing different meteorology were compared to exemplify the variation in trace elemental concentration according to air mass movements and highlight the capability of total-reflection X-ray fluorescence analysis. It was found that due to changes in meteorological conditions particularly wind direction and wind speed, trace elemental compositions varied rapidly and could be used to distinguish between 'Lake Michigan air' and 'metropolitan Chicago air' on such short-term time scale like one hour. Back trajectory analysis was applied to support and corroborate the results. The outcome of this study clearly shows that total-reflection X-ray fluorescence is an optimal tool for analysis of atmospheric aerosols.

  9. Accurate measurement and physical insight: The X-ray extended range technique for fundamental atomic physics, condensed matter research and biological sciences

    NASA Astrophysics Data System (ADS)

    Chantler, C. T.

    2010-02-01

    Research in core physics or atomic and condensed matter science is increasingly relevant for diverse fields and are finding application in chemistry, engineering and biological sciences, linking to experimental research at synchrotrons, reactors and specialised facilities. Over recent synchrotron experiments and publications we have developed methods for measuring the absorption coefficient far from the edge and in the XAFS (X-ray absorption fine structure) region in neutral atoms, simple compounds and organometallics reaching accuracies of below 0.02%. This is 50-500 times more accurate than earlier methods, and 50-250 times more accurate than claimed uncertainties in theoretical computations for these systems. The data and methodology are useful for a wide range of applications, including major synchrotron and laboratory techniques relating to fine structure, near-edge analysis and standard crystallography. Experiments are sensitive to theoretical and computational issues, including correlation between convergence of electronic and atomic orbitals and wavefunctions. Hence, particularly in relation to the popular techniques of XAFS and XANES (X-ray absorption near-edge structure), this development calls for strong theoretical involvement but has great applications in solid state structural determination, catalysis and enzyme environments, active centres of biomolecules and organometallics, phase changes and fluorescence investigations and others. We discuss key features of the X-ray extended range technique (XERT) and illustrate applications.

  10. Nonresonance Compton scattering of an X-ray photon by a Ni-like atomic ion

    NASA Astrophysics Data System (ADS)

    Khopersky, A. N.; Nadolinsky, A. M.; Ikoeva, K. Kh.; Khoroshavina, O. A.; Kasprzhitskii, A. S.

    2012-01-01

    The absolute values and the shape of the double differential cross section for nonresonance Compton scattering of an X-ray photon by an atomic ion with d symmetry in the core are studied theoretically beyond the impulse approximation for the example of the Ni-like atomic ions Zn2+, Kr8+, and Mo14+. It is established that, as the nuclear charge of an ion increases, (a) in all the scattering channels, the leading harmonics of transition to states of the continuous spectrum are concentrated and (b) the integral intensities of nonresonance Compton scattering are increasingly redistributed to the energy region of resonance Lands-berg-Mandelstam-Raman scattering between the threshold of termination of the Compton profile and the line of elastic (Thomson and Rayleigh) scattering. The calculated results are predictive in character.

  11. Projections of local atomic structure revealed by wavelet analysis of x-ray absorption anisotropy P. Korecki,1,* D. V. Novikov,2 and M. Tolkiehn2

    E-print Network

    Korecki, Pawe³

    analysis of polychromatic beam x-ray absorption anisotropy for local structure imaging. DOI: 10.1103/PhysProjections of local atomic structure revealed by wavelet analysis of x-ray absorption anisotropy P in an experiment a wavelet transform approach for analysis of x-ray absorption anisotropy XAA patterns recorded

  12. Analysis of limestones and dolomites by x-ray fluorescence spectroscopy

    SciTech Connect

    Wheeler, B.D.

    1999-07-01

    Sources of calcium are generally widespread and quite extensive. These sources are limestone, dolomite, marl, chalk, and oyster shell. Cement plants account for nearly half of the demand, while two hundred lime plants in the US and Puerto Rico consume about twenty five percent. Since the chemical composition of the limestone and other sources of calcium is critical in the cement and lime industry, particularly for the deleterious compounds such as sodium oxide, Na{sub 2}O, magnesium oxide, MgO, phosphorus pentoxide, P{sub 2}O{sub 5}, and potassium oxide, K{sub 2}O, accurate determinations are critical. Due to the tonnage per hour, these determinations must be made rapidly and accurately. X-ray fluorescence can thereby satisfy this need for accuracy and also precision. Production of lime is performed by calcining limestone or dolomite in which the industry is generally located and concentrated in the States of Michigan and Pennsylvania. The resulting product is quicklime, CaO, and hydrated lime, Ca(OH){sub 2}. Substantial amounts of quicklime is further processed into calcium carbide in order to produce acetylene gas. In this case, the determination of P{sub 2}O{sub 5} is critical since minor quantities of phosphorus in acetylene gas can cause premature explosions. Other uses for lime are well known in the treatment of water, the paper and pulp industry, and in the steel industry for the production of slag to remove impurities. Dolomitic lime is heavily utilized in the manufacture of magnesite refractories by reacting dolomitic lime with brines from the Michigan Basin to produce magnesium oxide, MgO, and calcium chloride, CaCl{sub 2}. Sample preparation for these materials usually is performed by grinding and pelletizing or fusion with lithium-tetra-borate, Li{sub 2}B{sub 4}O{sub 7}.

  13. Direct analysis of human blood (mothers and newborns) by energy dispersive X-ray fluorescence.

    PubMed

    Custódio, P J; Carvalho, Maria Luisa; Nunes, F; Pedroso, S; Campos, A

    2005-01-01

    This work is an application of energy dispersive X-ray fluorescence (EDXRF) as analytical technique for trace element determination in human tissues. Potassium (K), calcium (Ca), iron (Fe), copper (Cu), zinc (Zn), bromine (Br), rubidium (Rb) and lead (Pb) were determined directly in blood samples from 66 mothers at delivery after full-term pregnancies. The corresponding 66 cord-blood samples of the newborns were also analysed, in order to find element correlations between maternal and newborn blood at birth. The studied samples were obtained from mothers aged between 15 and 39 years old, the gestational age being between 35 and 41 weeks and the newborns' weight between 2.310 and 4.310 kg. Samples were lyophilised and analysed without any chemical treatment. Very low levels of Pb were found both in maternal and fetal cord blood samples. Cu values ranged from 3 to 13 microg g-1, both for mothers and children. A correlation between Cu and Fe concentrations in maternal and fetal cord blood was found. Zn is considered as one of the key elements in newborn health. Concentrations between 10 and 40 microg g-1 were measured. A positive correlation between Br levels in mothers and children was observed. Positive correlations for mothers were observed between Zn and Rb as well as K and Fe. The corresponding correlations in fetal cord blood samples were not observed, however positive correlations were found between Ca and K; Cu and Fe. The mean concentrations for each element were similar in maternal and in fetal cord blood, except for Cu and Zn, being higher in maternal samples. No correlations between element concentrations and pathologies of the mothers were observed. PMID:16325530

  14. X-ray fluorescence analysis of rare earth elements in rocks using low dilution glass beads.

    PubMed

    Nakayama, Kenichi; Nakamura, Toshihiro

    2005-07-01

    Major and trace elements (Na, Mg, Al, Si, P, K, Ca, Ti, Mn, Fe, Rb, Sr, Y, Zr, La, Ce, Pr, Nd, Sm, Gd, Dy, Th and U) in igneous rocks were assayed with fused lithium borate glass beads using X-ray fluorescence spectrometry. Low dilution glass beads, which had a 1:1 sample-to-flux ratio, were prepared for determination of rare earth elements. Complete vitrification of 1:1 mixture required heating twice at 1200 degrees C with agitation. Extra pure reagents containing determinants were used for calibrating standards instead of the rock standard. The calibration curves of the 23 elements showed good linearity. Furthermore, the lower limits of detection corresponding to three times the standard deviation for blank measurements were 26 mass ppm for Na2O, 6.7 for MgO, 4.5 for Al2O3, 4.5 for SiO2, 18 for P2O5, 1.1 for K2O, 4.0 for CaO, 3.9 for TiO2, 1.6 for MnO, 0.8 for Fe2O3, 0.5 for Rb, 0.2 for Sr, 0.4 for Y, 0.5 for Zr, 3.3 for La, 6.5 for Ce, 2.7 for Pr, 2.1 for Nd, 1.7 for Sm, 0.7 for Gd, 2.7 for Dy, 0.5 for Th, and 0.6 for U. Using the present method, we determined the contents of these 23 elements in four rhyolitic and granitic rocks from Japan. PMID:16038502

  15. Measuring plant available phosphorus using diffusive gradients in thin films and x-ray fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Rothwell, Shane; Surridge, Ben; Dodd, Ian; Quinton, John; Zhang, Hao

    2015-04-01

    Global concerns of phosphorus (P) deficiency limiting crop yields, and finite supplies of mineral P reserves, suggest a need to maximise P use efficiency in agriculture. To accurately predict the availability of soil P to crops, and subsequent P fertiliser recommendations, soil P tests must determine only the P that will be accessed and utilised by a crop. However, there is growing doubt regarding the ability of current extraction techniques (water, bicarbonate, resin) to accurately determine plant-available P across a range of soils. Indeed, the most widely-used test (Olsen P) across all soil types was only designed for alkaline soils and therefore it is inappropriate as a national standard soil test. Thus, there is an urgent need to develop a standard approach to measuring P availability applicable across a range of soil types. Diffusive Gradients in Thin Films (DGT) may be a more accurate technique for measuring the P available to plants than P measured using current extraction techniques because the measurement responds to both soil solution P and the P rapidly resupplied from the solid phase. However, elution by acid extraction of P retained within the resin gel of a DGT device, followed by analysis via inductively coupled plasma-based techniques, typically results in a delay of several days between DGT deployment and reporting of P concentrations. This is currently a significant constraint on the adoption of DGT to determine plant-available P in agricultural soils. Our research seeks to develop a novel combination of two existing techniques, DGT with portable x-ray fluorescence spectrometry (pXRF) to achieve rapid, non-destructive analysis of P within a DGT device, thus significantly reducing the length of time between DGT deployment and the final determination of plant-available P in agricultural soils. We aim to develop DGT-pXRF as a robust routine analytical procedure suitable for analysis of plant available P in a wide range of agricultural soil types.

  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. X-ray fluorescence imaging: a new tool for studying manganese neurotoxicity.

    PubMed

    Robison, Gregory; Zakharova, Taisiya; Fu, Sherleen; Jiang, Wendy; Fulper, Rachael; Barrea, Raul; Marcus, Matthew A; Zheng, Wei; Pushkar, Yulia

    2012-01-01

    The neurotoxic effect of manganese (Mn) establishes itself in a condition known as manganism or Mn induced parkinsonism. While this condition was first diagnosed about 170 years ago, the mechanism of the neurotoxic action of Mn remains unknown. Moreover, the possibility that Mn exposure combined with other genetic and environmental factors can contribute to the development of Parkinson's disease has been discussed in the literature and several epidemiological studies have demonstrated a correlation between Mn exposure and an elevated risk of Parkinson's disease. Here, we introduce X-ray fluorescence imaging as a new quantitative tool for analysis of the Mn distribution in the brain with high spatial resolution. The animal model employed mimics deficits observed in affected human subjects. The obtained maps of Mn distribution in the brain demonstrate the highest Mn content in the globus pallidus, the thalamus, and the substantia nigra pars compacta. To test the hypothesis that Mn transport into/distribution within brain cells mimics that of other biologically relevant metal ions, such as iron, copper, or zinc, their distributions were compared. It was demonstrated that the Mn distribution does not follow the distributions of any of these metals in the brain. The majority of Mn in the brain was shown to occur in the mobile state, confirming the relevance of the chelation therapy currently used to treat Mn intoxication. In cells with accumulated Mn, it can cause neurotoxic action by affecting the mitochondrial respiratory chain. This can result in increased susceptibility of the neurons of the globus pallidus, thalamus, and substantia nigra pars compacta to various environmental or genetic insults. The obtained data is the first demonstration of Mn accumulation in the substantia nigra pars compacta, and thus, can represent a link between Mn exposure and its potential effects for development of Parkinson's disease. PMID:23185282

  18. Combining ?X-ray fluorescence, ?XANES and ?XRD to shed light on Zn2+ cations in cartilage and meniscus calcifications.

    PubMed

    Dessombz, Arnaud; Nguyen, Christelle; Ea, Hang-Korng; Rouzière, Stephan; Foy, Eddy; Hannouche, Didier; Réguer, Solene; Picca, Frederic-Emmanuel; Thiaudière, Dominique; Lioté, Frédéric; Daudon, Michel; Bazin, Dominique

    2013-10-01

    We aimed to examine the presence of Zn, a trace element, in osteoarthritis (OA) cartilage and meniscus from patients undergoing total knee joint replacement for primary OA. We mapped Ca(2+) and Zn(2+) at the mesoscopic scale by X-ray fluorescence microanalysis (?X-ray) to determine the spatial distribution of the 2 elements in cartilage, ?X-ray absorption near edge structure spectroscopy to identify the Zn species, and ?X-ray diffraction to determine the chemical nature of the calcification. Fourier transform infrared spectroscopy was used to determine the chemical composition of cartilage and meniscus. Ca(2+) showed a heterogeneous spatial distribution corresponding to the calcifications within cartilage (or meniscus) or at their surface. At least 2 Zn(2+) species were present: the first may correspond to Zn embedded in protein (different Zn metalloproteins are known to prevent calcification in biological tissues), and the second may be associated with a Zn trap in or at the surface of the calcification. Calcification present in OA cartilage may significantly modify the spatial distribution of Zn; part of the Zn may be trapped in the calcification and may alter the associated biological function of Zn metalloproteins. PMID:23582484

  19. CCMR: Atomic Scale Theory of Real-Time X-ray Signatures in Pulsed Laser Deposition

    NSDL National Science Digital Library

    Handford, Christina G.

    2005-08-17

    Pulsed laser deposition (PLD) uses timed laser pulses to blast a target surface causing a plume of material to be discharged from the target. The plume of material then collides with the substrate surface on which the material is being grown. One thing pulsed laser deposition is used for is growing thin films of complex oxide crystals. In an experiment by Aaron Fleet, et al., a smoothing mechanism is found to be present during PLD of SrTiO3. Via real time x-ray diffraction data from the G3 facility at CHESS, the smoothing mechanism is found to vary with the step density of the thin film. These findings are the inspiration for this theoretical research project designed to study these step phenomena on the atomic level. The project focuses on two possibilities for the experimentally observed trend. One is the possibility of a difference in behavior of the collisions when hitting near a step, as opposed to a flat surface, and two is the possibility that there is a difference in the x-ray signatures only due to the presence of steps on a relaxed surface. These two possibilities are studied and compared to determine if they are relevant to the smoothing mechanism.

  20. Development of a standard for the method of x-ray fluorescence spectral analysis integrated into the international system of estimation of the quality of refractory products

    Microsoft Academic Search

    S. A. Suvorov; Yu. G. Lifanov; E. A. Vikhrov

    2011-01-01

    A program for the development of the national standard for the method of x-ray fluorescence spectral analysis of refractory\\u000a materials and ensuring its conformity to the international standard ISO 12677–2003 is created.

  1. [Energy dispersive x-ray fluorescence spectrometry--a forensic chemistry method for detection of bullet metal residue in gunshot wounds].

    PubMed

    Havel, J; Zelenka, K

    2003-04-01

    The article describes using of energo-dispersive X-ray fluorescence spectrometry (EDXRF) as the forensic method as the tool for detection of metals (gunshot residues--GSR) in connection with gunshot-wounds of persons. PMID:12874887

  2. Ordered many-electron motions in atoms and x-ray lasers. [Subpicosecond ultraviolet laser radiation

    SciTech Connect

    Rhodes, C.K.

    1986-01-01

    Subpicosecond ultraviolet laser technology is enabling the exploration of nonlinear atomic interactions with electric field strengths considerably in excess of an atomic unit. As this regime is approached, experiments studying multiple ionization, photoelectron energy spectra, and harmonically produced radiation all exhibit strong nonlinear coupling. Peak total energy transfer rates on the order of approx.2 x 10/sup -4/ W/atom have been observed at an intensity of approx.10/sup 16/ W/cm/sup 2/, and it is expected that energy transfer rates approaching approx.0.1 to 1 W/atom will occur under more extreme conditions for which the ultraviolet electric field E is significantly greater than e/a/sub 0//sup 2/. In this high intensity regime, a wide range of new nonlinear phenomena will be open to study. These will include the possibility of ordered driven motions in atoms, molecules, and plasmas, mechanisms involving collisions, and relativistic processes such as electron-positron pair production. An understanding of these physical interactions may provide a basis for the generation of stimulated emission in the x-ray range. 100 refs., 8 figs.

  3. Depth profiling of element concentrations in stratified materials by confocal microbeam X-ray fluorescence spectrometry with polychromatic excitation.

    PubMed

    Wrobel, Pawel; Wegrzynek, Dariusz; Czyzycki, Mateusz; Lankosz, Marek

    2014-11-18

    The confocal microbeam X-ray fluorescence technique is a well-established analytical tool that is widely used for qualitative and quantitative analysis of stratified materials. There are several different reconstruction methods dedicated to this type of samples. However, these methods are applicable with monochromatic excitation only. The full description of matrix effects and geometrical effects for polychromatic X-ray photons in confocal geometry is a demanding task. In the present paper, this problem was overcome by the use of effective energy approximation. The reduction of the whole energy dimension into one effective value eliminates the necessity of integration over the primary beam energy range for a number of basic parameters. This simplification is attainable without loss of the accuracy of analysis. The proposed approach was validated by applying it to the reconstruction of element concentration depth profiles of stratified standard samples measured with tabletop confocal microbeam X-ray fluorescence setup and by comparing the obtained results of two independent algorithms. PMID:25307861

  4. Calibration of reference materials for total-reflection X-ray fluorescence analysis by heavy ion backscattering spectrometry

    NASA Astrophysics Data System (ADS)

    Werho, D.; Gregory, R.; Schauer, S.; Liu, X.; Carney, G.; Banks, J.; Knapp, J.; Doyle, B.; Diebold, A. C.

    1997-07-01

    Total-reflection X-ray fluorescence (TXRF) is widely used for the control of metallic contamination caused by surface preparation processes and silicon materials. At least three companies supply a variety of TXRF systems to the silicon integrated circuit (IC) community, and local calibration of these systems is required for their day to day operation. Differences in local calibration methods have become an issue in the exchange of information between IC manufacturers' different FABs (Fabrication Facility) and also between silicon suppliers and IC FABs. The question arises whether a universal set of fluorescence yield curves can be used by these different systems to scale system sensitivity from a single element calibration for calculation of elemental concentrations. This is emphasized by the variety of experimental conditions that are reported for TXRF data (e.g. different angles of incidence for the same X-ray source, different X-ray sources, etc.). It appears that an instrumental factor is required. We believe that heavy ion backscattering spectrometry (HIBS) provides a fundamental method of calibrating TXRF reference materials, and can be used in calculating this instrumental factor. In this paper we briefly describe the HIBS system at the Sandia National Laboratories HIBS User Facility and its application to the calibration of TXRF reference materials. We will compare HIBS and TXRF mapping capabilities and discuss the issues associated with the restrictions of some older TXRF sample stages. We will also discuss Motorola's cross-calibration of several TXRF systems using different elements as references.

  5. Selenium preferentially accumulates in the eye lens following embryonic exposure: a confocal X-ray fluorescence imaging study.

    PubMed

    Choudhury, Sanjukta; Thomas, Jith K; Sylvain, Nicole J; Ponomarenko, Olena; Gordon, Robert A; Heald, Steve M; Janz, David M; Krone, Patrick H; Coulthard, Ian; George, Graham N; Pickering, Ingrid J

    2015-02-17

    Maternal transfer of elevated selenium (Se) to offspring is an important route of Se exposure for fish in the natural environment. However, there is a lack of information on the tissue specific spatial distribution and speciation of Se in the early developmental stages of fish, which provide important information about Se toxicokinetics. The effect of maternal transfer of Se was studied by feeding adult zebrafish a Se-elevated or a control diet followed by collection of larvae from both groups. Novel confocal synchrotron-based techniques were used to investigate Se within intact preserved larvae. Confocal X-ray fluorescence imaging was used to compare Se distributions within specific planes of an intact larva from each of the two groups. The elevated Se treatment showed substantially higher Se levels than the control; Se preferentially accumulated to highest levels in the eye lens, with lower levels in the retina, yolk and other tissues. Confocal X-ray absorption spectroscopy was used to determine that the speciation of Se within the eye lens of the intact larva was a selenomethionine-like species. Preferential accumulation of Se in the eye lens may suggest a direct cause-and-effect relationship between exposure to elevated Se and Se-induced ocular impairments reported previously. This study illustrates the effectiveness of confocal X-ray fluorescence methods for investigating trace element distribution and speciation in intact biological specimens. PMID:25607235

  6. Coherent X-ray imaging: bridging the gap between atomic and micro-scale investigations.

    PubMed

    Stampanoni, Marco; Menzel, Andreas; Watts, Ben; Mader, Kevin S; Bunk, Oliver

    2014-01-01

    We present a review of state-of-the art X-ray imaging techniques based on partially coherent synchrotron radiation. Full-field X-ray tomography, X-ray ptychography, scanning small-angle X-ray scattering, and scanning transmission X-ray microscopy are imaging techniques that gather structural information at spatial resolution ranging from several microns to a few tens of nanometers in both real- and reciprocal space. These methods exploit contrast mechanisms based on absorption, phase, and spectroscopic signals. We provide examples of how these techniques can be applied to address scientific questions ranging from imaging of biological samples, to foam rheology, and cement composition. PMID:24801700

  7. Fluorescence background subtraction technique for hybrid fluorescence molecular tomography/x-ray computed tomography imaging of a mouse model of early stage lung cancer

    NASA Astrophysics Data System (ADS)

    Ale, Angelique; Ermolayev, Vladimir; Deliolanis, Nikolaos C.; Ntziachristos, Vasilis

    2013-05-01

    The ability to visualize early stage lung cancer is important in the study of biomarkers and targeting agents that could lead to earlier diagnosis. The recent development of hybrid free-space 360-deg fluorescence molecular tomography (FMT) and x-ray computed tomography (XCT) imaging yields a superior optical imaging modality for three-dimensional small animal fluorescence imaging over stand-alone optical systems. Imaging accuracy was improved by using XCT information in the fluorescence reconstruction method. Despite this progress, the detection sensitivity of targeted fluorescence agents remains limited by nonspecific background accumulation of the fluorochrome employed, which complicates early detection of murine cancers. Therefore we examine whether x-ray CT information and bulk fluorescence detection can be combined to increase detection sensitivity. Correspondingly, we research the performance of a data-driven fluorescence background estimator employed for subtraction of background fluorescence from acquisition data. Using mice containing known fluorochromes ex vivo, we demonstrate the reduction of background signals from reconstructed images and sensitivity improvements. Finally, by applying the method to in vivo data from K-ras transgenic mice developing lung cancer, we find small tumors at an early stage compared with reconstructions performed using raw data. We conclude with the benefits of employing fluorescence subtraction in hybrid FMT-XCT for early detection studies.

  8. Investigation of Essential Element Distribution in the Equine Metacarpophalangeal Joint using a Synchrotron Radiation Micro X-Ray Fluorescence Technique

    SciTech Connect

    Kaabar, Wejdan; Gundogdu, O.; Attenburrow, D.; Bradley, D. A. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Tzaphlidou, M. [Laboratory of Medical Physics, Medical School, University of Ioannina, 45110 Ioannina (Greece); Janousch, M. [LUCIA, Paul Scherrer Institute, Villigen (Switzerland)

    2008-05-20

    In articular cartilage, Ca, P, K and S are among some of the well known co-factors of the metalloproteinases enzymatic family, the latter playing a pivotal role in the growth and degeneration of the collagenous bone-cartilage interface of articulating joints. Current study forms part of a larger investigation concerning the distribution of these and other key elements in such media. For the purpose of evaluating these low atomic number elements (Z{<=}20), use was made of the capabilities of the LUCIA Station, located at the synchrotron facility of the Paul Scherrer Institute (PSI). Using an incident radiation energy of 4.06 keV, a synchrotron radiation micro x-ray fluorescence (SR-{mu}XRF) technique was applied in examining the distribution of the essential elements Ca, P, K and S in the bone-cartilage interface of both healthy and diseased (osteoarthritic) areas of an equine metacarpophalangeal joint. The SR-{mu}XRF mappings and line profile patterns have revealed remarkable changes in both the pattern and absolute distributions of these elements, agreeing with the findings of others. The elemental presence shown in the individual area scans encompassing the lesion each reflect the visibly abraded outer surface of the cartilage and change in shape of the bone surface. One of the area scans for the bone-cartilage interface shows a marked change in both the pattern and absolute elemental presence for all three elements compared to that observed at two other scan sites. The observation of change in bone cartilage composition around the surface of the articulating joint is thought to be novel, the variation being almost certainly due to the differing weight-bearing role of the subchondral bone at each locati0008.

  9. Application of x-ray lasers to current and future experiments in atomic and molecular physics

    SciTech Connect

    Caldwell, C. Denise [Department of Physics, University of Central Florida, Orlando, FL 32816-2385 (United States)

    1995-05-01

    The use of intrinsically narrow-banded, intense x-ray lasers has the potential for a significant impact in atomic and molecular physics. As with any new technology, it is impossible to predict all the new information which may emerge as the technology develops. At least at the beginning it will be important for these lasers to have applicability to existing experimental methods, which can then exploit the new tool for experiments which are currently barely feasible with existing and planned sources of radiation in the high-energy regime. Examples of these are: resonant Auger decay, particularly of dilute species, studied with electron spectrometry; multi-photon processes involving the simultaneous utilization of two laser photons; and fragmentation experiments in which the high-energy photon is one of a pump-probe pair. Results from these experiments will go a long way to suggesting directions for future study.

  10. On Photospheric Fluorescence and the Nature of the 17.62 Angstrom Feature in Solar X-ray Spectra

    NASA Technical Reports Server (NTRS)

    Drake, Jeremy J.; Swartz, Douglas A.; Beiersdorfer, Peter; Brown, Greg; Kahn, S.

    1999-01-01

    The identification of the emission line feature at 17.62 Angstroms in solar x-ray spectra is re-examined. Using a Monte Carlo technique, we compute a realistic theoretical upper limit to the observed Fe L-alpha photospheric fluorescent line strength caused by irradiation from an overlying corona. These calculations demonstrate that the photospheric Fe L-alpha characteristic line is much too weak to account for the observed 17.62 Angstrom line flux. Instead, we identify this line with the configuration interaction 2s2p3p2P-2s2p6 2S transition in Fe XVIII seen in Electron Beam Ion Trap spectra and predicted in earlier theoretical work on the Fe XVIII x-ray spectrum.

  11. Synchrotron X-Ray Fluorescence Microscopy of Gallium in Bladder Tissue following Gallium Maltolate Administration during Urinary Tract Infection

    PubMed Central

    Sampieri, Francesca; Chirino, Manuel; Hamilton, Don L.; Blyth, Robert I. R.; Sham, Tsun-Kong; Dowling, Patricia M.; Thompson, Julie

    2013-01-01

    A mouse model of cystitis caused by uropathogenic Escherichia coli was used to study the distribution of gallium in bladder tissue following oral administration of gallium maltolate during urinary tract infection. The median concentration of gallium in homogenized bladder tissue from infected mice was 1.93 ?g/g after daily administration of gallium maltolate for 5 days. Synchrotron X-ray fluorescence imaging and X-ray absorption spectroscopy of bladder sections confirmed that gallium arrived at the transitional epithelium, a potential site of uropathogenic E. coli infection. Gallium and iron were similarly but not identically distributed in the tissues, suggesting that at least some distribution mechanisms are not common between the two elements. The results of this study indicate that gallium maltolate may be a suitable candidate for further development as a novel antimicrobial therapy for urinary tract infections caused by uropathogenic E. coli. PMID:23877680

  12. A hard x-ray scanning microprobe for fluorescence imaging and microdiffraction at the advanced photon source

    NASA Astrophysics Data System (ADS)

    Cai, Z.; Lai, B.; Yun, W.; Ilinski, P.; Legnini, D.; Maser, J.; Rodrigues, W.

    2000-05-01

    A hard x-ray scanning microprobe based on zone plate optics and undulator radiation, in the energy region from 6 to 20 keV, has reached a focal spot size (FWHM) of 0.15 ?m(v)×0.6 ?m(h), and a photon flux of 4×109photons/sec/0.01%BW. Using a slit 44 meters upstream to create a virtual source, a circular beam spot of 0.15 ?m in diameter can be obtained with a photon flux of one order of magnitude less. During fluorescence mapping of trace elements in a single human ovarian cell, the microprobe exhibited an imaging sensitivity for Pt (L? line) of 80 attograms/?m2 for a count rate of 10 counts per second. The x-ray microprobe has been used to map crystallographic strain and multiquantum well thickness in micro-optoelectronic devices produced with the selective area growth technique.

  13. Investigation of molecular mechanisms of action of chelating drugs on protein-lipid model membranes by X-ray fluorescence

    SciTech Connect

    Novikova, N. N., E-mail: nn_novikova@ns.crys.ras.ru [Kurchatov Institute, Russian Research Center (Russian Federation); Zheludeva, S. I.; Koval'chuk, M. V.; Stepina, N. D. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Erko, A. I. [Berlin Electron Storage Ring Company for Synchrotron Radiation (Germany); Yur'eva, E. A. [Ministry of Health of the Russian Federation, Moscow Research Institute of Pediatrics and Pediatric Surgery (Russian Federation)

    2009-12-15

    Protein-lipid films based on the enzyme alkaline phosphatase were subjected to the action of chelating drugs, which are used for accelerating the removal of heavy metals from the human body, and the elemental composition of the resulting films was investigated. Total-reflection X-ray fluorescence measurements were performed at the Berlin Electron Storage Ring Company for Synchrotron Radiation (BESSY) in Germany. A comparative estimation of the protective effect of four drugs (EDTA, succimer, xydiphone, and mediphon) on membrane-bound enzymes damaged by lead ions was made. The changes in the elemental composition of the protein-lipid films caused by high doses of chelating drugs were investigated. It was shown that state-of-the-art X-ray techniques can, in principle, be used to develop new methods for the in vitro evaluation of the efficiency of drugs, providing differential data on their actions.

  14. Combination of grazing incidence x-ray fluorescence with x-ray reflectivity in one table-top spectrometer for improved characterization of thin layer and implants on/in silicon wafers

    NASA Astrophysics Data System (ADS)

    Ingerle, D.; Schiebl, M.; Streli, C.; Wobrauschek, P.

    2014-08-01

    As Grazing Incidence X-ray Fluorescence (GIXRF) analysis does not provide unambiguous results for the characterization of nanometre layers as well as nanometre depth profiles of implants in silicon wafers by its own, the approach of providing additional information using the signal from X-ray Reflectivity (XRR) was tested. As GIXRF already uses an X-ray beam impinging under grazing incidence and the variation of the angle of incidence, a GIXRF spectrometer was adapted with an XRR unit to obtain data from the angle dependent fluorescence radiation as well as data from the reflected beam. A ?-2? goniometer was simulated by combining a translation and tilt movement of a Silicon Drift detector, which allows detecting the reflected beam over 5 orders of magnitude. HfO2 layers as well as As implants in Silicon wafers in the nanometre range were characterized using this new setup. A just recently published combined evaluation approach was used for data evaluation.

  15. Limits of detection of a total reflection X-ray fluorescence system with double reflection module.

    PubMed

    Nascimento Filho, V F; Poblete, V H; Parreira, P S; Matsumoto, E; Simabuco, S M; Espinoza, E P; Navarro, A A

    1999-01-01

    An X-ray tube with a Mo target and Zr filter, operated at 45 kV/20 mA, was used to excite samples (5 microL deposited on a quartz support) and the total reflection angle condition was obtained with a double reflector module built with two 10-cm-long 7-mm-thick quartz crystals placed 50 microns apart. A high-resolution spectrometer based on a Si(Li) detector coupled to a multichannel analyzer was used for X-ray detection and the spectra were interpreted with the AXIL software. The system was calibrated with standard chemical solutions containing Cr, Fe, Cu, Zn, and Pb, and Y was used as an internal standard to correct eventual geometric errors and high-voltage instabilities of the X-ray generator. The limits of detection were 19, 9, 5, and 4 ng/mL for Cr, Fe, Cu, and Zn, respectively, analyzed through characteristic K alpha X-rays, and 7 ng/mL for Pb, through L alpha X-rays, considering 50 microL samples deposited and dried on a quartz support, to be excited/detected for 1000 s. PMID:10676518

  16. Quantification and localization of trace metals in natural plancton using a synchrotron x-ray fluorescence microprobe.

    SciTech Connect

    Twining, B. S.; Baines, S. B.; Fisher, N. S.; Jacobsen, C.; Maser, J.; State Univ. of New York at Stony Brook

    2003-03-01

    The accumulation of trace metals by planktonic protists influences the growth of primary producers, metal biogeochemical cycling, and metal bioaccumulation in aquatic food chains. Despite their importance, unequivocal measurements of trace element concentrations in individual plankton cells have not been possible to date. We have used the 2-ID-E side-branch hard x-ray microprobe at the Advanced Photon Source to measure trace elements in individual marine plankton cells. This microprobe employs zoneplate optics to produce the sub-micron spatial resolution and low background fluorescence required to produce trace element maps of planktonic protist cells ranging in size from 3 to >50 {micro}m. We have developed preservation, rinsing, and mounting protocols that remove most of the salt from our marine samples, thus simplifying the identification of unknown cells and reducing high Cl-related background fluorescence. We have also developed spectral modeling techniques that account for the frequent overlap of adjacent fluorescence peaks and non-uniform detector response. Finally, we have used parallel soft x-ray transmission and epifluorescence microscopy images to estimate C normalized trace element concentrations, identify functional cell types (e.g., photosynthetic vs. non-photosynthetic), and correlate cell structures with spatial patterns in trace element fluorescence.

  17. Characterization of urban air pollution by total reflection X-ray fluorescence*1

    NASA Astrophysics Data System (ADS)

    Schmeling, Martina

    2004-08-01

    Besides photochemical smog, particulate air pollution is a constantly growing problem in urban areas. The particulate matter present in pollution events contains often toxic or health impacting elements and is responsible for low visibility, might be triggering respiratory diseases like asthma, and can play an important role in formation or duration of smog events. To characterize particulate pollution in two different cities, samples were taken during intensive field campaigns in Chicago, IL, in 2002 and Phoenix, AZ, in 2001. Both cities experience regularly photochemical smog events as well as particulate pollution, but show very different meteorological and topographical conditions. Therefore it is expected that the particulate composition varies significantly, providing information about different pollution forms. Sampling took place in both cases at elevated locations and had a temporal resolution of 1.5 h and 1 h, respectively. The samples were analyzed by total reflection X-ray fluorescence after digestion of the filter matrix. As expected the elemental composition of particulate matter varied between both cities substantially with Phoenix showing a higher abundance of crustal elements, and Chicago enrichment in anthropogenically produced ones. In both cities diurnal patterns were found, exerting maxima in the morning and minima in the early afternoon. The diurnal pattern was much more regularly and also more strongly pronounced in Phoenix. Phoenix's valley location permits for a more stable nocturnal boundary layer to build up during the night thus trapping particulates efficiently during this time, until mixing occurs in the early morning hours and the residual layer lifts. In Chicago, the diurnal variation was less extreme, but another pattern determines the situation with the lake breeze. The lake breeze corresponds to a shift in wind direction towards the east, i.e. from Lake Michigan during the late morning. It was found that certain elemental species were enriched during a lake breeze event whereas this was not the case during other days. In conclusion, the low sample mass needed for TXRF analysis and the corresponding short sampling times, permitted the observation and characterization of local meteorological patterns in Phoenix and in Chicago.

  18. Evaluation of the uncertainties associated with in vivo X-ray fluorescence bone lead calibrations

    NASA Astrophysics Data System (ADS)

    Lodwick, Jeffrey C.

    An anthropometric leg phantom developed at the University of Cincinnati (UC) was used to evaluate the effects that changes in leg position and variation between subjects has on in vivo x-ray fluorescence (XRF) measurements of stable lead in bone. The changes in leg position that were evaluated include changes in source-phantom distance ranging between 0.0 mm and 30.0 mm and phantom rotation over 40 degrees. Source-phantom distance was determined to have a significant effect on XRF measurement results particularly at source-phantom distances greater than 10.0 mm. Rotation of the leg phantom through 40 degrees was determined to have no significant effect on XRF measurement results. Between subject factors that were evaluated include bone calcium content and overlying tissue thickness. Bone calcium content was determined to have a significant effect on XRF measurements when measuring lead in micrograms per gram bone material. However, if measurement results of micrograms of lead per gram calcium (or per gram bone mineral) is used the normalization method makes the change in calcium content not significant. Overlying tissue thickness was determined to have no significant effect on XRF measurement results with tissue thickness ranging between 5.7 and 11.62 mm. The UC leg phantom was modified to include a fibula bone phantom so that the effect that the fibula has on XRF measurement results could be evaluated. The fibula was determined to have no significant effect on XRF measurement results and in the future need not be incorporated into in vivo XRF calibration phantoms. A knee phantom was also developed for purposes of calibrations of in vivo XRF measurement of lead in the patella. XRF measurement results using this phantom were compared to results of XRF measurements made using the plaster-of-Paris (POP) phantoms. A significant difference was observed between the normalized count rates of the two phantom types when either micrograms of lead per gram of bone material or micrograms of lead per gram calcium (bone mineral) is used as the lead content. This difference is consistent with what is observed in real in vivo XRF measurements and indicates the need for the correction factors that are used.

  19. Identifying Objects via Encased X-Ray-Fluorescent Materials - the Bar Code Inside

    NASA Technical Reports Server (NTRS)

    Schramm, Harry F.; Kaiser, Bruce

    2005-01-01

    Systems for identifying objects by means of x-ray fluorescence (XRF) of encased labeling elements have been developed. The XRF spectra of objects so labeled would be analogous to the external bar code labels now used to track objects in everyday commerce. In conjunction with computer-based tracking systems, databases, and labeling conventions, the XRF labels could be used in essentially the same manner as that of bar codes to track inventories and to record and process commercial transactions. In addition, as summarized briefly below, embedded XRF labels could be used to verify the authenticity of products, thereby helping to deter counterfeiting and fraud. A system, as described above, is called an encased core product identification and authentication system (ECPIAS). The ECPIAS concept is a modified version of that of a related recently initiated commercial development of handheld XRF spectral scanners that would identify alloys or detect labeling elements deposited on the surfaces of objects. In contrast, an ECPIAS would utilize labeling elements encased within the objects of interest. The basic ECPIAS concept is best illustrated by means of an example of one of several potential applications: labeling of cultured pearls by labeling the seed particles implanted in oysters to grow the pearls. Each pearl farmer would be assigned a unique mixture of labeling elements that could be distinguished from the corresponding mixtures of other farmers. The mixture would be either incorporated into or applied to the surfaces of the seed prior to implantation in the oyster. If necessary, the labeled seed would be further coated to make it nontoxic to the oyster. After implantation, the growth of layers of mother of pearl on the seed would encase the XRF labels, making these labels integral, permanent parts of the pearls that could not be removed without destroying the pearls themselves. The XRF labels would be read by use of XRF scanners, the spectral data outputs of which would be converted to alphanumeric data in a digital equivalent data system (DEDS), which is the subject of the previous article. These alphanumeric data would be used to track the pearls through all stages of commerce, from the farmer to the retail customer.

  20. Modeling of atomic processes for x-ray-laser plasmas. Final report, 15 June 1986-14 February 1988

    SciTech Connect

    Gupta, U.

    1988-07-01

    This work dealt with the theoretical modeling and computation of photoionization, photoexcitation, radiative decay, and radiative recombination processes for multielectron atoms and ions in plasmas. Such atomic processes lead to and influence lasing in x-ray lasers operating both in the soft- and hard-x-ray regions. This research utilized a two-component, finite temperature, self consistent density functional method and demonstrated that this method is applicable for arbitrary plasma density and temperature and is capable of accurately treating multielectron ions of arbitrary Z. Electron-collisional ionization and excitation processes were investigated. These processes are an important mechanism through which population inversion of ionic energy levels lead to lasing in the soft x-ray region. Previously, theoretical calculations utilizing a semi-classical impact approximation were performed. In many cases such a method is inadequate. Computations were carried out by electron-impact ionization and excitation cross sections and rate coefficients utilizing the distorted wave with exchange method.

  1. The study of chemical composition and elemental mappings of colored over-glaze porcelain fired in Qing Dynasty by micro-X-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Lin, Cheng; Meitian, Li; Youshi, Kim; Changsheng, Fan; Shanghai, Wang; Qiuli, Pan; Zhiguo, Liu; Rongwu, Li

    2011-02-01

    It is very difficult to measure the chemical composition of colored pigments of over-glaze porcelain by X-ray fluorescence because it contains high concentration of Pb. One of the disadvantages of our polycapillary optics is that it has low transmission efficiency to the high energy X-ray. However, it is beneficial to measure the chemical compositions of rich Pb sample. In this paper, we reported the performances of a tabletop setup of micro-X-ray fluorescence system base on slightly focusing polycapillary and its applications for analysis of rich Pb sample. A piece of Chinese ancient over-glaze porcelain was analyzed by micro-X-ray fluorescence. The experimental results showed that the Cu, Fe and Mn are the major color elements. The possibilities of the process of decorative technology were discussed in this paper, also.

  2. POLYMER FILM STANDARDS FOR X-RAY FLUORESCENCE SPECTROMETERS (JOURNAL VERSION)

    EPA Science Inventory

    Sets of thin polymer films were developed to serve as standards for XRF analysis of the following 18 elements in aerosol particle samples: Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, As, Rb, Sr, Zr, Cd, Sb, Ba, and Pb. Each film contains a pair of elements having non-interfering x-ray...

  3. Iodine vapor staining for atomic number contrast in backscattered electron and X-ray imaging.

    PubMed

    Boyde, Alan; Mccorkell, Fergus A; Taylor, Graham K; Bomphrey, Richard J; Doube, Michael

    2014-12-01

    Iodine imparts strong contrast to objects imaged with electrons and X-rays due to its high atomic number (53), and is widely used in liquid form as a microscopic stain and clinical contrast agent. We have developed a simple technique which exploits elemental iodine's sublimation-deposition state-change equilibrium to vapor stain specimens with iodine gas. Specimens are enclosed in a gas-tight container along with a small mass of solid I2 . The bottle is left at ambient laboratory conditions while staining proceeds until empirically determined completion (typically days to weeks). We demonstrate the utility of iodine vapor staining by applying it to resin-embedded tissue blocks and whole locusts and imaging them with backscattered electron scanning electron microscopy (BSE SEM) or X-ray microtomography (XMT). Contrast is comparable to that achieved with liquid staining but without the consequent tissue shrinkage, stain pooling, or uneven coverage artefacts associated with immersing the specimen in iodine solutions. Unmineralized tissue histology can be read in BSE SEM images with good discrimination between tissue components. Organs within the locust head are readily distinguished in XMT images with particularly useful contrast in the chitin exoskeleton, muscle and nerves. Here, we have used iodine vapor staining for two imaging modalities in frequent use in our laboratories and on the specimen types with which we work. It is likely to be equally convenient for a wide range of specimens, and for other modalities which generate contrast from electron- and photon-sample interactions, such as transmission electron microscopy and light microscopy. PMID:25219801

  4. A portable micro-X-ray fluorescence spectrometer with polycapillary optics and vacuum chamber for archaeometric and other applications

    NASA Astrophysics Data System (ADS)

    Buzanich, G.; Wobrauschek, P.; Streli, C.; Markowicz, A.; Wegrzynek, D.; Chinea-Cano, E.; Bamford, S.

    2007-11-01

    A portable focused-beam XRF spectrometer was designed, constructed, and manufactured. The spectrometer allows to detect and perform analysis of chemical elements from Na upwards. The system is equipped with a compact vacuum chamber to reduce absorption of both the excitation and the fluorescence radiation in air. A low power Pd-anode tube operated up to 50 kV and 1 mA with a point focus of 400 ?m is used as excitation source. A polycapillary lens with a spot size of about 160 ?m, or a collimator with a 1 mm inner diameter can be used alternatively for either focusing or collimating the primary beam. The fluorescence radiation is collected by an Si drift detector with an active area of 10 mm 2 and equipped with an 8 ?m Be entrance window. A compact vacuum chamber was designed to house the X-ray beam optics and the detector snout. The chamber is attached to the X-ray tube and can be pumped down to 0.1 mbar. A Kapton™ window of 7.5 ?m thickness allows to locate the investigated spot at about 1-2 mm distance outside of the chamber, thus minimizing absorption losses in the excitation and X-ray fluorescence radiation paths. Two lasers pointers are mounted inside the chamber. The laser beams cross at a point outside the chamber in front of the entrance window and coincide with the focal spot of the polycapillary. This paper reports some preliminary results obtained from an in situ analysis of bronze samples as well as a comparison of these data with those given by other laboratory spectrometers and the reference values provided by the Italian bronze foundry Venturi Arte Bologna, Italy.

  5. Imaging performance of a hybrid x-ray computed tomography-fluorescence molecular tomography system using priors

    SciTech Connect

    Ale, Angelique; Schulz, Ralf B.; Sarantopoulos, Athanasios; Ntziachristos, Vasilis [Institute for Biological and Medical Imaging, Technische Universitaet Muenchen and Helmholtz Zentrum Muenchen, Ingolstaedter Landstrasse 1, D-85764 Neuherberg (Germany)

    2010-05-15

    Purpose: The performance is studied of two newly introduced and previously suggested methods that incorporate priors into inversion schemes associated with data from a recently developed hybrid x-ray computed tomography and fluorescence molecular tomography system, the latter based on CCD camera photon detection. The unique data set studied attains accurately registered data of high spatially sampled photon fields propagating through tissue along 360 deg. projections. Methods: Approaches that incorporate structural prior information were included in the inverse problem by adding a penalty term to the minimization function utilized for image reconstructions. Results were compared as to their performance with simulated and experimental data from a lung inflammation animal model and against the inversions achieved when not using priors. Results: The importance of using priors over stand-alone inversions is also showcased with high spatial sampling simulated and experimental data. The approach of optimal performance in resolving fluorescent biodistribution in small animals is also discussed. Conclusions: Inclusion of prior information from x-ray CT data in the reconstruction of the fluorescence biodistribution leads to improved agreement between the reconstruction and validation images for both simulated and experimental data.

  6. Pigments Elementary Chemical Composition Study of a Gainsborough Attributed Painting Employing a Portable X-Rays Fluorescence System

    NASA Astrophysics Data System (ADS)

    Appoloni, C. R.; Blonski, M. S.; Parreira, P. S.; Souza, L. A. C.

    2007-02-01

    The investigated painting, identified with the title "The woodman", is attributed to Thomas Gainsborough (XVIII century) and is under investigation at the Laboratory of Conservation Science (LACICOR), CECOR/EBA/UFMG. The measurements were carried out with a portable X-rays fluorescence (XRF) system constituted of a X-rays tube with Ag anode, a Si PIN — diode detector, nuclear electronic chain and a special designed mechanical system for the detector and X-ray tube positioning, that enables angular and XYZ movements of the excitation-detection system. The employed voltage and current intensity were 17 kV and 3 mA, respectively. The time of acquisition for each measurement was 500 s. XRF spectra were analyzed using the AXIL-WinQXAS software. Three measurements in each of the following regions of the painting were done: face, leaves, arm, sky and firewood. The carried out analysis indicated the following pigments: White (lead white and calcium sulfate, identified by the elements Pb, Ca and S), Blue (Prussian blue, identified by the key element Fe), Red (Vermilion, identified by the elements Hg and S) and Brown (mixture of Fe and Mn oxides, identified by the elements Fe and Mn). Elements belonging to modern pigments corresponding to the same colors were absent in the analyzed spectra.

  7. Pots, plates and provenance: sourcing Indian coarse wares from Mleiha using X-ray fluorescence (XRF) spectrometry analysis

    NASA Astrophysics Data System (ADS)

    Reddy, A.; Attaelmanan, A. G.; Mouton, M.

    2012-07-01

    The identification of more than 25% of the pottery sherds from the late PIR.D period (ca. 2nd - mid. 3rd c. AD) assemblage from the recently excavated building H at Mleiha as Indian is based on form and fabric, but using only visual assessment. Petrographic analysis of the fabrics can provide more precise indicators of the geographical origin of the wares. In this study, a total of 21 sherds from various key sites in Western India were compared with 7 different 'Indian' coarse-ware vessels sampled at Mleiha using X-ray fluorescence (XRF) spectrometry. The analyses were conducted on powdered samples collected from the core of each sherd. Each sample was irradiated for 1000 seconds using a 1.2 mm diameter X-ray beam. The resulting spectra were used for quantification of the X-ray intensity and elemental concentration. Levels of correlation in the elemental ratios of the sherds were statistically tested using an F-test as well as a Chi-test. Initial review of the XRF results indicates that the Maharashtra and Gujarat regions of India are probable source areas for at least two of the types of wares. Collection of additional samples from these areas and other regions of India, and further statistical analysis through methods such as Principal Component Analysis will help to isolate groups of wares from India and correlate them with types of vessels imported into the Oman peninsula in antiquity.

  8. A high-quality multilayer structure characterization method based on X-ray fluorescence and Monte Carlo simulation

    NASA Astrophysics Data System (ADS)

    Brunetti, Antonio; Golosio, Bruno; Melis, Maria Grazia; Mura, Stefania

    2015-02-01

    X-ray fluorescence (XRF) is a well known nondestructive technique. It is also applied to multilayer characterization, due to its possibility of estimating both composition and thickness of the layers. Several kinds of cultural heritage samples can be considered as a complex multilayer, such as paintings or decorated objects or some types of metallic samples. Furthermore, they often have rough surfaces and this makes a precise determination of the structure and composition harder. The standard quantitative XRF approach does not take into account this aspect. In this paper, we propose a novel approach based on a combined use of X-ray measurements performed with a polychromatic beam and Monte Carlo simulations. All the information contained in an X-ray spectrum is used. This approach allows obtaining a very good estimation of the sample contents both in terms of chemical elements and material thickness, and in this sense, represents an improvement of the possibility of XRF measurements. Some examples will be examined and discussed.

  9. Radioisotope X-ray fluorescence and neutron activation analyses of the trace element concentrations of the rainbow trout

    NASA Astrophysics Data System (ADS)

    Akyuz, T.; Bassari, A.; Bolcal, C.; Sener, E.; Yildiz, M.; Kucer, R.; Kaplan, Z.; Dogan, G.; Akyuz, S.

    1999-01-01

    The muscles and livers of the ten rainbow trouts ( Oncorhynchus mykiss; N, 1752) obtained from Sapanca, Aquaculture Facility of Aquatic Products Faculty, The University of Istanbul (Turkey), have been analysed quantitatively for some minor elements using the radioisotope energy dispersive X-ray fluorescence (EDXRF) and neutron activation analysis (NAA) methods. It was found that samples contain Na, K, Ca, Sc, Cs, Fe, Co, Cu, Zn, Se, Br, Rb, Sr, Au, La and Ce in different amounts. Comparison of the results with those of reference river fish samples indicated that agricultural rainbow trout samples from Sapanca region have higher Fe level.

  10. Determination of heavy metals in biofilms from the River Elbe by total-reflection X-ray fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Friese, K.; Mages, M.; Wendt-Potthoff, K.; Neu, T. R.

    1997-07-01

    Heavy metal contents of aquatic biofilms isolated from stones collected from, and ceramic plates exposed in, the River Elbe were determined by total-reflection X-ray fluorescence spectrometry (TXRF). The fractions of several elements (K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Pb) referred to the dry mass are 100 to 60?000-fold higher in the biofilm matrix compared with the bulk water phase. Biofilms grown on the exposed plates have a mass fraction of the determined elements higher by a factor of 2-3 compared with the biofilms derived from stones. These differences may be attributed to the different ages of the biofilms.

  11. In situ multi-element analyses by energy-dispersive X-ray fluorescence on varnishes of historical violins

    NASA Astrophysics Data System (ADS)

    Echard, Jean-Philippe

    2004-10-01

    Varnishes of Italian violins and other historical stringed instruments have been analyzed by energy-dispersive X-ray fluorescence (EDXRF). The instruments whose varnishes were to be analyzed were chosen from the collection kept in Musée de la Musique in Paris. Direct analyses were performed on instrument varnishes, without any sampling and non-destructively, showing inorganic elements such as lead, mercury and iron that could be related to siccatives or pigments. Analytical results and their comparison with old formulae or traditional recipes of violin varnishes, as with the few previous analytical results, will be discussed.

  12. Study of the correlation between the coal calorific value and coal ash content using X-ray fluorescence analysis

    NASA Astrophysics Data System (ADS)

    Bolortuya, D.; Zuzaan, P.; Gustova, M. V.; Maslov, O. D.

    2013-12-01

    In this paper we have studied the possibility of determining the chemical elements in coal samples using X-ray fluorescence analysis and have found a relationship between the coal calorific value and its ash content with the coal moisture accounting. The amount of coal ash can be determined by the content of the basic chemical elements, such as Si, Sr, Fe, and Ca. It was concluded that the calorific value of coal can be estimated from the ash content in coal without the calorimetric measurements. These correlation coefficients were calculated for coal from several coal mines in Mongolia. The results are in good agreement with the results of chemical analysis.

  13. In-situ stoichiometry determination using x-ray fluorescence generated by reflection-high-energy-electron-diffraction

    SciTech Connect

    Keenan, Cameron; Chandril, Sandeep; Lederman, David [Department of Physics and Multifunctional Materials Laboratory, West Virginia University, Morgantown, West Virginia 26506 (United States); Myers, T. H. [Department of Physics and Multifunctional Materials Laboratory, West Virginia University, Morgantown, West Virginia 26506 (United States); Materials Science, Engineering, and Commercialization Program, Texas State University-San Marcos, San Marcos, Texas 78666 (United States)

    2011-06-01

    A major challenge in the stoichiometric growth of complex oxide compounds is the control of the relative compositions of the constituent materials. A potential avenue for compositional analysis during growth is the use of x-ray fluorescence generated during reflection high energy electron diffraction measurements. Using this technique, relative compositions of Y and Mn in molecular beam epitaxy grown YMnO{sub 3} samples were studied. Comparing the results with Rutherford back scattering spectroscopy suggests that the technique has the potential for real-time analysis of elemental fluxes and stoichiometry control during sample growth.

  14. Examination of trafficking of phagocytosed colloid particles in neutrophils using synchrotron-based X-ray fluorescence microscopy (XFM)

    Microsoft Academic Search

    Stuart C. Ramsay; Nathan Cassidy; Martin D. de Jonge; Daryl L. Howard; David Paterson; Natkunam Ketheesan

    Synchrotron-based X-ray fluorescence microscopy (XFM) can localise chemical elements at a subcellular level. 99mTechnetium\\u000a stannous (TcSn) colloid is taken up by phagocytes via a Complement Receptor 3 mediated phagocytic process. In the current\\u000a study, XFM was used to examine the intracellular trafficking of TcSn colloid in neutrophils. XFM was performed on TcSn colloid,\\u000a and neutrophils labelled with TcSn colloid, in

  15. Metal allergy in dentistry: detection of allergen metals with X-ray fluorescence spectroscope and its application toward allergen elimination.

    PubMed

    Suzuki, N

    1995-01-01

    Numerous metal allergies possibly resulting from intraoral metal restorations have been reported, although the mechanism of onset is not yet completely understood. Allergen elimination may be the most effective treatment, and location of allergen metal becomes essential. The x-ray fluorescence spectroscope was used to detect the allergen metals in intraoral metal restorations and personal and household items of metal allergy patients. The apparatus was evaluated preceding its clinical application, and restorations and personal items for 381 patients were analyzed to detect allergens. Successful diagnoses and allergen elimination treatment of three patients are reported. PMID:7575978

  16. The application of trend surface analysis to a portion of the Apollo 15 X-ray fluorescence data

    NASA Technical Reports Server (NTRS)

    Podwysocki, M. H.; Weidner, J. R.; Andre, C. G.; Bickel, A. L.; Lum, R. S.; Adler, I.; Trombka, J. I.

    1974-01-01

    X-ray fluorescence data for 8 and 16 second time integrals gathered by Apollo 15 in circum lunar orbit were analyzed to determine the capability for chemical mapping of relatively small lunar features in a portion of Tranquillitatis and Serenitatis basins. Spatial mapping using trend surface analysis demonstrated that a useable signal could be extracted from Al/Si intensity ratios calculated for 8 second time spans. Reliability of the Al/Si ratio was enhanced when 16 second data were compiled using a sliding average technique. Residual anomalies from the trend surface mapping were identified and correlated with relatively small lunar surface features.

  17. Elemental concentrations in skin of patients with fibroeptelial polip using synchrotron radiation total reflection x-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Soares, Júlio C. A. C. R.; Anjos, Marcelino J.; Canellas, Catarine G. L.; Lopes, Ricardo T.

    2012-05-01

    In this work, the concentrations of trace elements were measured in acrochordon, a skin lesion also known as skin tag or fibroepithelial polyp, as well as in normal skin from the same patient. The samples were analyzed by Synchrotron Radiation Total Reflection X-ray Fluorescence (SRTXRF) in the Synchrotron Light National Laboratory (LNLS) in Campinas/São Paulo-Brazil. The collection of lesion and healthy skin samples, including papillary dermis and epidermis, has involved 17 patients. It was evaluated the presence of P, S, Cl, K, Ca, Fe, Cu and Zn in the paired samples, which were compared, and significant differences were found in some of them.

  18. High Energy Resolution Fluorescence Detection X-Ray Absorption Spectroscopy: Detection of Adsorption Sites in Supported Metal Catalysts

    SciTech Connect

    Tromp, Moniek [University of Southampton, School of Chemistry, Highfield, Southampton, SO17 1BJ (United Kingdom); Bokhoven, Jeroen A. van [Institute for chemical and bioengineering ETH Zurich (Switzerland); Safonova, Olga V.; Glatzel, Pieter [ESRF, Grenoble (France); Groot, Frank M. F. de [Utrecht University, Utrecht (Netherlands); Evans, John [University of Southampton, School of Chemistry, Highfield, Southampton, SO17 1BJ (United Kingdom); Diamond Light Source, Didcot (United Kingdom)

    2007-02-02

    High energy resolution fluorescence detection (HERFD) X-ray adsorption spectroscopy (XAS) is demonstrated as a new tool to identify the geometry of metal adsorption sites and the orbitals involved in bonding. The type of CO adsorption site on a nanoparticular Pt-Al2O3 catalyst is determined. The orbitals involved in the Pt - CO bonding are identified using theoretical FEFF8.0 calculations. In situ application of HERFD XAS is applicable to a large number of catalytic systems and will provide fundamental insights in structure - performance relationships.

  19. Atomic data for astrophysics: Fe xii soft X-ray lines

    NASA Astrophysics Data System (ADS)

    Del Zanna, G.; Storey, P. J.; Badnell, N. R.; Mason, H. E.

    2012-07-01

    We present new large-scale R-matrix (up to n = 4) and distorted-wave (DW, up to n = 6) scattering calculations for electron collisional excitation of Fe xii. The first aim is to provide accurate atomic data for the soft X-rays, where strong decays from the n = 4 levels are present. As found in previous work on Fe x, resonances attached to n = 4 levels increase the cross-sections for excitations from the ground state to some n = 4 levels, when compared to DW calculations. Cascading from higher levels is also important. We provide a number of models and line intensities, and list a number of strong unidentified lines. The second aim is to assess the effects of the large R-matrix calculation on the n = 3 transitions. Compared to our previous (n = 3) R-matrix calculation, we find overall excellent agreement to within a few percent, however a few key density diagnostic EUV intensities differ by about 60% at coronal densities. The new atomic data result in lower electron densities, resolving previous discrepancies with solar observations. The full dataset (energies, transition probabilities and rates) are available in electronic form at our APAP website (http://www.apap-network.org) as well as at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/543/A139

  20. Comprehensive X-ray Absorption Models for Atomic Oxygen and Neon

    NASA Astrophysics Data System (ADS)

    Gorczyca, Thomas; Garcia, Javier; Bautista, Manuel; Mendoza, Claudio; Gatuzz, Efrain; Kallman, Timothy R.

    2014-06-01

    An analytical formula is developed to represent accurately the photoabsorption cross sections of oxygen and neon for all energies of interest for X-ray spectral modeling purposes. In the vicinity of the K-edge, a Rydberg series expression is used to fit R-matrix results, including important orbital relaxation effects, which accurately predict the absorption oscillator strengths below threshold and merge consistently and continuously to the above-threshold cross section. Further minor adjustments are made to the threshold energies in order to align the atomic Rydberg resonances most reliably after consideration of both experimental and observed line positions. At energies far below or above the K-edge region, the formulation is based on both outer-shell and inner-shell direct photoionization, including significant shake-up and shake-off processes that result in photoionization-excitation and double photoionization contributions to the total cross section. The ultimate purpose for developing a definitive model for oxygen absorption is to resolve a discrepancy between the inferred atomic and molecular oxygen abundances in the interstellar medium (ISM) from XSTAR and SPEX spectral models.

  1. Hydrodynamic, Atomic Kinetic, and Monte Carlo Radiation Transfer Models of the X-ray Spectra of Compact Binaries

    SciTech Connect

    Mauche, C W; Liedahl, D A; Akiyama, S; Plewa, T

    2008-02-08

    We describe the results of an effort, funded by the Lawrence Livermore National Laboratory Directed Research and Development Program, to model, using FLASH time-dependent adaptive-mesh hydrodynamic simulations, XSTAR photoionization calculations, HULLAC atomic data, and Monte Carlo radiation transport, the radiatively-driven photoionized wind and accretion flow of high-mass X-ray binaries (HMXBs). In this final report, we describe the purpose, approach, and technical accomplishments of this effort, including maps of the density, temperature, velocity, ionization parameter, and emissivity distributions of the X-ray emission lines of the well-studied HMXB Vela X-1.

  2. Synchrotron radiation total reflection X-ray fluorescence and energy dispersive X-ray fluorescence analysis on AP1™ films applied to the analysis of trace elements in metal alloys for the construction of nuclear reactor core components: a comparison

    NASA Astrophysics Data System (ADS)

    Pepponi, G.; Wobrauschek, P.; Hegedüs, F.; Streli, C.; Zöger, N.; Jokubonis, C.; Falkenberg, G.; Grimmer, H.

    2001-11-01

    Synchrotron radiation induced total reflection X-ray fluorescence and conventional 45° energy dispersive X-ray fluorescence analysis using a 150-nm-thick AP1™ film as sample carrier have been exploited for the elemental analysis of traces in alloys used for the construction of reactor core components of nuclear power plants. Both techniques are well suited for the analysis since they require a low amount of sample (?l), important on one hand because of the limited disposal and on the other hand because of its high specific activity. The methods provide a very low background due to the total reflection phenomenon in TXRF and the thin AP1™ film sample support, respectively. The employment of synchrotron radiation was necessary since there are no laboratory sources which can deliver a collimated beam of the energy and intensity needed to excite the K-shell of the rare earth elements, allowing the achievement of minimum detection limits relevant for the proposed purpose (ng/g range). Moreover, the linear polarization of synchrotron radiation combined with a side-looking detection geometry manages to reduce the scattering due to the remaining matrix of the analyzed samples. Detection limits for Nb and for some of the rare earth elements (pg range for absolute detection limits and ng-?g/g range for concentration detection limits) obtained with the two techniques are presented and the two approaches are compared.

  3. A new spectrometer for grazing incidence X-ray fluorescence for the characterization of Arsenic implants and Hf based high-k layers

    NASA Astrophysics Data System (ADS)

    Ingerle, D.; Meirer, F.; Zoeger, N.; Pepponi, G.; Giubertoni, D.; Steinhauser, G.; Wobrauschek, P.; Streli, C.

    2010-06-01

    Grazing Incidence X-ray Fluorescence Analysis (GIXRF) is a powerful technique for depth-profiling and characterization of thin layers in depths up to a few hundred nanometers. By measurement of fluorescence signals at various incidence angles Grazing Incidence X-ray Fluorescence Analysis provides information on depth distribution and total dose of the elements in the layers. The technique is very sensitive even in depths of a few nanometers. As Grazing Incidence X-ray Fluorescence Analysis does not provide unambigous depth profile information and needs a realistic input depth profile for fitting, in the context of the EC funded European Integrated Activity of Excellence and Networking for Nano and Micro-Electronics Analysis (ANNA) Grazing Incidence X-ray Fluorescence Analysis is used as a complementary technique to Secondary Ion Mass Spectrometry (SIMS) for the characterization of Ultra Shallow Junctions (USJ). A measuring chamber was designed, constructed and tested to meet the requirements of Grazing Incidence X-ray Fluorescence Analysis. A measurement protocol was developed and tested. Some results for As implants as well as Hf based high k layers on Silicon are shown. For the determination of the bulk As content of the wafers, Instrumental Neutron Activation Analysis has also been applied for comparison.

  4. A Green Fluorescent Protein Containing a QFG Tri-Peptide Chromophore: Optical Properties and X-Ray Crystal Structure

    PubMed Central

    Byres, Emma; Rossjohn, Jamie; Devenish, Rodney J.; Olsen, Seth; Wilce, Matthew C. J.; Prescott, Mark

    2012-01-01

    Rtms5 is an deep blue weakly fluorescent GFP-like protein (, 592 nm; , 630nm; ?F, 0.004) that contains a 66Gln-Tyr-Gly chromophore tripeptide sequence. We investigated the optical properties and structure of two variants, Rtms5Y67F and Rtms5Y67F/H146S in which the tyrosine at position 67 was substituted by a phenylalanine. Compared to the parent proteins the optical spectra for these new variants were significantly blue-shifted. Rtms5Y67F spectra were characterised by two absorbing species (, 440 nm and 513 nm) and green fluorescence emission (, 440 nm; , 508 nm; ?F, 0.11), whilst Rtms5Y67F/H146S spectra were characterised by a single absorbing species (, 440 nm) and a relatively high fluorescence quantum yield (?F, 0.75; , 440 nm; , 508 nm). The fluorescence emissions of each variant were remarkably stable over a wide range of pH (3–11). These are the first GFP-like proteins with green emissions (500–520 nm) that do not have a tyrosine at position 67. The X-ray crystal structure of each protein was determined to 2.2 Å resolution and showed that the benzylidine ring of the chromophore, similar to the 4-hydroxybenzylidine ring of the Rtms5 parent, is non-coplanar and in the trans conformation. The results of chemical quantum calculations together with the structural data suggested that the 513 nm absorbing species in Rtms5Y67F results from an unusual form of the chromophore protonated at the acylimine oxygen. These are the first X-ray crystal structures for fluorescent proteins with a functional chromophore containing a phenylalanine at position 67. PMID:23071789

  5. Scanning X-ray fluorescent elemental microanalysis with synchrotron radiation in geochemical research

    NASA Astrophysics Data System (ADS)

    Darin, A.; Kalugin, I.; Zolotarev, K.

    2009-04-01

    The traditional XRF analysis with high limits of detection is limited in application for geochemical researches. Use of synchrotron radiation considerably expands its opportunities [1]. Since 1985 in BINP analytical works with syncrotron radiation from storage ring VEPP-3 are carried out. A plenty of methodical and research works with geochemical samples has been executed. The range of energy excitation 15 - 50 keV is now accessible, that allows to determine the following elements in geological samples weight from 1 mg: P, S, Cl, K, Ca, Ti (LD=50 ppm, St.dev.=5 ppm); V, Cr, Mn, Fe, Co, Ni (LD=5 ppm, St.dev.=0.5 ppm); Cu, Zn, Ga, Ge, As, Se (LD=0.5 ppm, St.dev.=0.05 ppm); Br, Rb, Sr, Y, Zr, Nb, Mo (LD=0.1 ppm, St.dev.=0.03 ppm); Ru, Rh, Pd, Ag (LD=0.05 ppm, St.dev.=0.01 ppm); Cd, In, Sn, Sb, Te, I (LD=0.1 ppm, St.dev.=0.03 ppm); Ba, La, Ce, Nd, Sm (LD=1.0 ppm, St.dev.=0.15 ppm); Pb, Bi, Th, U (LD=1 ppm, St.dev.=0.1 ppm). The analysis is carried out in some stages with use various energy of excitation (usually - 15-18, 22 - 25 and 40-45 keV). The first instrument of scanning X-ray fluorescent elemental microanalysis with synchrotron radiation from storage ring VEPP-3 (scan.XRFA-SR) was founded in BINP SB RAS in the 1988 and applied to study the spatial distribution of elements in geological samples [2]. Scan.XRFA-SR was used in paleoclimate reconstructions based on high-resolution sediments and tree-rings analysis [3, 4, 5]. Unique opportunities of XRF SR allow to carry out scanning microanalysis with spatial resolution ~ 10 micron. The set of analyzed elements and range of concentration are determined by selection of energy of excitation and time of measurement in a point. In recent years, has been studied many different geological samples: diamonds, xenolith, ferromanganese nodules, bottom sediments. Studies have demonstrated the unique ability of scanning XRFA-SR: a simultaneous analysis of more than 30 chemical elements with a spatial resolution of 10-50 microns. [1] V. B. Baryshev et all. Rev. Sci. Instrum. 60 (1989) N7 2456. [2] A. V. Daryin et all. Nucl. Instrum. and Meth. A308 (1991) 318. [3] K.V. Zolotarev et all. Nucl. Instrum. and Meth. A470 (2001),376. [4] A.V. Daryin et all. Nucl. Instrum. and Meth. A 543 (2005) 255. [5] I.A. Kalugin et all. Quaternary Research 67 (2007) 400.

  6. Laboratory Tests of a Handheld X-Ray Fluorescence Spectrometer: A Tool for Planetary Exploration

    NASA Astrophysics Data System (ADS)

    Young, K. E.; Evans, C. A.; Hodges, K.

    2011-12-01

    Maximizing the science return from a mission to another planetary surface involves the integration of science objectives with deployable technologies that enable the collection of data and samples. For long duration manned missions, it is likely that more samples will be collected than can be returned to Earth due to mass limits. A niche exists for technologies that help prioritize samples for return, provide data for future sample handling and curation, and characterization for samples that are not returned to Earth. To fill this niche, hardware and protocols for field instruments are currently being developed and evaluated at NASA Johnson Space Center and Arizona State University. Our goal is to develop an easily used, environmentally isolated facility as part of the astronaut surface habitat for preliminary sample characterization and down-selection. NASA has constructed a prototype, GeoLab, as a testbed for evaluating the scientific applicability and operational considerations of various analytical instruments. One instrument under evaluation is a small, portable x-ray fluorescence (XRF) spectrometer that can be also be used by astronaut explorers as part of their field gear while on scientific sorties, or on robotic field assistants. We report on preliminary usability tests for commercially available handheld XRF instruments. These instruments collect data by contacting the surface of a rock or sediment sample with an 8 mm-wide sensor window. Within 60 seconds, the devices can provide relatively precise data on the abundance of major and trace elements heavier than Na. Lab-based handheld XRF analyses of terrestrial and lunar samples, compared with those made with full-scale laboratory XRF systems, show good correlation, but we continue to investigate potential sources of error and the need for careful calibration with standards of known composition. Specifically, we use a suite of five terrestrial and five lunar basalts, all well characterized by conventional XRF technology, to evaluate the handheld technology. All of these samples are fine-grained and homogeneous, and were selected to eliminate effects introduced to the data by inconsistencies in the sample matrix, or added complexities like increased vesicularity or phenocryst content. Our calibration curves are built from smooth, sawed surfaces. We have examined all major elements, minus Na (which falls below the instrument sensitivity). Initial tests show that reproducible and reliable calibration curves are produced for Ca, Fe, Al, Ti, and Si, but the curves produced for Mg, Mn, K and P include greater uncertainties. We are currently investigating how the instrument signal variably drops off as a function of surface roughness and distance to the instrument window. Through studies such as these in the simulated GeoLab setting, we can better understand the instrument's capabilities in a field environment, both on Earth and for potential future missions to other planetary surfaces.

  7. [The study of selecting sample detecting position and lead plate inner material in thin film method X-ray fluorescence measurement].

    PubMed

    Gan, Ting-ting; Zhang, Yu-jun; Zhao, Nan-jing; Yin, Gao-fang; Dong, Xin-xin; Wang, Ya-ping; Liu Jian-guo; Liu, Wen-qing

    2015-01-01

    (1) In this paper type 316 stainless steel metal plate as the research object, the selection of sample detecting position was studied when thin film method X-ray fluorescence measurement was conducted. The study showed that the optimal location for the sample detection was sample distance X-ray tube and detector baseline 1cm with the baseline into a 16°angle. (2) Heavy metal pollutants of Pb, Cd and Cr in industrial ambient air as the main analysis object, when thin film method X-ray fluorescence conducted with lead plate protection, X-rays will penetrate the membrane and continuely stimulate the protective lead plate. Therefore there is lead spectral line interference in the filter membrane background spectrum, which will affect the detection of lead element in real samples. Studies show that when a layer of isolating material was applied between the thin sample and the protective lead plate, the interference of lead line can effectively be avoided. (3) Several rigid insulating material of type 316 stainless steel, brass, aluminum, red copper and PTEE as lead inner material were selected and studied. The study results showed that compared with X-ray fluorescence spectra of other lead inner materials, the X-ray fluorescence spectrum of red copper contained the least element spectral lines. There were not Cr, Cd and Pb spectrum peaks in the X-ray fluorescence spectrum of red copper. And the target timber scattering spectrum intensity in the high energy part was weaker compared to other X-ray fluorescence spectrum. The above analysis shows that red copper has the minimal disturbance to the actual measurement of heavy metals Cr, Cd and Pb. At the same time, red copper as lead inner materials can effectively avoid the interference of lead spectrum line in lead plate. So red copper is the best lead plate inner materials in thin film method X-ray fluorescence spectroscopy measurement. This study provides an important theoretical basis for the assembling and setting'up air and water weight metal X-ray fluorescence spectrometer. PMID:25993859

  8. X-ray transfer

    SciTech Connect

    Castor, J.I.

    1992-03-01

    The computational techniques for treating radiative transfer in general, and x-ray transfer in particular, are reviewed, with emphasis on the difficult problems associated with systems that are not in local thermodynamic equilibrium. Some special aspects of x-ray transfer are mentioned. The computer code ALTAIR, developed at LLNL to solve such problems, is described briefly, with an example of x-ray fluorescence in a Seyfert galaxy. Some of the prospects for experimental tests of x-ray radiative transfer theory are considered.

  9. Atomic Number and Electron Density Measurement Using a Conventional X-ray Tube and a CdTe Detector

    NASA Astrophysics Data System (ADS)

    Zou, Wenjuan; Nakashima, Takuya; Onishi, Yoshiaki; Koike, Akifumi; Shinomiya, Bunji; Morii, Hisashi; Neo, Yoichiro; Mimura, Hidenori; Aoki, Toru

    2008-09-01

    In order to apply the dual-energy technique to material identification, a new computed tomography scanning system was proposed using a conventional X-ray tube and a CdTe detector. This system can provide information of projection data at two distinct energy bands for scanned materials. After introducing an approximation, the measured projection data were reconstructed to obtain the distributions of the X-ray linear attenuation coefficients of the materials at two different energies. Then, the corresponding atomic number and electron density can be derived with the dual-energy X-ray computed tomography (DXCT) method adopted. By comparing the obtained results with theoretical ones, the feasibility of using this system for identifying low-Z materials was demonstrated in this study.

  10. Pseudopotential calculations of photoionization of atoms in the x-ray photon energy range and FEL beam monitor development

    NASA Astrophysics Data System (ADS)

    Chernov, V. E.; Dorofeev, D. L.; Elfimov, S. V.; Zon, B. A.; Gavrilov, G. E.; Naryshkin, Yu G.

    2015-03-01

    A pseudopotential model for calculation of atomic processes under interaction with hard x-ray photons is applied to calculation of Krypton photoionization cross sections by photons with energy in the 20–25 keV range. These cross sections, as well as the mean charge of the resulting ions calculated using the Monte Carlo simulation scheme, are in good agreement with the other theoretical calculations and with the experiment. The obtained results open the doors for new techniques in the design of gas-monitor detectors to control the intensity, coordinates and energy of x-ray free-electron laser (XFEL) beams in the hard x-ray photon energy range. First, Monte Carlo simulations of a scintillation detector application for gas-monitors have been performed.

  11. Present trends and future perspectives for atomic and molecular physics at the new X-ray light sources

    Microsoft Academic Search

    M. N. Piancastelli; M. Simon; K. Ueda

    2010-01-01

    The major advances in the actual and predicted performances of new light sources (low-emittance storage rings and soft and hard X-ray free-electron lasers) in the last few years have provided a new impulse to the development of atomic and molecular physics, in particular in what concerns electronic structure and dynamics of atoms, molecules, liquids and clusters investigated with photoelectron spectroscopy,

  12. Calibration of the lunar orbital x-ray fluorescence imaging spectrometer (LOXIA) of Chang'E-1 satellite at INAF-OAPA

    NASA Astrophysics Data System (ADS)

    Barbera, Marco; Candia, Roberto; Collura, Alfonso; Di Cicca, Gaspare; Varisco, Salvatore; Zhang, Chengmo; Wang, Huan Yu; Yang, JiaWei; Peng, Wenxi; Cui, Xingzhu; Cao, XueLei; Liang, XiaoHua

    2007-09-01

    The Lunar Orbital X-ray Fluorescence Imaging Spectrometer (LOXIA) designed and constructed at the Institute of High Energy Physics of the Chinese Academy of Sciences to perform chemical composition analysis of the Moon surface will operate on-board the Chang'E-1 mission, the first Chinese lunar spacecraft to be launched in 2007. We report the main results of the calibration measurements that we have performed using the X-ray beamline of the XACT facility of INAFOsservatorio Astronomico di Palermo G.S. Vaiana to determine the quantum efficiency of the XRS detector in the soft X-rays as a function of photon energy and angle of incidence.

  13. Non-destructive trace element microanalysis of as-received cometary nucleus samples using synchrotron x ray fluorescence

    NASA Technical Reports Server (NTRS)

    Sutton, S. R.

    1989-01-01

    The Synchrotron X ray Fluorescence (SXRF) microprobe at the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory, will be an excellent instrument for non-destructive trace element analyses of cometary nucleus samples. Trace element analyses of as-received cometary nucleus material will also be possible with this technique. Bulk analysis of relatively volatile elements will be important in establishing comet formation conditions. However, as demonstrated for meteorites, microanalyses of individual phases in their petrographic context are crucial in defining the histories of particular components in unequilibrated specimens. Perhaps most informative in comparing cometary material with meteorites will be the halogens and trace metals. In-situ, high spatial resolution microanalyses will be essential in establishing host phases for these elements and identifying terrestrial (collection/processing) overprints. The present SXRF microprobe is a simple, yet powerful, instrument in which specimens are excited with filtered, continuum synchrotron radiation from a bending magnet on a 2.5 GeV electron storage ring. A refrigerated cell will be constructed to permit analyses at low temperatures. The cell will consist essentially of an air tight housing with a cold stage. Kapton windows will be used to allow the incident synchrotron beam to enter the cell and fluorescent x rays to exit it. The cell will be either under vacuum or continuous purge by ultrapure helium during analyses. Several other improvements of the NSLS microprobe will be made prior to the cometary nucleus sample return mission that will greatly enhance the sensitivity of the technique.

  14. Ion beam sputtering techniques for high-resolution concentration depth profiling with glancing-incidence X-ray fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Wiener, G.; Günther, R.; Michaelsen, C.; Knoth, J.; Schwenke, H.; Bormann, R.

    1997-07-01

    The application of ion beam sputtering in combination with glancing-incidence X-ray fluorescence spectrometry for high-resolution concentration depth profiling is presented. Two new techniques are described: first, in the "bevel-etching technique", the sample depth profile is uncovered on the sample surface either by sputter etching with a gradient of the ion beam intensity or by varying the sputtering time by moving a shutter in front of the sample; second, in the "deposition technique", samples are etched uniformly and the sputtered material is deposited on a moving substrate. The bevelled sample and also the material deposited on the substrate are characterized (laterally resolved) by glancing incidence X-ray fluorescence spectrometry. The apparatus and techniques are described in detail. Typical experiments showing the advantages of and problems with the two techniques are discussed. The achievable depth resolutions, 1.5 nm with the bevel-etching technique and 1.4 nm with the deposition technique, are comparable with the best results from other depth profiling methods.

  15. FMT-PCCT: hybrid fluorescence molecular tomography-x-ray phase-contrast CT imaging of mouse models.

    PubMed

    Mohajerani, Pouyan; Hipp, Alexander; Willner, Marian; Marschner, Mathias; Trajkovic-Arsic, Marija; Ma, Xiaopeng; Burton, Neal C; Klemm, Uwe; Radrich, Karin; Ermolayev, Vladimir; Tzoumas, Stratis; Siveke, Jens T; Bech, Martin; Pfeiffer, Franz; Ntziachristos, Vasilis

    2014-07-01

    The implementation of hybrid fluorescence molecular tomography (FMT) and X-ray computed tomography (CT) has been shown to be a necessary development, not only for combining anatomical with functional and molecular contrast, but also for generating optical images of high accuracy. FMT affords highly sensitive 3-D imaging of fluorescence bio-distribution, but in stand-alone form it offers images of low resolution. It was shown that FMT accuracy significantly improves by considering anatomical priors from CT. Conversely, CT generally suffers from low soft tissue contrast. Therefore utilization of CT data as prior information in FMT inversion is challenging when different internal organs are not clearly differentiated. Instead, we combined herein FMT with emerging X-ray phase-contrast CT (PCCT). PCCT relies on phase shift differences in tissue to achieve soft tissue contrast superior to conventional CT. We demonstrate for the first time FMT-PCCT imaging of different animal models, where FMT and PCCT scans were performed in vivo and ex vivo, respectively. The results show that FMT-PCCT expands the potential of FMT in imaging lesions with otherwise low or no CT contrast, while retaining the cost benefits of CT and simplicity of hybrid device realizations. The results point to the most accurate FMT performance to date. PMID:24686244

  16. 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

  17. Folic acid-conjugated silica capped gold nanoclusters for targeted fluorescence/X-ray computed tomography imaging

    PubMed Central

    2013-01-01

    Background Gastric cancer is 2th most common cancer in China, and is still the second most common cause of cancer-related death in the world. Successful development of safe and effective nanoprobes for in vivo gastric cancer targeting imaging is a big challenge. This study is aimed to develop folic acid (FA)-conjugated silica coated gold nanoclusters (AuNCs) for targeted dual-modal fluorescent and X-ray computed tomography imaging (CT) of in vivo gastric cancer cells. Method AuNCs were prepared, silica was coated on the surface of AuNCs, then folic acid was covalently anchored on the surface of AuNCs, resultant FA-conjugated AuNCs@SiO2 nanoprobes were investigated their cytotoxicity by MTT method, and their targeted ability to FR(+) MGC803 cells and FR(?) GES-1 cells. Nude mice model loaded with MGC803 cells were prepared, prepared nanoprobes were injected into nude mice via tail vein, and then were imaged by fluorescent and X-ray computed tomography (CT) imaging. Results FA-conjugated AuNCs@SiO2 nanoprobes exhibited good biocompatibility, and could target actively the FR(+) MGC-803 cells and in vivo gastric cancer tissues with 5 mm in diameter in nude mice models, exhibited excellent red emitting fluorescence imaging and CT imaging. Conclusion The high-performance FA-conjugated AuNCs@SiO2 nanoprobes can target in vivo gastric cancer cells, can be used for fluorescent and CT dual-mode imaging, and may own great potential in applications such as targeted dual-mode imaging of in vivo early gastric cancer and other tumors with FR positive expression in near future. PMID:23718865

  18. Ultrabright multikilovolt x-ray source: saturated amplification on noble gas transition arrays from hollow atom states

    DOEpatents

    Rhodes, Charles K.; Boyer, Keith

    2004-02-17

    An apparatus and method for the generation of ultrabright multikilovolt x-rays from saturated amplification on noble gas transition arrays from hollow atom states is described. Conditions for x-ray amplification in this spectral region combine the production of cold, high-Z matter, with the direct, selective multiphoton excitation of hollow atoms from clusters using ultraviolet radiation and a nonlinear mode of confined, self-channeled propagation in plasmas. Data obtained is consistent with the presence of saturated amplification on several transition arrays of the hollow atom Xe(L) spectrum (.lambda..about.2.9 .ANG.). An estimate of the peak brightness achieved is .about.10.sup.29 .gamma..multidot.s.sup.-1.multidot.mm.sup.-2.multidot.mr.sup.-2 (0.1% Bandwidth).sup.-1, that is .about.10.sup.5 -fold higher than presently available synchotron technology.

  19. Direct determination of trace elements in boron nitride powders by slurry sampling total reflection X-ray fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Amberger, Martin A.; Höltig, Michael; Broekaert, José A. C.

    2010-02-01

    The use of slurry sampling total reflection X-ray fluorescence spectrometry (SlS-TXRF) for the direct determination of Ca, Cr, Cu, Fe, Mn and Ti in four boron nitride powders has been described. Measurements of the zeta potential showed that slurries with good stabilities can be obtained by the addition of polyethylenimine (PEI) at a concentration of 0.1 wt.% and by adjusting the pH at 4. For the optimization of the concentration of boron nitride in the slurries the net line intensities and the signal to background ratios were determined for the trace elements Ca and Ti as well as for the internal standard element Ga in the case of concentrations of boron nitride ranging from 1 to 30 mg mL -1. As a compromise with respect to high net line intensities and high signal to background ratios, concentrations of 5 mg mL -1 of boron nitride were found suitable and were used for all further measurements. The limits of detection of SlS-TXRF for the boron nitride powders were found to range from 0.062 to 1.6 ?g g - 1 for Cu and Ca, respectively. Herewith, they are higher than those obtained in solid sampling and slurry sampling graphite furnace atomic absorption spectrometry (SoS-GFAAS, SlS-GFAAS) as well as those of solid sampling electrothermal evaporation inductively coupled plasma optical emission spectrometry (SoS-ETV-ICP-OES). For Ca and Fe as well as for Cu and Fe, however, they were found to be lower than for GFAAS and for ICP-OES subsequent to wet chemical digestion, respectively. The universal applicability of SlS-TXRF to the analysis of samples with a wide variety of matrices could be demonstrated by the analysis of certified reference materials such as SiC, Al 2O 3, powdered bovine liver and borate ore with a single calibration. The correlation coefficients of the plots for the values found for Ca, Fe and Ti by SlS-TXRF in the boron nitride powders as well as in the before mentioned samples versus the reference values for the respective samples over a concentration range from 2.5 to 1470 ?g g - 1 were found to be 0.995, 0.991 and 0.997, respectively.

  20. Dynamical Diffraction and X-Ray Standing Waves from Atomic Planes Normal to a Twofold Symmetry Axis of the Quasicrystal AlPdMn

    SciTech Connect

    Jach, T. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)] [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Zhang, Y.; Colella, R. [Department of Physics, Purdue University, West Lafayette, Indiana 47907 (United States)] [Department of Physics, Purdue University, West Lafayette, Indiana 47907 (United States); de Boissieu, M.; Boudard, M. [LTPCM-ENSEEG, BP 75, 38402 St. Martin d`Heres Cedex (France)] [LTPCM-ENSEEG, BP 75, 38402 St. Martin d`Heres Cedex (France); Goldman, A.I.; Lograsso, T.A.; Delaney, D.W. [Department of Physics and Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States)] [Department of Physics and Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States); Kycia, S. [CHESS, Cornell University, Ithaca, New York 14853 (United States)] [CHESS, Cornell University, Ithaca, New York 14853 (United States)

    1999-04-01

    We have observed dynamical diffraction in the 0240{ovr 2}4 and 0460{ovr 4}6 reflections of the icosahedral quasicrystal AlPdMn in the back-reflection geometry ({theta}{sub B}=90{degree} ). The x-ray fluorescence from the Al and Pd atoms exhibits strong standing wave behavior, similar to that observed in crystalline materials. The data indicate a long-range order of each species of atoms, with the coherent positions attributable to distributions of the Al and Pd, which we compare to a centrosymmetric model. We observe deviations from the model which imply small departures from inversion symmetry along the twofold symmetry axis and from the expected coherent fractions for Al. {copyright} {ital 1999} {ital The American Physical Society}