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1

Monte Carlo simulation of x-ray fluorescence and scattering tomography experiments  

Microsoft Academic Search

Experimental data and results from a detailed Monte Carlo (MC) simulation of X-ray Fluorescence, Compton and Rayleigh scattering tomography are presented. The MC model was developed by the authors for aiding the optimization and evaluation of synchrotron radiation induced X-ray fluorescence (SRXRF) experiments. The code simulates complete X-ray fluorescence spectra in the incident energy range of 1 - 100 keV,

Laszlo Vincze; Koen Janssens; B. Vekemans; F. Adams

1999-01-01

2

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

Microsoft Academic Search

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

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

2010-01-01

3

Monte Carlo simulation of x-ray fluorescence and scattering tomography experiments  

NASA Astrophysics Data System (ADS)

Experimental data and results from a detailed Monte Carlo (MC) simulation of X-ray Fluorescence, Compton and Rayleigh scattering tomography are presented. The MC model was developed by the authors for aiding the optimization and evaluation of synchrotron radiation induced X-ray fluorescence (SRXRF) experiments. The code simulates complete X-ray fluorescence spectra in the incident energy range of 1 - 100 keV, including K,L fluorescent lines and Compton, Rayleigh scattering contributions. This generalized simulation model describes the interactions between X-ray photons and heterogenous samples. The MC code was evaluated by comparisons of simulated and experimental X-ray fluorescent and scattering tomography data. These data were collected at HASYLAB, beamline L (polychromatic setup) and BW5 (monochromatic setup). Good agreement was found between experimental and simulated results.

Vincze, Laszlo; Janssens, Koen; Vekemans, B.; Adams, F.

1999-09-01

4

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

Microsoft Academic Search

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

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

2011-01-01

5

Quantitative analysis results of CE-1 X-ray fluorescence spectrometer ground base experiment  

NASA Astrophysics Data System (ADS)

As the nearest celestial body to the earth, the moon has become a hot spot again in astronomy field recently. The element analysis is a much important subject in many lunar projects. Remote X-ray spectrometry plays an important role in the geochemical exploration of the solar bodies. Because of the quasi-vacuum atmosphere on the moon, which has no absorption of X-ray, the X-ray fluorescence analysis is an effective way to determine the elemental abundance of lunar surface. The CE-1 X-ray fluorescence spectrometer (CE-1/XFS) aims to map the major elemental compositions on the lunar surface. This paper describes a method for quantitative analysis of elemental compositions. A series of ground base experiments are done to examine the capability of XFS. The obtained results, which show a reasonable agreement with the certified values at a 30% uncertainty level for major elements, are presented.

Cui, Xing-Zhu; Wang, Huan-Yu; Zhang, Cheng-Mo; Chen, Yong; Zhang, Jia-Yu; Peng, Wen-Xi; Cao, Xue-Lei; Liang, Xiao-Hua; Wang, Jin-Zhou; Gao, Min; Yang, Jia-Wei

2008-01-01

6

Apollo 16 Geochemical X-ray Fluorescence Experiment: Preliminary Report.  

PubMed

The lunar surface was mapped with respect to magnesium, aluminum, and silicon as aluminum/ silicon and magnesium/ silicon intensity ratios along the projected ground tracks swept out by the orbiting Apollo 16 spacecraft. The results confirm the observations made during the Apollo 15 flight and provide new data for a number of features not covered before. The data are consistent with the idea that the moon has a widespread differentiated crust (the highlands). The aluminum/ silicon and magnesium/ silicon concentration ratios correspond to those for anorthositic gabbros through gabbroic anorthosites or feldspathic basalts. The x-ray results suggest the occurrence of this premare crust or material similar to it at the Descartes landing site. PMID:17815621

Adler, I; Trombka, J; Gerard, J; Lowman, P; Schmadebeck, R; Blodget, H; Eller, E; Yin, L; Lamothe, R; Osswald, G; Gorenstein, P; Bjorkholm, P; Gursky, H; Harris, B

1972-07-21

7

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

NASA Astrophysics Data System (ADS)

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 knowledge of the X-ray spectrometer efficiency, but also of the spectrometer response functions makes it possible to define a physical spectral background of XRF spectra. Background subtraction relying on purely mathematical procedures is state-of-the-art. The results produced by the analytical model are at least as reliable as those obtained by Monte-Carlo simulations, even without considering the very challenging contribution of multiple scattering. Special attention has been paid to Compton broadening. Relevant applications of the implementation of the analytical model presented in this paper are the prediction of the limits of detection for particular cases or the determination of the transmission of X-ray polycapillary lenses.

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

2010-12-01

8

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)

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 BAMline/BESSY II. Monte-Carlo simulations have been also carried out in order to evaluate the quality of the results achieved with the model.

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

2011-07-01

9

X-ray fluorescence microscopy  

SciTech Connect

Synchrotron x-ray fluorescence microscopy is used to quantitatively measure and image the distribution of trace elements in biological, geological and materials science specimens. The design and performance of the x-ray fluorescence (XFR) microprobe at the NSLS are discussed and compared with other XRF microprobe design. An example of a trace element image obtained with this instrument if presented. 6 refs., 5 figs.

Rivers, M.L.; Sutton, S.R. (Chicago Univ., IL (USA). Dept. of Geophysical Sciences); Jones, K.W. (Brookhaven National Lab., Upton, NY (USA))

1990-10-01

10

Geometrical factor correction in grazing incident x-ray fluorescence experiment.  

PubMed

The geometrical factor in the grazing incident x-ray fluorescence analysis is an important angle-dependent term, which can have a great effect on the measured data. In this paper, the effects of the geometrical factor on the florescence yield have been demonstrated. A formula is presented to estimate the geometrical factor, which includes the experimental parameters of the beam and setup. The validity of this formula is proven by the good agreement between the calculated fluorescence yields with the experimental results in grazing incident x-ray fluorescence analysis. PMID:22667609

Li, Wenbin; Zhu, Jingtao; Ma, Xiaoying; Li, Haochuan; Wang, Hongchang; Sawhney, Kawal J S; Wang, Zhanshan

2012-05-01

11

Geometrical factor correction in grazing incident x-ray fluorescence experiment  

SciTech Connect

The geometrical factor in the grazing incident x-ray fluorescence analysis is an important angle-dependent term, which can have a great effect on the measured data. In this paper, the effects of the geometrical factor on the florescence yield have been demonstrated. A formula is presented to estimate the geometrical factor, which includes the experimental parameters of the beam and setup. The validity of this formula is proven by the good agreement between the calculated fluorescence yields with the experimental results in grazing incident x-ray fluorescence analysis.

Li Wenbin; Zhu Jingtao; Ma Xiaoying; Li Haochuan; Wang Hongchang; Wang Zhanshan [Key Laboratory of Advanced Micro-Structured Materials, MOE, Institute of Precision Optical Engineering, Department of Physics, Tongji University, Shanghai 200092 (China); Sawhney, Kawal J. S. [Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom)

2012-05-15

12

NEW CORRECTION PROCEDURE FOR X-RAY SPECTROSCOPIC FLUORESCENCE DATA: SIMULATIONS AND EXPERIMENT.  

SciTech Connect

X-ray fluorescence spectroscopy is a widely used method for determining the electronic configuration and local structure of dilute species with high sensitivity. In the dilute limit, and for thin films, the X-ray fluorescence signal is directly proportional to the atomic sub-shell absorption coefficient. However, for concentrated samples, the well-documented self-absorption effect often leads to the severe suppression of XANES (X-ray Absorption Near-Edge Structure) and EXAFS (Extended X-ray Absorption Fine-Structure) amplitudes. Thus to recover the real value of the sub-shell absorption coefficient, it is important to apply correction procedures to the measured fluorescence spectra. In this paper, we describe a new straightforward method to correct for self-absorption effects (the difference in the measured fluorescence signal compared to that of the true sub-shell photoabsorption coefficient) in XANES and EXAFS fluorescence measurements. Using a variety of sample and detector configurations, this method is used to extract the sub-shell absorption coefficient on elemental nickel and thick single-crystals of Gd{sub 3}Ga{sub 5}O{sub 12} and LaAlO{sub 3}.

ABLETT, J.M.; WOICIK, J.C.; KAO, C.C.

2004-08-02

13

X-ray fluorescence holography  

NASA Astrophysics Data System (ADS)

X-ray fluorescence holography (XFH) is a method of atomic resolution holography which utilizes fluorescing atoms as a wave source or a monitor of the interference field within a crystal sample. It provides three-dimensional atomic images around a specified element and has a range of up to a few nm in real space. Because of this feature, XFH is expected to be used for medium-range local structural analysis, which cannot be performed by x-ray diffraction or x-ray absorption fine structure analysis. In this article, we explain the theory of XFH including solutions to the twin-image problem, an advanced measuring system, and data processing for the reconstruction of atomic images. Then, we briefly introduce our recent applications of this technique to the analysis of local lattice distortions in mixed crystals and nanometer-size clusters appearing in the low-temperature phase of a shape-memory alloy.

Hayashi, Kouichi; Happo, Naohisa; Hosokawa, Shinya; Hu, Wen; Matsushita, Tomohiro

2012-03-01

14

Chemical Environment Effects on K[beta]/K[alpha] Intensity Ratio: An X-Ray Fluorescence Experiment on Periodic Trends  

ERIC Educational Resources Information Center

|X-ray fluorescence (XRF) data from an energy-dispersive XRF instrument were used to investigate the chlorine K[alpha] and K[beta] peaks in several group 1 salts. The ratio of the peak intensity is sensitive to the local chemical environment of the chlorine atoms studied in this experiment and it shows a periodic trend for these salts. (Contains 1…

Durham, Chaney R.; Chase, Jeffery M.; Nivens, Delana A.; Baird, William H.; Padgett, Clifford W.

2011-01-01

15

Measurements of K x-ray fluorescence parameters  

Microsoft Academic Search

A simple x-ray fluorescence experiment suitable for graduate and undergraduate laboratories is described. The experiment uses a NaI(Tl) x-ray spectrometer, a weak 57Co radioactive source (~105 Bq), and medium-Z targets of silver, cadmium, indium, and tin. The K x-ray fluorescence yield, omegak, and K x-ray production cross section, sigmak, are measured for these targets. Accurate results are achieved by adopting

A. S. Bennal; P. D. Shidling; N. M. Badiger; S. R. Thontadarya; B. Hanumaiah

2005-01-01

16

Wavelength dispersive X-ray fluorescence imaging.  

PubMed

A new wavelength-dispersive X-ray fluorescence (WD-XRF) imaging spectrometer equipped with a two-dimensional X-ray detector was developed in the laboratory. Straight polycapillary optics was applied instead of a soller slit, which is used in conventional WD-XRF spectrometers. X-rays were guided through the straight polycapillary to the exit of the optics by X-ray external total reflections. X-ray fluorescence was dispersed by an analyzing crystal (LiF(200)), keeping the information of elemental distribution on the surface of the sample. The energy resolution of the developed spectrometer was 130-152 eV at the Zn K? peak. X-ray elemental images of Cu K? and Ni K? were successfully obtained by an X-ray CCD detector at the corresponding diffraction angles. The analytical performance of this technique, and further improvements are discussed. PMID:21749148

Tsuji, Kouichi; Ohmori, Takashi; Yamaguchi, Makoto

2011-07-27

17

X-ray microprobe for micro x-ray fluorescence and absorption spectroscopies at GSECARS  

Microsoft Academic Search

The hard x-ray microprobe for x-ray fluorescence and absorption spectroscopy at GeoSoilEnviroCARS is presented. Using focused synchrotron radiation from an undulator beamline at the Advanced Photon Source at Argonne National Lab, the x-ray microprobe provides bright, monochromatic x-rays with typical spot sizes down to 1x1 mum for x-ray fluorescence and absorption spectroscopies. Quantitative x-ray fluorescence (XRF) analysis gives precise elemental

M. Newville; S. Sutton; M. Rivers

2002-01-01

18

X-Ray Fluorescent Recovers Ancient Text  

NSDL National Science Digital Library

This article from Cornell University News Service presents an interdisciplinary effort among physicists and classicists to read a weathered 2000-year-old inscription on stone with x-ray fluorescence. The article describes how a powerful x-ray light source at Cornell produced fluorescence in trace elements in the inscribed stone and includes images showing the original inscription. The article is written for the general public.

2008-10-27

19

Planetary X-ray fluorescence analogue laboratory experiments and an elemental abundance algorithm for C1XS  

NASA Astrophysics Data System (ADS)

We have conducted laboratory experiments as an analogue to planetary XRF (X-ray fluorescence) missions in order to investigate the role of changing incidence (and phase) angle geometry and sample grain-size on the intensity of XRF from regolith-like samples. Our data provide evidence of a grain-size effect, where XRF line intensity decreases with increasing sample grain-size, as well as an almost ubiquitous increase in XRF line intensity above incidence angles of ˜60°. Data from a lunar regolith simulant are also used to test the accuracy of an XRF abundance algorithm developed at the Rutherford Appleton Laboratory (RAL), which is used to estimate the major element abundance of the lunar surface from Chandrayaan-1 X-ray Spectrometer (C1XS) XRF data. In ideal situations (i.e., when the input spectrum is well defined and the XRF spectrum has a sufficient signal to noise ratio) the algorithm can recover a known rock composition to within 1.0 elemental wt% (1 ?).

Weider, Shoshana Z.; Swinyard, Bruce M.; Kellett, Barry J.; Howe, Chris J.; Joy, Katherine H.; Crawford, Ian A.; Gow, Jason; Smith, David R.

2011-10-01

20

X-ray fluorescence with synchrotron radiation  

SciTech Connect

X-ray fluorescence (XRF) has long been used to make measurements of trace element concentrations in biological materials with very high sensitivity. It has not been previously possible to work with micrometer spatial resolutions because of the relatively low brightness of x-ray tubes. This situation is much improved by using synchrotron storage ring x-ray sources since the brightness of the synchrotron source is many orders of magnitude higher than is obtained with the most intense tube sources. These intense sources open the possibility of using the XRF technique for measurements with resolutions of approximately cellular dimensions. A description of a current research project at Brookhaven which uses synchrotron radiation induced x-ray emission (SRIXE) is presented to illustrate a specific application of the method in biology. 1 ref., 4 figs.

Jones, K.W.; Gordon, B.M.; Hanson, A.L.; Pounds, J.G.; Schidlovsky, G.

1986-03-01

21

Synchrotron x-ray fluorescence and extended x-ray absorption fine structure analysis  

SciTech Connect

The advent of dedicated synchrotron radiation sources has led to a significant increase in activity in many areas of science dealing with the interaction of x-rays with matter. Synchrotron radiation provides intense, linearly polarized, naturally collimated, continuously tunable photon beams, which are used to determine not only the elemental composition of a complex, polyatomic, dilute material but also the chemical form of the elements with improved accuracy. Examples of the application of synchrotron radiation include experiments in synchrotron x-ray fluorescence (SXRF) analysis and extended x-ray absorption fine structure (EXAFS) analysis. New synchrotron radiation x-ray microprobes for elemental analysis in the parts per billion range are under construction at several laboratories. 76 references, 24 figures.

Chen, J.R.; Gordon, B.M.; Hanson, A.L.; Jones, K.W.; Kraner, H.W.; Chao, E.C.T.; Minkin, J.A.

1984-01-01

22

Method for X-ray fluorescence spectroscopy  

Microsoft Academic Search

A method and apparatus are described for performing X-ray fluorescence analysis where the physical relationship between the source\\/detector and the object being examined is not controlled. This technique and apparatus is particularly advantageous in performing an in situ analysis of the concentration of one or more elements present in a matrix of a material such as rock. In accordance with

W. C. Boyce; T. E. Hall; L. C. Howard; W. M. Lechelt; W. D. Wittekind

1985-01-01

23

Simulation of x-ray fluorescence spectra  

SciTech Connect

A method for simulating x-ray fluorescence (XRF) spectra in hybrid densitometry is presented. This technique allows simulation of XRF spectra for solutions with arbitrary concentrations of special nuclear material and minor actinides excited by an x-ray generator. Spectra for mixed uranium and plutonium solutions with U/Pu ratios ranging from 100 to 1 have been generated. This range of ratios applies to most solutions found in plutonium reprocessing plants. XRF simulation can provide important data for estimating instrument precision, evaluating analysis techniques, and training system operators. Applications of XRF simulation in the development of the Los Alamos Hybrid K-Edge/XRF Densitometer system are described.

Collins, M.L.; Hsue, S.T. [Los Alamos National Lab., NM (United States); Gunnink, R. [Gunnink (R.), Fremont, CA (United States)

1996-09-01

24

Monte Carlo simulation of X-ray fluorescence spectra: Part 4. Photon scattering at high X-ray energies  

Microsoft Academic Search

The photon scattering model of a Monte Carlo simulation code for synchrotron radiation X-ray fluorescence (SRXRF) spectrometers is evaluated at high X-ray energies (60–100 keV) by means of a series of validation experiments performed at Beamline BW5 of HASYLAB. Using monochromatic X-rays, Compton\\/Rayleigh multiple scattering experiments were performed on polypropylene, Al and Cu samples. Especially in the case of the

L. Vincze; K Janssens; B Vekemans; F Adams

1999-01-01

25

First X-ray fluorescence CT experimental results at the SSRF X-ray imaging beamline  

NASA Astrophysics Data System (ADS)

X-ray fluorescence CT is a non-destructive technique for detecting elemental composition and distribution inside a specimen. In this paper, the first experimental results of X-ray fluorescence CT obtained at the SSRF X-ray imaging beamline (BL13W1) are described. The test samples were investigated and the 2D elemental image was reconstructed using a filtered back-projection algorithm. In the sample the element Cd was observed. Up to now, the X-ray fluorescence CT could be carried out at the SSRF X-ray imaging beamline.

Deng, Biao; Yang, Qun; Xie, Hong-Lan; Du, Guo-Hao; Xiao, Ti-Qiao

2011-04-01

26

Development of X-Ray Polarimeter by Detecting Secondary Fluorescent X-Rays.  

National Technical Information Service (NTIS)

A new kind of X-ray polarimeter, which was successfully operated below 2 KeV X-ray, is described. The angular distribution of secondary fluorescent X-rays emitted in the process of photoelectric effect is expected to exhibit an asymmetry correlated with t...

T. Kifune

1972-01-01

27

Low Power X-Ray Tube for Use in Energy Dispersive X-Ray Fluorescence Analysis.  

National Technical Information Service (NTIS)

A low power X-ray tube with thin molybdenum transmission target for use in energy dispersive X-ray fluorescence (ENDXRF) element analysis has been indigenously built, along with its power supply. The X-ray tube has been in operation since August 1979, and...

S. K. Kataria R. Govil M. Lal

1980-01-01

28

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

Microsoft Academic Search

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

Richard Newman

1998-01-01

29

The USA X-ray timing experiment  

Microsoft Academic Search

The USA Experiment is a new X-ray timing experiment with large collecting area and microsecond time resolution capable of conducting a broad program of studies of galactic X-ray binaries. USA is one of nine experiments aboard the Advanced Research and Global Observation Satellite which was launched February 23, 1999. USA is a collimated proportional counter X-ray telescope with about 1000

P. S. Ray; K. S. Wood; G. Fritz; P. Hertz; M. Kowalski; W. N. Johnson; M. N. Lovellette; M. T. Wolff; D. Yentis; R. M. Bandyopadhyay; E. D. Bloom; B. Giebels; G. Godfrey; K. Reilly; P. Saz Parkinson; G. Shabad; P. Michelson; M. Roberts; D. A. Leahy; L. Cominsky; J. Scargle; J. Beall; D. Chakrabarty; Y. Kim

2001-01-01

30

The USA X-ray Timing Experiment  

Microsoft Academic Search

The USA Experiment is a new X-ray timing experiment with large collecting area and microsecond time resolution capable of conducting a broad program of studies of galactic X-ray binaries. USA is one of nine experiments aboard the Advanced Research and Global Observation Satellite which was launched February 23, 1999. USA is a collimated proportional counter X-ray telescope with about 1000

P. S. Ray; K. S. Wood; G. Fritz; P. Hertz; M. Kowalski; W. N. Johnson; M. N. Lovellette; M. T. Wolff; D. Yentis; R. M. Bandyopadhyay; E. D. Bloom; B. Giebels; G. Godfrey; K. Reilly; P. Saz Parkinson; G. Shabad; P. Michelson; M. Roberts; D. A. Leahy; L. Cominsky; J. Scargle; J. Beall; D. Chakrabarty; Y. Kim

1999-01-01

31

Introduction to Energy-Dispersive X-Ray Fluorescence Analysis.  

National Technical Information Service (NTIS)

The physical principles of energy dispersive x-ray fluorescence analysis are discussed. A phenomenological description of atomic excitation and the subsequent radiation of x rays on which the physical principles are built, is presented. The atomic shell s...

D. C. Camp

1978-01-01

32

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

SciTech Connect

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.

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

33

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

NASA Astrophysics Data System (ADS)

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.

Naeem, Syed F.; Chouffani, Khalid; Wells, Douglas P.

2009-03-01

34

Fundamental characteristics of hybrid X-ray focusing optics for micro X-ray fluorescence analysis  

NASA Astrophysics Data System (ADS)

We developed a hybrid X-ray focusing optics, which consisted of a polycapillary X-ray lens (PCXL) and a tungsten conical pinhole (WCP) for micro X-ray fluorescence (?-XRF) analysis. A single PCXL produced an X-ray micro beam with a spot size of 12 ?m. We developed a WCP by using a laser-ablation technique with an input diameter of 39 ?m, an output diameter of 2.5 ?m, and a thickness of 0.5 mm in a conical shape. This hybrid X-ray optics gave a small spot size of 2.8 ?m with a small divergent angle of 12 mrad.

Komatani, Shintaro; Nakamachi, Kazuo; Nakano, Kazuhiko; Ohzawa, Sumito; Uchihara, Hiroshi; Bando, Atsushi; Tsuji, Kouichi

2013-08-01

35

Introduction to energy-dispersive x-ray fluorescence analysis  

Microsoft Academic Search

The physical principles of energy dispersive x-ray fluorescence analysis are discussed. A phenomenological description of atomic excitation and the subsequent radiation of x rays on which the physical principles are built, is presented. The atomic shell structure and nomenclature, x-ray nomenclature and energies, x-ray intensities and fluorescence yields, and a brief description of the competing Auger and Coster-Kronig transitions are

1978-01-01

36

X-ray fluorescence from the standard sample on HAYABUSA  

NASA Astrophysics Data System (ADS)

In laboratory, X-ray fluorescence analysis has been used with standard samples to determine elemental compositions of materials. X-ray spectrometer on HAYABUSA spacecraft, XRS, carried a standard sample in order to perform comparative analysis. Using this standard sample, the dependency on the variation of induced X-ray, solar X-ray, is reduced, and simultaneous observations of planetary surface and the standard samples improve the determination of the elemental abundance ratio. XRS has five CCDs: one CCD detects the x-rays from the standard sample, and fore CCDs observe the x-rays from the asteroid surface. We report the x-ray fluorescence from the standard sample during the cruising phase. The flux obtained by XRS depended on the solar x-ray observed by GOES satellite, and the x-ray line spectra of Ca and Fe were obtained together with Mg, Al, and Si when solar flare happened.

Yamamoto, Y.; Arai, T.; Okada, T.; Shirai, K.; Ogawa, K.; Kato, M.

37

The X-ray Polarimeter Experiment (XPE)  

Microsoft Academic Search

Polarimetric studies will provide a new probe of cosmic x-ray sources, supplying important clues to source geometries and emission mechanisms. However, at the present time there is only one measurement of x-ray polarization from a cosmic source, the OSO-8 detection of 19% linear polarization from the Crab Nebula. We propose a new low cost x-ray polarimeter experiment (XPE), ideally sized

R. F. Elsner; B. D. Ramsey; S. L. O'dell; M. Sulkanen; A. F. Tennant; M. C. Weisskopf; S. Gunji; T. Minamitani; R. A. Austin; J. Kolodziejczak; D. Swartz; G. Garmire; P. Meszaros; G. G. Pavlov

1997-01-01

38

Ti X-Ray Laser Shadowgraphy Experiment  

Microsoft Academic Search

An x-ray laser shadowgraphy experiment was conducted on Xingguang-II laser facility in 1996. A multi-layer spherical mirror was used as an imaging element and a high sensitivity CCD camera as a detector. We measured the near-field image of the Ti x-ray laser beam. With a Ti x-ray laser beam as a backlight source, we obtained a clear Cu mesh image,

Wen-zhong Huang; Su-ping Liu; Han-sheng Peng; Yu-qiu Gu; Qi-ren Zhang; Yu-qin Cai; Yong-lu You; Wei Hong; Yu-tong Li; Shu-tai Chunyu; Shang-jin Yang; Chuan-fei Zhang; Yong-kuan Zhao; Shu-huai Wen; Jie Zhang; Guo-ping Zhang; Tan-xin Zhang

1996-01-01

39

Research in quantitative microscopic X-ray fluorescence analysis  

Microsoft Academic Search

A feasibility study of quantitative elemental microanalysis of biological materials and glass samples by microbeam X-ray fluorescence spectroscopy was completed. The research included testing the homogeneity of existing standards for X-ray fluorescence calibration and verification of a fundamental parameters method for quantitative analysis. The goal was to evaluate the X-ray fluorescence spectrometer as a tool for elemental analysis at the

M. Lankosz; M. Szczerbowska-Boruchowska; J. Chwiej; J. Ostachowicz; A. Simionovici; S. Bohic

2004-01-01

40

Remote X-Ray Diffraction and X-Ray Fluorescence Analysis on Planetary Surfaces.  

National Technical Information Service (NTIS)

The legacy of planetary X-ray Diffraction (XRD) and X-ray Fluorescence (XRF) began in 1960 when W. Parish proposed an XRD instrument for deployment on the moon. The instrument was built and flight qualified, but the Lunar XRD program was cancelled shortly...

D. F. Blake

1999-01-01

41

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

Microsoft Academic Search

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

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

2004-01-01

42

REMOTE X-RAY DIFFRACTION AND X-RAY FLUORESCENCE ANALYSIS ON PLANETARY SURFACES  

Microsoft Academic Search

The legacy of planetary X-ray Diffraction (XRD) and X-ray Fluorescence (XRF) began in 1960 when W. Parish proposed an XRD instrument for deployment on the moon. The instrument was built and flight qualified, but the Lunar XRD program was cancelled shortly before the first human landing in 1969. XRF chemical data have been collected in situ by surface landers on

David F. Blake

43

A Monte Carlo study of x-ray fluorescence in x-ray detectors.  

PubMed

Advances in digital x-ray detector systems have led to a renewed interest in the performance of x-ray phosphors and other detector materials. Indirect flat panel x-ray detector and charged coupled device (CCD) systems require a more technologically challenging geometry, whereby the x-ray beam is incident on the front side of the scintillator, and the light produced must diffuse to the back surface of the screen to reach the photoreceptor. Direct detector systems based on selenium have also enjoyed a growing interest, both commercially and academically. Monte Carlo simulation techniques were used to study the x-ray scattering (Rayleigh and Compton) and the more prevalent x-ray fluorescence properties of seven different x-ray detector materials, Gd2O2S, CsI, Se, BaFBr, YTaO4, CaWO4, and ThO2. The redistribution of x-ray energy, back towards the x-ray source, in a forward direction through the detector, and lateral reabsorption in the detector was computed under monoenergetic conditions (1 keV to 130 keV by 1 keV intervals) with five detector thicknesses, 30, 60, 90, 120, and 150 mg/cm2 (Se was studied from 30 to 1000 mg/cm2). The radial distribution (related to the point spread function) of reabsorbed x-ray energy was also determined. Representative results are as follows: At 55 keV, more (31.3%) of the incident x-ray energy escaped from a 90 mg/cm2Gd2O2S detector than was absorbed (27.9%). Approximately 1% of the total absorbed energy was reabsorbed greater than 0.5 mm from the primary interaction, for 90 mg/cm2 CsI exposed at 100 kVp. The ratio of reabsorbed secondary (fluorescence + scatter) radiation to the primary radiation absorbed in the detectors (90 mg/cm2) (S/P) was determined as 10%, 16%, 2%, 12%, 3%, 3%, and 0.3% for a 100 kVp tungsten anode x-ray spectrum, for the Gd2O2S, CsI, Se, BaFBr, YTaO4, CaWO4, and ThO2 detectors, respectively. The results indicate significant x-ray fluorescent escape and reabsorption in common x-ray detectors. These findings suggest that x-ray fluorescent radiation redistribution should be considered in the design of digital x-ray imaging systems. PMID:10436891

Boone, J M; Seibert, J A; Sabol, J M; Tecotzky, M

1999-06-01

44

X-ray Fluorescence Spectroscopy of Novel Materials  

Microsoft Academic Search

This review focuses on the capabilities and potential of soft x-ray fluorescence spectroscopy for the study of the electronic\\u000a structure and chemical bonding of novel materials. The basic principle of x-ray fluorescence measurements using synchrotron\\u000a radiation and the corresponding instrumentation issues are outlined. Particular attention is given to x-ray spectroscopic\\u000a studies of the electronic structure and characterization of nanostructures, thin

E. Z. Kurmaev

2005-01-01

45

PARTICULATE MATTER ELEMENTAL COMPOSITION BY X-RAY FLUORESCENCE ANALYSIS  

EPA Science Inventory

This task is primarily concerned with the elemental characterization, by X-ray fluorescence analysis, of particulate matter (PM) collected during active or passive sampling of ambient air. The NERL X-ray fluorescence laboratory is an in-house research facility dedicated to quant...

46

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

Microsoft Academic Search

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

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

2004-01-01

47

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

NASA Astrophysics Data System (ADS)

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 X-ray fluorescence. This work presents a compilation of data sets from different published works and an xraylib interface in the form of callable functions. Although the target applications are on X-ray fluorescence, cross sections of interactions like photoionization, coherent scattering and Compton scattering, as well as form factors and anomalous scattering functions, are also available.

Brunetti, A.; Sanchez Del Rio, M.; Golosio, B.; Simionovici, A.; Somogyi, A.

2004-10-01

48

Coded aperture imaging for fluorescent x-rays  

NASA Astrophysics Data System (ADS)

We employ a coded aperture pattern in front of a charge couple device (CCD) pixilated detector to image fluorescent xrays (6-25KeV) from samples irradiated with synchrotron radiation. Coded apertures encode the angular direction of xrays, and given a known source plane, allow for a large Numerical Aperture x-ray imaging system. The algorithm to develop the free standing coded aperture pattern of the Non-Two-Holes-Touching (NTHT) was developed. The algorithms to reconstruct the x-ray image from the encoded pattern recorded are developed by means of modeling and confirmed by experiments on standard samples. Spatial resolution and efficiency are determined for the next development stage whereby an energy resolving pixilated CCD will be deployed allowing for elemental imaging.

Haboub, A.; MacDowell, A. A.; Marchesini, S.; Parkinson, D. Y.

2012-10-01

49

X-ray Background Signals in Total Reflection X-ray Fluorescence Spectroscopy  

Microsoft Academic Search

Total Reflection X-ray Fluorescence Spectroscopy (TXRF) is widely used for wafer surface analysis. An important figure of merit is its sensitivity, defined as 3*signal\\/sqrt(background). Since the signals can be small compared to the background, it is essential to fully understand the background components when considering possible improvements. This talk describes recent experimental and theoretical progress in understanding the X-ray background

N. Takaura; A. Waldhauer; S. Brennan; P. Pianetta; S. S. Laderman; A. Fischer-Colbrie

1996-01-01

50

Rapid Determination of Uranium by X-Ray Fluorescence.  

National Technical Information Service (NTIS)

This report describes a method for rapidly determining the amount of uranium using x-ray fluorescence. We add an aliquot of sample solution plus the internal standard element, Yttrium, to a 10-ml volumetric flask. We transfer this solution to an x-ray cel...

C. J. Martell J. M. Hansel

1987-01-01

51

[Development of X-ray excited fluorescence spectrometer].  

PubMed

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

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

2009-08-01

52

Magnetic Circular Dichroism in X-ray Fluorescence Cascade Processes  

NASA Astrophysics Data System (ADS)

The excellent performances of our 35-element Silicon Drift Diode detector over a very wide energy range (>=0.5 keV), allowed us to investigate the existence of magnetic circular dichroism in X-ray fluorescence cascade processes. We report the results of a test experiment performed at the Tb LIII-edge using an amorphous TbCo2 thin film which was magnetically saturated with an external magnetic field of 0.5 T. In a single energy scan, two XMCD spectra were obtained by monitoring separately the integrated intensities of L? and M? emission lines of the Tb atoms.

Rogalev, A.; Goulon, J.; Wilhelm, F.; Jaouen, N.; Goujon, G.

2007-01-01

53

X-ray fluorescence/diffraction analyzer for the SELENE-B lander/rover mission  

NASA Astrophysics Data System (ADS)

A miniaturized X-ray fluorescence and diffraction analyzer is being developed for the SELENE-B, a future Japanese lunar lander and rover mission, to analyze major elemental composition and mineralogy. An onboard micro X-ray tube with a fine focus collimator is used to generate primary X-rays that excite fluorescence X-rays characteristic of major elements in collected samples; the primary X-rays are also scattered into X-ray diffraction pattern reflecting lattice structures of the component minerals. By using a two-dimensional charge-coupled device, pulse height analysis for XRF and diffraction pattern extraction for XRD will be simultaneously carried out. The instrument covers an energy detection range from 1 to 10 KeV and measures diffraction angles from 20 to 60 degrees for elemental and mineral analysis, respectively. We show the results of laboratory experiments conducted with alumina powder.

Shirai, K.; Aoki, M.; Okada, T.; Yamamoto, Y.; Arai, T.; Akagawa, K.; Kato, M.

2003-06-01

54

Are Atom-sized X-ray Experiments Possible?  

SciTech Connect

The success of advanced microbeam facilities at third generation synchrotron sources have inspired us to ask ultimate questions such as how small an x-ray beam diameter can be made. With the hope of more brilliant Energy Recovery Linac or X-ray Free Electron Laser sources due to arrive in the next decade, it appears possible to think of fluorescent x-ray experiments that can be performed on even a single impurity atom in a silicon wafer, for instance. Not all x-ray optical developers are yet convinced, however, so there is critical need to assess whether in principle this can really be done or not. We are optimistic that 1 nm diameter x-ray beams can be made of sufficient flux from future sources or even demonstration experiments at lower count rates from 3rd generation sources if it turns out to be worthwhile to actively develop optics and methods that vastly exceed the current x-ray microbeam capabilities.

Bilderback, Donald H. [Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853 (United States); School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853 (United States); Huang Rong [Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853 (United States)

2004-05-12

55

X-Ray Fluorescence Analysis of Uranium Concentrates.  

National Technical Information Service (NTIS)

Uranium concentrates were analyzed by x-ray fluorescence for the following impurities: arsenic, calcium, iron, molybdenum, phosphorus, silicon, sulfur, thorium, and vanadium. All of the impurities except arsenic can be determined simultaneously. (ERA cita...

J. P. Diaz-Guerra A. Bayon M. Roca

1985-01-01

56

Polarization Excitation Device for X-Ray Fluorescence Analysis.  

National Technical Information Service (NTIS)

The patent application is a device for improving the sensitivity for elemental analysis by X-ray fluorescence using energy dispersive detectors. Samples are analyzed for their trace elemental composition by irradiating the samples with a beam of nearly mo...

T. G. Dzubay

1974-01-01

57

Recoil splitting of x-ray-induced optical fluorescence  

SciTech Connect

We show that the anisotropy of the recoil velocity distribution of x-ray-ionized atoms or molecules leads to observable splittings in subsequent optical fluorescence or absorption when the polarization vector of the x rays is parallel to the momentum of the fluorescent photons. The order of the magnitude of the recoil-induced splitting is about 10 {mu}eV, which can be observed using Fourier or laser-absorption spectroscopic techniques.

Gavrilyuk, S.; Aagren, H.; Gel'mukhanov, F. [Theoretical Chemistry, School of Biotechnology, Royal Institute of Technology, S-106 91 Stockholm (Sweden); Sun, Y.-P. [Theoretical Chemistry, School of Biotechnology, Royal Institute of Technology, S-106 91 Stockholm (Sweden); College of Physics and Electronics, Shandong Normal University, 250014 Jinan (China); Levin, S. [Institute for Physics, St. Petersburg University, Uljanovskaya 1, St. Petersburg RU-198904 (Russian Federation)

2010-03-15

58

Recent Advances in Portable X-Ray Fluorescence Spectrometry  

Microsoft Academic Search

X?ray fluorescence (XRF) spectrometry is a nondestructive, rapid, simultaneous multi?element analytical methodology for solid or liquid samples. Its applications are broad and XRF spectra cover most elements, with a dynamic range from 100% down to the ľg\\/g level. X-ray fluorescence is a well?established laboratory?based method, but it is also one of the few atomic spectrometric techniques that can be used

Xiandeng Hou; Yihua He; Bradley T. Jones

2004-01-01

59

Determination of regional myocardial perfusion by x-ray fluorescence  

Microsoft Academic Search

Validation studies were performed to demonstrate the effectiveness of an x-ray induced fluorescence system in quantitating regional myocardial perfusion in vivo. In a series of 13 open-chested canines, x-ray induced fluorescence was used to simultaneously monitor iodine concentration transients which arose in the left ventricular lumen and in the myocardium after the intravenous injection of an iodinated flow tracer. Deconvolution

BRADLEY M. PALMER; JOSEPH J. MCINERNEY

1990-01-01

60

X-ray fluorescence analysis based on Kumakhov optics  

NASA Astrophysics Data System (ADS)

The use of Kumakhov optics in x-ray fluorescence analysis is considered. Thanks to high efficiency of a polycapillary lens the concentration of x-ray detector in a close proximity to the sample decreases sufficiently the time of exposure. It is shown experimentally that in the case of use of a small x-ray source with power of 2W the minimal detection limit may be of the order of 0.1 pg. A new portable x-ray fluorescence analyzer based on Kumakhov optics is described. Minimal detection limit may achieve 10(superscript -16) g if 100 W microfocus source and the lens with approximately 10 micrometers focal spot are used.

Nikitina, Svetlana V.; Ibraimov, Nariman S.; Stcherbakov, Alexander S.

1998-11-01

61

X-Ray Fluorescence With a Krypton Gas Proportional Counter  

NASA Astrophysics Data System (ADS)

X-Ray fluorescence analysis of potential meteorites can provide evidence of the typical iron and nickel content of certain classes of meteorites. The resolution of a Krypton-Carbon Dioxide filled proportional counter is sufficient to resolve the K X-rays of these low Z elements. The detector operates at room temperature, and the associated electronic circuit is simple and can be assembled quickly.

Peterson, David

2007-11-01

62

X-ray fluorescence and the study of microcirculation  

Microsoft Academic Search

The feasibility of using K-shell X-ray fluorescence (XRF) technique for study of subchondral bone microcirculation in ex vivo samples is examined. Studies have been carried out at the Daresbury Laboratory Synchrotron Radiation Source (SRS) ultra-dilute extended X-ray absorption fine structure beamline. Initial investigations were made on fine-bore capillaries with diameters of either 500 or 200 ?m, attenuated by up to

P. Muthuvelu; R. P. Hugtenburg; D. A. Bradley; C. P. Winlove

2004-01-01

63

Capillary optics for micro x-ray fluorescence analysis  

NASA Astrophysics Data System (ADS)

Practically achieved parameters of capillary optics are presented. A micro x-ray fluorescence (XRF) arrangement was realized by using a microfocus x-ray tube and a capillary optic. Several examples for application of micro XRF are given. It was shown that polycapillary lenses free of the ``halo effect'' well suited for micro XRF of heavy elements can be manufactured. Limits of opportunities for micro XRF applications and further development for micro XRF by using capillary optics are analyzed.

Bjeoumikhov, A.; Langhoff, N.; Bjeoumikhova, S.; Wedell, R.

2005-06-01

64

Sampling the Soils around a Residence Containing Lead-Based Paints: An X-Ray Fluorescence Experiment  

ERIC Educational Resources Information Center

|Sampling experiments utilizing field portable instruments are instructional since students collect data following regulatory protocols, evaluate it, and begin to recognize their civic responsibilities upon collecting useful data. A lead-in-soil experiment educated students on a prevalent exposure pathway. The experimental site was a pre-1950…

Bachofer, Steven J.

2008-01-01

65

K and L shell x-ray fluorescence cross sections  

SciTech Connect

The K and L shell x-ray fluorescence (XRF) cross sections for elements with 13 {le} Z {le} 92 and 35 {le} Z {le} 92, respectively, are calculated for an incident photon energy range 1-200 keV. The XRF cross sections for K{alpha}, K{beta}, Ll, L{alpha}, L{beta}, and L{gamma} groups of x rays are tabulated. These calculations use the comprehensive sets of physical parameters currently considered most reliable, namely, theoretical partial photoionization cross sections and x-ray emission rates of Scofield, K shell fluorescence yields compiled by Hubbell, and L{sub i} subshell fluorescence yields, Coster-Kronig transition probabilities, and K to L{sub i} subshell vacancy-transfer probabilities based on the Dirac-Hartree-Slater model. 28 refs., 3 figs., 2 tabs.

Puri, S.; Chand, B.; Mehta, D. [Panjab Univ., Chandigarn (India)

1995-11-01

66

Human thyroid specimen imaging by fluorescent x-ray computed tomography with synchrotron radiation  

Microsoft Academic Search

Fluorescent x-ray computed tomography (FXCT) is being developed to detect non-radioactive contrast materials in living specimens. The FXCT system consists of a silicon (111) channel cut monochromator, an x-ray slit and a collimator for fluorescent x ray detection, a scanning table for the target organ and an x-ray detector for fluorescent x-ray and transmission x-ray. To reduce Compton scattering overlapped

Tohoru Takeda; Quanwen Yu; Toru Yashiro; Tetsuya Yuasa; Yasuo Hasegawa; Yuji Itai; Takao Akatsuka

1999-01-01

67

X-ray Methods in High-Intensity Discharges and Metal-Halide Lamps: X-ray Induced Fluorescence  

SciTech Connect

We describe the use of x-ray induced fluorescence to study metal-halide high-intensity discharge lamps and to measure equilibrium vapor pressures of metal-halide salts. The physical principles of metal-halide lamps, relevant aspects of x-ray-atom interactions, the experimental method using synchrotron radiation, and x-ray induced fluorescence measurements relevant to metal-halide lamps are covered.

Curry, John J.; Lapatovich, Walter P.; Henins, Albert (NIST)

2011-12-09

68

Diffraction and holography of photoelectrons and fluorescent x-rays  

SciTech Connect

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.

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

1993-04-01

69

Aluminum impurities in silicon: Investigation of x-ray Raman scattering in total reflection x-ray fluorescence spectroscopy  

Microsoft Academic Search

Total reflection x-ray fluorescence using synchrotron radiation from the Stanford Synchrotron Radiation Laboratory has been used to study Al impurities on Si wafer surfaces. For primary excitation energies below the Si K absorption edge an inelastic resonance scattering due to resonant x-ray Raman scattering is observed. This scattering dominates the background behavior of the Al K fluorescence line, and consequently

K. Baur; J. Kerner; S. Brennan; A. Singh; P. Pianetta

2000-01-01

70

Archaeometrical studies using X-ray fluorescence methods  

SciTech Connect

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.

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

71

Archaeometrical studies using X-ray fluorescence methods  

NASA Astrophysics Data System (ADS)

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.

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

2010-04-01

72

X-ray fluorescence analysis major elements in silicate minerals  

SciTech Connect

An automated wavelength-dispersive x-ray fluorescence spectrometer is operational for analysis of major elements in rocks and minerals. Procedures for trace-element analysis are being developed. Sample preparation methods and analytical techniques are similar to those commonly used elsewhere, but data reduction is conducted by the Fundamental Parameters program developed by Criss. Unlike empirically derived calibration curves, this data reduction method considers x-ray absorption and secondary fluorescence, which vary with differences in sample composition. X-ray intensities for each element from several standards are averaged to develop a theoretical standard for comparison with samples of unknown composition. Accurate data for samples with wide compositional ranges result from these data reduction and standardization techniques.

Hagan, R.C.

1982-09-01

73

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

NASA Astrophysics Data System (ADS)

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.

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

2013-09-01

74

Synchrotron radiation induced X-ray fluorescence at LURE  

Microsoft Academic Search

Advantages of X-ray fluorescence with the use of Synchrotron Radiation are emphasized (intensity, polarization, tunability of energy). The experimental set-up and the fast computer system for the data reduction without standards are presented. The results are in good agreement with standard references. Examples of applications are presented: old coins and potteries were studied in archaeological domain; metal alloys were analyzed;

I. Brissaud; J. X. Wang; P. Chevallier

1989-01-01

75

Soft x-ray fluorescence spectroscopy using tunable synchrotron radiation  

Microsoft Academic Search

The introduction of high brightness synchrotron radiation sources has opened up new possibilities for using soft x-ray fluorescence spectroscopy in the study of electronic structure. Selective excitation allows site specific emission to be studied, satellite structure due to multiple excitation to be separated, resonant phenomena to be investigated, etc. In particular, it has been found that inelastic scattering becomes dominating

Joseph E. Nordgren; Nial Wassdahl

1995-01-01

76

Evaluating the variability of ceramics with x-ray fluorescence  

Microsoft Academic Search

Our assessment of prehistoric trade in ceramics depends on our ability to identify and distinguish different sources of manufacture. For the American Southwest, archaeologists have proposed various models of ceramic manufacture and exchange. Until recently, conflicting hypotheses were tested mainly on the basis of petrographic analysis of nonplastic tempering materials. We have extended these analyses to include x-ray fluorescence (XRF).

P. L. Crown; L. A. Schwalbe; J. R. London

1984-01-01

77

X-ray Fluorescent Phosphors as in Situ Markers of X-ray Position for High-Pressure X-ray Techniques: Equation of State and X-ray Fluorescence Spectra to 40 GPa  

Microsoft Academic Search

Their small size and heterogeneity make high-pressure samples in the diamond-anvil cell difficult to place perfectly in an x-ray beam to perform any of several analytical techniques (diffraction, scattering, etc.). X-ray fluorescent materials may help to solve this problem by providing a visual marker of the precise location of the x-ray beam or probe. In order to assess the utility

L. R. Benedetti; W. A. Crichton; M. Mezouar

2004-01-01

78

Synchrotron radiation x-ray fluorescence analysis  

SciTech Connect

Synchrotron radiation can be used for XFA to increase the sensitivity by a factor of 10-100 by comparison with that available from traditional fluorescence-excitation sources. The advantages of SR are fully realized with thin specimens (20-100 mg/cm/sup 2/) with the beam focused on an area of 1 mm/sup 2/ or less. Such a beam can be used to analyze small specimens (less than 1 mg) and also to examine element distribution with high spatial resolution.

Baryshev, V.B.; Kolmogorov, Yu.P.; Kulipanov, G.N.; Skrinskii, A.N.

1986-08-20

79

Fluorescence imaging of Dictyostelium discoideum with a hard X-ray nanoprobe  

NASA Astrophysics Data System (ADS)

The preparation and a novel sample environment for X-ray based imaging of freeze-dried Dictyostelium discoideum cells are presented. As a first application a fluorescence imaging experiment with a nanofocused hard X-ray beam has been performed. The successful preparation was verified in elemental mappings with sub-200nm resolution, which allowed for the isolation of several ionic components specific to the cell body.

Giewekemeyer, K.; Hantke, M.; Beta, C.; Tucoulou, R.; Salditt, T.

2009-09-01

80

Tentative study on x-ray enhancement by fluorescent emission of radiation by plasma x-ray source  

Microsoft Academic Search

Tentative study on characteristic x-ray enhancement by fluorescent emission of radiation by plasma x-ray source is described. The enhancement was performed by the plasma flash x-ray generator having a cold-cathode triode. And the generator employs a high-voltage power supply, a low-impedance coaxial transmission line with a gap switch, a high-voltage condenser with a capacity of 200 nF, a turbo-molecular pump,

Eiichi Sato; Michiaki Sagae; Toshio Ichimaru; Yasuomi Hayasi; Hidenori Ojima; Kazuyoshi Takayama; Hideaki Ido; Kimio Sakamaki; Yoshiharu Tamakawa

1999-01-01

81

X-ray absorption and soft x-ray fluorescence analysis of KDP optics  

SciTech Connect

Potassium Dihydrogen Phosphate (KDP) is a non-linear optical material used for laser frequency conversion and optical switches. Unfortunately, when KDP crystals are coated with a porous silica anti-reflection coating [1] and then exposed to ambient humidity, they develop dissolution pits [2,3]. Previous investigations [2] have shown that thermal annealing renders KDP optics less susceptible to pitting suggesting that a modification of surface chemistry has occurred. X-ray absorption and fluorescence were used to characterize changes in the composition and structure of KDP optics as a function of process parameters. KDP native crystals were also analyzed to provide a standard basis for interpretation. Surface sensitive total electron yield and bulk sensitive fluorescence yield from the K 2p, P 2p (L{sub 2,3}-edge) and O 1s (K-edge) absorption edges were measured at each process step. Soft X-ray fluorescence was also used to observe changes associated with spectral differences noted in the absorption measurements. Results indicate that annealing at 160 C dehydrates the surface of KDP resulting in a metaphosphate surface composition with K:P:O = 1:1:3.

Nelson, A J; van Buuren, T; Miller, E; Land, T A; Bostedt, C; Franco, N; Whitman, P K; Baisden, P A; Terminello, L J; Callcott, T A

2000-08-09

82

Silver coins analyses by X-ray fluorescence methods.  

PubMed

The investigation on the differences occurring in the manufacture of silver coins allows to get information on their elemental composition and represents a powerful support to the methodology to identify the producing technologies, workshops being also instrumental to distinguish between original and counterfeit ones. Aim of the present work is to study recent and old silver coins through non-destructive X-Ray Fluorescence (XRF) analysis. The XRF was applied to extend the analysis to the deepest layers of the coins; for surface layers an X-ray tube or an electron beam were employed to induce the atom fluorescence to obtain information on the surface elemental composition. Moreover, a detailed study has been performed to evaluate the influence of the surface curvature on the measurement, by deducing a proper corrective factor to keep into account in the data analysis. The elemental atomic composition was measured for each coin, mainly by means of the X-ray tube excitation for the bulk and the electron Scanning Electron Microscope (SEM) microbeam probe for the surface patina analysis. Ionization was induced by an X-ray tube using an Ag anode for the bulk and by an electron microprobe for the surface composition. X-ray detection was performed by using a semiconductor Si device cooled by a Peltier system. The Ag L-lines X-ray yield is affected by coin surface morphology and geometry. The comparison between coin spectra and standard samples, shows that the Ag quantitative analysis is influenced by error of the atomic concentration lower that 10%. PMID:24004868

Torrisi, L; Italiano, A; Cutroneo, M; Gentile, C; Torrisi, A

2013-01-01

83

A library for X-ray-matter interaction cross sections for X-ray fluorescence applicationsB  

Microsoft Academic Search

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

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

84

Fluorescent x-ray computed tomography to visualize specific material distribution  

Microsoft Academic Search

Fluorescent x-ray computed tomography (FXCT) is being developed to detect non-radioactive contrast materials in living specimens. The FXCT systems consists of a silicon channel cut monochromator, an x-ray slit and a collimator for detection, a scanning table for the target organ and an x-ray detector for fluorescent x-ray and transmission x-ray. To reduce Compton scattering overlapped on the K(alpha) line,

Tohoru Takeda; Tetsuya Yuasa; Atsunori Hoshino; Masahiro Akiba; Akira Uchida; Masahiro Kazama; Kazuyuki Hyodo; F. Avraham Dilmanian; Takao Akatsuka; Yuji Itai

1997-01-01

85

Determination of regional myocardial perfusion by x-ray fluorescence  

SciTech Connect

Validation studies were performed to demonstrate the effectiveness of an x-ray induced fluorescence system in quantitating regional myocardial perfusion in vivo. In a series of 13 open-chested canines, x-ray induced fluorescence was used to simultaneously monitor iodine concentration transients which arose in the left ventricular lumen and in the myocardium after the intravenous injection of an iodinated flow tracer. Deconvolution of the recorded transients produced a transfer function from which the mean transit time for the tracer to travel between the left ventricular lumen and the myocardium was calculated. Measurements of regional myocardial perfusion (Q) made by radioactive microspheres were compared with the reciprocals of the mean transit times (MTT-1) and gave a linear correlation (n = 38): MTT-1 = 0.033 + 0.069 Q, r = 0.71. Comparison of the percent change in perfusion (dQ) relative to a control study for each dog with the percent change in the respective reciprocals of the mean transit times (dMTT-1) produced a linear correlation coefficient of r = 0.88 for the regression line dMTT-1 = 0.46 dQ - 10.7. The x-ray induced fluorescence system may provide a minimally invasive means for monitoring iodine concentration transients and determining relative, if not absolute, measures of regional myocardial perfusion.

Palmer, B.M.; McInerney, J.J. (Pennsylvania State Univ., University Park (USA))

1990-05-01

86

Identifications studies of Lauha Bhasma by X-ray diffraction and X-ray fluorescence.  

PubMed

Procedures for preparation of Lauha Bhasma are described in ancient texts of Ayurveda. These procedures also begin with different source material for iron such as Teekshna Lauha and Kanta Lauha etc. In the present study, we have selected different source materials viz. magnetite iron ore for Kanta Lauha and pure (Armco grade) iron turnings for Teekshna Lauha. The standard procedures of preparation of Lauha Bhasma are carried out in identical conditions for these two raw materials. The final product from the Puta are characterized by using X-ray diffraction and X-ray fluorescence spectroscopy to understanding the crystallographic form or forms of iron oxides and their composition at the end of each Puta. The iron content at the end of repeated Putas (18 for Kanta Lauha and 20 for Teekshna Lauha) have shown a decrease in case of Teekshna Lauha since the starting material is pure iron while it showed only marginal decreases in the case of Kanta Lauha because the Fe(3)O(4) of magnetite is undergoing oxidation to Fe(2)O(3). The trace elements remain within the Bhasma in the form of various oxides of Si, Al, Ca, etc. PMID:23049200

Bhargava, S C; Reddy, K R C; Sastry, G V S

2012-01-01

87

Identifications studies of Lauha Bhasma by X-ray diffraction and X-ray fluorescence  

PubMed Central

Procedures for preparation of Lauha Bhasma are described in ancient texts of Ayurveda. These procedures also begin with different source material for iron such as Teekshna Lauha and Kanta Lauha etc. In the present study, we have selected different source materials viz. magnetite iron ore for Kanta Lauha and pure (Armco grade) iron turnings for Teekshna Lauha. The standard procedures of preparation of Lauha Bhasma are carried out in identical conditions for these two raw materials. The final product from the Puta are characterized by using X-ray diffraction and X-ray fluorescence spectroscopy to understanding the crystallographic form or forms of iron oxides and their composition at the end of each Puta. The iron content at the end of repeated Putas (18 for Kanta Lauha and 20 for Teekshna Lauha) have shown a decrease in case of Teekshna Lauha since the starting material is pure iron while it showed only marginal decreases in the case of Kanta Lauha because the Fe3O4 of magnetite is undergoing oxidation to Fe2O3. The trace elements remain within the Bhasma in the form of various oxides of Si, Al, Ca, etc.

Bhargava, S. C.; Reddy, K. R. C; Sastry, G. V. S

2012-01-01

88

Spectrometer for lanthanides' K x-ray fluorescence  

SciTech Connect

X-ray fluorescence analysis is a highly useful technique for determining the chemical composition of matter. The present article describes the successful development of a wavelength-dispersive x-ray fluorescence spectrometer for a fairly high-energy range, 30-60 keV, that can contribute to studying lanthanides' K{beta} spectra with high-energy resolution. By combining a new high-energy synchrotron light source and the present spectrometer, it has been demonstrated that the full width at half maximum for lanthanum's K{beta}{sub 1} is 32 eV and that all the peaks in the spectra are fully resolved. This corresponds to an energy resolution E/{delta}E of 1180, which is ten times better than a conventional system based on a Ge detector, which can detect only two peaks, K{beta}{sub 1} and K{beta}{sub 2}, in seven peaks. The present spectrometer can open up a new field in x-ray spectrometry.

Sakurai, Kenji; Mizusawa, Mari; Terada, Yasuko [National Institute for Materials Science, Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Japan Synchrotron Radiation Research Institute, SPring-8, Sayo-gun, Hyogo 679-5198 (Japan)

2007-06-15

89

Flash X-ray diagnostics of argon jets: X-ray induced fluorescence imaging and radiography  

Microsoft Academic Search

Summary form only given. In this work we report on the development and application of two flash X-ray diagnostic techniques. A compact X-ray source specially designed for these studies was used to characterize argon flows at atmospheric pressure in ambient air. The table-top X-ray source emits strong doses of X-ray photons of about 10 keV in pulses of 20 ns

L. Hure; E. Robert; C. Cachoncinlle; R. Viladrosa; J. M. Pouvesle

1999-01-01

90

Proton induced quasi-monochromatic x-ray beams for soft x-ray spectroscopy studies and selective x-ray fluorescence analysis.  

PubMed

We present the analytical features and performance of an x-ray spectroscopy end station of moderate energy resolution operating with proton-induced quasi-monochromatic x-ray beams. The apparatus was designed, installed and operated at the 5.5 MV Tandem VdG Accelerator Laboratory of the Institute of Nuclear Physics, N.C.S.R. "Demokritos," Athens. The setup includes a two-level ultrahigh vacuum chamber that hosts in the lower level up to six primary targets in a rotatable holder; there, the irradiation of pure element materials-used as primary targets-with few-MeV high current (~?A) proton beams produces intense quasi-monochromatic x-ray beams of selectable energy. In the chamber's upper level, a six-position rotatable sample holder hosts the targets considered for x-ray spectroscopy studies. The proton-induced x-ray beam, after proper collimation, is guided to the sample position whereas various filters can be also inserted along the beam's path to eliminate the backscattered protons or/and to absorb selectively components of the x-ray beam. The apparatus incorporates an ultrathin window Si(Li) spectrometer (FWHM 136 eV at 5.89 keV) coupled with low-noise electronics capable of efficiently detecting photons down to carbon K?. Exemplary soft x-ray spectroscopy studies and results of selective x-ray fluorescence analysis are presented. PMID:23277967

Sokaras, D; Zarkadas, Ch; Fliegauf, R; Beckhoff, B; Karydas, A G

2012-12-01

91

Proton induced quasi-monochromatic x-ray beams for soft x-ray spectroscopy studies and selective x-ray fluorescence analysis  

SciTech Connect

We present the analytical features and performance of an x-ray spectroscopy end station of moderate energy resolution operating with proton-induced quasi-monochromatic x-ray beams. The apparatus was designed, installed and operated at the 5.5 MV Tandem VdG Accelerator Laboratory of the Institute of Nuclear Physics, N.C.S.R. 'Demokritos,' Athens. The setup includes a two-level ultrahigh vacuum chamber that hosts in the lower level up to six primary targets in a rotatable holder; there, the irradiation of pure element materials-used as primary targets-with few-MeV high current ({approx}{mu}A) proton beams produces intense quasi-monochromatic x-ray beams of selectable energy. In the chamber's upper level, a six-position rotatable sample holder hosts the targets considered for x-ray spectroscopy studies. The proton-induced x-ray beam, after proper collimation, is guided to the sample position whereas various filters can be also inserted along the beam's path to eliminate the backscattered protons or/and to absorb selectively components of the x-ray beam. The apparatus incorporates an ultrathin window Si(Li) spectrometer (FWHM 136 eV at 5.89 keV) coupled with low-noise electronics capable of efficiently detecting photons down to carbon K{alpha}. Exemplary soft x-ray spectroscopy studies and results of selective x-ray fluorescence analysis are presented.

Sokaras, D. [Institute of Nuclear Physics, N.C.S.R. Demokritos, Aghia Paraskevi, 15310 Athens (Greece); Zarkadas, Ch. [PANalytical B.V., 7600 AA Almelo (Netherlands); Fliegauf, R.; Beckhoff, B. [Physikalisch-Technische Bundesanstalt, Abbestrasse 2-12, 10587 Berlin (Germany); Karydas, A. G. [Institute of Nuclear Physics, N.C.S.R. Demokritos, Aghia Paraskevi, 15310 Athens (Greece); Nuclear Spectrometry and Applications Laboratory, IAEA Laboratories, A-2444 Seibersdorf (Austria)

2012-12-15

92

X-Ray Astronomy Discovery Experiments, II  

NASA Astrophysics Data System (ADS)

Paper I provided proof of concurrent discovery experiments at the start of cosmic x-ray source studies. It was noted that since the Lockheed discovery was postulated before any source was observed, that discovery was of equal or greater importance to the start of such studies than the discovery of Sco X-1. Illusions about the nonexistence of the Lockheed discovery that may have been caused by organizers and invited reviewers of a meeting, and related events (including A. E. Whitford, private communication (1975). and, R. Giacconi, Les Prix Nobel, Nobel Foundation, Stockholm, Sweden, p. 114 (2003). will be described. This paper's goal is to have the American Institute of Physics require members to properly credit contributions of others. P. C. Fisher, BAPS 53 No. 2, 165 (2008). S. B. Pikelner et al., Transactions of the IAU (L. Perek ed.), D. Reidel, Dordrecht/Holland and Springer-Verlag, New York XIIIA, p. 179 (1968). H. Friedman, op cit, p.180. R. Giacconi, op cit, p. 184.

Fisher, P. C.

2009-05-01

93

Applications of synchrotron x-ray fluorescence to extraterrestrial materials  

SciTech Connect

Synchrotron x-ray fluorescence (SXRF) is a valuable technique for trace element analyses of extraterrestrial materials permitting minimum detection limits less than 1 ppM for 20 micrometer spots. SXRF measurements have been performed on iron meteorites and micrometeorites using white synchrotron radiation and an energy dispersive x-ray detector at the National Synchrotron Light Source (X-26C), Brookhaven National Laboratory (NY). Partitioning of Cu between troilite (FeS) and metal in the nine iron meteorites studied suggests sub-solidus re-equilibration in these objects. A technique has been developed for determining self-absorption corrections for filtered, continuum excitation of small specimens, such as stratospheric particles and refractory inclusions in meteorites.

Sutton, S.R.; Rivers, M.L.; Smith, J.V.

1986-01-01

94

Micro-X-ray Fluorescence in Food Forensics  

NASA Astrophysics Data System (ADS)

All forms of commercially available x-ray microscopy are finding growing application opportunities within the food industry; this includes micro-x-ray fluorescence (micro-XRF) and micro-CT. In this example, we demonstrate the use of micro-XRF in discovering the cause for a particularly troubling anomaly discovered by one of our customers during the production of a batch of their chicken hotdogs. Although their claim was that iron filings must be present to cause such anomalies, no ``iron filings'' were discovered in our initial observations. More traditional EDS methods were attempted to determine the elemental content within these anomalies, but they were not sensitive enough to detect the small amounts of iron that were, in fact, present. Nor could EDS determine the source for this minute amount of iron. Only micro-XRF displayed the required sensitivity to detect the iron and to make an initial diagnosis regarding its potential source. Visible spectroscopy confirms. Instrumentation is reviewed.

St. Jeor, V. L.; Muroski, A. R.; McGuire, C.; Lape, A.

2011-09-01

95

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

NASA Astrophysics Data System (ADS)

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.

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

2009-04-01

96

X-Ray Fluorescence On-Stream Analysis of Standard Reference Solution Concentrations of Chromium Plating and Polishing Solutions.  

National Technical Information Service (NTIS)

X-ray fluorescence is evaluated as a means to quantitatively analyze standard reference solution concentrations of chromium plating and polishing solutions for chromium, sulfur, phosphorus, and iron in a continuous, on-stream fashion. The identical experi...

S. Sopok

1991-01-01

97

Combined use of hard X-ray phase contrast imaging and X-ray fluorescence microscopy for sub-cellular metal quantification.  

PubMed

Hard X-ray fluorescence microscopy and magnified phase contrast imaging are combined to obtain quantitative maps of the projected metal concentration in whole cells. The experiments were performed on freeze dried cells at the nano-imaging station ID22NI of the European Synchrotron Radiation Facility (ESRF). X-ray fluorescence analysis gives the areal mass of most major, minor and trace elements; it is validated using a biological standard of known composition. Quantitative phase contrast imaging provides maps of the projected mass and is validated using calibration samples and through comparison with Atomic Force Microscopy and Scanning Transmission Ion Microscopy. Up to now, absolute quantification at the sub-cellular level was impossible using X-ray fluorescence microscopy but can be reached with the use of the proposed approach. PMID:22182730

Kosior, Ewelina; Bohic, Sylvain; Suhonen, Heikki; Ortega, Richard; Devčs, Guillaume; Carmona, Asuncion; Marchi, Florence; Guillet, Jean Francois; Cloetens, Peter

2011-12-11

98

The Polar Ionospheric X-ray Imaging Experiment (PIXIE)  

Microsoft Academic Search

The Polar Ionospheric X-ray Imaging Experiment (PIXIE) is an X-ray multiple-pinhole camera designed to image simultaneously an entire auroral region from high altitudes. It will be mounted on the despun platform of the POLAR spacecraft and will measure the spatial distribution and temporal variation of auroral X-ray emissions in the 2 to 60 keV energy range on the day side

W. L. Imhof; K. A. Spear; J. W. Hamilton; B. R. Higgins; M. J. Murphy; J. G. Pronko; R. R. Vondrak; D. L. McKenzie; C. J. Rice; D. J. Gorney; D. A. Roux; R. L. Williams; J. A. Stein; J. Bjordal; J. Stadsnes; K. Njoten; T. J. Rosenberg; L. Lutz; D. Detrick

1995-01-01

99

HIGH RESOLUTION X-RAY FLUORESCENCE MEASUREMENTS USING A FLAT ANALYZER CRYSTAL AND AN X-RAY CCD  

Microsoft Academic Search

High resolution X-ray fluorescence measurements were carried out using a flat analyzer crystal and an X-ray CCD (charge-coupled device). A comparison of the detector was made between the CCD and the position sensitive proportional counter (PSPC), and the advantage of the CCD in better spatial resolution and two-dimensional spatial resolution was demonstrated. Full width at half maximum (FWHM) of measured

Shinjiro Hayakawa; Yasushi Kagoshima; Yoshiyuki Tsusaka; Junji Matsui; Takeshi Hirokawa

2001-01-01

100

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

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

101

Evaluating the variability of ceramics with x-ray fluorescence  

SciTech Connect

Our assessment of prehistoric trade in ceramics depends on our ability to identify and distinguish different sources of manufacture. For the American Southwest, archaeologists have proposed various models of ceramic manufacture and exchange. Until recently, conflicting hypotheses were tested mainly on the basis of petrographic analysis of nonplastic tempering materials. We have extended these analyses to include x-ray fluorescence (XRF). XRF provides a fast and inexpensive means of analyzing large numbers of samples. Since 1982, approximately 500 prehistoric sherds and 40 prepared clay and mineral samples have been examined with XRF. Multivariate statistical techniques have been applied to help identify groupings of samples with possible archaeological significance.

Crown, P.L.; Schwalbe, L.A.; London, J.R.

1984-01-01

102

Portable X-ray Fluorescence Unit for Analyzing Crime Scenes  

NASA Astrophysics Data System (ADS)

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

Visco, A.

2003-12-01

103

Basic principles of Synchrotron Radiation-Induced X-Ray Fluorescence (SRXRF).  

National Technical Information Service (NTIS)

The characteristic x rays can be used as powerful analytical tools for qualitative and quantitative determination of the major, minor and trace composition of materials. X Ray Fluorescence (XRF) techniques used for almost four decade to solve many problem...

G. E. Gigante A. L. Hanson

1990-01-01

104

Mitigation of fluorescence and scattering in reflection convex-crystal X-ray spectrometers  

NASA Astrophysics Data System (ADS)

X-ray diagnostics in today's high-energy density environments must contend with intense and energetic X-ray background levels. In this work, we address the issues of X-ray fluorescence and scattering in reflection-geometry X-ray crystal spectrometers. In this geometry, the detector can capture not only a dispersed X-ray spectrum but also fluorescence and/or scattered X-rays from the diffracting crystal and crystal mounts. Studies to optimally reduce these sources of spectral contamination have been performed using the HENEX spectrometer. Variables that mitigate such unwanted background include filtration, collimation and judicious selection of crystal and detector materials.

Szabó, C. I.; Hudson, L. T.; Henins, A.; Holland, G. E.; Atkin, R.; Seely, J. F.

2006-11-01

105

Determination of beryllium by using X-ray fluorescence spectrometry.  

PubMed

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

Zawisza, Beata

2008-02-02

106

Monte Carlo Modeling of Generation of Characteristic, Continuous and Fluorescent X-rays by Electron Impact  

NASA Astrophysics Data System (ADS)

A Monte Carlo (MC) simulation to calculate the absolute intensity of an X-ray spectrum generated by electron impact was developed. The X-ray spectrum consists of continuous and characteristic X-rays excited by primary electron, and fluorescent X-rays due to the absorption of the continuous and characteristic X-rays. The comparison of the simulated X-ray spectra with the experimental ones showed excellent agreement for bulk Al, Sc, Ge and Zr. The quantitative investigations of the simulated intensity of the characteristic K peak and the effect of the fluorescent X-ray were performed. It was confirmed that the developed MC simulation is applicable not only for optimizing the design of the rotor-type X-ray source to develop a high-brightness wavelength-tunable X-ray source, but also for quantitative electron probe microanalysis.

Nagatomi, Takaharu; Hibi, Takaaki; Takai, Yoshizo; Obori, Ken-ichi; Awata, Syogo; Yurugi, Toshikazu

2003-10-01

107

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

Microsoft Academic Search

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)

Syed F. Naeem; Khalid Chouffani; Douglas P. Wells

2009-01-01

108

The X-ray Fluorescence Microscopy Beamline at the Australian Synchrotron  

SciTech Connect

A hard x-ray micro-nanoprobe has commenced operation at the Australian Synchrotron providing versatile x-ray fluorescence microscopy across an incident energy range from 4 to 25 keV. Two x-ray probes are used to collect {mu}-XRF and {mu}-XANES for elemental and chemical microanalysis: a Kirkpatrick-Baez mirror microprobe for micron resolution studies and a Fresnel zone plate nanoprobe capable of 60-nm resolution. Some unique aspects of the beamline design and operation are discussed. An advanced energy dispersive x-ray fluorescence detection scheme named Maia has been developed for the beamline, which enables ultrafast x-ray fluorescence microscopy.

Paterson, D.; Jonge, M. D. de; Howard, D. L.; Lewis, W.; McKinlay, J.; Starritt, A.; Kusel, M. [Australian Synchrotron, Clayton, VIC 3168 (Australia); Ryan, C. G.; Kirkham, R.; Moorhead, G. [CSIRO, Clayton VIC, 3168 (Australia); Siddons, D. P. [Instrumentation Division, Brookhaven National Laboratory, Brookhaven, NY (United States)

2011-09-09

109

The X-ray Fluorescence Microscopy Beamline at the Australian Synchrotron  

NASA Astrophysics Data System (ADS)

A hard x-ray micro-nanoprobe has commenced operation at the Australian Synchrotron providing versatile x-ray fluorescence microscopy across an incident energy range from 4 to 25 keV. Two x-ray probes are used to collect ?-XRF and ?-XANES for elemental and chemical microanalysis: a Kirkpatrick-Baez mirror microprobe for micron resolution studies and a Fresnel zone plate nanoprobe capable of 60-nm resolution. Some unique aspects of the beamline design and operation are discussed. An advanced energy dispersive x-ray fluorescence detection scheme named Maia has been developed for the beamline, which enables ultrafast x-ray fluorescence microscopy.

Paterson, D.; de Jonge, M. D.; Howard, D. L.; Lewis, W.; McKinlay, J.; Starritt, A.; Kusel, M.; Ryan, C. G.; Kirkham, R.; Moorhead, G.; Siddons, D. P.

2011-09-01

110

Structure elucidation of laser dye coumarin-540A by joint application of X-ray diffraction, X-ray fluorescence, prompt fluorescence, UV and visible spectroscopy  

Microsoft Academic Search

X-ray, ultraviolet, and visible light induced photophysical changes of coumarin-540A in ethanol have been studied by the joint applications of X-ray, ultraviolet, and visible spectroscopy. Some impurities were found by X-ray fluorescence measurements. During the high power optical pumping, coumarin showed photochemical changes. Photoproduct emission spectra characteristics showed that photoproduct molecules can also be used as a laser dye at

Sinan S. Keskin; Necdet Aslan; Fuat Bayrakçeken

2007-01-01

111

Structure elucidation of laser-dye coumarin-540A by joint application of X-ray diffraction, X-ray fluorescence, prompt fluorescence, UV and visible spectroscopy  

Microsoft Academic Search

X-ray, ultraviolet, and visible light induced photophysical changes of coumarin-540A in ethanol has been studied by the joint applications of X-ray, ultraviolet, and visible spectroscopy. Some impurities were found by X-ray fluorescence measurements. During the high power optical pumping, coumarin showed photochemical changes. Photoproduct emission spectra characteristics showed that photoproduct molecules could also be used as a laser-dye at a

Sinan S. Keskin; Necdet Aslan; Fuat Bayrakçeken

2007-01-01

112

Human thyroid specimen imaging by fluorescent x-ray computed tomography with synchrotron radiation  

NASA Astrophysics Data System (ADS)

Fluorescent x-ray computed tomography (FXCT) is being developed to detect non-radioactive contrast materials in living specimens. The FXCT system consists of a silicon (111) channel cut monochromator, an x-ray slit and a collimator for fluorescent x ray detection, a scanning table for the target organ and an x-ray detector for fluorescent x-ray and transmission x-ray. To reduce Compton scattering overlapped on the fluorescent K(alpha) line, incident monochromatic x-ray was set at 37 keV. The FXCT clearly imaged a human thyroid gland and iodine content was estimated quantitatively. In a case of hyperthyroidism, the two-dimensional distribution of iodine content was not uniform, and thyroid cancer had a small amount of iodine. FXCT can be used to detect iodine within thyroid gland quantitatively and to delineate its distribution.

Takeda, Tohoru; Yu, Quanwen; Yashiro, Toru; Yuasa, Tetsuya; Hasegawa, Yasuo; Itai, Yuji; Akatsuka, Takao

1999-09-01

113

Measurement and calculation of escape peak intensities in synchrotron radiation X-ray fluorescence analysis  

NASA Astrophysics Data System (ADS)

In synchrotron radiation X-ray fluorescence experiments, the escape peaks, generating from the Si(Li) solid detector, can disrupt seriously the quantitative and qualitative analysis. In this paper, 14 specimens, such as metals, compounds and plants, have been chosen as objectives to determine the intensities and positions of escape peaks. In all, the characteristic X-ray fluorescence peaks and their escape peaks of 12 elements have been measured. Comparing the experimental values with the standard values, the escape peaks can be discriminated. To calculate the ratios of intensities of the escape peaks and their corresponding characteristic X-ray fluorescence peaks, a simplified Si K/? emergent spherical distribution has been put forward. It is found that the experimental results are in accordance with that of calculation, i.e. both the experimental and theoretical ratios decrease from 1% to 0.1% with the increasing atomic number from 18 to 33 (from 1 to 9 keV in X-ray range).

Kang, S. X.; Sun, X.; Ju, X.; Huang, Y. Y.; Yao, K.; Wu, Z. Q.; Xian, D. C.

2002-06-01

114

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

PubMed

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. PMID:23635242

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

2013-04-01

115

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

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

116

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

Microsoft Academic Search

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)

Syed F. Naeem; Khalid Chouffani; Douglas P. Wells

2009-01-01

117

Determination of water content in silica nanopowder using wavelength-dispersive X-ray fluorescence spectrometer  

Microsoft Academic Search

A wavelength-dispersive X-ray fluorescence (WDXRF) technique that uses the scattered radiation of the X-ray tube lines and the fluorescence radiation of an element present in a powder sample is proposed as a non-destructive method for the determination of the water content in silica powder. Although direct X-ray fluorescence analysis of water using WDXRF is not adequate for the quantitative determination

Yong Suk Choi; Jong-Yun Kim; Suk Bon Yoon; Kyuseok Song; Young Jin Kim

2011-01-01

118

Comparative studies of X-ray images and fluorescence images of the same specimens  

NASA Astrophysics Data System (ADS)

A flash contact soft x-ray microscope using laser-induced plasma as a flash x-ray source is a practical instrument for observation of living organisms in water [1-4]. As previously reported we developed a tabletop flash contact soft x-ray microscope System [3]. In this System, x-ray images are given as whole projection of the specimens on the PMMA membrane. This causes us some complexity for understanding the x-ray images. It is necessary to attribute features in the x-ray images to sub-cellular structures of the specimen. For this purpose we have developed a new sample holder, where specimens are observable with a fluorescence microscope just before x-ray exposure. Fluorescence images of onion epidermal cells stained by DAPI and x-ray images of the same specimens are compared.

Majima, T.; Tomie, T.; Shimizu, H.

2003-03-01

119

Fluorescence X-ray micro-spectroscopy activities at ESRF  

NASA Astrophysics Data System (ADS)

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.

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

120

Using X-ray Fluorescence to Date Petroglyphs  

NASA Astrophysics Data System (ADS)

Petroglyphs were created by ancient peoples of the Colorado Plateau who pecked figures of cultural or religious significance into the desert varnish, the ubiquitous dark patina covering the rock surfaces of the region. Manganese (Mn) is a significant elemental component of desert varnish that is often at trace levels in the substrate rock. As such, F. Lytle has shown that under certain conditions, it may be possible to estimate the age of petroglpyhs using Mn levels. In this work we use x-ray fluorescence to measure Mn levels in the desert varnish of petroglyphs and then use dated graffiti to attempt to calibrate the Mn level with age. Preliminary results from petroglyph panels in eastern Utah will be presented.

McNeil, James

2009-10-01

121

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

SciTech Connect

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.

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

2002-01-01

122

Application of synchrotron radiation to x-ray fluorescence analysis of trace elements  

SciTech Connect

The development of synchrotron radiation x-ray sources has provided the means to greatly extend the capabilities of x-ray fluorescence analysis for determinations of trace element concentrations. A brief description of synchrotron radiation properties provides a background for a discussion of the improved detection limits compared to existing x-ray fluorescence techniques. Calculated detection limits for x-ray microprobes with micrometer spatial resolutions are described and compared with experimental results beginning to appear from a number of laboratories. The current activities and future plans for a dedicated x-ray microprobe beam line at the National Synchrotron Light Source (NSLS) of Brookhaven National Laboratory are presented.

Gordon, B.M.; Jones, K.W.; Hanson, A.L.

1986-08-01

123

Full-field x-ray fluorescence imaging microscope with a Wolter mirror  

Microsoft Academic Search

Full-field x-ray fluorescence (XRF) and transmission x-ray microscopic images were obtained with a Wolter-type mirror (10× magnification). A synchrotron radiation white beam (4-20 keV) from a bending magnet beamline at the Photon Factory was used to obtain XRF images and a conventional laboratory x-ray source (8.04 keV) was used to obtain transmission x-ray images. The effects of the coherent and

Akihisa Takeuchi; Sadao Aoki; Kimitake Yamamoto; Hidekazu Takano; Norio Watanabe; Masami Ando

2000-01-01

124

Cosputtered composition-spread reproducibility established by high-throughput x-ray fluorescence  

SciTech Connect

We describe the characterization of sputtered yttria-zirconia composition spread thin films by x-ray fluorescence (XRF). We also discuss our automated analysis of the XRF data, which was collected in a high throughput experiment at the Cornell High Energy Synchrotron Source. The results indicate that both the composition reproducibility of the library deposition and the composition measurements have a precision of better than 1 atomic percent.

Gregoire, John M.; Dale, Darren; Kazimirov, Alexander; DiSalvo, Francis J.; Dover, R. Bruce van [Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853 (United States); Cornell High Energy Synchrotron Source, Cornell University, Ithaca, New York 14853 (United States); Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853 (United States); Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853 (United States)

2010-09-15

125

Fluorescent x-ray computed tomography with synchrotron radiation using fan collimator  

Microsoft Academic Search

We describe a new system of fluorescent x-ray computed tomography applied to image nonradioactive contrast materials in vivo. The system operates on the basis of computed tomography (CT) of the first generation. The experiment was also simulated using the Monte Carlo method. The research was carried out at the BLNE-5A bending-magnet beam line of the Tristan Accumulation Ring in Kek,

Tohoru Takeda; Masahiro Akiba; Tetsuya Yuasa; Masahiro Kazama; Atunori Hoshino; Yuuki Watanabe; Kazuyuki Hyodo; F. Avraham Dilmanian; Takao Akatsuka; Yuji Itai

1996-01-01

126

Parametric down conversion of X-rays, recent experiments  

NASA Astrophysics Data System (ADS)

Parametric down conversion of X-ray photons in diamond crystals was detected in six experiments, all using the phase matching scheme first employed in the X-ray regime by Eisenberger and McCall (Eisenberger and McCall, Phys. Rev. Lett. 26 (1971) 684). The conversion events were detected by a combination of time correlation spectroscopy and energy discrimination. The time correlation spectra gave a direct comparison of the conversion rate over the accidental coincidence rate.

Adams, B.; Nishino, Y.; Novikov, D. V.; Materlik, G.; Mills, D. M.

2001-07-01

127

[Measurement and analysis of lead in soil using X-ray fluorescence spectroscopy].  

PubMed

The present paper analyzed the characteristics of X-ray fluorescence spectroscopy (XRF) of metal element lead in soil using the NITON XLt793 portable X-ray fluorescence spectra of heavy metal analyzer under laboratory conditions. The characteristic spectral lines of L(alpha) (energy: 10. 55 keV) and L(beta) (energy: 12. 61 keV) with different matrix elements were selected respectively for lead in the experiment. By measuring the intensities of the characteristic spectral line with different Pb concentration, the results demonstrate that the relation between concentration [mass fraction 10 x 10(-6) - 1 800 x 10(-6)] of Pb element and the intensity of the characteristic spectrum is well linear. The calibration curve of Pb was plotted based on the different concentration measurement results, and the limit of detection of 7.89 x 10(-6) was obtained for Pb in soil. PMID:23697153

Zhang, Rong; Zhang, Yu-Jun; Zhang, Wei; Chen, Dong; Yu, Xiao-Ya; Gao, Yan-Wei

2013-02-01

128

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

DOEpatents

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.

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

129

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

SciTech Connect

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.

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

130

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

Microsoft Academic Search

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

Lee Grodzins; John Niland

2002-01-01

131

X-ray fluorescence hologram data collection with a cooled avalanche photodiode  

Microsoft Academic Search

A high counting rate X-ray detector with an appropriate energy resolution is desired for high quality X-ray fluorescence hologram measurements because a holographic pattern is detected as extremely small intensity variations of X-ray fluorescence on a large intensity background. A cooled avalanche photodiode (APD), which has about 10% energy resolution and is designed for a high counting rate, fits the

Kouichi Hayashi; Yukio Takahashi; Ei-Ichiro Matsubara; Shunji Kishimoto; Takeharu Mori; Masahiko Tanaka

2002-01-01

132

X-ray microbeam fluorescence and strain measurements during electromigration  

NASA Astrophysics Data System (ADS)

Electromigration, atom diffusion caused by an electric current, has long been a matter of concern to the microelectronic industry because it causes failures in thin film interconnects. In industrial practice, a small amount of Cu (0.25 at.%-2 at.%) is alloyed into Al interconnects since Cu is found to inhibit the failure in interconnects caused by electromigration. The beneficial effect of Cu is not fully understood. The available evidence suggests that the Cu is usually swept away from an area by electromigration before fast Al diffusion leads to appreciable damage in the interconnect. Since grain boundary diffusion is the dominant diffusion mechanism at the relatively low temperatures at which most microelectronic devices are used, and since Cu has very low solid solubility in Al at operating temperatures, Cu segregated into the grain boundaries must reduce the electromigration flux of Al along these dominant paths in order to produce the observed electromigration lifetime improvement. Because of the critical role of Cu in Al(Cu), it is essential to obtain information on the motion and distribution of solute Cu atoms during electromigration. The goal of this research was to obtain for the first time, simultaneously and in real time, spatially resolved information on chemical composition and equal-biaxial stress in polycrystalline Al(Cu) thin film interconnects during electromigration testing. Polychromatic x-ray microbeams from a synchrotron were used. A novel x-ray microbeam instrumentation, developed for this purpose, uses tapered glass capillaries to obtain micron-scale spatial resolution. Two energy dispersive solid state detectors were used to measure simultaneously both solute Cu composition and local strain. Results of Cu concentration mapping showed that the solute Cu concentration as dilute as 500 PPM in the SiO2 passivated Al(Cu) interconnects could be detected through Cu K, fluorescence generated by the incident white x-ray. Time evolution of solute Cu composition in the 200 mum-long, 10 mum-wide, 0.5 mum-thick passivated Al(Cu) conductor lines were measured for several electromigration testing conditions, and the evolution profiles could be simulated based on the proposed one dimensional continuum model with phenomenological flux equations and a finite difference calculation method. From the steady state profile, the apparent: effective charge Z*Cu of Cu in Al(Cu) was determined to be -8.6 +/- 0.6. The evolution of Cu concentration profiles could be manipulated by controlling the direction and magnitude of the current flow at different temperatures. The effective grain boundary diflusivity D DeffCu was determined by fitting the time dependent experimental Cu concentration profiles. The results show Arrhenius behavior of DeffCu=Doexp -QkT for T = 275°C-325°C with Do = 10-(2.3 +/- 1.6) cm2/sec and Q = 0.76 +/- 0.19 eV. Real-time electromigration-induced strains normal to the sample surface, monitored by x-ray microbeam diffraction, showed that linear strain profile developed within 60% of the conductor line from the cathode end after about 9 hrs of electromigration with 1.5 x 105 A/cm 2 at 300°C. This corresponds to 3MPa/mum equibiaxial stress. From the Cu profile measured at the same time, the critical Cu concentration for significantly slowing down Al grain boundary diffusion is estimated to be ˜0.15 at.%. These data also confirm that downstream Cu transport is accompanied by a counter flow of Al in the upstream direction.

Kao, Hsien-Kang (Michael)

2000-10-01

133

Description of CORSET: a computer program for quantitative x-ray fluorescence analysis  

Microsoft Academic Search

Quantitative x-ray fluorescence analysis requires a method of correcting for absorption and secondary fluorescence effects due to the sample matrix. The computer program CORSET carries out these corrections without requiring a knowledge of the spectral distribution of the x-ray source, and only requires one standard per element or one standard containing all the elements. Sandia's version of CORSET has been

Stohl

1980-01-01

134

Dendrimer-folate-copper conjugates as bioprobes for synchrotron X-ray fluorescence imaging.  

PubMed

We present a bioprobe for synchrotron X-ray fluorescence imaging based on dendrimer-folate-copper conjugates. The metal nanoclusters within a dendrimer exhibit excellent FR-targeting properties in KB cells. It could be used as a new multifunction bioprobe for synchrotron X-ray fluorescence mapping. PMID:24072098

Zhang, Yuanqing; Xu, Xiaoping; Wang, Lu; Lin, Jun; Zhu, Ying; Guo, Zhi; Sun, Yanhong; Wang, Hua; Zhao, Yun; Tai, Renzhong; Yu, Xiaohan; Fan, Chunhai; Huang, Qing

2013-10-10

135

In vivo X-ray fluorescence of lead in bone using K X-ray excitation with 109Cd sources: Radiation dosimetry studies  

Microsoft Academic Search

Independent experiments have been performed at two centers, to evaluate the dosimetric properties of their respective š°⁚Cd K X-ray fluorescence (XRF) bone lead measurement systems. Measurements were made of the dose to several points on the skin of the lower leg, at the surface of the tibia, in the red marrow tibia cavity, at the midcalf, and in the abdominal

A. C. Todd; F. E. McNeill; J. E. Palethorpe; D. E. Peach; D. R. Chettle; M. J. Tobin; S. J. Strosko; J. C. Rosen

1992-01-01

136

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

NASA Astrophysics Data System (ADS)

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.

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

2005-07-01

137

Portable x-ray fluorescence spectrometer. Innovative technology summary report  

SciTech Connect

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.

NONE

1998-12-01

138

High-throughput screening with micro-x-ray fluorescence  

NASA Astrophysics Data System (ADS)

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.

Havrilla, George J.; Miller, Thomasin C.

2005-06-01

139

X-ray Fluorescence Spectrometry with the SELENE Orbiter  

NASA Astrophysics Data System (ADS)

X-ray fluorescence spectrometry of the Moon using a CCD-based instrument ``XRS'' is planned with the SELENE (Selenological and Engineering Explorer) orbiter, which will be launched in 2003. In the Apollo 15 and 16 missions, elemental mapping of Mg, Al and Si has been performed at the lunar equatorial regions for only 9% of the total surface. Much improved datasets will be obtained by using the XRS to map most of major elements, for 90 % coverage of the total surface, and within 20 km spatial resolution. Key scientific objectives are (a) to measure the global average of lunar surface composition for investigation of the overall properties of lunar crust, (b) to map the rock-type distribution to study the formation and evolution of the crust and the maria, and to speculate the origin of the dichotomy, (c) to survey the chemical pattern of lava flows, or bottoms of craters or basins, for surveying the vertical structure and composition of the lunar crust and mantle. We describe the XRS instrument.

Okada, Tatsuaki; Kato, Manabu; Fujimura, Akio; Tsunemi, Hiroshi; Kitamoto, Shunji

1999-01-01

140

Recovering Ancient Inscriptions by X-ray Fluorescence Imaging  

NASA Astrophysics Data System (ADS)

For many ancient cultures including those of the Mediterranean, carved stone inscriptions provide our most detailed historical record. Over the ages the surfaces of many of these inscriptions have been eroded so that the original text can no longer be distinguished. A method that allowed at least partial recovery of this lost text would provide a major breakthrough for the study of these cultures. The scope of analytical techniques that can be applied to stone tablets is limited by their large size and weight. We have applied X-ray fluorescence imaging to study the text of ancient stone inscriptions [1]. This method allows the concentrations of trace elements, including those introduced during inscription and painting, to be measured and mapped. The images created in this way correspond exactly to the published text of the inscription, both when traces of letters are visible with the naked eye and when they are barely detectable. [1] J. Powers et al., Zeitschrift für Papyrologie und Epigraphik 152: 221-227 (2005).

Powers, Judson; Dimitrova, Nora; Huang, Rong; Smilgies, Detlef-M.; Bilderback, Don; Clinton, Kevin; Thorne, Robert

2006-03-01

141

Energy-dispersive X-ray fluorescence analysis with pyrographite crystals and small X-ray tubes  

Microsoft Academic Search

The advantages and peculiarities are described of energy-dispersive X-ray fluorescence analysis with preliminary energy selection\\u000a of the radiation coming from a sample with the help of a cylindrical system of pyrographite crystals. The results of application\\u000a of this method to the analysis of U and transuranium elements in the solutions of spent nuclear fuel reprocessing are presented.\\u000a Minimum detectable concentration

V. V. Berdikov; O. I. Grigor'ev; B. S. Iokhin

1980-01-01

142

X-ray fluorescence and energy dispersive x-ray diffraction for the quantification of elemental concentrations in breast tissue  

Microsoft Academic Search

This paper presents improvements on a previously reported method for the measurement of elements in breast tissue specimens (Geraki et al 2002 Phys. Med. Biol. 47 2327-39). A synchrotron-based system was used for the detection of the x-ray fluorescence (XRF) emitted from iron, copper, zinc and potassium in breast tissue specimens, healthy and cancerous. Calibration models resulting from the irradiation

K. Geraki; M. J. Farquharson; D. A. Bradley

2004-01-01

143

X-ray fluorescence and energy dispersive x-ray diffraction for the quantification of elemental concentrations in breast tissue  

Microsoft Academic Search

This paper presents improvements on a previously reported method for the measurement of elements in breast tissue specimens (Geraki et al 2002 Phys. Med. Biol.47 2327–39). A synchrotron-based system was used for the detection of the x-ray fluorescence (XRF) emitted from iron, copper, zinc and potassium in breast tissue specimens, healthy and cancerous. Calibration models resulting from the irradiation of

K Geraki; M J Farquharson; D A Bradley

2004-01-01

144

Resonant Inelastic X-Ray Scattering in Hexagonal Boron Nitride Observed by Soft-X-Ray Fluorescence Spectroscopy  

Microsoft Academic Search

Photon-excited B K fluorescence spectra were measured for hexagonal boron nitride using tunable synchrotron radiation below and above the B K edge. We report Raman-like resonant inelastic scattering of soft x rays involving excitation of delocalized valence-band electrons. The inelastic scattering features track with the excitation energy below threshold, go through a resonance as the excitation is tuned to the

J. J. Jia; T. A. Callcott; Eric L. Shirley; J. A. Carlisle; L. J. Terminello; A. Asfaw; D. L. Ederer; F. J. Himpsel; R. C. C. Perera

1996-01-01

145

Resonant inelastic x-ray scattering in hexagonal boron nitride observed by soft-x-ray fluorescence spectroscopy  

Microsoft Academic Search

Photon-excited B {ital K} fluorescence spectra were measured for hexagonal boron nitride using tunable synchrotron radiation below and above the B {ital K} edge. We report Raman-like resonant inelastic scattering of soft x rays involving excitation of delocalized valence-band electrons. The inelastic scattering features track with the excitation energy below threshold, go through a resonance as the excitation is tuned

J. J. Jia; T. A. Callcott; Eric Shirley; J. A. Carlisle; L. J. Terminello; A. Asfaw; D. L. Ederer; F. J. Himpsel; R. C. Perera

1996-01-01

146

Characterization and applications of a new tabletop confocal micro X-ray fluorescence setup  

NASA Astrophysics Data System (ADS)

A tabletop confocal three-dimensional micro X-ray fluorescence (3D micro-XRF) setup was designed, based on polycapillary X-ray optics and a micro-focus X-ray source. This confocal setup consists of a polycapillary full lens to focus the incident beam and a polycapillary half lens to collect the X-ray fluorescence. The confocal volume was proved to be ellipsoidal. The full-width at half maximum (FWHM) of the confocal volume in three directions were measured with a “knife edge” scan method to obtain the spatial resolution of the confocal setup. The structure of multilayer samples was studied using the depth scan technique.

Lin, Xiaoyan; Wang, Zhihong; Sun, Tianxi; Pan, Qiuli; Ding, Xunliang

2008-06-01

147

Theory and analysis of soft x-ray laser experiments  

SciTech Connect

The atomic modeling of soft x-ray laser schemes presents a formidable challenge to the theorists - a challenge magnified by the recent successful experiments. A complex plasma environment with many ion species present must be simulated. Effects such as turbulence, time dependence, and radiation transport, which are very difficult to model accurately, may be important. We shall describe our efforts to model the recently demonstrated soft x-ray laser in collisionally pumped neon-like selenium, with emphasis on the ionization balance and excited state kinetics. The relative importance of various atomic processes, such as collisional excitation and dielectronic recombination, on the inversion kinetics will be demonstrated. We shall compare our models with experimental results and evaluate the success of this technique in predicting and analyzing the results of x-ray laser experiments. 22 refs., 5 figs., 3 tabs.

Whitten, B.L.; Hazi, A.U.

1985-10-01

148

Mirror-based x-ray fluorescence microprobes at the Advanced Photon Source and the National Synchrotron Light Source  

Microsoft Academic Search

High-energy synchrotrons are valuable sources of highly collimated, intense X-ray radiation for use in X-ray microprobe analysis including trace element quantification (X-ray fluorescence), chemical speciation determinations (X-ray absorption fine structure spectroscopy) and phase identification (X-ray diffraction). Kirkpatrick-Baez mirrors are being increasingly utilized for production of X-ray microbeams (~ ľm) because of their achromaticity, photon density gains in excess of 104,

S. R. Sutton; M. Newville; M. Rivers; A. Lanzirotti

2006-01-01

149

UCSD high energy X-ray timing experiment  

NASA Astrophysics Data System (ADS)

The High Energy X-Ray Timing Experiment (HEXTE) is one of three X-ray instrument components on NASA's X-Ray Timing Explorer (XTE) mission to be launched in 1994 for the detailed 2-200 keV study of bright X-ray pulsars and other X-ray sources through observations of their temporal variability. The XTE will directly address issues pertaining to the nature of compact matter (white dwarfs to massive black holes), the evolution of systems containing these objects, and the conditions of astrophysical plasmas in their vicinity under extreme conditions of gravity, magnetic fields, and temperatures. The HEXTE is composed of two clusters, each containing four Nal/CsI phoswich scintillation counters with a total net collecting area of 800 sq cm per cluster. The detector system is designed to achieve state-of-the-art scintillator energy resolution (Delta E/E not above 0.1 at 100 keV) and high spectral sensitivity (3 sigma detection of 1 milliCrab active galaxy in one energy resolution element, Delta E = 20 keV, at 100 keV in 100,000 sec).

Rothschild, Richard E.; Pelling, Michael R.; Gruber, Duane E.; Matteson, James L.

1989-11-01

150

Angular Distribution of Fluorescent L X-Rays and Compton-Scattering Photons  

Microsoft Academic Search

The angular distribution of fluorescent L X-rays and Compton-scattering photons was investigated by measuring differential cross sections for high–atomic-number elements. The measurements were taken simultaneously for L X-ray and Compton-scattering photons using Am-241 radioisotope as photon sources and a Si(Li) detector in various emission angles. The measurements confirm well-known angular dependency of the Compton-scattering differential cross section. L X-ray angular

I. Han; L. Demir

2011-01-01

151

A low background X-ray fluorescence system for microsphere quantitation  

Microsoft Academic Search

An automated low background x-ray fluorescence detection system was developed for measuring blood flow rates by the microsphere technique. An x-ray beam was polarized to lower Compton scattering. A Si(Li) detector was used for efficient characteristic x-ray detection with preferentially decreased sensitivity for Compton scattering, a CaFâ scintillation detector was engaged in the anti-coincidence method to lower the background, and

Y. Morita; K. E. Hosier; V. Lorenz; L. Kaufman; H. Mori; J. E. Hoffman

1988-01-01

152

Quantitative x-ray fluorescence analysis using monochromatic synchrotron radiation  

SciTech Connect

The use of high-intensity, tunable monochromatic x-rays for the quantitative analysis of biological and geochemical specimens at the 10/sup -8/ g level is described. Incident x-rays were obtained from the new LBL-EXXON permanent magnet wiggler beamline at the Stanford Synchrotron Radiation Laboratory. The sample detector geometry was designed to make optimal use of polarization advantages for background reduction. Questions regarding the sensitivity and accuracy of the measurements were studied with particular emphasis on the advantages of tuning the x-ray energies for optimum excitation for specific elements. The implications of these measurements with respect to the use of x-ray microprobe beams will be discussed.

Jaklevic, J.M.; Giauque, R.D.; Thompson, A.C.

1984-09-01

153

Effect of x-ray beamline optics on x-ray photon correlation spectroscopy experiments.  

SciTech Connect

We have evaluated the applicability of vertically-focusing kinoform lenses for tailoring the vertical coherence length of storage-ring undulator x-ray beams so that the entirety of the coherent flux can be used for small angle multi-speckle x-ray photon correlation spectroscopy (XPCS) experiments. We find that the focused beam produced by a kinoform lens preserves the coherence of the incident unfocused beam and that at an appropriate distance downstream of the focus, the diverging beam produces speckles nearly identical to those produced by an equivalently-sized unfocused beam. We have also investigated the effect of imperfect beamline optics on the observed coherence properties of the beam. Via phase contrast imaging and beam-divergence measurements, we find that a horizontally-deflecting mirror in our beamline precludes us from seeing the true radiation source point but instead acts as an apparent source of fixed size at the center of our insertion device straight section. Finally, we discuss how expected near-future optimization of these optics will greatly benefit XPCS measurements performed at beamline 8-ID-I at the Advanced Photon Source.

Sandy, A. R.; Evans-Lutterodt, K.; Fezzaa, K.; Kim, S.; Narayanan, S.; Sprung, M.; Stein, A.; X-Ray Science Division; BNL; Gwangiu Inst. of Science and Technology

2007-01-01

154

(X-ray diffraction experiments with condenser matter)  

SciTech Connect

This report discusses research on the following topics: high-{Tc} superconductors; The response of crystal to an applied electric field; quasicrystals; surface structure and kinetics of surface layer formation; EXAFS studies of superconductors and heterostructures; effect of iron on the crystal structure of perovskite; x-ray detector development; and SAXS experiments. (LSP)

Coppens, P.

1990-01-01

155

X-Ray Astronomy Discovery Experiments*  

NASA Astrophysics Data System (ADS)

A Lockheed proposal to ``scan along the galactic equator in the direction of the galactic center '' ^1 was made to NASA in late 1960, over a year before Giacconi's discovery of Sco X-1, in 1962.^2 The nature of the Lockheed survey and first results were announced in 1964. Data in several publications verified the 1960 postulate that the brightest sources would lie within the galaxy and at low galactic latitude. A fourth publication summarized results.^3 A recent listing ^4 confirmed the discovery nature of the nearly fifty-year-old Lockheed proposal, and the effort's success. Data from the two concurrent experiments will be presented, and several published or just copyrighted appraisals of the two efforts will be described. *Work supported by NASA contracts NAS5-1174 and NASw-909, the Lockheed Independent Research Program, and several successive forms of Ruffner Associates. ^1P. C. Fisher, Lockheed Missiles and Space Division Document LMSD 702172, Palo Alto, (1960) ^2R. Giacconi et al., Phys. Rev. Lett. 9 (1962) 439 ^3P. C. Fisher et al., Astrophys. J., 151 (1968) 1. ^4P. C. Fisher, Who'sWho in the World, Marquis Who's Who LLC, New Providence, NJ, 22^nd Edition, (2005) 667-668.

Fisher, P. C.

2008-04-01

156

The progress of X-ray fluorescence computed tomography at SSRF  

NASA Astrophysics Data System (ADS)

X-ray fluorescence computed tomography is a stimulated emission tomography that allows nondestructive reconstruction of elements distribution in the sample and has been applied in many fields. Since 2007 we have developed X-ray fluorescence tomography for microanalysis. In 2010, the system was established at the Shanghai Synchrotron Radiation Facility (SSRF) and preliminary experimental results were obtained at the X-ray imaging (BL13W1) and hard X-ray micro-focusing beamline (BL15U1). Recently, an ordered-subsets expectation maximization algorithm has been introduced to speed up the data acquisition process. We are now studying accelerating X-ray fluorescence computed tomography based fast scanning and the new algorithm.

Deng, Biao; Yang, Qun; Du, Guohao; Tong, Yajun; Xie, Honglan; Xiao, Tiqiao

2013-06-01

157

X-ray fluorescence analyzers for investigating postmediaeval pottery from Southern Moravia.  

PubMed

This paper deals with an investigation of ceramic archaeological finds with the use of in-situ X-ray fluorescence analysis. Firstly, three configurations of X-ray fluorescence analyzers constructed and used at the Czech Technical University in Prague are described and compared for use in a non-destructive survey of siliceous materials. Detection limits, depth of analysis, the relation of the analyzed area, the homogeneity of the samples, and variations in the element concentrations are discussed. Secondly, many shards of postmediaeval pottery from Southern Moravia are analyzed with X-ray fluorescence analysis and some of them also with electron microprobe analysis. Selected results are described. PMID:19914840

Trojek, Tomás; Hlozek, Matin; Cechák, Tomás; Musílek, Ladislav

2009-10-25

158

Hyper-filter-fluorescer spectrometer for fusion x-ray diagnostics  

SciTech Connect

The filter-fluorescer spectrometer (FFS) is a powerful tool for measuring x-ray spectrum from high fluence x-ray sources. However, this technique is limited to energies less than 120 keV, because there are no practical absorption edges available above this energy. In this paper, we present a new method of utilizing the filter-fluorescer system for x-ray spectral measurement above 120 keV. The new apparatus is called hyper-filter-fluorescer spectrometer (HFFS).

Wang, C.L.

1981-06-16

159

X-ray fluorescence measurements of the surface elemental composition of asteroid 433 Eros  

Microsoft Academic Search

We report major element ratios determined for the S-class asteroid 433 Eros using remote-sensing x-ray fluorescence spectroscopy with the near-Earth asteroid rendezvous Shoemaker x-ray spectrometer (XRS). Data analysis techniques and systematic errors are described in detail. Data acquired during five solar flares and during two extended \\

L. R. Nittler; R. D. Starr; L. Lim; T. J. McCoy; T. H. Burbine; R. C. Reedy; Jacob I. Trombka; Paul Gorenstein; S. W. Squyres; William V. Boynton; T. P. McClanahan; J. S. Bhangoo; P. E. Clark; M. E. Murphy; Rosemary Killen

2001-01-01

160

Hyper-Filter-Fluorescer Spectrometer for Fusion X-Ray Diagnostics.  

National Technical Information Service (NTIS)

The filter-fluorescer spectrometer (FFS) is a powerful tool for measuring x-ray spectrum from high fluence x-ray sources. However, this technique is limited to energies less than 120 keV, because there are no practical absorption edges available above thi...

C. L. Wang

1981-01-01

161

Critical review of high gain x-ray FEL experiments  

SciTech Connect

There is a renewed interest at the present time to develop x-ray free electron lasers (FELs). The interest is driven by the scientific opportunities with coherent x-rays glimpsed at the third generation light sources. With the recent development in linac technology in producing high-energy, high-brightness electron beams, it is now possible to design intense coherent x-ray source for wavelengths as short as one Angstrom based on the self- amplified spontaneous emission (SASE) principle. Major linac laboratories such as SLAC and DESY are therefore actively pursuing detailed design studies for the x-ray SASE facilities. The x-rays from these facilities will provide a peak brightness more than ten orders of magnitude higher than that of the current synchrotron radiation sources. Short wavelength coherent radiation could also be generated with harmonic generation techniques in linacs or storage rings. However, these schemes are not expected to be effective for 1 {Angstrom} wavelengths. This review will therefore concentrate on the linac based SASE scheme. The critical components of the SASE are: an electron source consisting of an RF photocathode gun with the emittance corrector producing high brightness electron beam; the beam bunching and acceleration; and a long undulator in which the radiation develops from initially incoherent radiation to intense, coherent radiation. We discuss the critical experimental issues in these components highlighting some relevant recent experiments. We also discuss issues related to the SASE experiment which are distinct from the usual free electron lasers. We give a brief survey of the world-wide SASE experiments. We conclude with a summary and outlook.

Kim, Kwang-Je

1996-08-01

162

Synchrotron radiation based micro X-ray fluorescence analysis of the calibration samples used in surface sensitive total reflection and grazing emission X-ray fluorescence techniques  

NASA Astrophysics Data System (ADS)

Total reflection X-ray fluorescence (TXRF) and grazing emission X-ray fluorescence (GEXRF) are surface sensitive techniques and can be used for detailed surface studies of different materials, including ultra-low concentration contamination or the lateral and depth distributions of elements. The calibration procedure typically used involves placing a micro-droplet (˜?l) of the standard solution onto a silicon wafer (or quartz backing). After evaporation of the solvent, the residual amount of elements is used as a reference standard. Knowledge of the distribution of residue material on the substrate surface is crucial for precise quantification. In the present work the investigation of the lateral distribution of elements in the multielemental calibrating samples, containing the 23 most commonly studied elements, by using the synchrotron radiation based micro X-ray fluorescence is presented. The goal of this project was the study of a uniformity of the elemental distributions and determination of the residual elements morphology depending on the temperature of the drying process. The X-ray images were compared with optical and SEM images. Paper presents in details the experimental setup, sample preparation procedures, measurements and results. In the analysis of the X-ray images of the sample dried in high temperature the censoring approach was applied improving the quality of statistical analysis. The information on the elements distribution in the calibrating samples can be useful for developing more accurate calibration procedures applied in quantitative analysis of surface sensitive TXRF and GEXRF techniques.

Kubala-Kuku?, A.; Bana?, D.; Pajek, M.; Szlachetko, J.; Jagodzi?ski, P.; Susini, J.; Salomé, M.

2013-12-01

163

A 30 nm-resolution hard X-ray microscope with X-ray fluorescence mapping capability at BSRF.  

PubMed

A full-field transmission X-ray microscope (TXM) operating continuously from 5 keV to 12 keV with fluorescence mapping capability has been designed and constructed at the Beijing Synchrotron Radiation Facility, a first-generation synchrotron radiation facility operating at 2.5 GeV. Spatial resolution better than 30 nm has been demonstrated using a Siemens star pattern in both absorption mode and Zernike phase-contrast mode. A scanning-probe mode fluorescence mapping capability integrated with the TXM has been shown to provide 50 p.p.m. sensitivity for trace elements with a spatial resolution (limited by probing beam spot size) of 20 ľm. The optics design, testing of spatial resolution and fluorescence sensitivity are presented here, including performance measurement results. PMID:23093765

Yuan, Qingxi; Zhang, Kai; Hong, Youli; Huang, Wanxia; Gao, Kun; Wang, Zhili; Zhu, Peiping; Gelb, Jeff; Tkachuk, Andrei; Hornberger, Benjamin; Feser, Michael; Yun, Wenbing; Wu, Ziyu

2012-09-01

164

First combined total reflection X-ray fluorescence and grazing incidence X-ray absorption spectroscopy characterization of aeolian dust archived in Antarctica and Alpine deep ice cores  

NASA Astrophysics Data System (ADS)

Aeolian mineral dust archived in polar and mid latitude ice cores represents a precious proxy for assessing environmental and climatic variations at different timescales. In this respect, the identification of dust mineralogy plays a key role. In this work we performed the first preliminary X-ray absorption spectroscopy (XAS) experiments on mineral dust particles extracted from Antarctic and from Alpine firn cores using grazing incidence geometry at the Fe K-edge. A dedicated high vacuum experimental chamber was set up for normal-incidence and total-reflection X-Ray Fluorescence and Absorption Spectroscopy analyses on minor amounts of mineral materials at the Stanford Synchrotron Radiation Laboratory. Results show that this experimental technique and protocol allows recognizing iron inclusion mineral fraction on insoluble dust in the 1-10 ľg range.

Cibin, G.; Marcelli, A.; Maggi, V.; Sala, M.; Marino, F.; Delmonte, B.; Albani, S.; Pignotti, S.

2008-12-01

165

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

Microsoft Academic Search

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,

Shinsuke Kunimura; Jun Kawai

2009-01-01

166

Synchrotron Radiation X-Ray Spectroscopy for Investigations of Intracellular Metallointercalators: X-Ray Fluorescence Imaging and X-Ray Absorption Spectroscopy  

NASA Astrophysics Data System (ADS)

In an effort to determine the therapeutic feasibility of DNA metallointercalators as potential anticancer drugs it is important to confirm that they are capable of targeting DNA in cancer cells or tumours - as is the intended purpose of their design. Microprobe synchrotron radiation X-ray fluorescence (micro-SRXRF) spectroscopy is an ideal technique for investigating the cellular uptake and distribution of metallointercalators. The technique is capable of submicron elemental imaging so that samples as small as individual cells (~10 ?m diameter), and the features within them, can be resolved. Consequently, the technique can ascertain whether intracellular metallointercalators colocalise with DNA; namely, in the nucleus during interphase or at the chromosomes during middle prophase to late anaphase. Metals, such as those commonly incorporated into metallointercalators (e.g., Cr, Ni, Co, Pd, Pt, Ru, Rh), are often naturally present in negligible quantities in cancer cells. This fact, together with their higher atomic number, Z, makes them ideal for direct probing using hard X-ray microprobes (as discussed in Sect. 11.2). There is no need for the incorporation of fluorescent tracker dyes or radioactive labels into their chemical structure. This is advantageous since it is unknown whether such chemical modifications alter the uptake kinetics of the metallointercalator [1, 2].

Dillon, Carolyn T.

167

Industrial Method of X-Ray Fluorescence Analysis of High-Strength Steels.  

National Technical Information Service (NTIS)

A potential method of quantitative analysis of high-strength steels by x-ray fluorescence was investigated. A technique for measuring composition is described in the report. Tool steel, stainless steel, and high temperature alloys of widely varying compos...

D. W. Bowman R. J. Rodgers

1967-01-01

168

Quantification of Element Abundances of Stardust Interstellar Candidates by Synchrotron Radiation X-Ray Fluorescence Spectroscopy  

NASA Astrophysics Data System (ADS)

Orion and Sirius, two Interstellar Dust Candidates from the NASA Stardust mission were analyzed using hyperspectral fluorescence/diffraction nano-X-ray imaging. Correlation spectroscopy of associated elements helped propose an associated mineralogy.

Simionovici, A. S.; Lemelle, L.; Cloetens, P.; Solé, V. A.; Sans Tresseras, J.-A.; Butterworth, A. L.; Westphal, A. J.; Gainsforth, Z.; Stodolna, J.; Allen, C.; Anderson, D.; Ansari, A.; Bajt, S.; Bassim, N.; Bastien, R. S.; Bechtel, H. A.; Borg, J.; Brenker, F. E.; Bridges, J.; Brownlee, D. E.; Burchell, M.; Burghamme, M.; Changela, H.; Davis, A. M.; Doll, R.; Floss, Ch.; Flynn, G. J.; Frank, D. R.; Grün, E.; Heck, Ph. R.; Hillier, J. K.; Hoppe, P.; Hudson, B.; Huth, J.; Hvide, B.; Kearsley, A.; King, A. J.; Lai, B.; Leitner, J.; Leonard, A.; Leroux, H.; Lettieri, R.; Marchant, W.; Nittler, L. R.; Ogliore, R.; Ja Ong, W. J.; Postberg, F.; Price, M. C.; Sandford, S. A.; Schmitz, S.; Schoonjans, T.; Schreiber, K.; Silversmit, G.; Srama, R.; Stephan, Th.; Sterken, V. J.; Stroud, R. M.; Sutton, S.; Trieloff, M.; Tsou, P.; Tsuchiyama, A.; Tyliszczak, T.; Vekemans, B.; Vincze, L.; Von Korff, J.; Wordsworth, N.; Zevin, D.; Zolensky, M. E.

2013-09-01

169

Measurement of Reactor Tube Cladding Thickness by X-Ray Fluorescence Spectrometry.  

National Technical Information Service (NTIS)

An x-ray fluorescence spectrometer was designed and fabricated which nondestructively determines the thickness of aluminum cladding at small suspected thin spots in the inner or outer surface of actinide reactor tubes. The analysis method is based on the ...

R. V. Slates W. E. Stewart

1978-01-01

170

Use of Kirkpatrick-Baez multilayer optics for x-ray fluorescence imaging  

Microsoft Academic Search

We discuss the possibilities for using Kirkpatrick-Baez (K-B) multilayer elements to directly image the fluorescence distribution from a specimen under x-ray illumination. X-ray fluorescence would be collected by K-B elements close to the specimen, with a magnified image formed at an area detector about 0.5 m away from the source. This is in contrast to the use of K-B optics

A. Bakulin; Stephen M. Durbin; Chian Liu; Jenny Erdmann; Albert T. Macrander; Terrence Jach

1998-01-01

171

Angle-resolved soft-x-ray fluorescence and absorption study of graphite  

Microsoft Academic Search

The x-ray fluorescence and absorption of highly oriented pyrolytic graphite have been measured using monochromatic synchrotron radiation. The spectra can be separated into contributions from pi- and sigma-band components by measuring at different angles of incidence and at different emission angles. The shape of the x-ray fluorescence spectra varies dramatically with excitation energy near the C K edge. This dependence

P. Skytt; P. Glans; D. C. Mancini; J.-H. Guo; N. Wassdahl; J. Nordgren; Y. Ma

1994-01-01

172

Development of confocal X-ray fluorescence (XRF) microscopy at the Cornell high energy synchrotron source  

Microsoft Academic Search

A confocal X-ray fluorescence microscope was built at the Cornell High Energy Synchrotron Source (CHESS) to obtain compositional\\u000a depth profiles of historic paintings. The microscope consists of a single-bounce, borosilicate monocapillary optic to focus\\u000a the incident beam onto the painting and a commercial borosilicate polycapillary lens to collect the fluorescent X-rays. The\\u000a resolution of the microscope was measured by scanning

A. R. Woll; J. Mass; C. Bisulca; R. Huang; D. H. Bilderback; S. Gruner; N. Gao

2006-01-01

173

Fast X-Ray Fluorescence Camera Combined with Wide Band Pass Monochromatic Synchrotron Beam  

SciTech Connect

A double W/B4C multilayer monochromator (2d=50.4A) was commissioned for non-scanning X-ray fluorescence (XRF) imaging experiments. The combination of a brilliant multi-pole wiggler source and the present wide band pass monochromator permits 1.2 x 1013 photons/sec at the sample position for 8.04 keV X-rays. Energy resolution {delta}E and {delta}E/E are 300{approx}500 eV and {approx}5%, respectively. The exit beam height is constant for X-ray energy ranging from 5.5 to 13.0 keV. Indirect cooling of the 1st multilayer works successfully. In addition, a new fast CCD camera was developed for quick readout and transfer of the image data. It was found that the typical exposure time for one XRF image with 1000 x 1000 pixels is 0.03{approx}1 sec. This permits in-situ movie recording for the distribution of elements.

Sakurai, Kenji; Mizusawa, Mari [National Institute for Materials Science, 1-2-1, Sengen, Tsukuba, Ibaraki, 305-0047 (Japan)

2004-05-12

174

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

SciTech Connect

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.

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

2010-12-28

175

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

SciTech Connect

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.

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

176

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

NASA Astrophysics Data System (ADS)

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.

Hossain, Mainul; Wang, Chaoming; Su, Ming

2010-12-01

177

Experiment investigation of La(1-x)SrxMnO3 by high-resolution X-ray emission and spin-polarized X-ray absorption spectroscopy.  

PubMed

Big changes in resistivity along with the changing of local structure in some oxide systems, such as high-temperature superconductors and colossal magnetoresistance system, strongly suggest the need of a systematic investigation of their local electronic and atomic structures. In this work we present the high-resolution X-ray emission spectra and the spin-polarized X-ray absorption near-edge spectroscopy (SPXANES) data at the Mn K-edge in the La(1-x)Sr(x)MnO(3). This experiment is based on a high-resolution large-acceptance crystal analyzer based on Si (111) and optimized for X-ray fluorescence spectroscopy. With a spherical bent crystal monochromator, a Mn Kbeta emission spectra with high resolution was obtained with a short collection time and SPXANES spectra of La(1-x)Sr(x)MnO(3) at room temperature were also measured at high temperature. PMID:18319193

Hua, Wei; Zhou, Kejin; Huang, Yuying; Qian, Q; He, Wei; Ma, Sixuan; Chu, Wangsheng; Hu, Tiandou; Wu, Ziyu

2008-01-17

178

CRLS-229 solar X-ray spectrometer/spectroheliograph experiment  

NASA Astrophysics Data System (ADS)

The CRLS-229 Solar X-ray Spectrometer/Spectroheliograph was launched in the solar pointed section of the United States Air Force Space Test Program P78-1 satellite on 24 February 1979. The SOLEX collimated Bragg crystal spectrometer experiment and the MONEX solar X-ray monitor experiment were built by The Aerospace Corporation, and the Naval Research Laboratory supplied the SOLFLEX uncollimated solar flare crystal spectrometer and the MAGMAP magnesium mapping experiment. The SOLEX A spectrometer has a 20 arc sec multigrid collimator, an ADP or RAP crystal, and proportional counter detector with a 25 micrometers thick beryllium window. The SOLEX B spectrometer has a 60 arc sec collimator, an ADP or RAP crystal, and a channel electron multiplier array detector. The SOLEX crystals and detectors can be driven so that either spectrometer exposes RAP to the collimated solar X-rays while the other exposes ADP. The spacecraft pointing system can raster the SOLEX collimator over the whole sum or a 5 x 5 arc minute region to build up a monochromatic image, or it can point the instrument anywhere on the sun so that spectra in the 3-25 angstroms range are obtained.

Landecker, P. B.; Chater, W. T.; Howey, C. K.; McKenzie, D. L.; Rugge, H. R.

1979-10-01

179

A microfocus X-ray fluorescence beamline at Indus-2 synchrotron radiation facility.  

PubMed

A microfocus X-ray fluorescence spectroscopy beamline (BL-16) at the Indian synchrotron radiation facility Indus-2 has been constructed with an experimental emphasis on environmental, archaeological, biomedical and material science applications involving heavy metal speciation and their localization. The beamline offers a combination of different analytical probes, e.g. X-ray fluorescence mapping, X-ray microspectroscopy and total-external-reflection fluorescence characterization. The beamline is installed on a bending-magnet source with a working X-ray energy range of 4-20 keV, enabling it to excite K-edges of all elements from S to Nb and L-edges from Ag to U. The optics of the beamline comprises of a double-crystal monochromator with Si(111) symmetric and asymmetric crystals and a pair of Kirkpatrick-Baez focusing mirrors. This paper describes the performance of the beamline and its capabilities with examples of measured results. PMID:23412498

Tiwari, M K; Gupta, P; Sinha, A K; Kane, S R; Singh, A K; Garg, S R; Garg, C K; Lodha, G S; Deb, S K

2013-02-02

180

X-ray reflectivity and total reflection x-ray fluorescence study of surface oxide evolution in a GaAs/AlAs multilayer system  

NASA Astrophysics Data System (ADS)

Modifications of GaAs/air interface under x-ray exposure have been investigated by means of x-ray reflectometry (XRR). For this purpose a GaAs/AlAs multilayer system was continuously monitored for 90 h while acquiring XRR profiles. Three different starting models for the oxide/contaminants layer were tested for the analysis of XRR data and discussed. The main effect of x-ray exposure, revealed by the three different approaches, is an increase in the thickness of the gallium and arsenic oxides until a saturation value (about 3.0 nm) is reached after about 50 h. Total reflection x-ray fluorescence analysis performed on a couple of twin samples, either irradiated and nonirradiated, confirms that the oxidation process is promoted by x-ray exposure and indicates the presence of a richer As oxide phase at the surface of the x-ray irradiated samples.

Colombi, Paolo; Bontempi, Elza; Depero, Laura E.; Azuma, Yasushi; Fujimoto, Toshiyuki

2009-01-01

181

Portable x-ray fluorescence spectrometer for coating thickness measurement  

SciTech Connect

A handheld x-ray spectrometer has been realized and tested. The purpose of the device is to measure the thickness of coated samples in the range of 1-1500 nm in an industrial environment. Accuracy of {approx}3% has been achieved in this range with a measurement time of 1 min. Automated software has been implemented to allow utilization by a nonspecialist operator. An automated calibration procedure, based on measurements of reference samples, is used.

Carapelle, Alain; Fleury-Frenette, Karl; Collette, Jean-Paul; Garnir, Henri-Pierre; Harlet, Philippe [Centre Spatial de Liege (CSL), University of Liege, Avenue de Pre-Ally, Liege Science Park, 4031 Angleur (Belgium); Institut de Physique Nucleaire, Atomique et de Spectroscopie (IPNAS), University of Liege, 15 Allee du Six Aout, Sart Tilman, 4031 Angleur (Belgium); Arcelor-Mittal Research Liege, Boulevard de Colonster, B57, 4000 Liege (Belgium)

2007-12-15

182

Fluorescent x-ray computed tomography with synchrotron radiation using fan collimator  

NASA Astrophysics Data System (ADS)

We describe a new system of fluorescent x-ray computed tomography applied to image nonradioactive contrast materials in vivo. The system operates on the basis of computed tomography (CT) of the first generation. The experiment was also simulated using the Monte Carlo method. The research was carried out at the BLNE-5A bending-magnet beam line of the Tristan Accumulation Ring in Kek, Japan. An acrylic cylindrical phantom containing five paraxial channels of 5 and 4 mm diameters was imaged. The channels were filled with a diluted iodine-based contrast material, with iodine concentrations of 2 mg/ml and 500 (mu) g/ml. Spectra obtained with the system's high purity germanium (HPGe) detector separated clearly the K(alpha ) and K(beta 1) x-ray fluorescent lines, and the Compton scattering. CT images were reconstructed from projections generated by integrating the counts in these spectral lines. The method had adequate sensitivity and detection power, as shown by the experiment and predicted by the simulations, to show the iodine content of the phantom channels, which corresponded to 1 and 4 (mu) g iodine content per pixel in the reconstructed images.

Takeda, Tohoru; Akiba, Masahiro; Yuasa, Tetsuya; Kazama, Masahiro; Hoshino, Atunori; Watanabe, Yuuki; Hyodo, Kazuyuki; Dilmanian, F. Avraham; Akatsuka, Takao; Itai, Yuji

1996-04-01

183

X-ray absorption fine structure combined with X-ray fluorescence spectrometry  

Microsoft Academic Search

Sn K?1-detecting Sn K-edge XANES spectrum was successfully measured for Pt–Sn\\/SiO2 catalyst (2.5 wt.% Pt, Sn\\/Pt atomic ratio 1.0) in the energy resolution 5.0 eV using Rowland-type fluorescence spectrometer equipped with Ge(13,13,13) bent crystal. The steeper, more clearly resolved XANES spectrum thus obtained could be compared quantitatively to theoretical XANES spectra generated by ab initio calculations for thirteen plausible Pt–Sn site models

Yasuo Izumi; Dilshad Masih; Eric Roisin; Jean-Pierre Candy; Hajime Tanida; Tomoya Uruga

2007-01-01

184

A tube-excited x-ray fluorescence spectrometer for use in small-diameter boreholes  

SciTech Connect

A portable in-situ x-ray fluorescence analytical system that uses an x-ray tube excitation source and a cooled Si(Li) spectrometer for detecting characteristic emission x rays has been developed for use in small-diameter wells and boreholes. The 15-watt, iron-anode x-ray tube operates up to 30 kV. Three wells at the Sandia National Laboratory Chemical Waste Landfill, lined with 76 {mu} thick polyethylene, were logged specifically for Cr contamination. Detection limits below 50 ppM were achieved with counting intervals of 600 seconds and with the Si(Li) detector operating at 450-eV resolution (full width at half maximum [FWHM] for the Mn K-alpha x ray).

Reeves, J.H.; Arthur, R.J.; Brodzinski, R.L.; Shepard, C.L.

1995-04-01

185

Detectors for Ultrafast X-ray Experiments at SPPS  

SciTech Connect

The paper describes two detectors designed specifically for the SPPS ultrafast x-ray source, one of which provides 2-D position and intensity information, and the other acts as a low-noise point detector for diffraction experiments. The beam position monitor (BPM) was used as a reference detector for most of the experiments performed there, and the point detector was used for pump-probe experiments involving phonons in bismuth and on photosensitive metal-organic crystals. The schedule for development of these detectors was extremely tight, so as much as possible we used available designs for amplifiers etc.

Siddons, D. Peter; Kuczewski, Anthony J.; Yu, Bo; Warren, John [National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973 (United States); Rudati, Juana; Fuoss, Paul [Argonne National Laboratory, Argonne, Illinois 60439 (United States); Hastings, Jerome B.; Kaspar, Jen D.; Meyer, Drew A. [Stanford Linear Accelerator Center, Menlo Park, California 94025 (United States)

2007-01-19

186

Imaging experiments of Ne-like x-ray lasers  

SciTech Connect

We discuss high resolution two-dimensional near-field images of the neon-like nickel and germanium x-ray laser obtained using the Asterix laser at the Max-Planck-Institute and the Nova laser at Lawrence Livermore National Laboratory. Our imaging diagnostic consisted of a concave multilayer mirror that imaged the output end of the x-ray laser line onto a backside illuminated x-ray CCD detector. A 25 microm thick wire positioned at the end of the target provided a spatial fiducial. With the Asterix iodine laser, a prepulse 5.23 ns before the main pulse, was used to irradiate slab targets. A great deal of structure was observed in the near field images, particularly in the J=0-1 emission. We observed a large difference in the spatial dependence of the J=0-1 and J=2-1 lines of germanium, with the J=2-1 emission peaking farther away from the original target surface. A larger prepulse moved the peak emission farther away from the target surface. For the Nova experiments we used a series of 100 ps pulses spaced 400 ps apart to illuminate a germanium target. We obtained high resolution images of both the J=0-1 and J=2-1 lines of Ge. These measurements are compared to hydrodynamic simulations coupled with atomic kinetics and including refraction effects.

Moreno, J.C., Nilsen, J.; Barbee, T.W.; Da Silva, L.B.; Fill, E.; Li, Y,; Lu, P.

1997-06-01

187

Phase Recovery in Coherent X-Ray Diffraction (CXD) Experiments  

NASA Astrophysics Data System (ADS)

Coherent X-Ray Diffraction (CXD) consists of measurements of the beam scattered from structures which lie entirely within the coherence volume of the x-ray beam. As a result, CXD probes the specific properties of a coherently illuminated volume; conventional x-ray diffraction experiments, in contrast, can only yield information about the ensemble average over many coherence volumes. Recent developments in insertion devices, beamline optics, small beam techniques, and high-resolution area detectors comprise enabling technologies for CXD. One-dimensional CXD has been applied to post-etch Si(111) surface evolution in a specular reflection geometry. Two-dimensional CXD data has been obtained from the (100) reflection of a Cu_3Au(111) thin film. The Gerchberg-Saxton algorithm has been applied to reconstruct the phase of the measured CXD amplitude, allowing reconstructions of the surface morphology to be made. Independent reconstructions initialized with randomized phases converged to similar surfaces about ten percent of the time.

Pitney, J. A.; Robinson, I. K.; Libbert, J. L.; Vartaniants, I. A.

1998-03-01

188

Beamline Reconfiguring and Commissioning for X-Ray Microdiffraction Experiments  

NASA Astrophysics Data System (ADS)

The 5C1 beamline at Pohang Light Source (PLS) was reconfigured into a beamline for X-ray microdiffraction (XMD) experiments through works during the year 2008 and has been commissioned recently. A slit, two ionization chambers, a shutter, a monochromator, a Kirkpatrick-Baez (K-B) mirror system, a sample stage assembly, and an X-ray CCD detector were newly installed and a series of LabVIEW applications to control these experimental equipments and to execute the data acquisition was completed. After the alignment of the equipments, a 100 ?m×100 ?m beam defined by the slit was focused down to less than 3 ?m in the horizontal and vertical planes by a pair of vertically and horizontally focusing mirrors. Then, the X-ray CCD detector took test diffraction images of a Ge single crystal on the sample holder of the sample stage assembly. The paper describes the details of the equipments and several new improvements of the new 5C1 beamline, reports the processes and results of the commissioning work, and shows the experimental performance expected from the diffraction images.

Gil, K. H.; Lim, J.; Choi, H. J.; Ahn, S. J.; Bark, C. W.; Lim, J. H.; Huang, J. Y.

2010-06-01

189

CRLS-229 solar X-ray spectrometer/spectroheliograph experiment  

NASA Astrophysics Data System (ADS)

The CRLS-229 solar X-ray spectrometer/spectroheliograph payload was launched in the solar pointed section of the U.S. Air Force Space Test Program P78-1 satellite on 24 February 1979. The payload consists of two instruments furnished by the Aerospace Corporation, known as SOLEX and MONEX, and two instruments furnished by the Naval Research Laboratory. The SOLEX instrument provides maps of the sun in individual X-ray spectral lines and also obtains spectra in the 3 to 25 A wavelength interval while pointed at a specific solar region. The basic SOLEX hardware consists of two multigrid collimators with 20 arc sec and 60 arc sec spatial resolution, RAP and ADP scanning high resolution Bragg crystals, and a proportional counter and an array of channel electron multipliers as detectors. The MONEX experiment, consisting of two proportional counters, provides full disk solar X-ray intensity with moderate spectral resolution and excellent temporal resolution in the 1 to 140 keV energy interval. Examples of data from the spectrometer/spectroheliograph are presented.

Landecker, P. B.; McKenzie, D. L.; Rugge, H. R.

1979-01-01

190

Techniques for depth heterogeneity identification in X-ray fluorescence  

NASA Astrophysics Data System (ADS)

Two methods enabling depth heterogeneity to be recognized and taken into account in quantitative analysis have been elaborated and then applied to various samples. The first method involves predicting the K?/K? (or L lines) ratios for all identified elements. The second method is based on comparing the spectra measured on different geometric arrangements. In particular, sample tilting makes identification of depth heterogeneities possible. If the sample is heterogeneous, the heights of some peaks in the X-ray spectra change according to the depth distribution of the corresponding elements. Monte Carlo simulations with the MCNP4C2 code can be used to predict these changes and interpret the experimental results.

Trojek, T.; ?echák, T.; Musílek, L.

2007-10-01

191

X-ray fluorescence-spectometer/diffractometer for future lunar lander/rover mission  

NASA Astrophysics Data System (ADS)

A miniaturized scientific instrument is being developed for a Japanese future lunar lander and rover mission to perform both of X-ray fluorescence (XRF) spectroscopy and X ray diffractometry (XRD). Onboard micro X ray tube with a fine focused-- collimator generates primary X-rays that excites fluorescence X rays characteristic- to component elements of the targeted sample and, at the same time, are scattered into X-ray diffraction pattern reflecting d-spacings of the component minerals. By using two -dimensional X-ray detector such as charge-coupled devices (CCD), pulse height analysis for XRF and pattern extraction for XRD will be simultaneously carried out. The instrument covers energy detection range from 1 to 10 KeV for analysis of major rock-forming elements, and measures diffraction angle from 20 to 90 degree for identification and quantification of major minerals. A lunar lander/rover mission is studied underway a s a geological observation. Candidate landing sites are proximity of central peaks of impact craters or volcanic structures (dome or cone). After collected by sampling devices, the surfa ce rocks, breccias and soils from those landing sites are transported into the geological analysis package. Microscopy with visible to near-infrared wavelengths and XRF/XRD analysis will provide texture and elemental composition of each sample and inform its mineralogy. These scientific information will improve understanding of the internal structure and evolutional process of the Moon.

Shirai, K.; Aoki, M.; Ito, S.; Okada, T.; Yamamoto, Y.; Arai, T.; Akagawa, K.; Kato, M.

192

Multielement Detectors for High Energy SR X-ray Experiments  

SciTech Connect

There have been two different multielement detectors developed at the SPring-8 facility for high energy SR X-ray experiments beyond 100 keV, i.e., the 128-channel microstrip Germanium detector and the YAP imager. The farmer one is optimized for spectroscopy required in Compton scattering experiments, the latter for imaging in time-resolved diffraction pattern observation. With latest experimental results obtained with these two detectors, the design concepts are discussed together with some technical issues needed for further research.

Suzuki, Masayo; Toyokawa, Hidenori; Hirota, Katsuya [Japan Synchrotron Radiation Research Institute (JASRI), SPring-8, Kouto, Mikazuki, Hyogo 679-5198 (Japan)

2004-05-12

193

Development of a total reflection X-ray fluorescence spectrometer for ultra-trace element analysis  

Microsoft Academic Search

A simple and fairly inexpensive total reflection X-ray fluorescence (TXRF) spectrometer has been designed, constructed and\\u000a realized. The spectrometer is capable of ultra-trace multielement analysis as well as performs surface characterization of\\u000a thin films. The TXRF setup comprises of an X-ray generator, a slit-collimator arrangement, a monochromator\\/cutoff-stage, a\\u000a sample reflector stage and an X-ray detection system. The glancing angle of

M. K. Tiwari; B. Gowrishankar; V. K. Raghuvanshi; R. V. Nandedkar; K. J. S. Sawhney

2002-01-01

194

Micro x-ray fluorescence as a high throughput screening method for metal chelating compounds  

Microsoft Academic Search

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

Edel M. Minogue; George J. Havrilla; Tammy P. Taylor; Anthony K. Burrell; Benjamin P. Warner

2005-01-01

195

Element distribution in the brain sections of rats measured by synchrotron radiation X-ray fluorescence  

Microsoft Academic Search

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,

N. Q. Liu; F. Zhang; X. F. Wang; Z. Y. Zhang; Z. F. Chai; Y. Y. Huang; W. He; X. Q. Zhao; A. J. Zuo; R. Yang

2004-01-01

196

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

Microsoft Academic Search

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 (3.16×106 counts s-1), and can be theoretically extended to roughly 5×107 counts s-1 if used on a multibunch

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

1990-01-01

197

Gadolinium concentration analysis in brain phantom by X-ray fluorescence.  

PubMed

We have measured the X-ray fluorescence from gadolinium as a function of concentration and position in tumors of different sizes and shapes in a head phantom. The gadolinium fluorescence was excited with a 36 GBq Am-241 source. The fluorescence signal was detected with a CdTe detector and a multi-channel analyzer. The fluorescence peak was clearly separated from the scattered X-rays. Concentrations of 5.62-78.63 mg/ml of Gd ion were used in 1, 2, and 3 cm diameter spherical tumors and a 2x4 cm oblate spheroid tumor. The data show trends approaching saturation for the highest concentrations, probably due to reabsorption in the tumor. A comparison of X-ray photographic imaging and densitometer measurements to determine concentration is also presented. PMID:20596811

Almalki, Musaed; Majid, Samir Abdul; Butler, Philip H; Reinisch, Lou

2010-07-02

198

Disparity in formulations used for fluorescent X-ray intensity measurements.  

PubMed

The paper presents a problem in computations of X-ray fluorescence cross-sections, shell/sub-shell fluorescence yields, Coster-Kronig yields, vacancy alignment, etc. from X-ray fluorescence (XRF) studies. While using barn/atom as a unit for cross-sections if the atomic masses are not considered it causes a discrepancy in the measured cross-section, yield and alignment values. Most of the earlier publications are being quoted where such an oversight has occurred and discrepancy is evident. PMID:21676620

Mittal, Raj; Gupta, Sheenu

2011-06-02

199

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

NASA Astrophysics Data System (ADS)

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.

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

2012-06-01

200

Modeling current and proposed COMET x-ray laser experiments  

NASA Astrophysics Data System (ADS)

We model recent experiments done using the COMET laser at Lawrence Livermore National Laboratory to illuminate slab targets of Pd up to 1.25 cm long with a two joule, 600 ps prepulse followed 700 psec later by a six joule, six psec drive pulse. The experiments measure the two-dimensional near-field and far-field laser patterns for the 14.7 nm Ni-like Pd x-ray laser line. The experiments are modeled using the LASNEX code to calculate the hydrodynamic evolution of the plasma and provide the temperatures and densities to the CRETIN code, which then does the kinetics calculations to determine the gain. Using a ray tracing code to simulate the near and far-field output the simulations are then compared with experiments. In addition we model recent experiments that used a streak camera to measure the time duration of the Pd X-ray laser when pumped with a constant energy short pulse with different time durations that ranged from 0.5 to 27 ps.

Nilsen, Joseph; Dunn, James; Smith, Raymond F.

2003-12-01

201

Hybrid System for Simultaneous Fluorescence and X-Ray Computed Tomography  

Microsoft Academic Search

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

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

2010-01-01

202

Analysis of wrapped or cased object by a hand-held X-ray fluorescence spectrometer  

Microsoft Academic Search

Metals, alloys, and poisoned food were analyzed with a hand-held X-ray fluorescence (XRF) spectrometer, with a shield (wrapping or casing material) inserted between these objects and the spectrometer, in order to examine the possibility of analyzing the contents of packages. Elements such as Fe, Cr, Ni, Cu, Zn, Pb, Mo, and As were detected in the objects. The fluorescent intensity

Hiroyuki Ida; Jun Kawai

2005-01-01

203

Wavelength-Dispersive Total Reflection X-Ray Fluorescence with High-Brilliance Undulator Radiation at SPring8  

Microsoft Academic Search

Wavelength-dispersive total reflection X-ray fluorescence (WD-TXRF) equipment supported by an energy-dispersive (ED) solid-state detector (SSD) has been developed and installed in the BL16XU Industrial Consortium ID Beamline for Material Research at the SPring-8 synchrotron radiation research facility. Equipment specifications are given and results from our initial experiment are discussed in this paper. In the experiment on the sensitivity of detection

Naoki Awaji; Shinji Ozaki; Junichi Nishino; Sinichi Noguchi; Tohru Yamamoto; Takashi Syoji; Motoyuki Yamagami; Akira Kobayashi; You Hirai; Masahiro Shibata; Koji Yamaguchi; Kuang-Yu Liu; Seiji Kawado; Mamoru Takahashi; Shigeru Yasuami; Ichiro Konomi; Shigeru Kimura; Yasuharu Hirai; Masaki Hasegawa; Satoshi Komiya; Takayuki Hirose; Toshihiro Okajima

2000-01-01

204

Development of a micro-X-ray fluorescence system based on polycapillary X-ray optics for non-destructive analysis of archaeological objects  

NASA Astrophysics Data System (ADS)

A new micro-X-ray fluorescence (micro-XRF) system based on rotating anode X-ray generator and polycapillary X-ray optics has been set up in XOL Lab, BNU, China, in order to be used for analysis of archaeological objects. The polycapillary X-ray optics used here can focus the primary X-ray beam down to tens of micrometers in diameter that allows for non-destructive and local analysis of sub-mm samples with minor/trace level sensitivity. The analytical characteristics and potential of this micro-XRF system in archaeological research are discussed. Some described uses of this instrument include studying Chinese ancient porcelain.

Cheng, Lin; Ding, Xunliang; Liu, Zhiguo; Pan, Qiuli; Chu, Xuelian

2007-08-01

205

Determination of X-ray compression efficiency of a thin film X-ray waveguide structure using marker layer fluorescence  

NASA Astrophysics Data System (ADS)

We demonstrate that a thin marker layer, sandwiched in the guiding medium of a thin film planner X-ray waveguide structure, can be used to determine X-ray compression efficiency for a particular excitation mode. It can also be used in evaluating the transmission efficiency of waveguide structure and for the determination of X-ray intensities reaching the waveguide exit. This approach has been applied for determining X-ray compression and transmission efficiency of a Mo/B4C/Mo based X-ray waveguide structure, by inserting a thin Fe marker layer.

Tiwari, M. K.; Nayak, M.; Lodha, G. S.; Nandedkar, R. V.

2007-02-01

206

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

NASA Astrophysics Data System (ADS)

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

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

2009-07-01

207

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

USGS Publications Warehouse

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

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

1990-01-01

208

Using a charge-coupled device (CCD) to simultaneously gather x-ray fluorescence (XRF) and x-ray diffraction (XRD) information  

NASA Astrophysics Data System (ADS)

A breadboard setup constructed at MOXTEK, Inc., is capable of capturing both x-ray diffraction (XRD) and x-ray fluorescence (XRF) information simultaneously using a charge-coupled device (CCD) as the x-ray detector. This preliminary setup will lead to a prototype simultaneous XRD/XRF instrument. NASA is funding the project because it could be used for future Mars missions for analysis of rocks. The instrument uses a CCD to capture both the energy and the position of an incoming x-ray. This is possible because each pixel acts as a spatially addressable energy- dispersive detector. A powdered sample of material is placed in front of the CCD, which in turn is bombarded by a collimated x-ray beam. The instrument's critical features, the x-ray source, collimation optics and x-ray transparent windows need to be optimized in the size and power to allow the instrument to be portable. In this paper the instrument's design parameters as well as the properties of both the CCD as x-ray detector and the low-power consumption tube are investigated.

Cornaby, S.; Grow, T. D.; Reyes-Mena, Arturo; Moody, Paul W.; Stradling, A.; Hughes, T.; Knight, Larry V.

2002-01-01

209

High-definition X-ray fluorescence elemental mapping of paintings.  

PubMed

A historical self-portrait painted by Sir Arthur Streeton (1867-1943) has been studied with fast-scanning X-ray fluorescence microscopy using synchrotron radiation. One of the technique's unique strengths is the ability to reveal metal distributions in the pigments of underlying brushstrokes, thus providing information critical to the interpretation of a painting. We have applied the nondestructive technique with the event-mode Maia X-ray detector, which has the capability to record elemental maps at megapixels per hour with the full X-ray fluorescence spectrum collected per pixel. The painting poses a difficult challenge to conventional X-ray analysis, because it was completely obscured with heavy brushstrokes of highly X-ray absorptive lead white paint (2PbCO(3)ˇPb(OH)(2)) by the artist, making it an excellent candidate for the application of the synchrotron-based technique. The 25 megapixel elemental maps were successfully observed through the lead white paint across the 200 × 300 mm(2) scan area. The sweeping brushstrokes of the lead white overpaint contributed significant detrimental structure to the elemental maps. A corrective procedure was devised to enhance the visualization of the elemental maps by using the elastic X-ray scatter as a proxy for the lead white overpaint. We foresee the technique applied to the most demanding of culturally significant artworks where conventional analytical methods are inadequate. PMID:22414158

Howard, Daryl L; de Jonge, Martin D; Lau, Deborah; Hay, David; Varcoe-Cocks, Michael; Ryan, Chris G; Kirkham, Robin; Moorhead, Gareth; Paterson, David; Thurrowgood, David

2012-03-21

210

Spectrally resolving and scattering-compensated x-ray luminescence/fluorescence computed tomography  

PubMed Central

The nanophosphors, or other similar materials, emit near-infrared (NIR) light upon x-ray excitation. They were designed as optical probes for in vivo visualization and analysis of molecular and cellular targets, pathways, and responses. Based on the previous work on x-ray fluorescence computed tomography (XFCT) and x-ray luminescence computed tomography (XLCT), here we propose a spectrally-resolving and scattering-compensated x-ray luminescence/fluorescence computed tomography (SXLCT or SXFCT) approach to quantify a spatial distribution of nanophosphors (other similar materials or chemical elements) within a biological object. In this paper, the x-ray scattering is taken into account in the reconstruction algorithm. The NIR scattering is described in the diffusion approximation model. Then, x-ray excitations are applied with different spectra, and NIR signals are measured in a spectrally resolving fashion. Finally, a linear relationship is established between the nanophosphor distribution and measured NIR data using the finite element method and inverted using the compressive sensing technique. The numerical simulation results demonstrate the feasibility and merits of the proposed approach.

Cong, Wenxiang; Shen, Haiou; Wang, Ge

2011-01-01

211

A high-resolution large-acceptance analyzer for X-ray fluorescence and Raman spectroscopy  

SciTech Connect

A newly designed multi-crystal X-ray spectrometer and its applications in the fields of X-ray fluorescence and X-ray Raman spectroscopy are described. The instrument is based on 8 spherically curved Si crystals, each with a 3.5 inch diameter form bent to a radius of 86 cm. The crystals are individually aligned in the Rowland geometry capturing a total solid angle of 0.07 sr. The array is arranged in a way that energy scans can be performed by moving the whole instrument, rather than scanning each crystal by itself. At angles close to back scattering the energy resolution is between 0.3 and 1 eV depending on the beam dimensions at the sample. The instrument is mainly designed for X-ray absorption and fluorescence spectroscopy of transition metals in dilute systems such as metalloproteins. First results of the Mn K{beta} (3p -> 1s) emission in photosystem II are shown. An independent application of the instrument is the technique of X-ray Raman spectroscopy which can address problems similar to those in traditional soft X-ray absorption spectroscopies, and initial results are presented.

Bergmann, Uwe; Cramer, Stephen P.

2001-08-02

212

Medical imaging by fluorescent x-ray CT: its preliminary clinical evaluation  

NASA Astrophysics Data System (ADS)

Fluorescent x-ray CT (FXCT) with synchrotron radiation (SR) is being developed to detect the very low concentration of specific elements. The endogenous iodine of the human thyroid and the non-radioactive iodine labeled BMIPP in myocardium were imaged by FXCT. FXCT system consists of a silicon (111) double crystal monochromator, an x-ray slit, a scanning table for object positioning, a fluorescent x-ray detector, and a transmission x-ray detector. Monochromatic x-ray with 37 keV energy was collimated into a pencil beam (from 1 mm to 0.025 mm). FXCT clearly imaged endogenous iodine of thyroid and iodine labeled BMIPP in myocardium, whereas transmission x-ray CT could not demonstrate iodine. The distribution of iodine was heterogeneous within thyroid cancer, and its concentration was lower than that of normal thyroid. Distribution of BMIPP in normal rat myocardium was almost homogeneous; however, reduced uptake was slightly shown in ischemic region. FXCT is a highly sensitive imaging modality to detect very low concentration of specific element and will be applied to reveal endogenous iodine distribution in thyroid and to use tracer study with various kinds of labeled material.

Takeda, Tohoru; Zeniya, Tsutomu; Wu, Jin; Yu, Quanwen; Lwin, Thet T.; Tsuchiya, Yoshinori; Rao, Donepudi V.; Yuasa, Tetsuya; Yashiro, Toru; Dilmanian, F. Avraham; Itai, Yuji; Akatsuka, Takao

2002-01-01

213

Spectrally resolving and scattering-compensated x-ray luminescence/fluorescence computed tomography  

NASA Astrophysics Data System (ADS)

The nanophosphors, or other similar materials, emit near-infrared (NIR) light upon x-ray excitation. They were designed as optical probes for in vivo visualization and analysis of molecular and cellular targets, pathways, and responses. Based on the previous work on x-ray fluorescence computed tomography (XFCT) and x-ray luminescence computed tomography (XLCT), here we propose a spectrally-resolving and scattering-compensated x-ray luminescence/fluorescence computed tomography (SXLCT or SXFCT) approach to quantify a spatial distribution of nanophosphors (other similar materials or chemical elements) within a biological object. In this paper, the x-ray scattering is taken into account in the reconstruction algorithm. The NIR scattering is described in the diffusion approximation model. Then, x-ray excitations are applied with different spectra, and NIR signals are measured in a spectrally resolving fashion. Finally, a linear relationship is established between the nanophosphor distribution and measured NIR data using the finite element method and inverted using the compressive sensing technique. The numerical simulation results demonstrate the feasibility and merits of the proposed approach.

Cong, Wenxiang; Shen, Haiou; Wang, Ge

2011-06-01

214

X-Ray Fluorescence (XRF) spectrometry for materials analysis and discovering "the atomic number"  

NSDL National Science Digital Library

In this experiment students use XRF spectroscopy to analyze a sampleâs elemental composition. From the characteristic X-ray energies, Moseleyâs Law, a proof of the existence of the atomic number, is verified. The atomic number increases in regular steps with an increase in the characteristic X-ray energy. We will use this relationship to find the Rydbergâs energy constant and screening coefficient for K X-rays. This lab is designed for the student to learn to: 1. differentiate between characteristic X-rays and Bremsstrahlung radiations, 2. use characteristic X-rays to identify elements, 3. acquire a spectrum, calibrate it and use it for qualitative (element identification) as well as quantitative (elemental concentration) analysis, and finally, 4. verify Moseleyâs law and the validity of an atomic number.

Khalid, Asma; Khan, Aleena T.; Anwar, Muhammad S.

2012-06-06

215

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

216

X-ray fluorescence spectroscopy from ions at charged vapor/water interfaces  

SciTech Connect

X-ray fluorescence spectra from monovalent ions (Cs{sup +}) that accumulate from dilute solutions to form an ion-rich layer near a charged Langmuir monolayer are presented. For the salt solution without the monolayer, the fluorescence signals below the critical angle are significantly lower than the detection sensitivity and only above the critical angle signals from the bulk are observed. In the presence of a monolayer that provides surface charges, strong fluorescence signals below the critical angle are observed. Ion density accumulated at the interface are determined from the fluorescence. The fluorescent spectra collected as a function of incident x-ray energy near the L{sub III} edge yield the extended absorption spectra from the ions, and are compared to recent independent results. The fluorescence data from divalent Ba{sup 2+} with and without monolayer are also presented.

Bu Wei; Vaknin, David [Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States)

2009-04-15

217

Microprobe x-ray fluorescence with the use of point-focusing diffractors  

SciTech Connect

A toroidal point-focusing mica crystal diffractor was used to focus monochromatic x rays from a microfocus x-ray source operated at 0.1 mA and 30 kV. The CuK{sub {alpha}} x-ray focal spot of 50{mu}m{times}85{mu}m had 1.6{times}10{sup 4}photons/s/{mu}m{sup 2}. Microprobe x-ray fluorescence (MXRF) spectra were recorded with a Si(Li) energy dispersive detector for bulk specimens of GaAs, Si, and Muscovite. Low background due to monochromatic excitation resulted in predicted detection limits as low as 2 ppm for a measurement time of 500 s. Laboratory MXRF systems based on point-focusing diffractors were shown to provide lower detection limits, larger working distance, and higher theoretical intensity than systems using capillary optics. {copyright} {ital 1997 American Institute of Physics.}

Chen, Z.W.; Wittry, D.B. [Department of Materials Science and Engineering, University of Southern California, Los Angeles, California 90089-0241 (United States)

1997-09-01

218

X-ray fluorescence spectrometry for high throughput analysis of atmospheric aerosol samples: The benefits of synchrotron X-rays  

NASA Astrophysics Data System (ADS)

The determination of trace element mass concentrations in ambient air with a time resolution higher than one day represents an urgent need in atmospheric research. It involves the application of a specific technique both for the aerosol sampling and the subsequent analysis of the collected particles. Beside the intrinsic sensitivity of the analytical method, the sampling interval and thus the quantity of collected material that is available for subsequent analysis is a major factor driving the overall trace element detection power. This is demonstrated for synchrotron radiation X-ray fluorescence spectrometry (SR-XRF) of aerosol samples collected with a rotating drum impactor (RDI) in hourly intervals and three particle size ranges. The total aerosol mass on the 1-h samples is in the range of 10 ľg. An experimental detection of the nanogram amounts of trace elements with the help of synchrotron X-rays was only achievable by the design of a fit-for-purpose sample holder system, which considered the boundary conditions both from particle sampling and analysis. A 6-ľm polypropylene substrate film has evolved as substrate of choice, due to its practical applicability during sampling and its suitable spectroscopic behavior. In contrast to monochromatic excitation conditions, the application of a 'white' beam led to a better spectral signal-to-background ratio. Despite the low sample mass, a counting time of less than 30 s per 1-h aerosol sample led to sufficient counting statistics. Therefore the RDI-SR-XRF method represents a high-throughput analysis procedure without the need for any sample preparation. The analysis of a multielemental mass standard film by SR-XRF, laboratory-based wavelength-dispersive XRF spectrometry and laboratory-based micro XRF spectrometry showed that the laboratory-based methods were no alternatives to the SR-XRF method with respect to sensitivity and efficiency of analysis.

Bukowiecki, Nicolas; Lienemann, Peter; Zwicky, Christoph N.; Furger, Markus; Richard, Agnes; Falkenberg, Gerald; Rickers, Karen; Grolimund, Daniel; Borca, Camelia; Hill, Matthias; Gehrig, Robert; Baltensperger, Urs

2008-09-01

219

Modeling of x-ray fluorescence using MCNPX and Geant4  

SciTech Connect

X-Ray Fluorescence (XRF) is one of thirteen non-destructive assay techniques being researched for the purpose of quantifying the Pu mass in used fuel assemblies. The modeling portion of this research will be conducted with the MCNPX transport code. The research presented here was undertaken to test the capability of MCNPX so that it can be used to benchmark measurements made at the ORNL and to give confidence in the application of MCNPX as a predictive tool of the expected capability of XRF in the context of used fuel assemblies. The main focus of this paper is a code-to-code comparison between MCNPX and Geant4 code. Since XRF in used fuel is driven by photon emission and beta decay of fission fragments, both terms were independently researched. Simple cases and used fuel cases were modeled for both source terms. In order to prepare for benchmarking to experiments, it was necessary to determine the relative significance of the various fission fragments for producing X-rays.

Rajasingam, Akshayan [Los Alamos National Laboratory; Hoover, Andrew S [Los Alamos National Laboratory; Fensin, Michael L [Los Alamos National Laboratory; Tobin, Stephen J [Los Alamos National Laboratory

2009-01-01

220

A synchrotron radiation microprobe for X-ray fluorescence and microtomography at ELETTRA  

NASA Astrophysics Data System (ADS)

A synchrotron radiation microscope based on X-ray fluorescence and computed microtomography for advanced applications in biomedicine, environmental sciences, geology and materials science is described. This microscope will utilize the radiation produced by a bending magnet of ELETTRA, the third-generation, high-brilliance synchrotron radiation facility being built in Trieste. Various wide-band-pass mirror systems operating in an energy range between 7 and 17 keV have been designed. For example, multilayer-coated mirrors in the Kirkpatrick-Baez configuration can produce a spatial resolution of 1 ?m2 for a flux in excess of 108 photons per second on the sample (E = 12 keV, E/?E = 10). This X-ray microprobe will allow micrometric mapping of trace and minor elements and computed tomographic imaging with high resolution, opening a new realm of experiments in different fields of science, such as in vivo elemental scanning and microtomography of cultured cells, analysis of single atmospheric particulates, analysis of cosmic debris collected from the stratosphere and antarctic ice, etc. The preliminary design of the beam line and the performance of the microprobe are discussed.

Tuniz, Claudio; Devoti, Roberto; Santoro, Giuseppe; Zanini, Franco

1990-04-01

221

Simultaneous X-ray fluorescence and ptychographic microscopy of Cyclotella meneghiniana.  

PubMed

Scanning X-ray fluorescence microscopy (XFM) is a particularly useful method for studying the spatial distribution of trace metals in biological samples. Here we demonstrate the utility of combining coherent diffractive imaging (CDI) with XFM for imaging biological samples to simultaneously produce high-resolution and high-contrast transmission images and quantitative elemental maps. The reconstructed transmission function yields morphological details which contextualise the elemental maps. We report enhancement of the spatial resolution in both the transmission and fluorescence images beyond that of the X-ray optics. The freshwater diatom Cyclotella meneghiniana was imaged to demonstrate the benefits of combining these techniques that have complementary contrast mechanisms. PMID:23038378

Vine, D J; Pelliccia, D; Holzner, C; Baines, S B; Berry, A; McNulty, I; Vogt, S; Peele, A G; Nugent, K A

2012-07-30

222

X-RAY FLUORESCENCE ANALYSIS OF HANFORD LOW ACTIVITY WASTE SIMULANTS METHOD DEVELOPMENT  

SciTech Connect

The x-ray fluorescence laboratory (XRF) in the Analytical Development Directorate (ADD) of the Savannah River National Laboratory (SRNL) was requested to develop an x-ray fluorescence spectrometry method for elemental characterization of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) pretreated low activity waste (LAW) stream to the LAW Vitrification Plant. The WTP is evaluating the potential for using XRF as a rapid turnaround technique to support LAW product compliance and glass former batching. The overall objective of this task was to develop an XRF analytical method that provides rapid turnaround time (<8 hours), while providing sufficient accuracy and precision to determine variations in waste.

Jurgensen, A; David Missimer, D; Ronny Rutherford, R

2007-08-08

223

The MicroAnalysis Toolkit: X-ray Fluorescence Image Processing Software  

SciTech Connect

The MicroAnalysis Toolkit is an analysis suite designed for the processing of x-ray fluorescence microprobe data. The program contains a wide variety of analysis tools, including image maps, correlation plots, simple image math, image filtering, multiple energy image fitting, semi-quantitative elemental analysis, x-ray fluorescence spectrum analysis, principle component analysis, and tomographic reconstructions. To be as widely useful as possible, data formats from many synchrotron sources can be read by the program with more formats available by request. An overview of the most common features will be presented.

Webb, S. M. [Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States)

2011-09-09

224

Monte Carlo methods for the in vivo analysis of Cisplatin using x-ray fluorescence  

Microsoft Academic Search

A Monte Carlo method has been used to model the measument of cisplatin uptake with in vivo X-ray fluorescence. A user-code has been written for the EGS4 Monte Carlo system that incorporates linear polarisation and multiple element fluorescence extensoions. The yield of fluorescent photons to the mainly Compton scattered background is computed for our detector arrangement. The detector consists of

R. P. Hugtenburg; J. R. Turner; D. M. Mannering; B. A. Robinson

1998-01-01

225

A new X-ray pinhole camera for energy dispersive X-ray fluorescence imaging with high-energy and high-spatial resolution  

NASA Astrophysics Data System (ADS)

A new X-ray pinhole camera for the Energy Dispersive X-ray Fluorescence (ED-XRF) imaging of materials with high-energy and high-spatial resolution, was designed and developed. It consists of a back-illuminated and deep depleted CCD detector (composed of 1024 × 1024 pixels with a lateral size of 13 ?m) coupled to a 70 ?m laser-drilled pinhole-collimator, positioned between the sample under analysis and the CCD. The X-ray pinhole camera works in a coaxial geometry allowing a wide range of magnification values. The characteristic X-ray fluorescence is induced on the samples by irradiation with an external X-ray tube working at a maximum power of 100 W (50 kV and 2 mA operating conditions). The spectroscopic capabilities of the X-ray pinhole camera were accurately investigated. Energy response and energy calibration of the CCD detector were determined by irradiating pure target-materials emitting characteristic X-rays in the energy working-domain of the system (between 3 keV and 30 keV). Measurements were performed by using a multi-frame acquisition in single-photon counting. The characteristic X-ray spectra were obtained by an automated processing of the acquired images. The energy resolution measured at the Fe-K? line is 157 eV. The use of the X-ray pinhole camera for the 2D resolved elemental analysis was investigated by using reference-patterns of different materials and geometries. The possibility of the elemental mapping of samples up to an area of 3 × 3 cm2 was demonstrated. Finally, the spatial resolution of the pinhole camera was measured by analyzing the profile function of a sharp-edge. The spatial resolution determined at the magnification values of 3.2 × and 0.8 × (used as testing values) is about 90 ?m and 190 ?m respectively.

Romano, F. P.; Altana, C.; Cosentino, L.; Celona, L.; Gammino, S.; Mascali, D.; Pappalardo, L.; Rizzo, F.

2013-08-01

226

A Laboratory-Scale Coaxial Fluorescence and Soft X-ray Microscope for Biological Observation  

NASA Astrophysics Data System (ADS)

A laboratory-scale coaxial fluorescence and soft x-ray microscope for biological observation was developed. The characteristic features of a fluorescence microscope were introduced to the conventional soft x-ray microscope, which was developed in our previous study, where the specimens can be set in air. One of the technical difficulties in detecting visible fluorescence is the chromatic aberration. This was overcome by applying a reflective optics, Wolter mirror, to the coaxial optical system. The coaxial optical system offers experimental simplicity and makes it possible to obtain soft x-ray images and fluorescence images of an identical specimen, which can be more informative than applying either imaging modality alone. Therefore, the newly developed optical system offers high-quality structural and morphological details of biological specimens with the ability to localize specific cells and other important sub-cellular targets. Soft x-ray images and fluorescence images of an identical DNA, which were derived from redfish testes and stained with DAPI (4', 6-diamidino-2-phenylindole), were obtained by the newly developed coaxial optical system.

Takaba, K.; Aoki, S.

2011-09-01

227

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

SciTech Connect

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.

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

2009-01-01

228

Neutron and synchrotron X-ray scattering experiments on actinides  

NASA Astrophysics Data System (ADS)

The proximity of the 5f bands to EF in U, Np and Pu has the consequence that hybridization between the 5f and conduction electron states usually occurs in metallic compounds containing these elements. Neutron experiments with polarized neutrons have been successful in measuring the ratio of the orbital to spin moments at the actinide site in compounds such as UFe2, NpCo2 and PuFe2, and this is found to be a sensitive measure of the hybridization. Anisotropic effects are found in the hexagonal system URhAl. A new technique measuring magnetic X-ray scattering with the energy tuned to the MIV and MV resonances at a synchrotron source is particularly well adapted for studies of the actinides. Experiments on U and Np compounds are discussed.

Lander, G. H.

1993-05-01

229

Total x-ray power improvement on recent wire array experiments on the Z machine.  

SciTech Connect

Recent experiments on the refurbished Z-machine were conducted using large diameter stainless steel arrays which produced x-ray powers of 260 TW. Follow-up experiments were then conducted utilizing tungsten wires with approximately the same total mass with the hypothesis that the total x-ray power would increase. On the large diameter tungsten experiments, the x-ray power averaged over 300 TW and the total x-ray energy was greater than 2MJ. Different analysis techniques for inferring the x-ray power will be described in detail.

Jennings, Christopher A.; Ampleford, David J.; Porter, John Larry, Jr.; Cuneo, Michael Edward; Savage, Mark Edward; Rochau, Gregory Alan; Lopez, Mike R.; Jones, Brent Manley; Jones, Michael C.

2010-11-01

230

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

SciTech Connect

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.

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

231

In situ system for X-ray absorption spectroscopy experiments to investigate nanoparticle crystallization.  

PubMed

A new furnace, based on a halogen lamp, and a sample cell have been designed and constructed for in situ X-ray absorption spectroscopy experiments in conventional and dispersive mode (transmission and fluorescence geometries). The main application of the apparatus is thermal treatment studies under controlled conditions for dynamical processes. The sol-gel (gelatin) method has been utilized to synthesize NiO nanoparticles. During this heating process, in situ Ni K-edge X-ray absorption near-edge structural measurements provided evidence of the evolution of a Ni environment until complete NiO nanoparticle crystallization. This case is reported in order to show the furnace performance in dispersive mode. PMID:17057324

Meneses, C T; Flores, W H; Sotero, A P; Tamura, E; Garcia, F; Sasaki, J M

2006-10-18

232

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

Microsoft Academic Search

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

G. Budak; A Karabulut

1999-01-01

233

Multielement Analysis of Aerosols by X-Ray Fluorescence with Total-Reflection Sample Carrier.  

National Technical Information Service (NTIS)

With the help of a new type of energy-dispersive X-ray fluorescence spectrometer, where exciting radiation incides on sample holders of polished quartz glass at such a small angle that it is totally reflected, a dust filter sample has been analyzed in the...

K. Freitag J. Knoth H. Schwenke

1979-01-01

234

Chemical composition and heterogeneity of Wild 2 cometary particles determined by synchrotron X-ray fluorescence  

Microsoft Academic Search

Seven cometary dust particle tracks in Stardust aerogel were studied using synchrotron X-ray fluorescence methods at the National Synchrotron Light Source (NY) and Advanced Photon Source (IL). Elemental maps were produced for each of the tracks and elemental abundances for 156 individual fragments within these tracks were determined. Whole-track elemental abundances were inferred by summing the elemental masses for the

A. Lanzirotti; S. R. Sutton; G. J. Flynn; M. Newville; W. Rao

2008-01-01

235

The In Viva Measurement of Trace Heavy Metals by K X-Ray Fluorescence  

Microsoft Academic Search

K x-ray fluorescence (K XRF) has become a well established technique for the non-invasive in vivo measurement of many trace toxic elements. There are particular difficulties associated with in vivo XRF elemental analysis; measurements are limited by dose and time and the human body is a low atomic number elemental matrix which results in a large scattering background. However, this

Fiona E. McNeil; Joanne M. O'Meara

236

Effect of the sample matrix on measurement uncertainty in X-ray fluorescence analysis  

Microsoft Academic Search

The estimation of measurement uncertainty, with reference to univariate calibration functions, is discussed in detail in the Eurachem Guide “Quantifying Uncertainty in Analytical Measurement”. The adoption of these recommendations to quantitative X-ray fluorescence analysis (XRF) involves basic problems which are above all due to the strong influence of the sample matrix on the analytical response. In XRF-analysis, the proposed recommendations

P. Morgenstern; L. Brüggemann; R. Wennrich

2005-01-01

237

The capabilities of total reflection X-ray fluorescence in the polymeric analytical field  

Microsoft Academic Search

This paper presents the capabilities of total reflection X-ray fluorescence (TXRF) as analytical technique specially focused in high-viscosity polymer dispersions. Appropriate sample preparation procedures are described taking into account the time stability of these dispersions. Special remarks considering different ways for drying samples in order to obtain the most uniform deposited film are investigated focusing on the behavior of aqueous

Cristina Vázquez

2004-01-01

238

Internal elemental microanalysis combining x-ray fluorescence, Compton and transmission tomography  

Microsoft Academic Search

Conventional x-ray transmission tomography provides the spatial distribution of the absorption coefficient inside a sample. Other tomographic techniques, based on the detection of photons coming from fluorescent emission, Compton and Rayleigh scattering, are used for obtaining information on the internal elemental composition of the sample. However, the reconstruction problem for these techniques is generally much more difficult than that of

Bruno Golosio; Alexandre Simionovici; Andrea Somogyi; Laurence Lemelle; Marina Chukalina; Antonio Brunetti

2003-01-01

239

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

ERIC Educational Resources Information Center

|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.…

Palmer, Peter T.

2011-01-01

240

Handheld modern computer brings new features to portable X-ray fluorescence coating thickness measurement device  

NASA Astrophysics Data System (ADS)

X-ray fluorescence is routinely used to measure coating thickness on table top setup. The use of a handheld modern computer (PC compatible) gives the possibility to build a portable device with new features. The computer is used to control device's components and to do processor consuming calculation. The user interface is “push button” to allow the utilization by nonspecialized operator.

Carapelle, Alain; Defise, Jean-Marc; Strivay, David; Garnir, Henri-Pierre

2011-06-01

241

Detection of Fingerprints Based on Elemental Composition Using Micro-X-Ray Fluorescence  

Microsoft Academic Search

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

C. G. Worley; S. Wiltshire; T. C. Miller; G. J. Havrilla; V. Majidi

2005-01-01

242

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

Microsoft Academic Search

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

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

2003-01-01

243

Determination of trace elements in uranium oxide by Total Reflection X-ray Fluorescence spectrometry  

NASA Astrophysics Data System (ADS)

A study on the applicability of Total Reflection X-ray Fluorescence for the determination of multielements in trace amounts in U3O8 matrix has been made. The calibration of the Total Reflection X-ray Fluorescence spectrometer and the validation of the method were done using multielement standards. The trace elements present in U3O8 standards and samples were determined after separating the U matrix by solvent extraction using tri-n-butyl phosphate and trioctyl phosphine oxide as extractants. From the aqueous phase the elements K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Rb, Sr, Y, Zr, Pb and Ba, etc., were determined by Total Reflection X-ray Fluorescence using Ga as an internal standard. An intercomparison of the Total Reflection X-ray Fluorescence determined concentrations of the trace elements specific to nuclear fuel, e.g. Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn in U3O8 standards/samples with certified concentrations for these elements in U3O8 standards and Inductively Coupled Plasma Atomic Emission Spectroscopy determined concentrations in real U3O8 samples was also made. The method shows a precision and accuracy better than 5% (1?) for most elements in concentration range of ng/mL with a sample size of 10 ?L.

Misra, N. L.; Singh Mudher, K. D.; Adya, V. C.; Rajeswari, B.; Venugopal, V.

2005-07-01

244

Study of air pollutants in Hong Kong using energy dispersive X-ray fluorescence  

Microsoft Academic Search

Airborne particulate samples were collected from various reference sites in Hong Kong and the energy dispersive X-ray fluorescence (EDXRF) intensities for 19 chemical elements were recorded. Principal component analysis (PCA) was employed so that the variances of these 19 original variables were captured by a few new indices called principal components or PCs. Data points for similar sources were automatically

A. K. M. Chu; H. H. Cheng; R. C. W. Kwok; K. N. Yu

2003-01-01

245

THE DEVELOPMENT OF POTENTIAL THIN STANDARDS FOR CALIBRATION OF X-RAY FLUORESCENCE SPECTROMETRY  

EPA Science Inventory

Thin films containing known concentrations of metals are important for the calibration of X-ray Fluorescence Spectrometry (XRF), especially for the analysis of collected airborne particulate matter. A focused ion-beam sputtering technique has been investigated as a candidate meth...

246

Algorithms for a hand-held miniature x-ray fluorescence analytical instrument  

Microsoft Academic Search

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

W. T. Elam; D. Newman; F. Ziemba

1998-01-01

247

Implementation of X-ray Fluorescence Microscopy for Investigation of Elemental Abnormalities in Amyotrophic Lateral Sclerosis  

Microsoft Academic Search

The abnormalities of metallochemical reactions may contribute to the pathogenesis of Amyotrophic Lateral Sclerosis (ALS). In the present work, an investigation of the elemental composition of the gray matter, nerve cells and white matter from spinal cord tissues representing three ALS cases and five non-ALS controls was performed. This was done with the use of the synchrotron microbeam X-ray fluorescence

B. Tomik; J. Chwiej; M. Szczerbowska-Boruchowska; M. Lankosz; S. Wójcik; D. Adamek; G. Falkenberg; S. Bohic; A. Simionovici; Z. Stegowski; A. Szczudlik

2006-01-01

248

Mössbauer and X-ray fluorescence measurements of authentic and counterfeited banknote pigments  

Microsoft Academic Search

Mössbauer and X-ray fluorescence studies revealed that a number of valuable monetary units (dollars, pounds, yen, old German marks, and others) are printed using pigments which contain considerable amounts of iron. Mössbauer spectroscopy has been applied to the analysis of the pigments that are used in both authentic and counterfeit currency notes.

V. Rusanov; K. Chakarova; H. Winkler; A. X. Trautwein

2009-01-01

249

Determination of Fe and Zn in healing plants by radionuclide X-ray fluorescence analysis  

Microsoft Academic Search

Radionuclide X-ray fluorescence method was used for the determination of Fe and Zn in healing plants (Sage, Peppermint, Stinging,\\u000a Common Agrimony, Milfoil, Ribwort, Tansy, White Dead-Nettle).238Pu exciting source and Si\\/Li semiconductor detector were used for the determination.

M. Harangozó; J. Tölgyessy; O. Tome?ek; I. Ruži?ka; K. Cejpek

1999-01-01

250

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

NASA Astrophysics Data System (ADS)

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.

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

2007-01-01

251

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...

252

The use of a mercuric iodide detector for X-ray fluorescence analysis in archaeometry  

NASA Astrophysics Data System (ADS)

For about two decades, energy dispersive X-ray fluorescence (EDXRF) has been employed in Rome for the analysis of works of art. A short history of the applications of EDXRF to paintings and alloys is presented. Finally, the usefulness of mercuric iodide room-temperature semiconductor detectors in this field is shown.

Cesareo, R.; Gigante, G. E.; Iwanczyk, J. S.; Dabrowski, A.

1992-11-01

253

Comparison of SR-excited X-ray fluorescence analysis with neutron activation analysis for hair and fiber  

Microsoft Academic Search

Human scalp hair and some kinds of vegetable and animal fibers were analyzed by means of the SR excited X-ray fluorescence\\u000a method (SRXFA) and the neutron activation method (NAA). Human hair samples collected from five males and five females were\\u000a washed by the IAEA method prior to analysis. In the SRXFA analysis, samples were excited by monochromated X-rays. Fluorescence\\u000a X-rays

Naoki Saitoh; Takao Suzuki; Tohru Kishi; Atsuo Iida; Yohichi Gohshi

1987-01-01

254

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

SciTech Connect

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.

Wang, Xin [Univ. of California, Davis, CA (United States). Dept. of Applied Science]|[Lawrence Berkeley National Lab., CA (United States)

1996-12-01

255

Beam line for experiments with coherent soft x-rays  

SciTech Connect

The advantages of coherent soft x-rays for three-dimensional imaging of biological specimens are discussed, the x-ray source requirements are described, and the general design of the beam line and its optical system are given. (WHK)

Howells, M.R.; Kirz, J.; Krinsky, S.

1982-12-01

256

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

SciTech Connect

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.

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

2006-10-29

257

MESSENGER detection of electron-induced X-ray fluorescence from Mercury's surface  

NASA Astrophysics Data System (ADS)

The X-Ray Spectrometer (XRS) on 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 XRS began orbital observations on 23 March 2011 and has observed X-ray fluorescence (XRF) from the surface of the planet whenever a sunlit portion of Mercury has been within the XRS field of view. Solar flares are generally required to provide sufficient signal to detect elements that fluoresce at energies above ˜2 keV, but XRF up to the calcium 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. Many such events have been detected and are identified as electron-induced X-ray emission produced by the interaction of ˜1-10 keV electrons with Mercury's surface. Electrons in this energy range were detected by the XRS during the three Mercury flybys and have also been observed regularly in orbit about Mercury. Knowledge of the energy spectrum of the electrons precipitating at the planet's surface makes it possible to infer surface composition from the measured fluorescent spectra, providing additional measurement opportunities for the XRS. Abundance results for Mg, Al, and Si are in good agreement with those derived from solar-induced XRF data, providing independent validation of the analysis methodologies. Derived S and Ca abundances are somewhat higher than derived from the solar-induced fluorescence data, possibly reflecting incomplete knowledge of the energy spectra of electrons impacting the planet.

Starr, Richard D.; Schriver, David; Nittler, Larry R.; Weider, Shoshana Z.; Byrne, Paul K.; Ho, George C.; Rhodes, Edgar A.; Schlemm, Charles E., II; Solomon, Sean C.; Trávní?ek, Pavel M.

2012-08-01

258

Application of Energy Dispersive X-Ray Fluorescence Spectroscopy to the Analysis of Contaminants in Fuels and Lubricants.  

National Technical Information Service (NTIS)

A rapid and inexpensive x-ray fluorescence spectroscopic method for the analysis of particulate contaminants has been developed. The method employs the collection of the particulates by filtration followed by x-ray fluorescence analysis of the filter. A u...

M. K. Greenberg F. M. Newman

1978-01-01

259

Elemental distribution images in prostate samples by X-ray fluorescence microtomography.  

PubMed

An X-ray transmission microtomography (CT) system combined with an X-ray fluorescence microtomography (XRF?CT) system was implemented in the Brazilian Synchrotron Light Laboratory (LNLS), in order to determine the elemental distribution in prostate samples aiming at establishing a correlation between the concentration of some elements and the characteristics and pathology of the tissues. The CT images were reconstructed using a filtered-back projection algorithm and the XRF?CT images were reconstructed using a filtered-back projection algorithm with absorption corrections. PMID:22206909

Pereira, G R; Rocha, H S; Anjos, M J; Lima, I; Lopes, R T

2011-12-17

260

Pulsed fluorescent x-ray system with on-line digitizer and data processor  

SciTech Connect

A pulsed source of monoenergetic x rays has been constructed for applications in which a narrow energy band and a short burst are both important. The radiation source is a high-purity, selectable foil that emits fluorescent x rays upon excitation by a bremsstrahlung pulse. A digitizer and a microcomputer are integrated into the system to aid operation and data processing. A general description, the more important system characteristics, and a few examples of applications are given. 7 references, 10 figures, 6 tables.

Berzins, G.J.; Valencia, J.E.; Gutierrez, J.W.; McGirt, F.; Moore, K.R.

1984-12-01

261

Radioisotope X-ray fluorescence analysis of some elements in colemanite ore  

NASA Astrophysics Data System (ADS)

The standard addition method for the determination of As, Sr, In, Sn, Sb, I, Cs and Ba elements in colemanite ore of Bigadiç region in the city of Balikesir (Turkey) was applied by using an Energy Dispersive X-ray Fluorescence (EDXRF) system. Samples are prepared from powder sifted by a 300-mesh sieve. An annular 100 mCi 241Am radioactive source emitting 59.5 keV photons was used for excitation. The characteristic K X-rays of the different elements were detected with a Si(Li) detector. These results are presented and discussed in this paper.

Karabulut, A.; Budak, G.

2000-01-01

262

A multiplatform code for the analysis of energy-dispersive X-ray fluorescence spectra  

NASA Astrophysics Data System (ADS)

A user friendly program for X-ray fluorescence analysis has been developed at the European Synchrotron Radiation Facility. The program allows interactive as well as batch processing of large data sets and it is particularly well suited for X-ray imaging. Its implementation of a complete description of the M shell is particularly helpful for analysis of data collected at low energies. The code is platform independent (Linux, Windows, MacOS X, Solaris …) and it is freely available for non-commercial use. Description of the algorithms used and practical examples are presented.

Solé, V. A.; Papillon, E.; Cotte, M.; Walter, Ph.; Susini, J.

2007-01-01

263

Hard X-ray Fluorescence Measurements of Heteroepitaxial Solid Oxide Fuel Cell Cathode Materials  

SciTech Connect

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).

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

264

Educational X-Ray Experiments and XRF Measurements with a Portable Setup Adapted for the Characterization of Cultural Heritage Objects  

ERIC Educational Resources Information Center

It is common to modify valuable, sophisticated equipment, originally acquired for other purposes, to adapt it for the needs of educational experiments, with great didactic effectiveness. The present project concerns a setup developed from components of a portable system for energy dispersive x-ray fluorescence spectroscopy (EDXRF). Two educational…

Sianoudis, I.; Drakaki, E.; Hein, A.

2010-01-01

265

Educational X-Ray Experiments and XRF Measurements with a Portable Setup Adapted for the Characterization of Cultural Heritage Objects  

ERIC Educational Resources Information Center

|It is common to modify valuable, sophisticated equipment, originally acquired for other purposes, to adapt it for the needs of educational experiments, with great didactic effectiveness. The present project concerns a setup developed from components of a portable system for energy dispersive x-ray fluorescence spectroscopy (EDXRF). Two…

Sianoudis, I.; Drakaki, E.; Hein, A.

2010-01-01

266

Optimizing Monocapillary Optics for Synchrotron X-ray Diffraction, Fluorescence Imaging, and Spectroscopy Applications  

SciTech Connect

A number of synchrotron x-ray applications such as powder diffraction in diamond anvil cells, microbeam protein crystallography, x-ray fluorescence imaging, etc. can benefit from using hollow glass monocapillary optics to improve the flux per square micron on a sample. We currently draw glass tubing into the desired elliptical shape so that only one-bounce under total reflection conditions is needed to bring the x-ray beam to a focus at a 25 to 50 mm distance beyond the capillary tip. For modest focal spot sizes of 10 to 20 microns, we can increase the intensity per square micron by factors of 10 to 1000. We show some of the results obtained at CHESS and Hasylab with capillaries focusing 5 to 40 keV radiation, their properties, and how even better the experimental results could be if more ideal capillaries were fabricated in the future.

Bilderback, Donald H.; Kazimirov, Alexander; Gillilan, Richard; Cornaby, Sterling; Woll, Arthur; Zha, Chang-Sheng [CHESS, Wilson Laboratory, Cornell University, Ithaca, New York, 14853 (United States); Huang Rong [Center for Advanced Radiation Sources, U. of Chicago, Chicago, Illinois, 60637 (United States)

2007-01-19

267

Determining yttrium in plutonium by anion-exchange x-ray fluorescence  

SciTech Connect

This report describes a method for determining yttrium in plutonium using an anion-exchange separation and x-ray fluorescence. We add zirconium to the plutonium solution as an internal standard. We oxidize the plutonium to Pu + 4 and pass the solution through an anion-exchange column with 8M HCl. The Pu + 4 sorbs to the resin and the yttrium and zirconium pass through completely. We evaporate the eluate solution containing the yttrium and zirconium and transfer it to a 10-ml volumetric flask. We add a portion of this solution to an x-ray cell and measure the Ka x-ray line for both yttrium and zirconium. The ratio of yttrium to zirconium is then compared with standards. This method has a precision of 0.84% relative standard deviation for yttrium over a concentration range of 0.5 to 3.5 mg in a 10-ml volume. 1 ref., 2 figs., 2 tabs.

Martell, C.J.; Hansel, J.M.

1985-11-01

268

Phase-resolved x-ray ferromagnetic resonance measurements in fluorescence yield  

NASA Astrophysics Data System (ADS)

Phase-resolved x-ray ferromagnetic resonance (XFMR) has been measured in fluorescence yield, extending the application of XFMR to opaque samples on opaque substrates. Magnetization dynamics were excited in a Co50Fe50(0.7)/Ni90Fe10(5) bilayer by means of a continuous wave microwave excitation, while x-ray magnetic circular dichroism (XMCD) spectra were measured stroboscopically at different points in the precession cycle. By tuning the x-ray energy to the L3 edges of Ni and Fe, the dependence of the real and imaginary components of the element specific magnetic susceptibility on the strength of an externally applied static bias field was determined. First results from measurements on a Co50Fe50(0.7)/Ni90Fe10(5)/Dy(1) sample confirm that enhanced damping results from the addition of the Dy cap.

Marcham, M. K.; Keatley, P. S.; Neudert, A.; Hicken, R. J.; Cavill, S. A.; Shelford, L. R.; van der Laan, G.; Telling, N. D.; Childress, J. R.; Katine, J. A.; Shafer, P.; Arenholz, E.

2011-04-01

269

X-ray emission from the outer planets: Albedo for scattering and fluorescence of solar X rays  

Microsoft Academic Search

Soft X-ray emission has been observed from the low-latitude “disk” of both Jupiter and Saturn as well as from the auroral regions of these planets. The disk emission as observed by ROSAT, the Chandra X-Ray Observatory, and XMM-Newton appears to be uniformly distributed across the disk and to be correlated with solar activity. These characteristics suggest that the disk X

T. E. Cravens; J. Clark; A. Bhardwaj; R. Elsner; J. H. Waite Jr; A. N. Maurellis; G. R. Gladstone; G. Branduardi-Raymont

2006-01-01

270

X-ray fluorescence from the element with atomic number Z=120.  

PubMed

An atomic clock based on x-ray fluorescence yields has been used to estimate the mean characteristic time for fusion followed by fission in reactions 238U + 64Ni at 6.6??MeV/A. Inner shell vacancies are created during the collisions in the electronic structure of the possibly formed Z=120 compound nuclei. The filling of these vacancies accompanied by a x-ray emission with energies characteristic of Z=120 can take place only if the atomic transitions occur before nuclear fission. Therefore, the x-ray yield characteristic of the united atom with 120 protons is strongly related to the fission time and to the vacancy lifetimes. K x rays from the element with Z=120 have been unambiguously identified from a coupled analysis of the involved nuclear reaction mechanisms and of the measured photon spectra. A minimum mean fission time ?(f)=2.5×10(-18)??s has been deduced for Z=120 from the measured x-ray multiplicity. PMID:22540578

Frégeau, M O; Jacquet, D; Morjean, M; Bonnet, E; Chbihi, A; Frankland, J D; Rivet, M F; Tassan-Got, L; Dechery, F; Drouart, A; Nalpas, L; Ledoux, X; Parlog, M; Ciortea, C; Dumitriu, D; Fluerasu, D; Gugiu, M; Gramegna, F; Kravchuk, V L; Marchi, T; Fabris, D; Corsi, A; Barlini, S

2012-03-19

271

X-Ray Fluorescence from the Element with Atomic Number Z=120  

NASA Astrophysics Data System (ADS)

An atomic clock based on x-ray fluorescence yields has been used to estimate the mean characteristic time for fusion followed by fission in reactions U238+Ni64 at 6.6MeV/A. Inner shell vacancies are created during the collisions in the electronic structure of the possibly formed Z=120 compound nuclei. The filling of these vacancies accompanied by a x-ray emission with energies characteristic of Z=120 can take place only if the atomic transitions occur before nuclear fission. Therefore, the x-ray yield characteristic of the united atom with 120 protons is strongly related to the fission time and to the vacancy lifetimes. K x rays from the element with Z=120 have been unambiguously identified from a coupled analysis of the involved nuclear reaction mechanisms and of the measured photon spectra. A minimum mean fission time ?f=2.5×10-18s has been deduced for Z=120 from the measured x-ray multiplicity.

Frégeau, M. O.; Jacquet, D.; Morjean, M.; Bonnet, E.; Chbihi, A.; Frankland, J. D.; Rivet, M. F.; Tassan-Got, L.; Dechery, F.; Drouart, A.; Nalpas, L.; Ledoux, X.; Parlog, M.; Ciortea, C.; Dumitriu, D.; Fluerasu, D.; Gugiu, M.; Gramegna, F.; Kravchuk, V. L.; Marchi, T.; Fabris, D.; Corsi, A.; Barlini, S.

2012-03-01

272

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...

273

Sub-Picosecond Tunable Hard X-Ray Undulator Source for Laser/X-Ray Pump-Probe Experiments  

SciTech Connect

The FEMTO source under construction at the {mu}XAS beamline is designed to enable tunable time-resolved laser/x-ray absorption and diffraction experiments in photochemistry and condensed matter with ps- and sub-ps resolution. The design takes advantage of (1) the highly stable operation of the SLS storage ring, (2) the reliable high harmonic operation of small gap, short period undulators to generate hard x-rays with energy 3-18 keV at 2.4 GeV beam energy, and (3) the progress in high power, high repetition rate fs solid-state laser technology to employ laser/e-beam 'slicing' to reach a time resolution of ultimately 100 fs. The source will profit from the inherently synchronized pump (laser I: 100 fs, 2 mJ, 1 kHz) and probe (sliced X-rays, laser II: 50 fs, 5 mJ, 1 kHz) pulses, and from the excellent stability of the SLS storage ring which is operated in top-up mode and controlled by a fast orbit feedback (FOFB). Coherent radiation emitted at THz frequencies by the sliced 100 fs electron bunches will be monitored as on-line cross-correlation signal to keep the laser-electron beam interaction at optimum. The source is designed to provide at 8 keV (100 fs) a monochromized flux of 104 ph/s/0.01% bw (Si crystal monochromator) and 106 ph/s/1.5% bw (multilayer monochromator) at the sample. It is operated in parasitic mode using a hybrid bunch filling pattern. Because of the low intensity measurements are carried out repetitively over many shots using refreshing samples and gated detectors. 'Diffraction gating' experiments will be used to characterize the sub-ps X-ray pulses.

Ingold, G.; Beaud, P.; Johnson, S.; Streun, A.; Schmidt, T.; Abela, R.; Al-Adwan, A.; Abramsohn, D.; Boege, M.; Grolimund, D.; Keller, A.; Krasniqi, F.; Rivkin, L.; Rohrer, M.; Schilcher, T.; Schmidt, T.; Schlott, V.; Schulz, L.; Veen, F. van der; Zimoch, D. [Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen (Switzerland)

2007-01-19

274

Sub-Picosecond Tunable Hard X-Ray Undulator Source for Laser/X-Ray Pump-Probe Experiments  

NASA Astrophysics Data System (ADS)

The FEMTO source under construction at the ?XAS beamline is designed to enable tunable time-resolved laser/x-ray absorption and diffraction experiments in photochemistry and condensed matter with ps- and sub-ps resolution. The design takes advantage of (1) the highly stable operation of the SLS storage ring, (2) the reliable high harmonic operation of small gap, short period undulators to generate hard x-rays with energy 3-18 keV at 2.4 GeV beam energy, and (3) the progress in high power, high repetition rate fs solid-state laser technology to employ laser/e-beam `slicing' to reach a time resolution of ultimately 100 fs. The source will profit from the inherently synchronized pump (laser I: 100 fs, 2 mJ, 1 kHz) and probe (sliced X-rays, laser II: 50 fs, 5 mJ, 1 kHz) pulses, and from the excellent stability of the SLS storage ring which is operated in top-up mode and controlled by a fast orbit feedback (FOFB). Coherent radiation emitted at THz frequencies by the sliced 100 fs electron bunches will be monitored as on-line cross-correlation signal to keep the laser-electron beam interaction at optimum. The source is designed to provide at 8 keV (100 fs) a monochromized flux of 104 ph/s/0.01% bw (Si crystal monochromator) and 106 ph/s/1.5% bw (multilayer monochromator) at the sample. It is operated in parasitic mode using a hybrid bunch filling pattern. Because of the low intensity measurements are carried out repetitively over many shots using refreshing samples and gated detectors. `Diffraction gating' experiments will be used to characterize the sub-ps X-ray pulses.

Ingold, G.; Beaud, P.; Johnson, S.; Streun, A.; Schmidt, T.; Abela, R.; Al-Adwan, A.; Abramsohn, D.; Böge, M.; Grolimund, D.; Keller, A.; Krasniqi, F.; Rivkin, L.; Rohrer, M.; Schilcher, T.; Schmidt, T.; Schlott, V.; Schulz, L.; van der Veen, F.; Zimoch, D.

2007-01-01

275

Sulfur abundance of asteroid 25143 Itokawa observed by X-ray fluorescence spectrometer onboard Hayabusa  

NASA Astrophysics Data System (ADS)

The Japanese Hayabusa spacecraft successfully carried out in situ observations of S-class asteroid 25143 Itokawa, including the surface major elemental analysis with the X-ray fluorescence spectrometer (XRS-Hayabusa). Our previous results for the X-ray experiments (Okada et al., 2006a) indicated that major elemental ratios of Mg/Si and Al/Si on the surface of Itokawa resemble ordinary LL- or L-chondrites more than any other meteorite analogues. In the NEAR Shoemaker observations of S-class asteroid 433 Eros, the results of X-ray fluorescence observations indicated the depletion of sulfur, probably reflecting impact-induced volatilization, photo- or ion-induced sputtering at the surface, or the loss of FeS-rich materials due to partial melting. Here, we determined the elemental abundance of sulfur (S) on the surface of Itokawa, in addition to that of Mg, Al, and Si, and its regional variation using XRS-Hayabusa observations. In particular, we carefully corrected the fluctuation of solar X-rays, variation of surface geometry, and sensor response function in this analysis, and thus we believe that the results are more accurate than those of our previous report. In this study, the upper and lower limits for Mg/Si, Al/Si, and S/Si overlap those of meteorite analogues for ordinary chondrites or primitive achondrites. In terms of the major elemental composition, Itokawa is best classified as a ordinary chondrite or a primitive achondrite. Our models do not include the mineral mixing effects. With the effects, the abundance of sulfur is expected to be 30% lower than our results. Hence, we conclude that the abundance of sulfur on the surface of Itokawa is almost equal to or even lower than the average abundance in ordinary chondrites. Although the abundances for Mg and Si are globally homogeneous, best-fit or upper limits of mass fraction for Al and S vary in local areas. There is a negative correlation (-0.92) for Al/Si vs. S/Si in ten facets. In particular, the area with the lowest sulfur, accompanied with enriched aluminum, is found in Arcoona, close to a cratered area. Therefore, aluminum enrichment and sulfur depletion features may support events of partial melting on the parent body of Itokawa or aluminum-rich material impacts on the surface of Itokawa. In some areas, Itokawa has a brighter geometric albedo and color variation. Little altered, fresh material may be exposed in these portions of the surface. The sulfur abundance on the surface appears to vary between little and highly altered areas by space weathering. Thus, the sulfur regional variation in our result may reflect the heterogeneity of a surface altered by space weathering.

Arai, T.; Okada, T.; Yamamoto, Y.; Ogawa, K.; Shirai, K.; Kato, M.

2008-01-01

276

The Solar-A soft X-ray telescope experiment  

Microsoft Academic Search

The Japanese Solar-A mission for the study of high energy solar physics is timed to observe the sun during the next activity maximum. This small spacecraft includes a carefully coordinated complement of instruments for flare studies. In particular, the soft X-ray telescope (SXT) will provide X-ray images of flares with higher sensitivity and time resolution than have been available before.

L. Acton; M. Bruner; W. Brown; J. Lemen; T. Hirayama

1988-01-01

277

Hair mineral analysis by X-ray fluorescence spectrometry: associations with body fat.  

PubMed

Hair mineral analysis using an X-ray fluorescence spectrometer as a method of estimating body fat percentage (BF%) was investigated. Body fat percentage of 24 healthy Japanese, aged 20-27 years, was measured using a hand-held impedance analyzer (BF%IMP). X-ray (K?-ray) intensities of sulfur, chlorine, potassium, calcium, titanium, and iron (Fe) in hair were measured using an X-ray fluorescence spectrometer. Body fat percentage was also measured using a Hologic whole body dual energy X-ray absorptiometer (BF%DXA) in nine subjects selected from the above 24 subjects based on their BF%IMP. Correlations of the two BF%s with Fe-K? were significant (BFIMP: r = 0.60 n = 24, p<0.01; BFDXA: r = 0.67 n = 9, p<0.05). The mean (ąSD) biases (measured minus estimated using multiple regression equations by Fe-K?) for BF%IMP and BF%DXA were 2.97 ą 2.25% and 1.77 ą 1.33%, respectively. The SEEs for the two equations for BF%IMP and for BF%DXA were less than 4%. These results suggest that Fe-K? may be a predictor of body fat percentage. However, the subjects were few and only Japanese in their twenties, so that further investigation is needed for methodological generalization. PMID:23635370

Uetake, Katsuji; Tanaka, Toshio

2013-01-01

278

X-ray spectral diagnostics of neon photoionization experiments on the Z-machine  

Microsoft Academic Search

We report on an initial spectroscopic study of low-density, x-ray photoionized neon with x-ray spectroscopy. These experiments, carried out on the Z-machine at Sandia, are optimized to produce a gradient-free, collisionless plasma, and to explore issues related to the rapid x-ray photoionization of relatively cold, low-density plasmas. The initial experiments used time-integrated absorption spectroscopy, backlit by the pinch radiation, to

David H. Cohen; Joseph J. Macfarlane; James E. Bailey; Duane A. Liedahl

2003-01-01

279

X-ray spectral diagnostics of neon photoionization experiments on the z- machine  

Microsoft Academic Search

We report on an initial spectroscopic study of low-density, x-ray photoionized neon with x ray spectroscopy. These experiments, carried out on the Z-machine at Sandia, are optimized to produce a gradient free, collisionless plasma, and to explore issues related to the rapid x-ray photoionization of relatively cold, low-density plasmas. The initial experiments used time-integrated absorption spectroscopy, backlit by the pinch

David H. Cohen; Joseph J. MacFarlane; James E. Bailey; Duane A. Liedahl

280

X-ray Absorption Fine Structure Combined with X-ray Fluorescence Spectrometry. Improvement of Spectral Resolution at the Absorption Edges of 9?29 keV  

Microsoft Academic Search

X-ray absorption near-edge structure (XANES) suffers from core-hole lifetime broadening at a higher energy absorption edge, such as Sn K (29 keV, ĄK ) 8.49 eV). To overcome this problem, emitted Sn Kr1 fluorescence from sample was counted using high-energy-resolution fluorescence spectrometer in the XANES measurements. Experimental energy resolution (5.0 eV) was consistent with theoretical values based on the Rowland

Yasuo Izumi; Hiroyasu Nagamori; Fumitaka Kiyotaki; Dilshad Masih; Taketoshi Minato; Eric Roisin; Jean-Pierre Candy; Hajime Tanida; Tomoya Uruga

2005-01-01

281

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

NASA Astrophysics Data System (ADS)

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.

Zhu, Ying; Bewer, Brian; Zhang, Honglin; Nichol, Helen; Thomlinson, Bill; Chapman, Dean

2010-06-01

282

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

SciTech Connect

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.

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

283

Application of in situ x-ray absorption and fluorescence measurements to analyze solutions in a simulated pit  

SciTech Connect

X-ray energy-dispersive spectroscopy has been used to study the compositions of metal ions in solutions developed during localized corrosion. An electrochemical cell was designed to simulate a corrosion pit, maintaining one-dimensional diffusion and fulfilling the requirements for x-ray fluorescence measurements. The working electrode consisted of a dissolving thin foil of Type 304 stainless steel sealed between Mylar sheets through which the x-ray beam passed. Concentration gradients within the artificial pit were quantitatively determined.

Isaacs, H.S.; Davenport, A.J.; Cho, J.H. (Brookhaven National Lab., Upton, NY (United States)); Rivers, M.L.; Sutton, S.R. (Chicago Univ., IL (United States). Dept. of Geophysical Sciences)

1991-01-01

284

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

NASA Astrophysics Data System (ADS)

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.

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

2012-07-01

285

Application of the X-ray fluorescence analysis and X-ray diffraction in geochemical studies of the Pleistocene tills from Holy Cross Mountains  

NASA Astrophysics Data System (ADS)

X-ray fluorescence analysis methods (wavelength dispersive X-ray fluorescence analysis (WDXRF) and total reflection X-ray fluorescence (TXRF)) and X-ray powder diffraction (XRPD) have been applied in complementary geochemical studies of the Pleistocene till samples. The XRPD technique gave information about the mineral composition of the analyzed samples while the WDXRF and TXRF studies allowed the fast elemental analysis. The till samples were collected from different regions of Holy Cross Mountains (located in central Poland) which are still not unambiguously described in the context of the geochemical studies of the Quaternary sediments. The analysis was concentrated on the geochemical composition of the till samples both for materials occurring on the surface (characterized by continuous weathering processes) and for samples taken from core borehole. The overriding purpose of these studies is determination of the local lithotype of the tills and its lithologic and petrographic diagnostic properties, including the chemical composition of clay and minerals found in the clay. In the presented work the experimental sets up, sample preparation procedure and measurements programme will be discussed in details. Finally, the elemental and mineral compositions will be presented for studied different groups of the samples.

Kubala-Kuku?, A.; Ludwikowska-K?dzia, M.; Bana?, D.; Braziewicz, J.; Majewska, U.; Pajek, M.; Wudarczyk-Mo?ko, J.

2013-12-01

286

Internal elemental imaging by scanning X-ray fluorescence microtomography at the hard X-ray microprobe beamline of the SSRF: Preliminary experimental results  

NASA Astrophysics Data System (ADS)

Synchrotron-based X-ray micro-fluorescence (?-SXRF) is a non-destructive analytical technique and has been widely used to detect and quantify the elemental composition of samples in their natural state. To determine the internal elemental distributions within samples, X-ray fluorescence microtomography has been developed based on the hard X-ray microprobe at beamline BL15U1 of the Shanghai Synchrotron Radiation Facility (SSRF) in Shanghai, China. This technique was applied to image the cross-sectional distributions of multiple elements within a single human hair, and its validity was evaluated by comparing the results with the elemental maps of a thin hair section obtained using the well-established ?-SXRF mapping method. Elemental images of S, Ca, Mn, Fe, Cu, and Zn within a virtual slice of the hair were reconstructed after the tomographic measurements. The tomographic images of heavy elements like Fe, Cu, and Zn were found to be in good agreement with the corresponding ?-SXRF maps. Light elements, such as S, however, represented different patterns due to non-negligible self-absorption in the sample, and sophisticated correction algorithms accounting for such effects are required for obtaining qualitatively and quantitatively more accurate images. Compared to ?-SXRF mapping, X-ray fluorescence microtomography reduces the sample preparation requirements and has been demonstrated in this work as being a more ideal and effective imaging modality to non-destructively mapping out the internal distribution of heavy elements within samples at the micrometer scale at the SSRF.

Qiu, Jingke; Deng, Biao; Yang, Qun; Yan, Fen; Li, Aiguo; Yu, Xiaohan

2011-11-01

287

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

NASA Astrophysics Data System (ADS)

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.

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

2008-12-01

288

X-ray fluorescence/Auger-electron coincidence spectroscopy of vacancy cascades in atomic argon  

SciTech Connect

Argon L{sub 2.3}-M{sub 2.3}M{sub 2.3} Auger-electron spectra were measured in coincidence with K{alpha} fluorescent x-rays in studies of Ar K-shell vacancy decays at several photon energies above the K-threshold and on the 1s-4p resonance in atomic argon. The complex spectra recorded by conventional electron spectroscopy are greatly simplified when recorded in coincidence with fluorescent x-rays, allowing a more detailed analysis of the vacancy cascade process. The resulting coincidence spectra are compared with Hartree-Fock calculations which include shake-up transitions in the resonant case. Small energy shifts of the coincidence electron spectra are attributed to post-collision interaction with 1s photoelectrons.

Arp, U. [National Inst. of Standards and Technology, Gaithersburg, MD (United States). Electron and Optical Physics Div.; LeBrun, T.; Southworth, S.H.; Jung, M. [Argonne National Lab., IL (United States). Physics Div.; MacDonald, M.A. [E.P.S.R.C. Daresbury Lab., Warrington (United Kingdom)

1996-12-01

289

A Review, Bibliography, and Tabulation of K, L, and Higher Atomic Shell X-Ray Fluorescence Yields  

Microsoft Academic Search

The K, L, and higher atomic shell x-ray fluorescence yield measured data, covering the period 1978 to 1993, following the major previous compilations by Bambynek etal. (1972) and Krause (1979), are reviewed. An annotated bibliography of x-ray fluorescence yield measurements, analyses, fits and tables 1978–1993 is presented. Comparisons of the fluorescence yields ?k, ?ŻL, and ?ŻM, based on measurements, and

J. H. Hubbell; P. N. Trehan; Nirmal Singh; B. Chand; D. Mehta; M. L. Garg; R. R. Garg; Surinder Singh; S. Puri

1994-01-01

290

Analysis of stainless steel samples by energy dispersive X-ray fluorescence (EDXRF) spectrometry  

Microsoft Academic Search

A simple method for the analysis of stainless steel samples is presented which is based on radioisotope excited energy dispersive\\u000a X-ray fluorescence (EDXRF) spectrometry and does not require any type-standards. Both absorption and enhancement effects have\\u000a been taken into account in the fundamental parameter method for quantitative analysis and an iterative approach is followed\\u000a for calculation of concentrations in steel

M. K. Tiwari; A. K. Singh; K. J. S. Sawhney

2001-01-01

291

Analysis of non-organic elements in plant foliage using polarised X-ray fluorescence spectrometry  

Microsoft Academic Search

An X-ray fluorescence (XRF) method for the rapid and non-destructive analysis of 30 non-organic elements in plant leaves over five orders of magnitude concentration from several percentage of dry weight to sub-milligram per kilogram, is described. There is a growing need for a simple method of monitoring non-organic trace elements in plant material, especially those which accumulate in soils with

W. E. Stephens; A. Calder

2004-01-01

292

A new method of depth sensitive micro-X-ray fluorescence analysis  

NASA Astrophysics Data System (ADS)

A new method to measure depth distributions of elements by micro-X-ray fluorescence analysis was developed. This method is based on the use of a focusing optical element and the knife-edge principle and gives depth resolutions of about 23 ?m. Furthermore, this method also allows measuring surface profiles with a depth resolution of 7 ?m. In this paper experimental results of depth distribution measurements of a layered sample and of the surface roughness profile of another sample are presented.

Bjeoumikhov, A.; Bjeoumikhova, S.; Wedell, R.; Gubzhokov, R.; Margushev, Z.

2006-07-01

293

Application limits in using backscattered radiation for matrix correction in X-ray fluorescence analysis  

Microsoft Academic Search

The known relations of sample element concentration to X-ray fluorescence and backscattered radiation and the correlated cross-sections\\u000a are investigated for atomic numbers between 6 and 92. Calculations were performed using tabulated coefficients. Results show\\u000a that coherent scattered primary radiation cannot be used as a check point for matrix correction. Only incoherent scattering\\u000a on well defined conditions makes it possible to

R. George; M. Schiekel

1983-01-01

294

Application of a high-resolution x-ray fluorescence analyzer  

Microsoft Academic Search

We have developed a high resolution x-ray fluorescence analyzer based on the principle of active optics. It combines a resolution of ca. 5 eV with a tunability over several keV and a wide solid-angle coverage (ca. 2 by 5 degrees). To date, this analyzer has been used in near-edge spectroscopy of gallium in GaAs, and for the detection and chemical

B. W. Adams; K. Attenkofer

2006-01-01

295

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

Microsoft Academic Search

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

Galina V. Pashkova

2009-01-01

296

Trends in hard X-ray fluorescence mapping: environmental applications in the age of fast detectors  

Microsoft Academic Search

Environmental samples are extremely diverse but share a tendency for heterogeneity and complexity. This heterogeneity poses\\u000a methodological challenges when investigating biogeochemical processes. In recent years, the development of analytical tools\\u000a capable of probing element distribution and speciation at the microscale have allowed this challenge to be addressed. Of these\\u000a available tools, laterally resolved synchrotron techniques such as X-ray fluorescence mapping

E. Lombi; M. D. de Jonge; E. Donner; C. G. Ryan; D. Paterson

2011-01-01

297

The Monte Carlo modelling of in vivo X-ray fluorescence measurement of lead in tissue  

Microsoft Academic Search

A Monte Carlo model has been developed, using the EGS4 code, to model the in vivo X-ray fluorescence (XRF) measurement of Pb in non-superficial bone\\/tissue. Unlike previous work in this field the current model incorporates a correction for Doppler broadening of the Compton scatter peak due to the electron momentum distribution of the medium (tissue\\/water) in which the photons are

J. D. Wallace

1994-01-01

298

Synchrotron X-ray Fluorescence Microtomography in Geo, Cosmo-, and Bio chemistry  

Microsoft Academic Search

Synchrotron-based X-ray fluorescence computed microtomography (xrfCMT) is a unique method for imaging major and trace element distributions within natural materials nondestructively and with high spatial resolution. The technique is particularly useful in imaging and quantifying elemental abundance in small objects that may be too precious or too difficult to section, or in the analysis of materials in which sectioning may

A. Lanzirotti; S. R. Sutton; M. Rivers; R. Tappero

2009-01-01

299

First X-ray Fluorescence MicroCT Results from Micrometeorites at SSRL  

Microsoft Academic Search

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

Konstantin Ignatyev; Kathy Huwig; Ralph Harvey; Hope Ishii; John Bradley; Katharina Luening; Sean Brennan; Piero Pianetta

2007-01-01

300

First X-ray Fluorescence MicroCT Results from Micrometeorites at SSRL  

Microsoft Academic Search

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

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

2006-01-01

301

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

Microsoft Academic Search

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

Benjamin S. Twining; Stephen B. Baines; Nicholas S. Fisher; Jörg Maser; Stefan Vogt; Chris Jacobsen; Antonio Tovar-Sanchez; S. A. Sanudo-Wihelmy

2003-01-01

302

Preliminary testing of a prototype portable x-ray fluorescence spectrometer. Information circular  

Microsoft Academic Search

The Federal Bureau of Mines participated with the National Aeronautics and Space Administration and Martin Marietta Aerospace in developing, building, and testing a portable X-ray fluorescence spectrometer for use as an analyzer in mineral-resource investigative work. 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

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

1982-01-01

303

ON THE SUITABILITY OF PORTABLE X-RAY FLUORESCENCE ANALYZERS FOR RAPID SCREENING OF TOXIC ELEMENTS  

Microsoft Academic Search

X-Ray Fluorescence spectrometry (XRF) has been routinely used for alloy testing, determination of Pb in paint, and determination of Cd in plastic. However, its use to screen for toxic elements in food and medicinal products has been surprisingly limited to date. While XRF is less sensitive than atomic spectrometry methods such as ICP-AES and ICP-MS, it offers a number of

Pete Palmer; Siri Webber; Kelly Ferguson

304

Development of micro X-ray fluorescence spectrometer with multi excitation sources  

Microsoft Academic Search

X-ray fluorescence analysis (XRF) is a suitable technique for elemental analysis in nondestructive measurement. Recently, small area analysis by using the XRF technique has gained popularity. The synchrotron radiation source is responsible for the increase in the popularity of micro-XRF analysis. However, most people find it difficult to gain access to the synchrotron radiation facility. In this study, a micro-XRF

Shuji Maeo; Ichiro Sakai; Kaori Kuzushita; Kazuo Taniguchi

2007-01-01

305

Evaluation of the uncertainties associated with in vivo X-ray fluorescence bone lead calibrations  

Microsoft Academic Search

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

Jeffrey C. Lodwick

2003-01-01

306

Preconcentration Methods for the Analysis of Liquid Samples by X-Ray Fluorescence Techniques  

Microsoft Academic Search

This article gives an overview of the state-of-the-art of multi-element and single-element preconcentration procedures prior to X-ray fluorescence (XRF) analysis of liquid samples. Many of these preconcentration methods were developed long ago and the purpose of this review is to present some new efficient variations of these methods and new techniques extending the possibilities of XRF for liquid solutions analysis.

E. Margui; R. van Grieken; C. Fontas; M. Hidalgo; I. Queralt

2010-01-01

307

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

Microsoft Academic Search

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

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

2007-01-01

308

Application of portable X-ray fluorescence analyses to metabasalt stratigraphy, Plutonic Gold Mine, Western Australia  

Microsoft Academic Search

Stratigraphy, structure and host-rock chemistry are dominant controls on the location of Au in Archaean greenstone-hosted Au deposits, but the stratigraphy in such deposits is seldom obvious due to the monotonous nature of the host rocks or pervasive alteration associated with Au mineralisation. Portable, hand-held, X-ray fluorescence (pXRF) spectrometry provides a method to rapidly collect large amounts of whole-rock geochemical

Michael F. Gazley; Julie K. Vry; Ettienne du Plessis; Monica R. Handler

2011-01-01

309

Analysis of painted steel by a hand-held X-ray fluorescence spectrometer  

Microsoft Academic Search

Steel with a paint layer was analyzed with a hand-held X-ray fluorescence spectrometer. When the 0.5 mm thick paint layer was composed mainly of light elements, alloying elements in steel such as Fe, Cr, Ni, W, and Mo were easily detected. 0.2% Mo in steel was detectable even if the paint contained Ti or Fe as a main element. The

Hiroyuki Ida; Takao Segawa; Shigeo Tohyama; Jun Kawai

2005-01-01

310

Case Studies on Facility Characterization with X-Ray Fluorescence Spectrometry  

Microsoft Academic Search

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

K. T. Kirk; R. D. Brooksbank; J. M. Meszaros; W. E. Towery

2008-01-01

311

[Simple quantitation of arsenic by energy dispersive fluorescence X-ray spectrometer using Reinsch's test].  

PubMed

We examined the clinical usefulness of the Reinsch's test for the detection of the small amounts of the heavy metals such as arsenic and mercury using the fluorescence X-ray spectrometry. We tried t o measure various kinds of biological samples, including serum, urine, and gastric contents using this method. 0.4 ml or 1 ml of hydrochloric acid were added to 2 ml of serum or 6 ml urine and gastric content, respectively, and a copper plate (5.0x 0.8 cm) was immersed into this solution. The mixture heated at 90 degrees C by a heating block for 30 minutes. After heating, the copper plate was washed with water and dried. The copper arsenide that stuck to the copper plate due to Reinsch's test dissolved by methanol/ammonia (8:2) solution at 60 degrees C for 15 minutes. A drop gave the solution to a filter paper fluorescence X-ray analysis and completely dried the filter paper, and applied to the fluorescence X-ray spectrometer. As a result, this method showed about 20 times high sensitivity in comparison with the measurement with condition of solution. The minimal detectable limits of rsenic was 0.4 ppm in serum and were 0.2 ppm in rine and gastric content. The calibration curve could be made for 0.5 to 50 ppm. It will take about 90 min for the measurement using this method for the detection of arsenic in biological samples. We showed the usefulness of the Reinsch's test using the fluorescence X-ray spectrometry in the clinical toxicology. PMID:15678930

Ozo, Yumiko; Yoshizawa, Mie; Murata, Atsuo; Shimazaki, Syuji; Kajiwara, Masahiro; Takagi, Tetsuya; Sato, Yoshinobu

2004-10-01

312

Twin image removal in X-ray fluorescence holography with two energies  

NASA Astrophysics Data System (ADS)

In the last decade, X-ray fluorescence holography has been developed for the study of 3D atomic arrangements in solids. However, it encounters the twin image problem which may disturb the reconstructed atomic images. In this paper, the formation of twin image is discussed and we propose a modified two-energy algorithm to remove the twin image. The simulation shows that the method is valid and more efficient than the multiple-energy algorithm proposed by Barton.

Chen, Miao-Xin; Li, Zheng

2008-12-01

313

X-ray laser related experiments and theory at Princeton  

SciTech Connect

This paper describes a new system for the development of an x-ray laser in the wavelength region from 5 nm to 1 nm utilizing a Powerful Sub-Picosecond Laser (PP-Laser) of expected peak power up to 0.5 TW in a 300 fs pulse. Soft x-ray spectra generated by the interaction of the PP-Laser beam with different targets are presented and compared to the spectra generated by a much less intense laser beam (20--30 GW). A theoretical model for the interaction of atoms with such a strong laser EM field is also briefly discussed. The development of additional amplifiers for the recombining soft x-ray laser and the design of a cavity are presented from the point of view of applications for x-ray microscopy and microlithography. This overview concludes with the presentation of recent results on the quenching of spontaneous emission radiation and its possible effect on the absolute intensity calibration of soft x-ray spectrometers. 26 refs., 18 figs.

Suckewer, S.

1989-04-01

314

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

PubMed Central

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

Todd, A C; Chettle, D R

1994-01-01

315

Analysis of wrapped or cased object by a hand-held X-ray fluorescence spectrometer.  

PubMed

Metals, alloys, and poisoned food were analyzed with a hand-held X-ray fluorescence (XRF) spectrometer, with a shield (wrapping or casing material) inserted between these objects and the spectrometer, in order to examine the possibility of analyzing the contents of packages. Elements such as Fe, Cr, Ni, Cu, Zn, Pb, Mo, and As were detected in the objects. The fluorescent intensity of each element in the object decreased exponentially as the thickness of the shield increased, and the degree of decrease depended on both the material of the shield and the energy of fluorescent X-rays. The thickness of the shield can be calculated by using the intensity ratio Fe Kbeta/Kalpha or Pb Lbeta/Lalpha when the object is iron or lead, or by using the intensity of the Compton scattering of incident X-rays. The original peak intensity, i.e. intensity without a shield, of an element in an object can be estimated with the thickness of the shield obtained. Because the original peak intensity is calculated using an exponential function of the thickness of the shield, calculation of the intensity ratio, e.g. Zn Kalpha/Cu Kalpha for brass, is effective for cancelling the estimation error for the thickness of the shield. The composition of brass and steel can be estimated with an error of less than 30% by using the intensity of the Compton scattering. PMID:15939161

Ida, Hiroyuki; Kawai, Jun

2005-07-16

316

Monte Carlo methods for the in vivo analysis of cisplatin using X-ray fluorescence.  

PubMed

A Monte Carlo method has been used to model the measurement of cisplatin uptake with in vivo X-ray fluorescence. A user-code has been written for the EGS4 Monte Carlo system that incorporates linear polarisation and multiple element fluorescence extensions. The yield of fluorescent photons to the mainly Compton scattered background is computed for our detector arrangement. The detector consists of a mutually orthogonal arrangement of X-ray tube, aluminium polariser and high purity germanium scintillation detector. The influence of tube voltage on the minimum detectable concentration is modelled for 100 through 150 kVp X-radiation. The code is able to predict absorbed dose to the patient which will influence the optimal choice of tube voltage. The influence of alterations to collimator design and scatterer construction can also be examined. A minimum detectable concentration of 50 ppm is determined from measurements with a 115 kVp X-ray source and a 615 ppm cisplatin sample in a water phantom. PMID:9569576

Hugtenburg, R P; Turner, J R; Mannering, D M; Robinson, B A

317

Development of suitable plastic standards for X-ray fluorescence analysis  

NASA Astrophysics Data System (ADS)

For the adoption of the EU directive “Restriction on use of certain Hazardous Substances” and “Waste Electrical and Electronic Equipment” using X-ray fluorescence analysis suitable standard materials are required. Plastic standards based on acrylonitrile butadiene styrene terpolymer, containing the regulated elements Br, Cd, Cr, Hg and Pb were developed and produced as granulates and solid bodies. The calibration materials were not generated as a dilution from one master batch but rather the element concentrations were distributed over nine independent calibration samples. This was necessary to enable inter-elemental corrections and empirical constant mass absorption coefficients. The produced standard materials are characterized by a homogenous element distribution, which is more than sufficient for X-ray fluorescence analysis. Concentrations for all elements except for Br could be determined by Inductively Coupled Plasma Atomic Emission Spectroscopy after microwave assisted digestion. The concentration of Br was determined by use of Neutron Activation Analysis at Hahn-Meitner-Institute in Berlin, Germany. The correlation of the X-ray fluorescence analysis measurements with the values determined using Inductively Coupled Plasma Atomic Emission Spectroscopy and Neutron Activation Analysis showed a very good linearity.

Mans, Christian; Hanning, Stephanie; Simons, Christoph; Wegner, Anne; Jan?en, Anton; Kreyenschmidt, Martin

2007-02-01

318

A novel x-ray polarimeter based on hexagonal crystal, for application to thermonuclear fusion experiments  

Microsoft Academic Search

A correct estimation of plasma parameters in fusion experiments cannot be done unless the role of polarization of x-ray line emission is recognized.An x-ray polarimeter is presented, based on single hexagonal crystal. The polarimeter selects two polarized components simultaneously. Simple analytical formulae are suggested to determine Bragg angle for analysed x-rays and for the directions of reflected polarized components. The

E. O. Baronova; M. M. Stepanenko

2003-01-01

319

Refractive X-ray lens for high pressure experiments at SPring8  

Microsoft Academic Search

A stacked compound refractive X-ray lens was designed to produce an efficiently focused (?<0.1mm) beam for high-pressure experiments at SPring-8. High-pressure X-ray diffraction requires an intense, high-energy and monochromatic X-ray beam in order to penetrate the absorptive window of a diamond anvil cell (DAC). Our lens, producing a focal spot of 120×275?m2 and a peak gain of 12, is well

Y. Ohishi; A. Q. R. Baron; M. Ishii; T. Ishikawa; O. Shimomura

2001-01-01

320

X-RAY SHADOWING EXPERIMENTS TOWARD INFRARED DARK CLOUDS  

SciTech Connect

We searched for X-ray shadowing toward two infrared dark clouds (IRDCs) using the MOS detectors on XMM-Newton to learn about the Galactic distribution of X-ray emitting plasma. IRDCs make ideal X-ray shadowing targets of 3/4 keV photons due to their high column densities, relatively large angular sizes, and known kinematic distances. Here we focus on two clouds near 30{sup 0} Galactic longitude at distances of 2 and 5 kpc from the Sun. We derive the foreground and background column densities of molecular and atomic gas in the direction of the clouds. We find that the 3/4 keV emission must be distributed throughout the Galactic disk. It is therefore linked to the structure of the cooler material of the interstellar medium and to the birth of stars.

Anderson, L. D.; Bania, T. M. [Department of Astronomy, 725 Commonwealth Ave., Boston University, Boston, MA 02215 (United States); Snowden, S. L. [NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States)

2010-10-01

321

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

PubMed

The first microbeam synchrotron X-ray fluorescence (ľ-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 ľ-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 ľ-SXRF and SXPD have then been installed immediately upstream of the DXL station, with the three techniques sharing available beam time. The ľ-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?ľm 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 ľ-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 ľ-SXRF technique was able to clearly distinguish the distribution of different elements on the specimen. PMID:22713886

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

2012-05-10

322

Interpretation of heterogeneity effects in synchrotron X-ray fluorescence microprobe data  

PubMed Central

Heterogeneity effects often limit the accuracy of synchrotron X-ray fluorescence microprobe elemental analysis data to ą 30%. The difference in matrix mass absorption at K? and K? fluorescence energies of a particular element can be exploited to yield information on the average depth-position of the element or account for heterogeneity effects. Using this technique, the heterogeneous distribution of Cu in a simple layered sample could be resolved to a 2 × 2 × 10 (x, y, z, where z is the depth coordinate) micrometer scale; a depth-resolution limit was determined for the first transition metal series and several other elements in calcite and iron oxide matrices. For complex heterogeneous systems, determination of average element depth may be computationally limited but the influence of heterogeneity on fluorescence data may still be assessed. We used this method to compare solid-state diffusion with sample heterogeneity across the Ni-serpentine/calcite boundary of a rock from Panoche Creek, California. We previously reported that Ni fluorescence data may indicate solid state diffusion; in fact, sample heterogeneity in the depth dimension can also explain the Ni fluorescence data. Depth heterogeneity in samples can lead to misinterpretation of synchrotron X-ray microprobe results unless care is taken to account for the influence of heterogeneity on fluorescence data.

Zavarin, Mavrik; Doner, Harvey E

2002-01-01

323

LabVIEW control software for scanning micro-beam X-ray fluorescence spectrometer.  

PubMed

Confocal micro-beam X-ray fluorescence microscope was constructed. The system was assembled from commercially available components - a low power X-ray tube source, polycapillary X-ray optics and silicon drift detector - controlled by an in-house developed LabVIEW software. A video camera coupled to optical microscope was utilized to display the area excited by X-ray beam. The camera image calibration and scan area definition software were also based entirely on LabVIEW code. Presently, the main area of application of the newly constructed spectrometer is 2-dimensional mapping of element distribution in environmental, biological and geological samples with micrometer spatial resolution. The hardware and the developed software can already handle volumetric 3-D confocal scans. In this work, a front panel graphical user interface as well as communication protocols between hardware components were described. Two applications of the spectrometer, to homogeneity testing of titanium layers and to imaging of various types of grains in air particulate matter collected on membrane filters, were presented. PMID:22483897

Wrobel, Pawel; Czyzycki, Mateusz; Furman, Leszek; Kolasinski, Krzysztof; Lankosz, Marek; Mrenca, Alina; Samek, Lucyna; Wegrzynek, Dariusz

2012-02-11

324

Portable apparatus for in situ x-ray diffraction and fluorescence analyses of artworks.  

PubMed

A portable X-ray fluorescence/X-ray diffraction (XRF/XRD) system for artwork studies has been designed constructed and tested. It is based on Debye Scherrer XRD in reflection that takes advantage of many recent improvements in the handling of X-rays (polycapillary optics; advanced two-dimensional detection). The apparatus is based on a copper anode air cooled X-ray source, and the XRD analysis is performed on a 5-20 ?m thick layer from the object surface. Energy dispersive XRF elemental analysis can be performed at the same point as XRD, giving elemental compositions that support the interpretation of XRD diagrams. XRF and XRD analyses were tested to explore the quality and the limits of the analytical technique. The XRD diagrams are comparable in quality with diagrams obtained with conventional laboratory equipment. The mineral identification of materials in artwork is routinely performed with the portable XRF-XRD system. Examples are given for ceramic glazes containing crystals and for paintings where the determination of pigments is still a challenge for nondestructive analysis. For instance, lead compounds that provide a variety of color pigments can be easily identified as well as a pigment such as lapis lazuli that is difficult to identify by XRF alone. More than 70 works of art have been studied in situ in museums, monuments, etc. In addition to ceramics and paintings, these works include bronzes, manuscripts, etc., which permit improvement in the comprehension of ancient artistic techniques. PMID:21615981

Eveno, Myriam; Moignard, Brice; Castaing, Jacques

2011-05-27

325

A low background x-ray fluorescence system for microsphere quantitation  

SciTech Connect

An automated low background x-ray fluorescence detection system was developed for measuring blood flow rates by the microsphere technique. An x-ray beam was polarized to lower Compton scattering. A Si(Li) detector was used for efficient characteristic x-ray detection with preferentially decreased sensitivity for Compton scattering, a CaF/sub 3/ scintillation detector was engaged in the anti-coincidence method to lower the background, and rise-time rejection was used for the same purpose. One cm/sup 3/ solutions of Rb, Mo, Ag, I, La and Gd with concentration of 0.2-2.0 ppm were measured for 80 minutes and those of 1.0-20 ppm were measured for 10 minutes. For silver, the net counting rate was --75 counts/min/ppm. The anti coincidence detector lowered the background by 10% in the region of silver x-rays. The linear relation between net counts and actual element concentration held up to 1000 ppm for silver solutions.

Morita, Y.; Hosier, K.E.; Lorenz, V.; Kaufman, L.; Mori, H.; Hoffman, J.E.

1988-02-01

326

X-ray optics for scanning fluorescence microscopy and other applications  

SciTech Connect

Scanning x-ray fluorescence microscopy is analogous to scanning electron microscopy. Maps of chemical element distribution are produced by scanning with a very small x-ray beam. Goal is to perform such scanning microscopy with resolution in the range of <1 to 10 {mu}m, using standard laboratory x-ray tubes. We are investigating mirror optics in the Kirkpatrick-Baez (K-B) configuration. K-B optics uses two curved mirrors mounted orthogonally along the optical axis. The first mirror provides vertical focus, the second mirror provides horizontal focus. We have used two types of mirrors: synthetic multilayers and crystals. Multilayer mirrors are used with lower energy radiation such as Cu K{alpha}. At higher energies such as Ag K{alpha}, silicon wafers are used in order to increase the incidence angles and thereby the photon collection efficiency. In order to increase the surface area of multilayers which reflects x-rays at the Bragg angle, we have designed mirrors with the spacing between layers graded along the optic axis in order to compensate for the changing angle of incidence. Likewise, to achieve a large reflecting surface with silicon, the wafers are placed on a specially designed lever arm which is bent into a log spiral by applying force at one end. In this way, the same diffracting angle is maintained over the entire surface of the wafer, providing a large solid angle for photon collection.

Ryon, R.W. [Lawrence Livermore National Lab., CA (United States); Warburton, W.K. [X-Ray Instrumentation Associates, Menlo Park, CA (United States)

1992-05-01

327

NBSGSC - a FORTRAN program for quantitative x-ray fluorescence analysis. Technical note (final)  

SciTech Connect

A FORTRAN program (NBSGSC) was developed for performing quantitative analysis of bulk specimens by x-ray fluorescence spectrometry. This program corrects for x-ray absorption/enhancement phenomena using the comprehensive alpha coefficient algorithm proposed by Lachance (COLA). NBSGSC is a revision of the program ALPHA and CARECAL originally developed by R.M. Rousseau of the Geological Survey of Canada. Part one of the program (CALCO) performs the calculation of theoretical alpha coefficients, and part two (CALCOMP) computes the composition of the analyte specimens. The analysis of alloys, pressed minerals, and fused specimens can currently be treated by the program. In addition to using measured x-ray tube spectral distributions, spectra from seven commonly used x-ray tube targets could also be calculated with an NBS algorithm included in the program. NBSGSC is written in FORTRAN IV for a Digital Equipment Corporation (DEC PDP-11/23) minicomputer using RLO2 firm disks and an RSX 11M operating system.

Tao, G.Y.; Pella, P.A.; Rousseau, R.M.

1985-04-01

328

Cancer diagnosis using a conventional x-ray fluorescence camera with a cadmium-telluride detector  

NASA Astrophysics Data System (ADS)

X-ray fluorescence (XRF) analysis is useful for mapping various atoms in objects. Bremsstrahlung X-rays are selected using a 3.0 mm-thick aluminum filter, and these rays are absorbed by indium, cerium and gadolinium atoms in objects. Then XRF is produced from the objects, and photons are detected by a cadmium-telluride detector. The K? photons are discriminated using a multichannel analyzer, and the number of photons is counted by a counter card. The objects are moved and scanned by an x-y stage in conjunction with a two-stage controller, and X-ray images obtained by atomic mapping are shown on a personal computer monitor. The scan steps of the x and y axes were both 2.5 mm, and the photon-counting time per mapping point was 0.5 s. We carried out atomic mapping using the X-ray camera, and K? photons from cerium and gadolinium atoms were produced from cancerous regions in nude mice.

Sato, Eiichi; Enomoto, Toshiyuki; Hagiwara, Osahiko; Abudurexiti, Abulajiang; Sato, Koetsu; Sato, Shigehiro; Ogawa, Akira; Onagawa, Jun

2011-09-01

329

Effect of powder sample granularity on fluorescent intensity and on thermal parameters in x-ray diffraction Rietveld analysis.  

National Technical Information Service (NTIS)

The effect of sample granularity on diffracted x-ray intensity was evaluated by measuring the 2(theta) dependence of x-ray fluorescence from various samples. Measurements were made in the symmetric geometry on samples ranging from single crystals to highl...

C. J. Sparks E. D. Specht G. E. Ice R. Kumar P. Zschack

1991-01-01

330

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

PubMed

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

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

2011-09-09

331

Fluorescent computer tomography; A model for correction of x-ray absorption  

SciTech Connect

The distributions of individual trace elements within a sample can be found using fluorescent computed tomography (FCT). The absorption of incident and fluorescent X-rays results in degraded reconstructions of the distributions. The proposed method uses the absorption density, measured using conventional absorption tomography, to remove absorption effects. A model for FCT with absorption is developed and simulated. The resulting corrected reconstructions are compared to the reconstructions degraded by attenuation effects. In this paper a comparison is made with other methods which utilize knowledge of the sample composition and a standard source to estimate the absorption coefficients used to correct for attenuation effects.

Hogan, J.P.; Gonsalves, R.A. (Electro-Optics Technology Center, Tufts Univ., Medford, MA (US)); Krieger, A.S. (Radiation Science, Inc., Belmont, MA (US))

1991-12-01

332

Enhanced coherence x-ray laser experiments and simulations  

Microsoft Academic Search

Bright, spatially coherent x-ray lasers (XRLs) have applications in areas such as holography, interferometric imaging, and non-linear optics. Nominally, we can improve XRL coherence by either increasing the length or by reducing the aperture. The length can be increased by coupling multiple stages of XRLs or by using multilayer optics, but the effective gain length of an XRL is limited

Alan S. Wan; Stephen B. Libby; Juan C. Moreno

1994-01-01

333

The X-ray Detector Test experiment on Mir  

Microsoft Academic Search

In 1996 and 1997 PSI developed the X-ray Detector Test (XDT) Instrument, sponsored by NASA through UAB\\/CMC. The Instrument contains three sensor subsystems, each using a high sensitivity photomultiplier tube (PMT) as the radiation event detector. One subsystem has the PMT alone; the second has the PMT coupled to a fiberoptic cylinder; and the third has the PMT coupled to

Iraja N. Bandeira; Huberto Closs; Nelson Veissid; Stephen R. Smith; William T. McDonald; Lawrence J. Delucas

2000-01-01

334

Apollo 16 Experiments - Fluorescence Spectrometer  

NSDL National Science Digital Library

This page, from the Lunar and Planetary Institute, describes how the composition of portions of the lunar surface was determined by observing the fluorescence produced by solar x-rays. Images are provided with results from the experiments and links are offered to other LPI pages with information on the Apollo missions. This page is written at the level of introductory physics.

2009-07-29

335

X-ray Absorption Fine Structure Combined with X-ray Fluorescence Spectrometry. Part 15. Monitoring of Vanadium Site Transformations on Titania and in Mesoporous Titania by Selective Detection of the Vanadium K? 1 Fluorescence  

Microsoft Academic Search

X-ray absorption fine structure combined with X-ray fluorescence spectrometry was applied to various V+TiO2 hybrid samples. Emitted V KR1 fluorescence from the sample was selectively counted by using a high- energy-resolution (0.4 eV) spectrometer equipped with a Ge(331) crystal. Two advantages of this method, extremely high signal\\/background ratio and the compatibility of measurements in the atmosphere of reaction gas (in

Yasuo Izumi; Fumitaka Kiyotaki; Nobuhiro Yagi; Aurel-Mihai Vlaicu; Atsushi Nisawa; Sei Fukushima; Hideaki Yoshitake; Yasuhiro Iwasawa

2005-01-01

336

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  

Microsoft Academic Search

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

G. Pepponi; P. Wobrauschek; F. Hegedüs; C. Streli; N. Zöger; C. Jokubonis; G. Falkenberg; H. Grimmer

2001-01-01

337

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

SciTech Connect

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

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

2010-01-01

338

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

SciTech Connect

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.

Grodzins, Lee; Niland, John

2002-05-23

339

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

SciTech Connect

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.

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

340

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

NASA Astrophysics Data System (ADS)

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.

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

341

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

PubMed

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

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

2009-10-24

342

Reverse engineering the ancient ceramic technology based on X-ray fluorescence spectromicroscopy  

SciTech Connect

We present results of X-ray fluorescence (XRF) microprobe analyses of ancient ceramic cross-sections aiming at deciphering the different firing protocols used for their production. Micro-focused XRF elemental mapping, Fe chemical mapping and Fe K-edge X-ray absorption near edge structure spectroscopy were performed on pre-sigillata ceramics from southern Gaul, and terra Sigillata vessels from Italy and southern Gaul. Pieces from the different workshops and regions showed significant difference in the starting clay material, clay conditioning and kiln firing condition. By contrast, sherds from the same workshop exhibited more subtle differences and possible misfirings. Understanding the precise firing conditions and protocols would allow recreation of kilns for various productions. Furthermore, evolution and modification of kiln design would shed some light on how ancient potters devised solutions to diverse technological problems they encountered.

Sciau, Philippe; Leon, Yoanna; Goudeau, Philippe; Fakra, Sirine C.; Webb, Sam; Mehta, Apurva

2011-07-06

343

Elemental investigation on Spanish dinosaur bones by x-ray fluorescence  

NASA Astrophysics Data System (ADS)

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.

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

2013-07-01

344

Use of x-ray fluorescence and diffraction techniques in studying ancient ceramics of Sri Lanka  

NASA Astrophysics Data System (ADS)

Ceramics were produced for centuries in Sri Lanka for various purposes. Ancient ceramic articles such as pottery, bricks, tiles, sewer pipes, etc, were made from naturally occurring raw materials. Use of X-ray fluorescence (XRF), X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) in characterizing of two ancient ceramic samples from two different archaeological sites in Sri Lanka is presented. The information obtained in this manner is used to figure out the ancient ceramic technology, particularly to learn about the raw materials used, the source of raw materials, processing parameters such as firing temperature or binders used in ceramic production. This information then can be used to explore the archaeometric background such as the nature and extent of cultural and technological interaction between different periods of history in Sri Lanka.

Karunaratne, B. S. B.

2012-07-01

345

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...

346

Magnetic circular dichroism in the L 2,3 x-ray fluorescence of Fe and Co  

Microsoft Academic Search

the L2,3 x-ray fluorescence spectra of magnetized Fe and CO excited by circularly polarized synchrotron radiation exhibit magnetic circular dichroism. The results are compared to the energy resolved spin polarized densities of states given by first-principles calculations. High resolution x-ray fluorescence (XRF) spectroscopy consists in measuring inelastically scattered photons. The energy, direction and polarization of the primary radiation may be

J.-M. Mariot; C. F. Hague

1994-01-01

347

An x-ray fluorescence imaging system for gold nanoparticle detection.  

PubMed

Gold nanoparticles (GNPs) may be used as a contrast agent to identify tumour location and can be modified to target and image specific tumour biological parameters. There are currently no imaging systems in the literature that have sufficient sensitivity to GNP concentration and distribution measurement at sufficient tissue depth for use in in vivo and in vitro studies. We have demonstrated that high detecting sensitivity of GNPs can be achieved using x-ray fluorescence; furthermore this technique enables greater depth imaging in comparison to optical modalities. Two x-ray fluorescence systems were developed and used to image a range of GNP imaging phantoms. The first system consisted of a 10 mm(2) silicon drift detector coupled to a slightly focusing polycapillary optic which allowed 2D energy resolved imaging in step and scan mode. The system has sensitivity to GNP concentrations as low as 1 ppm. GNP concentrations different by a factor of 5 could be resolved, offering potential to distinguish tumour from non-tumour. The second system was designed to avoid slow step and scan image acquisition; the feasibility of excitation of the whole specimen with a wide beam and detection of the fluorescent x-rays with a pixellated controlled drift energy resolving detector without scanning was investigated. A parallel polycapillary optic coupled to the detector was successfully used to ascertain the position where fluorescence was emitted. The tissue penetration of the technique was demonstrated to be sufficient for near-surface small-animal studies, and for imaging 3D in vitro cellular constructs. Previous work demonstrates strong potential for both imaging systems to form quantitative images of GNP concentration. PMID:24145214

Ricketts, K; Guazzoni, C; Castoldi, A; Gibson, A P; Royle, G J

2013-10-21

348

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

SciTech Connect

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.

Worley, Christopher G [Los Alamos National Laboratory

2009-01-01

349

Ultrafast X-ray Experiments Using Terahertz Excitation  

Microsoft Academic Search

With the availability of the first generation of X-ray free electron lasers, pump-probe measurements with femtosecond resolution and high brilliance are now possible. For condensed matter systems, a wealth of modes in the mid-infrared (MIR) and terahertz (THz) regime determine the physics such that targeted excitation with ultrashort pulses at long wavelength becomes an important tool. We will briefly discuss

Matthias C. Hoffmann; Joshua J. Turner

2012-01-01

350

Preliminary investigation of trace element in Pterygium using Synchrotron radiation micro-beam X-ray fluorescence analysis (-XRF)  

NASA Astrophysics Data System (ADS)

We have assessed the relative content and distribution of Iron and Zinc elements using microbeam synchrotron radiation X-ray fluorescence technique. One such technique is X-ray fluorescence (XRF), which has been used previously to map trace elements distribution in Physical samples. In this article a compromise is suggested in issue Pterygium samples. In this study, a prospective randomized clinical trial was conducted. Serial frozen sections of pterygium tissues and conjunctival tissues of 40 ?m thickness were collected from 8 patients Ł¨10 eyesŁŠundergoing pterygium excision combine with limbal stem cell transplantation. A synchrotron-based XRF microprobe was used to map the distribution of Fe and Zn in whole frozen pterygium sections. The frozen sections were tested by synchrotron radiation X-ray fluorescence technique. These experiments were performed at BL15U in Shanghai, China. Then, the results have palyed that Iron and Zinc were present in both pterygium tissues and normal conjunctiva tissues (relevance ratio 100%). The contents of Iron and Zinc in normal conjunctiva tissues were significantly lower than in pterygium tissues (P < 0.05). The microelements were mostly clusteredin the pterygium tissues, while sparsely distributed in the normal conjunctiva tissue. Finally, we found that XRF imaging will be useful for mapping elemental distribution in Pterygium tissues. 40 ?m frozen section on 6 ?m mylar film is good for the test on BL15U. The contents of Iron and Zinc in pterygium tissue were significantly higher than in the control tissues. The results seem to be valuable in that Iron and Zinc may play a role in the development process of Pterygium.

Xie, Q.; Peng, L.; Cai, F.; Li, Ai G.; Yang, K.

2013-07-01

351

Same-Shot X-Ray Thomson Scattering and Streaked Imaging of Xenon Radiative Shock Experiments  

NASA Astrophysics Data System (ADS)

We review the experimental design and results from recent CRASH radiative shock experiments at the Omega Laser facility. These experiments seek to measure the system with high accuracy, employing streaked x-ray radiography and x-ray Thomson scattering diagnostics on each shot. We detail how this diagnostic combination allows for precise interrogation of the different regions of the shock, including the radiation-heated upstream precursor, the radiatively collapsed cooling layer, and the downstream material. Spatially and temporally correlated data from the x-ray streak camera and gated spectrometer is shown, and plans for future iterations of radiative shock experiments are also discussed.

Huntington, Channing; Gamboa, Eliseo; Krauland, Christine; Kuranz, Carolyn; Drake, R. Paul; Glenzer, Siegfried

2011-11-01

352

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

NASA Astrophysics Data System (ADS)

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.

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

353

Automation of dihydroxyaluminum sodium carbonate analysis in antacid tablets by energy dispersive X-ray fluorescence.  

PubMed

A sensitive, specific, automated energy dispersive X-ray fluorescence (EDXRF) method for determination of anhydrous dihydroxyaluminum sodium carbonate in antacid tablets has been developed. The compound was quantitated by impact grinding, pelletizing at 10 tons pressure, and monitoring the aluminum by using a rhodium anode X-ray tube, high resolution thermoelectrically cooled Si(Li) detector with sample spinning, and computer data processing. The assay procedure was validated with spiked laboratory-prepared samples at 100 +/- 20% levels. The average recovery was 100.6% with a relative standard deviation of 1.6% (n = 14). Instrument precision was determined and found to have an average relative standard deviation of 1.0% (n = 16). In addition, analysis precision by the EDXRF method was compared to that for titration and autoanalyzer methodologies and found to be statistically comparable. The sample precision had an averaged relative standard deviation of 2.7% (n = 16) by X-ray methodology. The advantages of this EDXRF method include increased sample throughout with excellent precision and accuracy, no solvent usage, and automated data handling. PMID:2376540

Georgiades, C A

354

Phase-resolved x-ray ferromagnetic resonance measurements in fluorescence yield  

SciTech Connect

Phase-resolved x-ray ferromagnetic resonance (XFMR) has been measured in fluorescence yield, extending the application of XFMR to opaque samples on opaque substrates. Magnetization dynamics were excited in a Co{sub 50}Fe{sub 50}(0.7)/Ni{sub 90}Fe{sub 10}(5) bilayer by means of a continuous wave microwave excitation, while x-ray magnetic circular dichroism (XMCD) spectra were measured stroboscopically at different points in the precession cycle. By tuning the x-ray energy to the L{sub 3} edges of Ni and Fe, the dependence of the real and imaginary components of the element specific magnetic susceptibility on the strength of an externally applied static bias field was determined. First results from measurements on a Co{sub 50}Fe{sub 50}(0.7)/Ni{sub 90}Fe{sub 10}(5)/Dy(1) sample confirm that enhanced damping results from the addition of the Dy cap.

Marcham, M. K.; Keatley, P. S.; Neudert, A.; Hicken, R. J.; Cavill, S. A.; Shelford, L. R.; van der Laan, G.; Telling, N. D.; Childress, J. R.; Katine, J. A.; Shafer, P.; Arenholz, E.

2010-10-14

355

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

PubMed Central

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.

Ducic, Tanja; Barski, Elisabeth; Salome, Murielle; Koch, Jan C; Bahr, Mathias; Lingor, Paul

2013-01-01

356

Wavelength dispersive X-ray fluorescence imaging using a high-sensitivity imaging sensor  

NASA Astrophysics Data System (ADS)

A new wavelength-dispersive X-ray fluorescence (WD-XRF) imaging spectrometer equipped with a high-sensitivity imaging sensor was developed in our laboratory. In this instrument, a straight polycapillary optic was applied instead of a Soller slit as well as a 2D imaging X-ray detector instead of X-ray counters, which are used in conventional WD-XRF spectrometers. Therefore, images of elemental distribution were available after a short exposure time. Ni K? images and Cu K? images were clearly obtained at corresponding diffraction angles for a short exposure time of 10 s. By optimizing the spectrometer, the time required for imaging is reduced, leading to XRF image movies. It is difficult to distinguish two peaks (Ti K? (4.508 keV) and Ba L? (4.465 keV)) due to the poor energy resolution of EDXRS. However, Ti and Ba images could be successfully observed by the WD-XRF imaging spectrometer. The energy resolution of the developed spectrometer was 25 eV at the Ti K? peak.

Ohmori, Takashi; Kato, Shuichi; Doi, Makoto; Shoji, Takashi; Tsuji, Kouichi

2013-05-01

357

InFOCuS Balloon-borne Hard X-Ray Experiment with Multilayer Supermirror X-ray Telescope  

Microsoft Academic Search

We have been developing the high throughput hard X-ray telescope, using reflectors coated with the depth graded multilayer known as supermirror. InFOCuS, the International Focusing Optics Collaboration for micro-Crab Sensitivity is the project of the balloon observation of cosmic hard X-ray source with this type of hard X-ray telescope and CdZnTe pixel detector as a focal plane imager. The first

Y. Tawara; K. Yamashita; Y. Ogasaka; K. Tamura; K. Haga; T. Okajima; S. Ichimaru; S. Takahasi; A. Gotou; H. Kitou; S. Fukuda; H. Kuneida; Y. Tsusaka; J. Tueller; P. J. Serlemitsos; Y. Soong; K. W. Chan; S. M. Owens; F. Berendse; B. Barber; E. Dereniak; E. Young

2000-01-01

358

InFOCuS balloon-borne hard x-ray experiment with multilayer supermirror x-ray telescope  

Microsoft Academic Search

We have been developing the high throughput hard X-ray telescope, using reflectors coated with the depth graded multilayer known as supermirror, which is considered to be a key technology for future satellite hard X-ray imaging missions. InFOC(mu) $S, the International Focusing Optics Collaboration for (mu) -Crab Sensitivity is the project of the balloon observation of a cosmic hard X-ray source

Yuzuru Tawara; Kojun Yamashita; Yasushi Ogasaka; Keisuke Tamura; Kazutoshi Haga; Takashi Okajima; Satoshi Ichimaru; Seiji Takahashi; Arifumi Gotou; Hideo Kitou; Shinichi Fukuda; Yuichi Kamata; Akihiro Furuzawa; Fumie Akimoto; Tsutomu Yoshioka; Kazuo Kondou; Yoshito Haba; Takeshi Tanaka; Hideyo Kunieda; Kazutami Misaki; Jack Tuller; Peter J. Serlemitsos; Kai-Wing Chan; Yang Soong; Scott M. Owens; Fred Berendse; W. H. Baugartner; Hans Krimm; H. Bradford Barber; Erick T. Young

2002-01-01

359

Application of imaging plate to x-ray imaging and spectroscopy in laser plasma experiments  

SciTech Connect

We report recent progress of x-ray diagnostic techniques in laser plasma experiment with using imaging plates. Imaging plate is a photo-stimulable phosphor screen (BaF(Br0.85,10.15):Eu{sup 2+}) deposited on flexible metal or plastic substrate. We applied the imaging plate to x-ray microscopy in laser fusion experiment experiments. Self-emission x-ray images of imploded core were obtained successfully with using imaging plate and high magnification target mounted pinhole arrays. The imaging plates were applied also in ultra-intense laser experiment at the Rutherford Appleton Laboratory. Small samarium foil was irradiated by high intensity laser pulse from the Vulcan laser system. The k shell x-rays from the foil ({approx}40keV) was used as a line x-ray source for microscopic radiography. Performance of imaging plate on high-energy x-ray backlit radiography was demonstrated by imaging sinusoidal grooves of 6um amplitude on a Au foil. Detailed spectrum of k shell x-ray from Cu embedded foil target was successfully observed by fully coupling imaging plate with a highly ordered pyrolytic graphite crystal spectrometer. The performances of the imaging plates evaluated in actual laser plasma experiments will be presented.

Izumi, N; Snavely, R; Gregori, G; Koch, J A; Park, H; Remington, B A

2006-04-25

360

New Homogeneous Standards by Atomic Layer Deposition for Synchrotron X-ray Fluorescence and Absorption Spectroscopies.  

SciTech Connect

Quantification of synchrotron XRF analyses is typically done through comparisons with measurements on the NIST SRM 1832/1833 thin film standards. Unfortunately, these standards are inhomogeneous on small scales at the tens of percent level. We are synthesizing new homogeneous multilayer standards using the Atomic Layer Deposition technique and characterizing them using multiple analytical methods, including ellipsometry, Rutherford Back Scattering at Evans Analytical, Synchrotron X-ray Fluorescence (SXRF) at Advanced Photon Source (APS) Beamline 13-ID, Synchrotron X-ray Absorption Spectroscopy (XAS) at Advanced Light Source (ALS) Beamlines 11.0.2 and 5.3.2.1 and by electron microscopy techniques. Our motivation for developing much-needed cross-calibration of synchrotron techniques is borne from coordinated analyses of particles captured in the aerogel of the NASA Stardust Interstellar Dust Collector (SIDC). The Stardust Interstellar Dust Preliminary Examination (ISPE) team have characterized three sub-nanogram, {approx}1{micro}m-sized fragments considered as candidates to be the first contemporary interstellar dust ever collected, based on their chemistries and trajectories. The candidates were analyzed in small wedges of aerogel in which they were extracted from the larger collector, using high sensitivity, high spatial resolution >3 keV synchrotron x-ray fluorescence spectroscopy (SXRF) and <2 keV synchrotron x-ray transmission microscopy (STXM) during Stardust ISPE. The ISPE synchrotron techniques have complementary capabilities. Hard X-ray SXRF is sensitive to sub-fg mass of elements Z {ge} 20 (calcium) and has a spatial resolution as low as 90nm. X-ray Diffraction data were collected simultaneously with SXRF data. Soft X-ray STXM at ALS beamline 11.0.2 can detect fg-mass of most elements, including cosmochemically important oxygen, magnesium, aluminum and silicon, which are invisible to SXRF in this application. ALS beamline 11.0.2 has spatial resolution better than 25 nm. Limiting factors for Stardust STXM analyses were self-imposed limits of photon dose due to radiation damage concerns, and significant attenuation of <1500 eV X-rays by {approx}80{micro}m thick, {approx}25 mg/cm{sup 3} density silica aerogel capture medium. In practice, the ISPE team characterized the major, light elements using STXM (O, Mg, Al, Si) and the heavier minor and trace elements using SXRF. The two data sets overlapped only with minor Fe and Ni ({approx}1% mass abundance), providing few quantitative cross-checks. New improved standards for cross calibration are essential for consortium-based analyses of Stardust interstellar and cometary particles, IDPs. Indeed, they have far reaching application across the whole synchrotron-based analytical community. We have synthesized three ALD multilayers simultaneously on silicon nitride membranes and silicon and characterized them using RBS (on Si), XRF (on Si{sub 3}N{sub 4}) and STXM/XAS (holey Si{sub 3}N{sub 4}). The systems we have started to work with are Al-Zn-Fe and Y-Mg-Er. We have found these ALD multi-layers to be uniform at {micro}m- to nm scales, and have found excellent consistency between four analytical techniques so far. The ALD films can also be used as a standard for e-beam instruments, eg., TEM EELS or EDX. After some early issues with the consistency of coatings to the back-side of the membrane windows, we are confident to be able to show multi-analytical agreement to within 10%. As the precision improves, we can use the new standards to verify or improve the tabulated cross-sections.

Butterworth, A.L.; Becker, N.; Gainsforth, Z.; Lanzirotti, A.; Newville, M.; Proslier, T.; Stodolna, J.; Sutton, S.; Tyliszczak, T.; Westphal, A.J.; Zasadzinski, J. (UCB)

2012-03-13

361

In-vivo Fluorescent X-ray CT Imaging of Mouse Brain  

SciTech Connect

Using a non-radioactive iodine-127 labeled cerebral perfusion agent (I-127 IMP), fluorescent X-ray computed tomography (FXCT) clearly revealed the cross-sectional distribution of I-127 IMP in normal mouse brain in-vivo. Cerebral perfusion of cortex and basal ganglion was depicted with 1 mm in-plane spatial resolution and 0.1 mm slice thickness. Degree of cerebral perfusion in basal ganglion was about 2-fold higher than that in cortical regions. This result suggests that in-vivo cerebral perfusion imaging is realized quantitatively by FXCT at high volumetric resolution.

Takeda, T.; Wu, J.; Lwin, Thet-Thet; Huo, Q.; Minami, M. [Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8575 (Japan); Sunaguchi, N.; Murakami, T.; Mouri, S.; Nasukawa, S.; Yuasa, T.; Akatsuka, T. [Faculty of Engineering, Yamagata University, Yonezawa, Yamagata 992-8510 (Japan); Hyodo, K. [Institute of Material Science, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801 (Japan); Hontani, H. [Department of Computer Science and Engineering, Nagoya Institute of Technology, Nagoya, Aichi 466-8555 (Japan)

2007-01-19

362

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

NASA Astrophysics Data System (ADS)

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.

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

1997-07-01

363

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

SciTech Connect

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.

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

364

X-ray fluorescence analysis of archaeological finds and art objects: recognizing gold and gilding.  

PubMed

Many cultural heritage objects were gilded in the past, and nowadays they can be found in archeological excavations or in historical buildings dating back to the Middle Ages, or from the modern period. Old gilded artifacts have been studied using X-ray fluorescence analysis and 2D microanalysis. Several techniques that enable the user to distinguish gold and gilded objects are described and then applied to investigate artifacts. These techniques differ in instrumentation, data analysis and numbers of measurements. The application of Monte Carlo calculation to a quantitative analysis of gilded objects is also introduced. PMID:22484145

Trojek, Tomáš; Hložek, Martin

2012-03-29

365

Performance of a Borehole X-Ray Fluorescence Spectrometer for Planetary Exploration  

Microsoft Academic Search

We have designed and constructed a borehole X-ray fluorescence spectrometer (XRFS) as part of the Mars Subsurface Access program (http:\\/\\/marstech.jpl.nasa.gov\\/content\\/detail.cfm?Sect=MTP&Cat=base&subCat=SSA&subSubCat=&TaskID=2256). 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

W. C. Kelliher; I. A. Carlberg; W. T. Elam; E. Willard-Schmoe

2008-01-01

366

Waste reduction and process improvements in the analysis of plutonium by x-ray fluorescence  

SciTech Connect

Significant modifications were made to a sample preparation process for quantifying gallium in plutonium metal by wavelength dispersive X-ray fluorescence. These changes were made to minimize waste and improve process safety and efficiency. Sample sizes were reduced, cheaper sample preparation acids were used, and safety improvements were implemented. Using this modified process, results from analyzing a batch oftest samples indicated that relative precision and accuracy were {approx}0.2% and {approx}0.1% respectively, which is comparable to that obtained using the older, established sample preparation method.

Worley, Christopher G [Los Alamos National Laboratory; Sodweberg, Constance B [Los Alamos National Laboratory; Townsend, Lisa E [Los Alamos National Laboratory

2009-01-01

367

Lead nephropathy: In vivo x ray fluorescence (XRF) for assessing body lead stores  

SciTech Connect

The EDTA lead mobilization test has proven of value in the diagnosis of renal disease due to lead (lead nephropathy) but is unsuitable for large scale studies in patients with end-stage renal disease. A rapid, safe, non-invasive technique for determining body lead stores by in vivo tibial x ray fluorescence (XRF) is described. These studies show that the chelation test can be replaced by in vivo XRF in patients with end-stage renal disease. XRF, for the first time, will permit epidemiologic studies of large populations which may be at risk for lead nephropathy from excessive exposure to environmental lead. 15 refs., 2 figs.

Wedeen, R.P.; Batuman, V.; Quinless, F.; Williams, F.H. Jr.; Bogden, J.; Schidlovsky, G.; Jones, K.W.

1986-01-01

368

Portable X-ray fluorescence instruments for the analysis of lead in paints.  

PubMed Central

In a study in the laboratories of the Chicago Board of Health, the results from determination of lead in paint films by X-ray fluorescence were compared with results from determination by atomic absorption. Portable instruments of three suppliers were used for X-ray fluorescence measurements. An improved version of one of these instruments was also tested. The results of X-ray fluorescence readings on painted card stock panels with one of these instruments compared satisfactorily with the results as determined by the atomic absorption method at levels below 10 mg of lead per square centimeter. Readings on multiple layers of these panels were additive and independent of the order of these panels. All four instruments were tested in the laboratory on painted surfaces from the walls of condemned buildings. The most recent version of each instrument gave a correlation coefficient of 0.96 or better for the linear regression of lead values in milligrams per square centimeter by atomic absorption against instrument readings. It was calculated that a reading of 3.2 or greater on any of the instruments would indicate with greater than 95 percent confidence that 1 mg or more of lead per square centimeter would be found when a sample of the paint was analyzed by atomic absorption. When the readings of one of the instruments showed lead to be absent, that result would inidcate with better than 95 percent confidence that less than 1 mg of lead per square centimeter would be found by the atomic absorption method. Portable X-ray fluorescence instruments can be used in situ to determine whether the walls of a building give readings for lead above the range of 0 to 3.2. Walls with readings above this range can be considered to have 1 mg or more of lead per square centimeter and would not be in conformance with the code of the City of Chicago. Samples would need to be taken for analysis in the laboratory by atomic absorption only from those walls with readings within the range of 0 to 3.2. Images p224-a 1. 2. 3.

Kaplan, E H; Lilley, M D; Schaefer, R F; Cade, B; Desai, A; Padva, A; Orbach, H G

1975-01-01

369

X-ray fluorescence imaging system for fast mapping of pigment distributions in cultural heritage paintings  

NASA Astrophysics Data System (ADS)

Conventional X-ray fluorescence imaging technique uses a focused X-ray beam to scan through the sample and an X-ray detector with high energy resolution but no spatial resolution. The spatial resolution of the image is then determined by the size of the exciting beam, which can be obtained either from a synchrotron source or from an X-ray tube with a micro-capillary lens. Such a technique based on a pixel-by-pixel measurement is very slow and not suitable for imaging large area samples. The goal of this work is to develop a system capable of simultaneous imaging of large area samples by using a wide field uniform excitation X-ray beam and a position sensitive and energy dispersive detector. The development is driven by possible application of such a system to imaging of distributions of hidden pigments containing specific elements in cultural heritage paintings, which is of great interest for the cultural heritage research. The fluorescence radiation from the area of 10 × 10 cm2 is projected through a pinhole camera on the Gas Electron Multiplier detector of the same area. The detector is equipped with two sets of orthogonal readout strips. The strips are read out by the GEMROC Application Specific Integrated Circuits (ASIC)s, which deliver time and amplitude information for each hit. This ASIC architecture combined with a Field Programmable Gate Array (FPGA) based readout system allows us to reconstruct the position and the total energy of each detected photon for high count rates up to 5 × 106 cps. Energy resolution better than 20% FWHM for the 5.9 keV line and spatial resolution of 1 mm FWHM have been achieved for the prototype system. Although the energy resolution of the Gas Electron Multiplier (GEM) detector is, by principle, not competitive with that of specialised high energy resolution semiconductor detectors, it is sufficient for a number of applications. Compared to conventional micro-XRF techniques the developed system allows shortening of the measurement time by 2-3 orders of magnitude.

Zieli?ska, A.; D?browski, W.; Fiutowski, T.; Mindur, B.; Wi?cek, P.; Wróbel, P.

2013-10-01

370

Fluorescence X-ray microscopy on hydrated tributyltin-clay mineral suspensions  

NASA Astrophysics Data System (ADS)

Using the scanning transmission X-ray microscope at ID21 beamline of the ESRF in fluorescence mode, we mapped tin at a bulk concentration of 1000 ?g(Sn)/ml within hydrated tributyltin (TBT)-clay mineral (Kaolinite) dispersion with sub-300 nm spatial resolution. Using the L absorption edges of tin at 3929, 4156 and 4465 eV fluorescence radiation was excited in tin atoms with incident photon energies of 4 and 4.5 keV. When using 4 keV radiation, only tin fluorescence is excited. For 4.5 keV X rays, both the fluorescence of tin and calcium (which is present in the solid phase) can be measured. Methodologically, we were interested in assessing and proving the possibilities and limitations of fluorescence mapping using the L absorption edges of tin, where the fluorescence yield is significantly lower compared to other elements with their K edges in the same energy range. Scientifically, organotin-clay mineral interactions are of environmental concern because this factor influences significantly the distribution of toxic TBT in the aquatic System. On one hand, the half-life of TBT deposited to the sediment phase increases, and consequently the time of its bioavailability. On the other hand, the adsorption process is reversible, which means that contaminated sediments can act as a source of pollution. The adsorption and desorption effects can be studied directly with high spatial resolution and brought into connection to the surface properties of the clay mineral under study as well as to other experimental parameters, like pH or salinity.

Neuhäusler, U.; Schmidt, C.; Hoch, M.; Susini, J.

2003-03-01

371

Total X-Ray Power Improvement on Recent Wire Array Experiments on the Z Machine  

Microsoft Academic Search

Recent experiments on the refurbished Z-machine were conducted using large diameter stainless steel arrays which produced x-ray powers of 260 TW. ootnotetextD.J. Ampleford, International Conference on Plasma Science, 2009 Follow-up experiments were then conducted utilizing tungsten wires with approximately the same total mass with the hypothesis that the total x-ray power would increase. On the large diameter tungsten experiments, the

Michael Jones; David J. Ampleford; Mike Cuneo; Chris Jennings; Brent Jones; Mike Lopez; Greg Rochau; Mark Savage; John Porter

2010-01-01

372

Treatment of Acid Mine Drainage. Column experiments and X-ray microtomography.  

NASA Astrophysics Data System (ADS)

Column experiments to emulate the behavior of passive treatment systems for acid mine drainage (AMD) were carried out. Synthetic acidic solutions made up of H2SO4 and Fe (III) (200-1500 ppm) at pH 2 circulated through columns filled with grains of calcite, aragonite or dolomite at a constant flow rate (6e-7 or 1e-6 m3/m2//s). Grain size ranged between 1 and 2 mm. The columns worked as an efficient barrier for some time, increasing the pH of the circulating solution to about 7 and removing its metal content. Results show that acidic solution reacts with the carbonate surfaces and newly precipitated gypsum coats the carbonate grains, eventually causing the passivation of the system. Metal-oxyhydroxysulfates precipitate mostly at the central regions of pore space. Variation in porosity and secondary mineral precipitation (gypsum, goethite, schwertmannite in some cases) was investigated with X-ray microtomography. Reaction fronts advance along the columns (precipitation of gypsum and Fe-oxyhydroxysulfates). Variation in porosity due to secondary mineral precipitation is quantified and formation of preferential flow paths in the porous medium is observed. In addition, X-ray fluorescence was performed to map the metal content and metal distribution.

Offeddu, Francesco; Tiseanu, Ion; Cama, Jordi; Soler, Josep M.; Ayora, Carlos

2010-05-01

373

Characterization of the Carancas-Puno meteorite by energy dispersive X-ray fluorescence, X-ray diffractometry and transmission Mössbauer spectroscopy  

NASA Astrophysics Data System (ADS)

We report the results of the study of a meteorite that impacted an inhabited zone on 15 September 2007 in the neighborhood of the town of Carancas, Puno Region, about 1,300 km south of Lima. The analysis carried out by energy dispersive X-ray fluorescence, X-ray diffractometry and transmission Mössbauer spectroscopy (at room temperature and at 4.2 K), reveal the presence in the meteorite sample of magnetic sites assigned to taenite (Fe,Ni) and troilite (Fe,S) phases, and of two paramagnetic doublets assigned to Fe2 + , one associated with olivine and the other to pyroxene. In accord with these results, this meteorite is classified as a type IV chondrite meteorite.

Cerón Loayza, María L.; Bravo Cabrejos, Jorge A.

2011-08-01

374

Cloning, expression, purification and crystallization as well as X-ray fluorescence and preliminary X-ray diffraction analyses of human ADP-ribosylhydrolase 1.  

PubMed

Human ADP-ribosylhydrolase 1 (hARH1, ADPRH) cleaves the glycosidic bond of ADP-ribose attached to an Arg residue of a protein. hARH1 has been cloned, expressed heterologously in Escherichia coli, purified and crystallized in complex with K(+) and ADP. The orthorhombic crystals contained one monomer per asymmetric unit, exhibited a solvent content of 43% and diffracted X-rays to a resolution of 1.9 A. A prerequisite for obtaining well diffracting crystals was the performance of X-ray fluorescence analysis on poorly diffracting apo hARH1 crystals, which revealed the presence of trace amounts of K(+) in the crystal. Adding K-ADP to the crystallization cocktail then resulted in a crystal of different morphology and with dramatically improved diffraction properties. PMID:19407395

Kernstock, Stefan; Koch-Nolte, Friedrich; Mueller-Dieckmann, Jochen; Weiss, Manfred S; Mueller-Dieckmann, Christoph

2009-04-28

375

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

NASA Astrophysics Data System (ADS)

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.

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

2010-04-01

376

Investigation by laser induced breakdown spectroscopy, X-ray fluorescence and X-ray powder diffraction of the chemical composition of white clay ceramic tiles from Veliki Preslav  

NASA Astrophysics Data System (ADS)

The paper presents the results of the application of laser induced breakdown spectroscopy, X-ray fluorescence spectrometry, and X-ray powder diffraction in assessing the chemical and phase composition of white clay decorative ceramic tiles from the medieval archaeological site of Veliki Preslav, a Bulgarian capital in the period 893-972 AC, well-known for its original ceramic production. Numerous white clay ceramic tiles with highly varied decoration, produced for wall decoration of city's churches and palaces, were found during the archaeological excavations in the old capital. The examination of fourteen ceramic tiles discovered in one of the city's monasteries is aimed at characterization of the chemical profile of the white-clay decorative ceramics produced in Veliki Preslav. Combining different methods and comparing the obtained results provides complementary information regarding the white-clay ceramic production in Veliki Preslav and complete chemical characterization of the examined artefacts.

Blagoev, K.; Grozeva, M.; Malcheva, G.; Neykova, S.

2013-01-01

377

Characterization of the Carancas-Puno meteorite by energy dispersive X-ray fluorescence, X-ray diffractometry and transmission Mössbauer spectroscopy  

NASA Astrophysics Data System (ADS)

We report the results of the study of a meteorite that impacted an inhabited zone on 15 September 2007 in the neighborhood of the town of Carancas, Puno Region, about 1,300 km south of Lima. The analysis carried out by energy dispersive X-ray fluorescence, X-ray diffractometry and transmission Mössbauer spectroscopy (at room temperature and at 4.2 K), reveal the presence in the meteorite sample of magnetic sites assigned to taenite (Fe,Ni) and troilite (Fe,S) phases, and of two paramagnetic doublets assigned to Fe2 + , one associated with olivine and the other to pyroxene. In accord with these results, this meteorite is classified as a type IV chondrite meteorite.

Cerón Loayza, María L.; Bravo Cabrejos, Jorge A.

2011-11-01

378

X-ray polarizer based on Kumakhov optics  

Microsoft Academic Search

The use of polarized x-ray beams provides drastic reduction of background connected with Compton scattering from the sample under investigation. In conventional x-ray tubes with isotropic distribution of x rays, the intensity of polarized beam after polarizer is very small. We have carried out the experiment with Kumakhov lens and Barcla polarizer to receive intense x-ray polarized beams. X-ray fluorescent

Vladimir P. Petukhov; Svetlana V. Nikitina

1997-01-01

379

Remote 1-MeV flash x-ray head experiment  

SciTech Connect

This document, Appendix B, contains engineering drawings for the TITAN remote tube head. High voltage cable connectors and flanges are included. The main report presents results from the 1 MeV flash x-ray head experiment.

Lancaster, K.T. (Titan Technologies, Albuquerque, NM (United States). Spectron Div.)

1991-12-09

380

Remote 1MeV flash x-ray head experiment  

Microsoft Academic Search

This document, Appendix B, contains engineering drawings for the TITAN remote tube head. High voltage cable connectors and flanges are included. The main report presents results from the 1 MeV flash x-ray head experiment.

1991-01-01

381

Remote 1MeV flash x-ray head experiment. Final report  

Microsoft Academic Search

This document, Appendix B, contains engineering drawings for the TITAN remote tube head. High voltage cable connectors and flanges are included. The main report presents results from the 1 MeV flash x-ray head experiment.

1991-01-01

382

[Determination of major elements in soil from cancer village by X-ray fluorescence spectrometry].  

PubMed

Many social problems arise from environmental pollution, cancer village is one of the many important problems caused by pollution. The authors selected a typical cancer village where 80-100 people died of cancer in the last five years, but there are only a total of 1 200 people in this village. The authors sampled soils from crops-planted areas and detected the major elements by X-ray fluorescence spectrometry. The results showed that the contents of SiO2, TiO2, Al2O3, Fe2O3, MnO, MgO, CaO, Na2O, K2O and P2O5 in soil of this village were 66.05%, 0.66%, 11.37%, 3.93%, 0.075%, 1.97%, 5.47%, 1.90%, 2.11% and 0.20% respectively; with the precision being +/- 0.20%, +/- 0.005%, +/- 0.10%, +/- 0.10%, +/- 0.005%, +/- 0.05%, +/- 0.04%, +/- 0.08%, +/- 0.02% and +/- 0.005% respectively, which showed that X-ray fluorescence spectrometry is a good method. PMID:19271523

Wei, Zhen-Lin; Li, He; Rui, Yu-Kui

2008-11-01

383

Determination of trace elements in rainwater by total-reflection X-ray fluorescence  

SciTech Connect

Three quasi-independent analytical procedures for the determination of trace elements in rainwater are presented, which are based on total-reflection X-ray fluorescence (TXRF), a special variant of energy-dispersive X-ray fluorescence. The three sample preparation techniques compared are (1) direct analysis, (2) preenrichment of the trace elements in rainwater by freeze-drying and redissolution in dilute nitric acid, and (3) a matrix removal and preconcentration procedure by metal chelation, chromatographic adsorption of the metal complexes, and subsequent elution of the metal chelates prior to TXRF measurement. The elements determined are S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Pb, Se, Rb, Sr, Mo, Cd, and Ba. For a measuring time of 1000 s, detection limits down to 5-20 ng/L were achieved for the heavy-metal traces. The limits are slightly higher for iron, nickel, copper, zinc, and lead because of fluctuations in the blan values. The procedures were tested on rainwater samples from the Island of Pellworm (German Bight) containing comparatively low trace-metal contents. Systematic investigations for the characterization of the analytical procedures with regard to blanks, detection limits, precision, and accuracy are described and discussed. The accuracy was checked by independent analyses of duplicate samples using differential pulse anodic stripping voltammetry (KFA Juelich). 17 references, 4 figures, 2 tables.

Stoessel, R.P.; Prange, A.

1985-12-01

384

Alloy nanowires bar codes based on nondestructive X-ray fluorescence readout.  

PubMed

We demonstrate here the ability to generate ternary Co-Ni-Cu alloy nanowires with distinct X-ray fluorescence (XRF) barcode patterns using a one-step template-guided electrodeposition. Such coupling of one-step templated synthesis with a nondestructive XRF readout of the composition patterns greatly simplifies practical applications of barcoded nanomaterials. The new protocol leads to alloy nanowires with broad composition range and hence to an extremely large number of distinguishable XRF signatures. The resulting fluorescence barcodes correlate well with the composition of the metal mixture plating solution, indicating a reproducible plating processes. Factors affecting the coding capacity and identification accuracy are examined, and potential tracking and authenticity applications involving embedding the nanowires within plastics or inks are demonstrated and discussed. PMID:17715995

Sattayasamitsathit, Sirilak; Burdick, Jared; Bash, Ralph; Kanatharana, Proespichaya; Thavarungkul, Panote; Wang, Joseph

2007-08-24

385

Natural speciation of Zn at the micrometer scale in a clayey soil using X-ray fluorescence, absorption, and diffraction  

Microsoft Academic Search

Combined use of synchrotron-based X-ray fluorescence (SXRF), diffraction (XRD), and absorption (EXAFS) with an X-ray spot size as small as five micrometers allows us to examine noninvasively heterogeneous soils and sediments. Specifically, the speciation of trace metals at low bulk concentrations and the nature of host minerals can be probed with a level of detail unattainable by other techniques. The

Alain Manceau; Matthew A. Marcus; Nobumichi Tamura; Olivier Proux; Nicolas Geoffroy; Bruno Lanson

2004-01-01

386

Optimizing the Elemental Sensitivity and Focal Spot Size of a Monolithic Polycapillary Optic Using Micro-X-Ray Fluorescence  

Microsoft Academic Search

A commercial micro-X-ray fluorescence (MXRF) instrument with an aperture X-ray guide was used to compare elemental sensitivities and focal spot sizes with those obtained by focusing the source with a monolithic polycapillary optic retrofitted into the system. The capillary provided an intensity gain of 125 at 4 keV vs. using a pinhole beam collimator; however, this gain advantage declined with

C. Worley; G. Havrilla; N. Gao; Q.-F. Xia

1998-01-01

387

Effect of powder sample granularity on fluorescent intensity and on thermal parameters in x-ray diffraction Rietveld analysis  

Microsoft Academic Search

The effect of sample granularity on diffracted x-ray intensity was evaluated by measuring the 2θ dependence of x-ray fluorescence from various samples. Measurements were made in the symmetric geometry on samples ranging from single crystals to highly absorbing coarse powders. A characteristic shape for the absorption correction was observed. A demonstration of the sensitivity of Rietveld refined site occupation parameters

C. J. Sparks; E. D. Specht; G. E. Ice; R. Kumar; P. Zschack; T. Shiraishi; K. Hisatsune

1991-01-01

388

Real-Time Studies of Gallium Adsorption and Desorption Kinetics by Grazing-Incidence Small-Angle X-ray Scattering and X-ray Fluorescence  

SciTech Connect

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.

Wang, Y.; Ozcan, A; Ludwig, K; Bhattacharyya, A

2008-01-01

389

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

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.

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

390

Development of a Scanning X-ray Fluorescence Microscope Using Size-Controllable Focused X-ray Beam from 50 to 1500nm  

SciTech Connect

In scanning X-ray microscopy, focused beam intensity and size are very important from the viewpoints of improvements of various performances such as sensitivity and spatial resolution. The K-B mirror optical system is considered to be the most promising method for hard X-ray focusing, allowing highly efficient and energy-tunable focusing. We developed focusing optical system using K-B mirrors where the focused beam size is controllable within the range of 50 - 1500 nm. The focused beam size and beam intensity can be adjusted by changing the source size, although beam intensity and size are in a trade-off relationship. This controllability provides convenience for microscopy application. Diffraction limited focal size is also achieved by setting the source size to 10 {mu}m. Intracellular elemental mappings at the single-cell level were performed to demonstrate the performance of the scanning X-ray fluorescence microscope equipped with the optical system at the BL29XUL of SPring-8. We will show magnified elemental images with spatial resolution of {approx}70 nm.

Matsuyama, Satoshi; Mimura, Hidekazu; Yumoto, Hirokatsu; Katagishi, Keiko; Handa, Soichiro; Shibatani, Akihiko; Sano, Yasuhisa; Yamauchi, Kazuto [Department of Precision Science and Technology, Graduate School of Engineering, Osaka University, Yamada-oka 2-1, Suita, Osaka 565-0871 (Japan); Yamamura, Kazuya; Endo, Katsuyoshi; Mori, Yuzo [Research Center for Ultra-Precision Science and Technology, Graduate School of Engineering, Osaka University, Yamada-oka 2-1, Suita, Osaka 565-0871 (Japan); Nishino, Yoshinori; Tamasaku, Kenji [SPring-8/RIKEN, Kouto 1-1-1, Mikazuki, Hyogo 679-5148 (Japan); Yabashi, Makina [SPring-8/Japan Synchrotron Radiation Research Institute (JASRI), Kouto 1-1-1, Mikazuki, Hyogo 679-5148 (Japan); Ishikawa, Tetsuya [SPring-8/Japan Synchrotron Radiation Research Institute (JASRI), Kouto 1-1-1, Mikazuki, Hyogo 679-5148 (Japan); SPring-8/RIKEN, Kouto 1-1-1, Mikazuki, Hyogo 679-5148 (Japan)

2007-01-19

391

X-ray Split and Delay System for Soft x-ray Pump/Probe Experiments at the LCLS Free Electron Laser  

NASA Astrophysics Data System (ADS)

We will report on the development of a mirror based x-ray split and delay system (XRSD) for soft x-rays at the Linac Coherent Light Source free electron laser. This device will be used for x-ray pump, x-ray probe experiments in gas-phase as well as solid state using the LCLS femtosecond photon beam. The XRSD system will be positioned after the Kirkpatrick-Baez focusing mirrors, delivering two pulses with a variable delay to the interaction chamber. Delay of 0-100 femtoseconds can be produced with resolution under 100 attoseconds. The energy in each pulse will be measured shot to shot. The XRSD is expected to be ready for user experiments in early 2012.

Murphy, Brendan; Bozek, John; Castagna, Jean-Charles; Berrah, Nora

2011-06-01

392

Simultaneous, coaxial neutron and x-ray imaging of inertial confinement fusion experiments at Omega  

NASA Astrophysics Data System (ADS)

The campaign to understand the dynamics of implosions in inertial confinement fusion experiments has generated a desire to compare neutron and x-ray images of the assembled targets. Several diagnostics currently exist, both at the Omega laser and the National Ignition Facility, which provide either neutron or x-ray radiography capabilities. However, these diagnostics view the target from different angles, and there is no verifiable co-registration of the images they produce. A system has therefore been developed to produce neutron and x-ray images simultaneously, through the same aperture and with the same view of the target. Recent experiments at the Omega laser have demonstrated this technique; the results are presented, and compared to images from other x-ray diagnostics, and to images generated with radiation-hydrodynamic simulations.

Danly, Christopher; Grim, Gary; Guler, Nevzat; Intrator, Miranda; Merrill, Frank; Volegov, Petr; Wilde, Carl

2012-10-01

393

Hard X-ray microbeam experiment at the Tristan main ring test beamline of the KEK.  

PubMed

A hard X-ray microbeam with zone-plate optics has been tested at the MR-BW-TL beamline on the Tristan main ring of the KEK, and preliminary experiments on scanning microscopy have also been performed. A sputtered-sliced Fresnel zone plate with an Au core and Ag/C multilayer is used as an X-ray focusing device. The outermost zone width of the zone plate is 0.25 microm. A focused spot size of approximately 0.5 mum has been achieved at an X-ray energy of 8.54 keV. In a scanning X-ray microscopy experiment, test patterns with submicrometer fine structure have been clearly resolved. PMID:16699208

Suzuki, Y; Kamijo, N; Tamura, S; Handa, K; Takeuchi, A; Yamamoto, S; Sugiyama, H; Ohsumi, K; Ando, M

1997-03-01

394

Optical and X-ray fluorescence spectroscopy studies of bone and teeth in newborn rats after maternal treatment with indinavir.  

PubMed

An experiment estimating influence of antiviral drug indinavir treatment during pregnancy on bones and teeth development in newborn rats was performed. Two different fluorescence noninvasive spectroscopy techniques, i.e. laser (407 nm)-induced fluorescence method to characterize the organic fluorescent molecules and X-ray fluorescence analysis to determine mineral components were used to study the surface response of femur, mandible and incisor during their formation in the first month of a rat's life. Differences in autofluorescence depending on the form of the bone were observed on the basis of the emission from enamel in 7-, 14- and 28-day-old newborn rats. The dependence between decrease in intensity of fluorescence and increase in mineralization with age in newborn rats was observed. An enhancement of the autofluorescence and a decrease in the concentration of Ca as a main element, as well as disturbances in the concentration of Zn as trace element were observed for bone as well as teeth in newborns during the first month of their life after maternal administration of indinavir (500 mg kg(-1) p.o.) in comparison with the control group. The results indicate that indinavir causes a delay in development of the skeleton and teeth in newborn rats. PMID:19906096

Drzazga, Zofia; Michalik, Katarzyna; Maciejewska, Karina; Kaszuba, Micha?; Nowi?ska, Barbara; Trzeciak, Hanna

2009-11-10

395

In Situ Experiments with X ray Tomography: an Attractive Tool for Experimental Mechanics  

Microsoft Academic Search

This paper aims at illustrating the potential of X-ray tomography for studying the mechanical behaviour of materials through\\u000a in situ experiments. Typical experimental tomography set ups which use laboratory and synchrotron X ray sources are described; advantages\\u000a and limitations of both types of sources are presented. Dedicated experimental devices which allow deformation and\\/or temperature\\u000a changes to be applied to various

J.-Y. Buffiere; E. Maire; J. Adrien; J.-P. Masse; E. Boller

2010-01-01

396

Modeling and experiments of x-ray ablation of National Ignition Facility first wall materials  

Microsoft Academic Search

This paper discusses results of modeling and experiments on the x-ray response of selected materials relevant to the NIF target chamber design. X-ray energy deposition occurs in such small characteristic depths (on the order of a micron) that thermal conduction and hydrodynamic motion significantly affect the material response, even during the typical 10-ns pulses. The finite-difference ablation model integrates four

A. T. Anderson; A. K. Burnham; M. T. Tobin; P. F. Peterson

1996-01-01

397

Historical description of selected experiments in the early development of x-ray optics  

Microsoft Academic Search

The pioneering experiments in x-ray optics that took place in the 1940s and 1950s at Stanford University, the University of Redlands, and the Smithsonian Astrophysical Observatory are described. The original work of Paul Kirkpatrick and his students had as its objective the design and construction of grazing incidence x-ray microscopes, but Gabor's work in microscopy by reconstructed wavefronts led to

Albert V. Baez

1992-01-01

398

Measuring lead, mercury, and uranium by in vivo X-ray fluorescence  

NASA Astrophysics Data System (ADS)

X-ray fluorescence (XRF) has been demonstrated to be a useful technique for measuring trace quantities of heavy metals in various tissues within the body. This thesis investigates a means of improving the measurement of lead in bone, as well as increasing the existing sensitivity of measuring kidney mercury content. The XRF measurement of uranium is also explored. This work assesses the feasibility of a normalisation method for the 57Co/90° system, in relating detected signal to the lead content of the sample. The feasibility of normalisation has been shown, which reduces subject dose and improves system transportability, as well as removes subjectivity, by eliminating the need for acquiring planar x-ray images of the measurement site. In the measurement of renal mercury concentrations, a gain in sensitivity increasing the x-ray tube operating voltage of the current system is investigated. It found that 250 kV, rather than 175 kV, and a titanium rather than uranium filter, results in a 2.5 +/- 0.2 times gain in sensitivity. This potential improvement could have profound clinical implications for the accuracy of occupational monitoring, and for assessing whether there is a quantitative relationship between biological fluid levels and mercury content in this critical organ. The XRF measurement of bone uranium content is also explored. Both source-excited and polarised systems have been developed, however, the sensitivity is currently beyond that which is useful for occupational monitoring of exposure to this toxin. The particular case of measuring uranium in survivors of "Friendly Fire" incidents (from Operation Desert Storm) is investigated, and the first detectable quantity of uranium has been observed in a member of this cohort, with the XRF system designed and built during the course of this work.

O'Meara, Joanne Michelle

399

C-library raft : Reconstruction algorithms for tomography. Applications to X-ray fluorescence tomography  

NASA Astrophysics Data System (ADS)

There are many reconstruction algorithms for tomography, raft for short, and some of them are considered "classic" by researchers. The so-called raft library, provide a set of useful and basic tools, usually needed in many inverse problems that are related to medical imaging. The subroutines in raft are free software and written in C language; portable to any system with a working C compiler. This paper presents source codes written according to raft routines, applied to a new imaging modality called X-ray fluorescence tomography. Program summary Program title: raft Catalogue identifier: AEJY_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEJY_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public Licence, version 2 No. of lines in distributed program, including test data, etc.: 218?844 No. of bytes in distributed program, including test data, etc.: 3?562?902 Distribution format: tar.gz Programming language: Standard C. Computer: Any with a standard C compiler Operating system: Linux and Windows Classification: 2.4, 2.9, 3, 4.3, 4.7 External routines: raft: autoconf 2.60 or later - http://www.gnu.org/software/autoconf/ GSL scientific library - http://www.gnu.org/software/gsl/ Confuse parser library - http://www.nongnu.org/confuse/ raft-fun: gengetopt - http://www.gnu.org/software/gengetopt/gengetopt.html Nature of problem: Reconstruction algorithms for tomography, specially in X-ray fluorescence tomography. Solution method: As a library, raft covers the standard reconstruction algorithms like filtered backprojection, Novikov's inversion, Hogan's formula, among others. The input data set is represented by a complete sinogram covering a determined angular range. Users are allowed to set solid angle range for fluorescence emission at each algorithm. Running time: 1 second to 15 minutes, depending on the data size.

Miqueles, Eduardo X.; de Pierro, Alvaro R.

2011-12-01

400

Experimental demonstration of direct L-shell x-ray fluorescence imaging of gold nanoparticles using a benchtop x-ray source  

PubMed Central

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/cm3 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 cm3 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?2 cm3). 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.

Manohar, Nivedh; Reynoso, Francisco J.; Cho, Sang Hyun

2013-01-01

401

Imaging metals in proteins by combining electrophoresis with rapid x-ray fluorescence mapping.  

SciTech Connect

Growing evidence points toward a very dynamic role for metals in biology. This suggests that physiological circumstance may mandate metal ion redistribution among ligands. This work addresses a critical need for technology that detects, identifies, and measures the metal-containing components of complex biological matrixes. We describe a direct, user-friendly approach for identifying and quantifying metal?protein adducts in complex samples using native- or SDS-PAGE, blotting, and rapid synchrotron X-ray fluorescence mapping with micro-XANES (X-ray absorption near-edge structure) of entire blots. The identification and quantification of each metal bound to a protein spot has been demonstrated, and the technique has been applied in two exemplary cases. In the first, the speciation of the in vitro binding of exogenous chromium to blood serum proteins was influenced markedly by both the oxidation state of chromium exposed to the serum proteins and the treatment conditions, which is of relevance to the biochemistry of Cr dietary supplements. In the second case, in vivo changes in endogenous metal speciation were examined to probe the influence of oxygen depletion on iron speciation in Shewanella oneidensis.

Finney, L.; Chishti, Y.; Khare, T.; Giometti, C.; Levina, A.; Lay, P. A.; Vogt, S.; Univ. of Sydney; Northwestern Univ.

2010-01-01

402

In vivo monitoring of toxic metals: assessment of neutron activation and x-ray fluorescence techniques  

SciTech Connect

To date, cadmium, lead, aluminum, and mercury have been measured in vivo in humans. The possibilities of monitoring other toxic metals have also been demonstrated, but no human studies have been performed. Neutron activation analysis appears to be most suitable for Cd and Al measurements, while x-ray fluorescence is ideally suited for measurement of lead in superficial bone. Filtered neutron beams and polarized x-ray sources are being developed which will improve in vivo detection limits. Even so, several of the current facilities are already suitable for use in epidemiological studies of selected populations with suspected long-term low-level ''environmental'' exposures. Evaluation and diagnosis of patients presenting with general clinical symptoms attributable to possible toxic metal exposure may be assisted by in vivo examination. Continued in vivo monitoring of industrial workers, especially follow-up measurements, will provide the first direct assessment of changes in body burden and a direct measure of the biological life-times of these metals in humans. 50 refs., 4 figs., 2 tabs.

Ellis, K.J.

1986-01-01

403

High Zn content of Randall's plaque: a ?-X-ray fluorescence investigation.  

PubMed

Kidney stone disease, or nephrolithiasis, is a common ailment. Among the different risk factors usually associated with nephrolithiasis are dehydration, metabolic defects (especially with regard to calcium and oxalate). The presence of a mineral deposit at the surface of the renal papilla (termed Randall's plaque) has all been recently underlined. Of note, Randall's plaque is made of the calcium phosphate, carbapatite, and serves as a nucleus for kidney stone formation. The process by which apatite nanocrystals nucleate and form Randall's plaque remains unclear. This paper deals with the possible relationship between trace elements and the formation of this mineral. The investigation has been performed on a set of Randall's plaques, extracted from human kidney stones, through ?-X-ray diffraction and ?-X-ray fluorescence analyses in order to determine the chemical composition of the plaque as well as the nature and the amount of trace elements. Our data provide evidence that Zn levels are dramatically increased in carbapatite of RP by comparison to carbapatite in kidney stones, suggesting that calcified deposits within the medullar interstitium are a pathological process involving a tissue reaction. Further studies, perhaps including the investigation of biomarkers for inflammation, are necessary for clarifying the role of Zn in Randall's plaque formation. PMID:21763116

Carpentier, Xavier; Bazin, Dominique; Combes, Christelle; Mazouyes, Aurélie; Rouzičre, Stephan; Albouy, Pierre Antoine; Foy, Eddy; Daudon, Michel

2011-07-16

404

Synchrotron-based X-ray fluorescence imaging and elemental mapping from biological samples  

SciTech Connect

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.

D Rao; M Swapna; R Cesareo; A Brunetti; T Akatsuka; T Yuasa; T Takeda; G Gigante

2011-12-31

405

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

NASA Astrophysics Data System (ADS)

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 (ľ-XRF) and micro-X-ray absorption fine structure (ľ-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.

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

2013-06-01

406

Development of a Time-resolved Soft X-ray Spectrometer for Laser Produced Plasma Experiments  

SciTech Connect

A 2400 line/mm variable spaced grating spectrometer (VSG) has been used to measure soft x-ray emission (8-22 {angstrom}) from laser-produced plasma experiments at Lawrence Livermore National Laboratory's Compact Multipulse Terrawatt (COMET) Laser Facility. The spectrometer was coupled to a Kentech x-ray streak camera to study the temporal evolution of soft x-rays emitted from the back of mylar and copper foils irradiated at 10{sup 15} W/cm{sup 2}. The instrument demonstrated a resolving power of {approx} 120 at 19 {angstrom} with a time resolution of 31 ps. The time-resolved copper emission spectrum was consistent with a photodiode monitoring the laser temporal pulse shape and indicated that the soft x-ray emission follows the laser heating of the target. The time and spectral resolution of this diagnostic make it useful for studies of high temperature plasmas.

Cone, K V; Dunn, J; Schneider, M B; Baldis, H A; Brown, G V; Emig, J; James, D L; May, M J; Park, J; Shepherd, R; Widmann, K

2010-05-12

407

Optimizing the operation of a high resolution vertical Johann spectrometer using a high energy fluorescer x-ray source  

SciTech Connect

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/{Delta}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.

Haugh, Michael [National Security Technologies, LLC, 161 S. Vasco Rd., Suite A, Livermore, California 94550 (United States); Stewart, Richard [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94550 (United States)

2010-10-15

408

The Maia detector array and x-ray fluorescence imaging system: locating rare precious metal phases in complex samples  

NASA Astrophysics Data System (ADS)

X-ray fluorescence images acquired using the Maia large solid-angle detector array and integrated real-time processor on the X-ray Fluorescence Microscopy (XFM) beamline at the Australian Synchrotron capture fine detail in complex natural samples with images beyond 100M pixels. Quantitative methods permit real-time display of deconvoluted element images and for the acquisition of large area XFM images and 3D datasets for fluorescence tomography and chemical state (XANES) imaging. This paper outlines the Maia system and analytical methods and describes the use of the large detector array, with a wide range of X-ray take-off angles, to provide sensitivity to the depth of features, which is used to provide an imaging depth contrast and to determine the depth of rare precious metal particles in complex geological samples.

Ryan, C. G.; Siddons, D. P.; Kirkham, R.; Li, Z. Y.; de Jonge, M. D.; Paterson, D.; Cleverley, J. S.; Kuczewski, A.; Dunn, P. A.; Jensen, M.; De Geronimo, G.; Howard, D. L.; Godel, B.; Dyl, K. A.; Fisher, L. A.; Hough, R. H.; Barnes, Stephen J.; Bland, P. A.; Moorhead, G.; James, S. A.; Spiers, K. M.; Falkenberg, G.; Boesenberg, U.; Wellenreuther, G.

2013-09-01

409

Quantitative Determination of Sulfur, Chlorine, Potassium, Calcium, Scandium and Titanium in Aqueous Solutions by Radioisotopic Excited Fluorescent Spectrometer and by Conventional X-Ray Spectrometer.  

National Technical Information Service (NTIS)

An x-ray spectrometer with experimental results is herewith described using a radioisotope source Fe55 having a half-life of 2.6 years. As a result of the disintegration, the managanese x-rays are capable of exciting fluorescent x-rays of such elements as...

F. L. Chan W. B. Jones

1971-01-01

410

THE SEPARATION AND FLUORESCENT X-RAY SPECTROMETRIC DETERMINATION OF ZIRCONIUM, MOLYBDENUM, RUTHENIUM, RHODIUM, AND PALLADIUM IN SOLUTION IN URANIUM-BASE FISSIUM ALLOYS  

Microsoft Academic Search

The various elements are separated prior to the fluorescent x-ray ; determination because of either direct x-ray line interference or negative ; interference to the characteristic x-ray intensities caused by the presence of ; the other elements in the solution. Palladium is precipitated with ; dimethylglyoxime, and the precipitate is extracted with chloroform. The aqueous ; portion is made 6M

J. O. Karttunen

1963-01-01

411

Experimental Verification of Moseley's Law and the Measurement of Environmental, Pollution, and Biological Samples using X-Ray Fluorescence analysis  

NASA Astrophysics Data System (ADS)

X-rays are in general known to follow Moseley's Law. He provided the first concrete experimental evidence in favor of Bohr's theory of the atom. His major discovery was that there is a systematic mathematical relationship between the X-ray produced by the target and the atomic number of the target. This relationship became known as Moseley's Law and just think he was only 25 years old when he made this discovery. Moseley's Law states that the frequency of the K? radiation is given by: f K? =3cR4(Z-1)^2 where c is the velocity of light and R is the Rydberg constant. Therefore a plot of the square root of frequency of the K?line versus the atomic number of the element should be a straight line. A similar plot for the K?1 line also yields a straight line. In this poster we will show the X-ray fluorescence measurement of a variety of environmental, pollution and biological samples. The X-rays from these samples were excited with an X-ray tube and radioactive sources which gives experimental verification of Moseley's Law and X-ray fluorescence measurement.

Kummari, Venkata; Naik, Sahil; Patnaik, Ritish; Duggan, Jerome; Rout, Bibhudutta

2010-10-01

412

In-situ assessment of metal contamination via portable X-ray fluorescence spectroscopy: Zlatna, Romania.  

PubMed

Zlatna, Romania is the site of longtime mining/smelting operations which have resulted in widespread metal pollution of the entire area. Previous studies have documented the contamination using traditional methods involving soil sample collection, digestion, and quantification via inductively coupled plasma atomic emission spectroscopy or atomic absorption. However, field portable X-ray fluorescence spectroscopy (PXRF) can accurately quantify contamination in-situ, in seconds. A PXRF spectrometer was used to scan 69 soil samples in Zlatna across multiple land use types. Each site was georeferenced with data inputted into a geographic information system for high resolution spatial interpolations. These models were laid over contemporary aerial imagery to evaluate the extent of pollution on an individual elemental basis. Pb, As, Co, Cu, and Cd exceeded governmental action limits in >50% of the sites scanned. The use of georeferenced PXRF data offers a powerful new tool for in-situ assessment of contaminated soils. PMID:23906556

Weindorf, David C; Paulette, Laura; Man, Titus

2013-07-29

413

Determination of silicon in organic matrices with grazing-emission X-ray fluorescence spectrometry  

NASA Astrophysics Data System (ADS)

The potential of a prototype grazing-emission X-ray fluorescence spectrometer for reliable analysis of sample solutions, obtained by pressurized microwave oven digestion of Si-spiked organic and biological materials, was investigated as part of an inter-laboratory study. The fact that this grazing-emission technique is based on the total reflection phenomenon and wavelength-dispersive detection, gives it the benefit to determine light elements in a sensitive way. Results of the determination of silicon in pork liver, cellulose, urine, serum, spinach, beer, mineral water and horsetail (dry plant extract) samples are presented. Some of the results are compared with those obtained with other analytical techniques. The study proved that determination of silicon traces in biological matrices represents an extremely difficult task, however, measurements of silicon are achieved with acceptable precision. The most important problems still arise when sample pre-treatment is needed prior to analysis.

Claes, M.; Van Dyck, K.; Deelstra, H.; Van Grieken, R.

1999-10-01

414

Unique Properties of Thermally Tailored Copper: Magnetically Active Regions and Anomalous X-ray Fluorescence Emissions.  

PubMed

When high-purity copper (>/=99.98%(wt)) is melted, held in its liquid state for a few hours with iterative thermal cycling, then allowed to resolidify, the ingot surface is found to have many small regions that are magnetically active. X-ray fluorescence analysis of these regions exhibit remarkably intense lines from "sensitized elements" (SE), including in part or fully the contiguous series V, Cr, Mn, Fe, and Co. The XRF emissions from SE are far more intense than expected from known impurity levels. Comparison with blanks and standards show that the thermal "tailoring" also introduces strongly enhanced SE emissions in samples taken from the interior of the copper ingots. For some magnetic regions, the location as well as the SE emissions, although persistent, vary irregularly with time. Also, for some regions extraordinarily intense "sensitized iron" (SFe) emissions occur, accompanied by drastic attenuation of Cu emissions. PMID:20037657

Nagel, Christopher J; Herschbach, Dudley R

2009-11-19

415

Validation of X-ray fluorescence-measured Swine femur lead against atomic absorption spectrometry.  

PubMed Central

The aim of this study was to apply the technique of (109)Cd-based K-shell X-ray fluorescence (XRF) bone lead measurements to swine femurs and to validate the concentrations obtained therefrom against an independent chemical measurement of bone lead: atomic absorption spectrometry (AAS). The femurs ranged in lead concentration from 1.0 to 24.5 microg of lead per gram of ashed bone, as measured by AAS. On average, XRF overestimated AAS-measured femur lead by 2.6 microg/g [95% confidence interval (CI), 1.1-4.0 microg/g], approximately 2 microg/g poorer than that observed in studies of human tibiae. Measurements of swine femur and, by extension, of nonhuman bones may require adjustment of the XRF spectrum peak extraction method.

Todd, A C; Moshier, E L; Carroll, S; Casteel, S W

2001-01-01

416

Multielement analysis of soft drinks by X-ray fluorescence spectrometry.  

PubMed

Several commercial soft drinks and respective plastic bottles were analyzed for their multielement contents employing the synchrotron radiation total reflection X-ray fluorescence spectrometry technique (SRTXRF). The SRTXRF method has been developed and validated, and about 20 elements were detected in the investigated samples, including some trace elements, which can be toxic for human beings, such as Ti, Cr, Sb, As, and Pb in soft drinks and Al, Sb, As, and Pb in poly(ethylene terephthalate) (PET) containers. Statistical analysis was performed using chemometric techniques (principal component analysis and cluster analysis), and similarities were verified in the multielement contents of the samples. The results demonstrated that the SRTXRF offers a good multielemental approach for the quality control of food products. Moreover, on the basis of enrichment factors, the possibility of the trace elements in the PET container may be leached to the beverages under normal commercial situations and other results were discussed. PMID:16190643

Zucchi, Orghęda L A D; Moreira, Silvana; Salvador, Marcos J; Santos, Leandro L

2005-10-01

417

Validation of X-ray fluorescence spectrometry for determining osseous or dental origin of unknown material.  

PubMed

Forensic anthropological examinations typically involve the analysis of human skeletal remains, but in cases where samples are very small and/or physically compromised, it may first be necessary to determine whether the material is even osseous or dental in origin. X-ray fluorescence spectrometry (XRF) is a technique that reveals the elemental composition of materials and is hypothesized to have utility in such cases. XRF analysis was conducted on a variety of tissues and materials in unaltered and altered (damaged) states. With few exceptions, osseous and dental tissues in unaltered and altered conditions contained characteristic levels of calcium and phosphorus, while other materials did not. Materials could be accurately identified as osseous or dental in origin based on the calcium and phosphorus levels identified by XRF, and we therefore conclude that XRF analysis is a valid and effective means of determining osseous or dental origin of unknown material. PMID:22040159

Christensen, Angi M; Smith, Michael A; Thomas, Richard M

2011-10-31

418

Direct elemental analysis of cancer cell lines by total reflection X-ray fluorescence  

NASA Astrophysics Data System (ADS)

The elemental content of Cu, Fe and Zn in two human adenocarcinoma cell lines was investigated by total reflection X-ray fluorescence (TXRF) spectrometry. Cancer cells were sedimented directly to the quartz plates using a modified cytospin slide holder setup. Special glass stands and caps were also constructed to hold the quartz plates with the cells during the vapour-phase microwave assisted digestion. The method was validated by analysis of certified reference materials. The signal-to-noise ratio was optimized by washing the cells with different solutions. The technique was applied to the determination of Cu, Fe and Zn content of HT-29 and HCA-7 colorectal adenocarcinoma cell lines. Dry mass of the centrifuged cells were determined and the elemental analysis data reported for the two cell lines were referred either to cell numbers, to the total protein content or to the dry mass.

Szoboszlai, Norbert; Réti, Andrea; Budai, Barna; Szabó, Zsuzsa; Kralovánszky, Judit; Záray, Gyula

2008-12-01

419

Soil characterization by energy dispersive X-ray fluorescence: sampling strategy for in situ analysis.  

PubMed

This work describes a sampling strategy that will allow the use of portable EDXRF (energy dispersive X-ray fluorescence) instruments for "in situ" soil analysis. The methodology covers a general approach to planning field investigations for any type of environmental studies and it was applied for a soil characterization study in the zone of Campana, Argentina, by evaluating data coming from an EDXRF spectrometer with a radioisotope excitation source. Simulating non-treated sampled as "in situ" samples and a soil characterization for Campana area was intended. "In situ" EDXRF methodology is a powerful analytical modality with the advantage of providing data immediately, allowing a fast general screening of the soil composition. PMID:16038489

Custo, Graciela; Boeykens, Susana; Dawidowski, L; Fox, L; Gómez, D; Luna, F; Vázquez, Cristina

2005-07-01

420

Portable X-ray Fluorescence Spectrometry for the analyses of Cultural Heritage  

NASA Astrophysics Data System (ADS)

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.

Ridolfi, S.

2012-07-01

421

Petrographic, mineralogic, and x-ray fluorescence analysis of lunar igneous-type rocks and spherules.  

PubMed

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

Brown, G M; Emeleus, C H; Holland, J G; Phillips, R

1970-01-30

422

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

PubMed

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 a searchable spectral library was created. Due to the difference in the elemental composition of spray paints, a further discrimination was possible. The microscopic analysis was not taken into consideration for classification purposes. The structure of the substrate under a paint coating strongly affects the surface characteristics of this spray paint. Together with the spectral library, a database of information of spray paints was build. PMID:15013166

Govaert, Filip; Bernard, Magali

2004-02-10

423

[Determination of 12 elements in coal ash by x-ray fluorescence spectrometry].  

PubMed

A method for the determination of SiO2, Al2O3, Fe2O3, CaO, SO3, TiO2, K2O, Na2O, P2O5, MgO, MnO and BaO in coal ash by X-ray fluorescence spectrometry with melt sample preparation was developed. This method solved the problems of determination accuracy of S by using the 12:22 mix flux and oxide to lower the melt temperature. Using the soil standard sample and mixing the soil standard sample and coal ash standard sample solved the problem that there are not enough standard samples for coal ash analysis by XRF. The accuracy and precision of this method are acceptable, and the results are comparable to the those obtained by wet chemical method. PMID:18800742

Song, Yi; Guo, Fen; Gu, Song-hai

2008-06-01

424

Structure Refinement Based on Inverse Fourier Analysis in X-Ray Fluorescence Holography  

SciTech Connect

A new reconstruction technique for X-ray fluorescence hologram data was proposed based on extractions of holographic oscillations from single scatterers within a sample. The extractions were iteratively carried out by the inverse Fourier transformation of selected atomic images, which were obtained by the Fourier transformation of one-dimensional hologram averaged over azimuth about a given polar axis in k-space. The refinement of the real space reconstruction was performed using the measured holograms and the extracted holographic oscillations. I applied this data processing to the theoretical holograms of fcc Au cluster at 12.0, 12.5 and 13.0 keV, and successfully obtained clear atomic image without artifacts.

Hayashi, K. [Institute of Materials Research, Tohoku University, Sendai 980-8577 (Japan)

2007-01-19

425

Validation of X-ray fluorescence-measured Swine femur lead against atomic absorption spectrometry.  

PubMed

The aim of this study was to apply the technique of (109)Cd-based K-shell X-ray fluorescence (XRF) bone lead measurements to swine femurs and to validate the concentrations obtained therefrom against an independent chemical measurement of bone lead: atomic absorption spectrometry (AAS). The femurs ranged in lead concentration from 1.0 to 24.5 microg of lead per gram of ashed bone, as measured by AAS. On average, XRF overestimated AAS-measured femur lead by 2.6 microg/g [95% confidence interval (CI), 1.1-4.0 microg/g], approximately 2 microg/g poorer than that observed in studies of human tibiae. Measurements of swine femur and, by extension, of nonhuman bones may require adjustment of the XRF spectrum peak extraction method. PMID:11712995

Todd, A C; Moshier, E L; Carroll, S; Casteel, S W

2001-11-01

426

X-ray diffraction experiment - the last experiment in the structure elucidation process  

PubMed Central

Recent years have brought not only an avalanche of new macromolecular structures, but also significant advances in the protein structure determination methodology only now making its way into structure-based drug discovery. In this paper, we review recent methodology developments in X-ray diffraction experiments that lead to fast and very accurate elucidation of three-dimensional structures of macromolecules. We will discuss the role of data collection as the last experiment performed in the crystal structure determination process. A statistical analysis of diffraction experiments that are reported in the Protein Data Bank is also presented.

Chruszcz, Maksymilian; Borek, Dominika; Domagalski, Marcin; Otwinowski, Zbyszek; Minor, Wladek

2011-01-01

427

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

428

Trace Element Mapping of a Biological Specimen by a Full-Field X-ray Fluorescence Imaging Microscope with a Wolter Mirror  

SciTech Connect

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.

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

429

X-ray spectrometry using polycapillary X-ray optics and position sensitive detector  

Microsoft Academic Search

Polycapillary X-ray optics (capillary X-ray lens) are now popular in X-ray fluorescence (XRF) analysis. Such an X-ray lens can collect X-rays emitted from an X-ray source in a large solid angle and form a very intense X-ray microbeam which is very convenient for microbeam X-ray fluorescence (MXRF) analysis giving low minimum detection limits (MDLs) in energy dispersive X-ray fluorescence (EDXRF).

Xunliang Ding; Jingdong Xie; Yejun He; Quili Pan; Yiming Yan

2000-01-01

430

Bromide detection in blood using energy dispersive X-ray fluorescence; a chemical marker supportive of drowning in seawater.  

PubMed

Energy dispersive X-ray fluorescence spectrometry (EDX) enables rapid, non-destructive, multi-elemental analysis. Using EDX, bromide was detected in seawater but not in freshwater. We applied EDX to the detection of bromide in cardiac blood from medico-legal autopsy cases to obtain additional evidence supportive of seawater drowning. Bromide was detected in the blood of 4 out of 10 victims drowned in seawater. In contrast, bromide concentrations were below the quantification limit in both victims from freshwater drowning and non-drowning controls. No postmortem invasion of bromide was observed in animal experiments of postmortem immersion in seawater. These results indicate that the detection of bromide in blood by EDX could be a chemical marker supportive of drowning in seawater. PMID:20335061

Takahashi, Motonori; Kinoshita, Hiroshi; Nishiguchi, Minori; Nishio, Hajime

2010-03-23

431

Mercury dynamics in hair of rats exposed to methylmercury by synchrotron radiation X-ray fluorescence imaging  

SciTech Connect

Two dimensional distribution of mercury (Hg) in hair samples of rats exposed to methylmercury (MeHg) was analyzed by synchrotron radiation X-ray fluorescence (SR-XRF) imaging. Experiments with endogenous- and exogenous-model for MeHg exposure revealed that the metal level was obviously higher in the hair cortex after the former exposure whereas a dominant site that Hg distributed after the latter exposure was the cuticle. The method also provided us the Hg profile along the hair length with a single hair obtained by the endogenous model. Thus application of SR-XRF analysis to hair sample would facilitate biological monitoring to not only distinct Hg exposure but also determine its dynamics with only the specimen. 12 refs., 7 figs.

Shimojo, Nobuhiro; Homma-Takeda, Shino; Kumagai, Yoshito [Univ. of Tsukuba, Ibaraki (Japan)] [and others

1997-05-02

432

Progress in nuclear physics experiments for the study of X-ray bursts  

NASA Astrophysics Data System (ADS)

Neutron stars in close binary star systems often accrete matter from their companion star. Thermonuclear ignition of the accreted material in the atmosphere of the neutron star leads to a thermonuclear explosion which is observed as an X-ray burst occurring periodically between hours and days depending on the accretion rate. However, the underlying nuclear processes that power the X-ray bursts are often difficult to measure in accelerator-based laboratories. In this talk, I will discuss recent experimental progress in nuclear physics for the input of X-ray bursts model simulations. In particular, I will present new experiments on the measurements of nuclear breakout reactions from the hot CNO cycle that are critical to the ignition conditions of X-ray bursts. Recent measurements of reaction rates along the rp- and ?p- process path that determine the X-ray burst light curves will also be discussed. Astrophysical implications of the experimental results will be explored within the context of X-ray burst models.

Tan, Wanpeng

2008-04-01

433

Application of a high-resolution x-ray fluorescence analyzer.  

SciTech Connect

We have developed a high resolution x-ray fluorescence analyzer based on the principle of active optics. It combines a resolution of ca. 5 eV with a tunability over several keV and a wide solid-angle coverage (ca. 2 by 5 degrees). To date, this analyzer has been used in near-edge spectroscopy of gallium in GaAs, and for the detection and chemical speciation of trace amounts platinum in soot from an diesel engine. The latter application illustrates the use of the analyzer to enhance the signal-to-background ratio in trace-element x-ray fluorescence analysis. The analyzer is shown schematically in Fig. 1. In it, a strip of silicon is bent by an axial force from two pushers at its ends, and eight correctors act from above to bring the shape of the bent crystal to approximate a logarithmic spiral. A more detailed description of the device, its underlying theory, and adjustment procedures may be found elsewhere. The sample consisted of soot collected from the exhaust of a diesel engine burning a fuel with a platinum-based additive that was tested for the purpose of facilitating clean combustion. The concentration of platinum in the soot was about 100 ppm, and the chemical speciation (oxidation state, dispersed or in the form of nanoparticles, etc.) was unknown. A small speck of this soot containing 10{sup 12} to 10{sup 13} atoms was placed into the x-ray beam of the 11-ID-D station of the APS. The incident photon energy was scanned over the Pt L{sub 3} edge, and the Pt L{sub {alpha}1} fluorescence was detected using two silicon drift detectors (Vortex), one directly and one with the analyzer. The purpose of the analyzer in this application was to enhance the energy resolution by a factor of about 50 (250 eV for the drift detector, 5 eV for the analyzer), and thus reduce the background of elastically or Compton-scattered photons, while keeping the fluorescent line. Whereas the detector with the analyzer recorded a clear signature of platinum in the form of an absorption edge (see Fig. 2), the other one was overwhelmed by elastic and Compton scattering from the sample, and no indication of an edge was visible. Comparison of the near-edge spectrum with references of platinum metal, platinum oxide and platinum chloride measured during the same beamtime and with the same setup shows that the platinum in the soot sample is neither in its metallic state, nor an oxide, nor is it a mixture of the two (i.e., a linear combination of the metal and oxide spectra). The high-resolution fluorescence analyzer described here permits trace-element analysis at significantly lower concentration levels than previously possible with solid-state detectors. Apart from the background suppression demonstrated here, it is also capable of separating closely-spaced fluorescent lines, which is also highly important in trace-element analysis.

Adams, B. W.; Attenkofer, K.; Experimental Facilities Division (APS)

2006-01-01

434

Effects in K X-ray fluorescence spectra due to Compton scattering in the target  

NASA Astrophysics Data System (ADS)

In a previous study of our group, it has been shown that broad continua adjacent to the full-energy peaks (the “shoulders”) in the spectra of 59.537 keV ?-rays emitted from a standard Am241 calibration source are due to Compton scattering of ?-rays in the source plate (mass of only 0.59 g). An extension of that work is presented with the aim to show that the analogous shoulder spectra also appear in the K X-ray fluorescence spectra, and are due to the Compton scattering of fluorescence radiation in the target. The experimental set-up was carefully designed with the aim to strongly reduce single and double scattering of Am241 radiation from all surrounding materials except from the targets. An Am241 annular source was used to excite the fluorescence radiation. Measurements have been made with a target of parafine loaded with Ce2O3 and, for comparison, with a pure parafine target. To show that Compton scattering is the main cause of the observed shoulder spectra, the measurements were made for three orientations of the targets with respect to the detector-to-target centre-line. The observed changes in the measured spectra clearly show that the shoulders are mainly due to Compton scattering in the targets. Calculations of the shoulder spectra show a good agreement to the measured spectra.

Uroi?, M.; Majer, M.; Paši?, S.; Bokuli?, T.; Vukovi?, B.; Ilakovac, K.

2006-11-01

435

Internal elemental microanalysis combining x-ray fluorescence, Compton and transmission tomography  

NASA Astrophysics Data System (ADS)

Conventional x-ray transmission tomography provides the spatial distribution of the absorption coefficient inside a sample. Other tomographic techniques, based on the detection of photons coming from fluorescent emission, Compton and Rayleigh scattering, are used for obtaining information on the internal elemental composition of the sample. However, the reconstruction problem for these techniques is generally much more difficult than that of transmission tomography, mainly due to self-absorption effects in the sample. In this article an approach to the reconstruction problem is presented, which integrates the information from the three types of signals. This method provides the quantitative spatial distribution of all elements that emit detectable fluorescent lines (Z>=15 in usual experimental conditions), even when the absorption effects are strong, and the spatial distribution of the global density of the lighter elements. The use of this technique is demonstrated on the reconstruction of a grain of the martian meteorite NWA817, mainly composed of low Z elements not measured in fluorescence and for which this method provides a unique insight. The measurement was done at the ID22 beamline of the European Synchrotron Radiation Facility.

Golosio, Bruno; Simionovici, Alexandre; Somogyi, Andrea; Lemelle, Laurence; Chukalina, Marina; Brunetti, Antonio

2003-07-01

436

Note: Experiments in hard x-ray chemistry: in situ production of molecular hydrogen and x-ray induced combustion.  

PubMed

We have successfully loaded H(2) into a diamond anvil cell at high pressure using the synchrotron x-ray induced decomposition of NH(3)BH(3). In a second set of studies, radiation-assisted release of O(2) from KCLO(3), H(2) release from NH(3)BH(3), and reaction of these gases in a mixture of the reactants to form liquid water using x-rays at ambient conditions was observed. Similar observations were made using a KCLO(3) and NaBH(4) mixture. Depending on reaction conditions, an explosive or far slower reaction producing water was observed. PMID:22462968

Pravica, Michael; Bai, Ligang; Park, Changyong; Liu, Yu; Galley, Martin; Robinson, John; Hatchett, David

2012-03-01

437

High energy resolution five-crystal spectrometer for high quality fluorescence and absorption measurements on an x-ray absorption spectroscopy beamline  

SciTech Connect

Fluorescence detection is classically achieved with a solid state detector (SSD) on x-ray absorption spectroscopy (XAS) beamlines. This kind of detection however presents some limitations related to the limited energy resolution and saturation. Crystal analyzer spectrometers (CAS) based on a Johann-type geometry have been developed to overcome these limitations. We have tested and installed such a system on the BM30B/CRG-FAME XAS beamline at the ESRF dedicated to the structural investigation of very dilute systems in environmental, material and biological sciences. The spectrometer has been designed to be a mobile device for easy integration in multi-purpose hard x-ray synchrotron beamlines or even with a laboratory x-ray source. The CAS allows to collect x-ray photons from a large solid angle with five spherically bent crystals. It will cover a large energy range allowing to probe fluorescence lines characteristic of all the elements from Ca (Z = 20) to U (Z = 92). It provides an energy resolution of 1-2 eV. XAS spectroscopy is the main application of this device even if other spectroscopic techniques (RIXS, XES, XRS, etc.) can be also achieved with it. The performances of the CAS are illustrated by two experiments that are difficult or impossible to perform with SSD and the complementarity of the CAS vs SSD detectors is discussed.

Llorens, Isabelle [CEA/DSM/INAC/SP2M/NRS, F-38054 Grenoble cedex 9 (France); Synchrotron SOLEIL - MARS beamline, L'Orme des Merisiers, F-91192 Gif sur Yvette (France); Lahera, Eric; Delnet, William; Proux, Olivier [Observatoire des Sciences de l'Univers de Grenoble, UMS 832 CNRS Universite Joseph Fourier, F-38041 Grenoble cedex 9 (France); BM30B/FAME beamline, ESRF, F-38043 Grenoble cedex 9 (France); Braillard, Aurelien; Hazemann, Jean-Louis; Prat, Alain; Testemale, Denis [BM30B/FAME beamline, ESRF, F-38043 Grenoble cedex 9 (France); Institut Neel, UPR 2940 CNRS, F-38042 Grenoble cedex 9 (France); Dermigny, Quentin; Gelebart, Frederic; Morand, Marc; Shukla, Abhay [Institut de Mineralogie et de Physique des Milieux Condenses, UMR 7590, 4 place Jussieu, F-75005 Paris (France); Bardou, Nathalie [Laboratoire de Photonique et de Nanostructures, UPR 20 CNRS, Route de Nozay, F-91460 Marcoussis (France); Ulrich, Olivier [CEA/DSM/INAC/SP2M/NRS, F-38054 Grenoble cedex 9 (France); BM32/IF beamline, ESRF, F-38043 Grenoble cedex 9 (France); Arnaud, Stephan; Berar, Jean-Francois; Boudet, Nathalie; Caillot, Bernard [Institut Neel, UPR 2940 CNRS, F-38042 Grenoble cedex 9 (France); BM02/D2AM beamline, ESRF, F-38043 Grenoble cedex 9 (France); Chaurand, Perrine; Rose, Jerome [Centre Europeen de Recherche et d'Enseignement des Geosciences de l'Environnement, UMR 7730, F-13545 Aix en Provence (France); and others

2012-06-15

438

Iron speciation in human cancer cells by K-edge total reflection X-ray fluorescence-X-ray absorption near edge structure analysis  

NASA Astrophysics Data System (ADS)

X-ray absorption near edge structure (XANES) analysis in combination with synchrotron radiation induced total reflection X-ray fluorescence (SR-TXRF) acquisition was used to determine the oxidation state of Fe in human cancer cells and simultaneously their elemental composition by applying a simple sample preparation procedure consisting of pipetting the cell suspension onto the quartz reflectors. XANES spectra of several inorganic and organic iron compounds were recorded and compared to that of different cell lines. The XANES spectra of cells, independently from the phase of cell growth and cell type were very similar to that of ferritin, the main Fe store within the cell. The spectra obtained after CoCl 2 or NiCl 2 treatment, which could mimic a hypoxic state of cells, did not differ noticeably from that of the ferritin standard. After 5-fluorouracil administration, which could also induce an oxidative-stress in cells, the absorption edge position was shifted toward higher energies representing a higher oxidation state of Fe. Intense treatment with antimycin A, which inhibits electron transfer in the respiratory chain, resulted in minor changes in the spectrum, resembling rather the N-donor Fe-?,?'-dipyridyl complex at the oxidation energy of Fe(III), than ferritin. The incorporation of Co and Ni in the cells was followed by SR-TXRF measurements.

Polgári, Zs.; Meirer, F.; Sasamori, S.; Ingerle, D.; Pepponi, G.; Streli, C.; Rickers, K.; Réti, A.; Budai, B.; Szoboszlai, N.; Záray, G.

2011-03-01

439

Silver speciation in liver of marine mammals by synchrotron X-ray absorption fine structure and X-ray fluorescence spectroscopies.  

PubMed

The chemical form of Ag in the livers of five species of marine mammals was examined using X-ray absorption fine structure (XAFS) and X-ray fluorescence (XRF) spectroscopies. The XAFS analysis suggested that Ag(2)Se was present in the livers of the Franciscana dolphin (Pontoporia blainvillei), Dall's porpoise (Phocoenoides dalli), and Baird's beaked whale (Berardius bairdii), whereas Ag(2)S was present in the livers of the striped dolphin (Stenella coeruleoalba) and pygmy killer whale (Feresa attenuata). XRF spectroscopy results revealed that the distribution patterns of Ag and Se in a thin section of the liver of the Franciscana dolphin were the same; this also implied that Ag was associated with Se in the liver. Thus, the interaction of Ag with Se or S may offer significant protection against the toxicity of Ag in marine mammals. The formation of either Ag(2)Se or Ag(2)S might depend on the Hg levels in the liver. Ag(2)Se was observed in liver samples with relatively high Ag/Hg ratio, whereas liver samples with low Ag/Hg ratio contained Ag(2)S. PMID:21491037

Nakazawa, Emiko; Ikemoto, Tokutaka; Hokura, Akiko; Terada, Yasuko; Kunito, Takashi; Yamamoto, Takahito; Yamada, Tadasu K; Rosas, Fernando C W; Fillmann, Gilberto; Tanabe, Shinsuke; Nakai, Izumi

2011-04-14

440

[Analysis and characterization of Belamcanda chinensis with space mutagenesis breeding by X-ray fluorescence analysis and X-ray diffraction].  

PubMed

The contents of various elements in the fourth generation Belamcanda chinensis (L.) DC. with space mutagenesis breeding were analyzed and characterized. X-ray fluorescence spectrum analysis (XRF) and powder X-ray diffraction (PXRD) were applied jointly. It was found that the content of K element in the space flight mutagenesis increases 1.03 and 0.31 times, Mg enhances 1.44 and 0.06 times, but Al reduces 38.5% and 85.5% respectively compared to the contents in the ground group and the comparison group, while those of Ca, Mn and Fe enhance 0.95, 0.30 and 0.29 times respectively contrasted to the ground group. Besides, there was discovered the crystal of whewellite in the Belamcanda chinensis (L.) DC. and the content in the ground group is less than that of the outer space and the outer space group, which in turn is less than that of the comparison group. It is concluded that the contents of mineral elements indispensable to body in the space group are closer or superior to the comparison, group as compared to the ground group. In the present paper, a quick and simple appraising method is offered, which may be of great significance to the popularization of the planting outer space Chinese traditional medicine to filtrate more excellent breed and set up norm of quality appraisal. PMID:18479047

Guan, Ying; Ding, Xi-Feng; Wang, Wen-Jing; Guo, Xi-Hua; Zhu, Yan-Ying

2008-02-01

441

Interpretation of some X-ray and XUV absorption experiments using SCO  

Microsoft Academic Search

We review some X-ray and XUV absorption experiments on aluminium and germanium making systematic comparison between theory and experiment with the help of the superconfiguration code SCO. The objective is to identify areas that require further theoretical development. As for the low and medium Z elements considered, the statistical term treatment essential in the superconfiguration method is less physically sound

P. Arnault; T. Blenski; G. Dejonghe

2007-01-01

442

Modeling and experiments of x-ray ablation of National Ignition Facility first wall materials  

SciTech Connect

This paper discusses results of modeling and experiments on the x-ray response of selected materials relevant to NIF target chamber design. X-ray energy deposition occurs in such small characteristic depths (on the order of a micron) that thermal conduction and hydrodynamic motion significantly affect the material response, even during the typical 10-ns pulses. The finite-difference ablation model integrates four separate processes: x-ray energy deposition, heat conduction, hydrodynamics, and surface vaporization. Experiments have been conducted at the Nova laser facility in Livermore on response of various materials to NIF-relevant x-ray fluences. Fused silica, Si nitride, B carbide, B, Si carbide, C, Al2O3, and Al were tested. Response was diagnosed using post-shot examinations of the surfaces with SEM and atomic force microscopes. Judgements were made about the dominant removal mechanisms for each material; relative importances of these processes were also studied with the x-ray response model.

Anderson, A.T.; Burnham, A.K.; Tobin, M.T. [Lawrence Livermore National Lab., CA (United States); Peterson, P.F. [California Univ., Berkeley, CA (United States)

1996-06-04

443

Improved micro x-ray fluorescence spectrometer for light element analysis  

SciTech Connect

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 {mu}m Cu wire which resulted in a full width at half maximum of 31 {mu}m for Mo K{alpha} line (17.44 keV) and 44 {mu}m effective beam size for the Cu K edge and 71 {mu}m effective beam size for the Cu L edge. Lower limits of detection in the picogram range for each spot (or {mu}g/cm{sup 2}) 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.

Smolek, Stephan; Streli, Christina; Zoeger, Norbert; Wobrauschek, Peter [Atominstitut, Vienna University of Technology, Stadionallee 2, 1020 Vienna (Austria)

2010-05-15

444

Improved micro x-ray fluorescence spectrometer for light element analysis.  

PubMed

Since most available micro x-ray fluorescence (micro-XRF) spectrometers operate in air, which does not allow the analysis of low-Z elements (Z or = 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 microm Cu wire which resulted in a full width at half maximum of 31 microm for Mo Kalpha line (17.44 keV) and 44 microm effective beam size for the Cu K edge and 71 microm effective beam size for the Cu L edge. Lower limits of detection in the picogram range for each spot (or microg/cm(2)) 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. PMID:20515145

Smolek, Stephan; Streli, Christina; Zoeger, Norbert; Wobrauschek, Peter

2010-05-01

445

Trace element analyses of spheres from the melt zone of the Greenland ice cap using synchrotron X ray fluorescence  

Microsoft Academic Search

Synchrotron X ray fluorescence spectra of unpolished iron and chondritic spheres extracted from sediments collected on the melt zone of the Greenland ice cap allow the analysis of Ni, Cu, Zn, Ga, Ge, Pb, and Se with minimum detection limits on the order of several parts per million. All detected elements are depleted relative to chondritic abundance with the exception

P. Chevallier; C. Jehanno; M. Maurette; S. R. Sutton

1987-01-01

446

Determination of Trace Elements by Thin-Film X-Ray Fluorescence Spectrometry, and Its Application to Zirconium.  

National Technical Information Service (NTIS)

The trace elements are separated from their matrix by precipitation and are collected in concentrated form on a thin film, which is measured by x-ray fluorescence analysis. The technique can be used for the simultaneous determination of many elements, and...

A. M. E. Balaes C. E. Austen

1977-01-01