Note: This page contains sample records for the topic x-ray fluorescence atomic from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

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

2

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

3

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

4

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

5

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

6

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

7

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

8

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

9

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

10

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

11

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

12

A review, bibliography, and tabulation of K, L, and Higher atomic shell x-ray fluorescence yields  

SciTech Connect

The measured K, L, and higher atomic shell x-ray fluorescence yield data, covering the period of 1978 to 1993, following the major previous compilations by Bambynek et al. (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 {omega}{sub K}, {bar {omega}}{sub M}, based on measurements, and on theoretical models, are presented. Values of {omega}{sub K}, {bar {omega}}{sub L}, and {bar {omega}}{sub M}, fitted to standard empirical parametric formulations, are presented. In addition, selected well-characterized measured {omega}{sub K}, {bar {omega}}{sub L} and {bar {omega}}{sub M} results restricted to the period 1978-1993 are listed. These selected measured values are fitted by least squares to polynomials in Z of the form {Sigma}{sub n}a{sub n}Z{sup n} and compared with theoretical and with earlier fitted values. A section on application of fluorescence yield data to computations of x-ray energy-absorption coefficients is included.

Hubbell, J.H. [National Institute of Standards and Technology, Gaithersburgh, MD (United States); Trehan, P.N.; Singh, N.; Chand, B.; Garg, M.L.; Garg, R.R.; Singh, S.; Puri, S. [Panjab Univ., Chandigarh (India); Mehta, D. [Univ. of Delhi (India)

1994-03-01

13

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

14

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

PubMed Central

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

Korecki, P.; Tolkiehn, M.; Dabrowski, K. M.; Novikov, D. V.

2011-01-01

15

Wavelet analysis of white beam x-ray fluorescence holograms: determination of lattice sites and imaging of local atomic structure  

NASA Astrophysics Data System (ADS)

The prospects of atomic structure imaging with the continuous spherical wavelet transform (CSWT) as applied to white beam x-ray fluorescence holograms (XFH) are discussed. Recording of XFH with a white x-ray beam eliminates holographic twin images and minimizes extinction effects. However, the lack of these parasitic effects is accompanied by a limited radial resolution. In this work, by introducing an approximation of the white x-ray spectrum based on the Gumbel distribution, we propose an improvement both in generation of white beam XFH and in data analysis. Using approximate analytical models and realistic numerical simulations, we give a detailed description of the properties and resolution of local structure projections directly obtained from XFH by using wavelet analysis. It is demonstrated that the CSWT and, in particular, its windowed inversion can be effectively used to enhance and speed up reliability factor (R-factor) analysis of the data, which enables precise fully three-dimensional localization of multiple lattice sites of dopants. For this, an exact analytic formula for the inversion is given, enabling its fast calculation in a single step. As an example system, we consider magnetic ions in wurtzite GaN.

Dul, D. T.; Korecki, P.

2012-11-01

16

The interaction between atoms of Au and Cu with clean Si(111) surface: a study combining synchrotron radiation grazing incidence X-ray fluorescence analysis and theoretical calculations.  

PubMed

In order to evaluate the interactions between Au/Cu atoms and clean Si(111) surface, we used synchrotron radiation grazing incidence X-ray fluorescence analysis and theoretical calculations. Optimized geometries and energies on different adsorption sites indicate that the binding energies at different adsorption sites are high, suggesting a strong interaction between metal atom and silicon surface. The Au atom showed higher interaction than Cu atom. The theoretical and experimental data showed good agreement. PMID:19592296

de Carvalho, Hudson W P; Batista, Ana P L; Ramalho, Teodorico C; Pérez, Carlos A; Gobbi, Angelo Luiz

2009-06-16

17

Nondestructive Characterization of Atomic Profiles in Layer-Structured Photovoltaic Materials Using the Method of Angular Dependence of X-Ray Fluorescence (ADXRF)  

SciTech Connect

Angular dependence of x-ray fluorescence technique has been applied to the study of atomic density profile in composite systems. This method is shown to be useful for probing the microstructures and intermixing of constituent elements in layer-structured photovoltaic materials.

Kim, S.; Soo, Y. L.; Kioseoglou, G.; Huang, S.; Kao, Y. H.; Ramanathan, K.; Deb, S.

2000-01-01

18

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

19

A new atomic database for X-ray spectroscopic calculations  

Microsoft Academic Search

The authors undertook to compile a database of recent values of the atomic parameters required for fundamental parameters (FP) calculation of X-ray fluorescence (XRF) spectra, calculation of X-ray absorption in crystals and other samples, and correction of X-ray absorption spectra for self-absorption effects. All values were obtained from published sources and include the elements hydrogen (atomic number 1) through californium

W. T. Elam; B. D. Ravel; J. R. Sieber

2002-01-01

20

New Homogeneous Standards by Atomic Layer Deposition for Synchrotron X-ray Fluorescence and Absorption Spectroscopies  

Microsoft Academic Search

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

A. L. Butterworth; N. Becker; Z. Gainsforth; A. Lanzirotti; M. Newville; T. Proslier; J. Stodolna; S. Sutton; T. Tyliszczak; A. J. Westphal; J. Zasadzinski

2012-01-01

21

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

22

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

23

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

24

X-Ray Holography with Atomic Resolution  

NASA Astrophysics Data System (ADS)

In the conventional diffraction experiments only the intensity of the scattered radiation is recorded, its phase is lost. In holography [1], the scattered radiation is mixed with a reference wave and the resulting interference pattern is recorded. The hologram contains both the intensity and the phase information and the three dimensional image of the object can be reconstructed. The most important limitation of this imaging technique is the spatial resolution, which is given by the wavelength and/or by the source size. In the last decade the introduction of soft x-ray instead of visible light tremendously improved the resolution which reached a few hundred angstrom [2]. An other line in holography, based on the inside source concept, was suggested recently [3]. We have applied this concept for the case of fluorescent x-rays emitted by a single crystal. We were the first to demonstrate theoretically [4] and experimentally [5] the feasibility of x-ray holography with atomic resolution. We have recorded the holograms of different crystals and successfully reconstructed the three dimensional order of the atoms. [1] D. Gabor, Nature 161, 777 (1948). [2] M. Howels, C. Jacobsen, J. Kirz, R. Feder, K. McQuaid and S. Rothman, Science 238, 514 (1987). [3] A. Szöke, in Short Wavelength Coherent Radiation: Generation and Applications, T. Attwood, J. Booker (eds), AIP Conference Proceedings No. 147, New York (1986). [4] M. Tegze and G. Faigel, Europhys. Lett. 16, 41 (1991). [5] M. Tegze and G. Faigel, Nature 380, 49 (1996).

Tegze, Miklós

1997-03-01

25

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

26

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

Microsoft Academic Search

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

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

2004-01-01

27

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

28

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

29

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

SciTech Connect

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

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

2011-12-31

30

Resonant inelastic x-ray scattering from molecules and atoms  

SciTech Connect

X-ray fluorescence spectroscopy is one of the most powerful methods for the understanding of the electronic structure of matter. We report here on fluorescence experiments in the 2 to 6 keV photon energy range using tunable synchrotron radiation and the resulting experimental programs on resonant inelastic scattering in atoms and on polarization measurements in resonant molecular excitations.

Arp, U.; Deslattes, R.D. [National Institute of Standards and Technology, Gaithersburg, MD (United States); Miyano, K.E. [Brooklyn College, Brooklyn, NY (United States); Southworth, S.H. [and others

1995-12-31

31

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

32

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

33

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

34

Nondestructive Characterization of Atomic Density Profile in CdS/Zn2SnO4 Junctions by X-Ray Fluorescence: Preprint  

SciTech Connect

Presented at the 2001 NCPV Program Review Meeting: Atomic density profile of selected atomic species in a series of CdS/Zn{sub 2}SnO{sub 4} junctions has been investigated by using the method of Angular Dependence of X-ray Fluorescence (ADXRF). Samples of CdS, Zn{sub 2}SnO{sub 4} (ZTO), and CdS/ZTO junctions were grown on glass, followed by different annealing processes. Special attention is directed to a comparison of samples heat-treated in argon and in CdCl{sub 2} at different temperatures. It has been found that different heat treatment conditions can result in drastic variations in the density distribution of the constituents in the system.

Kim, S.; Soo, Y.L.; Kioseoglou, G.; Kao, Y.H.; Wu, X.

2001-10-01

35

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

36

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

37

X-Ray Deficiency in Mesonic Atoms  

Microsoft Academic Search

We present an analysis of pi-mesonic atoms, based upon cascade calculations taking into account the known processes of radiation, Auger transitions, and nuclear absorption. This analysis, together with the previous one on mu-mesonic atoms, is intended to provide a deeper insight into the unsolved problem of the deficiency of x rays in mesonic atoms. It is shown that the pi-mesonic

Y. Eisenberg; D. Kessler

1961-01-01

38

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

39

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

40

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

41

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

42

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

43

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

44

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.

45

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

46

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

47

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

48

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

49

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

50

In Situ X-Ray Fluorescence Measurements During Atomic Layer Deposition: Nucleation and Growth of TiO2 on Planar Substrates and in Nanoporous Films  

SciTech Connect

Synchrotron-based X-ray fluorescence (XRF) is introduced as a promising in situ technique to monitor atomic layer deposition cycle-per-cycle. It is shown that the technique is greatly suitable to study initial nucleation on planar substrates. The initial growth of TiO{sub 2} from tetrakis(dimethylamino)titanium (TDMAT) and H{sub 2}O is found to be linear on thermally grown SiO{sub 2}, substrate-inhibited on H-terminated Si and substrateenhanced on atomic layer deposited Al{sub 2}O{sub 3}. Furthermore, in situ XRF is employed to monitor the Ti uptake during deposition of TiO{sub 2} in nanoporous silica films. In mesoporous films, the Ti content varied quadratically with the number of cycles, a behavior that is attributed to a decreasing surface area with progressing deposition. In microporous films, the XRF data suggest that 1-3 ALD cycles shrunk the pore diameters below the kinetic diameter of the TDMAT molecule.

J Dendooven; S Sree; K DeKeyser; D Deduytsche; J Martens; K Ludwig; C Detavernier

2011-12-31

51

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

52

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

53

Element sensitive holographic imaging of atomic structures using white x rays  

NASA Astrophysics Data System (ADS)

White-beam x-ray fluorescence holograms were recorded using a 50 watt x-ray tube for a Cu3Au single crystal. Element sensitivity for this model sample was explicitly demonstrated by measuring distinct holograms using Cu K and Au L x-ray fluorescence. The phase sensitivity of the recorded holograms enabled us to obtain projections of the local atomic structure and image the electron density within the unit cell, relative to either Au or Cu atoms. Since the experimental setup does not require any optics and the angular resolution requirements are loose, the application of more powerful laboratory x-ray sources is straightforward.

D?browski, K. M.; Dul, D. T.; Roszczynialski, T. P.; Korecki, P.

2013-02-01

54

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

55

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

56

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

57

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...

58

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

59

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

60

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

61

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

62

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

63

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

64

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

NASA Astrophysics Data System (ADS)

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

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

2004-12-01

65

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

66

Resonant x-ray Raman scattering from atoms and molecules  

SciTech Connect

Inelastic x-ray scattering and elastic x-ray scattering are fundamentally related processes. When the x-ray photon energy is near the ionization threshold for an inner shell, the inelastic channel is dominated by resonant x-ray Raman scattering. Studies of this emission not only illuminate the resonant scattering process in general, they also point to new opportunities for spectral studies of electronic structure using x-rays. Atoms in the form of a free gas provide an ideal target for testing the current theoretical understanding of resonant x-ray Raman scattering. In addition, x-ray scattering from molecular gases demonstrates the effect of bonding symmetry on the polarization and angular distribution of the scattered x-rays. Comparisons of experimental data with theory demonstrate both the successes and limitations of simple, single-electron interpretations of the scattering process.

Cowan, P.L.

1992-01-01

67

Resonant x-ray Raman scattering from atoms and molecules  

SciTech Connect

Inelastic x-ray scattering and elastic x-ray scattering are fundamentally related processes. When the x-ray photon energy is near the ionization threshold for an inner shell, the inelastic channel is dominated by resonant x-ray Raman scattering. Studies of this emission not only illuminate the resonant scattering process in general, they also point to new opportunities for spectral studies of electronic structure using x-rays. Atoms in the form of a free gas provide an ideal target for testing the current theoretical understanding of resonant x-ray Raman scattering. In addition, x-ray scattering from molecular gases demonstrates the effect of bonding symmetry on the polarization and angular distribution of the scattered x-rays. Comparisons of experimental data with theory demonstrate both the successes and limitations of simple, single-electron interpretations of the scattering process.

Cowan, P.L.

1992-12-31

68

[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

69

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

70

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

71

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

72

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

73

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

74

Studies of X-Rays from Mu-Mesonic Atoms  

Microsoft Academic Search

A new technique of x-ray spectroscopy of mu-mesonic atoms has been developed. The x-rays are produced when a mu- meson undergoes transitions between Bohr orbits about nuclei of various Z. The mesons are produced by the Columbia University 164-in. Nevis cyclotron. The x-rays are detected, and their energies are measured to better than 1 percent accuracy (for Z>=22) using a

Val L. Fitch; James Rainwater

1953-01-01

75

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

76

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

77

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

78

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

79

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

80

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

81

Atomic Force Microscopy, Electron Paramagnetic Resonance and X-ray Fluorescence Investigations of Self-Assembled Lines from Colloidal Solutions of Lamella MnOx  

SciTech Connect

In this article, we report AFM, EPR, and X-ray fluorescence studies of well-ordered linear patterns of manganese oxide deposited onto glass and quartz surfaces. The patterns reported here were generated from newly described colloidal solutions of manganese oxide nanoparticles of composition [N(CH{sub 3}){sub 4}]{sup +}{sub 0.93}Mn{sup 4+}{sub 2.1}Mn{sup 3+}{sub 1.9}O{sub 7}(OH){sub 1.03} {center_dot} 5H{sub 2}O. Qualitative studies, and quantitative analysis of the concentration dependence of the width, frequency, and height of the ordered lines of MnO{sub x} (average Mn oxidation state of 3.52) were performed. These results provide information about the morphology of the patterns, the distribution of Mn within the lines, and the nature of free-radicals detected in this material.

Marquez, M.; Robinson, Josh; Nostrand, V.Van; Schaefer, D.; Ryzhkov, L.R.; Lowe, Walter; Suib, S.L. (Towson); (Howard); (Connecticut); (LANL)

2009-04-22

82

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

83

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

84

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

85

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

86

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

87

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

88

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

89

Atomic diffusion studied with coherent X-rays.  

PubMed

Knowledge of atomic diffusion is a fundamental issue in synthesis and stability of materials. Direct studies of the elementary diffusion event, that is, how the individual atoms 'jump', are scarce, as the available techniques are limited to selected systems. Here we show how by monitoring the spatial and temporal variations of the scattered coherent X-ray intensity the diffusion of single atoms can be studied. This is demonstrated for the intermetallic alloy Cu(90)Au(10). By measuring along several directions in reciprocal space, we can elucidate the dynamical behaviour of single atoms as a function of their neighbourhood. This method, usually referred to as X-ray photon correlation spectroscopy (XPCS), does not rely on specific atomic species or isotopes and can thus be applied to almost any system. Thus, given the advent of the next-generation X-ray sources, XPCS has the potential to become the main method for quantitatively understanding diffusion on the atomic scale. PMID:19633660

Leitner, Michael; Sepiol, Bogdan; Stadler, Lorenz-Mathias; Pfau, Bastian; Vogl, Gero

2009-07-26

90

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

91

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

92

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

93

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

94

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

95

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

96

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

97

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

98

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

99

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

100

X-ray-photon scattering by an excited atom  

NASA Astrophysics Data System (ADS)

The existence of resonances in a double differential cross section of anomalous inelastic scattering of an x-ray photon by an excited atom at the attosecond time scale of the photon-electron contact interaction is theoretically predicted. These resonances realize unusual types of the excited atom vacancy decay channels. The subject of investigation is the atom of Be, excited to a discrete spectrum state via the 1s?np, n?2 channel. Experimental realization of the theoretically predicted quantum effect may provide a new method for increasing the energy of photons generated by an x-ray free electron laser.

Hopersky, Alexey N.; Nadolinsky, Alexey M.; Novikov, Sergey A.

2013-09-01

101

Atomic diffusion studied with coherent X-rays  

Microsoft Academic Search

Knowledge of atomic diffusion is a fundamental issue in synthesis and stability of materials. Direct studies of the elementary diffusion event, that is, how the individual atoms `jump', are scarce, as the available techniques are limited to selected systems. Here we show how by monitoring the spatial and temporal variations of the scattered coherent X-ray intensity the diffusion of single

Michael Leitner; Bogdan Sepiol; Lorenz-Mathias Stadler; Bastian Pfau; Gero Vogl

2009-01-01

102

Moseley's Work on X-Rays and Atomic Number  

Microsoft Academic Search

This article focuses on an interesting topic, the origins of Moseley's conclusion that there was a whole number relationship in the frequencies of X-rays emitted from atoms after electron bombardment, i.e., the discovery of atomic numbers. It brings forth valid questions such as, 1) when does insight influence the analysis of data and 2) how does the accuracy of data

C. W. Haigh

1995-01-01

103

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

104

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.

105

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

106

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

107

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

108

Atomic Data Needs for X-ray Astronomy  

NASA Astrophysics Data System (ADS)

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

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

2000-10-01

109

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

110

X-ray-absorption fine structure in embedded atoms  

Microsoft Academic Search

Oscillatory structure is found in the atomic background absorption in x-ray-absorption fine-structure (XAFS) measurements. This atomic XAFS (AXAFS) arises from scattering within an embedded atom, and is analogous to the Ramsauer-Townsend effect. Calculations and measurements confirm the existence of AXAFS and show that it can dominate contributions such as multielectron excitations. The structure is sensitive to chemical effects and thus

J. J. Rehr; C. H. Booth; F. Bridges; S. I. Zabinsky

1994-01-01

111

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

112

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

113

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

114

Single atom identification by energy dispersive x-ray spectroscopy  

SciTech Connect

Using aberration-corrected scanning transmission electron microscope and energy dispersive x-ray spectroscopy, single, isolated impurity atoms of silicon and platinum in monolayer and multilayer graphene are identified. Simultaneously acquired electron energy loss spectra confirm the elemental identification. Contamination difficulties are overcome by employing near-UHV sample conditions. Signal intensities agree within a factor of two with standardless estimates.

Lovejoy, T. C.; Dellby, N.; Krivanek, O. L. [Nion, 1102 8th St., Kirkland, Washington 98033 (United States); Ramasse, Q. M. [SuperSTEM Laboratory, STFC Daresbury, Keckwick Lane, Daresbury WA4 4AD (United Kingdom); Falke, M.; Kaeppel, A.; Terborg, R. [Bruker Nano GmbH, Schwarzschildstr. 12, 12489 Berlin (Germany); Zan, R. [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom)

2012-04-09

115

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

116

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

117

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

118

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

119

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

120

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

121

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

122

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

123

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

124

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

125

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

126

Program RELAX: A code designed to calculate atomic relaxation spectra of x-rays and electrons  

SciTech Connect

The code RELAX is designed to calculate atomic relaxation spectra of X-rays and electrons due to bound-bound transitions. This calculation is based on the atomic transition data contained in the Livermore Evaluated Atomic Data Library (EADL). The results produced by this code for fluorescence yield vs. atomic number (Z) have been published in Tables and Graphs of Atomic Subshell and Relaxation Data Derived from the LLNL Evaluated Atomic Data Library (EADL), z = 1--100{double prime}, UCRL-50400, Vol. 30, October 31, 1991, Lawrence Livermore National Laboratory.

Cullen, D.E.

1992-03-20

127

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

128

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

129

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

130

Atomic holography with electrons and x-rays: Theoretical and experimental studies  

SciTech Connect

Gabor first proposed holography in 1948 as a means to experimentally record the amplitude and phase of scattered wavefronts, relative to a direct unscattered wave, and to use such a {open_quotes}hologram{close_quotes} to directly image atomic structure. But imaging at atomic resolution has not yet been possible in the way he proposed. Much more recently, Szoeke in 1986 noted that photoexcited atoms can emit photoelectron of fluorescent x-ray wavefronts that are scattered by neighboring atoms, thus yielding the direct and scattered wavefronts as detected in the far field that can then be interpreted as holographic in nature. By now, several algorithms for directly reconstructing three-dimensional atomic images from electron holograms have been proposed (e.g. by Barton) and successfully tested against experiment and theory. Very recently, Tegze and Faigel, and Grog et al. have recorded experimental x-ray fluorescence holograms, and these are found to yield atomic images that are more free of the kinds of aberrations caused by the non-ideal emission or scattering of electrons. The basic principles of these holographic atomic imaging methods are reviewed, including illustrative applications of the reconstruction algorithms to both theoretical and experimental electron and x-ray holograms. The author also discusses the prospects and limitations of these newly emerging atomic structural probes.

Len, P.M. [Univ. of California, Davis, CA (United States). Dept. of Physics]|[Lawrence Berkeley National Lab., CA (United States)

1997-06-01

131

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

132

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

133

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

134

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

135

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

136

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

137

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

138

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

139

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

140

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

141

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

142

Atomic inner-shell x-ray laser pumped by an x-ray free-electron laser  

SciTech Connect

We discuss possibilities of pumping an atomic inner-shell x-ray laser with an x-ray free-electron laser (XFEL). Self-consistent gain calculations show that with the first available XFEL, the Linac Coherent Light Source at Stanford, it will become possible to produce subfemtosecond x-ray pulses at intensities reaching 6x10{sup 16} W/cm{sup 2}. Small-signal gain calculations indicate that saturation of more than one lasing line is possible, resulting in temporally separated femtosecond x-ray pulses of different wavelengths. The presented lasing scheme creates broad capability for advancing the field of high-intensity ultrashort x-ray physics.

Rohringer, Nina; London, Richard [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

2009-07-15

143

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

144

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

145

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

146

Nonlinear Atomic Response to Intense Ultrashort X Rays  

SciTech Connect

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

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

2011-02-25

147

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

148

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

SciTech Connect

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

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

2009-04-02

149

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

NASA Astrophysics Data System (ADS)

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

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

2009-02-01

150

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

151

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

152

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

153

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

154

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

155

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

156

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

157

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

158

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

159

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

160

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

161

Atomic Physics Using Ultra-Intense X-Ray Pulses  

NASA Astrophysics Data System (ADS)

The combination of short wavelengths and ultrahigh intensities as provided by the new soft and hard X-ray free electron laser sources opens the doorway to totally new experiments on photon-matter interaction. It concerns, in particular, new classes of nonlinear inner-atomic processes. In the present contribution, recent results on sequential and nonsequential multi-photon ionization of gas phase targets are presented and discussed; including processes where also inner shells are affected. Moreover, examples are given how linear and nonlinear photoionization may be used for online photon diagnostics at these new radiation sources.

Martins, M.; Meyer, M.; Richter, M.; Sorokin, A. A.; Tiedtke, K.

162

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

163

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

164

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

165

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

166

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

167

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

168

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

169

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

170

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

171

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

172

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

173

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

174

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

175

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

176

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

177

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

178

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

179

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

180

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

181

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

182

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

183

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

184

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

185

X-ray emission in relativistic ion-atom collisions  

SciTech Connect

X-ray line-emission produced during collisions of relativistic multi-charged ions with atoms is discussed. A direct calculation for radiative electron capture (REC) rates is presented within the distorted-wave impulse approximation (DWIA). Simple formulae are obtained for the angular distribution of radiation, and closed analytic formula are derived for small {alpha}Z. Reasonable agreement with recent experiments is found for photoemission rates and angular distributions. Our results indicate that the photon spectrum is rather insensitive to target structure, but dependent on multiple-scattering corrections, and this contradicts other theoretical predictions. However, in asymmetric collisions our results are in broad agreement with experiment and Relativistic Impulse Approximation (RIA) calculations. Magnetic transitions are also analysed in terms of the electron and photon polarization correlation parameters.

McCann, J. F.; Glass, J. T.; Crothers, D. S. F. [Physics Department, The University, Durham DH1 3LE (United Kingdom); Institut fuer Theoretische Physik der Justus-Liebig-Universitaet, 39392 Giessen (Germany); Theoretical and Computational Physics Research Division, Queen's University of Belfast, Belfast BT7 1NN, Northern Ireland (United Kingdom); Theoretical and Computational Physics Research Division, Queen's University of Belfast, Belfast BT7 1NN, Northern Ireland (United Kingdom)

1996-02-25

186

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

187

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

188

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

189

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

190

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

191

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

192

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

193

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

194

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

195

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

Microsoft Academic Search

We demonstrate that ultralow-level Al impurities on a silicon surface can be measured by using the high-resolution grazing emission x-ray fluorescence (GEXRF) technique combined with synchrotron-radiation excitation. An Al-impurity level of about 10š˛ atoms\\/cm˛ was reached by observing the Al K x-ray fluorescence in the resonant Raman-scattering background-''free'' regime by choosing an appropriate beam energy below the Si K absorption

A. Kubala-Kukus; D. Banas; M. Pajek; W. Cao; J.-Cl. Dousse; J. Hoszowska; Y. Kayser; M. Szlachetko; M. Salome; J. Susini; J. Szlachetko

2009-01-01

196

Site-specific distribution of copper, selenium, and zinc in human kidney by synchrotron radiation induced X-ray fluorescence  

NASA Astrophysics Data System (ADS)

Distribution of trace elements such as Cu, Se, and Zn in human kidney was examined by use of nondestructive synchrotron radiation X-ray fluorescence (SR-XRF) imaging technique. All elements measured were more accumulated in the renal cortex than in the medulla. The renal Cu and Zn distributions obtained by SR-XRF imaging were consistent with those obtained by inductively coupled plasma atomic emission spectrometry (ICP-AES). Furthermore, correlation analysis based on the X-ray intensity data of each analytical point showed a positive correlation of the distribution of these elements.

Homma, S.; Nakai, I.; Misawa, S.; Shimojo, N.

1995-10-01

197

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

198

Atomic photoionization with synchronized X-ray and optical lasers  

NASA Astrophysics Data System (ADS)

Photoionization is the dominant processes after the interaction of atoms with photons of short wavelength. New possibilities to obtain dynamical information about this extremely fast process were opened up in the last years due to the development of Free Electron Lasers, such as FLASH in Hamburg and LCLS in Stanford, with their unprecedented characteristics, especially the ultra-short temporal width of the pulses, which can be as short of a few femtoseconds, and the extremely high number of photons per pulse (about 10^12-10^13 photons/pulse) [1,2]. In a series of experiments at FLASH, the combination of XUV FEL radiation and synchronized NIR laser pulses was used to study the Above Threshold Ionization (ATI) in rare gases for the first time in a regime free from unwanted interference effects. Especially, the polarization dependence of the sideband structures in the electron spectra yields detailed insights into the photoionization dynamics, in particular into the distribution of angular momenta for the outgoing electrons [3]. Recent experiments at the LCLS have taken advantage of the very short (2-5fs) pulse durations, which are delivered by this new X-ray Free Electron Laser. This temporal width coincides with the lifetime of core hole states governing the dynamics of the Auger decay, and with the temporal width of one cycle of the electric field in the optical wavelength regime. By applying angle-resolved electron spectroscopy, the KLL Auger decay in atomic Ne was studied after excitation with few-fs X-ray (1 keV) pulses in the presence of an optical (800 nm) dressing field. The experimental spectra are marked by strong interference effects caused by the coherent emission of electrons produced during one cycle of the superimposed optical dressing field, in excellent agreement with recent theoretical work.[4pt] [1] C. Bostedt et al., Nucl. Instrum. Meth. A 601, 108 (2009).[0pt] [2] N. Berrah et al., J. Mod. Opt. 52, 1015 (2010).[0pt] [3] M. Meyer et al., Phys. Rev. Lett. 101, 193002 (2008).[0pt] [4] Y. Ding et al., Phys. Rev. Lett. 102, 254801 (2009).[0pt] [5] A.K. Kazansky, N.M. Kabachnik, J.Phys.B 42, 121002 (2009); 43, 035601 (2010).

Meyer, Michael

2011-06-01

199

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

200

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

201

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

202

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

203

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

204

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

205

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

206

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

207

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

208

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

209

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

210

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

211

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

212

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

213

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

NASA Astrophysics Data System (ADS)

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

Hoshino, Masato; Ishino, Toyoaki; Namiki, Takashi; Yamada, Norimitsu; Watanabe, Norio; Aoki, Sadao

2007-07-01

214

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

PubMed

A full-field x-ray fluorescence imaging microscope using a Wolter mirror was constructed at Photon Factory BL3C2. White x rays from a bending magnet were used to excite x-ray fluorescence and to enhance the x-ray fluorescence intensity. A photon-counting method using a charge-coupled device was applied to obtain an x-ray fluorescence spectrum at the image plane. The spatial distributions of some specific atoms such as Fe and Zn were obtained from photon-counting calculations. An energy resolution of 220 eV at the Fe Kalpha line was obtained from the x-ray fluorescence spectrum by the photon-counting method. The newly developed three-dimensional element mappings of the specific atoms were accomplished by the photon-counting method and a reconstruction technique using computed tomography. PMID:17672765

Hoshino, Masato; Ishino, Toyoaki; Namiki, Takashi; Yamada, Norimitsu; Watanabe, Norio; Aoki, Sadao

2007-07-01

215

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

NASA Astrophysics Data System (ADS)

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

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

2008-03-01

216

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

217

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

218

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

219

Atomic-Scale Studies of Oxides Supported Catalysts by X-ray and Imaging Methods  

NASA Astrophysics Data System (ADS)

Oxide supported metal and metal oxide catalysts have been synthesized by molecular beam epitaxy (MBE) and atomic-layer deposition (ALD). To obtain a general idea of how a catalyst behaves chemically and structurally during reduction-oxidization (redox) reaction at atomic-scale, oxide single crystals with well-defined surfaces are used as supports to grow monolayer (ML) and sub-ML catalysts. Several model catalysis systems are investigated: Pt/SrTiO 3(001), WOX/alpha-Fe2O3(0001), VO X/alpha-TiO2(110) and mixed VOX/WOX/alpha-TiO 2(110). For purposes of comparison the catalysts include a noble metal (Pt), inert oxide (WOX) and active oxide (VOX). The oxide supports are categorized as a reducible substrate, alpha-Fe2 O3(0001), and non-reducible substrates, alpha-TiO 2(110) and SrTiO3(001). To obtain in situ information, a variety of X-ray and scanning imaging methods have been applied together to study the atomic-scale surface morphology, structure and cation dynamics during chemical reactions. These characterization techniques are: X-ray standing wave (XSW), grazing-incident small angle X-ray scattering (GISAXS), X-ray absorption fine structure (XAFS), X-ray reflectivity (XRR), X-ray fluorescence (XRF), X-ray photoelectron spectroscopy (XPS), atomic-force microscopy (AFM) and scanning electron microscopy (SEM). Our studies show that different combinations of catalysts and substrates give distinct structural and chemical state changes in redox reactions. For MBE deposited sub-monolayer (sub-ML) Pt on the 2 x 1 SrTiO 3(001) surface, AFM shows the formation of nanoparticles and XSW atomic imaging shows that these nanoparticles are composed of Pt face-centered-cubic nanocrystals with cube-on-cube epitaxy coherent to the substrate unit cell. Different Pt coverages lead to differences in the observed XSW image of the interfacial structure, which is explained by the Pt-Pt interaction becoming stronger than the Pt-substrate interaction as the coverage is increased from 0.2 to 0.6 ML. For ALD grown Pt on SrTiO3(001) surface, AFM combined with SEM, XRR, reciprocal space mapping and GISAXS together show the dramatic surface morphology changes before and after UHV annealing. These thermally induced structural changes are explained by surface diffusion, and the surface/interface energies for noble metals on oxides. For ALD deposited sub-ML WOX/alpha-Fe2O 3(0001) and VOX/alpha-TiO2(110), redox-induced surface cation dynamics were observed by a combination of in situ XSW, ex situ XPS and AFM. Direct atomic-scale images created from XSW show how W or V cation responds to redox reactions, which are further compared and explained with density functional theory calculations. Extended work on mixed catalysts VOX/WOX/alpha-TiO2(110) demonstrates that a synergistic effort is developed when a proper amount of WOX is mixed with VOX. This effect is further explained by the W-introduced surface density of Bronsted acid sites.

Feng, Zhenxing

220

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

221

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

Microsoft Academic Search

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

Stéphanie Cuven; Pierre Francus; Scott F. Lamoureux

2010-01-01

222

Monte Carlo simulation of the backscatter region in photon-excited energy dispersive X-ray fluorescence spectra  

Microsoft Academic Search

The backscatter region of energy-dispersive X-ray fluorescence spectra obtained by a typical radioisotope system is examined\\u000a in detail. A Monte Carlo simulation program which incorporates all the information on photon scattering processes including\\u000a electron momentum distributions in target atoms, form factors and scattering factors for the cross-sections is presented.\\u000a The program uses extensive variance reduction techniques and has the option

F. ARINff; R. P. Gardner

1979-01-01

223

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

Microsoft Academic Search

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

Kengo Moribayashi

2008-01-01

224

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

225

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

226

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.

227

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

228

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

229

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

Microsoft Academic Search

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

G. J. Heyes; A. J. Mill

2004-01-01

230

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

231

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

232

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

233

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

234

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

235

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

236

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

237

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

238

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

239

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

240

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

241

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

242

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

243

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

244

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

245

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

SciTech Connect

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

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

2011-09-09

246

COINCIDENCE X-RAY FLUORESCENCE (CXRF) SPECTROMETRY FOR IN VIVO QUANTITATIVE MEASUREMENT OF BONE LEAD  

Microsoft Academic Search

In previous work, the main interfering background for the in vivo lead in bone measurement was found to be from back-scattered Compton and Rayleigh source photons, which is, therefore, also the main problem for the improvement of sensitivity. Based on the physics of atomic transition, certain fractions of the characteristic K-series X-rays and L-series X-rays are in true coincidence. With

Weijun Guo; Robin P. Gardner

247

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

248

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

249

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

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

250

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

251

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

252

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

253

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

254

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

255

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

256

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

257

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

258

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

259

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

260

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

261

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

262

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

NASA Astrophysics Data System (ADS)

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

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

2005-02-01

263

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

SciTech Connect

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

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

2004-03-03

264

In situ synchrotron x-ray characterization of ZnO atomic layer deposition.  

SciTech Connect

The utility of in situ synchrotron x-ray scattering and fluorescence in gaining insight into the early stages of the atomic layer deposition process is demonstrated in this study of ZnO growth on Si. ZnO films are found to initially grow as islands, with the onset of coalescence occurring during the fourth growth cycle. The start of coalescence is accompanied by a small increase in surface roughness. After ten cycles of growth, the growth rate decreases from 4.2 to 3.0 {angstrom} per cycle, with the growth following expected self-limiting behavior. The overall growth process is consistent with the model of Puurunen and Vandervorts for substrate-inhibited growth.

Fong, D. D.; Eastman, J. A.; Kim, S. K.; Fister, T. T.; Highland, M. J.; Baldo, P. M.; Fuoss, P. H.

2010-11-08

265

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

266

Measurements of chemical species in flame at temperatures above 2000°C - X-ray atomic absorption spectroscopy  

NASA Astrophysics Data System (ADS)

XANES spectra of chemical species in high temperature flame were measured for the first time utilizing apparatus of atomic absorption spectroscopy and synchrotron radiation. Metal nitrate solution [1 M] was introduced into an air-acetylene flame (ca. 2000°C) through nebulizer. Small monochromated X-ray beam was passed through the flame so that its XANES spectra were successfully measured in fluorescence mode. XANES spectra of free atoms were detected for the nitrate solutions of Cu and Ni, but not for those of Sr and Rb, which have low ionization potentials and low atomization efficiency and may exist as ionized species such as free ions, oxides, etc. in the flame.

Nakai, Izumi; Terada, Yasuko; Nomura, Masaharu; Uchida, Tetsuo

1995-02-01

267

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

268

Determination of trace elements in bee honey, pollen and tissue by total reflection and radioisotope X-ray fluorescence spectrometry  

NASA Astrophysics Data System (ADS)

Multielemental determinations in samples of various types of bee honey, pollen and bee tissue have been carried out using total reflection X-ray fluorescence spectrometry (TXRF) and radioisotope excited X-ray fluorescence spectrometry (XRF). The objective was to establish whether the elemental content of bee honey, in particular, correlates with any useful information about the environment, variety of honey, etc. An attempt has also been made to determine the X-ray techniques' ability to compete with atomic absorption spectrometry (AAS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES), with regard to elemental sensitivity, accuracy, sample preparation procedures, and in particular, economic performance, which is very important in selecting an appropriate technique for the analysis of large numbers of samples. The results confirm the advantages of the TXRF method for trace element analysis, but only when utilising monochromatic excitation and selecting a proper sample preparation procedure. The radioisotope XRF technique, which does not require any sample preparation, is still very competitive in analysis of elements with concentrations above a few ten ppm. Preliminary results also confirm some correlations between the elemental content of honey and the status of the environment, and encourage further work in this direction

Kump, P.; Ne?emer, M.; Šnajder, J.

1996-04-01

269

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

270

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

271

Iodine X-ray fluorescence computed tomography system utilizing a cadmium telluride detector in conjunction with a cerium-target tube  

NASA Astrophysics Data System (ADS)

An X-ray fluorescence computed tomography system (XRF-CT) is useful for determining the main atoms in objects. To detect iodine atoms without using a synchrotron, we developed an XRF-CT system utilizing a cadmium telluride (CdTe) detector and a cerium X-ray generator. CT is performed by repeated linear scans and rotations of an object. When cerium K-series characteristic X-rays are absorbed by iodine atoms in objects, iodine K fluorescence is produced from atoms and is detected by the CdTe detector. Next, event signals of X-ray photons are produced with the use of charge-sensitive and shaping amplifiers. Iodine K? fluorescence is isolated using a multichannel analyzer, and the number of photons is counted using a counter card. In energy-dispersive XRF-CT, the tube voltage and tube current were 70 kV and 0.40 mA, respectively, and the X-ray intensity was 115.3 ?Gy/s at a distance of 1.0 m from the source. The demonstration of XRF-CT was carried out by the selection of photons in an energy range from 27.5 to 29.5 keV with a photon-energy resolution of 1.2 keV.

Hagiwara, Osahiko; Watanabe, Manabu; Sato, Eiichi; Matsukiyo, Hiroshi; Osawa, Akihiro; Enomoto, Toshiyuki; Nagao, Jiro; Sato, Shigehiro; Ogawa, Akira; Onagawa, Jun

2011-06-01

272

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

273

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

SciTech Connect

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

Falcone, Roger

2008-07-15

274

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

275

Non-destructive analysis of uranium and\\/or plutonium using X-ray (K or L band) fluorescence excited by sealed sources or X-ray tubes  

Microsoft Academic Search

Uranium, plutonium and, more generally, high atomic number elements can be analyzed by excitation of their K or L X-rays by sealed sources or by X-ray tubes. The Radionuclides Application Branch of the CEA Ionizing Radiation Metrology and Applications Department has designed several industrial prototypes for non-destructive analysis of actinides at different nuclear fuel cycle stages in various matrices: e.g.,

J. L. Szabo; A. C. Simon; R. Junca

1994-01-01

276

Refraction and absorption of x rays by laser-dressed atoms.  

SciTech Connect

X-ray refraction and absorption by neon atoms under the influence of an 800 nm laser with an intensity of 10{sup 13} W/cm{sup 2} is investigated. For this purpose, we use an ab initio theory suitable for optical strong-field problems. Its results are interpreted in terms of a three-level model. On the Ne 1s {yields} 3p resonance, we find electromagnetically induced transparency (EIT) for x rays. Our work opens novel perspectives for ultrafast x-ray pulse shaping.

Buth, C.; Santra, R.; Young, L. (Chemical Sciences and Engineering Division)

2010-06-01

277

High contrast x-ray speckle from atomic-scale order in liquids and glasses.  

PubMed

The availability of ultrafast pulses of coherent hard x rays from the Linac Coherent Light Source opens new opportunities for studies of atomic-scale dynamics in amorphous materials. Here, we show that single ultrafast coherent x-ray pulses can be used to observe the speckle contrast in the high-angle diffraction from liquid Ga and glassy Ni(2)Pd(2)P and B(2)O(3). We determine the thresholds above which the x-ray pulses disturb the atomic arrangements. Furthermore, high contrast speckle is observed in scattering patterns from the glasses integrated over many pulses, demonstrating that the source and optics are sufficiently stable for x-ray photon correlation spectroscopy studies of dynamics over a wide range of time scales. PMID:23215295

Hruszkewycz, S O; Sutton, M; Fuoss, P H; Adams, B; Rosenkranz, S; Ludwig, K F; Roseker, W; Fritz, D; Cammarata, M; Zhu, D; Lee, S; Lemke, H; Gutt, C; Robert, A; Grübel, G; Stephenson, G B

2012-11-02

278

High Contrast X-ray Speckle from Atomic-Scale Order in Liquids and Glasses  

NASA Astrophysics Data System (ADS)

The availability of ultrafast pulses of coherent hard x rays from the Linac Coherent Light Source opens new opportunities for studies of atomic-scale dynamics in amorphous materials. Here, we show that single ultrafast coherent x-ray pulses can be used to observe the speckle contrast in the high-angle diffraction from liquid Ga and glassy Ni2Pd2P and B2O3. We determine the thresholds above which the x-ray pulses disturb the atomic arrangements. Furthermore, high contrast speckle is observed in scattering patterns from the glasses integrated over many pulses, demonstrating that the source and optics are sufficiently stable for x-ray photon correlation spectroscopy studies of dynamics over a wide range of time scales.

Hruszkewycz, S. O.; Sutton, M.; Fuoss, P. H.; Adams, B.; Rosenkranz, S.; Ludwig, K. F., Jr.; Roseker, W.; Fritz, D.; Cammarata, M.; Zhu, D.; Lee, S.; Lemke, H.; Gutt, C.; Robert, A.; Grübel, G.; Stephenson, G. B.

2012-11-01

279

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

PubMed Central

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

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

2008-01-01

280

X-ray transition yields of low-Z kaonic atoms produced in Kapton  

NASA Astrophysics Data System (ADS)

The X-ray transition yields of kaonic atoms produced in Kapton polyimide (C22H10N2O5) were measured for the first time in the SIDDHARTA experiment. X-ray yields of the kaonic atoms with low atomic numbers (Z=6,7, and 8) and transitions with high principal quantum numbers (n=5-8) were determined. The relative yields of the successive transitions in the same atoms and the yield ratios of carbon-to-nitrogen (C:N) and carbon-to-oxygen (C:O) for the same transitions were also determined. These X-ray yields provide important information for understanding the capture ratios and cascade mechanisms of kaonic atoms produced in a compound material, such as Kapton.

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

2013-10-01

281

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

282

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

283

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

284

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

285

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

286

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

287

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

288

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

289

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

290

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

291

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

292

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...

293

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

294

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

295

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

296

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

297

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

298

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...

299

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

300

Quantitative measurement of PM10 by means of X-ray fluorescence spectra  

NASA Astrophysics Data System (ADS)

We developed an automatic device able to sample and analyze in situ and in real time airborne particulate matter (PM) using the X-ray fluorescence of the chemical species layered on a filter, having atomic numbers between 19 (Potassium) and 82 (Lead). Furthermore, we developed a calibration technique, which gives the parameters for real time automatic determination of the absolute mass of the chemical species present on the sample, with a sensitivity varying from 1 to 100 ?g per sample. Our system could represent a simpler alternative to the complex and sophisticated laboratory measurements, such as Inductively Coupled Plasma Mass Spectrometry (ICP-MS) or Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES), officially used by environmental agencies. A 6 month in-situ test, carried out in collaboration with the local Regional Environmental Agency, showed that our system gives results comparable with the ones obtained using existing techniques, but with smaller errors. The methodology developed has been submitted for a patent.

Busetto, E.; Peloi, M.; Rebuffi, L.; Tefouet Kana, E.

2013-05-01

301

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

302

Measurement of angular distribution and polarization of photon-induced fluorescent x rays in thorium and uranium  

NASA Astrophysics Data System (ADS)

The angular distribution and polarization of the L-shell fluorescent x rays excited by 59.57-keV photons in Th and U have been measured. It is found that the L? group of L x rays is isotropic in spatial distribution and unpolarized but, the Ll and L? groups are anisotropically distributed and are polarized. Although no anisotropy of the L? group is detected, it is found to be slightly polarized. The present results contradict the predictions of the calculations of Cooper and Zare [Atomic Collision Processes (Gordon and Breach, New York, 1969)] that after photoionization the magnetic substates of all subshell vacancy states are equally populated. However, the present results confirm the predictions of Flügge, Mehlhorn, and Schmidt [Phys. Rev. Lett. 29, 7 (1972)] that the population distribution of the magnetic substates of all subshell vacancy states with j>1/2 is nonstatistical.

Kahlon, K. S.; Aulakh, H. S.; Singh, N.; Mittal, R.; Allawadhi, K. L.; Sood, B. S.

1991-02-01

303

Comparative x-ray reflectometry and atomic force microscopy of surfaces with non-Gaussian roughness  

NASA Astrophysics Data System (ADS)

Theoretical and experimental investigations have been carried out with the aim of comparing atomic force microscopy (AFM) and x-ray reflectometry (XRR) as methods for characterizing surface roughness. It is shown that AFM gives more appropriate information about the surface roughness in comparison to XRR. The method for estimating the parameters that characterize x-ray scattering on the basis of AFM data is developed.

Mironov, V. L.; Udalov, O. G.; Gribkov, B. A.; Fraerman, A. A.

2008-09-01

304

Synchrotron Radiation Total Reflection X-ray Fluorescence Spectroscopy for Microcontamination Analysis on Silicon Wafer Surfaces  

SciTech Connect

As dimensions in state-of-the-art CMOS devices shrink to less than 0.1 pm, even low levels of impurities on wafer surfaces can cause device degradation. Conventionally, metal contamination on wafer surfaces is measured using Total Reflection X-Ray Fluorescence Spectroscopy (TXRF). However, commercially available TXRF systems do not have the necessary sensitivity for measuring the lower levels of contamination required to develop new CMOS technologies. In an attempt to improve the sensitivity of TXRF, this research investigates Synchrotron Radiation TXRF (SR TXRF). The advantages of SR TXRF over conventional TXRF are higher incident photon flux, energy tunability, and linear polarization. We made use of these advantages to develop an optimized SR TXRF system at the Stanford Synchrotron Radiation Laboratory (SSRL). The results of measurements show that the Minimum Detection Limits (MDLs) of SR TXRF for 3-d transition metals are typically at a level-of 3x10{sup 8} atoms/cm{sup 2}, which is better than conventional TXRF by about a factor of 20. However, to use our SR TXRF system for practical applications, it was necessary to modify a commercially available Si (Li) detector which generates parasitic fluorescence signals. With the modified detector, we could achieve true MDLs of 3x10{sup 8} atoms/cm{sup 2} for 3-d transition metals. In addition, the analysis of Al on Si wafers is described. Al analysis is difficult because strong Si signals overlap the Al signals. In this work, the Si signals are greatly reduced by tuning the incident beam energy below the Si K edge. The results of our measurements show that the sensitivity for Al is limited by x-ray Raman scattering. Furthermore, we show the results of theoretical modeling of SR TXRF backgrounds consisting of the bremsstrahlung generated by photoelectrons, Compton scattering, and Raman scattering. To model these backgrounds, we extended conventional theoretical models by taking into account several aspects particular to SR TXRF. The results of the calculated backgrounds will be compared with experimental data. Based on these calculations, we estimate the improvement of the MDLs as a function of incident beam energy and photon flux density. We will also discuss further improvements in the MDLs through the use of third generation synchrotron radiation sources.

Takaura, Norikatsu

1997-10-01

305

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

306

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

307

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

308

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

309

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

310

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

311

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

312

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

Microsoft Academic Search

We demonstrate that ultralow-level Al impurities on a silicon surface can be measured by using the high-resolution grazing emission x-ray fluorescence (GEXRF) technique combined with synchrotron-radiation excitation. An Al-impurity level of about 1012atoms\\/cm2 was reached by observing the AlKalpha x-ray fluorescence in the resonant Raman-scattering background-``free'' regime by choosing an appropriate beam energy below the SiK absorption edge. Present results

A. Kubala-Kukus; D. Banas; W. Cao; J.-Cl. Dousse; J. Hoszowska; Y. Kayser; M. Pajek; M. Salomé; J. Susini; J. Szlachetko; M. Szlachetko

2009-01-01

313

Three-Dimensional Readout of Flash X-Ray Images of Living Sperm in Water by Atomic-Force Microscopy  

NASA Astrophysics Data System (ADS)

The imaging of living specimens in water by x-ray microscopy can be greatly enhanced with the use of an intense flash x-ray source and sophisticated technologies for reading x-ray images. A subpicosecond x-ray pulse from a laser-produced plasma was used to record the x-ray image of living sea urchin sperm in an x-ray resist. The resist relief was visualized at high resolution by atomic-force microscopy. Internal structure of the sperm head was evident, and the carbon density in a flagellum was estimated from the relief height.

Tomie, T.; Shimizu, H.; Majima, T.; Yamada, M.; Kanayama, T.; Kondo, H.; Yano, M.; Ono, M.

1991-05-01

314

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

315

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

316

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

317

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

318

Characterization of single-crystal sapphire substrates by X-ray methods and atomic force microscopy  

SciTech Connect

The possibility of characterizing a number of practically important parameters of sapphire substrates by X-ray methods is substantiated. These parameters include wafer bending, traces of an incompletely removed damaged layer that formed as a result of mechanical treatment (scratches and marks), surface roughness, damaged layer thickness, and the specific features of the substrate real structure. The features of the real structure of single-crystal sapphire substrates were investigated by nondestructive methods of double-crystal X-ray diffraction and plane-wave X-ray topography. The surface relief of the substrates was investigated by atomic force microscopy and X-ray scattering. The use of supplementing analytical methods yields the most complete information about the structural inhomogeneities and state of crystal surface, which is extremely important for optimizing the technology of substrate preparation for epitaxy.

Prokhorov, I. A.; Zakharov, B. G., E-mail: zakharov@kaluga.rosmail.com [Russian Academy of Sciences, Research Center Space Materials Science, Shubnikov Institute of Crystallography (Kaluga Branch) (Russian Federation); Asadchikov, V. E.; Butashin, A. V.; Roshchin, B. S.; Tolstikhina, A. L. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Zanaveskin, M. L.; Grishchenko, Yu. V.; Muslimov, A. E. [Russian Research Center Kurchatov Institute (Russian Federation); Yakimchuk, I. V.; Volkov, Yu. O.; Kanevskii, V. M.; Tikhonov, E. O. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

2011-05-15

319

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...

320

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

321

K-shell X-ray spectroscopy of atomic nitrogen  

NASA Astrophysics Data System (ADS)

Photoionization cross-section measurements for atomic nitrogen in the region of the K-edge have been made at the Advanced Light Source for the first time and are suitably reproduced by R-matrix calculations.

Sant'Anna, M. M.; Schlachter, A. S.; Öhrwall, G.; Stolte, W. C.; Lindle, D. W.; McLaughlin, B. M.

2012-11-01

322

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

323

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

324

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

325

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

326

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

327

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

328

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

329

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

330

[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

331

Moseley's Work on X-Rays and Atomic Number.  

ERIC Educational Resources Information Center

|Highlights the connection between the achievements of Moseley and the spectrum of the hydrogen atom, the Bohr theory, and Slater's rules for screening constants. Uses modern data to show that Moseley's equation is actually an approximation and discusses the significance of this fact. (JRH)|

Haigh, C. W.

1995-01-01

332

Quantitative effective atomic number imaging using simultaneous x-ray absorption and phase shift measurement  

SciTech Connect

A scanning type x-ray imaging system which measures the absorption and differential phase shift in a material quantitatively and simultaneously has been developed. The absorption and differential phase are used to obtain the effective atomic number of organic material samples which closely reflects their chemical composition. An effective atomic number map of polymer fibers has been obtained. The experimentally obtained effective atomic numbers of these polymers agree well with the corresponding calculated values.

Mukaide, Taihei; Watanabe, Masatoshi; Takada, Kazuhiro; Fukuda, Kazunori; Noma, Takashi [Nanomaterials Technology Development Center, Canon Inc., 30-2, Shimomaruko 3-chome, Ohta-ku, Tokyo 146-8501 (Japan); Iida, Atsuo [Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1, Oho Tsukuba, Ibaraki 305-0801 (Japan)

2011-03-14

333

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

334

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

335

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

336

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

337

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

338

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

339

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

340

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

341

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

342

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

343

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

344

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

345

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

346

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

347

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

348

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

349

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

350

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

351

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

352

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

353

[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

354

Scanning Transmission Electron microscope Studies of Deep-Frozen Unfixed Muscle Correlated with Spatial Localization of Intracellular Elements by Fluorescent X-Ray Analysis  

PubMed Central

Thin sections of deep-frozen unfixed muscle were studied in a scanning electron microscope modified for transmission imaging and equipped with a “cryostage” for vacuum compatibility of hydrated tissue. With an energy-dispersive x-ray analysis system, intracellular atomic species in the scan beam path were identified by their fluorescent x-rays and spatially localized in correlation with the electron optical image of the microstructure. Marked differences are noted between the ultrastructure of deep-frozen hydrated muscle and that of fixed dehydrated muscle. In frozen muscle, myofibrils appear to be composed of previously undescribed longitudinal structures between 400-1000 Ĺ wide (“macromyofilaments”). The usual myofilaments, mitochondria, and sarcoplasmic reticulum were not seen unless the tissue was “fixed” before examination. Fluorescent x-ray analysis of the spatial location of constituent elements clearly identified all elements heavier than Na. Intracellular Cl was relatively higher than expected. Images

Bacaner, Marvin; Broadhurst, John; Hutchinson, Thomas; Lilley, John

1973-01-01

355

X-Ray Fluorescence Holographic Study on a Single-Crystal Thin Film of a Rewritable Optical Media  

SciTech Connect

In this article, we discuss X-ray fluorescence holography (XFH) using a third-generation synchrotron radiation facility through an application to a DVD-RAM material thin film. Three-dimensional atomic images were obtained at 100 K around the Ge atoms in a Ge2Sb2Te5 single-crystal thin film by means of XFH technique at the beamline BL37XU of the SPring-8 to clarify the high-speed writing and erasing mechanism of this DVD material. From the obtained XFH images, it was concluded that the single-crystal thin film has a mixture of rocksalt and zinc-blende structures. In addition, the images indicate large distortions associated with the existence of vacancies of the Ge(Sb) site. The present XFH results are in good agreement with the previous XAFS results, which has predicted a phase transition due to an umbrella flip motion of the Ge atom000.

Hosokawa, S.; Ozaki, T. [Center for Materials Research Using Third-Generation Synchrotron Radiation Facilities, Hiroshima Institute of Technology, Hiroshima 731-5193 (Japan); Hayashi, K. [Institute of Materials Research, Tohoku University, Sendai 980-8577 (Japan); Happo, N.; Horii, K. [Faculty of Information Sciences, Hiroshima City University, Hiroshima 731-3194 (Japan); Fons, P.; Tominaga, J. [Center for Applied Near-Field Optics Research, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8562 (Japan); Kolobov, A. V. [Center for Applied Near-Field Optics Research, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8562 (Japan); Laboratoire de Physicochimie de la Matiere Condensee, Universite Montpellier II, 34095 Montpellier Cedex 5 (France)

2007-01-19

356

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

357

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

358

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

359

X-ray atomic scattering factors of low-Z ions with a core hole  

SciTech Connect

Short and intense x-ray pulses may be used for atomic-resolution diffraction imaging of single biological molecules. One of the dominant damage mechanisms is atomic ionization, resulting in a large fraction of atoms with core holes. We calculated the atomic scattering factor of atoms with atomic charge numbers between 3 and 10 in different ionization states with and without a core hole. Our results show that orbital occupation and the change of the orbitals upon core ionization (core relaxation) have a significant impact on the diffraction pattern.

Hau-Riege, Stefan P. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States)

2007-10-15

360

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

361

Chemical Analysis of Impurity Boron Atoms in Diamond Using Soft X-ray Emission Spectroscopy  

SciTech Connect

To analyze the local structure and/or chemical states of boron atoms in boron-doped diamond, which can be synthesized by the microwave plasma-assisted chemical vapor deposition method (CVD-B-diamond) and the temperature gradient method at high pressure and high temperature (HPT-B-diamond), we measured the soft X-ray emission spectra in the CK and BK regions of B-diamonds using synchrotron radiation at the Advanced Light Source (ALS). X-ray spectral analyses using the fingerprint method and molecular orbital calculations confirm that boron atoms in CVD-B-diamond substitute for carbon atoms in the diamond lattice to form covalent B-C bonds, while boron atoms in HPT-B-diamond react with the impurity nitrogen atoms to form hexagonal boron nitride. This suggests that the high purity diamond without nitrogen impurities is necessary to synthesize p-type B-diamond semiconductors.

Muramatsu, Yasuji; Iihara, Junji; Takebe, Toshihiko; Denlinger, Jonathan D.

2008-03-29

362

Chemical analysis of impurity boron atoms in diamond using soft X-ray emission spectroscopy.  

PubMed

To analyze the local structure and/or chemical states of boron atoms in boron-doped diamond, which can be synthesized by the microwave plasma-assisted chemical vapor deposition method (CVD-B-diamond) and the temperature gradient method at high pressure and high temperature (HPT-B-diamond), we measured the soft X-ray emission spectra in the CK and BK regions of B-diamonds using synchrotron radiation at the Advanced Light Source (ALS). X-ray spectral analyses using the fingerprint method and molecular orbital calculations confirm that boron atoms in CVD-B-diamond substitute for carbon atoms in the diamond lattice to form covalent B-C bonds, while boron atoms in HPT-B-diamond react with the impurity nitrogen atoms to form hexagonal boron nitride. This suggests that the high purity diamond without nitrogen impurities is necessary to synthesize p-type B-diamond semiconductors. PMID:18614820

Muramatsu, Yasuji; Iihara, Junji; Takebe, Toshihiko; Denlinger, Jonathan D

2008-07-01

363

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

364

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

365

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

366

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

367

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

368

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

369

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

370

A Novel Antimatter Detector Based on X-Ray Deexcitation of Exotic Atoms  

Microsoft Academic Search

We propose a novel antiparticle detector. The gaseous antiparticle spectrometer (GAPS) effects particle identification through the characteristic X-rays emitted by antiparticles when they form exotic atoms in gases. GAPS obtains particularly high grasp (effective area-solid angle product) at lower particle energies, where conventional schemes are most limited in their utility. The concept is simple and lightweight, so it can be

Kaya Mori; Charles J. Hailey; Edward A. Baltz; William W. Craig; Marc Kamionkowski; William T. Serber; Piero Ullio

2002-01-01

371

Coherent x-ray emission from hollow Xe atoms  

NASA Astrophysics Data System (ADS)

We investigated small Xe clusters subject to intense ultrashort laser radiation. The dynamics and evolution of the cluster plasma is described by a relativistic time-dependent 3-D molecular dynamics model and a detailed atomic physics model describing the formation of hollow Xe atoms. At a peak laser intensity of (1-5)x10^20 W/cm^2 the model predicts inversions in a number of states distributed in several ionization stages in agreement with experimental observations [1,2]. The particle simulation model suggests that at laser intensities below 10^20 W/cm^2 the outer electrons form a low-density uniform plasma, while at higher intensities the electrons may behave collectively in a manner similar to that described by the "collective oscillation model" [1,2]. [1] W. A. Schroeder, F. G. Omenetto, A. B. Borisov, J. W. Longworth, A. McPherson, C. Jordan, K. Boyer, K. Kondo, and C. K. Rhodes, J. Phys. B 31, 5031 (1998) [2] W. A. Schroeder, T. R. Nelson, A. B. Borisov, J. W. Longworth, K. Boyer, and C. K. Rhodes, J. Phys. B 34, 297 (2001)

Petrov, G. M.; Davis, J.; Kepple, P.; Dasgupta, A.; Clark, R.; Velikovich, A.; Borisov, A. B.; Rhodes, C. K.

2004-11-01

372

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

373

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

374

Disentangling atomic-layer-specific x-ray absorption spectra by Auger electron diffraction spectroscopy  

NASA Astrophysics Data System (ADS)

In order to investigate the electronic and magnetic structures of each atomic layer at subsurface, we have proposed a new method, Auger electron diffraction spectroscopy, which is the combination of x-ray absorption spectroscopy (XAS) and Auger electron diffraction (AED) techniques. We have measured a series of Ni LMM AED patterns of the Ni film grown on Cu(001) surface for various thicknesses. Then we deduced a set of atomic-layer-specific AED patterns in a numerical way. Furthermore, we developed an algorithm to disentangle XANES spectra from different atomic layers using these atomic-layer-specific AED patterns. Surface and subsurface core level shift were determined for each atomic layer.

Matsui, Fumihiko; Matsushita, Tomohiro; Kato, Yukako; Hashimoto, Mie; Daimon, Hiroshi

2009-11-01

375

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

376

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

377

Extending synchrotron-based atomic physics experiments into the hard X-ray region  

SciTech Connect

The high-brightness, hard x-ray beams available from third-generation synchrotron sources are opening new opportunities to study the deepest inner shells of atoms, an area where little work has been done and phenomena not observed in less tightly bound inner-shells are manifested. In addition scattering processes which are weak at lower energies become important, providing another tool to investigate atomic structure as well as an opportunity to study photon/atom interactions beyond photoabsorption. In this contribution the authors discuss some of the issues related to extending synchrotron-based atomic physics experiments into the hard x-ray region from the physical and the experimental point of view. They close with a discussion of a technique, resonant Raman scattering, that may prove invaluable in determining the spectra of the very highly-excited states resulting from the excitation of deep inner shells.

LeBrun, T. [Argonne National Lab., IL (United States). Physics Div.

1996-12-31

378

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

379

Two-photon-induced x-ray emission in neon atoms  

SciTech Connect

We investigated the resonant x-ray emission from a neon atom induced by the two-photon population of a double-core-hole excited state. Two qualitatively different schemes of this process are studied: The first one involves an off-resonant intermediate single-core-hole state; the second scheme passes through a resonant core-ionized intermediate state. The numerical simulations of the resonant x-ray emission performed for different peak intensities and pulse durations show significant population of the double-core-hole final states. Therefore, rather strong two-photon absorption-induced x-ray emission is predicted for both studied schemes. Thus, high counting rates in experimental measurements are expected.

Sun Yuping; Wang Chuankui [College of Physics and Electronics, Shandong Normal University, 250014 Jinan (China); Theoretical Chemistry, School of Biotechnology, Royal Institute of Technology, S-10691 Stockholm (Sweden); Rinkevicius, Zilvinas; Gel'mukhanov, Faris [Theoretical Chemistry, School of Biotechnology, Royal Institute of Technology, S-10691 Stockholm (Sweden); Carniato, Stephane; Simon, Marc; Taieeb, Richard [Laboratoire de Chimie Physique Matiere et Rayonnement, Universite Pierre et Marie Curie Universite Paris 06, Unite de Mixte de Recherche (UMR) 7614, F-75005 Paris (France); Laboratoire de Chimie Physique Matiere et Rayonnement, Centre National de la Recherche Scientifique, UMR 7614, F-75005 Paris (France)

2010-10-15

380

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

381

Intershell correlations in nonresonant Compton scattering of an X-ray photon by an atom  

SciTech Connect

The role of intershell correlations in nonresonant Compton scattering of an X-ray photon by a free multielectron atom is studied theoretically for the Ar atom. The results of calculation are of a predictive nature. The developed mathematical formalism is general in nature and can be applied to a wide set of elements from the Periodic Table, for which the description of the wavefunctions of scattering states in the nonrelativistic Hartree-Fock approximation remains correct.

Hopersky, A. N., E-mail: hopersky_vm_1@rgups.ru; Nadolinsky, A. M.; Ikoeva, K. Kh.; Khoroshavina, O. A. [Rostov State Railway University (Russian Federation)

2011-11-15

382

Detection of hot muonic hydrogen atoms emitted in vacuum using x-rays  

SciTech Connect

Negative muons are stopped in solid layers of hydrogen and neon. Muonic hydrogen atoms can drift to the neon layer where the muon is immediately transferred. It was found that the time structure of the muonic neon X-rays follows the exponential law where the rate is the same as the disappearance rate of [mu][sup -]p atoms. The pp[mu]-formation rate and the muon transfer rate to deuterium are deduced.

Jacot-Guillarmod, R. (Fribourg Univ. (Switzerland)); Bailey, J.M. (Liverpool Univ. (United Kingdom)); Beer, G.A.; Knowles, P.E.; Mason, G.R.; Olin, A. (Victoria Univ., BC (Canada)); Beveridge, J.L.; Marshall, G.M. (TRIUMF, Vancouver, BC (Canada)); Brewer, J.H.; Forster, B.M. (British Columbia Univ., Vancouver, BC (Canada)); Huber, T.M. (Gustavus Adolphus Coll., St. Peter, MN (United States)); Kammel, P

1992-01-01

383

Detection of hot muonic hydrogen atoms emitted in vacuum using x-rays  

SciTech Connect

Negative muons are stopped in solid layers of hydrogen and neon. Muonic hydrogen atoms can drift to the neon layer where the muon is immediately transferred. It was found that the time structure of the muonic neon X-rays follows the exponential law where the rate is the same as the disappearance rate of {mu}{sup -}p atoms. The pp{mu}-formation rate and the muon transfer rate to deuterium are deduced.

Jacot-Guillarmod, R. [Fribourg Univ. (Switzerland); Bailey, J.M. [Liverpool Univ. (United Kingdom); Beer, G.A.; Knowles, P.E.; Mason, G.R.; Olin, A. [Victoria Univ., BC (Canada); Beveridge, J.L.; Marshall, G.M. [TRIUMF, Vancouver, BC (Canada); Brewer, J.H.; Forster, B.M. [British Columbia Univ., Vancouver, BC (Canada); Huber, T.M. [Gustavus Adolphus Coll., St. Peter, MN (United States); Kammel, P.; Zmeskal, J. [Oesterreichische Akademie der Wissenschaften, Vienna (Austria). Inst. fuer Mittelenergiephysik; Kunselman, A.R. [Wyoming Univ., Laramie, WY (United States); Petitjean, C. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1992-12-31

384

Intershell correlations in nonresonant Compton scattering of an X-ray photon by an atom  

NASA Astrophysics Data System (ADS)

The role of intershell correlations in nonresonant Compton scattering of an X-ray photon by a free multielectron atom is studied theoretically for the Ar atom. The results of calculation are of a predictive nature. The developed mathematical formalism is general in nature and can be applied to a wide set of elements from the Periodic Table, for which the description of the wavefunctions of scattering states in the nonrelativistic Hartree-Fock approximation remains correct.

Hopersky, A. N.; Nadolinsky, A. M.; Ikoeva, K. Kh.; Khoroshavina, O. A.

2011-11-01

385

Characteristic L Absorption of X-rays for Elements of Atomic Numbers 62 to 77  

Microsoft Academic Search

Characteristic L x-ray aborption wave-lengths for nine elements of atomic numbers 62 to 77.-Since the L absorption wave-lengths had been determined for elements of atomic numbers 55 to 60, 74, and 78 to 92, it was of interest to fill in the gaps. Accordingly compounds of samarium (62), gadolinium (64), dysprosium (66), erbium (68), ytterbium (70), tantalum (73), tungsten (74),

J. M. Cork

1923-01-01

386

Atomic data for the ITER Core Imaging X-ray Spectrometer  

SciTech Connect

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

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

2012-06-15

387

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

388

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

389

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

390

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

391

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

392

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...

393

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

394

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

NASA Astrophysics Data System (ADS)

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

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

2009-08-01

395

[Determination of the valence change of copper concentrate ore sample during depositing by conventional X-ray fluorescence spectrometer].  

PubMed

The peak position and line shape of S Kalpha, S Kbeta satellite line, and the ratio of (S Kalpha / S Kbeta), (Cu Lalpha / Cu Kalpha), and (Fe Lalpha / Fe Kalpha) of copper concentrate samples with different depositing methods were determined by a conventional X-ray fluorescence spectrometer. It is concluded that the valence of S, Cu and Fe changed during depositing in accordance with the changes of the lines, Copper concentrate sample (main mine phase is chalcopyrite, containing a little pyrite) was oxidized apparently after 2 years depositing. Part of S2-, Cu+ and Fe2+ in the sample were oxidized to high valence, and the sulphur atom combined with oxygen atom. The oxidation of the sample was influenced markedly by the storing method. PMID:16201381

Ying, Xiao-hu; Chen, Shao-hong

2005-06-01

396

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

397

X-ray diffraction study of aluminum oxides. Communication III. Analysis of structure of various aluminum oxides by x-ray method of radial distribution of atoms  

SciTech Connect

The x-ray method of radial distribution of atoms (RDA) has been used to characterize the transitional forms of aluminum oxide; the character of structural changes has been demonstrated in the transition from low-temperature forms to high-temperature forms.

Ushakov, V.A.; Moroz, E.M.; Levitskii, E.A.

1986-04-01

398

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

399

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

400

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

401

Theory of x-ray absorption by laser-dressed atoms  

SciTech Connect

An ab initio theory is devised for the x-ray photoabsorption cross section of atoms in the field of a moderately intense optical laser (800 nm, 10{sup 13} W/cm{sup 2}). The laser dresses the core-excited atomic states, which introduces a dependence of the cross section on the angle between the polarization vectors of the two linearly polarized radiation sources. We use the Hartree-Fock-Slater approximation to describe the atomic many-particle problem in conjunction with a nonrelativistic quantum-electrodynamic approach to treat the photon-electron interaction. The continuum wave functions of ejected electrons are treated with a complex absorbing potential that is derived from smooth exterior complex scaling. The solution to the two-color (x-ray plus laser) problem is discussed in terms of a direct diagonalization of the complex symmetric matrix representation of the Hamiltonian. Alternative treatments with time-independent and time-dependent non-Hermitian perturbation theories are presented that exploit the weak interaction strength between x rays and atoms. We apply the theory to study the photoabsorption cross section of krypton atoms near the K edge. A pronounced modification of the cross section is found in the presence of the optical laser.

Buth, Christian; Santra, Robin [Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2007-03-15

402

X-ray fluorescent spectroscopy and quantum chemistry investigation of electronic structure of the palladium[60]fullerene complex with bidentate ligand 1,1?-bis(diphenylphosphino)ferrocene  

NASA Astrophysics Data System (ADS)

The electronic structure of organometallic fullerene complex C60Pd(P(C6H5)2)2Fe(C5H4)2 has been investigated using X-ray fluorescent spectroscopy and density functional theory. It was shown that, the electronic state of carbon atoms incorporated into the complex can be related to the electronic state of carbon atoms that constituted the structural units C60, P(C6H5)3, and Fe(C5H5)2. In the studied complex, palladium atom acts as a bridge in the transferring of electronic density from the ligand phosphorus atoms to the fullerene cage.

Bulusheva, L. G.; Okotrub, A. V.; Gusel'Nikov, A. V.; Yumatov, V. D.; Bashilov, V. V.; Sokolov, V. I.

2005-07-01

403

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.

404

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

405

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

406

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

407

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

408

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

409

Double-resonant x-ray and microwave absorption: Atomic spectroscopy of precessional orbital and spin dynamics  

Microsoft Academic Search

We show that double-resonance spectra recorded during the simultaneous absorption of x-ray and microwave (MW) photons are a fingerprint of the perturbed electronic configuration of atomic species driven to ferromagnetic resonance. X-ray absorption measurements performed as a function of x-ray energy and polarization over the FeL2,3 edges of single-crystal yttrium-iron garnet reveal MW-induced multiplet features related to angular momentum transfer

G. Boero; S. Rusponi; P. Bencok; R. Meckenstock; J.-U. Thiele; F. Nolting; P. Gambardella

2009-01-01

410

X-ray study of atomic ordering in self-assembled Ge islands grown on Si(001)  

SciTech Connect

X-ray diffuse scattering in the vicinity of basis-forbidden Bragg reflections were measured for samples with uncapped self-assembled Ge islands epitaxially grown on Si(001). Our results provide evidence of atomically ordered SiGe domains in both islands and wetting layer. The modeling of x-ray profiles reveals the presence of antiphase boundaries separating the ordered domains in a limited region of the islands. X-ray order parameter results were independently supported by Raman measurements.

Malachias, A. [Departamento de Fisica, Universidade Federal de Minas Gerais, C.P. 702, CEP 30123-970, Belo Horizonte, MG (Brazil); European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex (France); Schuelli, T. U. [CEA/Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Medeiros-Ribeiro, G. [Laboratorio Nacional de Luz Sincrotron, C.P. 6192, CEP 13084-971, Campinas, SP (Brazil); Cancado, L. G. [Departamento de Fisica, Universidade Federal de Minas Gerais, C.P. 702, CEP 30123-970, Belo Horizonte, MG (Brazil); Stoffel, M.; Schmidt, O. G. [Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, D-70569 Stuttgart (Germany); Metzger, T. H. [European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex (France); Magalhaes-Paniago, R. [Departamento de Fisica, Universidade Federal de Minas Gerais, C.P. 702, CEP 30123-970, Belo Horizonte, MG (Brazil); Laboratorio Nacional de Luz Sincrotron, C.P. 6192, CEP 13084-971, Campinas, SP (Brazil)

2005-10-15

411

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

412

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

413

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

414

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

415

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

416

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

417

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

418

Atomic structure of Au-nanoparticles on silica support by X-ray PDF study  

SciTech Connect

We investigated the atomic structure of gold nanoparticles with an average size of 5 nm in diameter, supported by silica. We used high-energy X-ray diffraction and the atomic pair distribution function (PDF) to probe the local atomic structure. Measurements were performed from 25 to 950 C. The structure is approximately fcc in average but exhibits small distortions. The structural distortion increases with the temperature and could be related to the catalytic activity of gold nanoparticles. Above 425 C, rapid particle growth and coalescence were observed.

Dmowski, W. [University of Tennessee, Knoxville (UTK); Yin, Hongfeng [ORNL; Dai, Sheng [ORNL; Overbury, Steven {Steve} H [ORNL; Egami, T. [University of Tennessee, Knoxville (UTK)

2010-01-01

419

Atomic Structure of Au Nanoparticles on a Silica Support by an X-ray PDF Study  

SciTech Connect

We investigated the atomic structure of gold nanoparticles with an average size of {approx}5 nm in diameter, supported by silica. We used high-energy X-ray diffraction and the atomic pair distribution function (PDF) to probe the local atomic structure. Measurements were performed from 25 to 950 C. The structure is approximately fcc in average but exhibits small distortions. The structural distortion increases with the temperature and could be related to the catalytic activity of gold nanoparticles. Above 425 C, rapid particle growth and coalescence were observed.

Dmowski, Wojtek; Yin, Hongfeng; Dai, Sheng; Overbury, Steven H.; Egami, Takeshi (Tennessee-K); (ORNL)

2010-05-04

420

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

421

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

422

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

423

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

424

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

425

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

426

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

427

[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

428

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

429

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

430

X-ray photon spectroscopy calculations  

SciTech Connect

X-ray photons - as many other particles - interact with matter producing secondary radiation that carries useful information about the atoms comprising the target. The availability of intense sources of highly monochromatic X-rays and the great improvement in detector technology intensified research in X-ray spectrometry in the last twenty years. New techniques allowed the attenuation coefficients and the physics of the atom to be better known: Extended X-ray Absorption Fine Structure (EXAFS), X-ray Absorption Near Edge Structure (XANES), and Inelastic X-ray Scattering Spectroscopy (IXSS). Old techniques, like X-ray Fluorescence (XRF), gained in precision thus extending the horizon of applicability to new elements and energy ranges, and consequently Energy Dispersive X-ray Fluorescence (EDXRF) and Synchrotron Radiation X-ray Fluorescence (SRXRF) were evolved. Particle induced X-ray emission spectroscopy also benefited from this improvement. The field of application of X-ray spectrometry has grown from atomic, to nuclear, to plasma physics, to astrophysics. In this work the authors summarize the knowledge recently gained about how the intensity due to multiple scattering perturbs the first-order terms of the three processes of main interest in X-ray spectrometry between 1 keV and 100 keV: the photoelectric, the Rayleigh and the Compton effects. They show that the contribution of a few orders of scattering, calculated in the frame of transport theory, allows the construction of a theoretical X-ray spectrum that matches well experimental data from targets of homogeneous composition and infinite thickness. 99 refs., 15 figs.

Fernandez, J.E.; Molinari, V.G. [Univ. of Bologna (Italy)

1991-12-31

431

Atomic number scaling of the nickel-like soft x-ray lasers  

SciTech Connect

The authors report the review of the experimental results obtained at the Institute of Laser Engineering, Osaka University, of the soft X-ray lasing in various Ni-like ions whose atomic numbers range from 47(Ag) to 66(Dy). The lasing wavelengths are between 14 nm and 5 nm. X-ray lasing in these materials were obtained when the plasma profiles were properly controlled in time and space by irradiation of curved slab targets with multiple laser pulses. They also describe the original work of the atomic physics calculations which provide the transition energies, transition probabilities and other atomic constants for Ni-like ion species whose atomic numbers range from 36 to 92 calculated with GRASP code (multi-configuration Dirac Fock code) and YODA code (relativistic distorted wave code). Based on these atomic constants, they have calculated the kinetics of the population inversion with a simplified rate equation model in conjunction with a one-dimensional hydrodynamic code to find out the desired pumping conditions. They show a possibility for significant improvement in the pumping efficiency with the use of a picosecond laser irradiating a properly configured preformed plasma. Finally, a simplified estimation of the pumping efficiency is described based on the atomic constants and plasma physics issues.

Daido, H.; Ninomiya, S.; Imani, T. [Osaka Univ., Suita, Osaka (Japan). Inst. of Laser Engineering] [and others

1997-03-30

432

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

433

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

434

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

435

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

436

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

437

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

438

Atomic plasma excitations in the field of a soft x-ray laser  

NASA Astrophysics Data System (ADS)

The interaction of atoms with short-wavelength radiation at ultra-high intensities is described by plasma excitation. In contrast to former works on optical radiation and ponderomotive motion of quasi-free electrons, the excitation of correlated and bound electrons is considered here. The ponderomotive motion of a free electron is included as a special case. Values for the energy transfer from the radiation field to an atom are obtained in fair agreement with the unexpectedly high charge states of xenon recently observed at the soft x-ray free-electron laser FLASH.

Richter, M.

2011-04-01

439

Concepts in x-ray physics.  

SciTech Connect

A basic introduction to the theory underlying x-ray processes is provided. After general remarks on the practical advantages of using x-rays for probing matter, the derivation of the minimal-coupling Hamiltonian within nonrelativistic quantum electrodynamics is outlined. Perturbation theory is reviewed and applied to describe x-ray-induced processes. In connection with x-ray absorption, inner-shell binding energies and the photon energy dependence of the x-ray absorption cross section are discussed. In the context of x-ray scattering, atomic and molecular scattering factors are introduced, the complex index of refraction is derived, and the nonrelativistic theory of Compton scattering is described. The final topic is x-ray fluorescence and Auger decay of inner-shell-excited systems.

Santra, R.; Chemical Sciences and Engineering Division

2009-01-28

440

Resonance inelastic scattering of an x-ray photon by the xenon atom  

NASA Astrophysics Data System (ADS)

The effect of many-particle and relativistic effects on the absolute values and the shape of the doubly differential cross section of resonance inelastic scattering of a linearly polarized x-ray photon by the free xenon atom in the energy region of the K ionization threshold is studied theoretically. The evolution of the spatially extended structure of the scattering cross section in the K?,? structure of the x-ray emission spectrum of the xenon atom is demonstrated. The calculations were performed in the dipole approximation for the anomalous dispersion part of the total amplitude of probability of inelastic scattering and in the impulse approximation for the contact part of this amplitude. The radial relaxation of electronic shells, the spin-orbit splitting, the double excitation/ionization of the ground atomic state, as well as the Auger and radiative decays of the atomic core vacancies being formed were taken into account. In constructing the probability amplitude of the process, the relativistic effects were taken into account as a passage from the nonrelativistic Hartree-Fock wave functions to the relativistic Dirac-Hartree-Fock wave functions of the one-particle scattering states and as the passage (for the radiative transition amplitudes) to the relativistic form of the operator of the photon-atom interaction. The calculation results are predictive in character and, at the incident photon energy 34.42 keV, agree well with the results of the synchrotron experiment.

Khoperski?, A. N.; Nadolinski?, A. M.; Yavna, V. A.; Kasprzhitski?, A. S.

2007-11-01

441

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

442

Comparison of atomic absorption, mass and X-ray spectrometry techniques using dissolution-based and solid sampling methods for the determination of silver in polymeric samples  

Microsoft Academic Search

In this work, the capabilities and limitations of solid sampling techniques – laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS), wavelength dispersive X-ray fluorescence spectrometry (WD-XRFS) and solid sampling electrothermal atomic absorption spectrometry (SS-ETAAS) – for the determination of silver in polymers have been evaluated and compared to those of acid digestion and subsequent Ag determination using pneumatic nebulization ICPMS

Isabel De Schrijver; Maite Aramendia; Laszlo Vincze; Martín Resano; Ann Dumoulin; Frank Vanhaecke

2