Sample records for x-ray photoelectron spectroscopy

  1. In-situ X-ray Photoelectron Spectroscopy of a Catalyst for Artificial...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In-situ X-ray Photoelectron Spectroscopy of a Catalyst for Artificial Photosynthesis Monday, June 30, 2014 Plants and other organisms use a process called photosynthesis to produce...

  2. A new endstation at the Swiss Light Source for ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy measurements of liquid solutions

    SciTech Connect (OSTI)

    Brown, Matthew A.; Redondo, Amaia Beloqui; Duyckaerts, Nicolas; Mächler, Jean-Pierre [Institute for Chemical and Bioengineering, ETH Zürich, CH-8093 Zürich (Switzerland)] [Institute for Chemical and Bioengineering, ETH Zürich, CH-8093 Zürich (Switzerland); Jordan, Inga; Wörner, Hans Jakob [Laboratory of Physical Chemistry, ETH Zürich, CH-8093 Zürich (Switzerland)] [Laboratory of Physical Chemistry, ETH Zürich, CH-8093 Zürich (Switzerland); Lee, Ming-Tao; Ammann, Markus; Nolting, Frithjof; Kleibert, Armin; Huthwelker, Thomas; Birrer, Mario; Honegger, Juri; Wetter, Reto [Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland)] [Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Bokhoven, Jeroen A. van [Institute for Chemical and Bioengineering, ETH Zürich, CH-8093 Zürich (Switzerland) [Institute for Chemical and Bioengineering, ETH Zürich, CH-8093 Zürich (Switzerland); Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland)

    2013-07-15T23:59:59.000Z

    A new liquid microjet endstation designed for ultraviolet (UPS) and X-ray (XPS) photoelectron, and partial electron yield X-ray absorption (XAS) spectroscopies at the Swiss Light Source is presented. The new endstation, which is based on a Scienta HiPP-2 R4000 electron spectrometer, is the first liquid microjet endstation capable of operating in vacuum and in ambient pressures up to the equilibrium vapor pressure of liquid water at room temperature. In addition, the Scienta HiPP-2 R4000 energy analyzer of this new endstation allows for XPS measurements up to 7000 eV electron kinetic energy that will enable electronic structure measurements of bulk solutions and buried interfaces from liquid microjet samples. The endstation is designed to operate at the soft X-ray SIM beamline and at the tender X-ray Phoenix beamline. The endstation can also be operated using a Scienta 5 K ultraviolet helium lamp for dedicated UPS measurements at the vapor-liquid interface using either He I or He II ? lines. The design concept, first results from UPS, soft X-ray XPS, and partial electron yield XAS measurements, and an outlook to the potential of this endstation are presented.

  3. Atmospheric Corrosion of Silver Investigated by X-ray Photoelectron Spectroscopy Dissertation

    E-Print Network [OSTI]

    Atmospheric Corrosion of Silver Investigated by X-ray Photoelectron Spectroscopy Dissertation Atmospheric corrosion is a costly problem. Accelerated laboratory tests, such as the salt fog chamber, have been created to predict corrosion of materials without the need to expose them over long periods

  4. In situ x-ray photoelectron spectroscopy for electrochemical reactions in ordinary solvents

    SciTech Connect (OSTI)

    Masuda, Takuya [Global Research Center for Environment and Energy Based on Nanomaterials Science (GREEN), National Institute for Materials Science (NIMS), Tsukuba 305-0044 (Japan) [Global Research Center for Environment and Energy Based on Nanomaterials Science (GREEN), National Institute for Materials Science (NIMS), Tsukuba 305-0044 (Japan); PRESTO, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 333-0012 (Japan); Yoshikawa, Hideki; Kobata, Masaaki; Kobayashi, Keisuke [Synchrotron X-ray Station at SPring-8, National Institute for Materials Science (NIMS), Sayo, Hyogo 679-5148 (Japan)] [Synchrotron X-ray Station at SPring-8, National Institute for Materials Science (NIMS), Sayo, Hyogo 679-5148 (Japan); Noguchi, Hidenori [Global Research Center for Environment and Energy Based on Nanomaterials Science (GREEN), National Institute for Materials Science (NIMS), Tsukuba 305-0044 (Japan) [Global Research Center for Environment and Energy Based on Nanomaterials Science (GREEN), National Institute for Materials Science (NIMS), Tsukuba 305-0044 (Japan); PRESTO, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 333-0012 (Japan); Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan); International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044 (Japan); Kawasaki, Tadahiro [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603 (Japan)] [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603 (Japan); Uosaki, Kohei [Global Research Center for Environment and Energy Based on Nanomaterials Science (GREEN), National Institute for Materials Science (NIMS), Tsukuba 305-0044 (Japan) [Global Research Center for Environment and Energy Based on Nanomaterials Science (GREEN), National Institute for Materials Science (NIMS), Tsukuba 305-0044 (Japan); Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan); International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044 (Japan)

    2013-09-09T23:59:59.000Z

    In situ electrochemical X-ray photoelectron spectroscopy (XPS) apparatus, which allows XPS at solid/liquid interfaces under potential control, was constructed utilizing a microcell with an ultra-thin Si membrane, which separates vacuum and a solution. Hard X-rays from a synchrotron source penetrate into the Si membrane surface exposed to the solution. Electrons emitted at the Si/solution interface can pass through the membrane and be analyzed by an analyzer placed in vacuum. Its operation was demonstrated for potential-induced Si oxide growth in water. Effect of potential and time on the thickness of Si and Si oxide layers was quantitatively determined at sub-nanometer resolution.

  5. X-ray photoelectron spectroscopy of gallium nitride films grown by radical-beam gettering epitaxy

    SciTech Connect (OSTI)

    Rogozin, I. V. [Berdyansk State Pedagogical University (Ukraine)], E-mail: rogozin@bdpu.org; Kotlyarevsky, M. B. [Academy of Management and Information Technology (Ukraine)

    2007-05-15T23:59:59.000Z

    Thin GaN films were grown on GaAs(111) substrates by radical-beam gettering epitaxy. The structural quality of the films was studied by high-resolution x-ray diffraction. The chemical composition of the GaAs surface and GaN film was studied by x-ray photoelectron spectroscopy. It is shown that Ga-N and As-N bonds are formed on the GaAs surface at initial growth stages at low temperatures. The state of the film-substrate interface was studied. It was found that prolonged annealing of GaN films in nitrogen radicals shifts the composition to nitrogen excess.

  6. Novel Approaches to Soft X-ray Spectroscopy: Scanning TransmissionX-ray Microscopy and Ambient Pressure X-Ray PhotoelectronSpectroscopy

    SciTech Connect (OSTI)

    Bluhm, Hendrik; Gilles, Mary K.; Mun, Simon B.; Tyliszczak, Tolek

    2006-02-01T23:59:59.000Z

    This workshop focused on novel spectroscopies at Beamlines 11.0.2, 5.3.2 and 9.3.2 at the ALS. The workshop brought together users from a wide range of fields to highlight recent experimental and technical developments both in scanning transmission X-ray spectroscopy (STXM) and ambient pressure photoelectron spectroscopy (APPES). The morning session featured talks on experiments involving new developments at the STXM, while the afternoon session was devoted to those using APXPS. In the morning session, Tolek Tyliszczak discussed the improved detector developments at the STXM, such as an avalanche photodiode detector and fluorescence and electron detection, as well as the continued development of in situ cells for heating, gas flow, and electrochemical cells. Of these, only the avalanche photodiode in combination with a novel multichannel photon-counting system is in routine use in time-resolved studies. Bartel Van Waeyenberge (Ghent University) presented results of magnetic imaging with a time resolution of 70-100 ps combined with a lateral resolution of 20-40 nm performed with the STXM (Beamline 11.0.2). As a complement to the time-domain ''pump-and-probe'' measurements, they developed a frequency-domain ''sine-excitation'' technique in order to study specific eigenmodes of these ferromagnetic patterns with high spatial resolution. This new approach was used to study the gyrotropic vortex motions in micron-sized ferromagnetic patterns. Adam Hitchcock (McMaster University) presented the development, in collaboration with Daniel Guay (INRS, Varennes) and Sherry Zhang, of the apparatus and techniques for applying STXM to in-situ studies of electrochemistry, in particular electrochromism in polyaniline. In addition, substantial progress was reported on a joint project to develop substrates and methods for chemically selective lithography of multilayer polymer systems. Selective patterns, such as that displayed in the figure, can now be written efficiently with the bend magnet STXM on Beamline 5.3.2. Yves Acremann (SSRL) discussed time and spatially resolved X-ray magnetic circular dichroism (XMCD) experiments on spin transfer devices at the STXM (Beamline 11.0.2). These elegant experiments explore time resolved measurements of the magnetization dynamics within a 100 x 150 nm sample influenced by a spin-polarized current. This experiment shows that the magnetization in these magnetic nanostructures are not uniform, as they are influenced by the Oersted field of the charge current needed to generate the spin current. The implementation of a novel multichannel photon counting system in combination with an avalanche photon detector decreased the data-acquisition time by a factor of 10, owing to its ability to resolve the structure of multi bunch mode. Gordon E. Brown, Jr. (Stanford University and SSRL) described ''Applications of STXM to Microbial Bioweathering and Biomineralization''. In the interaction of bacteria with ferrihydrite nanoparticles, microenvironments that were very different than the bulk material were observed, showing that bulk thermodynamics may not be useful for predicting micro phases. Gordon also presented work showing that iron nanoparticles are attracted to the negatively charged bacteria and form a coating that reduces iron oxide minerals. The afternoon session started with presentations by Simon Mun and Hendrik Bluhm, who discussed the current status and the future plans for the two APPES end-stations at the ALS, which are located at Beamlines 9.3.2 and 11.0.2, respectively. In both end-stations, samples can be measured in gaseous environments at pressures of up to several Torr, which makes possible the investigation of numerous phenomena, in particular in the fields of atmospheric and environmental science as well as heterogeneous catalysis. Specific examples of the application of APPES were shown in the following presentations. John Hemminger (University of California, Irvine) reported on APPES investigations at Beamlines 9.3.2 and 11.0.2 of the interaction of alkali halide surfaces with water. The m

  7. First-principles core-level X-ray photoelectron spectroscopy calculation on arsenic defects in silicon crystal

    SciTech Connect (OSTI)

    Kishi, Hiroki; Miyazawa, Miki; Matsushima, Naoki; Yamauchi, Jun [Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama-shi, Kanagawa-ken 223-8522 (Japan)

    2014-02-21T23:59:59.000Z

    We investigate the X-ray photoelectron spectroscopy (XPS) binding energies of As 3d in Si for various defects in neutral and charged states by first-principles calculation. It is found that the complexes of a substitutional As and a vacancy in charged and neutral states explain the experimentally observed unknown peak very well.

  8. Reactive ZnO/Ti/ZnO interfaces studied by hard x-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Knut, Ronny, E-mail: Ronny.Knut@physics.gu.se; Lindblad, Rebecka; Rensmo, Håkan; Karis, Olof [Department of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala (Sweden); Grachev, Sergey; Faou, Jean-Yvon; Søndergård, Elin [Unité Mixte CNRS/Sain-Gobain Recherche, 39 Quai Lucien Lefranc, 93303 Aubervilliers (France); Gorgoi, Mihaela [Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Str. 15, D-12489 Berlin (Germany)

    2014-01-28T23:59:59.000Z

    The chemistry and intermixing at buried interfaces in sputter deposited ZnO/Ti/ZnO thin layers were studied by hard x-ray photoelectron spectroscopy. The long mean free path of the photoelectrons allowed for detailed studies of the oxidation state, band bending effects, and intrinsic doping of the buried interfaces. Oxidation of the Ti layer was observed when ZnO was deposited on top. When Ti is deposited onto ZnO, Zn Auger peaks acquire a metallic character indicating a strong reduction of ZnO at the interface. Annealing of the stack at 200?°C results in further reduction of ZnO and oxidation of Ti. Above 300?°C, oxygen transport from the bulk of the ZnO layer takes place, leading to re-oxidation of ZnO at the interface and further oxidation of Ti layer. Heating above 500?°C leads to an intermixing of the layers and the formation of a Zn{sub x}TiO{sub y} compound.

  9. Soft X-Ray and Vacuum Ultraviolet Based Spectroscopy of the Actinides

    SciTech Connect (OSTI)

    Tobin, J G

    2011-03-17T23:59:59.000Z

    The subjects of discussion included: VUV photoelectron spectroscopy, X-ray photoelectron spectroscopy, Synchrotron-radiation-based photoelectron spectroscopy, Soft x-ray absorption spectroscopy, Soft x-ray emission spectroscopy, Inverse photoelectron spectroscopy, Bremstrahlung Isochromat Spectroscopy, Low energy IPES, Resonant inverse photoelectron spectroscopy.

  10. X-ray photoelectron spectroscopy study of para-substituted benzoic acids chemisorbed to aluminum oxide thin films

    SciTech Connect (OSTI)

    Kreil, Justin; Ellingsworth, Edward; Szulczewski, Greg [Department of Chemistry, The University of Alabama, Shelby Hall, 250 Hackberry Lane, Tuscaloosa, Alabama 35487 (United States)] [Department of Chemistry, The University of Alabama, Shelby Hall, 250 Hackberry Lane, Tuscaloosa, Alabama 35487 (United States)

    2013-11-15T23:59:59.000Z

    A series of para-substituted, halogenated (F, Cl, Br, and I) benzoic acid monolayers were prepared on the native oxide of aluminum surfaces by solution self-assembly and spin-coating techniques. The monolayers were characterized by x-ray photoelectron spectroscopy (XPS) and water contact angles. Several general trends are apparent. First, the polarity of the solvent is critical to monolayer formation. Protic polar solvents produced low coverage monolayers; in contrast, nonpolar solvents produced higher coverage monolayers. Second, solution deposition yields a higher surface coverage than spin coating. Third, the thickness of the monolayers determined from XPS suggests the plane of the aromatic ring is perpendicular to the surface with the carboxylate functional group most likely binding in a bidentate chelating geometry. Fourth, the saturation coverage (?2.7 × 10{sup 14} molecules cm{sup ?2}) is independent of the para-substituent.

  11. Electronic structure of Al- and Ga-doped ZnO films studied by hard X-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Gabás, M.; Ramos Barrado, José R. [Lab. de Materiales and Superficies, Dpto. de Física Aplicada I, Universidad de Málaga, 29071 Málaga (Spain); Torelli, P. [Laboratorio TASC, IOM-CNR, S.S. 14 km 163.5, Basovizza, I-34149 Trieste (Italy); Barrett, N. T. [CEA, DSM/IRAMIS/SPCSI, F-91191 Gif-sur-Yvette Cedex (France); Sacchi, M. [Synchrotron SOLEIL, BP 48, 91192 Gif-sur-Yvette, France and Institut des NanoSciences de Paris, UPMC Paris 06, CNRS UMR 7588, 4 Place Jussieu, 75005 Paris (France)

    2014-01-01T23:59:59.000Z

    Al- and Ga-doped sputtered ZnO films (AZO, GZO) are semiconducting and metallic, respectively, despite the same electronic valence structure of the dopants. Using hard X-ray photoelectron spectroscopy we observe that both dopants induce a band in the electronic structure near the Fermi level, accompanied by a narrowing of the Zn 3d/O 2p gap in the valence band and, in the case of GZO, a substantial shift in the Zn 3d. Ga occupies substitutional sites, whereas Al dopants are in both substitutional and interstitial sites. The latter could induce O and Zn defects, which act as acceptors explaining the semiconducting character of AZO and the lack of variation in the optical gap. By contrast, mainly substitutional doping is consistent with the metallic-like behavior of GZO.

  12. Sub-nanosecond time-resolved ambient-pressure X-ray photoelectron spectroscopy setup for pulsed and constant wave X-ray light sources

    SciTech Connect (OSTI)

    Shavorskiy, Andrey; Slaughter, Daniel S.; Zegkinoglou, Ioannis; Rude, Bruce S.; Bluhm, Hendrik [Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Neppl, Stefan; Cryan, James P.; Siefermann, Katrin R.; Weise, Fabian; Lin, Ming-Fu; Bacellar, Camila; Ziemkiewicz, Michael P.; Fraund, Matthew W.; Khurmi, Champak; Wright, Travis W.; Schoenlein, Robert W.; Gessner, Oliver, E-mail: ogessner@lbl.gov [Ultrafast X-ray Science Laboratory, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Hertlein, Marcus P.; Tyliszczak, Tolek [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Huse, Nils [Ultrafast X-ray Science Laboratory, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Physics Department, University of Hamburg and Max-Planck Institute for Structure and Dynamics of Matter, 22761 Hamburg (Germany); and others

    2014-09-15T23:59:59.000Z

    An apparatus for sub-nanosecond time-resolved ambient-pressure X-ray photoelectron spectroscopy studies with pulsed and constant wave X-ray light sources is presented. A differentially pumped hemispherical electron analyzer is equipped with a delay-line detector that simultaneously records the position and arrival time of every single electron at the exit aperture of the hemisphere with ?0.1 mm spatial resolution and ?150 ps temporal accuracy. The kinetic energies of the photoelectrons are encoded in the hit positions along the dispersive axis of the two-dimensional detector. Pump-probe time-delays are provided by the electron arrival times relative to the pump pulse timing. An average time-resolution of (780 ± 20) ps (FWHM) is demonstrated for a hemisphere pass energy E{sub p} = 150 eV and an electron kinetic energy range KE = 503–508 eV. The time-resolution of the setup is limited by the electron time-of-flight (TOF) spread related to the electron trajectory distribution within the analyzer hemisphere and within the electrostatic lens system that images the interaction volume onto the hemisphere entrance slit. The TOF spread for electrons with KE = 430 eV varies between ?9 ns at a pass energy of 50 eV and ?1 ns at pass energies between 200 eV and 400 eV. The correlation between the retarding ratio and the TOF spread is evaluated by means of both analytical descriptions of the electron trajectories within the analyzer hemisphere and computer simulations of the entire trajectories including the electrostatic lens system. In agreement with previous studies, we find that the by far dominant contribution to the TOF spread is acquired within the hemisphere. However, both experiment and computer simulations show that the lens system indirectly affects the time resolution of the setup to a significant extent by inducing a strong dependence of the angular spread of electron trajectories entering the hemisphere on the retarding ratio. The scaling of the angular spread with the retarding ratio can be well approximated by applying Liouville's theorem of constant emittance to the electron trajectories inside the lens system. The performance of the setup is demonstrated by characterizing the laser fluence-dependent transient surface photovoltage response of a laser-excited Si(100) sample.

  13. Band offsets of TiZnSnO/Si heterojunction determined by x-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Sun, R. J.; Jiang, Q. J.; Yan, W. C.; Feng, L. S.; Lu, B.; Ye, Z. Z. [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Li, X. F. [Key Laboratory of Advanced Display and System Application, Ministry of Education, Shanghai University, Shanghai 200072 (China); Li, X. D. [Xinyi PV Products (Anhui) Holdings LTD, Xinyi PV Glass Industrial Zone, No. 2 Xinyi Road, ETDZ, Wuhu 241009 (China); Lu, J. G., E-mail: lujianguo@zju.edu.cn [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Key Laboratory of Advanced Display and System Application, Ministry of Education, Shanghai University, Shanghai 200072 (China)

    2014-09-28T23:59:59.000Z

    X-ray photoelectron spectroscopy (XPS) was utilized to measure the valence band offset (?E{sub V}) of the TiZnSnO (TZTO)/Si heterojunction. TZTO films were deposited on Si (100) substrates using magnetron sputtering at room temperature. By using the Zn 2p{sub 3/2} and Sn 3d{sub 5/2} energy levels as references, the value of ?E{sub V} was calculated to be 2.69 ± 0.1 eV. Combining with the experimental optical energy band gap of 3.98 eV for TZTO extracted from the UV-vis transmittance spectrum, the conduction band offset (?E{sub C}) was deduced to be 0.17 ± 0.1 eV at the interface. Hence, the energy band alignment of the heterojunction was determined accurately, showing a type-I form. This will be beneficial for the design and application of TZTO/Si hybrid devices.

  14. In-situ X-ray photoelectron spectroscopy studies of water on metals and oxides at ambient conditions

    SciTech Connect (OSTI)

    Salmeron, Miquel; Yamamoto, S.; Bluhm, H.; Andersson, K.; Ketteler, G.; Ogasawara, H.; Salmeron, M.; Nilsson, A.

    2007-10-29T23:59:59.000Z

    X-ray photoelectron spectroscopy (XPS) is a powerful tool for surface and interface analysis, providing the elemental composition of surfaces and the local chemical environment of adsorbed species. Conventional XPS experiments have been limited to ultrahigh vacuum (UHV) conditions due to a short mean free path of electrons in a gas phase. The recent advances in instrumentation coupled with third-generation synchrotron radiation sources enables in-situ XPS measurements at pressures above 5 Torr. In this review, we describe the basic design of the ambient pressure XPS setup that combines differential pumping with an electrostatic focusing. We present examples of the application of in-situ XPS to studies of water adsorption on the surface of metals and oxides including Cu(110), Cu(111), TiO2(110) under environmental conditions of water vapor pressure. On all these surfaces we observe a general trend where hydroxyl groups form first, followed by molecular water adsorption. The importance of surface OH groups and their hydrogen bonding to water molecules in water adsorption on surfaces is discussed in detail.

  15. Analysis of the surface of tricalcium silicate during the induction period by X-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Bellmann, F., E-mail: frank.bellmann@uni-weimar.de [Institute for Building Materials Science, Bauhaus University Weimar, 99423 Weimar (Germany); Sowoidnich, T.; Ludwig, H.-M. [Institute for Building Materials Science, Bauhaus University Weimar, 99423 Weimar (Germany)] [Institute for Building Materials Science, Bauhaus University Weimar, 99423 Weimar (Germany); Damidot, D. [Ecole des Mines de Douai, Civil and Environmental Engineering Department, 941 rue Charles Bourseul, BP 10838, 59508 Doua cedex (France)] [Ecole des Mines de Douai, Civil and Environmental Engineering Department, 941 rue Charles Bourseul, BP 10838, 59508 Doua cedex (France)

    2012-09-15T23:59:59.000Z

    X-ray photoelectron spectroscopy allows the analysis of surface layers with a thickness of a few nanometers. The method is sensitive to the chemical environment of the atoms since the binding energy of the electrons depends on the chemical bonds to neighboring atoms. It has been applied to the hydration of tricalcium silicate (Ca{sub 3}SiO{sub 5}, C{sub 3}S) by analyzing a sample after 30 min of hydration. Also two references have been investigated namely anhydrous C{sub 3}S and intermediate phase in order to enable a quantitative evaluation of the experimental data. In the hydrated C{sub 3}S sample, the analyzed volume (0.2 mm{sup 2} surface by 13 nm depth) contained approximately 44 wt.% of C{sub 3}S and 56 wt.% of intermediate phase whereas C-S-H was not detected. Scanning Electron Microscopy data and geometric considerations indicate that the intermediate phase forms a thin layer having a thickness of approximately 2 nm and covers the complete surface instead of forming isolated clusters.

  16. Using “Tender” x-ray ambient pressure x-Ray photoelectron spectroscopy as a direct probe of solid-liquid interface

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Axnanda, Stephanus [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Crumlin, Ethan J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mao, Baohua [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chinese Academy of Sciences, Shanghai (Republic of China); Rani, Sana [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chang, Rui [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chinese Academy of Sciences, Shanghai (Republic of China); Karlsson, Patrik G. [VG Scienta,Uppsala (Sweden); Edwards, Mårten O. M. [VG Scienta,Uppsala (Sweden); Lundqvist, Måns [VG Scienta,Uppsala (Sweden); Moberg, Robert [VG Scienta,Uppsala (Sweden); Ross, Phil [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hussain, Zahid [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Liu, Zhi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chinese Academy of Sciences, Shanghai (Republic of China); Shanghai Tech Univ., Shanghai (China)

    2015-05-07T23:59:59.000Z

    We report a new method to probe the solid-liquid interface through the use of a thin liquid layer on a solid surface. An ambient pressure XPS (AP-XPS) endstation that is capable of detecting high kinetic energy photoelectrons (7 keV) at a pressure up to 110 Torr has been constructed and commissioned. Additionally, we have deployed a “dip & pull” method to create a stable nanometers-thick aqueous electrolyte on platinum working electrode surface. Combining the newly constructed AP-XPS system, “dip & pull” approach, with a “tender” X-ray synchrotron source (2 keV–7 keV), we are able to access the interface between liquid and solid dense phases with photoelectrons and directly probe important phenomena occurring at the narrow solid-liquid interface region in an electrochemical system. Using this approach, we have performed electrochemical oxidation of the Pt electrode at an oxygen evolution reaction (OER) potential. Under this potential, we observe the formation of both Pt²? and Pt?? interfacial species on the Pt working electrode in situ. We believe this thin-film approach and the use of “tender” AP-XPS highlighted in this study is an innovative new approach to probe this key solid-liquid interface region of electrochemistry.

  17. Using “Tender” x-ray ambient pressure x-Ray photoelectron spectroscopy as a direct probe of solid-liquid interface

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Axnanda, Stephanus; Crumlin, Ethan J.; Mao, Baohua; Rani, Sana; Chang, Rui; Karlsson, Patrik G.; Edwards, Mårten O. M.; Lundqvist, Måns; Moberg, Robert; Ross, Phil; et al

    2015-05-07T23:59:59.000Z

    We report a new method to probe the solid-liquid interface through the use of a thin liquid layer on a solid surface. An ambient pressure XPS (AP-XPS) endstation that is capable of detecting high kinetic energy photoelectrons (7 keV) at a pressure up to 110 Torr has been constructed and commissioned. Additionally, we have deployed a “dip & pull” method to create a stable nanometers-thick aqueous electrolyte on platinum working electrode surface. Combining the newly constructed AP-XPS system, “dip & pull” approach, with a “tender” X-ray synchrotron source (2 keV–7 keV), we are able to access the interface between liquidmore »and solid dense phases with photoelectrons and directly probe important phenomena occurring at the narrow solid-liquid interface region in an electrochemical system. Using this approach, we have performed electrochemical oxidation of the Pt electrode at an oxygen evolution reaction (OER) potential. Under this potential, we observe the formation of both Pt²? and Pt?? interfacial species on the Pt working electrode in situ. We believe this thin-film approach and the use of “tender” AP-XPS highlighted in this study is an innovative new approach to probe this key solid-liquid interface region of electrochemistry.« less

  18. Elemental content of enamel and dentin after bleaching of teeth (a comparative study between laser-induced breakdown spectroscopy and x-ray photoelectron spectroscopy)

    SciTech Connect (OSTI)

    Imam, H. [National Institute of Laser Enhanced Sciences, NILES, Cairo University, Giza (Egypt)] [National Institute of Laser Enhanced Sciences, NILES, Cairo University, Giza (Egypt); Ahmed, Doaa [Department of Restorative Sciences, Faculty of Dentistry, Alexandria University, Alexandria (Egypt)] [Department of Restorative Sciences, Faculty of Dentistry, Alexandria University, Alexandria (Egypt); Eldakrouri, Ashraf [National Institute of Laser Enhanced Sciences, NILES, Cairo University, Giza (Egypt) [National Institute of Laser Enhanced Sciences, NILES, Cairo University, Giza (Egypt); Department of Optometry and Vision Science, College of Applied Medical Science, King Saud University, Riyadh (Saudi Arabia)

    2013-06-21T23:59:59.000Z

    The elemental content of the superficial and inner enamel as well as that of dentin was analyzed using laser-induced breakdown spectroscopy (LIBS) and x-ray photoelectron spectroscopy (XPS) of bleached and unbleached tooth specimens. It is thus clear from the spectral analysis using both the LIBS and XPS technique that elemental changes (though insignificant within the scopes of this study) of variable intensities do occur on the surface of the enamel and extend deeper to reach dentin. The results of the LIBS revealed a slight reduction in the calcium levels in the bleached compared to the control specimens in all the different bleaching groups and in both enamel and dentin. The good correlation found between the LIBS and XPS results demonstrates the possibility of LIBS technique for detection of minor loss in calcium and phosphorus in enamel and dentin.

  19. Angle-resolved environmental X-ray photoelectron spectroscopy: A new laboratory setup for photoemission studies at pressures up to 0.4 Torr

    SciTech Connect (OSTI)

    Mangolini, F.; Wabiszewski, G. E.; Egberts, P. [Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, 220 S. 33rd Street, Philadelphia, Pennsylvania 19104 (United States); Ahlund, J.; Backlund, K.; Karlsson, P. G. [VG Scienta AB, Box 15120, SE-750 15 Uppsala (Sweden); Adiga, V. P.; Streller, F. [Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, Pennsylvania 19104 (United States); Wannberg, B. [VG Scienta AB, Box 15120, SE-750 15 Uppsala (Sweden); BW Particle Optics AB, P.O. Box 55, SE-822 22 Alfta (Sweden); Carpick, R. W. [Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, 220 S. 33rd Street, Philadelphia, Pennsylvania 19104 (United States); Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, Pennsylvania 19104 (United States)

    2012-09-15T23:59:59.000Z

    The paper presents the development and demonstrates the capabilities of a new laboratory-based environmental X-ray photoelectron spectroscopy system incorporating an electrostatic lens and able to acquire spectra up to 0.4 Torr. The incorporation of a two-dimensional detector provides imaging capabilities and allows the acquisition of angle-resolved data in parallel mode over an angular range of 14 Degree-Sign without tilting the sample. The sensitivity and energy resolution of the spectrometer have been investigated by analyzing a standard Ag foil both under high vacuum (10{sup -8} Torr) conditions and at elevated pressures of N{sub 2} (0.4 Torr). The possibility of acquiring angle-resolved data at different pressures has been demonstrated by analyzing a silicon/silicon dioxide (Si/SiO{sub 2}) sample. The collected angle-resolved spectra could be effectively used for the determination of the thickness of the native silicon oxide layer.

  20. Measurement of the valence band-offset in a PbSe/ZnO heterojunction by x-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Li Lin; Qiu Jijun; Weng Binbin; Yuan Zijian; Shi Zhisheng [School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States); Li Xiaomin; Gan Xiaoyan [State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Sellers, Ian R. [Deparment of Physics, University of Oklahoma, Norman, Oklahoma 73019 (United States)

    2012-12-24T23:59:59.000Z

    A heterojunction of PbSe/ZnO has been grown by molecular beam epitaxy. X-ray photoelectron spectroscopy was used to directly measure the valence-band offset (VBO) of the heterojunction. The VBO, {Delta}E{sub V}, was determined as 2.51 {+-} 0.05 eV using the Pb 4p{sup 3/2} and Zn 2p{sup 3/2} core levels as a reference. The conduction-band offset, {Delta}E{sub C}, was, therefore, determined to be 0.59 {+-} 0.05 eV based on the above {Delta}E{sub V} value. This analysis indicates that the PbSe/ZnO heterojunction forms a type I (Straddling Gap) heterostructure.

  1. Band alignment study of lattice-matched In{sub 0.49}Ga{sub 0.51}P and Ge using x-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Owen, Man Hon Samuel, E-mail: m.owen.sg@ieee.org, E-mail: yeo@ieee.org; Zhou, Qian; Gong, Xiao; Yeo, Yee-Chia, E-mail: m.owen.sg@ieee.org, E-mail: yeo@ieee.org [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 119260 (Singapore); Zhang, Zheng; Pan, Ji Sheng [Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 (Singapore); Loke, Wan Khai; Wicaksono, Satrio; Yoon, Soon Fatt [School of Electrical and Electronic Engineering, Nanyang Technological University (NTU), Nanyang Avenue, Singapore 639798 (Singapore); Tok, Eng Soon [Department of Physics, National University of Singapore, Singapore 117551 (Singapore)

    2014-09-08T23:59:59.000Z

    Lattice-matched In{sub 0.49}Ga{sub 0.51}P was grown on a p-type Ge(100) substrate with a 10° off-cut towards the (111) by low temperature molecular beam epitaxy, and the band-alignment of In{sub 0.49}Ga{sub 0.51}P on Ge substrate was obtained by high resolution x-ray photoelectron spectroscopy. The valence band offset for the InGaP/Ge(100) interface was found to be 0.64?±?0.12?eV, with a corresponding conduction band offset of 0.60?±?0.12?eV. The InGaP/Ge interface is found to be of the type I band alignment.

  2. Theoretical standards in x-ray spectroscopies

    SciTech Connect (OSTI)

    Not Available

    1992-01-01T23:59:59.000Z

    We propose to extend our state-of-the-art, ab initio XAFS (X-ray absorption fine structure) codes, FEFF. Our current work has been highly successful in achieving accurate, user-friendly XAFS standards, exceeding the performance of both tabulated standards and other codes by a considerable margin. We now propose to add the capability to treat more complex materials. This includes multiple-scattering, polarization dependence, an approximate treatment of XANES (x-ray absorption near edge structure), and other improvements. We also plan to adapt FEFF to other spectroscopies, e.g. photoelectron diffraction (PD) and diffraction anomalous fine structure (DAFS).

  3. A promising concept for using near-surface measuring angles in angle-resolved x-ray photoelectron spectroscopy considering elastic scattering effects

    SciTech Connect (OSTI)

    Oswald, S.; Oswald, F. [IFW Dresden, Postfach 270116, D-01171 Dresden (Germany)

    2011-02-01T23:59:59.000Z

    The increasing number of applications of very thin films requires both reliable thin-layer and interface characterization. A powerful method for characterization in the nanometer thickness range is the angle-resolved x-ray photoelectron spectroscopy (ARXPS). This is a nondestructive depth-profiling method, which can provide elemental content as well as chemical information. Two of the drawbacks of ARXPS are, that it requires dedicated mathematical modeling and that, at least up until now, its use has been restricted away from near-surface angles. In this paper we present a method for the mathematical description of a few, hitherto unaccounted, measurement effects in order to improve the simulations of ARXPS data for complex surface structures. As an immediate application, we propose a simple algorithm to consider the effects of elastic scattering in the standard ARXPS data interpretation, which in principle would allow the use of the whole angular range for the analysis; thus leading to a significant increase in the usable information content from the measurements. The potential of this approach is demonstrated with model calculations for a few thin film examples.

  4. Interfacial chemistry and valence band offset between GaN and Al{sub 2}O{sub 3} studied by X-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Duan, T. L.; Ang, D. S. [School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore)] [School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore); Pan, J. S. [Institute of Materials Research and Engineering, A-STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 (Singapore)] [Institute of Materials Research and Engineering, A-STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 (Singapore)

    2013-05-20T23:59:59.000Z

    The interface region between Ga-face n-type GaN and Al{sub 2}O{sub 3} dielectric (achieved via atomic-layer deposition or ALD) is investigated by X-ray photoelectron spectroscopy (XPS). An increase in the Ga-O to Ga-N bond intensity ratio following Al{sub 2}O{sub 3} deposition implies that the growth of an interfacial gallium sub-oxide (GaO{sub x}) layer occurred during the ALD process. This finding may be ascribed to GaN oxidation, which may still happen following the reduction of a thin native GaO{sub x} by trimethylaluminum (TMA) in the initial TMA-only cycles. The valence band offset between GaN and Al{sub 2}O{sub 3}, obtained using both core-level and valence band spectra, is found to vary with the thickness of the deposited Al{sub 2}O{sub 3}. This observation may be explained by an upward energy band bending at the GaN surface (due to the spontaneous polarization induced negative bound charge on the Ga-face GaN) and the intrinsic limitation of the XPS method for band offset determination.

  5. Profiling of the SiO2 -SiC Interface Using X-ray Photoelectron Spectroscopy R. N. Ghosh

    E-Print Network [OSTI]

    Ghosh, Ruby N.

    energy loss spectroscopy, have revealed a 1.5-6 nm thick layer with a monotonically decaying C 4 School of Electrical & Computer Engineering, Purdue Univ., W. Lafayette, IN 47907 ABSTRACT techniques have been utilized to study this problem. Atomic H3.7.1 Mat. Res. Soc. Symp. Vol. 640 © 2001

  6. Chemical order in Ge{sub x}As{sub y}Se{sub 1-x-y} glasses probed by high resolution X-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Xu, S. W. [Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); College of Applied Sciences, Beijing University of Technology, Beijing100124 (China); Wang, R. P.; Luther-Davies, B. [Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Kovalskiy, A. [Department of Physics and Astronomy, Austin Peay State University, Clarksville, Tennessee 37043 (United States); Miller, A. C.; Jain, H. [Department of Materials Science and Engineering, Lehigh University, 5 East Packer Avenue, Bethlehem, Pennsylvania 18015-3195 (United States)

    2014-02-28T23:59:59.000Z

    We have measured high-resolution x-ray photoelectron spectra of Ge{sub x}As{sub y}Se{sub 1-x-y} glasses with a mean coordination number (MCN) from 2.2 to 2.78. The valence band spectra showed that a number of Se–Se–Se trimers can be found in Se-rich samples, whilst multiband features induced by phase separation can be observed in extremely Se-poor samples. When the Ge, As, and Se 3d spectra were decomposed into several doublets, which correspond, respectively, to different chemical environments, the perfect AsSe{sub 3/2} pyramidal and GeSe{sub 4/2} tetrahedral structures in Se-rich samples gradually evolved into defect structures, including As–As and Ge–Ge homopolar bonds, with increasing Ge and As concentrations. Two transition-like features were found at MCN?=?2.5 and 2.64–2.72 that correspond first to the disappearance of Se-chains in the glass network and, subsequently, destruction of the perfect GeSe{sub 4/2} tetrahedral structures, respectively.

  7. X-ray spectroscopy of low-mass X-ray binaries

    E-Print Network [OSTI]

    Juett, Adrienne Marie, 1976-

    2004-01-01T23:59:59.000Z

    I present high-resolution X-ray grating spectroscopy of neutron stars in low-mass X-ray binaries (LMXBs) using instruments onboard the Chandra X-ray Observatory and the X-ray Multi-Mirror Mission (XMM-Newton). The first ...

  8. Probing electronic and vibrational dynamics in molecules by time-resolved photoelectron, Auger-electron, and X-ray photon scattering spectroscopy

    E-Print Network [OSTI]

    Bennett, K; Kowalewski, M; Mukamel, S

    2015-01-01T23:59:59.000Z

    division, O?ce of Basic Energy Sciences, O?ce of Science,U.S. Department of Energy as well as from the Nationalthe photoelectrons’ kinetic energy. This is given by the di?

  9. Deduction of the chemical state and the electronic structure of Nd{sub 2}Fe{sub 14}B compound from X-ray photoelectron spectroscopy core-level and valence-band spectra

    SciTech Connect (OSTI)

    Wang, Jing; Liang, Le [School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhang, Lanting, E-mail: lantingzh@sjtu.edu.cn, E-mail: lmsun@sjtu.edu.cn [School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Hirano Institute for Materials Innovation, Shanghai Jiao Tong University, Shanghai 200240 (China); Sun, Limin, E-mail: lantingzh@sjtu.edu.cn, E-mail: lmsun@sjtu.edu.cn [Instrumental Analysis Center, Shanghai Jiao Tong University, Shanghai 200240 (China); Hirano, Shinichi [Hirano Institute for Materials Innovation, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2014-10-28T23:59:59.000Z

    Characterization of chemical state and electronic structure of the technologically important Nd{sub 2}Fe{sub 14}B compound is attractive for understanding the physical nature of its excellent magnetic properties. X-ray photoelectron spectroscopy (XPS) study of such rare-earth compound is important and also challenging due to the easy oxidation of surface and small photoelectron cross-sections of rare-earth 4f electrons and B 2p electrons, etc. Here, we reported an investigation based on XPS spectra of Nd{sub 2}Fe{sub 14}B compound as a function of Ar ion sputtering time. The chemical state of Fe and that of B in Nd{sub 2}Fe{sub 14}B compound can be clearly determined to be 0 and ?3, respectively. The Nd in Nd{sub 2}Fe{sub 14}B compound is found to have the chemical state of close to +3 instead of +3 as compared with the Nd in Nd{sub 2}O{sub 3}. In addition, by comparing the valence-band spectrum of Nd{sub 2}Fe{sub 14}B compound to that of the pure Fe, the contributions from Nd, Fe, and B to the valence-band structure of Nd{sub 2}Fe{sub 14}B compound is made more clear. The B 2p states and B 2s states are identified to be at ?11.2 eV and ?24.6 eV, respectively, which is reported for the first time. The contribution from Nd 4f states can be identified both in XPS core-level spectrum and XPS valence-band spectrum. Although Nd 4f states partially hybridize with Fe 3d states, Nd 4f states are mainly localized in Nd{sub 2}Fe{sub 14}B compound.

  10. In-operando hard X-ray photoelectron spectroscopy study on the impact of current compliance and switching cycles on oxygen and carbon defects in resistive switching Ti/HfO{sub 2}/TiN cells

    SciTech Connect (OSTI)

    Sowinska, Malgorzata, E-mail: sowinska@ihp-microelectronics.com; Bertaud, Thomas; Walczyk, Damian; Calka, Pauline; Walczyk, Christian [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Thiess, Sebastian [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg (Germany); Alff, Lambert [Institute of Materials Science, Technische Universität Darmstadt, 64287 Darmstadt (Germany); Schroeder, Thomas [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Brandenburgische Technische Universität, Konrad-Zuse-Strasse 1, 03046 Cottbus (Germany)

    2014-05-28T23:59:59.000Z

    In this study, direct experimental materials science evidence of the important theoretical prediction for resistive random access memory (RRAM) technologies that a critical amount of oxygen vacancies is needed to establish stable resistive switching in metal-oxide-metal samples is presented. In detail, a novel in-operando hard X-ray photoelectron spectroscopy technique is applied to non-destructively investigates the influence of the current compliance and direct current voltage sweep cycles on the Ti/HfO{sub 2} interface chemistry and physics of resistive switching Ti/HfO{sub 2}/TiN cells. These studies indeed confirm that current compliance is a critical parameter to control the amount of oxygen vacancies in the conducting filaments in the oxide layer during the RRAM cell operation to achieve stable switching. Furthermore, clear carbon segregation towards the Ti/HfO{sub 2} interface under electrical stress is visible. Since carbon impurities impact the oxygen vacancy defect population under resistive switching, this dynamic carbon segregation to the Ti/HfO{sub 2} interface is suspected to negatively influence RRAM device endurance. Therefore, these results indicate that the RRAM materials engineering needs to include all impurities in the dielectric layer in order to achieve reliable device performance.

  11. SMB, X-ray Absorption Spectroscopy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiation Protection245C Unlimited ReleaseWelcome to theAbsorption Spectroscopy X-ray

  12. Atomic force microscopy and x-ray photoelectron spectroscopy investigations of the morphology and chemistry of a PdCl{sub 2}/SnCl{sub 2} electroless plating catalysis system adsorbed onto shape memory alloy particles

    SciTech Connect (OSTI)

    Silvain, J.F.; Fouassier, O.; Lescaux, S. [Institut de Chimie de la Matiere Condensee de Bordeaux (ICMCB) - CNRS, Universite de Bordeaux 1, 87 Avenue du Dr A. Schweitzer, F-33608 PESSAC (France); Veeco, Z.I. de la Gaudree, 11 Rue Marie Poussepin, F-91412 Dourdain (France)

    2004-11-01T23:59:59.000Z

    A study of the different stages of the electroless deposition of copper on micronic NiTi shape memory alloy particles activated by one-step and two-step methods has been conducted from both a chemical and a morphological point of view. The combination of x-ray photoelectron spectroscopy (XPS) measurements and atomic force microscopy (AFM) imaging has allowed detection of the distribution of the formed compounds and depth quantification and estimation of the surface topographic parameters. For the two-step method, at the sensitization of the early stages, it is observed by AFM that Sn is absorbed in form of clusters that tend to completely cover the surface and form a continuous film. XPS analysis have shown that Sn and Pd are first absorbed in form of oxide (SnO{sub 2} and PdO) and hydroxide [Sn(OH){sub 4}]. After the entire sensitization step, the NiTi substrate is covered with Sn-based compounds. After the sensitization and the activation steps the powder roughness increases. Behavior of the Sn and Pd growth for the one-step method does not follow the behavior found for the two-step method. Indeed, XPS analysis shows a three-dimensional (3D) growth of Pd clusters on top of a mixture of metallic tin, oxide (SnO) and hydroxide [Sn(OH){sub 2}]. These Pd clusters are covered with a thin layer of Pd-oxide contamination induced by the electroless process. The mean roughness for the one-step and two-step processes are equivalent. After copper deposition, the decrease of mean roughness is attributed to a filling of surface valleys, observed after the Sn-Pd coating step.

  13. Soft X-Ray Microscopy and Spectroscopy at the Molecular Environmental...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Soft X-Ray Microscopy and Spectroscopy at the Molecular Environmental Science Beamline at the Advanced Light Source. Soft X-Ray Microscopy and Spectroscopy at the Molecular...

  14. Theoretical standards in x-ray spectroscopies. Annual progress report, 1991--1992

    SciTech Connect (OSTI)

    Not Available

    1992-09-01T23:59:59.000Z

    We propose to extend our state-of-the-art, ab initio XAFS (X-ray absorption fine structure) codes, FEFF. Our current work has been highly successful in achieving accurate, user-friendly XAFS standards, exceeding the performance of both tabulated standards and other codes by a considerable margin. We now propose to add the capability to treat more complex materials. This includes multiple-scattering, polarization dependence, an approximate treatment of XANES (x-ray absorption near edge structure), and other improvements. We also plan to adapt FEFF to other spectroscopies, e.g. photoelectron diffraction (PD) and diffraction anomalous fine structure (DAFS).

  15. Soft-x-ray spectroscopy study of nanoscale materials

    SciTech Connect (OSTI)

    Guo, J.-H.

    2005-07-30T23:59:59.000Z

    The ability to control the particle size and morphology of nanoparticles is of crucial importance nowadays both from a fundamental and industrial point of view considering the tremendous amount of high-tech applications. Controlling the crystallographic structure and the arrangement of atoms along the surface of nanostructured material will determine most of its physical properties. In general, electronic structure ultimately determines the properties of matter. Soft X-ray spectroscopy has some basic features that are important to consider. X-ray is originating from an electronic transition between a localized core state and a valence state. As a core state is involved, elemental selectivity is obtained because the core levels of different elements are well separated in energy, meaning that the involvement of the inner level makes this probe localized to one specific atomic site around which the electronic structure is reflected as a partial density-of-states contribution. The participation of valence electrons gives the method chemical state sensitivity and further, the dipole nature of the transitions gives particular symmetry information. The new generation synchrotron radiation sources producing intensive tunable monochromatized soft X-ray beams have opened up new possibilities for soft X-ray spectroscopy. The introduction of selectively excited soft X-ray emission has opened a new field of study by disclosing many new possibilities of soft X-ray resonant inelastic scattering. In this paper, some recent findings regarding soft X-ray absorption and emission studies of various nanostructured systems are presented.

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

    E-Print Network [OSTI]

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

    2008-02-11T23:59:59.000Z

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

  17. SMB, X-ray Emission Spectroscopy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiation Protection245C Unlimited ReleaseWelcome to theAbsorption Spectroscopy

  18. High-resolution X-ray spectroscopy of Theta Car

    E-Print Network [OSTI]

    Yael Naze; Gregor Rauw

    2008-08-25T23:59:59.000Z

    Context : The peculiar hot star Theta Car in the open cluster IC2602 is a blue straggler as well as a single-line binary of short period (2.2d). Aims : Its high-energy properties are not well known, though X-rays can provide useful constraints on the energetic processes at work in binaries as well as in peculiar, single objects. Methods : We present the analysis of a 50ks exposure taken with the XMM-Newton observatory. It provides medium as well as high-resolution spectroscopy. Results : Our high-resolution spectroscopy analysis reveals a very soft spectrum with multiple temperature components (1--6MK) and an X-ray flux slightly below the `canonical' value (log[L_X(0.1-10.)/L_{BOL}] ~ -7). The X-ray lines appear surprisingly narrow and unshifted, reminiscent of those of beta Cru and tau Sco. Their relative intensities confirm the anomalous abundances detected in the optical domain (C strongly depleted, N strongly enriched, O slightly depleted). In addition, the X-ray data favor a slight depletion in neon and iron, but they are less conclusive for the magnesium abundance (solar-like?). While no significant changes occur during the XMM-Newton observation, variability in the X-ray domain is detected on the long-term range. The formation radius of the X-ray emission is loosely constrained to <5 R_sol, which allows for a range of models (wind-shock, corona, magnetic confinement,...) though not all of them can be reconciled with the softness of the spectrum and the narrowness of the lines.

  19. Simulating Ru L3-edge X-ray Absorption Spectroscopy with Time...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ru L3-edge X-ray Absorption Spectroscopy with Time-Dependent Density Functional Theory: Model Complexes and Electron Simulating Ru L3-edge X-ray Absorption Spectroscopy with...

  20. X-ray spectroscopy of neutron star low-mass X-ray binaries

    E-Print Network [OSTI]

    Krauss, Miriam Ilana

    2007-01-01T23:59:59.000Z

    In this thesis, I present work spanning a variety of topics relating to neutron star lowmass X-ray binaries (LMXBs) and utilize spectral information from X-ray observations to further our understanding of these sources. ...

  1. Dissimilar behavior of technetium and rhenium in borosilicate waste glass as determined by X-ray absorption spectroscopy

    E-Print Network [OSTI]

    Lukens, Wayne W.; McKeown, David A.; Buechele, Andrew C.; Muller, Isabelle S.; Shuh, David K.; Pegg, Ian L.

    2006-01-01T23:59:59.000Z

    by X-ray fluorescence (XRF) spectroscopy with a relativeuncertainty of 4%. XRF analyses utilized an ARL 9400X-ray fluorescence spectrometer with XRF composition values

  2. Ultrafast X-Ray Spectroscopy as a Probe of Nonequilibrium Dynamics...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    dynamic broadenings, and changes in the branching ratio. The authors demonstrate that ultrafast x-ray spectroscopy is a suitable probe to deliver detailed new insights or...

  3. Growth kinetics of CaF[sub 2]/Si(111) heteroepitaxy: An x-ray photoelectron diffraction study

    SciTech Connect (OSTI)

    Denlinger, J.D.; Rotenberg, E. (Department of Physics and Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720 (United States)); Hessinger, U.; Leskovar, M.; Olmstead, M.A. (Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States))

    1995-02-15T23:59:59.000Z

    Kinetic variations of the initial stages of CaF[sub 2] growth on Si(111) by molecular-beam epitaxy are studied with the [ital in] [ital situ] combination of x-ray photoelectron spectroscopy and diffraction. After the formation of a chemically reacted interface layer, the morphology of the subsequent bulk layers is found to be dependent on the substrate temperature and incident flux rate, as well as the initial interface structure. For substrate temperatures above [similar to]600 [degree]C, subsequent layers do not easily wet the interface layer, and a transition is observed from a three-dimensional island formation at low flux to a laminar growth following the coalescence of bilayer islands at higher flux. At lower substrate temperatures ([similar to]450 [degree]C), a different stoichiometry and structure of the interface layer leads to laminar growth at all fluxes, but with a different bulk nucleation behavior. Crystalline heteroepitaxy is not observed when growth initiates at room temperature, but homoepitaxy does proceed at room temperature if the first few layers are deposited at a high temperature. The different growth regimes are discussed in terms of a kinetic model separating step and terrace nucleation where, contrary to homoepitaxy, step nucleation leads to islanded growth.

  4. High Resolution and Low-Temperature Photoelectron Spectroscopy...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    High Resolution and Low-Temperature Photoelectron Spectroscopy of an Oxygen-Linked Fullerene Dimer Dianion: C120O2-. High Resolution and Low-Temperature Photoelectron Spectroscopy...

  5. Development of a Low-Temperature Photoelectron Spectroscopy Instrument...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Low-Temperature Photoelectron Spectroscopy Instrument Using an Electrospray Ion Source and a Cryogenically Development of a Low-Temperature Photoelectron Spectroscopy Instrument...

  6. Self-detection of x-ray Fresnel transmittivity using photoelectron-induced gas ionization

    E-Print Network [OSTI]

    Stoupin, Stanislav

    2015-01-01T23:59:59.000Z

    Electric response of an x-ray mirror enclosed in a gas flow ionization chamber was studied under the conditions of total external reflection for hard x-rays. It is shown that the electric response of the system as a function of the incidence angle is defined by x-ray Fresnel transmittivity and photon-electron attenuation properties of the mirror material. A simple interpretation of quantum yield of the system is presented. The approach provides non-invasive in-situ diagnostics of hard x-ray optics, easy access to complementary x-ray transmittivity data in x-ray reflectivity experiments and can also pave the way to novel schemes for angle and energy resolving x-ray detectors.

  7. Chandra High Resolution X-ray Spectroscopy of AM Her

    E-Print Network [OSTI]

    V. Girish; V. R. Rana; K. P. Singh

    2007-02-14T23:59:59.000Z

    We present the results of high resolution spectroscopy of the prototype polar AM Herculis observed with Chandra High Energy Transmission Grating. The X-ray spectrum contains hydrogen-like and helium-like lines of Fe, S, Si, Mg, Ne and O with several Fe L-shell emission lines. The forbidden lines in the spectrum are generally weak whereas the hydrogen-like lines are stronger suggesting that emission from a multi-temperature, collisionally ionized plasma dominates. The helium-like line flux ratios yield a plasma temperature of 2 MK and a plasma density 1 - 9 x10^12 cm^-3, whereas the line flux ratio of Fe XXVI to Fe XXV gives an ionization temperature of 12.4 +1.1 -1.4 keV. We present the differential emission measure distribution of AM Her whose shape is consistent with the volume emission measure obtained by multi-temperature APEC model. The multi-temperature plasma model fit to the average X-ray spectrum indicates the mass of the white dwarf to be ~1.15 M_sun. From phase resolved spectroscopy, we find the line centers of Mg XII, S XVI, resonance line of Fe XXV, and Fe XXVI emission modulated by a few hundred to 1000 km/s from the theoretically expected values indicating bulk motion of ionized matter in the accretion column of AM Her. The observed velocities of Fe XXVI ions are close to the expected shock velocity for a 0.6 M_sun white dwarf. The observed velocity modulation is consistent with that expected from a single pole accreting binary system.

  8. Ternary chalcogenide-based photoelectrochemical cells V. Surface analyses of the CuInX/sub 2//aqueous polysulfide interface (X = S, Se) by X-Ray photoelectron spectroscopy; absence of Se/S exchange in the CuInSe/sub 2//S /SUB n/ = system

    SciTech Connect (OSTI)

    Mirovsky, Y.; Cahen, D.; Polak, M.; Sawatzky, G.; Tenner, R.

    1985-05-01T23:59:59.000Z

    n-CuInS/sub 2/ and n-CuInSe/sub 2/ were subjected to surface analyses by x-ray photoelectron and Auger electron spectroscopy, after their use as photoanodes in polysulfide solutions. For CuInS/sub 2/ samples that had a poor (ca. 2%) conversion efficiency, a rather heterogeneous surface was found, with patches rich in In, which is probably present mainly as oxide. Some CuO was found as well, although the top layer was depleted in Cu, compared to a reference sample. More efficient (ca. 5%) samples showed a more homogeneous surface and even stronger Cu depletion. These changes are ascribed to additional surface treatments, viz., dipping in hot KCN solution and thermal oxidation o the resultant etched surface. For CuInSe/sub 2/ samples, no significant exchange of lattice Se by S from the polysulfide solution is seen, in sharp contrast to what is observed for CdSe or CdIn/sub 2/Se/sub 4/. If sulfur is found, its presence could be correlated with the spurious occurrence of Cd (used as dopant) or Ag (used for the ohmic back contact). Cu depletion also occur near the surface of the diselenide after use in polysulfide solution. Most of the remaining In seems to occur in indiu oxide and/or indium selenide. Cu/sub 2/ was found neither here nor on the surface of the more efficient disulfide sample. It is suggested that the occurrence of an indium oxide top layer, aided by thermal oxidation of the electrode in the case o CuInSe/sub 2/, has a beneficial effect on electrode performance.

  9. Negative Ion Photoelectron Spectroscopy Confirms the Prediction...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Confirms the Prediction that (CO)5 and (CO)6 Each Has a Singlet Ground State. Negative Ion Photoelectron Spectroscopy Confirms the Prediction that (CO)5 and (CO)6 Each Has a...

  10. Nuclear resonant inelastic X-ray scattering and synchrotron Mossbauer spectroscopy

    E-Print Network [OSTI]

    Lin, Jung-Fu "Afu"

    Chapter 19 Nuclear resonant inelastic X-ray scattering and synchrotron Mo¨ssbauer spectroscopy with nuclear resonant inelastic X-ray scattering and synchrotron Mo¨ssbauer spectroscopy for studying magnetic to the Planck radiation function. Synchrotron Mo¨ssbauer spectra and partial phonon density of states (PDOS

  11. Ambient Pressure Photoelectron Spectroscopy Using Soft X-ray...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    by scientific communities as an important in-situ tool to study water, environmental science, catalysis and many other important fields. There is perhaps no better...

  12. X-Ray Photoelectron Spectroscopy XPS Mark Engelhard

    E-Print Network [OSTI]

    in the mid-1960s by Kai Siegbahn and his research group at the University of Uppsala, Sweden. The technique

  13. ON THE USE OF EXTENDED X-RAY ABSORPTION FINE STRUCTURE SPECTROSCOPY TO DETERMINE THE BONDING CONFIGURATIONS OF

    E-Print Network [OSTI]

    Sparks, Donald L.

    ON THE USE OF EXTENDED X-RAY ABSORPTION FINE STRUCTURE SPECTROSCOPY TO DETERMINE THE BONDING Rights Reserved #12;ON THE USE OF EXTENDED X-RAY ABSORPTION FINE STRUCTURE SPECTROSCOPY TO DETERMINE

  14. Beam damage of poly(vinyl chloride) [PVC] as observed by x-ray...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    damage of poly(vinyl chloride) PVC as observed by x-ray photoelectron spectroscopy at 143 K, 303 K and 373 K. Beam damage of poly(vinyl chloride) PVC as observed by x-ray...

  15. ambient-pressure x-ray photoelectron: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    are placed to face the fan-beam plane and directly measure x-ray fluorescence data. Detector elements are so collimated that each element only sees a unique area element on...

  16. X-ray Absorption Spectroscopy of Transition Metal-Magnesium Hydride Thin Films

    E-Print Network [OSTI]

    X-ray Absorption Spectroscopy of Transition Metal-Magnesium Hydride Thin Films T. J. Richardsona@lbl.gov Abstract Mixed metal thin films containing magnesium and a first-row transition element exhibit very large of magnesium hydride. Keywords: A. hydrogen storage materials, thin films; C. EXAFS, NEXAFS, X-ray diffraction

  17. Variable growth modes of CaF[sub 2] on Si(111) determined by x-ray photoelectron diffraction

    SciTech Connect (OSTI)

    Denlinger, J.D.; Rotenberg, E. (Department of Physics, University of California, Berkeley, California 94720 (United States) Materials Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States)); Hessinger, U.; Leskovar, M. (Department of Physics FM-15, University of Washington, Seattle, Washington 98195 (United States)); Olmstead, M.A. (Department of Physics FM-15, University of Washington, Seattle, Washington 98195 (United States) Materials Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States))

    1993-04-26T23:59:59.000Z

    Chemical discrimination of bulk and interface Ca 2[ital p] x-ray photoelectron diffraction modulations is used to identify three growth regimes during the initial stages of CaF[sub 2] epitaxy on Si(111). Low flux, high temperature conditions produce island growth atop a nonwetting, chemically reacted Ca-F interface layer. Changing the growth kinetics by increasing the flux produces more laminar growth. Lowering the substrate temperature produces a more stoichiometric CaF[sub 2] interface layer that results in immediate wetting and laminar growth.

  18. Structural investigation on Ge{sub x}Sb{sub 10}Se{sub 90?x} glasses using x-ray photoelectron spectra

    SciTech Connect (OSTI)

    Wei, Wen-Hou [Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Department of Applied Physics, Chongqing University, Chongqing 401331 (China); Xiang, Shen [College of Information Science and Engineering, Ningbo University, Ningbo 315211 (China); Xu, Si-Wei; Wang, Rong-Ping, E-mail: rongping.wang@anu.edu.au [Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Fang, Liang [Department of Applied Physics, Chongqing University, Chongqing 401331 (China)

    2014-05-14T23:59:59.000Z

    The structure of Ge{sub x}Sb{sub 10}Se{sub 90?x} glasses (x?=?7.5, 10, 15, 20, 25, 27.5, 30, and 32.5 at. %) has been investigated by x-ray photoelectron spectroscopy (XPS). Different structural units have been extracted and characterized by decomposing XPS core level spectra, the evolution of the relative concentration of each structural unit indicates that, the relative contributions of Se-trimers and Se-Se-Ge(Sb) structure decrease with increasing Ge content until they become zero at chemically stoichiometric glasses of Ge{sub 25}Sb{sub 10}Se{sub 65}, and then the homopolar bonds like Ge-Ge and Sb-Sb begin to appear in the spectra. Increase of homopolar bonds will extend band-tails into the gap and narrow the optical band gap. Thus, the glass with a stoichiometric composition generally has fewer defective bonds and larger optical bandgap.

  19. HIGH-RESOLUTION X-RAY SPECTROSCOPY OF THE MULTIPHASE INTERSTELLAR MEDIUM TOWARD Cyg X-2

    E-Print Network [OSTI]

    Schulz, Norbert S.

    High-resolution X-ray absorption spectroscopy is a powerful diagnostic tool for probing chemical and physical properties of the interstellar medium (ISM) at various phases. We present detections of K transition absorption ...

  20. Precision X-ray spectroscopy of 3C 273 jet knots

    E-Print Network [OSTI]

    Avara, Mark J

    2008-01-01T23:59:59.000Z

    We present results from precision X-ray spectroscopy using high-resolution ([delta lambda] = 0.01A) spectra of 3C 273 jet knots extracted from eight observations made using Chandra in conjunction with the HETGS. Using these ...

  1. Soft x-ray emission spectroscopy studies of the electronic structure of silicon supersaturated with sulfur

    E-Print Network [OSTI]

    Sullivan, Joseph Timothy

    We apply soft x-ray emission spectroscopy (XES) to measure the electronic structure of crystalline silicon supersaturated with sulfur (up to 0.7 at. %), a candidate intermediate-band solar cell material. Si L[subscript ...

  2. JOURNAL DE PHYSIQUE Colloque C4, supplkment au no 5, Tome 35, Mai 1974,page C4-65 SOFT X-RAY EMISSION AND X-RAY PHOTOELECTRON STUDIES OF

    E-Print Network [OSTI]

    Boyer, Edmond

    -RAY EMISSION AND X-RAY PHOTOELECTRON STUDIES OF DISORDERED ALUMINIUM ALLOYS IN RELATION TO CPA THEORY P. R). Measurementsfor alloy solid solutions of aluminium with the noble metal silver and the transi- tion metal vanadium'6tat solide d'aluminium avec un metal prtcieux, l'argent et un metal de transition, le vanadium. L

  3. N-derived signals in the x-ray photoelectron spectra of N-doped anatase TiO{sub 2}

    SciTech Connect (OSTI)

    Yu, Y. P. [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Department of Physics, Shantou University, Shantou 515063 (China); Xing, X. J.; Xu, L. M.; Wu, S. X.; Li, S. W. [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

    2009-06-15T23:59:59.000Z

    The plasma-assisted molecular beam epitaxial anatase TiO{sub 2-x}N{sub x} (x<0.3) films were chosen to investigate the N-derived variation in the x-ray photoelectron spectroscopy (XPS). With increasing nitrogen concentration, the small chemical shift and the shoulder of the main peak emerge in the N 1s, O 1s, or Ti 2p{sub 3/2} core level spectra. In combination with the experimental results obtained from x-ray diffraction and atomic force microscopy, the variations in the spectra could be ascribed to the microstructural distortion. This distortion, induced by the N{sup 3-} substitution for lattice O{sup 2-}, could slightly decrease the average ionicity of the Ti-O (or N) bonds. In addition, the other N 1s features (at 399.8 and 401.8 eV) and the oxygen vacancy are also discussed. For the N-doped TiO{sub 2}, this work introduces a correlation between the microstructural properties and the XPS signals.

  4. Anion photoelectron spectroscopy of radicals and clusters

    SciTech Connect (OSTI)

    Travis, Taylor R.

    1999-12-16T23:59:59.000Z

    Anion photoelectron spectroscopy is used to study free radicals and clusters. The low-lying {sup 2}{Sigma} and {sup 2}{Pi} states of C{sub 2n}H (n = 1--4) have been studied. The anion photoelectron spectra yielded electron affinities, term values, and vibrational frequencies for these combustion and astrophysically relevant species. Photoelectron angular distributions allowed the author to correctly assign the electronic symmetry of the ground and first excited states and to assess the degree of vibronic coupling in C{sub 2}H and C{sub 4}H. Other radicals studied include NCN and I{sub 3}. The author was able to observe the low-lying singlet and triplet states of NCN for the first time. Measurement of the electron affinity of I{sub 3} revealed that it has a bound ground state and attachment of an argon atom to this moiety enabled him to resolve the symmetric stretching progression.

  5. Temperature-Dependent Photoelectron Spectroscopy of Methyl-Benzoate...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Spectroscopy of Methyl-Benzoate Anions: Observation of Steric Effect in Ortho-Methyl Temperature-Dependent Photoelectron Spectroscopy of Methyl-Benzoate Anions: Observation of...

  6. Dynamics in shear flow studied by X-ray Photon Correlation Spectroscopy

    E-Print Network [OSTI]

    Sebastian Busch; Torben Haugaard Jensen; Yuriy Chushkin; Andrei Fluerasu

    2008-03-19T23:59:59.000Z

    X-ray photon correlation spectroscopy was used to measure the diffusive dynamics of colloidal particles in a shear flow. The results presented here show how the intensity autocorrelation functions measure both the diffusive dynamics of the particles and their flow-induced, convective motion. However, in the limit of low flow/shear rates, it is possible to obtain the diffusive component of the dynamics, which makes the method suitable for the study of the dynamical properties of a large class of complex soft-matter and biological fluids. An important benefit of this experimental strategy over more traditional X-ray methods is the minimization of X-ray induced beam damage. While the method can be applied also for photon correlation spectroscopy in the visible domain, our analysis shows that the experimental conditions under which it is possible to measure the diffusive dynamics are easier to achieve at higher q values (with X-rays).

  7. Observation of Strong Resonant Behavior in the Inverse Photoelectron Spectroscopy of Ce Oxide

    SciTech Connect (OSTI)

    Tobin, J G; Yu, S W; Chung, B W; Waddill, G D; Damian, E; Duda, L; Nordgren, J

    2009-12-15T23:59:59.000Z

    X-ray Emission Spectroscopy (XES) and Resonant Inverse Photoelectron Spectroscopy (RIPES) have been used to investigate the photon emission associated with the Ce3d5/2 and Ce3d3/2 thresholds. Strong resonant behavior has been observed in the RIPES of Ce Oxide near the 5/2 and 3/2 edges. Inverse Photoelectron Spectroscopy (IPES) and its high energy variant, Bremstrahlung Isochromat Spectroscopy (BIS), are powerful techniques that permit a direct interrogation of the low-lying unoccupied electronic structure of a variety of materials. Despite being handicapped by counting rates that are approximately four orders of magnitude less that the corresponding electron spectroscopies (Photoelectron Spectroscopy, PES, and X-ray Photoelectron Spectroscopy, XPS) both IPES and BIS have a long history of important contributions. Over time, an additional variant of this technique has appeared, where the kinetic energy (KE) of the incoming electron and photon energy (hv) of the emitted electron are roughly the same magnitude as the binding energy of a core level of the material in question. Under these circumstances and in analogy to Resonant Photoelectron Spectroscopy, a cross section resonance can occur, giving rise to Resonant Inverse Photoelectron Spectroscopy or RIPES. Here, we report the observation of RIPES in an f electron system, specifically the at the 3d{sub 5/2} and 3d{sub 3/2} thresholds of Ce Oxide. The resonant behavior of the Ce4f structure at the 3d thresholds has been addressed before, including studies of the utilization of the technique as a probe of electron correlation in a variety of Ce compounds. Interestingly, the first RIPES work on rare earths dates back to 1974, although under conditions which left the state of the surface and near surface regions undefined. Although they did not use the more modern terminology of 'RIPES,' it is clear that RIPES was actually first performed in 1974 by Liefeld, Burr and Chamberlain on both La and Ce based materials. In these experiments, the La and Ce metallic samples were attached to the anode of an x-ray tube and the x-ray emission characteristics were measured using a two crystal monochromator. The pressure in the x-ray tube was quoted as being below 2 x 10{sup -8} Torr. They did indeed observed resonant behavior at the M{alpha} (3d{sub 5/2}) and M{beta} (3d{sub 3/2}) thresholds. In fact, our results here will confirm the measurements made upon the Ce based sample used in by Liefeld et al. However, the state of the Ce sample surface and near surface regions are quite undefined in the study in Ref 9. For example, the authors suggest that they are probing Ce metal, since they cannot see any evidence of an OK{alpha} (1s) XES line. However, they do report the observation of FK{alpha} (1s) line, possibly due to the utilization of cerium fluoride in the sample preparation. Later, they tried to address these issues in a new ultrahigh vacuum system. Based upon our results, it is clear that their original sample surface was oxidized, using the word here in its more general context as in having lost electrons to the oxidizing agent, although whether the structure is an oxide or fluoride remains unclear. In any case, the primacy of Liefeld and coworkers in these measurements should be noted. Cerium and cerium oxide have been studied with a variety of spectroscopic techniques under UHV conditions. This includes Bremstrahlung Isochromat Spectroscopy or BIS, Photoelectron Spectroscopy, X-ray Absorption Spectroscopy, Electron Energy Loss Spectroscopy and Resonant XES, to name just a few. We will compare our results to those of other spectroscopies.

  8. Note: Application of a pixel-array area detector to simultaneous single crystal x-ray diffraction and x-ray absorption spectroscopy measurements

    SciTech Connect (OSTI)

    Sun, Cheng-Jun, E-mail: cjsun@aps.anl.gov; Brewe, Dale L.; Heald, Steve M. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)] [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Zhang, Bangmin [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States) [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Materials Science and Engineering, National University of Singapore, 117575 Singapore (Singapore); NUSNNI-Nanocore, National University of Singapore, 117411 Singapore (Singapore); Chen, Jing-Sheng; Chow, G. M. [Department of Materials Science and Engineering, National University of Singapore, 117575 Singapore (Singapore)] [Department of Materials Science and Engineering, National University of Singapore, 117575 Singapore (Singapore); Venkatesan, T. [NUSNNI-Nanocore, National University of Singapore, 117411 Singapore (Singapore) [NUSNNI-Nanocore, National University of Singapore, 117411 Singapore (Singapore); Department of Physics, National University of Singapore, 117542 Singapore (Singapore); Department of Electrical and Computer Engineering, National University of Singapore, 117575 Singapore (Singapore)

    2014-04-15T23:59:59.000Z

    X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) are two main x-ray techniques in synchrotron radiation facilities. In this Note, we present an experimental setup capable of performing simultaneous XRD and XAS measurements by the application of a pixel-array area detector. For XRD, the momentum transfer in specular diffraction was measured by scanning the X-ray energy with fixed incoming and outgoing x-ray angles. By selecting a small fixed region of the detector to collect the XRD signal, the rest of the area was available for collecting the x-ray fluorescence for XAS measurements. The simultaneous measurement of XRD and X-ray absorption near edge structure for Pr{sub 0.67}Sr{sub 0.33}MnO{sub 3} film was demonstrated as a proof of principle for future time-resolved pump-probe measurements. A static sample makes it easy to maintain an accurate overlap of the X-ray spot and laser pump beam.

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

    SciTech Connect (OSTI)

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

    2014-01-15T23:59:59.000Z

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

  10. Ultrafast conversions between hydrogen bonded structures in liquid water observed by femtosecond x-ray spectroscopy

    SciTech Connect (OSTI)

    Wen, Haidan; Huse, Nils; Schoenlein, Robert W.; Lindenberg, Aaron M.

    2010-05-01T23:59:59.000Z

    We present the first femtosecond soft x-ray spectroscopy in liquids, enabling the observation of changes in hydrogen bond structures in water via core-hole excitation. The oxygen K-edge of vibrationally excited water is probed with femtosecond soft x-ray pulses, exploiting the relation between different water structures and distinct x-ray spectral features. After excitation of the intramolecular OH stretching vibration, characteristic x-ray absorption changes monitor the conversion of strongly hydrogen-bonded water structures to more disordered structures with weaker hydrogen-bonding described by a single subpicosecond time constant. The latter describes the thermalization time of vibrational excitations and defines the characteristic maximum rate with which nonequilibrium populations of more strongly hydrogen-bonded water structures convert to less-bonded ones. On short time scales, the relaxation of vibrational excitations leads to a transient high-pressure state and a transient absorption spectrum different from that of statically heated water.

  11. X-ray spectroscopy of the supernova remnant RCW 86

    E-Print Network [OSTI]

    Jacco Vink; Jelle Kaastra; Johan Bleeker

    1997-09-12T23:59:59.000Z

    We present an analysis of ASCA X-ray data of SNR RCW 86. There appears to be a remarkable spectral variation over the remnant, indicating temperatures varying from 0.8 keV to > 3 keV. We have fitted these spectra with non-equilibrium ionization models and found that all regions are best fitted by emission from a hot plasma underabundant in metals (<0.25 solar), but in some cases fluorescent emission indicates overabundances of Ar and Fe. The ionization stage of the metals appears to be far from equilibrium, at some spots as low as log(n_e t) 15.3 (SI units). We discuss the physical reality of the abundances and suggest an electron distribution with a supra-thermal tail to alleviate the strong depletion factors observed. We argue that RCW 86 is the result of a cavity explosion.

  12. X-ray Spectroscopy for Quality Control of Chemotherapy Drugs

    SciTech Connect (OSTI)

    Greaves, E. D.; Barros, H.; Bermudez, J.; Sajo-Bohus, L. [Universidad Simon Bolivar, Apartado 89000, Caracas 1080A (Venezuela); Angeli-Greaves, M. [Universidad Central de Venezuela, Apartado 90373 Caracas 1083A (Venezuela)

    2007-10-26T23:59:59.000Z

    We develop a method, employing Compton peak standardization and the use of matrix-matched spiked samples with Total Reflection X-ray Fluorescence (TXRF), for the determination of platinum plasma concentrations of patients undergoing chemotherapy with Pt-bearing drugs. Direct blood plasma analysis attains Pt detection limits of 70 ng/ml. Measurement results of prescribed drug doses are compared to achieved blood Pt concentrations indicating a lack of expected correlations. Direct analysis of Pt-containing infused drugs from a variety of suppliers indicates cases of abnormal concentrations which raises quality control issues. We demonstrate the potential usefulness of the method for pharmacokinetic studies or for routine optimization and quality control of Pt chemotherapy treatments.

  13. Mode-Locked Multichromatic X-Rays in a Seeded Free-Electron Laser for Single-Shot X-Ray Spectroscopy

    SciTech Connect (OSTI)

    Xiang, Dao; Ding, Yuantao; Raubenheimer, Tor; Wu, Juhao; /SLAC

    2012-05-10T23:59:59.000Z

    We present the promise of generating gigawatt mode-locked multichromatic x rays in a seeded free-electron laser (FEL). We show that, by using a laser to imprint periodic modulation in electron beam phase space, a single-frequency coherent seed can be amplified and further translated to a mode-locked multichromatic output in an FEL. With this configuration the FEL output consists of a train of mode-locked ultrashort pulses which span a wide frequency gap with a series of equally spaced sharp lines. These gigawatt multichromatic x rays may potentially allow one to explore the structure and dynamics of a large number of atomic states simultaneously. The feasibility of generating mode-locked x rays ranging from carbon K edge ({approx}284 eV) to copper L{sub 3} edge ({approx}931 eV) is confirmed with numerical simulation using the realistic parameters of the linac coherent light source (LCLS) and LCLS-II. We anticipate that the mode-locked multichromatic x rays in FELs may open up new opportunities in x-ray spectroscopy (i.e. resonant inelastic x-ray scattering, time-resolved scattering and spectroscopy, etc.).

  14. In Situ Synchrotron X-ray Spectroscopy of Lanthanum Manganite Solid Oxide Fuel Cell Electrodes

    E-Print Network [OSTI]

    Yildiz, Bilge

    . Introduction The solid oxide fuel cell (SOFC) has potential to produce energy with high efficiency, especiallyIn Situ Synchrotron X-ray Spectroscopy of Lanthanum Manganite Solid Oxide Fuel Cell Electrodes Kee fuel cells (SOFC) under long term cathodic or anodic polarization, termed `current conditioning

  15. X-ray absorption spectroscopy of biomimetic dye molecules for solar cells Peter L. Cook,1

    E-Print Network [OSTI]

    Himpsel, Franz J.

    X-ray absorption spectroscopy of biomimetic dye molecules for solar cells Peter L. Cook,1 Xiaosong November 2009 Dye-sensitized solar cells are potentially inexpensive alternatives to traditional semiconductor solar cells. In order to optimize dyes for solar cells we systematically investigate

  16. Science Highlight March 2010 Schematic drawing of the setup for x-ray emission spectroscopy

    E-Print Network [OSTI]

    Wechsler, Risa H.

    foodstuffs for nutrition while recycling CO2 from the atmosphere and replacing it with O2. By utilizingScience Highlight ­ March 2010 Schematic drawing of the setup for x-ray emission spectroscopy of complex aerobic life. Coupled to the reduction of carbon dioxide, biological photosynthesis contrib- utes

  17. HIV-1 Tat membrane interactions probed using X-ray and neutron scattering, CD spectroscopy and MD simulations

    E-Print Network [OSTI]

    Nagle, John F.

    HIV-1 Tat membrane interactions probed using X-ray and neutron scattering, CD spectroscopy and MD translocation, were provided by wide-angle X-ray scattering (WAXS) and neutron scattering. CD spectroscopy for Neutron Research, 100 Bureau Drive, Stop 6102, Gaithersburg, MD 20899, United States d CHESS, Cornell

  18. Two-dimensional stimulated resonance Raman spectroscopy of molecules with broadband x-ray pulses

    SciTech Connect (OSTI)

    Biggs, Jason D.; Zhang Yu; Healion, Daniel; Mukamel, Shaul [Department of Chemistry, University of California, Irvine, California 92697-2025 (United States)

    2012-05-07T23:59:59.000Z

    Expressions for the two-dimensional stimulated x-ray Raman spectroscopy (2D-SXRS) signal obtained using attosecond x-ray pulses are derived. The 1D- and 2D-SXRS signals are calculated for trans-N-methyl acetamide (NMA) with broad bandwidth (181 as, 14.2 eV FWHM) pulses tuned to the oxygen and nitrogen K-edges. Crosspeaks in 2D signals reveal electronic Franck-Condon overlaps between valence orbitals and relaxed orbitals in the presence of the core-hole.

  19. The growth of epitaxial iron oxides on platinum (111) as studied by X-ray photoelectron diffraction, scanning tunneling microscopy, and low energy electron diffraction

    SciTech Connect (OSTI)

    Kim, Y.J.

    1995-05-01T23:59:59.000Z

    Three complementary surface structure probes, x-ray photoelectron diffraction (XPD), scanning tunneling microscopy (STM), and low-energy electron diffraction (LEED) have been combined in a single instrument. This experimental system has been utilized to study the structure and growth mechanisms of iron oxide films on Pt(111); these films were formed by first depositing a single overlayer of Fe with a certain coverage in monolayers (ML`s), and then thermally oxidizing it in an oxygen atmosphere. For films up to {approximately}1 ML in thickness, a bilayer of Fe and O similar to those in FeO(111) is found to form. In agreement with prior studies, STM and LEED show this to be an incommensurate oxide film forming a lateral superlattice with short- and long-range periodicities of {approximately}3.1 {Angstrom} and {approximately}26.0 {Angstrom}. XPD in addition shows a topmost oxygen layer to be relaxed inward by -0.6 {Angstrom} compared to bulk FeO(111), and these are new structural conclusions. The oxygen stacking in the FeO(111) bilayer is dominated by one of two possible binding sites. For thicker iron oxide films from 1.25 ML to 3.0 ML, the growth mode is essentially Stranski-Krastanov: iron oxide islands form on top of the FeO(111) bilayer mentioned above. For iron oxide films of 3.0 ML thickness, x-ray photoelectron spectroscopy (XPS) yields an Fe 2p{sub 3/2} binding energy and an Fe:O stoichiometry consistent with the presence of Fe{sub 3}O{sub 4}. Our XPD data further prove this overlayer to be Fe{sub 3}O{sub 4}(111)-magnetite in two almost equally populated domains with a 180{degrees} rotation between them. The structural parameters for this Fe{sub 3}O{sub 4} overlayer generally agree with those of a previous LEED study, except that we find a significant difference in the first Fe-O interplanar spacing. This work demonstrates the considerable benefits to be derived by using this set of complementary surface structure probes in such epitaxial growth studies.

  20. Gas cell for in situ soft X-ray transmission-absorption spectroscopy of materials

    SciTech Connect (OSTI)

    Drisdell, W. S.; Kortright, J. B. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2014-07-15T23:59:59.000Z

    A simple gas cell design, constructed primarily from commercially available components, enables in situ soft X-ray transmission-absorption spectroscopy of materials in contact with gas at ambient temperature. The cell has a minimum X-ray path length of 1 mm and can hold gas pressures up to ?300 Torr, and could support higher pressures with simple modifications. The design enables cycling between vacuum and gas environments without interrupting the X-ray beam, and can be fully sealed to allow for measurements of air-sensitive samples. The cell can attach to the downstream port of any appropriate synchrotron beamline, and offers a robust and versatile method for in situ measurements of certain materials. The construction and operation of the cell are discussed, as well as sample preparation and proper spectral analysis, illustrated by examples of spectral measurements. Potential areas for improvement and modification for specialized applications are also mentioned.

  1. SURFACE SEGREGATION STUDIES OF SOFC CATHODES: COMBINING SOFT X-RAYS AND ELECTROCHEMICAL IMPEDENCE SPECTROSCOPY

    SciTech Connect (OSTI)

    Miara, Lincoln J.; Piper, L.F.J.; Davis, Jacob N.; Saraf, Laxmikant V.; Kaspar, Tiffany C.; Basu, Soumendra; Smith, K. E.; Pal, Uday B.; Gopalan, Srikanth

    2010-12-01T23:59:59.000Z

    A system to grow heteroepitaxial thin-films of solid oxide fuel cell (SOFC) cathodes on single crystal substrates was developed. The cathode composition investigated was 20% strontium-doped lanthanum manganite (LSM) grown by pulsed laser deposition (PLD) on single crystal (111) yttria-stabilized zirconia (YSZ) substrates. By combining electrochemical impedance spectroscopy (EIS) with x-ray photoemission spectroscopy (XPS) and x-ray absorption spectroscopy XAS measurements, we conclude that electrically driven cation migration away from the two-phase gas-cathode interface results in improved electrochemical performance. Our results provide support to the premise that the removal of surface passivating phases containing Sr2+ and Mn2+, which readily form at elevated temperatures even in O2 atmospheric pressures, is responsible for the improved cathodic performance upon application of a bias.

  2. Bimolecular reaction dynamics from photoelectron spectroscopy of negative ions

    SciTech Connect (OSTI)

    Bradforth, S.E.

    1992-11-01T23:59:59.000Z

    The transition state region of a neutral bimolecular reaction may be experimentally investigated by photoelectron spectroscopy of an appropriate negative ion. The photoelectron spectrum provides information on the spectroscopy and dynamics of the short lived transition state and may be used to develop model potential energy surfaces that are semi-quantitative in this important region. The principles of bound [yields] bound negative ion photoelectron spectroscopy are illustrated by way of an example: a full analysis of the photoelectron bands of CN[sup [minus

  3. ON RELATIVISTIC DISK SPECTROSCOPY IN COMPACT OBJECTS WITH X-RAY CCD CAMERAS

    SciTech Connect (OSTI)

    Miller, J. M.; Cackett, E. M. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); D'Ai, A. [Dipartimento di Scienze Fisiche ed Astronomiche, Universita di Palermo, Palermo (Italy); Bautz, M. W.; Nowak, M. A. [Kavli Institute for Astrophysics and Space Research, MIT, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Bhattacharyya, S. [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Mumbai 400005 (India); Burrows, D. N.; Kennea, J. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, College Park, PA 16802 (United States); Fabian, A. C.; Reis, R. C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 OHA (United Kingdom); Freyberg, M. J.; Haberl, F. [Max-Planck-Institut fuer extraterrestrische Physik, Giessenbachstrasse, 85748 Garching (Germany); Strohmayer, T. E. [Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Tsujimoto, M., E-mail: jonmm@umich.ed [Japan Aerospace Exploration Agency, Institute of Space and Astronomical Sciences, 3-1-1 Yoshino-dai, Sagamihara, Kanagawa 229-8510 (Japan)

    2010-12-01T23:59:59.000Z

    X-ray charge-coupled devices (CCDs) are the workhorse detectors of modern X-ray astronomy. Typically covering the 0.3-10.0 keV energy range, CCDs are able to detect photoelectric absorption edges and K shell lines from most abundant metals. New CCDs also offer resolutions of 30-50 (E/{Delta}E), which is sufficient to detect lines in hot plasmas and to resolve many lines shaped by dynamical processes in accretion flows. The spectral capabilities of X-ray CCDs have been particularly important in detecting relativistic emission lines from the inner disks around accreting neutron stars and black holes. One drawback of X-ray CCDs is that spectra can be distorted by photon 'pile-up', wherein two or more photons may be registered as a single event during one frame time. We have conducted a large number of simulations using a statistical model of photon pile-up to assess its impacts on relativistic disk line and continuum spectra from stellar-mass black holes and neutron stars. The simulations cover the range of current X-ray CCD spectrometers and operational modes typically used to observe neutron stars and black holes in X-ray binaries. Our results suggest that severe photon pile-up acts to falsely narrow emission lines, leading to falsely large disk radii and falsely low spin values. In contrast, our simulations suggest that disk continua affected by severe pile-up are measured to have falsely low flux values, leading to falsely small radii and falsely high spin values. The results of these simulations and existing data appear to suggest that relativistic disk spectroscopy is generally robust against pile-up when this effect is modest.

  4. On Relativistic Disk Spectroscopy in Compact Objects with X-ray CCD Cameras

    E-Print Network [OSTI]

    J. M. Miller; A. D'Ai; M. W. Bautz; S. Bhattacharyya; D. N. Burrows; E. M. Cackett; A. C. Fabian; M. J. Freyberg; F. Haberl; J. Kennea; M. A Nowak; R. C. Reis; T. E. Strohmayer; M. Tsujimoto

    2010-09-22T23:59:59.000Z

    X-ray charge-coupled devices (CCDs) are the workhorse detectors of modern X-ray astronomy. Typically covering the 0.3-10.0 keV energy range, CCDs are able to detect photoelectric absorption edges and K shell lines from most abundant metals. New CCDs also offer resolutions of 30-50 (E/dE), which is sufficient to detect lines in hot plasmas and to resolve many lines shaped by dynamical processes in accretion flows. The spectral capabilities of X-ray CCDs have been particularly important in detecting relativistic emission lines from the inner disks around accreting neutron stars and black holes. One drawback of X-ray CCDs is that spectra can be distorted by photon "pile-up", wherein two or more photons may be registered as a single event during one frame time. We have conducted a large number of simulations using a statistical model of photon pile-up to assess its impacts on relativistic disk line and continuum spectra from stellar-mass black holes and neutron stars. The simulations cover the range of current X-ray CCD spectrometers and operational modes typically used to observe neutron stars and black holes in X-ray binaries. Our results suggest that severe photon pile-up acts to falsely narrow emission lines, leading to falsely large disk radii and falsely low spin values. In contrast, our simulations suggest that disk continua affected by severe pile-up are measured to have falsely low flux values, leading to falsely small radii and falsely high spin values. The results of these simulations and existing data appear to suggest that relativistic disk spectroscopy is generally robust against pile-up when this effect is modest.

  5. Electrochemical flowcell for in-situ investigations by soft x-ray absorption and emission spectroscopy

    SciTech Connect (OSTI)

    Schwanke, C.; Lange, K. M., E-mail: Kathrin.lange@helmholtz-berlin.de [Helmholtz-Zentrum Berlin für Materialien und Energie, Institute of Solar Fuels, Albert-Einstein-Straße 15, 12489 Berlin (Germany); Golnak, R.; Xiao, J. [Helmholtz-Zentrum Berlin für Materialien und Energie, Institute of Methods for Material Development, Albert-Einstein-Straße 15, 12489 Berlin (Germany)

    2014-10-15T23:59:59.000Z

    A new liquid flow-cell designed for electronic structure investigations at the liquid-solid interface by soft X-ray absorption and emission spectroscopy is presented. A thin membrane serves simultaneously as a substrate for the working electrode and solid state samples as well as for separating the liquid from the surrounding vacuum conditions. In combination with counter and reference electrodes this approach allows in-situ studies of electrochemical deposition processes and catalytic reactions at the liquid-solid interface in combination with potentiostatic measurements. As model system in-situ monitoring of the deposition process of Co metal from a 10 mM CoCl{sub 2} aqueous solution by X-ray absorption and emission spectroscopy is presented.

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

    SciTech Connect (OSTI)

    Paesler, M.; Sayers, D.

    1988-12-01T23:59:59.000Z

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

  7. X-ray absorption spectroscopy by full-field X-ray microscopy of a thin graphite flake: Imaging and

    E-Print Network [OSTI]

    Hitchcock, Adam P.

    .bittencourt@ua.ac.be * Corresponding author Keywords: carbon; graphene; nanostructure; NEXAFS; X-ray microscopy Beilstein J structure of graphite flakes consisting of a few graphene layers. The flake was produced by exfoli- ation of the remarkable transport properties of graphene in 2004 by Geim and Novoselov triggered intense interest in its

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

    E-Print Network [OSTI]

    Trichas, Markos

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

  9. Double-core excitations in formamide can be probed by X-ray double-quantum-coherence spectroscopy

    E-Print Network [OSTI]

    Mukamel, Shaul

    Yu Zhang, Daniel Healion, Jason D. Biggs, and Shaul Mukamel Citation: J. Chem. Phys. 138, 144301 be probed by X-ray double-quantum-coherence spectroscopy Yu Zhang, Daniel Healion, Jason D. Biggs, and Shaul

  10. X-ray photon correlation spectroscopy studies of the dynamics of self-assembling block copolymer structures

    E-Print Network [OSTI]

    Falus, Péter, 1972-

    2004-01-01T23:59:59.000Z

    Several improvements presented to the emerging technique of X-ray Photon Correlation Spectroscopy. These improvements enabled the study of polymer structures, in particular isotropic sponge phases of homo-polymer block ...

  11. Use of X-ray Absorption Spectroscopy to Distinguish Between Inner And Outer-sphere Pb Adsorption Complexes on Montmorillonite

    E-Print Network [OSTI]

    Sparks, Donald L.

    Use of X-ray Absorption Spectroscopy to Distinguish Between Inner And Outer-sphere Pb Adsorption on the functional groups at the edges of the montmorillonite. At I = 0.002 M Pb absorption was less dependent

  12. Sample-morphology effects on x-ray photoelectron peak intensities. II. Estimation of detection limits for thin-film materials

    SciTech Connect (OSTI)

    Powell, Cedric J., E-mail: cedric.powell@nist.gov [Materials Measurement Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8370 (United States); Werner, Wolfgang S. M.; Smekal, Werner [Institute of Applied Physics, Technical University of Vienna, Wiedner Hauptstrasse 8-10, A-1040 Vienna (Austria)

    2014-09-01T23:59:59.000Z

    The authors show that the National Institute of Standards and Technology database for the simulation of electron spectra for surface analysis (SESSA) can be used to determine detection limits for thin-film materials such as a thin film on a substrate or buried at varying depths in another material for common x-ray photoelectron spectroscopy (XPS) measurement conditions. Illustrative simulations were made for a W film on or in a Ru matrix and for a Ru film on or in a W matrix. In the former case, the thickness of a W film at a given depth in the Ru matrix was varied so that the intensity of the W 4d{sub 5/2} peak was essentially the same as that for a homogeneous RuW{sub 0.001} alloy. Similarly, the thickness of a Ru film at a selected depth in the W matrix was varied so that the intensity of the Ru 3p{sub 3/2} peak matched that from a homogeneous WRu{sub 0.01} alloy. These film thicknesses correspond to the detection limits of each minor component for measurement conditions where the detection limits for a homogeneous sample varied between 0.1 at.?% (for the RuW{sub 0.001} alloy) and 1 at.?% (for the WRu{sub 0.01} alloy). SESSA can be similarly used to convert estimates of XPS detection limits for a minor species in a homogeneous solid to the corresponding XPS detection limits for that species as a thin film on or buried in the chosen solid.

  13. Electronic Properties of Hydrogen Storage Materials with Photon-in/Photon-out Soft-X-Ray Spectroscopy

    SciTech Connect (OSTI)

    Guo, Jinghua

    2008-09-22T23:59:59.000Z

    The applications of resonant soft X-ray emission spectroscopy on a variety of carbon systems have yielded characteristic fingerprints. With high-resolution monochromatized synchrotron radiation excitation, resonant inelastic X-ray scattering has emerged as a new source of information about electronic structure and excitation dynamics. Photon-in/photon-out soft-X-ray spectroscopy is used to study the electronic properties of fundamental materials, nanostructure, and complex hydrides and will offer potential in-depth understanding of chemisorption and/or physisorption mechanisms of hydrogen adsorption/desorption capacity and kinetics.

  14. GEOC Thursday, March 25, 2010 192 -In situ characterization of environmental redox reactions using quick-scanning X-ray absorption spectroscopy

    E-Print Network [OSTI]

    Sparks, Donald L.

    quick-scanning X-ray absorption spectroscopy (Q-XAS) Donald L Sparks, Dr. Matthew Ginder-Vogel, Dr. In this presentation, we will describe the use of quick X-ray absorption spectroscopy (Q-XAS), at a subsecond time by calculated rate constants that do not change with concentration. In addition to using X-ray absorption near

  15. Photoelectron Spectroscopy and Theoretical Studies of UF5 - and...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Studies of UF5 - and UF6 -. Photoelectron Spectroscopy and Theoretical Studies of UF5 - and UF6 -. Abstract: The UF5 ? and UF6 ? anions are produced using electrospray...

  16. Photoelectron Spectroscopy of Doubly and Singly Charged Group...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Doubly and Singly Charged Group VIB Dimetalate Anions: M2O72-, MM'072-, and M207- (M, M'Cr, Mo, W Photoelectron Spectroscopy of Doubly and Singly Charged Group VIB Dimetalate...

  17. Photoelectron Spectroscopy of Free Multiply Charged Keggin Anions...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Free Multiply Charged Keggin Anions ?-PM12O403- (M Mo, W) in the Gas Phase. Photoelectron Spectroscopy of Free Multiply Charged Keggin Anions ?-PM12O403- (M Mo,...

  18. Use of X-Ray Absorption Spectroscopy to Monitor the Kinetics of Metal Sorption Reactions at the Soil/Water Interface

    E-Print Network [OSTI]

    Sparks, Donald L.

    Use of X-Ray Absorption Spectroscopy to Monitor the Kinetics of Metal Sorption Reactions on the surface coordination environment of Ni sorbed onto clays and aluminum oxides using X-ray absorption fine

  19. How Can X-ray Transient Absorption Spectroscopy Aide Solar Energy...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    are from optimized on structural, energetic and dynamic parameters. Intense X-ray pulses from synchrotrons and X-ray free electrons lasers coupled with ultrafast lasers...

  20. Zero kinetic energy photoelectron spectroscopy of triphenylene

    SciTech Connect (OSTI)

    Harthcock, Colin; Zhang, Jie; Kong, Wei, E-mail: wei.kong@oregonstate.edu [Department of Chemistry, Oregon State University, Corvallis, Oregon 97331 (United States)

    2014-06-28T23:59:59.000Z

    We report vibrational information of both the first electronically excited state and the ground cationic state of jet-cooled triphenylene via the techniques of resonantly enhanced multiphoton ionization (REMPI) and zero kinetic energy (ZEKE) photoelectron spectroscopy. The first excited electronic state S{sub 1} of the neutral molecule is of A{sub 1}? symmetry and is therefore electric dipole forbidden in the D{sub 3h} group. Consequently, there are no observable Franck-Condon allowed totally symmetric a{sub 1}? vibrational bands in the REMPI spectrum. All observed vibrational transitions are due to Herzberg-Teller vibronic coupling to the E? third electronically excited state S{sub 3}. The assignment of all vibrational bands as e? symmetry is based on comparisons with calculations using the time dependent density functional theory and spectroscopic simulations. When an electron is eliminated, the molecular frame undergoes Jahn-Teller distortion, lowering the point group to C{sub 2v} and resulting in two nearly degenerate electronic states of A{sub 2} and B{sub 1} symmetry. Here we follow a crude treatment by assuming that all e? vibrational modes resolve into b{sub 2} and a{sub 1} modes in the C{sub 2v} molecular frame. Some observed ZEKE transitions are tentatively assigned, and the adiabatic ionization threshold is determined to be 63?365 ± 7 cm{sup ?1}. The observed ZEKE spectra contain a consistent pattern, with a cluster of transitions centered near the same vibrational level of the cation as that of the intermediate state, roughly consistent with the propensity rule. However, complete assignment of the detailed vibrational structure due to Jahn-Teller coupling requires much more extensive calculations, which will be performed in the future.

  1. Hard x-ray emission spectroscopy: a powerful tool for the characterization of magnetic semiconductors

    E-Print Network [OSTI]

    Rovezzi, Mauro

    2014-01-01T23:59:59.000Z

    This review aims to introduce the x-ray emission spectroscopy (XES) and resonant inelastic x-ray scattering (RIXS) techniques to the materials scientist working with magnetic semiconductors (e.g. semiconductors doped with 3d transition metals) for applications in the field of spin-electronics. We focus our attention on the hard part of the x-ray spectrum (above 3 keV) in order to demonstrate a powerful element- and orbital-selective characterization tool in the study of bulk electronic structure. XES and RIXS are photon-in/photon-out second order optical processes described by the Kramers-Heisenberg formula. Nowadays, the availability of third generation synchrotron radiation sources permits to apply such techniques also to dilute materials, opening the way for a detailed atomic characterization of impurity-driven materials. We present the K{\\ss} XES as a tool to study the occupied valence states (directly, via valence-to-core transitions) and to probe the local spin angular momentum (indirectly, via intra-at...

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

    SciTech Connect (OSTI)

    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)

    2012-03-13T23:59:59.000Z

    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.

  3. X-ray absorption spectroscopy studies of electrochemically deposited thin oxide films.

    SciTech Connect (OSTI)

    Balasubramanian, M.

    1998-06-02T23:59:59.000Z

    We have utilized ''in situ'' X-ray Absorption Fine Structure Spectroscopy to investigate the structure and composition of thin oxide films of nickel and iron that have been prepared by electrodeposition on a graphite substrate from aqueous solutions. The films are generally disordered. Structural information has been obtained from the analysis of the data. We also present initial findings on the local structure of heavy metal ions, e.g. Sr and Ce, incorporated into the electrodeposited nickel oxide films. Our results are of importance in a number of technological applications, among them, batteries, fuel cells, electrochromic and ferroelectric materials, corrosion protection, as well as environmental speciation and remediation.

  4. Slow dynamics of nanocomposite polymer aerogels as revealed by X-ray photocorrelation spectroscopy (XPCS)

    SciTech Connect (OSTI)

    Hernández, Rebeca, E-mail: rhernandez@ictp.csic.es, E-mail: aurora.nogales@csic.es; Mijangos, Carmen [Instituto de Ciencia y Tecnología de Polímeros, ICTP-CSIC, Juan de la Cierva, 3, 28006 Madrid (Spain)] [Instituto de Ciencia y Tecnología de Polímeros, ICTP-CSIC, Juan de la Cierva, 3, 28006 Madrid (Spain); Nogales, Aurora, E-mail: rhernandez@ictp.csic.es, E-mail: aurora.nogales@csic.es; Ezquerra, Tiberio A. [Instituto de Estructura de la Materia, IEM-CSIC, Serrano 121, 28006 Madrid (Spain)] [Instituto de Estructura de la Materia, IEM-CSIC, Serrano 121, 28006 Madrid (Spain); Sprung, Michael [Petra III at DESY, Notkestr. 85, 22607 Hamburg (Germany)] [Petra III at DESY, Notkestr. 85, 22607 Hamburg (Germany)

    2014-01-14T23:59:59.000Z

    We report on a novel slow dynamics of polymer xerogels, aerogels, and nanocomposite aerogels with iron oxide nanoparticles, as revealed by X-ray photon correlation spectroscopy. The polymer aerogel and its nanocomposite aerogels, which are porous in nature, exhibit hyper-diffusive dynamics at room temperature. In contrast, non-porous polymer xerogels exhibit an absence of this peculiar dynamics. This slow dynamical process has been assigned to a relaxation of the characteristic porous structure of these materials and not to the presence of nanoparticles.

  5. Polarity of semipolar wurtzite crystals: X-ray photoelectron diffraction from GaN(101?1) and GaN(202?1) surfaces

    SciTech Connect (OSTI)

    Romanyuk, O., E-mail: romanyuk@fzu.cz; Ji?í?ek, P.; Bartoš, I. [Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, 162 53 Prague (Czech Republic); Paskova, T. [Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, North Carolina 27606 (United States)

    2014-09-14T23:59:59.000Z

    Polarity of semipolar GaN(101?1) (101?1?) and GaN(202?1) (202?1?) surfaces was determined with X-ray photoelectron diffraction (XPD) using a standard MgK? source. The photoelectron emission from N 1s core level measured in the a-plane of the crystals shows significant differences for the two crystal orientations within the polar angle range of 80–100° from the (0001) normal. It was demonstrated that XPD polar plots recorded in the a-plane are similar for each polarity of the GaN(101?1) and GaN(202?1) crystals if referred to (0001) crystal axes. For polarity determinations of all important GaN(h0h?l) semipolar surfaces, the above given polar angle range is suitable.

  6. Probing bismuth ferrite nanoparticles by hard x-ray photoemission: Anomalous occurrence of metallic bismuth

    SciTech Connect (OSTI)

    Chaturvedi, Smita; Rajendra, Ranguwar; Ballav, Nirmalya; Kulkarni, Sulabha, E-mail: s.kulkarni@iiserpune.ac.in [Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pune 411008 (India); Sarkar, Indranil [DESY Photon Science, Deutsches Elektronen-Synchrotron, 22607 Hamburg (Germany); Shirolkar, Mandar M. [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Jeng, U-Ser; Yeh, Yi-Qi [National Synchrotron Radiation Research Center, 101, Hsin-Ann Road, Science Park, Hsinchu 3007-6, Taiwan (China)

    2014-09-08T23:59:59.000Z

    We have investigated bismuth ferrite nanoparticles (?75?nm and ?155?nm) synthesized by a chemical method, using soft X-ray (1253.6?eV) and hard X-ray (3500, 5500, and 7500?eV) photoelectron spectroscopy. This provided an evidence for the variation of chemical state of bismuth in crystalline, phase pure nanoparticles. X-ray photoelectron spectroscopy analysis using Mg K? (1253.6?eV) source showed that iron and bismuth were present in both Fe{sup 3+} and Bi{sup 3+} valence states as expected for bismuth ferrite. However, hard X-ray photoelectron spectroscopy analysis of the bismuth ferrite nanoparticles using variable photon energies unexpectedly showed the presence of Bi{sup 0} valence state below the surface region, indicating that bismuth ferrite nanoparticles are chemically inhomogeneous in the radial direction. Consistently, small-angle X-ray scattering reveals a core-shell structure for these radial inhomogeneous nanoparticles.

  7. First results from the high-brightness x-ray spectroscopy beamline 9. 3.1 at ALS

    SciTech Connect (OSTI)

    Ng, W.; Jones, G.; Perera, R.C.C.

    1995-10-01T23:59:59.000Z

    Beamline 9.3.1 at the Advanced Light Source (ALS) is a windowless beamline, covering the 1-6 keV photon-energy range. This beamline is designed to achieve the goal of high brightness at the sample for use in the X-ray Atomic and Molecular Spectroscopy (XAMS) science, surface and interface science, biology, and x-ray optical development programs at ALS. X-ray absorption and time of flight photoemission measurements in 2 - 5 keV photon energy along with the flux, resolution, spot size and stability of the beamline will be discussed. Prospects for future XAMS measurements will also be presented.

  8. Core and Valence Excitations in Resonant X-ray Spectroscopy using Restricted Excitation Window Time-dependent Density Functional Theory

    SciTech Connect (OSTI)

    Zhang, Yu; Biggs, Jason D.; Healion, Daniel; Govind, Niranjan; Mukamel, Shaul

    2012-11-21T23:59:59.000Z

    We report simulations of X-ray absorption near edge structure (XANES), resonant inelastic X-ray scattering (RIXS) and 1D stimulated X-ray Raman spectroscopy (SXRS) signals of cysteine at the oxygen, nitrogen and sulfur K and L2,3 edges. The simulated XANES signals from the restricted window time-dependent density functional theory (REW-TDDFT) and the static exchange (STEX) method are compared with experiments, showing that REW-TDDFT is more accurate and computationally less expensive than STEX. Simulated RIXS and 1D SXRS signals from REW-TDDFT give some insights on the correlation of different excitations in the molecule.

  9. Bimolecular reaction dynamics from photoelectron spectroscopy of negative ions

    SciTech Connect (OSTI)

    Bradforth, S.E.

    1992-11-01T23:59:59.000Z

    The transition state region of a neutral bimolecular reaction may be experimentally investigated by photoelectron spectroscopy of an appropriate negative ion. The photoelectron spectrum provides information on the spectroscopy and dynamics of the short lived transition state and may be used to develop model potential energy surfaces that are semi-quantitative in this important region. The principles of bound {yields} bound negative ion photoelectron spectroscopy are illustrated by way of an example: a full analysis of the photoelectron bands of CN{sup {minus}}, NCO{sup {minus}} and NCS{sup {minus}}. Transition state photoelectron spectra are presented for the following systems Br + HI, Cl + HI, F + HI, F + CH{sub 3}0H,F + C{sub 2}H{sub 5}OH,F + OH and F + H{sub 2}. A time dependent framework for the simulation and interpretation of the bound {yields} free transition state photoelectron spectra is subsequently developed and applied to the hydrogen transfer reactions Br + HI, F + OH {yields} O({sup 3}P, {sup 1}D) + HF and F + H{sub 2}. The theoretical approach for the simulations is a fully quantum-mechanical wave packet propagation on a collinear model reaction potential surface. The connection between the wavepacket time evolution and the photoelectron spectrum is given by the time autocorrelation function. For the benchmark F + H{sub 2} system, comparisons with three-dimensional quantum calculations are made.

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

    SciTech Connect (OSTI)

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

    2013-06-01T23:59:59.000Z

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

  11. X-ray imaging crystal spectroscopy for use in plasma transport research

    SciTech Connect (OSTI)

    Reinke, M. L.; Podpaly, Y. A.; Hutchinson, I. H.; Rice, J. E.; Gao, C.; Greenwald, M.; Howard, N. T.; Hubbard, A.; Hughes, J. W.; White, A. E.; Wolfe, S. M. [MIT-Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Bitter, M.; Delgado-Aparicio, L.; Hill, K.; Pablant, N. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2012-11-15T23:59:59.000Z

    This research describes advancements in the spectral analysis and error propagation techniques associated with x-ray imaging crystal spectroscopy (XICS) that have enabled this diagnostic to be used to accurately constrain particle, momentum, and heat transport studies in a tokamak for the first time. Doppler tomography techniques have been extended to include propagation of statistical uncertainty due to photon noise, the effect of non-uniform instrumental broadening as well as flux surface variations in impurity density. These methods have been deployed as a suite of modeling and analysis tools, written in interactive data language (IDL) and designed for general use on tokamaks. Its application to the Alcator C-Mod XICS is discussed, along with novel spectral and spatial calibration techniques. Example ion temperature and radial electric field profiles from recent I-mode plasmas are shown, and the impact of poloidally asymmetric impurity density and natural line broadening is discussed in the context of the planned ITER x-ray crystal spectrometer.

  12. Millisecond Kinetics of Nanocrystal Cation Exchange UsingMicrofluidic X-ray Absorption Spectroscopy

    SciTech Connect (OSTI)

    Chan, Emory M.; Marcus, Matthew A.; Fakra, Sirine; Elnaggar,Mariam S.; Mathies, Richard A.; Alivisatos, A. Paul

    2007-05-07T23:59:59.000Z

    We describe the use of a flow-focusing microfluidic reactorto measure the kinetics of theCdSe-to-Ag2Se nanocrystal cation exchangereaction using micro-X-ray absorption spectroscopy (mu XAS). The smallmicroreactor dimensions facilitate the millisecond mixing of CdSenanocrystal and Ag+ reactant solutions, and the transposition of thereaction time onto spatial coordinates enables the in situ observation ofthe millisecond reaction with mu XAS. XAS spectra show the progression ofCdSe nanocrystals to Ag2Se over the course of 100 ms without the presenceof long-lived intermediates. These results, along with supporting stoppedflow absorption experiments, suggest that this nanocrystal cationexchange reaction is highly efficient and provide insight into how thereaction progresses in individual particles. This experiment illustratesthe value and potential of in situ microfluidic X-ray synchrotrontechniques for detailed studies of the millisecond structuraltransformations of nanoparticles and other solution-phase reactions inwhich diffusive mixing initiates changes in local bond structures oroxidation states.

  13. High-rate x-ray spectroscopy in mammography with a CdTe detector: A digital pulse processing approach

    SciTech Connect (OSTI)

    Abbene, L.; Gerardi, G.; Principato, F.; Del Sordo, S.; Ienzi, R.; Raso, G. [Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze, Edificio 18, Palermo 90128 (Italy) and INAF/IASF Palermo, Via Ugo La Malfa 153, 90146 Palermo (Italy); Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze, Edificio 18, Palermo 90128 (Italy); INAF/IASF Palermo, Via Ugo La Malfa 153, 90146 Palermo (Italy); Istituto di Radiologia, Policlinico, 90100 Palermo (Italy); Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze, Edificio 18, Palermo 90128 (Italy)

    2010-12-15T23:59:59.000Z

    Purpose:Direct measurement of mammographic x-ray spectra under clinical conditions is a difficult task due to the high fluence rate of the x-ray beams as well as the limits in the development of high resolution detection systems in a high counting rate environment. In this work we present a detection system, based on a CdTe detector and an innovative digital pulse processing (DPP) system, for high-rate x-ray spectroscopy in mammography. Methods: The DPP system performs a digital pile-up inspection and a digital pulse height analysis of the detector signals, digitized through a 14-bit, 100 MHz digitizer, for x-ray spectroscopy even at high photon counting rates. We investigated on the response of the digital detection system both at low (150 cps) and at high photon counting rates (up to 500 kcps) by using monoenergetic x-ray sources and a nonclinical molybdenum anode x-ray tube. Clinical molybdenum x-ray spectrum measurements were also performed by using a pinhole collimator and a custom alignment device. Results: The detection system shows excellent performance up to 512 kcps with an energy resolution of 4.08% FWHM at 22.1 keV. Despite the high photon counting rate (up to 453 kcps), the molybdenum x-ray spectra, measured under clinical conditions, are characterized by a low number of pile-up events. The agreement between the attenuation curves and the half value layer values, obtained from the measured spectra, simulated spectra, and from the exposure values directly measured with an ionization chamber, also shows the accuracy of the measurements. Conclusions: These results make the proposed detection system a very attractive tool for both laboratory research and advanced quality controls in mammography.

  14. Electronic Structure of Transition Metal-Cysteine Complexes From X-Ray Absorption Spectroscopy

    SciTech Connect (OSTI)

    Leung, B.O.; Jalilehvand, F.; Szilagyi, R.K.

    2009-05-19T23:59:59.000Z

    The electronic structures of Hg{sup II}, Ni{sup II}, Cr{sup III}, and Mo{sup V} complexes with cysteine were investigated by sulfur K-edge X-ray absorption near-edge structure (XANES) spectroscopy and density functional theory. The covalency in the metal-sulfur bond was determined by analyzing the intensities of the electric-dipole allowed pre-edge features appearing in the XANES spectra below the ionization threshold. Because of the well-defined structures of the selected cysteine complexes, the current work provides a reference set for further sulfur K-edge XAS studies of bioinorganic active sites with transition metal-sulfur bonds from cysteine residues as well as more complex coordination compounds with thiolate ligands.

  15. Tin Valence and Local Environments in Silicate Glasses as Determined From X-ray Absorption Spectroscopy

    SciTech Connect (OSTI)

    McKeown,D.; Buechele, A.; Gan, H.; Pegg, I.

    2008-01-01T23:59:59.000Z

    X-ray absorption spectroscopy (XAS) was used to characterize the tin (Sn) environments in four borosilicate glass nuclear waste formulations, two silicate float glasses, and three potassium aluminosilicate glasses. Sn K-edge XAS data of most glasses investigated indicate Sn4+O6 units with average Sn-O distances near 2.03 Angstroms. XAS data for a float glass fabricated under reducing conditions show a mixture of Sn4+O6 and Sn2+O4 sites. XAS data for three glasses indicate Sn-Sn distances ranging from 3.43 to 3.53 Angstroms, that suggest Sn4+O6 units linking with each other, while the 4.96 Angstroms Sn-Sn distance for one waste glass suggests clustering of unlinked Sn4+O6 units.

  16. Photoelectron spectroscopy of solvated electrons in alcohol and acetonitrile microjets

    E-Print Network [OSTI]

    Neumark, Daniel M.

    Photoelectron spectroscopy of solvated electrons in alcohol and acetonitrile microjets Alexander T in methanol, ethanol, and acetonitrile microjets are reported. Solvated electrons are generated. Two features are observed in acetonitrile at 2.61 Ã? 0.11 eV and 3.67 Ã? 0.15 eV, attributed

  17. Probing Reaction Dynamics of Transition-Metal Complexes in Solution via Time-Resolved Soft X-ray Spectroscopy

    SciTech Connect (OSTI)

    Huse, Nils; Kim, Tae Kyu; Khalil, Munira; Jamula, Lindsey; McCusker, James K.; Schoenlein, Robert W.

    2010-05-02T23:59:59.000Z

    We report the first time-resolved soft x-ray measurements of solvated transition-metal complexes. L-edge spectroscopy directly probes dynamic changes in ligand-field splitting of 3d orbitals associated with the spin transition, and mediated by changes in ligand-bonding.

  18. THREE NEW GALACTIC CENTER X-RAY SOURCES IDENTIFIED WITH NEAR-INFRARED SPECTROSCOPY

    SciTech Connect (OSTI)

    DeWitt, Curtis [Department of Physics, University of California, Davis, CA 95616 (United States); Bandyopadhyay, Reba M.; Eikenberry, Stephen S.; Sarajedini, Ata [Department of Astronomy, University of Florida, 211 Bryant Space Center, P.O. Box 112055, Gainesville, FL 32611 (United States); Sellgren, Kris [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Blum, Robert; Olsen, Knut [National Optical Astronomy Observatories, Tucson, AZ 85719 (United States); Bauer, Franz E., E-mail: curtis.n.dewitt@nasa.gov [Departamento de Astronomía y Astrofísica, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22 (Chile)

    2013-11-01T23:59:59.000Z

    We have conducted a near-infrared spectroscopic survey of 47 candidate counterparts to X-ray sources discovered by the Chandra X-Ray Observatory near the Galactic center (GC). Though a significant number of these astrometric matches are likely to be spurious, we sought out spectral characteristics of active stars and interacting binaries, such as hot, massive spectral types or emission lines, in order to corroborate the X-ray activity and certify the authenticity of the match. We present three new spectroscopic identifications, including a Be high-mass X-ray binary (HMXB) or a ? Cassiopeiae (Cas) system, a symbiotic X-ray binary, and an O-type star of unknown luminosity class. The Be HMXB/? Cas system and the symbiotic X-ray binary are the first of their classes to be spectroscopically identified in the GC region.

  19. Design and operation of an in situ high pressure reaction cell for x-ray absorption spectroscopy.

    SciTech Connect (OSTI)

    Bare, S. R.; Yang, N.; Kelly, S. D.; Mickelson, G. E.; Modica, F. S.; UOP LLC; EXAFS Analysis

    2007-01-01T23:59:59.000Z

    The design and initial operation of an in situ catalysis reaction cell for x-ray absorption spectroscopy measurements at high pressure is described. The design is based on an x-ray transparent tube fabricated from beryllium. This forms a true plug flow reactor for catalysis studies. The reactor is coupled to a portable microprocessor-controlled versatile feed system, and incorporates on-line analysis of reaction products. XAFS data recorded during the reduction of a NiRe/carbon catalyst at 4 bar are used to illustrate the performance of the reactor.

  20. Monitoring Long-Range Electron Transfer Pathways in Proteins by Stimulated Attosecond Broadband X-ray Raman Spectroscopy

    SciTech Connect (OSTI)

    Zhang, Yu; Biggs, Jason; Govind, Niranjan; Mukamel, Shaul

    2014-10-09T23:59:59.000Z

    Long-range electron transfer (ET) plays a key role in many biological energy conversion and synthesis processes. We show that nonlinear spectroscopy with attosecond X-ray pulses provides a real time movie of the evolving oxidation states and electron densities around atoms, and can probe these processes with high spatial and temporal resolution. This is demonstrated in a simulation study of the stimulated X-ray Raman (SXRS) signals in Re-modified azurin, which had long served as a benchmark for long-range ET in proteins. Nonlinear SXRS signals are sensitive to the local electronic structure and should offer a novel window for long-range ET.

  1. Design and Operation of an In Situ High Pressure Reaction Cell for X-Ray Absorption Spectroscopy

    SciTech Connect (OSTI)

    Bare, Simon R.; Mickelson, G. E.; Modica, F. S. [UOP LLC, Des Plaines, IL, 60016 (United States); Yang, N. [Argonne National Laboratory, Argonne, IL 60439 (United States); Kelly, S. D. [EXAFS Analysis, Bolingbrook, IL 6044 (United States)

    2007-02-02T23:59:59.000Z

    The design and initial operation of an in situ catalysis reaction cell for x-ray absorption spectroscopy measurements at high pressure is described. The design is based on an x-ray transparent tube fabricated from beryllium. This forms a true plug flow reactor for catalysis studies. The reactor is coupled to a portable microprocessor-controlled versatile feed system, and incorporates on-line analysis of reaction products. XAFS data recorded during the reduction of a NiRe/carbon catalyst at 4 bar are used to illustrate the performance of the reactor.

  2. X-ray absorption spectroscopy at the Ni-K edge in Stackhousia tryonii Bailey hyperaccumulator

    E-Print Network [OSTI]

    Kachenko, A.

    2009-01-01T23:59:59.000Z

    Micro x-ray ?uorescence ( -XRF) mapping was performed using15 RESULTS AND DISCUSSION -XRF imaging was used to determinelocalisation in planta. Typical -XRF maps obtained of stem,

  3. ON RELATIVISTIC DISK SPECTROSCOPY IN COMPACT OBJECTS WITH X-RAY CCD CAMERAS

    E-Print Network [OSTI]

    Miller, J. M.

    X-ray charge-coupled devices (CCDs) are the workhorse detectors of modern X-ray astronomy. Typically covering the 0.3-10.0 keV energy range, CCDs are able to detect photoelectric absorption edges and K shell lines from ...

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

    SciTech Connect (OSTI)

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

    2012-06-01T23:59:59.000Z

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

  5. Soft X-ray Spectroscopy Study of the Electronic Structure of Oxidized and Partially Oxidized Magnetite Nanoparticles

    SciTech Connect (OSTI)

    Gilbert, Benjamin; Katz, Jordan E.; Denlinger, Jonathan D.; Yin, Yadong; Falcone, Roger; Waychunas, Glenn A.

    2010-10-24T23:59:59.000Z

    The crystal structure of magnetite nanoparticles may be transformed to maghemite by complete oxidation, but under many relevant conditions the oxidation is partial, creating a mixed-valence material with structural and electronic properties that are poorly characterized. We used X-ray diffraction, Fe K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy, and soft X-ray absorption and emission spectroscopy to characterize the products of oxidizing uncoated and oleic acid-coated magnetite nanoparticles in air. The oxidization of uncoated magnetite nanoparticles creates a material that is structurally and electronically indistinguishable from maghemite. By contrast, while oxidized oleic acid-coated nanoparticles are also structurally indistinguishable from maghemite, Fe L-edge spectroscopy revealed the presence of interior reduced iron sites even after a 2-year period. We used X-ray emission spectroscopy at the O K-edge to study the valence bands (VB) of the iron oxide nanoparticles, using resonant excitation to remove the contributions from oxygen atoms in the ligands and from low-energy excitations that obscured the VB edge. The bonding in all nanoparticles was typical of maghemite, with no detectable VB states introduced by the long-lived, reduced-iron sites in the oleic acid-coated sample. However, O K-edge absorption spectroscopy observed a 0.2 eV shift in the position of the lowest unoccupied states in the coated sample, indicating an increase in the semiconductor band gap relative to bulk stoichiometric maghemite that was also observed by optical absorption spectroscopy. The results show that the ferrous iron sites within ferric iron oxide nanoparticles coated by an organic ligand can persist under ambient conditions with no evidence of a distinct interior phase and can exert an effect on the global electronic and optical properties of the material. This phenomenon resembles the band gap enlargement caused by electron accumulation in the conduction band of TiO2.

  6. Probing reaction dynamics of transition-metal complexes in solution via time-resolved soft x-ray spectroscopy

    SciTech Connect (OSTI)

    Huse, N.; Kim, T.-K.; Khalil, M.; Jamula, L.; McCusker, J.K.; Schoenlein, R.W.

    2008-08-01T23:59:59.000Z

    We report the first time-resolved soft x-ray measurements of solvated transition-metal complexes. L-edge spectroscopy directly probes dynamic changes in ligand-field splitting of 3d orbitals associated with the spin transition, and mediated by changes in ligand-bonding. We report the first time-resolved soft x-ray spectroscopy of solution-phase molecular dynamics. Changes in ligand-field splitting and spin-state populations in 3d orbitals of the Fe{sup II} complex are directly probed via transient absorption changes of the Fe L{sub 2} and L{sub 3} edges following photo-induced metal-to-ligand charge transfer. With the emergence of high-flux ultrafast soft x-ray sources, details on interplay between atomic structure, electronic states, and spin contributions will be revealed. Our experimental approach opens the door to femtosecond soft x-ray investigations of liquid phase chemistry that have previously been inaccessible.

  7. X-ray spectroscopy of gamma-ray bursts: the path to the progenitor

    E-Print Network [OSTI]

    Davide Lazzati; Rosalba Perna; Gabriele Ghisellini

    2002-01-17T23:59:59.000Z

    Despite great observational and theoretical effort, the burst progenitor is still a mysterious object. It is generally accepted that one of the best ways to unveil its nature is the study of the properties of the close environment in which the explosion takes place. We discuss the potentiality and feasibility of time resolved X-ray spectroscopy, focusing on the prompt gamma-ray phase. We show that the study of absorption features (or continuum absorption) can reveal the radial structure of the close environment, unaccessible with different techniques. We discuss the detection of absorption in the prompt and afterglow spectra of several bursts, showing how these are consistent with gamma-ray bursts taking place in dense regions. In particular, we show that the radius and density of the surrounding cloud can be measured through the evolution of the column density in the prompt burst phase. The derived cloud properties are similar to those of the star forming cocoons and globules within molecular clouds. We conclude that the burst are likely associated with the final evolutionary stages of massive stars.

  8. Identification of lead chemical form in mine waste materials by X-ray absorption spectroscopy

    SciTech Connect (OSTI)

    Taga, Raijeli L.; Ng, Jack [University of Queensland, National Research Centre for Environmental Toxicology (EnTox), Brisbane, 4108 (Australia); Zheng Jiajia; Huynh, Trang; Noller, Barry [University of Queensland, Centre for Mined Land Rehabilitation, Brisbane, 4072 (Australia); Harris, Hugh H. [School of Chemistry and Physics, University of Adelaide, Adelaide, 5005 (Australia)

    2010-06-23T23:59:59.000Z

    X-ray absorption spectroscopy (XAS) provides a direct means for measuring lead chemical forms in complex samples. In this study, XAS was used to identify the presence of plumbojarosite (PbFe{sub 6}(SO{sub 4}){sub 4}(OH){sub 12}) by lead L{sub 3}-edge XANES spectra in mine waste from a small gold mining operation in Fiji. The presence of plumbojarosite in tailings was confirmed by XRD but XANES gave better resolution. The potential for human uptake of Pb from tailings was measured using a physiologically based extract test (PBET), an in-vitro bioaccessibility (BAc) method. The BAc of Pb was 55%. Particle size distribution of tailings indicated that 40% of PM{sub 10} particulates exist which could be a potential risk for respiratory effects via the inhalation route. Food items collected in the proximity of the mine site had lead concentrations which exceed food standard guidelines. Lead within the mining lease exceeded sediment guidelines. The results from this study are used to investigate exposure pathways via ingestion and inhalation for potential risk exposure pathways of Pb in that locality. The highest Pb concentration in soil and tailings was 25,839 mg/kg, exceeding the Australian National Environment Protection Measure (NEPM) soil health investigation levels.

  9. Speciation of selenium in stream insects using X-ray absorption spectroscopy

    SciTech Connect (OSTI)

    Ruwandi Andrahennadi; Mark Wayland; Ingrid J. Pickering [University of Saskatchewan, Saskatoon, SK (Canada). Department of Geological Sciences

    2007-11-15T23:59:59.000Z

    Selenium contamination in the environment is a widespread problem affecting insects and other wildlife. Insects occupy a critical middle link and aid in trophic transfer of selenium in many terrestrial and freshwater food chains, but the mechanisms of selenium uptake through the food chain are poorly understood. In particular, biotransformation of selenium by insects into different chemical forms will greatly influence how toxic or benign the selenium is to that organism or to its predators. We have used X-ray absorption spectroscopy (XAS) to identify the chemical form of selenium in insects inhabiting selenium contaminated streams near Hinton, Alberta (Canada). Selenium K near-edge spectra indicate a variability of selenium speciation among the insects that included mayflies (Ephemeroptera), stoneflies (Plecoptera), caddisflies (Trichoptera), and craneflies (Diptera). Higher percentages of inorganic selenium were observed in primary consumers, detritivores, and filter feeders than in predatory insects. Among the organic forms of selenium, organic selenides constituted a major fraction in most organisms. A species modeled as trimethylselenonium was observed during the pupal stage of caddisflies. These results provide insights into how the insects cope with their toxic cargo, including how the selenium is biotransformed into less toxic forms and how it can be eliminated from the insects. More broadly, this study demonstrates the strengths of XAS to probe the effects of heavy elements at trace levels in insects from the field.

  10. ON THE PROSPECT OF CONSTRAINING BLACK HOLE SPIN THROUGH X-RAY SPECTROSCOPY OF HOTSPOTS

    E-Print Network [OSTI]

    Yaqoob, Tahir

    Future X-ray instrumentation is expected to allow us to significantly improve the constraints derived from the Fe?K lines in active galactic nuclei, such as the black hole angular momentum (spin) and the inclination angle ...

  11. X-ray afterglows and spectroscopy of Gamma-Ray Bursts

    E-Print Network [OSTI]

    Luigi Piro

    2004-02-26T23:59:59.000Z

    I will review the constraints set by X-ray measurements of afterglows on several issues of GRB, with particular regard to the fireball model, the environment, the progenitor and dark GRB.

  12. Imaging X-ray spectroscopy with micro-X and Chandra

    E-Print Network [OSTI]

    Rutherford, John (John Morton)

    2013-01-01T23:59:59.000Z

    High spectral resolution observations of X-ray phenomena have the potential to uncover new physics. Currently, only point sources can be probed with high resolution spectra, using gratings. Extended objects like supernova ...

  13. Towards simultaneous measurements of electronic and structural properties in ultra-fast x-ray free electron laser absorption spectroscopy experiments

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gaudin, J.; Fourment, C.; Cho, B. I.; Engelhorn, K.; Galtier, E.; Harmand, M.; Leguay, P. M.; Lee, H. J.; Nagler, B.; Nakatsutsumi, M.; et al

    2014-04-17T23:59:59.000Z

    The rapidly growing ultrafast science with X-ray lasers unveils atomic scale processes with unprecedented time resolution bringing the so called “molecular movie” within reach. X-ray absorption spectroscopy is one of the most powerful x-ray techniques providing both local atomic order and electronic structure when coupled with ad-hoc theory. Collecting absorption spectra within few x-ray pulses is possible only in a dispersive setup. We demonstrate ultrafast time-resolved measurements of the LIII-edge x-ray absorption near-edge spectra of irreversibly laser excited Molybdenum using an average of only few x-ray pulses with a signal to noise ratio limited only by the saturation level ofmore »the detector. The simplicity of the experimental set-up makes this technique versatile and applicable for a wide range of pump-probe experiments, particularly in the case of non-reversible processes.« less

  14. In Situ Ambient Pressure X-ray Photoelectron Spectroscopy Studies of Lithium-Oxygen Redox Reactions

    E-Print Network [OSTI]

    Lu, Yi-chun

    The lack of fundamental understanding of the oxygen reduction and oxygen evolution in nonaqueous electrolytes significantly hinders the development of rechargeable lithium-air batteries. Here we employ a solid-state ...

  15. Profiling nitrogen in ultrathin silicon oxynitrides with angle-resolved x-ray photoelectron spectroscopy

    E-Print Network [OSTI]

    Gustafsson, Torgny

    medium energy ion scattering and secondary ion mass spectrometry analysis. Preferential nitrogen by low energy ion (15 N2) implantation. The nitrogen profile and nitrogen chemical bonding states only minor in- crease in the dielectric constant compared to SiO2 but is still favored over other high

  16. Depth-profiling X-ray photoelectron spectroscopy (XPS) analysis of interlayer diffusion in polyelectrolyte multilayers

    E-Print Network [OSTI]

    Rubner, Michael F.

    Functional organic thin films often demand precise control over the nanometer-level structure. Interlayer diffusion of materials may destroy this precise structure; therefore, a better understanding of when interlayer ...

  17. X-Ray Photoelectron Spectroscopy (XPS) Applied to Soot & What It Can Do for

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your DensityEnergy U.S.-China Electric VehicleCenters |-- 9:00 AM OpeningWorld's LargestYou | Department of

  18. Ambient Pressure Photoelectron Spectroscopy Using Soft X-ray and Hard

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisiting the TWP TWPAlumni Alumni PARC/I-CARES CERTIFICATE IN RENEWABLEInitiative

  19. In-situ X-ray Photoelectron Spectroscopy of a Catalyst for Artificial

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn Other News Community Connections: YourIn-Situ

  20. Multidimensional x-ray spectroscopy of valence and core excitations in Jason D. Biggs, Yu Zhang, Daniel Healion, and Shaul Mukamel

    E-Print Network [OSTI]

    Mukamel, Shaul

    Multidimensional x-ray spectroscopy of valence and core excitations in cysteine Jason D. Biggs, Yu and core excitations in cysteine Jason D. Biggs, Yu Zhang, Daniel Healion, and Shaul Mukamela) Department

  1. X-Ray Spectroscopy of the Classical Nova V458 Vulpeculae with Suzaku

    E-Print Network [OSTI]

    Masahiro Tsujimoto; Dai Takei; Jeremy J. Drake; Jan-Uwe Ness; Shunji Kitamoto

    2008-10-17T23:59:59.000Z

    We conducted a target of opportunity X-ray observation of the classical nova V458 Vulpeculae 88 days after the explosion using the Suzaku satellite. With a 20 ks exposure, the X-ray Imaging Spectrometer detected X-ray emission significantly harder than typical super-soft source emission. The X-ray spectrum shows K lines from N, Ne, Mg, Si, and S, and L-series emission from Fe in highly ionized states. The spectrum can be described by a single temperature (0.64 keV) thin thermal plasma model in collisional equilibrium with a hydrogen-equivalent extinction column density of ~3e21/cm2, a flux of ~1e-12 erg/s/cm2, and a luminosity of ~6e34 erg/s in the 0.3-3.0 keV band at an assumed distance of 13 kpc. We found a hint of an enhancement of N and deficiencies of O and Fe relative to other metals. The observed X-ray properties can be interpreted as the emission arising from shocks of ejecta from an ONe-type nova.

  2. X-Ray Spectroscopy of the Classical Nova V458 Vulpeculae with Suzaku

    E-Print Network [OSTI]

    Tsujimoto, Masahiro; Drake, Jeremy J; Ness, Jan-Uwe; Kitamoto, Shunji

    2008-01-01T23:59:59.000Z

    We conducted a target of opportunity X-ray observation of the classical nova V458 Vulpeculae 88 days after the explosion using the Suzaku satellite. With a 20 ks exposure, the X-ray Imaging Spectrometer detected X-ray emission significantly harder than typical super-soft source emission. The X-ray spectrum shows K lines from N, Ne, Mg, Si, and S, and L-series emission from Fe in highly ionized states. The spectrum can be described by a single temperature (0.64 keV) thin thermal plasma model in collisional equilibrium with a hydrogen-equivalent extinction column density of ~3e21/cm2, a flux of ~1e-12 erg/s/cm2, and a luminosity of ~6e34 erg/s in the 0.3-3.0 keV band at an assumed distance of 13 kpc. We found a hint of an enhancement of N and deficiencies of O and Fe relative to other metals. The observed X-ray properties can be interpreted as the emission arising from shocks of ejecta from an ONe-type nova.

  3. Ligand-field symmetry effects in Fe(II) polypyridyl compounds probed by transient X-ray absorption spectroscopy

    SciTech Connect (OSTI)

    Cho, Hana; Strader, Matthew L.; Hong, Kiryong; Jamula, Lindsey; Kim, Tae Kyu; Groot, Frank M. F. de; McCusker, James K.; Schoenlein, Robert W.; Huse, Nils

    2012-02-28T23:59:59.000Z

    Ultrafast excited-state evolution in polypyridyl FeII complexes are of fundamental interest for understanding the origins of the sub-ps spin-state changes that occur upon photoexcitation of this class of compounds as well as for the potential impact such ultrafast dynamics have on incorporation of these compounds in solar energy conversion schemes or switchable optical storage technologies. We have demonstrated that ground-state and, more importantly, ultrafast time-resolved x-ray absorption methods can offer unique insights into the interplay between electronic and geometric structure that underpin the photo-induced dynamics of this class of compounds. The present contribution examines in greater detail how the symmetry of the ligand field surrounding the metal ion can be probed using these x-ray techniques. In particular, we show that steady-state K-edge spectroscopy of the nearest-neighbour nitrogen atoms reveals the characteristic chemical environment of the respective ligands and suggests an interesting target for future charge-transfer femtosecond and attosecond spectroscopy in the x-ray water window.

  4. Double core-hole spectroscopy of transient plasmas produced in the interaction of ultraintense x-ray pulses with neon

    E-Print Network [OSTI]

    Gao, Cheng; Yuan, Jianmin

    2015-01-01T23:59:59.000Z

    Double core-hole (DCH) spectroscopy is investigated systematically for neon atomic system in the interaction with ultraintense x-ray pulses with photon energy from 937 eV to 2000 eV. A time-dependent rate equation, implemented in the detailed level accounting approximation, is utilized to study the dynamical evolution of the level population and emission properties of the highly transient plasmas. For x-ray pulses with photon energy in the range of 937-1030 eV, where $1s\\rightarrow 2p$ resonance absorption from single core-hole (SCH) states of neon charge states exist, inner-shell resonant absorption (IRA) effects play important roles in the time evolution of population and DCH spectroscopy. Such IRA physical effects are illustrated in detail by investigating the interaction of x-ray pulses at a photon energy of 944 eV, which corresponds to the $1s\\rightarrow 2p$ resonant absorption from the SCH states ($1s2s^22p^4$, $1s2s2p^5$ and $1s2p^6$) of Ne$^{3+}$. After averaging over the space and time distribution o...

  5. Femtosecond soft x-ray spectroscopy of solvated transition metal complexes: Deciphering the interplay of electronic and structural dynamics

    SciTech Connect (OSTI)

    Huse, Nils; Cho, Hana; Hong, Kiryong; Jamula, Lindsey; de Groot, Frank M. F.; Kim, Tae Kyu; McCusker, James K.; Schoenlein, Robert W.

    2011-03-09T23:59:59.000Z

    We present the first implementation of femtosecond soft X-ray spectroscopy as an ultrafast direct probe of the excited-state valence orbitals in solution-phase molecules. This method is applied to photoinduced spin crossover of [Fe(tren(py)3)]2+, where the ultrafast spinstate conversion of the metal ion, initiated by metal-to-ligand charge-transfer excitation, is directly measured using the intrinsic spin-state selectivity of the soft X-ray L-edge transitions. Our results provide important experimental data concerning the mechanism of ultrafast spin-state conversion and subsequent electronic and structural dynamics, highlighting the potential of this technique to study ultrafast phenomena in the solution phase.

  6. X-ray Absorption Spectroscopy of the Multi-phase Interstellar Medium: Oxygen and Neon Abundances

    E-Print Network [OSTI]

    Yangsen Yao; Q. Daniel Wang

    2005-12-19T23:59:59.000Z

    X-ray absorption spectroscopy provides a potentially powerful tool in determining the metal abundances in various phases of the interstellar medium (ISM). We present a case study of the sight line toward 4U 1820-303 (Galactic coordinates l, b=2.79, -7.91 and distance = 7.6 kpc), based on Chandra Grating observations. The detection of OI, OII, OIII, OVII, OVIII, and NeIX Kalpha absorption lines allows us to measure the atomic column densities of the neutral, warm ionized, and hot phases of the ISM through much of the Galactic disk. By comparing these measurements with the 21 cm hydrogen emission and with the pulsar dispersion measure along the same sight line, we estimate the mean oxygen abundances in the neutral and total ionized phases as 0.3(0.2, 0.6) and 2.2(1.1, 3.5) in units of Anders & Grevesse (1989) solar value. This significant oxygen abundance difference is apparently a result of molecule/dust grain destruction and recent metal enrichment in the warm ionized and hot phases. We also measure the column density of neon from its absorption edge and obtain the Ne/O ratio of the neutral plus warm ionized gas as 2.1(1.3, 3.5) solar. Accounting for the expected oxygen contained in molecules and dust grains would reduce the Ne/O ratio by a factor of ~1.5. From a joint-analysis of the OVII, OVIII, and NeIX lines, we obtain the Ne/O abundance ratio of the hot phase as 1.4(0.9, 2.1) solar, which is not sensitive to the exact temperature distribution assumed in the absorption line modeling. These comparable ISM Ne/O ratios for the hot and cooler gas are thus considerably less than the value (2.85+-0.07; 1sigma) recently inferred from corona emission of solar-like stars (Drake & Testa 2005). (abridged)

  7. ELECTRON SPECTROSCOPY OF SURFACES Elemental and Chemical Analysis with X-ray

    E-Print Network [OSTI]

    of the experiment is to make the students familiar with the fundamental principles and basic methodology of XPS be of relevance for a vast range of systems not only in condensed matter physics, chemistry, and materials science simple process. When a solid surface is irradiated with soft X-ray photons (Fig. 1a), an incident photon

  8. Suzaku Spectroscopy of the Extended X-Ray Emission in M17

    E-Print Network [OSTI]

    Yoshiaki Hyodo; Masahiro Tsujimoto; Kenji Hamaguchi; Katsuji Koyama; Shunji Kitamoto; Yoshitomo Maeda; Yohko Tsuboi; Yuichiro Ezoe

    2007-07-27T23:59:59.000Z

    We present the results of a Suzaku spectroscopic study of the soft extended X-ray emission in the HII region M17. The spectrum of the extended emission was obtained with a high signal-to-noise ratio in a spatially-resolved manner using the X-ray Imaging Spectrometer (XIS). We established that the contamination by unresolved point sources, the Galactic Ridge X-ray emission, the cosmic X-ray background, and the local hot bubble emission is negligible in the background-subtracted XIS spectrum of the diffuse emission. Half a dozen of emission lines were resolved clearly for the first time, including K lines of highly ionized O, Ne, and Mg as well as L series complex of Fe at 0.5--1.5 keV. Based on the diagnosis of these lines, we obtained the following results: (1) the extended emission is an optically-thin thermal plasma represented well by a single temperature of 3.0 +/- 0.4 MK, (2) the abundances of elements with emission lines in the diffuse spectrum are 0.1--0.3 solar, while those of bright discrete sources are 0.3--1.5 solar, (3) the metal abundances relative to each other in the diffuse emission are consistent with solar except for a Ne enhancement of a factor of 2, (4) both the plasma temperature and the chemical composition of the diffuse emission show no spatial variation across the studied spatial scale of about 5 pc.

  9. X-Ray Spectroscopy of II Pegasi: Coronal Temperature Structure, Abundances, and Variability

    E-Print Network [OSTI]

    Huenemoerder, David P.

    We have obtained high-resolution X-ray spectra of the coronally active binary II Pegasi (HD 224085), covering the wavelength range of 1.5-25 Å. For the first half of our 44 ks observation, the source was in a quiescent ...

  10. Center for X-Ray Optics, 1992

    SciTech Connect (OSTI)

    Not Available

    1993-08-01T23:59:59.000Z

    This report discusses the following topics: Center for X-Ray Optics; Soft X-Ray Imaging wit Zone Plate Lenses; Biological X-Ray microscopy; Extreme Ultraviolet Lithography for Nanoelectronic Pattern Transfer; Multilayer Reflective Optics; EUV/Soft X-ray Reflectometer; Photoemission Microscopy with Reflective Optics; Spectroscopy with Soft X-Rays; Hard X-Ray Microprobe; Coronary Angiography; and Atomic Scattering Factors.

  11. High Resolution Spectroscopy of X-ray Quasars: Searching for the X-ray Absorption from the Warm-Hot Intergalactic Medium

    E-Print Network [OSTI]

    Fang, Taotao

    We present a survey of six low- to moderate-redshift quasars with Chandra and XMM-Newton. The primary goal is to search for the narrow X-ray absorption lines produced by highly ionized metals in the warm-hot intergalactic ...

  12. Rotational Doppler effect in x-ray photoionization

    SciTech Connect (OSTI)

    Sun Yuping; Wang Chuankui [College of Physics and Electronics, Shandong Normal University, 250014 Jinan (China); Theoretical Chemistry, Roslagstullsbacken 15, Royal Institute of Technology, S-106 91 Stockholm (Sweden); Gel'mukhanov, Faris [Theoretical Chemistry, Roslagstullsbacken 15, Royal Institute of Technology, S-106 91 Stockholm (Sweden)

    2010-11-15T23:59:59.000Z

    The energy of the photoelectron experiences a red or blue Doppler shift when the molecule recedes from the detector or approaches him. This results in a broadening of the photoelectron line due to the translational thermal motion. However, the molecules also have rotational degrees of freedom and we show that the translational Doppler effect has its rotational counterpart. This rotational Doppler effect leads to an additional broadening of the spectral line of the same magnitude as the Doppler broadening caused by translational thermal motion. The rotational Doppler broadening as well as the rotational recoil broadening is sensitive to the molecular orbital from which the photoelectron is ejected. This broadening should be taken into account in analysis of x-ray photoemission spectra of super-high resolution and it can be directly observed using x-ray pump-probe spectroscopy.

  13. SPIN POLARIZED PHOTOELECTRON SPECTROSCOPY AS A PROBE OF MAGNETIC SYSTEMS.

    SciTech Connect (OSTI)

    JOHNSON, P.D.; GUNTHERODT, G.

    2006-11-01T23:59:59.000Z

    Spin-polarized photoelectron spectroscopy has developed into a versatile tool for the study of surface and thin film magnetism. In this chapter, we examine the methodology of the technique and its recent application to a number of different problems. We first examine the photoemission process itself followed by a detailed review of spin-polarization measurement techniques and the related experimental requirements. We review studies of spin polarized surface states, interface states and quantum well states followed by studies of the technologically important oxide systems including half-metallic transition metal oxides, ferromagnet/oxide interfaces and the antiferromagnetic cuprates that exhibit high Tc Superconductivity. We also discuss the application of high-resolution photoemission with spin resolving capabilities to the study of spin dependent self energy effects.

  14. Probing the hydrogen-bond network of water via time-resolved soft x-ray spectroscopy

    SciTech Connect (OSTI)

    Huse, Nils; Wen, Haidan; Nordlund, Dennis; Szilagyi, Erzsi; Daranciang, Dan; Miller, Timothy A.; Nilsson, Anders; Schoenlein, Robert W.; Lindenberg, Aaron M.

    2009-04-24T23:59:59.000Z

    We report time-resolved studies of hydrogen bonding in liquid H2O, in response to direct excitation of the O-H stretch mode at 3 mu m, probed via soft x-ray absorption spectroscopy at the oxygen K-edge. This approach employs a newly developed nanofluidic cell for transient soft x-ray spectroscopy in liquid phase. Distinct changes in the near-edge spectral region (XANES) are observed, and are indicative of a transient temperature rise of 10K following transient laser excitation and rapid thermalization of vibrational energy. The rapid heating occurs at constant volume and the associated increase in internal pressure, estimated to be 8MPa, is manifest by distinct spectral changes that differ from those induced by temperature alone. We conclude that the near-edge spectral shape of the oxygen K-edge is a sensitive probe of internal pressure, opening new possibilities for testing the validity of water models and providing new insight into the nature of hydrogen bonding in water.

  15. X-ray continuum emission spectroscopy from hot dense matter at Gbar pressures

    SciTech Connect (OSTI)

    Kraus, D., E-mail: dominik.kraus@berkeley.edu; Falcone, R. W. [Department of Physics, University of California, Berkeley, California 94720 (United States); Döppner, T.; Kritcher, A. L.; Bachmann, B.; Collins, G. W.; Hawreliak, J. A.; Landen, O. L.; Ma, T.; Le Pape, S.; Swift, D. C. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Chapman, D. A. [Plasma Physics Group, Radiation Physics Department, AWE plc, Reading RG7 4PR, United Kingdom and Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry CV4 7AL (United Kingdom); Glenzer, S. H. [SLAC National Accelerator Laboratory, Menlo Park, California 94309 (United States); Neumayer, P. [GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany)

    2014-11-15T23:59:59.000Z

    We have measured the time-resolved x-ray continuum emission spectrum of ?30 times compressed polystyrene created at stagnation of spherically convergent shock waves within the Gbar fundamental science campaign at the National Ignition Facility. From an exponential emission slope between 7.7 keV and 8.1 keV photon energy and using an emission model which accounts for reabsorption, we infer an average electron temperature of 375 ± 21 eV, which is in good agreement with HYDRA-1D simulations.

  16. SOFT X-RAY SPECTROSCOPY OF THE CYGNUS LOOP SUPERNOVA REMNANT

    SciTech Connect (OSTI)

    Oakley, Phil [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Ave., 37-582F, Cambridge, MA 02139 (United States)] [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Ave., 37-582F, Cambridge, MA 02139 (United States); McEntaffer, Randall [Department of Physics and Astronomy, Van Allen Hall, University of Iowa, Iowa City, IA 52242 (United States)] [Department of Physics and Astronomy, Van Allen Hall, University of Iowa, Iowa City, IA 52242 (United States); Cash, Webster, E-mail: Oakley@mit.edu [Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80309 (United States)] [Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80309 (United States)

    2013-03-20T23:59:59.000Z

    We present the results of a suborbital rocket flight whose scientific target was the Cygnus Loop Supernova Remnant. The payload consists of wire grid collimators, off-plane grating arrays, and gaseous electron multiplier (GEM) detectors. The system is designed for spectral measurements in the 17-107 A bandpass with a resolution up to {approx}60 ({lambda}/{Delta}{lambda}). The Extended X-ray Off-plane Spectrometer (EXOS) was launched on a Terrier-Black Brant rocket on 2009 November 13 from White Sands Missile Range and obtained 340 s of useable scientific data. The X-ray emission is dominated by O VII and O VIII, including the He-like O VII triplet at {approx}22 A. Another emission feature at {approx}45 A is composed primarily of Si XI and Si XII. The best-fit model to this spectrum is an equilibrium plasma model at a temperature of log(T) = 6.4 (0.23 keV).

  17. Suzaku X-Ray Spectroscopy of a Peculiar Hot Star in the Galactic Center Region

    E-Print Network [OSTI]

    Yoshiaki Hyodo; Masahiro Tsujimoto; Katsuji Koyama; Shogo Nishiyama; Tetsuya Nagata; Itsuki Sakon; Hiroshi Murakami; Hironori Matsumoto

    2007-12-03T23:59:59.000Z

    We present the results of a Suzaku study of a bright point-like source in the 6.7 keV intensity map of the Galactic center region. We detected an intense FeXXV 6.7 keV line with an equivalent width of ~1 keV as well as emission lines of highly ionized Ar and Ca from a spectrum obtained by the X-ray Imaging Spectrometer. The overall spectrum is described very well by a heavily absorbed (~2x10^{23}cm^{-2}) thin thermal plasma model with a temperature of 3.8+/-0.6 keV and a luminosity of ~3x10^{34} erg s^{-1} (2.0--8.0 keV) at 8 kpc. The absorption, temperature, luminosity, and the 6.7 keV line intensity were confirmed with the archived XMM-Newton data. The source has a very red (J-Ks=8.2 mag) infrared spectral energy distribution (SED), which was fitted by a blackbody emission of ~1000 K attenuated by a visual extinction of ~31 mag. The high plasma temperature and the large X-ray luminosity are consistent with a wind-wind colliding Wolf-Rayet binary. The similarity of the SED to those of the eponymous Quintuplet cluster members suggests that the source is a WC-type source.

  18. Atomic resolution mapping of the excited-state electronic structure of Cu2O with time-resolved x-ray absorption spectroscopy

    SciTech Connect (OSTI)

    Hillyard, P. W.; Kuchibhatla, S. V. N. T.; Glover, T. E.; Hertlein, M. P.; Huse, Nils; Nachimuthu, P.; Saraf, L. V.; Thevuthasan, S.; Gaffney, K. J.

    2010-05-02T23:59:59.000Z

    We have used time-resolved soft x-ray spectroscopy to investigate the electronic structure of optically excited cuprous oxide at the O K-edge and the Cu L3-edge. The 400 nm optical excitation shifts the Cu and O absorptions to lower energy, but does not change the integrated x-ray absorption significantly for either edge. The constant integrated x-ray absorption cross-section indicates that the conduction-band and valence-band edges have very similar Cu 3d and O 2p orbital contributions. The 2.1 eV optical band gap of Cu2O significantly exceeds the one eV shift in the Cu L3- and O K-edges absorption edges induced by optical excitation, demonstrating the importance of core-hole excitonic effects and valence electron screening in the x-ray absorption process.

  19. In operando observation system for electrochemical reaction by soft X-ray absorption spectroscopy with potential modulation method

    SciTech Connect (OSTI)

    Nagasaka, Masanari, E-mail: nagasaka@ims.ac.jp; Kosugi, Nobuhiro [Institute for Molecular Science, Myodaiji, Okazaki 444-8585 (Japan); The Graduate University for Advanced Studies, Myodaiji, Okazaki 444-8585 (Japan); Yuzawa, Hayato; Horigome, Toshio [Institute for Molecular Science, Myodaiji, Okazaki 444-8585 (Japan)

    2014-10-15T23:59:59.000Z

    In order to investigate local structures of electrolytes in electrochemical reactions under the same scan rate as a typical value 100 mV/s in cyclic voltammetry (CV), we have developed an in operando observation system for electrochemical reactions by soft X-ray absorption spectroscopy (XAS) with a potential modulation method. XAS spectra of electrolytes are measured by using a transmission-type liquid flow cell with built-in electrodes. The electrode potential is swept with a scan rate of 100 mV/s at a fixed photon energy, and soft X-ray absorption coefficients at different potentials are measured at the same time. By repeating the potential modulation at each fixed photon energy, it is possible to measure XAS of electrochemical reaction at the same scan rate as in CV. We have demonstrated successful measurement of the Fe L-edge XAS spectra of aqueous iron sulfate solutions and of the change in valence of Fe ions at different potentials in the Fe redox reaction. The mechanism of these Fe redox processes is discussed by correlating the XAS results with those at different scan rates.

  20. Auto-oligomerization and hydration of pyrrole revealed by x-ray absorption spectroscopy

    SciTech Connect (OSTI)

    Advanced Light Source; Schwartz, Craig P.; Uejio, Janel S.; Duffin, Andrew M.; England, Alice H.; Prendergast, David; Saykally, Richard J

    2009-05-29T23:59:59.000Z

    Near edge x-ray absorption fine structure (NEXAFS) spectra have been measured at the carbon and nitrogen K-edges of the prototypical aromatic molecule, pyrrole, both in the gas phase and when solvated in water, and compared with spectra simulated using a combination of classical molecular dynamics and first principles density functional theory in the excited state core hole approximation. The excellent agreement enabled detailed assignments. Pyrrole is highly reactive, particularly in water, and reaction products formed by the auto-oligomerization of pyrrole are identified. The solvated spectra have been measured at two different temperatures, indicating that the final states remain largely unaffected by both hydration and temperature. This is somewhat unexpected, since the nitrogen in pyrrole can donate a hydrogen bond to water.

  1. Bonding Structure of Phenylacetylene on Hydrogen-Terminated Si(111) and Si(100): Surface Photoelectron Spectroscopy Analysis and Ab Initio Calculations

    SciTech Connect (OSTI)

    M Kondo; T Mates; D Fischer; F Wudl; E Kramer

    2011-12-31T23:59:59.000Z

    Interfaces between phenylacetylene (PA) monolayers and two silicon surfaces, Si(111) and Si(100), are probed by X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy, and the results are analyzed using ab initio molecular orbital calculations. The monolayer systems are prepared via the surface hydrosilylation reaction between PA and hydrogen-terminated silicon surfaces. The following spectral features are obtained for both of the PA-Si(111) and PA-Si(100) systems: a broad {pi}-{pi}* shakeup peak at 292 eV (XPS), a broad first ionization peak at 3.8 eV (UPS), and a low-energy C 1s {yields} {pi}* resonance peak at 284.3 eV (NEXAFS). These findings are ascribed to a styrene-like {pi}-conjugated molecular structure at the PA-Si interface by comparing the experimental data with theoretical analysis results. A conclusion is drawn that the vinyl group can keep its {pi}-conjugation character on the hydrogen-terminated Si(100) [H:Si(100)] surface composed of the dihydride (SiH{sub 2}) groups as well as on hydrogen-terminated Si(111) having the monohydride (SiH) group. The formation mechanism of the PA-Si(100) interface is investigated within cluster ab initio calculations, and the possible structure of the H:Si(100) surface is discussed based on available data.

  2. Proceedings of the eighth international colloquium on ultraviolet and x-ray spectroscopy of astrophysical and laboratory plasmas (IAU colloquium 86)

    SciTech Connect (OSTI)

    Not Available

    1984-01-01T23:59:59.000Z

    This volume represents the Proceedings of the Eighth International Colloquium on Ultraviolet and X-Ray Spectroscopy of Astrophysical and Laboratory Plasmas. The aim of this series of colloquia has been to bring together workers in the fields of astrophysical spectroscopy, laboratory spectroscopy and atomic physics in order to exchange ideas and results on problems which are common to these different disciplines. In addition to the presented papers there was a poster paper session. (WRF)

  3. Non-matrix corrected organic sulfur determination by energy dispersive X-ray spectroscopy for western Kentucky coals and residues

    SciTech Connect (OSTI)

    Clark, C.P.; Freeman, G.B.; Hower, J.C.

    1984-01-01T23:59:59.000Z

    A method for non-matrix corrected organic sulfur analysis by energy dispersive X-ray spectroscopy has been developed using petroleum coke standards. Typically, electron beam microanalysis is a rapid, nondestructive analytical technique to quantitatively measure organic sulfur in coal. The results show good correlation to ASTM values for numerous well characterized coals with a wide range in total and pyritic sulfur content. This direct analysis is capable of reducing error commonly associated with the present ASTM method which relies on an indirect measure of organic sulfur by difference. The precision of the organic sulfur values determined in the present study is comparable to that obtained by ZAF matrix corrected microanalysis. The energy dispersive microanalysis is capable of measuring micro as well as bulk organic sulfur levels.

  4. Sulfur K-edge X-ray absorption spectroscopy as an experimental probe for S-nitroso proteins

    SciTech Connect (OSTI)

    Szilagyi, Robert K. [Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717 (United States)]. E-mail: Szilagyi@Montana.EDU; Schwab, David E. [Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717 (United States)

    2005-04-29T23:59:59.000Z

    X-ray absorption spectroscopy at the sulfur K-edge (2.4-2.6 keV) provides a sensitive and specific technique to identify S-nitroso compounds, which have significance in nitric oxide-based cell signaling. Unique spectral features clearly distinguish the S-nitroso-form of a cysteine residue from the sulfhydryl-form or from a methionine thioether. Comparison of the sulfur K-edge spectra of thiolate, thiol, thioether, and S-nitroso thiolate compounds indicates high sensitivity of energy positions and intensities of XAS pre-edge features as determined by the electronic environment of the sulfur absorber. A new experimental setup is being developed for reaching the in vivo concentration range of S-nitroso thiol levels in biological samples.

  5. Local versus global electronic properties of chalcopyrite alloys: X-ray absorption spectroscopy and ab initio calculations

    SciTech Connect (OSTI)

    Sarmiento-Pérez, Rafael; Botti, Silvana, E-mail: silvana.botti@univ-lyon1.fr [Institut Lumière Matière and ETSF, UMR5306 Université Lyon 1-CNRS, Université de Lyon, F-69622 Villeurbanne Cedex (France); Schnohr, Claudia S., E-mail: c.schnohr@uni-jena.de [Institut für Festkörperphysik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Lauermann, Iver [Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner Platz 1, 14109 Berlin (Germany); Rubio, Angel [Nano-Bio Spectroscopy Group and ETSF Scientific Development Centre, Departamento de Física de Materiales, Centro de Física de Materiales CSIC-MPC and DIPC, Universidad del País Vasco UPV/EHU, Avenida de Tolosa 72, E-20018 San Sebastián (Spain); Fritz Haber Institute, Max Planck Society, Faradayweg 4-6, 14195 Berlin (Germany); Johnson, Benjamin, E-mail: benjamin.johnson@alumni.tu-berlin.de [Fritz Haber Institute, Max Planck Society, Faradayweg 4-6, 14195 Berlin (Germany)

    2014-09-07T23:59:59.000Z

    Element-specific unoccupied electronic states of Cu(In, Ga)S{sub 2} were studied as a function of the In/Ga ratio by combining X-ray absorption spectroscopy with density functional theory calculations. The S absorption edge shifts with changing In/Ga ratio as expected from the variation of the band gap. In contrast, the cation edge positions are largely independent of composition despite the changing band gap. This unexpected behavior is well reproduced by our calculations and originates from the dependence of the electronic states on the local atomic environment. The changing band gap arises from a changing spatial average of these localized states with changing alloy composition.

  6. In-situ X-ray absorption spectroscopy analysis of capacity fade in nanoscale-LiCoO{sub 2}

    SciTech Connect (OSTI)

    Patridge, Christopher J. [NRC/NRL Cooperative Research Associate, U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Love, Corey T., E-mail: corey.love@nrl.navy.mil [Chemistry Division, Code 6113, U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Swider-Lyons, Karen E. [Chemistry Division, Code 6113, U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Twigg, Mark E. [Electronics Science and Technology Division, Code 6812, U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Ramaker, David E. [Chemistry Division, Code 6189, U.S. Naval Research laboratory, Washington, DC 20375 (United States)

    2013-07-15T23:59:59.000Z

    The local structure of nanoscale (?10–40 nm) LiCoO{sub 2} is monitored during electrochemical cycling utilizing in-situ X-ray absorption spectroscopy (XAS). The high surface area of the LiCoO{sub 2} nanoparticles not only enhances capacity fade, but also provides a large signal from the particle surface relative to the bulk. Changes in the nanoscale LiCoO{sub 2} metal-oxide bond lengths, structural disorder, and chemical state are tracked during cycling by adapting the delta mu (??) technique in complement with comprehensive extended X-ray absorption fine structure (EXAFS) modeling. For the first time, we use a ?? EXAFS method, and by comparison of the difference EXAFS spectra, extrapolate significant coordination changes and reduction of cobalt species with cycling. This combined approach suggests Li–Co site exchange at the surface of the nanoscale LiCoO{sub 2} as a likely factor in the capacity fade and irreversible losses in practical, microscale LiCoO{sub 2}. - Graphical abstract: Electrochemical cycling of Li-ion batteries has strong impact on the structure and integrity of the cathode active material particularly near the surface/electrolyte interface. In developing a new method, we have used in-situ X-ray absorption spectroscopy during electrochemical cycling of nanoscale LiCoO{sub 2} to track changes during charge and discharge and between subsequent cycles. Using difference spectra, several small changes in Co-O bond length, Co-O and Co-Co coordination, and site exchange between Co and Li sites can be tracked. These methods show promise as a new technique to better understand processes which lead to capacity fade and loss in Li-ion batteries. - Highlights: • A new method is developed to understand capacity fade in Li-ion battery cathodes. • Structural changes are tracked during Li intercalation/deintercalation of LiCoO{sub 2}. • Surface structural changes are emphasized using nanoscale-LiCoO{sub 2} and difference spectra. • Full multiple scattering calculations are used to support ?? analysis.

  7. X-ray absorption spectroscopy elucidates the impact of structural disorder on electron mobility in amorphous zinc-tin-oxide thin films

    SciTech Connect (OSTI)

    Siah, Sin Cheng, E-mail: siahsincheng@gmail.com, E-mail: buonassisi@mit.edu; Lee, Yun Seog; Buonassisi, Tonio, E-mail: siahsincheng@gmail.com, E-mail: buonassisi@mit.edu [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Lee, Sang Woon; Gordon, Roy G. [Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 (United States); Heo, Jaeyeong [Department of Materials Science and Engineering, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Shibata, Tomohiro; Segre, Carlo U. [Physics Department and CSRRI, Illinois Institute of Technology, Chicago, Illinois 606016 (United States)

    2014-06-16T23:59:59.000Z

    We investigate the correlation between the atomic structures of amorphous zinc-tin-oxide (a-ZTO) thin films grown by atomic layer deposition (ALD) and their electronic transport properties. We perform synchrotron-based X-ray absorption spectroscopy at the K-edges of Zn and Sn with varying [Zn]/[Sn] compositions in a-ZTO thin films. In extended X-ray absorption fine structure (EXAFS) measurements, signal attenuation from higher-order shells confirms the amorphous structure of a-ZTO thin films. Both quantitative EXAFS modeling and X-ray absorption near edge spectroscopy (XANES) reveal that structural disorder around Zn atoms increases with increasing [Sn]. Field- and Hall-effect mobilities are observed to decrease with increasing structural disorder around Zn atoms, suggesting that the degradation in electron mobility may be correlated with structural changes.

  8. advanced photoelectron spectroscopy: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    up to 11 303 VLF wave activity in the solar wind and the photoelectron effect in electric field measurements: Ulysses observations Physics Websites Summary: VLF wave activity in...

  9. Iron near absorption edge X-ray spectroscopy at aqueous-membrane interfaces

    SciTech Connect (OSTI)

    Wang, Wenjie; Kuzmenko, Ivan; Vaknin, David

    2014-01-01T23:59:59.000Z

    Employing synchrotron X-ray scattering, we systematically determine the absorption near-edge spectra (XANES) of iron in its ferrous (Fe2+) and ferric (Fe3+) states both as ions in aqueous solutions and as they bind to form a single layer to anionic templates that consist of carboxyl or phosphate groups at aqueous/vapor interfaces. While the XANES of bulk iron ions show that the electronic state and coordination of iron complexes in the bulk are isotropic, the interfacial bound ions show a signature of a broken inversion-symmetry environment. The XANES of Fe2+ and Fe3+ in the bulk possess distinct profiles however, upon binding they practically exhibit similar patterns. This indicates that both bound ions settle into a stable electronic and coordination configuration with an effective fractional valence (for example, Fe[2+nu]+, 0 < nu < 1) at charged organic templates. Such two dimensional properties may render interfacial iron, abundant in living organisms, a more efficient and versatile catalytic behavior.

  10. X-ray and EUV Spectroscopy of the Boundary Layer Emission of Nonmagnetic Cataclysmic Variables

    E-Print Network [OSTI]

    Christopher W. Mauche

    1997-09-11T23:59:59.000Z

    EUVE, ROSAT, and ASCA observations of the boundary layer emission of nonmagnetic cataclysmic variables (CVs) are reviewed. EUVE spectra reveal that the effective temperature of the soft component of high-Mdot nonmagnetic CVs is kT ~ 10-20 eV and that its luminosity is ~ 0.1-0.5 times the accretion disk luminosity. Although the EUV spectra are very complex and belie simple interpretation, the physical conditions of the boundary layer gas are constrained by emission lines of highly ionized Ne, Mg, Si, and Fe. ROSAT and ASCA spectra of the hard component of nonmagnetic CVs are satisfactorily but only phenomenologically described by multi-temperature thermal plasmas, and the constraints imposed on the physical conditions of this gas are limited by the relatively weak and blended lines. It is argued that significant progress in our understanding of the X-ray spectra of nonmagnetic CVs will come with future observations with XMM, AXAF, and Astro-E.

  11. Coupling MD Simulations and X-ray Absorption Spectroscopy to Study Ions in Solution

    SciTech Connect (OSTI)

    Marcos, E. Sanchez; Beret, E. C.; Martinez, J. M.; Pappalardo, R. R. [University of Seville, Dept. of Physical Chemistry (Spain); Ayala, R.; Munoz-Paez, A. [University of Seville, CSIC-ICMSE. Dept. of Inorganic Chemistry (Spain)

    2007-11-29T23:59:59.000Z

    The structure of ionic solutions is a key-point in understanding physicochemical properties of electrolyte solutions. Among the reduced number of experimental techniques which can supply direct information on the ion environment, X-ray Absorption techniques (XAS) have gained importance during the last decades although they are not free of difficulties associated to the data analysis leading to provide reliable structures. Computer simulations of ions in solution is a theoretical alternative to provide information on the solvation structure. Thus, the use of computational chemistry can increase the understanding of these systems although an accurate description of ionic solvation phenomena represents nowadays a significant challenge to theoretical chemistry. We present: (a) the assignment of features in the XANES spectrum to well defined structural motif in the ion environment, (b) MD-based evaluation of EXAFS parameters used in the fitting procedure to make easier the structural resolution, and (c) the use of the agreement between experimental and simulated XANES spectra to help in the choice of a given intermolecular potential for Computer Simulations. Chemical problems examined are: (a) the identification of the second hydration shell in dilute aqueous solutions of highly-charged cations, such as Cr{sup 3+}, Rh{sup 3+}, Ir{sup 3+}, (b) the invisibility by XAS of certain structures characterized by Computer Simulations but exhibiting high dynamical behavior and (c) the solvation of Br{sup -} in acetonitrile.

  12. Near-edge X-ray absorption fine-structure spectroscopy of naphthalene diimide-thiophene co-polymers

    SciTech Connect (OSTI)

    Gann, Eliot; McNeill, Christopher R., E-mail: christopher.mcneill@monash.edu [Department of Materials Engineering, Monash University, Wellington Road, Clayton, Victoria 3800 (Australia); Szumilo, Monika; Sirringhaus, Henning [Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom)] [Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Sommer, Michael [Institute of Macromolecular Chemistry, University of Freiburg, Stefan-Meier-Str. 31, 79104 Freiburg (Germany)] [Institute of Macromolecular Chemistry, University of Freiburg, Stefan-Meier-Str. 31, 79104 Freiburg (Germany); Maniam, Subashani; Langford, Steven J. [School of Chemistry, Monash University, Wellington Road, Clayton, Victoria 3800 (Australia)] [School of Chemistry, Monash University, Wellington Road, Clayton, Victoria 3800 (Australia); Thomsen, Lars [Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168 (Australia)] [Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168 (Australia)

    2014-04-28T23:59:59.000Z

    Near-edge X-ray absorption fine-structure (NEXAFS) spectroscopy is an important tool for probing the structure of conjugated polymer films used in organic electronic devices. High-performance conjugated polymers are often donor-acceptor co-polymers which feature a repeat unit with multiple functional groups. To facilitate better application of NEXAFS spectroscopy to the study of such materials, improved understanding of the observed NEXAFS spectral features is required. In order to examine how the NEXAFS spectrum of a donor-acceptor co-polymer relates to the properties of the sub-units, a series of naphthalene diimide-thiophene-based co-polymers have been studied where the nature and length of the donor co-monomer has been systematically varied. The spectra of these materials are compared with that of a thiophene homopolymer and naphthalene diimide monomer enabling peak assignment and the influence of inter-unit electronic coupling to be assessed. We find that while it is possible to attribute peaks within the ?* manifold as arising primarily due to the naphthalene diimide or thiophene sub-units, very similar dichroism of these peaks is observed indicating that it may not be possible to separately probe the molecular orientation of the separate sub-units with carbon K-edge NEXAFS spectroscopy.

  13. Suzaku Spectroscopy Study of Hard X-Ray Emission in the Arches Cluster

    E-Print Network [OSTI]

    M. Tsujimoto; Y. Hyodo; K. Koyama

    2006-11-03T23:59:59.000Z

    We present the results of a Suzaku study of the Arches cluster. A high S/N spectrum in the 3-12 keV band was obtained with the XIS. We found that the spectrum consists of a thermal plasma, a hard power-law tail, and two Gaussian lines. The plasma component (kT~2.2 keV) is established from the presence of CaXIX and FeXXV K alpha lines as well as the absence of FeXXVI K alpha line. The two Gaussian lines represent the K alpha and beta lines from iron at lower ionization stages. Both the line centers and the intensity ratio of these two lines are consistent with the neutral iron. The hard power-law tail (index~0.7) was found to have no pronounced iron K edge feature. In comparison with the published Chandra spectra, we conclude that the thermal component is from the ensemble of point-like sources plus thermal diffuse emission concentrated at the cluster center, while the Gaussian and the hard tail components are from the non-thermal diffuse emission extended in a larger scale. In the band-limited XIS images, the distribution of the 7.5-10.0 keV emission resembles that of the 6.4 keV emission. This strongly suggests that the power-law emission is related to the 6.4 and 7.1 keV lines in the underlying physics. We discuss two ideas to explain both the hard continuum and the lines: (1) X-ray photoionization that produces fluorescence lines and the Thomson scattering continuum and (2) non-thermal electron impact ionization of iron atoms and bremsstrahlung continuum. But whichever scenario is adopted, the photon or particle flux from the Arches cluster is too low to account for the observed line and continuum intensity.

  14. Characterization of Chain Molecular Assemblies in Long-Chain, Layered Silver Thiolates: A Joint Infrared Spectroscopy and X-ray Diffraction Study

    E-Print Network [OSTI]

    Parikh, Atul N.

    , and Theoretical DiVisions, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 ReceiVed: October 1, 1998 of infrared transmission spectroscopy and powder X-ray diffraction. The structural attributes elucidated. The three-dimensional network of 1D channels alternates between the chain layers. All the chain structural

  15. Photoelectron Spectroscopy of AInD-2 (n=3-15): Observation of...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AInD-2 (n3-15): Observation of Chemisorption and Physisorption of Dideuterium on Aluminum Cluster Photoelectron Spectroscopy of AInD-2 (n3-15): Observation of Chemisorption and...

  16. Start | View At a Glance | Author Index 220-1 Kinetics of Rapid Redox Processes at the Mineral/Water Interface Using Quick-Scanning X-Ray Absorption Spectroscopy

    E-Print Network [OSTI]

    Sparks, Donald L.

    at the Mineral/Water Interface Using Quick-Scanning X-Ray Absorption Spectroscopy (Q-XAS). See more from-situ synchrotron-based technique, quick scanning X-ray absorption spectroscopy (Q-XAS), at sub-second time scales

  17. X-ray absorption spectroscopy study of the local structure of heavy metal ions incorporated into electrodeposited nickel oxide films

    SciTech Connect (OSTI)

    Balasubramanian, M.; Melendres, C.A. [Argonne National Lab., IL (United States). Chemical Technology Div.] [Argonne National Lab., IL (United States). Chemical Technology Div.; Mansour, A.N. [Naval Surface Warfare Center, Bethesda, MD (United States). Carderock Div.] [Naval Surface Warfare Center, Bethesda, MD (United States). Carderock Div.

    1999-02-01T23:59:59.000Z

    The incorporation of heavy metal ions into simulated corrosion films has been investigated using spectroscopic and electrochemical techniques. The films were formed by electrodeposition of the appropriate oxide (hydroxide) onto a graphite substrate. Synchrotron X-ray absorption spectroscopy (XAS) was used to determine the structure and composition of the host oxide film, as well as the local structure of the impurity ion. Results on the incorporation of Ce and Sr into surface films of Ni(OH){sub 2} and NiOOH are reported. Cathodically deposited Ni(OH){sub 2} was found to be mainly in the alpha form while anodically prepared NiOOH showed the presence of Ni{sup +2} and Ni{sup +4}. Cerium incorporated into Ni(OH){sub 2} exists as mixed Ce{sup +3} and Ce{sup +4} phases; a Ce{sup +4} species was found when Ce was codeposited with NiOOH. The structure of the Ce{sup +4} phase in anodic films appears similar to a Ce(OH){sub 4} standard. However, XAS, X-ray diffraction, and laser Raman measurements indicate that the latter chemical formulation is probably incorrect and that the material is really a disordered form of hydrous cerium oxide. The local structure of this material is similar to CeO{sub 2} but has much higher structural disorder. The significance of this finding on the question of the structure of Ce-based corrosion inhibitors in aluminum oxide films is pointed out. Moreover, the authors found it possible to form pure Ce oxide (hydroxide) films on graphite by both cathodic and anodic electrodeposition; their structures have also been elucidated. Strontium incorporated into nickel oxide films consists of Sr{sup +2} which is coordinated to oxygen atoms and is likely to exist as small domains of coprecipitated material.

  18. Gas-phase ultraviolet photoelectron spectroscopy and molecular orbital calculations on transition metal carbonyls and nitrosyls

    E-Print Network [OSTI]

    Morris-Sherwood, Betty Jeanne

    1981-01-01T23:59:59.000Z

    GAS-PHASE ULTRAVIOLET PHOTOELECTRON SPECTROSCOPY AND MOLECULAR ORBITAL CALCULATIONS ON TRANSITION METAL CARBONYLS AND NITROSYLS A Thesis by BETTY JEANNE MORRIS-SHERWOOD Submitted to the Graduate College of Texas ARM Uni ver s i ty in partial... JEANNE MORRIS-SHERWOOD Approved as to sty1e and content by: (Chairman of Committee) (Member): (Niember) r / )g (Head of Department) December 1981 ABSTRACT Gas-Phas Ultraviolet Photoelectron Spectroscopy and Molecular Orbital Calculations...

  19. Broadband X-ray Imaging and Spectroscopy of the Crab Nebula and Pulsar with NuSTAR

    E-Print Network [OSTI]

    Madsen, Kristin K; Harrison, Fiona; An, Hongjun; Boggs, Steven; Christensen, Finn E; Craig, William W; Fryer, Chris L; Grefenstette, Brian W; Hailey, Charles J; Markwardt, Craig; Nynka, Melania; Stern, Daniel; Zoglauer, Andreas; Zhang, William

    2015-01-01T23:59:59.000Z

    We present broadband (3 -- 78 keV) NuSTAR X-ray imaging and spectroscopy of the Crab nebula and pulsar. We show that while the phase-averaged and spatially integrated nebula + pulsar spectrum is a power-law in this energy band, spatially resolved spectroscopy of the nebula finds a break at $\\sim$9 keV in the spectral photon index of the torus structure with a steepening characterized by $\\Delta\\Gamma\\sim0.25$. We also confirm a previously reported steepening in the pulsed spectrum, and quantify it with a broken power-law with break energy at $\\sim$12 keV and $\\Delta\\Gamma\\sim0.27$. We present spectral maps of the inner 100\\as\\ of the remnant and measure the size of the nebula as a function of energy in seven bands. These results find that the rate of shrinkage with energy of the torus size can be fitted by a power-law with an index of $\\gamma = 0.094\\pm 0.018$, consistent with the predictions of Kennel and Coroniti (1984). The change in size is more rapid in the NW direction, coinciding with the counter-jet w...

  20. Near-infrared photoluminescence and ligand K-edge x-ray absorption spectroscopies of AnO2Cl42-(An:u, NP, Pu)

    SciTech Connect (OSTI)

    Wilkerson, Marianne P [Los Alamos National Laboratory; Berg, John M [Los Alamos National Laboratory; Clark, David L [Los Alamos National Laboratory; Conradson, Steven D [Los Alamos National Laboratory; Hobart, David E [Los Alamos National Laboratory; Kozimor, Stosh A [Los Alamos National Laboratory; Scott, Brian L [Los Alamos National Laboratory

    2008-01-01T23:59:59.000Z

    We have used photoluminescence and X-ray absorption spectroscopies to investigate electronic structures and metal-ligand bonding of a series of An02CI/ ' (An = U, Np, Pu) compounds. Specifically, we will discuss time-resolved near-infrared emission spectra of crystalline Cs2U(An)02C14 (An = Np and Pu) both at 23 K and 75 K, as well as chlorine Kedge X-ray absorption spectra ofCs2An02CI4 (An = U, Np).

  1. The Electron-Phonon Interaction as Studied by Photoelectron Spectroscopy

    SciTech Connect (OSTI)

    D.W. Lynch

    2004-09-30T23:59:59.000Z

    With recent advances in energy and angle resolution, the effects of electron-phonon interactions are manifest in many valence-band photoelectron spectra (PES) for states near the Fermi level in metals.

  2. Distinct local structure of nanoparticles and nanowires of V{sub 2}O{sub 5} probed by x-ray absorption spectroscopy

    SciTech Connect (OSTI)

    Joseph, B.; Maugeri, L.; Bendele, M.; Saini, N. L., E-mail: Naurang.Saini@roma1.infn.it [Dipartimento di Fisica, Universitá di Roma “La Sapienza” - P. le Aldo Moro 2, 00185 Roma (Italy); Iadecola, A. [Dipartimento di Fisica, Universitá di Roma “La Sapienza” - P. le Aldo Moro 2, 00185 Roma (Italy) [Dipartimento di Fisica, Universitá di Roma “La Sapienza” - P. le Aldo Moro 2, 00185 Roma (Italy); Elettra, Sincrotrone Trieste, Strada Statale 14, Km 163.5, Basovizza, Trieste (Italy); Okubo, M.; Li, H.; Zhou, H. [National Institute of Advanced Industrial Science and Technology (AIST), Umezono 1-1-1, Tsukuba 305-8568 (Japan)] [National Institute of Advanced Industrial Science and Technology (AIST), Umezono 1-1-1, Tsukuba 305-8568 (Japan); Mizokawa, T. [Department of Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan) [Department of Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan); Department of Complexity Science and Engineering, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan)

    2013-12-16T23:59:59.000Z

    We have used V K-edge x-ray absorption spectroscopy to study local structures of bulk, nanoparticles and nanowires of V{sub 2}O{sub 5}. The extended x-ray absorption fine structure measurements show different local displacements in the three morphologically different V{sub 2}O{sub 5} samples. It is found that the nanowires have a significantly ordered chain structure in comparison to the V{sub 2}O{sub 5} bulk. In contrast, nanoparticles have larger interlayer disorder. The x-ray absorption near-edge structure spectra show different electronic structure that appears to be related with the local atomic disorder in the three V{sub 2}O{sub 5} samples.

  3. Broadband spectroscopy of the eclipsing high mass X-ray binary 4U 1700-37 with Suzaku

    E-Print Network [OSTI]

    Jaisawal, Gaurava K

    2015-01-01T23:59:59.000Z

    We present the results obtained from broadband spectroscopy of the high mass X-ray binary 4U 1700-37 using data from a Suzaku observation in 2006 September 13-14 covering 0.29-0.72 orbital phase range. The light curves showed significant and rapid variation in source flux during entire observation. We did not find any signature of pulsations in the light curves. However, a quasi-periodic oscillation at ~20 mHz was detected in the power density spectrum of the source. The 1-70 keV spectrum was fitted with various continuum models. However, we found that the partially absorbed high energy cutoff power-law and Negative and Positive power-law with Exponential cutoff (NPEX) models described the source spectrum well. Iron emission lines at 6.4 keV and 7.1 keV were detected in the source spectrum. An absorption like feature at ~39 keV was detected in the residuals while fitting the data with NPEX model. Considering the feature as cyclotron absorption line, the surface magnetic field of the neutron star was estimated...

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

    SciTech Connect (OSTI)

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

    2014-02-04T23:59:59.000Z

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

  5. Real-time x-ray absorption spectroscopy of uranium, iron, and manganese in contaminated sediments during bioreduction

    SciTech Connect (OSTI)

    Tokunaga, Tetsu; Tokunaga, T.K.; Wan, J.; Kim, Y.; Sutton, S.R.; Newville, M.; Lanzirotti, A.; Rao, W.

    2008-01-15T23:59:59.000Z

    The oxidation status of uranium in sediments is important because the solubility of this toxic and radioactive element is much greater for U(VI) than for U(IV) species. Thus, redox manipulation to promote precipitation of UO{sub 2} is receiving interest as a method to remediate U-contaminated sediments. Presence of Fe and Mn oxides in sediments at much higher concentrations than U requires understanding of their redox status as well. This study was conducted to determine changes in oxidation states of U, Fe, and Mn in U-contaminated sediments from Oak Ridge National Laboratory. Oxidation states of these elements were measured in real-time and nondestructively using X-ray absorption spectroscopy, on sediment columns supplied with synthetic groundwater containing organic carbon (OC, 0, 3, 10, 30 and 100 mM OC as lactate) for over 400 days. In sediments supplied with OC {ge} 30 mM, 80% of the U was reduced to U(IV), with transient reoxidation at about 150 days. Mn(III,IV) oxides were completely reduced to Mn(II) in sediments infused with OC {ge} 3 mM. However, Fe remained largely unreduced in all sediment columns, showing that Fe(III) can persist as an electron acceptor in reducing sediments over long times. This result in combination with the complete reduction of all other potential electron acceptors supports the hypothesis that the reactive Fe(III) fraction was responsible for reoxidizing U(IV).

  6. An x-ray absorption near-edge spectroscopy study of the oxidation state of chromium in electrodeposited oxide films.

    SciTech Connect (OSTI)

    Balasubramanian, M.; Melendres, C. A.; Chemical Engineering

    1999-01-01T23:59:59.000Z

    The oxidation state of chromium incorporated into simulated corrosion films of nickel has been investigated using the technique of 'in situ' X-ray Absorption Near-Edge Spectroscopy (XANES). The films were prepared by electrochemical deposition of the appropriate oxide (hydroxide) onto a graphite substrate. Cathodic deposition from a 0.01 M Cr(NO{sub 3}){sub 3} solution at constant current results in a Cr{sup 3+} oxide (hydroxide) film. Deposition from a 0.01 M K{sub 2}CrO{sub 4} solution produces a film which is predominantly Cr{sup 3+} but with some Cr{sup 6+}. This material is air-sensitive and the ratio of Cr{sup 6+} to Cr{sup 3+} increases with time of exposure to ambient. Cathodic codeposition of Cr{sup 3+} with nickel hydroxide from Cr(NO{sub 3}){sub 3} solution results in a film with chromium in the 3+ oxidation state. On the other hand, cathodic codeposition from a Cr{sup 6+} solution of K{sub 2}CrO{sub 4} with nickel hydroxide leads to a film containing Cr{sup 6+}.

  7. Development of Palladium L-Edge X-Ray Absorption Spectroscopy And Its Application for Chloropalladium Complexes

    SciTech Connect (OSTI)

    Boysen, R.B.; Szilagyi, R.K.

    2009-05-12T23:59:59.000Z

    X-ray absorption spectroscopy (XAS) is a synchrotron-based experimental technique that provides information about geometric and electronic structures of transition metal complexes. Combination of metal L-edge and ligand K-edge XAS has the potential to define the complete experimental ground state electronic structures for metal complexes with unoccupied d manifolds. We developed a quantitative treatment for Pd L-edge spectroscopy on the basis of the well-established chlorine K-edge XAS for a series of chloropalladium complexes that are pre-catalysts in various organic transformations. We found that Pd-Cl bonds are highly covalent, such as 24 {+-} 2%, 34 {+-} 3%, and 48 {+-} 4% chloride 3p character for each Pd-Cl bond in [PdCl{sub 4}]{sup 2-}, [PdCl{sub 6}]{sup 2-}, and PdCl{sub 2}, respectively. Pd(2p {yields} 4d) transition dipole integrals of 20.8 (SSRL)/16.9 (ALS) eV and 14.1 (SSRL)/11.9 (ALS) eV were determined using various combinations of L-edges for Pd(II) and Pd(IV), respectively. Application of metal-ligand covalency and transition dipole integrals were demonstrated for the example of bridging chloride ligands in PdCl{sub 2}. Our work lays the foundation for extending the quantitative treatment to other catalytically important ligands, such as phosphine, phosphite, olefin, amine, and alkyl in order to correlate the electronic structures of palladium complexes with their catalytic activity.

  8. Transition state spectroscopy of the I + HI reaction in clusters: Photoelectron spectroscopy of (n = 115)IHI-- Ar

    E-Print Network [OSTI]

    Neumark, Daniel M.

    Transition state spectroscopy of the I + HI reaction in clusters: Photoelectron spectroscopy of (n Article on the web 4th June 2001 We have investigated eects of solvation on the transition state and hindered rotational motions of the transition state complex IHI. The shifts in electron binding energy

  9. Resonant soft X-ray emission spectroscopy of vanadium oxides andrelated compounds

    SciTech Connect (OSTI)

    Schmitt, Thorsten

    2004-11-01T23:59:59.000Z

    In today's information world, bits of data are processed by semiconductor chips, and stored in the magnetic disk drives. But tomorrow's information technology may see magnetism (spin) and semiconductivity (charge) combined in one ''spintronic'' device that exploits both charge and ''spin'' to carry data (the best of two worlds). Spintronic devices such as spin valve transistors, spin light emitting diodes, non-volatile memory, logic devices, optical isolators and ultra-fast optical switches are some of the areas of interest for introducing the ferromagnetic properties at room temperature in a semiconductor to make it multifunctional. The potential advantages of such spintronic devices will be higher speed, greater efficiency, and better stability at a reduced power consumption. This Thesis contains two main topics: In-depth understanding of magnetism in Mn doped ZnO, and our search and identification of at least six new above room temperature ferromagnetic semiconductors. Both complex doped ZnO based new materials, as well as a number of nonoxides like phosphides, and sulfides suitably doped with Mn or Cu are shown to give rise to ferromagnetism above room temperature. Some of the highlights of this work are discovery of room temperature ferromagnetism in: (1) ZnO:Mn (paper in Nature Materials, Oct issue, 2003); (2) ZnO doped with Cu (containing no magnetic elements in it); (3) GaP doped with Cu (again containing no magnetic elements in it); (4) Enhancement of Magnetization by Cu co-doping in ZnO:Mn; and (5) CdS doped with Mn, and a few others not reported in this thesis. We discuss in detail the first observation of ferromagnetism above room temperature in the form of powder, bulk pellets, in 2-3 {micro}m thick transparent pulsed laser deposited films of the Mn (< 4 at.%) doped ZnO. High-resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS) spectra recorded from 2 to 200nm areas showed homogeneous distribution of Mn substituting for Zn a 2{sup +} state in the ZnO lattice. Ferromagnetic Resonance (FMR) technique is used to confirm the existence of ferromagnetic ordering at temperatures as high as 425K. The ab initio calculations were found to be consistent with the observation of ferromagnetism arising from fully polarized Mn 2{sup +} state. The key to observed room temperature ferromagnetism in this system is the low temperature processing, which prevents formation of clusters, secondary phases and the host ZnO from becoming n-type. The electronic structure of the same Mn doped ZnO thin films studied using XAS, XES and RIXS. revealed a strong hybridization between Mn 3d and O 2p states, which is an important characteristic of a Dilute magnetic Semiconductor (DMS). It is shown that the various processing conditions like sintering temperature, dopant concentration and the properties of precursors used for making of DMS have a great influence on the final properties. Use of various experimental techniques to verify the physical properties, and to understand the mechanism involved to give rise to ferromagnetism is presented. Methods to improve the magnetic moment in Mn doped ZnO are also described. New promising DMS materials (such as Cu doped ZnO are explored). The demonstrated new capability to fabricate powder, pellets, and thin films of room temperature ferromagnetic semiconductors thus makes possible the realization of a wide range of complex elements for a variety of new multifunctional phenomena related to Spintronic devices as well as magneto-optic components.

  10. Investigating Silicon-Based Photoresists with Coherent Anti-Stokes Raman Scattering and X-ray Micro-spectroscopy

    E-Print Network [OSTI]

    Caster, Allison G.

    2010-01-01T23:59:59.000Z

    LIGHT (X- RAYS , EUV, ULTRAFAST PULSES ), OR HEAT . T HEthe “on” time of an ultrafast pulse is referred to as thepeak-power of the ultrafast pulses, purely electronic four-

  11. Speciation of Lead in a Mixed Soil Component System Using X-ray Absorption Fine Structure Spectroscopy

    E-Print Network [OSTI]

    Sparks, Donald L.

    Speciation of Lead in a Mixed Soil Component System Using X-ray Absorption Fine Structure (XAFS). Lead concentrations of 6000, 18000, and 29000 µg Pb/g solid were reacted with soil components

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

    E-Print Network [OSTI]

    Bruccoleri, Alexander Robert

    2013-01-01T23:59:59.000Z

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

  13. Influence of the cobalt particle size in the CO hydrogenation reaction studied by in situ X-ray absorption spectroscopy

    E-Print Network [OSTI]

    Herranz, Tirma

    2010-01-01T23:59:59.000Z

    Cobalt, nanoparticles, Fischer-Tropsch, X-ray absorption (oxides [5] and Fischer-Tropsch (FT) synthesis [6,7]. Itswhich is inactive for Fischer-Tropsch synthesis. This oxide

  14. A Fast, Versatile Nanoprobe for Complex Materials: The Sub-micron Resolution X-ray Spectroscopy Beamline at NSLS-II (491st Brookhaven Lecture)

    SciTech Connect (OSTI)

    Thieme, Juergen [BNL Photon Sciences Directorate

    2014-02-06T23:59:59.000Z

    Time is money and for scientists who need to collect data at research facilities like Brookhaven Lab’s National Synchrotron Light Source (NSLS), “beamtime” can be a precious commodity. While scanning a complex material with a specific technique and standard equipment today would take days to complete, researchers preparing to use brighter x-rays and the new sub-micron-resolution x-ray spectroscopy (SRX) beamline at the National Synchrotron Light Source II (NSLS-II) could scan the same sample in greater detail with just a few hours of beamtime. Talk about savings and new opportunities for researchers! Users will rely on these tools for locating trace elements in contaminated soils, developing processes for nanoparticles to deliver medical treatments, and much more. Dr. Thieme explains benefits for next-generation research with spectroscopy and more intense x-rays at NSLS-II. He discusses the instrumentation, features, and uses for the new SRX beamline, highlighting its speed, adjustability, and versatility for probing samples ranging in size from millimeters down to the nanoscale. He will talk about complementary beamlines being developed for additional capabilities at NSLS-II as well.

  15. Microgap x-ray detector

    DOE Patents [OSTI]

    Wuest, C.R.; Bionta, R.M.; Ables, E.

    1994-05-03T23:59:59.000Z

    An x-ray detector is disclosed which provides for the conversion of x-ray photons into photoelectrons and subsequent amplification of these photoelectrons through the generation of electron avalanches in a thin gas-filled region subject to a high electric potential. The detector comprises a cathode (photocathode) and an anode separated by the thin, gas-filled region. The cathode may comprise a substrate, such a beryllium, coated with a layer of high atomic number material, such as gold, while the anode can be a single conducting plane of material, such as gold, or a plane of resistive material, such as chromium/silicon monoxide, or multiple areas of conductive or resistive material, mounted on a substrate composed of glass, plastic or ceramic. The charge collected from each electron avalanche by the anode is passed through processing electronics to a point of use, such as an oscilloscope. 3 figures.

  16. Microgap x-ray detector

    DOE Patents [OSTI]

    Wuest, Craig R. (Danville, CA); Bionta, Richard M. (Livermore, CA); Ables, Elden (Livermore, CA)

    1994-01-01T23:59:59.000Z

    An x-ray detector which provides for the conversion of x-ray photons into photoelectrons and subsequent amplification of these photoelectrons through the generation of electron avalanches in a thin gas-filled region subject to a high electric potential. The detector comprises a cathode (photocathode) and an anode separated by the thin, gas-filled region. The cathode may comprise a substrate, such a beryllium, coated with a layer of high atomic number material, such as gold, while the anode can be a single conducting plane of material, such as gold, or a plane of resistive material, such as chromium/silicon monoxide, or multiple areas of conductive or resistive material, mounted on a substrate composed of glass, plastic or ceramic. The charge collected from each electron avalanche by the anode is passed through processing electronics to a point of use, such as an oscilloscope.

  17. Delocalization and occupancy effects of 5f orbitals in plutonium intermetallics using L3-edge resonant X-ray emission spectroscopy

    SciTech Connect (OSTI)

    Booth, C. H.; Medling, S. A.; Jiang, Yu; Bauer, E. D.; Tobash, P. H.; Mitchell, J. N.; Veirs, D. K.; Wall, M. A.; Allen, P. G.; Kas, J. J.; Sokaras, D.; Nordlund, D.; Weng, T.-C.

    2014-06-24T23:59:59.000Z

    Although actinide (An) L3 -edge X-ray absorption near-edge structure (XANES) spectroscopy has been very effective in determining An oxidation states in insulating, ionically bonded materials, such as in certain coordination compounds and mineral systems, the technique fails in systems featuring more delocalized 5f orbitals, especially in metals. Recently, actinide L3-edge resonant X-ray emission spec- troscopy (RXES) has been shown to be an effective alternative. This technique is further demonstrated here using a parameterized partial unoccupied density of states method to quantify both occupancy and delocalization of the 5f orbital in ?-Pu, ?-Pu, PuCoGa5 , PuCoIn5 , and PuSb2. These new results, supported by FEFF calculations, highlight the effects of strong correlations on RXES spectra and the technique?s ability to differentiate between f-orbital occupation and delocalization.

  18. Spectroscopy of M-shell x-ray transitions in Zn-like through Co-like W

    SciTech Connect (OSTI)

    Clementson, J; Beiersdorfer, P; Brown, G V; Gu, M F

    2009-07-08T23:59:59.000Z

    The M-shell x-ray emission of highly charged tungsten ions has been investigated at the Livermore electron beam ion trap facility. Using the SuperEBIT electron beam ion trap and a NASA x-ray calorimeter array, transitions connecting the ground configurations in the 1500-3600 eV spectral range of zinc-like W{sup 44+} through cobalt-like W{sup 47+} have been measured. The measured spectra are compared with theoretical line positions and emissivities calculated using the FAC code.

  19. Probing temporal evolution of extreme ultraviolet assisted contamination on Ru mirror by x-ray photoelectron spectroscopy

    E-Print Network [OSTI]

    Harilal, S. S.

    of hydrocarbons8 and the oxidation of the near sur- face atomic layers of Ru eventually lead to the degradation and oxidation of the Ru mirror surface, and the corresponding impact on reflectivity were studied. In particular analyses show a slight increase in Ru oxide, whereas the concentration of water molecules decreases

  20. In situ x-ray photoelectron spectroscopy studies of gas/solid interfaces at near-ambient conditions

    E-Print Network [OSTI]

    Bluhm, Hendrik; Havecker, Michael; Knop-Gericke, Axel; Kiskinova, Maya; Schlogl, Robert; Salmeron, Miquel

    2008-01-01T23:59:59.000Z

    now operating at BESSY (Berliner Elektronenspeicherring -of 0.3 mm (ALS) and 1 mm (BESSY), which allow pressures ofHB Comment [TP8]: What does BESSY stand for? SEE TEXT - HB

  1. In situ x-ray photoelectron spectroscopy studies of gas/solid interfaces at near-ambient conditions

    E-Print Network [OSTI]

    Bluhm, Hendrik; Havecker, Michael; Knop-Gericke, Axel; Kiskinova, Maya; Schlogl, Robert; Salmeron, Miquel

    2008-01-01T23:59:59.000Z

    of the synchrotron-based HP-XPS instruments at BESSY and theBESSY (Berliner Elektronenspeicherring - Gesellschaft für Synchrotronstrahlung m.b.H. , the Berlin 3 rd generation synchrotron

  2. Carbon contamination and oxidation of Au surfaces under extreme ultraviolet radiation: An x-ray photoelectron spectroscopy study

    E-Print Network [OSTI]

    Harilal, S. S.

    Carbon contamination and oxidation of Au surfaces under extreme ultraviolet radiation: An x 2012) Extreme ultraviolet (EUV) radiation-induced carbon contamination and oxidation of Au surfaces modification during EUV exposure. XPS analysis showed that total carbon contamination (C 1s peak

  3. The solvation of Cl , Br , and I in acetonitrile clusters: Photoelectron spectroscopy and molecular dynamics simulations

    E-Print Network [OSTI]

    Perera, Lalith

    The solvation of Cl , Br , and I in acetonitrile clusters: Photoelectron spectroscopy and molecular in acetonitrile clusters CH3CN n with n 1­33, 1­40, and 1­55, respectively, taken with 7.9 eV photon energy. Anion simulations of halide­acetonitrile clusters reproduce the measured stabilization energies and generate full

  4. angled-resolved photoelectron spectroscopy: Topics by E-print...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    profile and nitrogen chemical bonding states,6-9,11,13,17,18 secondary ion mass spectrometry SIMS ,14 Auger electron spectroscopy,19,20 nuclear reaction analysis NRA ,21 medium...

  5. angle-resolved photoelectron spectroscopies: Topics by E-print...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    profile and nitrogen chemical bonding states,6-9,11,13,17,18 secondary ion mass spectrometry SIMS ,14 Auger electron spectroscopy,19,20 nuclear reaction analysis NRA ,21 medium...

  6. angle-resolved photoelectron spectroscopy: Topics by E-print...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    profile and nitrogen chemical bonding states,6-9,11,13,17,18 secondary ion mass spectrometry SIMS ,14 Auger electron spectroscopy,19,20 nuclear reaction analysis NRA ,21 medium...

  7. Time-resolved x-ray absorption spectroscopy of photoinduced insulator-metal transition in a colossal magnetoresistive manganite

    SciTech Connect (OSTI)

    Rini, M.; Tobey, R.; Wall, S.; Zhu, Y.; Tomioka, Y.; Tokura, Y.; Cavalleri, A.; Schoenlein, R.W.

    2008-08-01T23:59:59.000Z

    We studied the ultrafast insulator-metal transition in a manganite by means of picosecond X-ray absorption at the O K- and Mn L-edges, probing photoinduced changes in O-2p and Mn-3d electronic states near the Fermi level.

  8. NuSTAR STUDY OF HARD X-RAY MORPHOLOGY AND SPECTROSCOPY OF PWN G21.5–0.9

    E-Print Network [OSTI]

    Nynka, Melania

    We present NuSTAR high-energy X-ray observations of the pulsar wind nebula (PWN)/supernova remnant G21.5–0.9. We detect integrated emission from the nebula up to ~40 keV, and resolve individual spatial features over a broad ...

  9. Soft x-ray spectroscopy beam line on the NSLS Xl undulator: Optical design and first performance tests

    E-Print Network [OSTI]

    Homes, Christopher C.

    generationof soft x-ray undulator beam lines which will figure prominently at new synchrotron radiation facilities such as ALS, ELETTRA and BESSY II. During the first performancetestsabsorption spectra of simple-ray region. 1. INTRODUCTION The next generationof synchrotron radiation (SR) fa- cilities servingthe soft x

  10. Journal of Electron Spectroscopy and Related Phenomena 144147 (2005) 259269 Soft X-ray spectromicroscopy of biological

    E-Print Network [OSTI]

    Hitchcock, Adam P.

    in the case of electron beam based techniques; radiation damage in the case of electron microscopy; lack. This requires a source of bright, continu- ouslytunablesoftX-rays(50­2000 eV),andthussynchrotron radiation spatial reso- lution in the case of IR, NMR and optical techniques; inabil- ity to couple to wet specimens

  11. Bandpass x-ray diode and x-ray multiplier detector

    DOE Patents [OSTI]

    Wang, C.L.

    1982-09-27T23:59:59.000Z

    An absorption-edge of an x-ray absorption filter and a quantum jump of a photocathode determine the bandpass characteristics of an x-ray diode detector. An anode, which collects the photoelectrons emitted by the photocathode, has enhanced amplification provided by photoelectron-multiplying means which include dynodes or a microchannel-plate electron-multiplier. Suppression of undesired high frequency response for a bandpass x-ray diode is provided by subtracting a signal representative of energies above the passband from a signal representative of the overall response of the bandpass diode.

  12. Conduction-band electronic states of YbInCu{sub 4} studied by photoemission and soft x-ray absorption spectroscopies

    SciTech Connect (OSTI)

    Utsumi, Yuki; Kurihara, Hidenao; Maso, Hiroyuki; Tobimatsu, Komei [Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan); Sato, Hitoshi; Shimada, Kenya; Namatame, Hirofumi [Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046 (Japan); Hiraoka, Koichi [Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577 (Japan); Kojima, Kenichi [Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima 739-8521 (Japan); Ohkochi, Takuo; Fujimori, Shin-ichi; Takeda, Yukiharu; Saitoh, Yuji [Synchrotron Radiation Research Center, Japan Atomic Energy Agency, Hyogo 679-5148 (Japan); Mimura, Kojiro [Graduate School of Engineering, Osaka Prefecture University, Sakai 599-8531 (Japan); Ueda, Shigenori; Yamashita, Yoshiyuki; Yoshikawa, Hideki; Kobayashi, Keisuke [NIMS Beamline Station at SPring-8, National Institute for Materials Science, Hyogo 679-5148 (Japan); Oguchi, Tamio [ISIR, Osaka University, Ibaraki 567-0047 (Japan); Taniguchi, Masaki [Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan); Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046 (Japan)

    2011-09-15T23:59:59.000Z

    We have studied conduction-band (CB) electronic states of a typical valence-transition compound YbInCu{sub 4} by means of temperature-dependent hard x-ray photoemission spectroscopy (HX-PES) of the Cu 2p{sub 3/2} and In 3d{sub 5/2} core states taken at h{nu}=5.95 keV, soft x-ray absorption spectroscopy (XAS) of the Cu 2p{sub 3/2} core absorption region around h{nu}{approx}935 eV, and soft x-ray photoemission spectroscopy (SX-PES) of the valence band at the Cu 2p{sub 3/2} absorption edge of h{nu}=933.0 eV. With decreasing temperature below the valence transition at T{sub V}=42 K, we have found that (1) the Cu 2p{sub 3/2} and In 3d{sub 5/2} peaks in the HX-PES spectra exhibit the energy shift toward the lower binding-energy side by {approx}40 and {approx}30 meV, respectively, (2) an energy position of the Cu 2p{sub 3/2} main absorption peak in the XAS spectrum is shifted toward higher photon-energy side by {approx}100 meV, with an appearance of a shoulder structure below the Cu 2p{sub 3/2} main absorption peak, and (3) an intensity of the Cu L{sub 3}VV Auger spectrum is abruptly enhanced. These experimental results suggest that the Fermi level of the CB-derived density of states is shifted toward the lower binding-energy side. We have described the valence transition in YbInCu{sub 4} in terms of the charge transfer from the CB to Yb 4f states.

  13. High-Dispersion Spectroscopy of the X-Ray Transient RXTE J0421+560 (= CI Cam) during Outburst

    E-Print Network [OSTI]

    Edward L. Robinson; Inese I. Ivans; William F. Welsh

    2001-10-04T23:59:59.000Z

    We obtained high dispersion spectra of CI Cam, the optical counterpart of XTE J0421+560, two weeks after the peak of its short outburst in 1998 April. The optical counterpart is a supergiant B[e] star emitting a two-component wind. The cool wind (the source of narrow emission lines of neutral and ionized metals) has a velocity of 32 km/s and a temperature near 8000 K. Dense and roughly spherical, it fills the space around the sgB[e] star, and, based on the size of an infrared-emitting dust shell around the system, extends to a radius between 13 - 50 AU. It carries away mass at a high rate, Mdot > 10^(-6) solar masses per year. The hot wind has a velocity in excess of 2500 km/s and a temperature of 1.7 +/-0.3 x 10^4 K. From UV spectra of CI Cam obtained in 2000 March with Hubble Space Telescope, we derive a differential extinction E(B-V) = 0.85 +/- 0.05. We derive a distance to CI Cam > 5 kpc. Based on this revised distance, the X-ray luminosity at the peak of the outburst was L(2-25 keV) > 3.0 x 10^38 erg/s, making CI Cam one of the most luminous X-ray transients. The ratio of quiescent to peak luminosity in the 2 - 25 keV band is < 1.7 x 10^(-6). The compact star in CI Cam is immersed in the dense circumstellar wind from the sgB[e] star and burrows through the wind producing little X-ray emission except for rare transient outbursts. This picture (a compact star traveling in a wide orbit through the dense circumstellar envelope of a sgB[e] star, occasionally producing transient X-ray outbursts) makes CI Cam unique among the known X-ray binaries. Strong circumstantial evidence suggests that the compact object is a black hole, not a neutron star. We speculate that the X-ray outburst was short because the accretion disk around the compact star is fed from a stellar wind and is smaller than disks fed by Roche-lobe overflow.

  14. Photoelectron Spectroscopy under Ambient Pressure and Temperature Conditions

    SciTech Connect (OSTI)

    Ogletree, D. Frank; Bluhm, Hendrik; Hebenstreit, Eleonore B.; Salmeron, Miquel

    2009-02-27T23:59:59.000Z

    We describe the development and applications of novel instrumentation for photoemission spectroscopy of solid or liquid surfaces in the presence of gases under ambient conditions or pressure and temperature. The new instrument overcomes the strong scattering of electrons in gases by the use of an aperture close to the surface followed by a differentially-pumped electrostatic lens system. In addition to the scattering problem, experiments in the presence of condensed water or other liquids require the development of special sample holders to provide localized cooling. We discuss the first two generations of Ambient Pressure PhotoEmission Spectroscopy (APPES) instruments developed at synchrotron light sources (ALS in Berkeley and BESSY in Berlin), with special focus on the Berkeley instruments. Applications to environmental science and catalytic chemical research are illustrated in two examples.

  15. Interaction of methanol and water on MgO,,100... studied by ultraviolet photoelectron and metastable impact electron spectroscopies

    E-Print Network [OSTI]

    Goodman, Wayne

    Interaction of methanol and water on MgO,,100... studied by ultraviolet photoelectron; accepted 27 October 1998 The coadsorption of methanol (CH3OH) and water (D2O) on the MgO 100 /Mo 100 photoelectron spectroscopy UPS HeI , and by thermal programmed desorption TPD . Methanol wets the MgO surface

  16. Double-core excitations in formamide can be probed by X-ray double-quantum-coherence spectroscopy

    SciTech Connect (OSTI)

    Zhang Yu; Healion, Daniel; Biggs, Jason D.; Mukamel, Shaul [Department of Chemistry, University of California, 450 Rowland Hall, Irvine, California 92697 (United States)

    2013-04-14T23:59:59.000Z

    The attosecond, time-resolved X-ray double-quantum-coherence four-wave mixing signals of formamide at the nitrogen and oxygen K-edges are simulated using restricted excitation window time-dependent density functional theory and the excited core hole approximation. These signals, induced by core exciton coupling, are particularly sensitive to the level of treatment of electron correlation, thus providing direct experimental signatures of electron and core-hole many-body effects and a test of electronic structure theories.

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

    SciTech Connect (OSTI)

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

    2014-05-15T23:59:59.000Z

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

  18. NuSTAR and Suzaku X-ray Spectroscopy of NGC 4151: Evidence for Reflection from the Inner Accretion Disk

    E-Print Network [OSTI]

    Keck, M L; Ballantyne, D R; Bauer, F; Boggs, S E; Christensen, F E; Craig, W W; Dauser, T; Elvis, M; Fabian, A C; Fuerst, F; García, J; Grefenstette, B W; Hailey, C J; Harrison, F A; Madejski, G; Marinucci, A; Matt, G; Reynolds, C S; Stern, D; Walton, D J; Zoghbi, A

    2015-01-01T23:59:59.000Z

    We present X-ray timing and spectral analyses of simultaneous 150 ks Nuclear Spectroscopic Telescope Array (NuSTAR) and Suzaku X-ray observations of the Seyfert 1.5 galaxy NGC 4151. We disentangle the continuum emission, absorption, and reflection properties of the active galactic nucleus (AGN) by applying inner accretion disk reflection and absorption-dominated models. With a time-averaged spectral analysis, we find strong evidence for relativistic reflection from the inner accretion disk. We find that relativistic emission arises from a highly ionized inner accretion disk with a steep emissivity profile, which suggests an intense, compact illuminating source. We find a preliminary, near-maximal black hole spin a>0.9 accounting for statistical and systematic modeling errors. We find a relatively moderate reflection fraction with respect to predictions for the lamp post geometry, in which the illuminating corona is modeled as a point source. Through a time-resolved spectral analysis, we find that modest coron...

  19. In situ apparatus for the study of clathrate hydrates relevant to solar system bodies using synchrotron X-ray diffraction and Raman spectroscopy

    E-Print Network [OSTI]

    Day, Sarah J; Evans, Aneurin; Parker, Julia E

    2015-01-01T23:59:59.000Z

    Clathrate hydrates are believed to play a significant role in various solar system environments, e.g. comets, and the surfaces and interiors of icy satellites, however the structural factors governing their formation and dissociation are poorly understood. We demonstrate the use of a high pressure gas cell, combined with variable temperature cooling and time-resolved data collection, to the in situ study of clathrate hydrates under conditions relevant to solar system environments. Clathrates formed and processed within the cell are monitored in situ using synchrotron X-ray powder diffraction and Raman spectroscopy. X-ray diffraction allows the formation of clathrate hydrates to be observed as CO2 gas is applied to ice formed within the cell. Complete conversion is obtained by annealing at temperatures just below the ice melting point. A subsequent rise in the quantity of clathrate is observed as the cell is thermally cycled. Four regions between 100-5000cm-1 are present in the Raman spectra that carry feature...

  20. Upgraded high time-resolved x-ray imaging crystal spectroscopy system for J-TEXT ohmic plasmas

    SciTech Connect (OSTI)

    Jin, W.; Chen, Z. Y., E-mail: zychen@hust.edu.cn; Huang, D. W.; Li, Q. L.; Yan, W.; Luo, Y. H.; Huang, Y. H.; Tong, R. H.; Yang, Z. J.; Rao, B.; Ding, Y. H.; Zhuang, G. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)] [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Lee, S. G.; Shi, Y. J. [National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of)] [National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of)

    2014-02-15T23:59:59.000Z

    This paper presents the upgraded x-ray imaging crystal spectrometer (XICS) system on Joint Texas Experimental Tokamak (J-TEXT) tokamak and the latest experimental results obtained in last campaign. With 500 Hz frame rate of the new Pilatus detector and 5 cm × 10 cm spherically bent crystal, the XICS system can provide core electron temperature (T{sub e}), core ion temperature (T{sub i}), and plasma toroidal rotation (V{sub ?}) with a maximum temporal resolution of 2 ms for J-TEXT pure ohmic plasmas. These parameters with high temporal resolution are very useful in tokamak plasma research, especially for rapidly changed physical processes. The experimental results from the upgraded XICS system are presented.

  1. Electron mean free path from angle-dependent photoelectron spectroscopy of aerosol particles

    E-Print Network [OSTI]

    Goldmann, Maximilian; West, Adam H C; Yoder, Bruce L; Signorell, Ruth

    2015-01-01T23:59:59.000Z

    We propose angle-resolved photoelectron spectroscopy of aerosol particles as an alternative way to determine the electron mean free path of low energy electrons in solid and liquid materials. The mean free path is obtained from fits of simulated photoemission images to experimental ones over a broad range of different aerosol particle sizes. The principal advantage of the aerosol approach is twofold. Firstly, aerosol photoemission studies can be performed for many different materials, including liquids. Secondly, the size-dependent anisotropy of the photoelectrons can be exploited in addition to size-dependent changes in their kinetic energy. These finite size effects depend in different ways on the mean free path and thus provide more information on the mean free path than corresponding liquid jet, thin film, or bulk data. The present contribution is a proof of principle employing a simple model for the photoemission of electrons and preliminary experimental data for potassium chloride aerosol particles.

  2. A flexible apparatus for attosecond photoelectron spectroscopy of solids and surfaces

    SciTech Connect (OSTI)

    Magerl, E.; Stanislawski, M.; Uphues, Th. [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching (Germany); Neppl, S.; Barth, J. V.; Menzel, D.; Feulner, P. [Physik Department E20, Technische Universitaet Muenchen, James-Franck-Strasse, 85748 Garching (Germany); Cavalieri, A. L. [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching (Germany); Max-Planck Research Department for Structural Dynamics, Universitaet Hamburg, Notkestrasse 85, 22607 Hamburg (Germany); Bothschafter, E. M.; Ernstorfer, R.; Kienberger, R. [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching (Germany); Physik Department E11, Technische Universitaet Muenchen, James-Franck-Strasse, 85748 Garching (Germany); Hofstetter, M.; Kleineberg, U.; Krausz, F. [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching (Germany); Ludwig-Maximilians-Universitaet Muenchen, Fakultaet fuer Physik, Am Coulombwall 1, 85748 Garching (Germany)

    2011-06-15T23:59:59.000Z

    We describe an apparatus for attosecond photoelectron spectroscopy of solids and surfaces, which combines the generation of isolated attosecond extreme-ultraviolet (XUV) laser pulses by high harmonic generation in gases with time-resolved photoelectron detection and surface science techniques in an ultrahigh vacuum environment. This versatile setup provides isolated attosecond pulses with photon energies of up to 140 eV and few-cycle near infrared pulses for studying ultrafast electron dynamics in a large variety of surfaces and interfaces. The samples can be prepared and characterized on an atomic scale in a dedicated flexible surface science end station. The extensive possibilities offered by this apparatus are demonstrated by applying attosecond XUV pulses with a central photon energy of {approx}125 eV in an attosecond streaking experiment of a xenon multilayer grown on a Re(0001) substrate.

  3. X-ray induced optical reflectivity

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Durbin, Stephen M.

    2012-01-01T23:59:59.000Z

    The change in optical reflectivity induced by intense x-ray pulses can now be used to study ultrafast many body responses in solids in the femtosecond time domain. X-ray absorption creates photoelectrons and core level holes subsequently filled by Auger or fluorescence processes, and these excitations ultimately add conduction and valence band carriers that perturb optical reflectivity.Optical absorption associated with band filling and band gap narrowing is shown to explain the basic features found in recent measurements on an insulator (silicon nitride, Si3N4), a semiconductor(gallium arsenide,GaAs), and a metal (gold,Au), obtained with ?100 fs x-ray pulses at 500-2000 eV and probed with 800 nm laser pulses. In particular GaAs exhibits an abrupt drop in reflectivity, persisting only for a time comparable to the x-ray excitation pulse duration, consistent with prompt band gap narrowing.

  4. Setup for in situ investigation of gases and gas/solid interfaces by soft x-ray emission and absorption spectroscopy

    SciTech Connect (OSTI)

    Benkert, A., E-mail: andreas.benkert@kit.edu, E-mail: l.weinhardt@kit.edu [Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology (KIT), Hermann-v.-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Universität Würzburg, Experimentelle Physik VII, Am Hubland, 97074 Würzburg (Germany); Gemeinschaftslabor für Nanoanalytik, Karlsruhe Institute of Technology (KIT), 76021 Karlsruhe (Germany); Blum, M. [Department of Chemistry, University of Nevada, Las Vegas (UNLV), 4505 Maryland Parkway, Nevada 89154-4003 (United States) [Department of Chemistry, University of Nevada, Las Vegas (UNLV), 4505 Maryland Parkway, Nevada 89154-4003 (United States); Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Meyer, F. [Universität Würzburg, Experimentelle Physik VII, Am Hubland, 97074 Würzburg (Germany)] [Universität Würzburg, Experimentelle Physik VII, Am Hubland, 97074 Würzburg (Germany); Wilks, R. G. [Solar Energy Research, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany)] [Solar Energy Research, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Yang, W. [Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)] [Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Bär, M. [Department of Chemistry, University of Nevada, Las Vegas (UNLV), 4505 Maryland Parkway, Nevada 89154-4003 (United States) [Department of Chemistry, University of Nevada, Las Vegas (UNLV), 4505 Maryland Parkway, Nevada 89154-4003 (United States); Solar Energy Research, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Insitut für Physik und Chemie, Brandenburgische Technische Universität Cottbus-Senftenberg, Konrad-Wachsmann-Allee 1, 03046 Cottbus (Germany); and others

    2014-01-15T23:59:59.000Z

    We present a novel gas cell designed to study the electronic structure of gases and gas/solid interfaces using soft x-ray emission and absorption spectroscopies. In this cell, the sample gas is separated from the vacuum of the analysis chamber by a thin window membrane, allowing in situ measurements under atmospheric pressure. The temperature of the gas can be regulated from room temperature up to approximately 600?°C. To avoid beam damage, a constant mass flow can be maintained to continuously refresh the gaseous sample. Furthermore, the gas cell provides space for solid-state samples, allowing to study the gas/solid interface for surface catalytic reactions at elevated temperatures. To demonstrate the capabilities of the cell, we have investigated a TiO{sub 2} sample behind a mixture of N{sub 2} and He gas at atmospheric pressure.

  5. Cation distribution in Ni{sub 1?x}Zn{sub x}Fe{sub 2}O{sub 4} using X-ray absorption spectroscopy

    SciTech Connect (OSTI)

    Yadav, A. K., E-mail: akyadav@barc.gov.in; Jha, S. N.; Bhattacharyya, D.; Sahoo, N. K. [Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai - 400094 (India); Jadhav, J.; Biswas, S. [Department of Physics, The LNM Institute of Information Technology, Jaipur-302031 (India)

    2014-04-24T23:59:59.000Z

    Spinel ferrite samples of Ni{sub 1?x}Zn{sub x}Fe{sub 2}O{sub 4} (for x=0.2, 0.4, 0.5, 0.6 and 0.8) nanoparticles prepared by a novel chemical synthesis method have been characterized by X-ray Absorption Spectroscopy (XAS) technique to investigate the distribution of cations in the unit cell. XANES region clearly shows that as Ni concentration increases, the pre-edge feature, which is a characteristic of tetrahedral coordination of Fe, is enhanced. A quantitative determination of the relative occupancy of iron cation in the octahedral and tetrahedral sites of the spinel structure was obtained from EXAFS data analysis. It has been found that as atomic fraction of Ni is increased from 0.2 to 0.8, Fe occupancy at tetrahedral to octahedral sites is increased from 13:87 and to 39:61.

  6. Time-resolved soft-x-ray spectroscopy of a magnetic octupole transition in nickel-like xenon, cesium, and barium ions

    SciTech Connect (OSTI)

    Trabert, E; Beiersdorfer, P; Brown, G V; Boyce, K; Kelley, R L; Kilbourne, C A; Porter, F S; Szymkowiak, A

    2005-11-11T23:59:59.000Z

    A microcalorimeter with event mode capability for time-resolved soft-x-ray spectroscopy, and a high-resolution flat-field EUV spectrometer have been employed at the Livermore EBIT-I electron beam ion trap for observations and wavelength measurements of M1, E2, and M3 decays of long-lived levels in the Ni-like ions Xe{sup 26+}, Cs{sup 27+}, and Ba{sup 28+}. Of particular interest is the lowest excited level, 3d{sup 9}4s {sup 3}D{sub 3}, which can only decay via a magnetic octupole (M3) transition. For this level in Xe an excitation energy of (590.40 {+-} 0.03eV) and a level lifetime of (11.5 {+-} 0.5 ms) have been determined.

  7. Photo-Induced Spin-State Conversion in Solvated Transition Metal Complexes Probed via Time-Resolved Soft X-ray Spectroscopy

    SciTech Connect (OSTI)

    Huse, Nils; Kim, Tae Kyu; Jamula, Lindsey; McCusker, James K.; de Groot, Frank M. F.; Schoenlein, Robert W.

    2010-04-30T23:59:59.000Z

    Solution-phase photoinduced low-spin to high-spin conversion in the FeII polypyridyl complex [Fe(tren(py)3)]2+ (where tren(py)3 is tris(2-pyridylmethyliminoethyl)amine) has been studied via picosecond soft X-ray spectroscopy. Following 1A1 --> 1MLCT (metal-to-ligand charge transfer) excitation at 560 nm, changes in the iron L2- and L3-edges were observed concomitant with formation of the transient high-spin 5T2 state. Charge-transfer multiplet calculations coupled with data acquired on low-spin and high-spin model complexes revealed a reduction in ligand field splitting of 1 eV in the high-spin state relative to the singlet ground state. A significant reduction in orbital overlap between the central Fe-3d and the ligand N-2p orbitals was directly observed, consistent with the expected ca. 0.2 Angstrom increase in Fe-N bond length upon formation of the high-spin state. The overall occupancy of the Fe-3d orbitals remains constant upon spin crossover, suggesting that the reduction in sigma-donation is compensated by significant attenuation of pi-back-bonding in the metal-ligand interactions. These results demonstrate the feasibility and unique potential of time-resolved soft X-ray absorption spectroscopy to study ultrafast reactions in the liquid phase by directly probing the valence orbitals of first-row metals as well as lighter elements during the course of photochemical transformations.

  8. On Estimating the High-Energy Cutoff in the X-ray Spectra of Black Holes via Reflection Spectroscopy

    E-Print Network [OSTI]

    Garcia, Javier A; Steiner, James F; McClintock, Jeffrey E; Keck, Mason L; Wilms, Joern

    2015-01-01T23:59:59.000Z

    The fundamental parameters describing the coronal spectrum of an accreting black hole are the slope $\\Gamma$ of the power-law continuum and the energy $E_{cut}$ at which it rolls over. Remarkably, this parameter can be accurately measured for values as high as 1 MeV by modeling the spectrum of X-rays reflected from a black hole accretion disk at energies below 100 keV. This is possible because the details in the reflection spectrum, rich in fluorescent lines and other atomic features, are very sensitive to the spectral shape of the hardest coronal radiation illuminating the disk. We show that fitting simultaneous NuSTAR (3-79 keV) and low-energy (e.g., Suzaku) data with the most recent version of our reflection model RELXILL, one can obtain reasonable constraints on $E_{cut}$ at energies from tens of keV up to 1 MeV, for a source as faint as 1 mCrab in a 100 ks observation.

  9. X-ray fluorescence spectroscopy for the elemental analysis of plutonium-bearing materials for the materials disposition program

    SciTech Connect (OSTI)

    Voit, S.L.; Boerigter, S.T.; Rising, T.L.

    1997-11-01T23:59:59.000Z

    The US Fissile Materials Disposition (MD) program will disposition about 50 MT of plutonium in the next century. Both of the alternative technologies for disposition, MOX Fuel and Immobilization require knowledge of the incoming composition to 1--5 wt%. Wavelength Dispersive X-Ray Fluorescence (WDXRF) systems, a common elemental analysis technology with a variety of industrial applications and commercial vendors, can readily achieve this level of characterization. Since much of the excess plutonium will be packaged in a long-term storage container as part of the DOE Environmental Management (DOE-EM) program to stabilize plutonium-bearing materials, the characterization system must be implemented during the packaging process. The authors describe a preliminary design for the integration of the WDXRF system into the packaging system to be used at the Rocky Flats site. The Plutonium Stabilization and Packaging System (PuSPS), coupled with the WDXRF characterization system will provide MD with stabilized plutonium-bearing excess material that can be more readily fed to an immobilization facility. The overall added expense to the MD program of obtaining analytical information after materials have been packaged in long-term storage containers could far exceed the expense of implementing XRF analysis during the packaging process.

  10. Quantification of rapid environmental redox processes with quick-scanning x-ray absorption

    E-Print Network [OSTI]

    Sparks, Donald L.

    Quantification of rapid environmental redox processes with quick-scanning x-ray absorption. Here we apply quick-scanning x-ray absorption spectroscopy (Q-XAS), at sub-second time that can be measured using x-ray absorption spectroscopy. arsenic extended x-ray absorption fine structure

  11. Composition and strain in thin Si{sub 1-x}Ge{sub x} virtual substrates measured by micro-Raman spectroscopy and x-ray diffraction

    SciTech Connect (OSTI)

    Perova, T. S.; Wasyluk, J.; Waldron, A. [Department of Electronic and Electrical Engineering, Trinity College, University of Dublin, Dublin 2 (Ireland); Lyutovich, K.; Kasper, E.; Oehme, M. [Institut fuer Halbleitertechnik, Universitaet Stuttgart, Pfaffenwaldring 47, 70569 Stuttgart (Germany); Rode, K. [School of Physics, CRANN, Trinity College, University of Dublin, Dublin 2 (Ireland)

    2011-02-01T23:59:59.000Z

    Micro-Raman spectroscopy was employed for the determination of the germanium content, x and strain, {epsilon}, in ultrathin SiGe virtual substrates grown directly on Si by molecular beam epitaxy. The growth of highly relaxed SiGe layers was achieved by the introduction of point defects at a very low temperature during the initial stage of growth. SiGe virtual substrates with thicknesses in the range 40-200 nm with a high Ge content (up to 50%) and degree of relaxation, r, in the range 20%-100% were investigated using micro-Raman spectroscopy and x-ray diffraction (XRD) techniques. The Ge content, x, and strain, {epsilon}, were estimated from equations describing Si-Si, Si-Ge, and Ge-Ge Raman vibrational modes, modified in this study for application to thin SiGe layers. The alteration of the experimentally derived equations from previous studies was performed using independent data for x and r obtained from XRD reciprocal space maps. A number of samples consisting of a strained-silicon (s-Si) layer deposited on a SiGe virtual substrate were also analyzed. The stress value for the s-Si varied from 0.54 to 2.75 GPa, depending on the Ge-content in the virtual substrates. These results are in good agreement with theoretically predicted values.

  12. Chest x-Rays

    Broader source: Energy.gov [DOE]

    The B-reading is a special reading of a standard chest x-ray film performed by a physician certified by the National Institute for Occupational Safety and Health (NIOSH). The reading looks for changes on the chest x-ray that may indicate exposure and disease caused by agents such as asbestos or silica.

  13. Photoelectronic characterization of heterointerfaces.

    SciTech Connect (OSTI)

    Brumbach, Michael Todd

    2012-02-01T23:59:59.000Z

    In many devices such as solar cells, light emitting diodes, transistors, etc., the performance relies on the electronic structure at interfaces between materials within the device. The objective of this work was to perform robust characterization of hybrid (organic/inorganic) interfaces by tailoring the interfacial region for photoelectron spectroscopy. Self-assembled monolayers (SAM) were utilized to induce dipoles of various magnitudes at the interface. Additionally, SAMs of molecules with varying dipolar characteristics were mixed into spatially organized structures to systematically vary the apparent work function. Polymer thin films were characterized by depositing films of varying thicknesses on numerous substrates with and without interfacial modifications. Hard X-ray photoelectron spectroscopy (HAXPES) was performed to evaluate a buried interface between indium tin oxide (ITO), treated under various conditions, and poly(3-hexylthiophene) (P3HT). Conducting polymer films were found to be sufficiently conducting such that no significant charge redistribution in the polymer films was observed. Consequently, a further departure from uniform substrates was taken whereby electrically disconnected regions of the substrate presented ideally insulating interfacial contacts. In order to accomplish this novel strategy, interdigitated electrodes were used as the substrate. Conducting fingers of one half of the electrodes were electrically grounded while the other set of electrodes were electronically floating. This allowed for the evaluation of substrate charging on photoelectron spectra (SCOPES) in the presence of overlying semiconducting thin films. Such an experiment has never before been reported. This concept was developed out of the previous experiments on interfacial modification and thin film depositions and presents new opportunities for understanding chemical and electronic changes in a multitude of materials and interfaces.

  14. A high-order harmonic generation apparatus for time- and angle-resolved photoelectron spectroscopy

    SciTech Connect (OSTI)

    Frietsch, B.; Gahl, C.; Teichmann, M.; Weinelt, M. [Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany)] [Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany); Carley, R. [Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany) [Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany); Max-Born-Institut, Max-Born-Str. 2a, 12489 Berlin (Germany); Döbrich, K. [Max-Born-Institut, Max-Born-Str. 2a, 12489 Berlin (Germany)] [Max-Born-Institut, Max-Born-Str. 2a, 12489 Berlin (Germany); Schwarzkopf, O.; Wernet, Ph. [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489 Berlin (Germany)] [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489 Berlin (Germany)

    2013-07-15T23:59:59.000Z

    We present a table top setup for time- and angle-resolved photoelectron spectroscopy to investigate band structure dynamics of correlated materials driven far from equilibrium by femtosecond laser pulse excitation. With the electron-phonon equilibration time being in the order of 1–2 ps it is necessary to achieve sub-picosecond time resolution. Few techniques provide both the necessary time and energy resolution to map non-equilibrium states of the band structure. Laser-driven high-order harmonic generation is such a technique. In our experiment, a grating monochromator delivers tunable photon energies up to 40 eV. A photon energy bandwidth of 150 meV and a pulse duration of 100 fs FWHM allow us to cover the k-space necessary to map valence bands at different k{sub z} and detect outer core states.

  15. Photodissociation and charge transfer dynamics of negative ions studied with femtosecond photoelectron spectroscopy

    SciTech Connect (OSTI)

    Zanni, Martin T.

    1999-12-17T23:59:59.000Z

    This dissertation presents studies aimed at understanding the potential energy surfaces and dynamics of isolated negative ions, and the effects of solvent on each. Although negative ions play important roles in atmospheric and solution phase chemistry, to a large extent the ground and excited state potential energy surfaces of gas phase negative ions are poorly characterized, and solvent effects even less well understood. In an effort to fill this gap, the author's coworkers and the author have developed a new technique, anion femtosecond photoelectron spectroscopy, and applied it to gas phase photodissociation and charge transfer processes. Studies are presented that (1) characterize the ground and excited states of isolated and clustered anions, (2) monitor the photodissociation dynamics of isolated and clustered anions, and (3) explore the charge-transfer-to-solvent states of atomic iodide clustered with polar and non-polar solvents.

  16. Study of radicals, clusters and transition state species by anion photoelectron spectroscopy

    SciTech Connect (OSTI)

    Arnold, D.W.

    1994-08-01T23:59:59.000Z

    Free radicals, elemental and van der Waals clusters and transition state species for bimolecular chemical reactions are investigated using anion photoelectron spectroscopy. Several low-lying electronic states of ozone have been identified via photoelectron spectroscopy of O{sub 3}{sup {minus}}. A characterization of these states is important to models for atmospheric ozone reaction kinetics. The fluoroformyloxyl radical, FCO{sub 2}, has been investigated, providing vibrational frequencies and energies for two electronic states. The technique has also been employed to make the first direct observation and characterization of the NNO{sub 2} molecule. Several electronic states are observed for this species which is believed to play a role as a reactive intermediate in the N + NO{sub 2} reaction. The experimental results for all three of these radicals are supplemented by ab initio investigations of their molecular properties. The clusters investigations include studies of elemental carbon clusters (C{sub 2}{sup {minus}} {minus} C{sub 11}{sup {minus}}), and van der Waals clusters (X{sup {minus}}(CO{sub 2}){sub n}, X = I, Br, Cl; n {le} 13 and I{sup {minus}} (N{sub 2}O){sub n=1--11}). Primarily linear clusters are observed for the smaller carbon clusters, while the spectra of the larger clusters contain contribution from cyclic anion photodetachment. Very interesting ion-solvent interactions are observed in the X{sup {minus}}(CO{sub 2})n clusters. The transition state regions for several bimolecular chemical reactions have also been investigated by photodetachment of a negative ion precursor possessing a geometry similar to that of the transition state species. These spectra show features which are assigned to motions of the unstable neutral complex existing between reactants and products.

  17. X-ray laser

    DOE Patents [OSTI]

    Nilsen, Joseph (Livermore, CA)

    1991-01-01T23:59:59.000Z

    An X-ray laser (10) that lases between the K edges of carbon and oxygen, i.e. between 44 and 23 Angstroms, is provided. The laser comprises a silicon (12) and dysprosium (14) foil combination (16) that is driven by two beams (18, 20) of intense line focused (22, 24) optical laser radiation. Ground state nickel-like dysprosium ions (34) are resonantly photo-pumped to their upper X-ray laser state by line emission from hydrogen-like silicon ions (32). The novel X-ray laser should prove especially useful for the microscopy of biological specimens.

  18. Experimental Verification of the Chemical Sensitivity of Two-Site Double Core-Hole States Formed by an X-ray FEL

    E-Print Network [OSTI]

    Salen, P; Schmidt, H T; Thomas, R D; Larsson, M; Feifel, R; Piancastelli, M N; Fang, L; Murphy, B; Osipov, T; Berrah, N; Kukk, E; Ueda, K; Bozek, J D; Bostedt, C; Wada, S; Richter, R; Feyer, V; Prince, K C

    2012-01-01T23:59:59.000Z

    We have performed X-ray two-photon photoelectron spectroscopy (XTPPS) using the Linac Coherent Light Source (LCLS) X-ray free-electron laser (FEL) in order to study double core-hole (DCH) states of CO2, N2O and N2. The experiment verifies the theory behind the chemical sensitivity of two-site (ts) DCH states by comparing a set of small molecules with respect to the energy shift of the tsDCH state and by extracting the relevant parameters from this shift.

  19. High resolution soft x-ray spectroscopy of low Z K-shell emission from laser-produced plasmas

    SciTech Connect (OSTI)

    Dunn, J; Magee, E W; Shepherd, R; Chen, H; Hansen, S B; Moon, S J; Brown, G V; Gu, M; Beiersdorfer, P; Purvis, M A

    2008-05-21T23:59:59.000Z

    A large radius, R = 44.3 m, High Resolution Grating Spectrometer (HRGS) with 2400 line/mm variable line spacing has been designed for laser-produced plasma experiments conducted at the Lawrence Livermore National Laboratory Jupiter Laser Facility. The instrument has been run with a low-noise, charge-coupled device detector to record high signal-to-noise spectra in the 10-50 {angstrom} wavelength range. The instrument can be run with a 10-20 {micro}m wide slit to achieve the best spectral resolving power, approaching 1000 and similar to crystal spectrometers at 12-20 {angstrom}, or in slitless operation with a small symmetrical emission source. We describe preliminary spectra emitted from various H-like and He-like low Z ion plasmas heated by 100-500 ps (FWHM), 527 nm wavelength laser pulses. This instrument can be developed as a useful spectroscopy platform relevant to laboratory-based astrophysics as well as high energy density plasma studies.

  20. Performance and characteristics of a high pressure, high temperature capillary cell with facile construction for operando x-ray absorption spectroscopy

    SciTech Connect (OSTI)

    Bansode, Atul; Urakawa, Atsushi, E-mail: aurakawa@iciq.es [Institute of Chemical Research of Catalonia (ICIQ), Av. Països Catalans 16, 43007 Tarragona (Spain); Guilera, Gemma; Simonelli, Laura; Avila, Marta [ALBA Synchrotron Light Source, Crta. BP 1413, Km. 3.3, 08290 Cerdanyola del Vallès, Barcelona (Spain); Cuartero, Vera [ALBA Synchrotron Light Source, Crta. BP 1413, Km. 3.3, 08290 Cerdanyola del Vallès, Barcelona (Spain); European Synchrotron Radiation Facility (ESRF), CS40220, F-38043, Grenoble Cedex (France)

    2014-08-15T23:59:59.000Z

    We demonstrate the use of commercially available fused silica capillary and fittings to construct a cell for operando X-ray absorption spectroscopy (XAS) for the study of heterogeneously catalyzed reactions under high pressure (up to 200 bars) and high temperature (up to 280?°C) conditions. As the first demonstration, the cell was used for CO{sub 2} hydrogenation reaction to examine the state of copper in a conventional Cu/ZnO/Al{sub 2}O{sub 3} methanol synthesis catalyst. The active copper component of the catalyst was shown to remain in the metallic state under supercritical reaction conditions, at 200 bars and up to 260?°C. With the coiled heating system around the capillary, one can easily change the length of the capillary and control the amount of catalyst under investigation. With precise control of reactant(s) flow, the cell can mimic and serve as a conventional fixed-bed micro-reactor system to obtain reliable catalytic data. This high comparability of the reaction performance of the cell and laboratory reactors is crucial to gain insights into the nature of actual active sites under technologically relevant reaction conditions. The large length of the capillary can cause its bending upon heating when it is only fixed at both ends because of the thermal expansion. The degree of the bending can vary depending on the heating mode, and solutions to this problem are also presented. Furthermore, the cell is suitable for Raman studies, nowadays available at several beamlines for combined measurements. A concise study of CO{sub 2} phase behavior by Raman spectroscopy is presented to demonstrate a potential of the cell for combined XAS-Raman studies.

  1. Tools for a Theoretical X-ray Beamline J. J. Rehr*

    E-Print Network [OSTI]

    Botti, Silvana

    Tools for a Theoretical X-ray Beamline J. J. Rehr* Department of Physics University of Washington, France 22 October 2010 #12;X-ray Spectroscopy Beamline #12;Tools for a Theoretical X-ray Beamline · GOAL Theoretical X-ray Beamline: 2. Tools for EXAFS and XANES, EELS, XMCD, ... 3. DFT/MD-TOOLS 4. Next generation

  2. Photoelectron Spectroscopy and Theoretical Studies of UF5 ? and UF6 ?

    SciTech Connect (OSTI)

    Dau, Phuong D.; Su, Jing; Liu, Hong-Tao; Huang, Dao-Ling; Wei, Fan; Li, Jun; Wang, Lai S.

    2012-05-17T23:59:59.000Z

    The UF5 ? and UF6 ? anions are produced using electrospray ionization and investigated by photoelectron spectroscopy and relativistic quantum chemistry. An extensive vibrational progression is observed in the spectra of UF5 ?, indicating significant geometry changes between the anion and neutral ground state. Franck-Condon factor simulations of the observed vibrational progression yield an adiabatic electron detachment energy of 3.82 ± 0.05 eV for UF5 ?. Relativistic quantum calculations using density functional and ab initio theories are performed on UF5 ? and UF6 ? and their neutrals. The ground states of UF5 ? and UF5 are found to have C4v symmetry, but with a large U?F bond length change. The ground state of UF5 ? is a triplet state (3B2) with the two 5f electrons occupying a 5fz3-based 8a1 highest occupied molecular orbital (HOMO) and the 5fxyz-based 2b2 HOMO-1 orbital. The detachment cross section from the 5fxyz orbital is observed to be extremely small and the detachment transition from the 2b2 orbital is more than ten times weaker than that from the 8a1 orbital at the photon energies available. The UF6 ? anion is found to be octahedral, similar to neutral UF6 with the extra electron occupying the 5fxyz-based a2u orbital. Surprisingly, no photoelectron spectrum could be observed for UF6 ? due to the extremely low detachment cross section from the 5fxyz-based HOMO of UF6 ?.

  3. Improving metastable impact electron spectroscopy and ultraviolet photoelectron spectroscopy signals by means of a modified time-of-flight separation

    SciTech Connect (OSTI)

    Spirkl, Florian M.; Kunz, Sebastian; Schweinberger, Florian F.; Farnbacher, Adrian N.; Schroeter, Richard; Heiz, Ulrich [Technische Universitaet Muenchen, Department Chemie, Lichtenbergstrasse 4, D-85748 Garching (Germany)

    2012-01-15T23:59:59.000Z

    The separation of ultraviolet photoelectron spectroscopy (UPS) and metastable impact electron spectroscopy (MIES) is usually performed by a time-of-flight (ToF) separation using pre-set ToF for both types of signal. In this work, we present a new, improved ex situ signal separation method for the separation of MIES and UPS for every single measurement. Signal separation issues due to changes of system parameters can be overcome by changing the ToF separation and therefore allowing for the application of a wider range of measuring conditions. The method also enables to identify and achieve separation of the two signals without any time consuming calibration and the use of any special material for the calibration. Furthermore, changes made to the discharge source are described that enable to operate an existing MIES/UPS source over a broader range of conditions. This allows for tuning of the yield of UV photons and metastable rare gas atoms leading to an improved signal to noise ratio. First results of this improved setup are well in agreement with spectra reported in literature and show increased resolution and higher signal intensities for both MIE and UP spectra compared to the previous, non-optimized setup.

  4. X-ray beam finder

    DOE Patents [OSTI]

    Gilbert, H.W.

    1983-06-16T23:59:59.000Z

    An X-ray beam finder for locating a focal spot of an X-ray tube includes a mass of X-ray opaque material having first and second axially-aligned, parallel-opposed faces connected by a plurality of substantially identical parallel holes perpendicular to the faces and a film holder for holding X-ray sensitive film tightly against one face while the other face is placed in contact with the window of an X-ray head.

  5. X-Ray Diagnostics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengtheningWildfires may contribute more toConsensusX-Ray Diagnostics X-Ray

  6. Magnetron Plasma Sputtered Nanocomposite Thin Films: Structural Surface Studies by In Vacuo Photoelectron Spectroscopy

    SciTech Connect (OSTI)

    Videnovic, Ivan R. [Faculty of Physics, University of Belgrade, P.O. Box 368, 11000 Belgrade (Serbia and Montenegro); Institut fuer Physik, Universitaet Basel, Klingelbergstr. 82, CH-4056 Basel (Switzerland)

    2004-12-01T23:59:59.000Z

    The experimental system that enables thin film deposition by chemical vapor deposition combined with magnetron sputtering and sample surface characterization by photoelectron spectroscopy (PES), without breaking the vacuum between the deposition and the characterization stage, is described. The particular goal of this work was study of the surface arrangement of embedded metallic nanoclusters of 1B group (Au, Ag, and Cu) in amorphous hydrogenated carbon (a-C:H). From the range of applied material characterization tools, we present here the results of several PES-based experiments used to reveal cluster properties at the surface: as-deposited sample PES measurements, off-normal take-off angle XPS, and in situ in-depth XPS profiling by Ar+ ion etching. Clear distinction in all PES results of the samples deposited on the grounded substrates from those deposited on -150 V dc biased ones is obtained, revealing that keeping the substrate grounded during deposition results in topmost metallic clusters covered with a very thin layer of a-C:H, while applying negative bias voltage to the substrate results in partially bald clusters on the surface.

  7. Silicon drift detector based X-ray spectroscopy diagnostic system for the study of non-thermal electrons at Aditya tokamak

    SciTech Connect (OSTI)

    Purohit, S., E-mail: pshishir@ipr.res.in; Joisa, Y. S.; Raval, J. V.; Ghosh, J.; Tanna, R.; Shukla, B. K.; Bhatt, S. B. [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India)

    2014-11-15T23:59:59.000Z

    Silicon drift detector based X-ray spectrometer diagnostic was developed to study the non-thermal electron for Aditya tokamak plasma. The diagnostic was mounted on a radial mid plane port at the Aditya. The objective of diagnostic includes the estimation of the non-thermal electron temperature for the ohmically heated plasma. Bi-Maxwellian plasma model was adopted for the temperature estimation. Along with that the study of high Z impurity line radiation from the ECR pre-ionization experiments was also aimed. The performance and first experimental results from the new X-ray spectrometer system are presented.

  8. CHANDRA X-RAY SPECTROSCOPY OF THE FOCUSED WIND IN THE CYGNUS X-1 SYSTEM. I. THE NONDIP SPECTRUM IN THE LOW/HARD STATE

    E-Print Network [OSTI]

    Hanke, Manfred

    We present analyses of a 50 ks observation of the supergiant X-ray binary system Cygnus X-1 (Cyg X-1)/HDE226868 taken with the Chandra High Energy Transmission Grating Spectrometer (HETGS). Cyg X-1 was in its spectrally ...

  9. Fluctuation X-Ray Scattering

    SciTech Connect (OSTI)

    Saldin, PI: D. K.; Co-I's: J. C. H. Spence and P. Fromme

    2013-01-25T23:59:59.000Z

    The work supported by the grant was aimed at developing novel methods of finding the structures of biomolecules using x-rays from novel sources such as the x-ray free electron laser and modern synchrotrons

  10. Tunable X-ray source

    DOE Patents [OSTI]

    Boyce, James R. (Williamsburg, VA)

    2011-02-08T23:59:59.000Z

    A method for the production of X-ray bunches tunable in both time and energy level by generating multiple photon, X-ray, beams through the use of Thomson scattering. The method of the present invention simultaneously produces two X-ray pulses that are tunable in energy and/or time.

  11. X-ray photoelectron spectroscopy of negative electrodes from high-power lithium-ion cells showing various levels of power fade

    E-Print Network [OSTI]

    Herstedt, Marie; Abraham, Daniel P.; Kerr, John B.

    2004-01-01T23:59:59.000Z

    Electrodes from High-Power Lithium-Ion Cells Showing VariousAbstract High-power lithium-ion cells for transportationknown electrolytes during lithium ion intercalation this SEI

  12. Water adsorption, solvation and deliquescence of alkali halide thin films on SiO2 studied by ambient pressure X-ray photoelectron spectroscopy

    E-Print Network [OSTI]

    Arima, Kenta

    2011-01-01T23:59:59.000Z

    Water adsorption, solvation and deliquescence of alkali94720, USA Abstract The adsorption of water on KBr thinBr and Cl, but not for F upon adsorption of water and after

  13. Broadband high resolution X-ray spectral analyzer

    DOE Patents [OSTI]

    Silver, E.H.; Legros, M.; Madden, N.W.; Goulding, F.; Landis, D.

    1998-07-07T23:59:59.000Z

    A broad bandwidth high resolution X-ray fluorescence spectrometer has a performance that is superior in many ways to those currently available. It consists of an array of 4 large area microcalorimeters with 95% quantum efficiency at 6 keV and it produces X-ray spectra between 0.2 keV and 7 keV with an energy resolution of 7 to 10 eV. The resolution is obtained at input count rates per array element of 10 to 50 Hz in real-time, with analog pulse processing and thermal pile-up rejection. This performance cannot be matched by currently available X-ray spectrometers. The detectors are incorporated into a compact and portable cryogenic refrigerator system that is ready for use in many analytical spectroscopy applications as a tool for X-ray microanalysis or in research applications such as laboratory and astrophysical X-ray and particle spectroscopy. 6 figs.

  14. Broadband high resolution X-ray spectral analyzer

    DOE Patents [OSTI]

    Silver, Eric H. (Berkeley, CA); Legros, Mark (Berkeley, CA); Madden, Norm W. (Livermore, CA); Goulding, Fred (Lafayette, CA); Landis, Don (Pinole, CA)

    1998-01-01T23:59:59.000Z

    A broad bandwidth high resolution x-ray fluorescence spectrometer has a performance that is superior in many ways to those currently available. It consists of an array of 4 large area microcalorimeters with 95% quantum efficiency at 6 keV and it produces x-ray spectra between 0.2 keV and 7 keV with an energy resolution of 7 to 10 eV. The resolution is obtained at input count rates per array element of 10 to 50 Hz in real-time, with analog pulse processing and thermal pile-up rejection. This performance cannot be matched by currently available x-ray spectrometers. The detectors are incorporated into a compact and portable cryogenic refrigerator system that is ready for use in many analytical spectroscopy applications as a tool for x-ray microanalysis or in research applications such as laboratory and astrophysical x-ray and particle spectroscopy.

  15. Valence band density of states of zinc-blende and wurtzite InN from x-ray photoemission spectroscopy and first-principles calculations

    E-Print Network [OSTI]

    As, Donat Josef

    Valence band density of states of zinc-blende and wurtzite InN from x-ray photoemission for wurtzite InN 112¯0 are shown to yield a VB-DOS similar to that of zinc-blende InN, although the nonzero the thermodynamically stable phase is the wurtzite 2H polymorph4 wz-InN , judicious choice of substrate material

  16. Quick extended x-ray absorption fine structure instrument with millisecond time scale, optimized for in situ applications

    E-Print Network [OSTI]

    Sparks, Donald L.

    Quick extended x-ray absorption fine structure instrument with millisecond time scale, optimized of quick extended x-ray absorption fine structure QEXAFS and quick x-ray absorption near edge structure- tion spectroscopy XAS was developed in energy dispersive and quick extended x-ray absorption fine

  17. Summary of ISO/TC 201 Standard: ISO 29081: 2010, Surface Chemical Analysis - Auger Electron Spectroscopy - Reporting of Methods Used for Charge Control and Charge Correction

    SciTech Connect (OSTI)

    Baer, Donald R.

    2011-11-01T23:59:59.000Z

    This international standard specifies the minimum amount of information required for describing the methods of charge control in measurements of Auger electron transitions from insulating specimens by electron-stimulated Auger electron spectroscopy to be reported with the analytical results. Information is provided in an Annex on methods that have been found useful for charge control prior to or during AES analysis. The Annex also includes a summary table of methods or approaches, ordered by simplicity of approach. A similar international standard has been published for x-ray photoelectron spectroscopy (ISO 19318: 2003(E), Surface chemical analysis - X-ray photoelectron spectroscopy - Reporting of methods used for charge control and charge correction).

  18. A new spectrometer design for the x-ray spectroscopy of laser-produced plasmas with high (sub-ns) time resolution

    SciTech Connect (OSTI)

    Bitter, M., E-mail: bitter@pppl.gov; Hill, K. W.; Efthimion, P. C.; Delgado-Aparicio, L.; Pablant, N. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Lu, Jian [Department of Engineering, Chongqing University, Chongqing 400044 (China); Beiersdorfer, P.; Chen, Hui [Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2014-11-15T23:59:59.000Z

    This paper describes a new type of x-ray crystal spectrometer, which can be used in combination with gated x-ray detectors to obtain spectra from laser-produced plasmas with a high (sub-ns) time resolution. The spectrometer consists of a convex, spherically bent crystal, which images individual spectral lines as perfectly straight lines across multiple, sequentially gated, strip detectors. Since the Bragg-reflected rays are divergent, the distance between detector and crystal is arbitrary, so that this distance can be appropriately chosen to optimize the experimental arrangement with respect to the detector parameters. The spectrometer concept was verified in proof-of-principle experiments by imaging the L?{sub 1}- and L?{sub 2}-lines of tungsten, at 9.6735 and 9.96150 keV, from a micro-focus x-ray tube with a tungsten target onto a two-dimensional pixilated Pilatus detector, using a convex, spherically bent Si-422 crystal with a radius of curvature of 500 mm.

  19. X-ray lithography source

    DOE Patents [OSTI]

    Piestrup, Melvin A. (Woodside, CA); Boyers, David G. (Mountain View, CA); Pincus, Cary (Sunnyvale, CA)

    1991-01-01T23:59:59.000Z

    A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and elminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an exellent moderate-priced X-ray source for lithography.

  20. X-ray lithography source

    DOE Patents [OSTI]

    Piestrup, M.A.; Boyers, D.G.; Pincus, C.

    1991-12-31T23:59:59.000Z

    A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits is disclosed. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and eliminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an excellent moderate-priced X-ray source for lithography. 26 figures.

  1. Femtosecond photoelectron spectroscopy: a new tool for the study of anion dynamics

    SciTech Connect (OSTI)

    Greenblatt, B.J.

    1999-02-01T23:59:59.000Z

    A new experimental technique for the time-resolved study of anion reactions is presented. Using femtosecond laser pulses, which provide extremely fast ({approx} 100 fs) time resolution, in conjunction with photoelectron spectroscopy, which reveals differences between anion and neutral potential energy surfaces, a complex anion reaction can be followed from its inception through the formation of asymptotic products. Experimental data can be modeled quantitatively using established theoretical approaches, allowing for the refinement of potential energy surfaces as well as dynamical models. After a brief overview, a detailed account of the construction of the experimental apparatus is presented. Documentation of the data acquisition program is contained in the Appendix. The first experimental demonstration of the technique is then presented for I{sub 2}{sup -} photodissociation, modeled using a simulation program which is also detailed in the Appendix. The investigation of I{sub 2}{sup -} photodissociation in several size-selected I{sub 2}{sup -}(Ar){sub n} (n = 6-20) and I{sub 2}{sup -}(CO{sub 2}){sub n} (n = 4-16) clusters forms the heart of the dissertation. In a series of chapters, the numerous effects of solvation on this fundamental bond-breaking reaction are explored, the most notable of which is the recombination of I{sub 2}{sup -} on the ground {tilde X}({sup 2}{Sigma}{sub u}{sup +}) state in sufficiently large clusters. Recombination and trapping of I{sub 2}{sup -} on the excited {tilde A}({sup 2}{Pi}{sub 3/2,g}) state is also observed in both types of clusters. The studies have revealed electronic state transitions, the first step in recombination, on a {approx}500 fs to {approx}10 ps timescale. Accompanying the changes in electronic state is solvent reorganization, which occurs on a similar timescale. Over longer periods ({approx}1 ps to >200 ps), energy is transferred from vibrationally excite d I{sub 2}{sup -} to modes of the solvent, which in turn leads to solvent evaporation. These effects become more important as cluster size increases. In addition, differences in timescale and mechanism are observed between clusters of Ar, which binds to I{sup -} and I{sub 2}{sup -} rather weakly, and CO{sub 2}, whose large quadruple moment allows substantially stronger binding to these anions.

  2. C-C bond unsaturation degree in monosubstituted ferrocenes for molecular electronics investigated by a combined near-edge x-ray absorption fine structure, x-ray photoemission spectroscopy, and density functional theory approach

    SciTech Connect (OSTI)

    Boccia, A.; Lanzilotto, V.; Marrani, A. G.; Zanoni, R. [Dipartimento di Chimica, Universita degli Studi di Roma ''La Sapienza'', piazzale Aldo Moro 5, I-00185 Rome (Italy); Stranges, S. [Dipartimento di Chimica, Universita degli Studi di Roma ''La Sapienza'', piazzale Aldo Moro 5, I-00185 Rome (Italy); IOM-CNR, Laboratorio TASC, I-34149 Basovizza, Trieste (Italy); Alagia, M. [IOM-CNR, Laboratorio TASC, I-34149 Basovizza, Trieste (Italy); Fronzoni, G.; Decleva, P. [Dipartimento di Scienze Chimiche, Universita di Trieste, Via L. Giorgieri 1, I-34127 Trieste, Italy and IOM-CNR Democritos, Trieste (Italy)

    2012-04-07T23:59:59.000Z

    We present the results of an experimental and theoretical investigation of monosubstituted ethyl-, vinyl-, and ethynyl-ferrocene (EtFC, VFC, and EFC) free molecules, obtained by means of synchrotron-radiation based C 1s photoabsorption (NEXAFS) and photoemission (C 1s XPS) spectroscopies, and density functional theory (DFT) calculations. Such a combined study is aimed at elucidating the role played by the C-C bond unsaturation degree of the substituent on the electronic structure of the ferrocene derivatives. Such substituents are required for molecular chemical anchoring onto relevant surfaces when ferrocenes are used for molecular electronics hybrid devices. The high resolution C 1s NEXAFS spectra exhibit distinctive features that depend on the degree of unsaturation of the hydrocarbon substituent. The theoretical approach to consider the NEXAFS spectrum made of three parts allowed to disentangle the specific contribution of the substituent group to the experimental spectrum as a function of its unsaturation degree. C 1s IEs were derived from the experimental data analysis based on the DFT calculated IE values for the different carbon atoms of the substituent and cyclopentadienyl (Cp) rings. Distinctive trends of chemical shifts were observed for the substituent carbon atoms and the substituted atom of the Cp ring along the series of ferrocenes. The calculated IE pattern was rationalized in terms of initial and final state effects influencing the IE value, with special regard to the different mechanism of electron conjugation between the Cp ring and the substituent, namely the {sigma}/{pi} hyperconjugation in EtFC and the {pi}-conjugation in VFC and EFC.

  3. X-ray absorption spectroscopic studies of the active sites of nickel- and copper-containing metalloproteins

    SciTech Connect (OSTI)

    Tan, G.O.

    1993-06-01T23:59:59.000Z

    X-ray absorption spectroscopy (XAS) is a useful tool for obtaining structural and chemical information about the active sites of metalloproteins and metalloenzymes. Information may be obtained from both the edge region and the extended X-ray absorption fine structure (EXAFS) or post-edge region of the K-edge X-ray absorption spectrum of a metal center in a compound. The edge contains information about the valence electronic structure of the atom that absorbs the X-rays. It is possible in some systems to infer the redox state of the metal atom in question, as well as the geometry and nature of ligands connected to it, from the features in the edge in a straightforward manner. The EXAFS modulations, being produced by the backscattering of the ejected photoelectron from the atoms surrounding the metal atom, provide, when analyzed, information about the number and type of neighbouring atoms, and the distances at which they occur. In this thesis, analysis of both the edge and EXAFS regions has been used to gain information about the active sites of various metalloproteins. The metalloproteins studied were plastocyanin (Pc), laccase and nickel carbon monoxide dehydrogenase (Ni CODH). Studies of Cu(I)-imidazole compounds, related to the protein hemocyanin, are also reported here.

  4. Ultrafast extended x-ray absorption fine structure ,,EXAFS...--theoretical considerations

    E-Print Network [OSTI]

    Cao, Jianshu

    13­20 to generate ultrafast x-ray pulses, however, the prospect of ultrafast EXAFS seems encouragingUltrafast extended x-ray absorption fine structure ,,EXAFS...--theoretical considerations Frank L by the recent experimental demonstration of ultrafast x-ray absorption spectroscopy, we present a framework

  5. X-ray spectrometry

    SciTech Connect (OSTI)

    Markowicz, A.A.; Van Grieken, R.E.

    1986-04-01T23:59:59.000Z

    In the period under review, i.e, through 1984 and 1985, some 600 articles on XRS (X-ray spectrometry) were published; most of these have been scanned and the most fundamental ones are discussed. All references will refer to English-language articles, unless states otherwise. Also general books have appeared on quantitative EPXMA (electron-probe X-ray microanalysis) and analytical electron microscopy (AEM) as well as an extensive review on the application of XRS to trace analysis of environmental samples. In the period under review no radically new developments have been seen in XRS. However, significant improvements have been made. Gain in intensities has been achieved by more efficient excitation, higher reflectivity of dispersing media, and better geometry. Better understanding of the physical process of photon- and electron-specimen interactions led to complex but more accurate equations for correction of various interelement effects. Extensive use of micro- and minicomputers now enables fully automatic operation, including qualitative analysis. However, sample preparation and presentation still put a limit to further progress. Although some authors find XRS in the phase of stabilization or even stagnation, further gradual developments are expected, particularly toward more dedicated equipment, advanced automation, and image analysis systems. Ways are outlined in which XRS has been improved in the 2 last years by excitation, detection, instrumental, methodological, and theoretical advances. 340 references.

  6. State-Dependent Electron Delocalization Dynamics at the Solute-Solvent Interface: Soft X-ray Absorption Spectroscopy and Ab Initio Calculations

    E-Print Network [OSTI]

    Bokarev, Sergey I; Suljoti, Edlira; Kühn, Oliver; Aziz, Emad F

    2013-01-01T23:59:59.000Z

    Non-radiative decay channels in the L-edge fluorescence spectra from transition metal-aqueous solutions give rise to spectral dips in X-ray transmission spectra. Their origin is unraveled here using partial and inverse partial fluorescence yields on the micro-jet combined with multi-reference ab initio electronic structure calculations. Comparing Fe2+, Fe3+, and Co2+ systems we demonstrate unequivocally that spectral dips are due to a state-dependent electron delocalization within the manifold of d-orbitals.

  7. Miniature x-ray source

    DOE Patents [OSTI]

    Trebes, James E. (Livermore, CA); Stone, Gary F. (Livermore, CA); Bell, Perry M. (Tracy, CA); Robinson, Ronald B. (Modesto, CA); Chornenky, Victor I. (Minnetonka, MN)

    2002-01-01T23:59:59.000Z

    A miniature x-ray source capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature x-ray source comprises a compact vacuum tube assembly containing a cathode, an anode, a high voltage feedthru for delivering high voltage to the anode, a getter for maintaining high vacuum, a connection for an initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is highly x-ray transparent and made, for example, from boron nitride. The compact size and potential for remote operation allows the x-ray source, for example, to be placed adjacent to a material sample undergoing analysis or in proximity to the region to be treated for medical applications.

  8. A new spectrometer design for the x-ray spectroscopy of laser-produced plasmas with high (sub-ns) time resolutiona)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bitter, M. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA; Hill, K. W. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA; Efthimion, P. C. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA; Delgado-Aparicio, L. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA; Pablant, N. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA; Lu, Jian [Department of Engineering, Chongqing University, Chongqing 400044, China; Beiersdorfer, P. [Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA; Chen, Hui [Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA

    2014-11-01T23:59:59.000Z

    This paper describes a new type of x-ray crystal spectrometer, which can be used in combination with gated x-ray detectors to obtain spectra from laser-produced plasmas with a high (sub-ns) time resolution. The spectrometer consists of a convex, spherically bent crystal, which images individual spectral lines as perfectly straight lines across multiple, sequentially gated, strip detectors. Since the Bragg-reflected rays are divergent, the distance between detector and crystal is arbitrary, so that this distance can be appropriately chosen to optimize the experimental arrangement with respect to the detector parameters. The spectrometer concept was verified in proof-of-principle experiments by imaging the L?1- and L?2-lines of tungsten, at 9.6735 and 9.96150 keV, from a micro-focus xray tube with a tungsten target onto a two-dimensional pixilated Pilatus detector, using a convex, spherically bent Si-422 crystal with a radius of curvature of 500 mm.

  9. A new spectrometer design for the x-ray spectroscopy of laser-produced plasmas with high (sub-ns) time resolutiona)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bitter, M.; Hill, K. W.; Efthimion, P. C.; Delgado-Aparicio, L.; Pablant, N.; Lu, Jian; Beiersdorfer, P.; Chen, Hui

    2014-11-01T23:59:59.000Z

    This paper describes a new type of x-ray crystal spectrometer, which can be used in combination with gated x-ray detectors to obtain spectra from laser-produced plasmas with a high (sub-ns) time resolution. The spectrometer consists of a convex, spherically bent crystal, which images individual spectral lines as perfectly straight lines across multiple, sequentially gated, strip detectors. Since the Bragg-reflected rays are divergent, the distance between detector and crystal is arbitrary, so that this distance can be appropriately chosen to optimize the experimental arrangement with respect to the detector parameters. The spectrometer concept was verified in proof-of-principle experiments by imaging themore »L?1- and L?2-lines of tungsten, at 9.6735 and 9.96150 keV, from a micro-focus xray tube with a tungsten target onto a two-dimensional pixilated Pilatus detector, using a convex, spherically bent Si-422 crystal with a radius of curvature of 500 mm.« less

  10. Role of defects in BiFeO{sub 3} multiferroic films and their local electronic structure by x-ray absorption spectroscopy

    SciTech Connect (OSTI)

    Ravalia, Ashish; Vagadia, Megha; Solanki, P. S.; Shah, N. A.; Kuberkar, D. G., E-mail: dgkuberkar@rediffmail.com [Department of Physics, Saurashtra University, Rajkot 360 005 (India); Gautam, S.; Chae, K. H. [Nano Material Analysis Centre, Korean Institute of Science and Technology, Seoul 136-79 (Korea, Republic of); Asokan, K. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India)

    2014-10-21T23:59:59.000Z

    Present study reports the role of defects in the electrical transport in BiFeO{sub 3} (BFO) multiferroic films and its local electronic structure investigated by near-edge X-ray absorption fine structure. Defects created by high energy 200?MeV Ag{sup +15} ion irradiation with a fluence of ?5?×?10{sup 11} ions/cm{sup 2} results in the increase in structural strain and reduction in the mobility of charge carriers and enhancement in resistive (I-V) and polarization (P-E) switching behaviour. At higher fluence of ?5?×?10{sup 12} ions/cm{sup 2}, there is a release in the structural strain due to local annealing effect, resulting in an increase in the mobility of charge carriers, which are released from oxygen vacancies and hence suppression in resistive and polarization switching. Near-edge X-ray absorption fine structure studies at Fe L{sub 3,2}- and O K-edges show a significant change in the spectral features suggesting the modifications in the local electronic structure responsible for changes in the intrinsic magnetic moment and electrical transport properties of BFO.

  11. A simple electron time-of-flight spectrometer for ultrafast vacuum ultraviolet photoelectron spectroscopy of liquid solutions

    SciTech Connect (OSTI)

    Arrell, C. A., E-mail: christopher.arrell@epfl.ch; Ojeda, J.; Mourik, F. van; Chergui, M. [Laboratory of Ultrafast Spectroscopy, ISIC, Station 6, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne (Switzerland); Sabbar, M.; Gallmann, L.; Keller, U. [Physics Department, ETH Zurich, 8093 Zurich (Switzerland); Okell, W. A.; Witting, T.; Siegel, T.; Diveki, Z.; Hutchinson, S.; Tisch, J. W.G.; Marangos, J. P. [Department of Physics, The Blackett Laboratory, Imperial College, London SW7 2AZ (United Kingdom); Chapman, R. T.; Cacho, C.; Rodrigues, N.; Turcu, I. C.E.; Springate, E. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxon OX11 0QX (United Kingdom)

    2014-10-15T23:59:59.000Z

    We present a simple electron time of flight spectrometer for time resolved photoelectron spectroscopy of liquid samples using a vacuum ultraviolet (VUV) source produced by high-harmonic generation. The field free spectrometer coupled with the time-preserving monochromator for the VUV at the Artemis facility of the Rutherford Appleton Laboratory achieves an energy resolution of 0.65 eV at 40 eV with a sub 100 fs temporal resolution. A key feature of the design is a differentially pumped drift tube allowing a microliquid jet to be aligned and started at ambient atmosphere while preserving a pressure of 10{sup ?1} mbar at the micro channel plate detector. The pumping requirements for photoelectron (PE) spectroscopy in vacuum are presented, while the instrument performance is demonstrated with PE spectra of salt solutions in water. The capability of the instrument for time resolved measurements is demonstrated by observing the ultrafast (50 fs) vibrational excitation of water leading to temporary proton transfer.

  12. PROBING DYNAMICS OF ELECTRON ACCELERATION WITH RADIO AND X-RAY SPECTROSCOPY, IMAGING, AND TIMING IN THE 2002 APRIL 11 SOLAR FLARE

    SciTech Connect (OSTI)

    Fleishman, Gregory D.; Nita, Gelu M.; Gary, Dale E. [Center for Solar-Terrestrial Research, New Jersey Institute of Technology, Newark, NJ 07102 (United States); Kontar, Eduard P. [Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

    2013-05-10T23:59:59.000Z

    Based on detailed analysis of radio and X-ray observations of a flare on 2002 April 11 augmented by realistic three-dimensional modeling, we have identified a radio emission component produced directly at the flare acceleration region. This acceleration region radio component has distinctly different (1) spectrum, (2) light curves, (3) spatial location, and, thus, (4) physical parameters from those of the separately identified trapped or precipitating electron components. To derive evolution of physical parameters of the radio sources we apply forward fitting of the radio spectrum time sequence with the gyrosynchrotron source function with five to six free parameters. At the stage when the contribution from the acceleration region dominates the radio spectrum, the X-ray- and radio-derived electron energy spectral indices agree well with each other. During this time the maximum energy of the accelerated electron spectrum displays a monotonic increase with time from {approx}300 keV to {approx}2 MeV over roughly one minute duration indicative of an acceleration process in the form of growth of the power-law tail; the fast electron residence time in the acceleration region is about 2-4 s, which is much longer than the time of flight and so requires a strong diffusion mode there to inhibit free-streaming propagation. The acceleration region has a relatively strong magnetic field, B {approx} 120 G, and a low thermal density, n{sub e} {approx}< 2 Multiplication-Sign 10{sup 9} cm{sup -3}. These acceleration region properties are consistent with a stochastic acceleration mechanism.

  13. A SMALL PORTABLE DETECTOR HEAD USING MIS-CONTACTED CdTe FOR X-RAY SPECTROMETRY

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    339 A SMALL PORTABLE DETECTOR HEAD USING MIS-CONTACTED CdTe FOR X-RAY SPECTROMETRY P. EICHINGER and the implications of this material for the spectroscopy of gamma rays and X-rays. Instead an arrangement

  14. Electronic structure effects in liquid water studied by photoelectron spectroscopy and density functional theory

    SciTech Connect (OSTI)

    Nordlund, Dennis; Odelius, Michael; Bluhm, Hendrik; Ogasawara, Hirohito; Pettersson, Lars G.M.; Nilsson, Anders

    2008-04-29T23:59:59.000Z

    We present valence photoelectron emission spectra of liquid water in comparison with gas-phase water, ice close to the melting point, low temperature amorphous and crystalline ice. All aggregation states have major electronic structure changes relative to the free molecule, with rehybridization and development of bonding and anti-bonding states accompanying the hydrogen bond formation. Sensitivity to the local structural order, most prominent in the shape and splitting of the occupied 3a{sub 1} orbital, is understood from the electronic structure averaging over various geometrical structures, and reflects the local nature of the orbital interaction.

  15. In situ flame chemistry tracing by imaging photoelectron photoion coincidence spectroscopy

    SciTech Connect (OSTI)

    Oßwald, P.; Köhler, M. [German Aerospace Center (DLR) – Institute of Combustion Technology, Stuttgart 70569 (Germany)] [German Aerospace Center (DLR) – Institute of Combustion Technology, Stuttgart 70569 (Germany); Hemberger, P.; Bodi, A.; Gerber, T. [Molecular Dynamics Group, Paul Scherrer Institut, CH-5232 Villigen (Switzerland)] [Molecular Dynamics Group, Paul Scherrer Institut, CH-5232 Villigen (Switzerland); Bierkandt, T.; Akyildiz, E.; Kasper, T., E-mail: tina.kasper@uni-due.de [Mass Spectrometry in Reactive Flows - Thermodynamics (IVG), University of Duisburg-Essen, Duisburg (Germany)

    2014-02-15T23:59:59.000Z

    Adaptation of a low-pressure flat flame burner with a flame-sampling interface to the imaging photoelectron photoion coincidence spectrometer (iPEPICO) of the VUV beamline at the Swiss Light Source is presented. The combination of molecular-beam mass spectrometry and iPEPICO provides a new powerful analytical tool for the detailed investigation of reaction networks in flames. First results demonstrate the applicability of the new instrument to comprehensive flame diagnostics and the potentially high impact for reaction mechanism development for conventional and alternative fuels. Isomer specific identification of stable and radical flame species is demonstrated with unrivaled precision. Radical detection and identification is achieved for the initial H-abstraction products of fuel molecules as well as for the reaction controlling H, O, and OH radicals. Furthermore, quantitative evaluation of changing species concentrations during the combustion process and the applicability of respective results for kinetic model validation are demonstrated. Utilization of mass-selected threshold photoelectron spectra is shown to ensure precise signal assignment and highly reliable spatial profiles.

  16. Mn Occupations in Ga1-xMnxN Dilute Magnetic Semiconductors Probed by X-Ray Absorption Near-Edge Structure Spectroscopy

    SciTech Connect (OSTI)

    Wei Shiqiang; Yan Wensheng; Sun Zhihu; Liu Qinghua; Zhong Wenjie [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Zhang Xinyi [Department of Physics, Surface Physics Laboratory (National Key Laboratory), Fudan University, 220 Handan Road, Shanghai 200433 (China); Synchrotron Radiation Research Center, Fudan University, 220 Handan Road, Shanghai 200433 (China); Oyanagi, H. [Photonics Research Institute, National Institute of Advanced Industrial Science and Technology 1-1-1 Umezono Tsukuba, Ibaraki 305-8568 (Japan); Wu Ziyu [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100039 (China)

    2007-02-02T23:59:59.000Z

    X-ray absorption near-edge structure (XANES) is used to study the characteristics of different sites of Mn in the Ga1-xMnxN dilute magnetic semiconductor (DMS) with zinc-blende structure. The XANES spectra of representative Mn occupation sites (substitutional MnGa, interstitial MnI, MnGa-MnI dimer and Mn cluster) in GaN lattice are theoretically calculated and compared with experimental results. The substitutional Mn in GaN is characterized by a pre-edge peak at 2.0 eV and a post-edge multiple-scattering peak at 29.1 eV. The peaks shift in position and drop in intensity dramatically for the interstitial MnI and MnGa-MnI dimmer, and disappear completely for Mn clusters. We propose that the distinct characteristics of Mn K-edge XANES spectra for different Mn sites favor to discriminate Mn occupations in GaMnN DMS.

  17. Cryogenic, high-resolution x-ray detector with high count rate capability

    DOE Patents [OSTI]

    Frank, Matthias (Oakland, CA); Mears, Carl A. (Windsor, CA); Labov, Simon E. (Berkeley, CA); Hiller, Larry J. (Livermore, CA); Barfknecht, Andrew T. (Menlo Park, CA)

    2003-03-04T23:59:59.000Z

    A cryogenic, high-resolution X-ray detector with high count rate capability has been invented. The new X-ray detector is based on superconducting tunnel junctions (STJs), and operates without thermal stabilization at or below 500 mK. The X-ray detector exhibits good resolution (.about.5-20 eV FWHM) for soft X-rays in the keV region, and is capable of counting at count rates of more than 20,000 counts per second (cps). Simple, FET-based charge amplifiers, current amplifiers, or conventional spectroscopy shaping amplifiers can provide the electronic readout of this X-ray detector.

  18. Two-dimensional x-ray correlation spectroscopy of remote core states Daniel Healion, Yu Zhang, Jason D. Biggs, Weijie Hua, and Shaul Mukamel

    E-Print Network [OSTI]

    Mukamel, Shaul

    , Jason D. Biggs, Weijie Hua, and Shaul Mukamel Citation: Structural Dynamics 1, 014101 (2014); doi: 10-ray correlation spectroscopy of remote core states Daniel Healion, Yu Zhang, Jason D. Biggs, Weijie Hua, and Shaul

  19. Photoelectron spectroscopy of nickel group dimers: Ni:, PdF, and Ptc Joe Ho,`) Mark L. Polak,b) Kent M. Ervin,C) and W. C. Lineberger

    E-Print Network [OSTI]

    Lineberger, W. Carl

    Photoelectron spectroscopy of nickel group dimers: Ni:, PdF, and Ptc Joe Ho,`) Mark L. Polak are tentatively assigned.Comparison of the nickel group dimers to the coinage metal dimers shedslight on the d orbital contribution to the metal bonding in the nickel group dimers. I. INTRODUCTION Spectroscopicstudy

  20. Cu K-edge X-ray Absorption Spectroscopy Reveals Differential Copper Coordimation Within Amyloid-beta Oligomers Compared to Amyloid-beta Monomers

    SciTech Connect (OSTI)

    J Shearer; P Callan; T Tran; V Szalai

    2011-12-31T23:59:59.000Z

    The fatal neurodegenerative disorder Alzheimer's disease (AD) has been linked to the formation of soluble neurotoxic oligomers of amyloid-{beta} (A{beta}) peptides. These peptides have high affinities for copper cations. Despite their potential importance in AD neurodegeneration few studies have focused on probing the Cu{sup 2+/1+} coordination environment within A{beta} oligomers. Herein we present a Cu K-edge X-ray absorption spectroscopic study probing the copper-coordination environment within oligomers of A{beta}(42) (sequence: DAEFRHDSGYEVHHQKLVFFAEDVGSNKGAIIGLMVGGVVIA). We find that the Cu{sup 2+} cation is contained within a square planar mixed N/O ligand environment within A{beta}(42) oligomers, which is similar to the copper coordination environment of the monomeric forms of {l_brace}Cu{sup II}A{beta}(40){r_brace} and {l_brace}Cu{sup II}A{beta}(16){r_brace}. Reduction of the Cu{sup 2+} cation within the A{beta}(42) oligomers to Cu{sup 1+} yields a highly dioxygen sensitive copper-species that contains Cu{sup 1+} in a tetrahedral coordination geometry. This can be contrasted with monomers of {l_brace}Cu{sup I}A{beta}(40){r_brace} and {l_brace}Cu{sup I}A{beta}(16){r_brace}, which contain copper in a dioxygen inert linear bis-histidine ligand environment [Shearer and Szalai, J. Am. Chem. Soc., 2008, 130, 17826]. The biological implications of these findings are discussed.

  1. Miniature x-ray source

    DOE Patents [OSTI]

    Trebes, James E. (Livermore, CA); Bell, Perry M. (Tracy, CA); Robinson, Ronald B. (Modesto, CA)

    2000-01-01T23:59:59.000Z

    A miniature x-ray source utilizing a hot filament cathode. The source has a millimeter scale size and is capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature source consists of a compact vacuum tube assembly containing the hot filament cathode, an anode, a high voltage feedthru for delivering high voltage to the cathode, a getter for maintaining high vacuum, a connector for initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is fabricated from highly x-ray transparent materials, such as sapphire, diamond, or boron nitride.

  2. Linear accelerator x-ray sources with high duty cycle

    SciTech Connect (OSTI)

    Condron, Cathie; Brown, Craig; Gozani, Tsahi; Langeveld, Willem G. J. [Rapiscan Laboratories, Inc., 520 Almanor Ave. Sunnyvale, CA 94085 (United States); Hernandez, Michael [XScell corp., 2134 Old Middlefield Way, Mountain View, CA 94043 (United States)

    2013-04-19T23:59:59.000Z

    X-ray cargo inspection systems typically use a several-MV pulsed linear accelerator (linac) to produce a bremsstrahlung spectrum of x rays by bombarding a target with electrons. The x rays traverse the cargo and are detected by a detector array. Spectroscopy of the detected x rays is very desirable: if one can determine the spectrum of the transmitted x rays, one can determine the Z of the material they traversed. Even in relatively low-dose modes of operation, thousands of x rays arrive at each detector element during each pulse, unless the x rays are heavily absorbed or scattered by the cargo. For portal or fixed-site systems, dose rates, and therefore x-ray count rates, are even higher. Because of the high x-ray count rate, spectroscopy is impractical in conventional cargo inspection systems, except in certain special cases. For a mobile system, typical pulse durations are a few microseconds, and the number of pulses is on the order of 100 per second, leading to a duty factor of about 0.04%. Clearly, a linear accelerator x-ray source with much higher duty factor would be useful, since then the same number of x rays could be spread out over time, reducing the x-ray count rate. In this paper, we explore the possibility of designing a linear accelerator system, using more or less Conventional Off the Shelf (COTS) components, capable of duty cycles of 1% or greater. A survey was conducted of available linac RF source options and, given the possibilities, calculations were performed for suitable beam centerline designs. Keeping in mind that the size and cost of the accelerator system should be practical for use in a mobile cargo inspection system, only a few options are shown to be reasonably feasible, both requiring the use of klystrons instead of the magnetrons used in conventional systems. An S-Band design appears clearly possible, and there is also a promising X-Band design.

  3. Compact x-ray source and panel

    DOE Patents [OSTI]

    Sampayon, Stephen E. (Manteca, CA)

    2008-02-12T23:59:59.000Z

    A compact, self-contained x-ray source, and a compact x-ray source panel having a plurality of such x-ray sources arranged in a preferably broad-area pixelized array. Each x-ray source includes an electron source for producing an electron beam, an x-ray conversion target, and a multilayer insulator separating the electron source and the x-ray conversion target from each other. The multi-layer insulator preferably has a cylindrical configuration with a plurality of alternating insulator and conductor layers surrounding an acceleration channel leading from the electron source to the x-ray conversion target. A power source is connected to each x-ray source of the array to produce an accelerating gradient between the electron source and x-ray conversion target in any one or more of the x-ray sources independent of other x-ray sources in the array, so as to accelerate an electron beam towards the x-ray conversion target. The multilayer insulator enables relatively short separation distances between the electron source and the x-ray conversion target so that a thin panel is possible for compactness. This is due to the ability of the plurality of alternating insulator and conductor layers of the multilayer insulators to resist surface flashover when sufficiently high acceleration energies necessary for x-ray generation are supplied by the power source to the x-ray sources.

  4. Thermal stability in the blended lithium manganese oxide – Lithium nickel cobalt manganese oxide cathode materials: An in situ time-resolved X-Ray diffraction and mass spectroscopy study

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hu, Enyuan; Bak, Seong Min; Senanayake, Sanjaya D.; Yang, Xiao-Qing; Nam, Kyung-Wan; Zhang, Lulu; Shao, Minhua

    2015-03-01T23:59:59.000Z

    Thermal stabilities of a series of blended LiMn2O4(LMO)-LiNi1/3Co1/3Mn1/3O2 (NCM) cathode materials with different weight ratios were studied by in situ time-resolved X-ray diffraction (XRD) combined with mass spectroscopy in the temperature range of 25°C-580°C under helium atmosphere. Upon heating, the electrochemically delithiated LMO changed into Mn3O4 phase at around 250°C. Formation of MnO with rocksalt structure started at 520°C. This observation is in contrast to the previous report for chemically delithiate LMO in air, in which a process of ?-MnO2 transforming to ?-MnO2 was observed. Oxygen peak was not observed in all cases, presumably as a result of either consumptionmore »by the carbon or detection limit. CO2 profile correlates well with the phase transition and indirectly suggests the oxygen release of the cathode. Introducing NCM into LMO has two effects: first, it makes the high temperature rock-salt phase formation more complicated with more peaks in CO2 profile due to different MO (M = Ni, Mn, Co) phases; secondly, the onset temperature of CO2 release is lowered, implying lowered oxygen release temperature. Upon heating, XRD patterns indicate the NCM part reacts first, followed by the LMO part. This confirms the better thermal stability of LMO over NCM.« less

  5. Thermal stability in the blended lithium manganese oxide – Lithium nickel cobalt manganese oxide cathode materials: An in situ time-resolved X-Ray diffraction and mass spectroscopy study

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hu, Enyuan [Brookhaven National Lab. (BNL), Upton, NY (United States); Bak, Seong Min [Brookhaven National Lab. (BNL), Upton, NY (United States); Senanayake, Sanjaya D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Yang, Xiao-Qing [Dongguk Univ., Seoul (Korea, Republic of). Dept. of Energy and Materials Engineering; Nam, Kyung-Wan [Dongguk Univ., Seoul (Korea, Republic of). Dept. of Energy and Materials Engineering] (ORCID:0000000162786369); Zhang, Lulu [Hong Kong Univ. of Science and Technology, Clear Water Bay (Hong Kong); Shao, Minhua

    2015-03-01T23:59:59.000Z

    Thermal stabilities of a series of blended LiMn2O4(LMO)-LiNi1/3Co1/3Mn1/3O2 (NCM) cathode materials with different weight ratios were studied by in situ time-resolved X-ray diffraction (XRD) combined with mass spectroscopy in the temperature range of 25°C-580°C under helium atmosphere. Upon heating, the electrochemically delithiated LMO changed into Mn3O4 phase at around 250°C. Formation of MnO with rocksalt structure started at 520°C. This observation is in contrast to the previous report for chemically delithiate LMO in air, in which a process of ?-MnO2 transforming to ?-MnO2 was observed. Oxygen peak was not observed in all cases, presumably as a result of either consumption by the carbon or detection limit. CO2 profile correlates well with the phase transition and indirectly suggests the oxygen release of the cathode. Introducing NCM into LMO has two effects: first, it makes the high temperature rock-salt phase formation more complicated with more peaks in CO2 profile due to different MO (M = Ni, Mn, Co) phases; secondly, the onset temperature of CO2 release is lowered, implying lowered oxygen release temperature. Upon heating, XRD patterns indicate the NCM part reacts first, followed by the LMO part. This confirms the better thermal stability of LMO over NCM.

  6. Focused X-ray source

    DOE Patents [OSTI]

    Piestrup, M.A.; Boyers, D.G.; Pincus, C.I.; Maccagno, P.

    1990-08-21T23:59:59.000Z

    Disclosed is an intense, relatively inexpensive X-ray source (as compared to a synchrotron emitter) for technological, scientific, and spectroscopic purposes. A conical radiation pattern produced by a single foil or stack of foils is focused by optics to increase the intensity of the radiation at a distance from the conical radiator. 8 figs.

  7. Strong electron correlation in UO{sub 2}{sup ?}: A photoelectron spectroscopy and relativistic quantum chemistry study

    SciTech Connect (OSTI)

    Li, Wei-Li; Jian, Tian; Lopez, Gary V.; Wang, Lai-Sheng, E-mail: lai-sheng-wang@brown.edu [Department of Chemistry, Brown University, Providence, Rhode Island 02912 (United States)] [Department of Chemistry, Brown University, Providence, Rhode Island 02912 (United States); Su, Jing [Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing 100084 (China) [Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing 100084 (China); Division of Nuclear Materials Science and Engineering, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China and Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Chinese Academy of Sciences, Shanghai 201800 (China); Hu, Han-Shi; Cao, Guo-Jin; Li, Jun, E-mail: junli@tsinghua.edu.cn [Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing 100084 (China)] [Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing 100084 (China)

    2014-03-07T23:59:59.000Z

    The electronic structures of actinide systems are extremely complicated and pose considerable challenges both experimentally and theoretically because of significant electron correlation and relativistic effects. Here we report an investigation of the electronic structure and chemical bonding of uranium dioxides, UO{sub 2}{sup ?} and UO{sub 2}, using photoelectron spectroscopy and relativistic quantum chemistry. The electron affinity of UO{sub 2} is measured to be 1.159(20) eV. Intense detachment bands are observed from the UO{sub 2}{sup ?} low-lying (7s?{sub g}){sup 2}(5f?{sub u}){sup 1} orbitals and the more deeply bound O2p-based molecular orbitals which are separated by a large energy gap from the U-based orbitals. Surprisingly, numerous weak photodetachment transitions are observed in the gap region due to extensive two-electron transitions, suggesting strong electron correlations among the (7s?{sub g}){sup 2}(5f?{sub u}){sup 1} electrons in UO{sub 2}{sup ?} and the (7s?{sub g}){sup 1}(5f?{sub u}){sup 1} electrons in UO{sub 2}. These observations are interpreted using multi-reference ab initio calculations with inclusion of spin-orbit coupling. The strong electron correlations and spin-orbit couplings generate orders-of-magnitude more detachment transitions from UO{sub 2}{sup ?} than expected on the basis of the Koopmans’ theorem. The current experimental data on UO{sub 2}{sup ?} provide a long-sought opportunity to arbitrating various relativistic quantum chemistry methods aimed at handling systems with strong electron correlations.

  8. Producing X-rays at the APS

    ScienceCinema (OSTI)

    None

    2013-04-19T23:59:59.000Z

    An introduction and overview of the Advanced Photon Source at Argonne National Laboratory, the technology that produces the brightest X-ray beams in the Western Hemisphere, and the research carried out by scientists using those X-rays.

  9. Lensless X-Ray Imaging in Reflection

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    X-Ray Imaging in Reflection Print The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs...

  10. APS X-rays Reveal Picasso's Secret

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    | 2003 | 2002 | 2001 2000 Subscribe to APS News rss feed APS X-rays Reveal Picasso's Secret OCTOBER 15, 2012 Bookmark and Share X-rays reveal that Picasso's "Old Guitarist," at...

  11. Spectral analysis of X-ray binaries

    E-Print Network [OSTI]

    Fridriksson, Joel Karl

    2011-01-01T23:59:59.000Z

    In this thesis, I present work from three separate research projects associated with observations of X-ray binaries. Two of those revolve around spectral characteristics of neutron star low-mass X-ray binaries (NS-LMXBs), ...

  12. Phase-sensitive X-ray imager

    DOE Patents [OSTI]

    Baker, Kevin Louis

    2013-01-08T23:59:59.000Z

    X-ray phase sensitive wave-front sensor techniques are detailed that are capable of measuring the entire two-dimensional x-ray electric field, both the amplitude and phase, with a single measurement. These Hartmann sensing and 2-D Shear interferometry wave-front sensors do not require a temporally coherent source and are therefore compatible with x-ray tubes and also with laser-produced or x-pinch x-ray sources.

  13. X-ray Absorption Spectroscopy and Density Functional Theory Studies of [(H3buea)FeIII-X]n1 (X= S2-, O2-,OH-): Comparison of Bonding and Hydrogen Bonding in Oxo and Sulfido Complexes

    SciTech Connect (OSTI)

    Dey, Abhishek; Hocking, Rosalie K.; /Stanford U., Chem. Dept.; Larsen, Peter; Borovik, Andrew S.; /Kansas U.; Hodgson, Keith O.; Hedman, Britt; Solomon, Edward I.; /SLAC,

    2006-09-27T23:59:59.000Z

    Iron L-edge, iron K-edge, and sulfur K-edge X-ray absorption spectroscopy was performed on a series of compounds [Fe{sup III}H{sub 3}buea(X)]{sup n-} (X = S{sup 2-}, O{sup 2-}, OH{sup -}). The experimentally determined electronic structures were used to correlate to density functional theory calculations. Calculations supported by the data were then used to compare the metal-ligand bonding and to evaluate the effects of H-bonding in Fe{sup III}-O vs Fe{sup III-}S complexes. It was found that the Fe{sup III-}O bond, while less covalent, is stronger than the FeIII-S bond. This dominantly reflects the larger ionic contribution to the Fe{sup III-}O bond. The H-bonding energy (for three H-bonds) was estimated to be -25 kcal/mol for the oxo as compared to -12 kcal/mol for the sulfide ligand. This difference is attributed to the larger charge density on the oxo ligand resulting from the lower covalency of the Fe-O bond. These results were extended to consider an Fe{sup IV-}O complex with the same ligand environment. It was found that hydrogen bonding to Fe{sup IV-}O is less energetically favorable than that to Fe{sup III-}O, which reflects the highly covalent nature of the Fe{sup IV-}O bond.

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

    SciTech Connect (OSTI)

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

    2012-07-15T23:59:59.000Z

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

  15. Singlet-Triplet Splittings in CX2 (X ) F, Cl, Br, I) Dihalocarbenes via Negative Ion Photoelectron Spectroscopy

    E-Print Network [OSTI]

    Lineberger, W. Carl

    Singlet-Triplet Splittings in CX2 (X ) F, Cl, Br, I) Dihalocarbenes via Negative Ion Photoelectron2, and CI2. In addition to the long list of theoretical studies on CX2 (X ) F, Cl, Br, I

  16. Extending The Methodology Of X-ray Crystallography To Allow X-ray

    E-Print Network [OSTI]

    Miao, Jianwei "John"

    , the radiation damage. While the radiation damage problem can be mitigated somewhat by using cryogenic techniques resolution without serious radiation damage to the specimens. Although X-ray crystallography becomesExtending The Methodology Of X-ray Crystallography To Allow X-ray Microscopy Without X-ray Optics

  17. X-Ray Absorption Spectroscopy of Metallobiomolecules

    E-Print Network [OSTI]

    Scott, Robert A.

    by the Center for Metalloenzyme Studies (CMS) at the University of Georgia, Athens. Reference Material: Shulman information at the supramolecular to macromolecular level, One-dimensional (1°) molecular level information

  18. X-Ray Absorption Spectroscopy of Metallobiomolecules

    E-Print Network [OSTI]

    Scott, Robert A.

    by the Center for Metalloenzyme Studies (CMS) at the University of Georgia, Athens. Reference Material: Shulman at the supramolecular to macromolecular level, One-dimensional (1°) molecular level information is available through

  19. SMB, X-Ray Spectroscopy & Imaging

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Scienceand Requirements RecentlyElectronicResourcesjobs RunningSEABRV2/01/12SMB SMB

  20. Synchronization of x-ray pulses to the pump laser in an ultrafast x-ray facility

    E-Print Network [OSTI]

    Corlett, J.N.; Barry, W.; Byrd, J.M.; Schoenlein, R.; Zholents, A.

    2002-01-01T23:59:59.000Z

    Accurate timing of ultrafast x-ray probe pulses emitted fromOF X-RAY PULSES TO THE PUMP LASER IN AN ULTRAFAST X-RAY

  1. High Resolution X-Ray Scattering at Sector 3, Advanced Photon...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    about 1 meV resolution; momentum resolved inelastic x-ray scattering with about 1 meV resolution (HERIX); Synchrotron Mossbauer spectroscopy with about 10 neV resolution (SMS)....

  2. SciTech Connect: Validations of Time-Resolved X-Ray Emissions...

    Office of Scientific and Technical Information (OSTI)

    Validations of Time-Resolved X-Ray Emissions Spectroscopy for Analysis of Mn-Based Natural and Artifical Sunlight-to-Energy Assemblies Citation Details In-Document Search Title:...

  3. X-ray holography of biological specimens

    SciTech Connect (OSTI)

    Solem, J.C.

    1984-01-01T23:59:59.000Z

    The author reviews the reasons for x-ray imaging of biological specimens and the techniques presently being used for x-ray microscopy. The author points out the advantages of x-ray holography and the difficulties of obtaining the requisite coherence with conventional sources. The author discusses the problems of radiation damage and the remarkable fact that short pulse x-ray sources circumvent these problems and obtain high-resolution images of specimens in the living state. Finally, the author reviews some of the efforts underway to develop high-intensity coherent x-ray sources for the laboratory. 14 references, 5 figures, 2 tables.

  4. Soft X-ray techniques to study mesoscale magnetism

    E-Print Network [OSTI]

    Kortright, Jeffrey B.

    2003-01-01T23:59:59.000Z

    X-Ray Techniques to Study Mesoscale Magnetism Jeffrey B.X-Ray Techniques to Study Mesoscale Magnetism Jeffrey B.

  5. Techniques for synchronization of X-Ray pulses to the pump laser in an ultrafast X-Ray facility

    E-Print Network [OSTI]

    Corlett, J.N.; Doolittle, L.; Schoenlein, R.; Staples, J.; Wilcox, R.; Zholents, A.

    2003-01-01T23:59:59.000Z

    synchronization of ultrafast x-ray pulses produced in theAccurate timing of ultrafast x-ray probe pulses emitted fromOF X-RAY PULSES TO THE PUMP LASER IN AN ULTRAFAST X-RAY

  6. Controlling X-rays With Light

    SciTech Connect (OSTI)

    Glover, Ernie; Hertlein, Marcus; Southworth, Steve; Allison, Tom; van Tilborg, Jeroen; Kanter, Elliot; Krassig, B.; Varma, H.; Rude, Bruce; Santra, Robin; Belkacem, Ali; Young, Linda

    2010-08-02T23:59:59.000Z

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

  7. X-ray Observations of Mrk 231

    E-Print Network [OSTI]

    T. J. Turner

    1998-08-10T23:59:59.000Z

    This paper presents new X-ray observations of Mrk 231, an active galaxy of particular interest due to its large infrared luminosity and the presence of several blueshifted broad absorption line (BAL) systems, a phenomenon observed in a small fraction of QSOs. A ROSAT HRI image of Mrk 231 is presented, this shows an extended region of soft X-ray emission, covering several tens of kpc, consistent with the extent of the host galaxy. An ASCA observation of Mrk 231 is also presented. Hard X-rays are detected but the data show no significant variability in X-ray flux. The hard X-ray continuum is heavily attenuated and X-ray column estimates range from ~ 2 x 10^{22} - 10^{23} cm^{-2} depending on whether the material is assumed to be neutral or ionized, and on the model assumed for the extended X-ray component. These ASCA data provide only the second hard X-ray spectrum of a BAL AGN presented to date. The broad-band spectral-energy-distribution of the source is discussed. While Mrk 231 is X-ray weak compared to Seyfert 1 galaxies, it has an optical-to-X-ray spectrum typical of a QSO.

  8. Confirmation of intrinsic electron gap states at nonpolar GaN(1-100) surfaces combining photoelectron and surface optical spectroscopy

    SciTech Connect (OSTI)

    Himmerlich, M., E-mail: marcel.himmerlich@tu-ilmenau.de; Eisenhardt, A.; Shokhovets, S.; Krischok, S. [Institut für Physik and Institut für Mikro- und Nanotechnologien, TU Ilmenau, PF 100565, 98684 Ilmenau (Germany); Räthel, J.; Speiser, E.; Neumann, M. D.; Navarro-Quezada, A.; Esser, N. [Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Albert-Einstein-Strasse 9, 12489 Berlin (Germany)

    2014-04-28T23:59:59.000Z

    The electronic structure of GaN(1–100) surfaces is investigated in-situ by photoelectron spectroscopy (PES) and reflection anisotropy spectroscopy (RAS). Occupied surface states 3.1?eV below the Fermi energy are observed by PES, accompanied by surface optical transitions found in RAS around 3.3?eV, i.e., below the bulk band gap. These results indicate that the GaN(1–100) surface band gap is smaller than the bulk one due to the existence of intra-gap states, in agreement with density functional theory calculations. Furthermore, the experiments demonstrate that RAS can be applied for optical surface studies of anisotropic crystals.

  9. X-ray transmissive debris shield

    DOE Patents [OSTI]

    Spielman, Rick B. (Albuquerque, NM)

    1994-01-01T23:59:59.000Z

    A composite window structure is described for transmitting x-ray radiation and for shielding radiation generated debris. In particular, separate layers of different x-ray transmissive materials are laminated together to form a high strength, x-ray transmissive debris shield which is particularly suited for use in high energy fluences. In one embodiment, the composite window comprises alternating layers of beryllium and a thermoset polymer.

  10. High speed x-ray beam chopper

    DOE Patents [OSTI]

    McPherson, Armon (Oswego, IL); Mills, Dennis M. (Naperville, IL)

    2002-01-01T23:59:59.000Z

    A fast, economical, and compact x-ray beam chopper with a small mass and a small moment of inertia whose rotation can be synchronized and phase locked to an electronic signal from an x-ray source and be monitored by a light beam is disclosed. X-ray bursts shorter than 2.5 microseconds have been produced with a jitter time of less than 3 ns.

  11. An unresolved X-ray source inside the supernova remnant RCW 86

    E-Print Network [OSTI]

    Jacco Vink; Fabrizio Bocchino; Francesco Damiani; Jelle S. Kaastra

    2000-08-29T23:59:59.000Z

    We report on the discovery of an unresolved X-ray source inside the supernova remnant G315.4-2.3 (RCW 86). The source is located 7' to the Southwest of the geometrical centre and may be close to the actual explosion centre of the supernova, which makes this a candidate for the stellar remnant associated with RCW 86. However, the presence of a possible optical counterpart with $V \\sim 14$ at 3" from the X-ray position and evidence for long term variability means that the source is probably an active star. A better X-ray position and better X-ray spectroscopy along with an identification of the optical source are needed to exclude the X-ray source as a neutron star candidate.

  12. X-ray populations in galaxies

    E-Print Network [OSTI]

    G. Fabbiano

    2005-11-09T23:59:59.000Z

    Today's sensistive, high resolution Chandra X-ray observations allow the study of many populations of X-ray sources. The traditional astronomical tools of photometric diagrams and luminosity functions are now applied to these populations, and provide the means for classifying the X-ray sources and probing their evolution. While overall stellar mass drives the amount of X-ray binaries in old stellar population, the amount of sources in star-forming galaxies is related to the star formation rate. Shart-lived, luminous, high mass binaries (HNXBs) dominate these young populations.

  13. X-ray laser microscope apparatus

    DOE Patents [OSTI]

    Suckewer, Szymon (Princeton, NJ); DiCicco, Darrell S. (Plainsboro, NJ); Hirschberg, Joseph G. (Coral Gables, FL); Meixler, Lewis D. (East Windsor, NJ); Sathre, Robert (Princeton, NJ); Skinner, Charles H. (Lawrenceville, NJ)

    1990-01-01T23:59:59.000Z

    A microscope consisting of an x-ray contact microscope and an optical microscope. The optical, phase contrast, microscope is used to align a target with respect to a source of soft x-rays. The source of soft x-rays preferably comprises an x-ray laser but could comprise a synchrotron or other pulse source of x-rays. Transparent resist material is used to support the target. The optical microscope is located on the opposite side of the transparent resist material from the target and is employed to align the target with respect to the anticipated soft x-ray laser beam. After alignment with the use of the optical microscope, the target is exposed to the soft x-ray laser beam. The x-ray sensitive transparent resist material whose chemical bonds are altered by the x-ray beam passing through the target mater GOVERNMENT LICENSE RIGHTS This invention was made with government support under Contract No. De-FG02-86ER13609 awarded by the Department of Energy. The Government has certain rights in this invention.

  14. Phased Contrast X-Ray Imaging

    ScienceCinema (OSTI)

    Erin Miller

    2012-12-31T23:59:59.000Z

    The Pacific Northwest National Laboratory is developing a range of technologies to broaden the field of explosives detection. Phased contrast X-ray imaging, which uses silicon gratings to detect distortions in the X-ray wave front, may be applicable to mail or luggage scanning for explosives; it can also be used in detecting other contraband, small-parts inspection, or materials characterization.

  15. X-ray source populations in galaxies

    E-Print Network [OSTI]

    G. Fabbiano

    2005-11-16T23:59:59.000Z

    Today's sensitive, high-resolution X-ray observations allow the study of populations of X-ray sources, in the luminosity range of Galactic X-ray binaries, in galaxies as distant as 20-30 Mpc. The traditional astronomical tools of photometric diagrams and luminosity functions are now applied to these populations, providing a direct probe of the evolved binary component of different stellar populations. The study of the X-ray populations of E and S0 galaxies has revamped the debate on the formation and evolution of low-mass X-ray binaries (LMXBs) and on the role of globular clusters in these processes. While overall stellar mass drives the amount of X-ray binaries in old stellar populations, the amount of sources in star forming galaxies is related to the star formation rate. Short-lived, luminous, high-mass binaries (HMXBs) dominate these young populations. The most luminous sources in these systems are the debated ULXs, which have been suggested to be ~100-1000 Msol black holes, but could alternatively include a number of binaries with stellar mass black holes. Very soft sources have also been discovered in many galaxies and their nature is currently being debated. Observations of the deep X-ray sky, and comparison with deep optical surveys, are providing the first evidence of the X-ray evolution of galaxies.

  16. X-ray diffraction and EXAFS analysis of materials for lithium-based rechargeable batteries

    SciTech Connect (OSTI)

    Sharkov, M. D., E-mail: mischar@mail.ioffe.ru; Boiko, M. E.; Bobyl, A. V.; Ershenko, E. M.; Terukov, E. I. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Zubavichus, Y. V. [National Research Centre “Kurchatov Institute” (Russian Federation)

    2013-12-15T23:59:59.000Z

    Lithium iron phosphate LiFePO{sub 4} (triphylite) and lithium titanate Li{sub 4}Ti{sub 5}O{sub 12} are used as components of a number of active materials in modern rechargeable batteries. Samples of these materials are studied by X-ray diffraction and extended X-ray absorption fine structure (EXAFS) spectroscopy. Hypotheses about the phase composition of the analyzed samples are formulated.

  17. The design and construction of a high-resolution velocity-map imaging apparatus for photoelectron spectroscopy studies of size-selected clusters

    SciTech Connect (OSTI)

    León, Iker; Yang, Zheng; Liu, Hong-Tao; Wang, Lai-Sheng, E-mail: Lai-Sheng-Wang@brown.edu [Department of Chemistry, Brown University, Providence, Rhode Island 02912 (United States)

    2014-08-15T23:59:59.000Z

    A new velocity-map imaging apparatus equipped with a laser-vaporization supersonic cluster source and a time-of-flight mass spectrometer is described for high-resolution photoelectron spectroscopy studies of size-selected cluster anions. Vibrationally cold anion clusters are produced using a laser-vaporization supersonic cluster source, size-selected by a time-of-flight mass spectrometer, and then focused co-linearly into the interaction zone of the high-resolution velocity-map imaging (VMI) system. The multilens VMI system is optimized via systematic simulations and can reach a resolution of 1.2 cm{sup ?1} (FWHM) for near threshold electrons while maintaining photoelectron kinetic energy resolutions (?KE/KE) of ?0.53% for higher energy electrons. The new VMI lens has superior focusing power over a large energy range, yielding highly circular images with distortions no larger than 1.0025 between the long and short radii. The detailed design, simulation, construction, testing, and performance of the high-resolution VMI apparatus are presented.

  18. Maskelynite formation via solid-state transformation: Evidence of infrared and x-ray anisotropy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jaret, Steven J.; Ehm, Lars; Woerner, William R.; Phillips, Brian L.; Nekvasil, Hanna; Wright, Shawn P.; Glotch, Timothy D.

    2015-03-01T23:59:59.000Z

    We present optical microscopy, micro-Raman spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, high-energy X-ray total scattering experiments, and micro-Fourier transform infrared (micro-FTIR) spectroscopy on shocked labradorite from the Lonar Crater, India. We show that maskelynite of shock class 2 is structurally more similar to fused glass than to crystalline plagioclase. However, there are slight but significant differences – preservation of original pre-impact igneous zoning, anisotropy at Infrared wavelengths, X-ray anisotropy, and preservation of some intermediate range order – which are all consistent with a solid-state transformation formation of maskelynite.

  19. X-Ray Nanoimaging: Instruments and Methods

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengtheningWildfires may contribute more toConsensusX-RayX-Ray ImagingX-Ray

  20. X-ray-induced electronic structure change in CuIr{sub 2}S{sub 4}

    SciTech Connect (OSTI)

    Gretarsson, H.; Kim, Young-June [Department of Physics, University of Toronto, 60 St. George Street, Toronto, Ontario M5S 1A7 (Canada); Kim, Jungho; Casa, D.; Gog, T. [CMC-XOR, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Choi, K. R. [l-PEM, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Cheong, S. W. [l-PEM, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); R-CEM and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854 (United States)

    2011-09-15T23:59:59.000Z

    The electronic structure of CuIr{sub 2}S{sub 4} is investigated using various bulk-sensitive x-ray spectroscopic methods near the Ir L{sub 3} edge: resonant inelastic x-ray scattering (RIXS), x-ray absorption spectroscopy in the partial fluorescence yield mode, and resonant x-ray emission spectroscopy. A strong RIXS signal (0.75 eV) resulting from a charge-density-wave gap opening is observed below the metal-insulator transition temperature of 230 K. The resultant modification of electronic structure is consistent with the density functional theory prediction. In the spin- and charge-dimer disordered phase induced by x-ray irradiation below 50 K, we find that a broad peak around 0.4 eV appears in the RIXS spectrum.

  1. GEOC Sunday, March 21, 2010 47 -Speciation and release kinetics of cadmium and zinc in paddy soils: Application of X-ray absorption

    E-Print Network [OSTI]

    Sparks, Donald L.

    : Application of X-ray absorption spectroscopy (XAS) Saengdao Khaokaew, Rufus L Chaney, PhD Matt Ginder kinetics, which is the aim of this research. X-ray absorption spectroscopy (XAS) was used to investigate Cd-ray absorption fine structure (EXAFS) spectroscopic data indicates that CdCO3 and Cd-humic complexes

  2. Hard X-ray Fluorescence Measurements of Heteroepitaxial Solid...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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

  3. Using X-Ray Computed Tomography in Pore Structure Characterization...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Using X-Ray Computed Tomography in Pore Structure Characterization for a Berea Sandstone: Resolution Effect. Using X-Ray Computed Tomography in Pore Structure Characterization for...

  4. Manipulating X-rays with Tiny Mirrors | Argonne National Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    for controlling X-rays. MEMS, or microelectromechanical systems, allow shrinking the optics to the microscale creating ultrafast devices for reflecting X-rays at precise times...

  5. Fuel Injection and Spray Research Using X-Ray Diagnostics

    Broader source: Energy.gov (indexed) [DOE]

    temperature ambient (plastic windows) 5 Radiography - Monochromatic x-rays - Absorption of x-rays by the fuel - Ensemble averaged (flux limited) - Room temperature ambient...

  6. Fuel Injection and Spray Research Using X-Ray Diagnostics

    Broader source: Energy.gov (indexed) [DOE]

    by ECN using several different techniques - Silicone molds (Valencia) - X-ray absorption tomography (CAT) - X-Ray phase contrast imaging (Argonne) - Microscopy (Sandia) ...

  7. Columbia University X-Ray Measurements

    E-Print Network [OSTI]

    Columbia University X-Ray Measurements of the Levitated Dipole Experiment J. L. Ellsworth, J. Kesner MIT Plasma Science and Fusion Center D.T. Garnier, A.K. Hansen, M.E. Mauel Columbia University

  8. Small Angle X-Ray Scattering Detector

    DOE Patents [OSTI]

    Hessler, Jan P.

    2004-06-15T23:59:59.000Z

    A detector for time-resolved small-angle x-ray scattering includes a nearly constant diameter, evacuated linear tube having an end plate detector with a first fluorescent screen and concentric rings of first fiber optic bundles for low angle scattering detection and an annular detector having a second fluorescent screen and second fiber optic bundles concentrically disposed about the tube for higher angle scattering detection. With the scattering source, i.e., the specimen under investigation, located outside of the evacuated tube on the tube's longitudinal axis, scattered x-rays are detected by the fiber optic bundles, to each of which is coupled a respective photodetector, to provide a measurement resolution, i.e., dq/q, where q is the momentum transferred from an incident x-ray to an x-ray scattering specimen, of 2% over two (2) orders of magnitude in reciprocal space, i.e., qmax/qmin approx=lO0.

  9. Lensless X-Ray Imaging in Reflection

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Imaging in Reflection Print Wednesday, 26 October 2011 00:00 The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field...

  10. X-ray source for mammography

    DOE Patents [OSTI]

    Logan, Clinton M. (Pleasanton, CA)

    1994-01-01T23:59:59.000Z

    An x-ray source utilizing anode material which shifts the output spectrum to higher energy and thereby obtains higher penetrating ability for screening mammography application, than the currently utilized anode material. The currently used anode material (molybdenum) produces an energy x-ray spectrum of 17.5/19.6 keV, which using the anode material of this invention (e.g. silver, rhodium, and tungsten) the x-ray spectrum would be in the 20-35 keV region. Thus, the anode material of this invention provides for imaging of breasts with higher than average x-ray opacity without increase of the radiation dose, and thus reduces the risk of induced breast cancer due to the radiation dose administered for mammograms.

  11. X-ray grid-detector apparatus

    DOE Patents [OSTI]

    Boone, John M. (Folsom, CA); Lane, Stephen M. (Oakland, CA)

    1998-01-27T23:59:59.000Z

    A hybrid grid-detector apparatus for x-ray systems wherein a microchannel plate structure has an air-interspaced grid portion and a phosphor/optical fluid-filled grid portion. The grids are defined by multiple adjacent channels separated by lead-glass septa. X-rays entering the air-interspaced grid portion at an angle of impingement upon the septa are attenuated, while non-impinging x-rays pass through to the phosphor/fluid filled portion. X-ray energy is converted to luminescent energy in the phosphor/fluid filled portion and the resultant beams of light are directed out of the phosphor/optical fluid filled portion to an imaging device.

  12. X-ray source for mammography

    DOE Patents [OSTI]

    Logan, C.M.

    1994-12-20T23:59:59.000Z

    An x-ray source is described utilizing anode material which shifts the output spectrum to higher energy and thereby obtains higher penetrating ability for screening mammography application, than the currently utilized anode material. The currently used anode material (molybdenum) produces an energy x-ray spectrum of 17.5/19.6 keV, which using the anode material of this invention (e.g. silver, rhodium, and tungsten) the x-ray spectrum would be in the 20-35 keV region. Thus, the anode material of this invention provides for imaging of breasts with higher than average x-ray opacity without increase of the radiation dose, and thus reduces the risk of induced breast cancer due to the radiation dose administered for mammograms. 6 figures.

  13. Principles of X-ray Navigation

    SciTech Connect (OSTI)

    Hanson, John Eric; /SLAC

    2006-03-17T23:59:59.000Z

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

  14. Compton backscattered collimated x-ray source

    DOE Patents [OSTI]

    Ruth, R.D.; Huang, Z.

    1998-10-20T23:59:59.000Z

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

  15. Compton backscattered collmated X-ray source

    DOE Patents [OSTI]

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

    2000-01-01T23:59:59.000Z

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

  16. Compton backscattered collimated x-ray source

    DOE Patents [OSTI]

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

    1998-01-01T23:59:59.000Z

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

  17. Molecular orientation in soft matter thin films studied by resonant soft X-ray reflectivity

    SciTech Connect (OSTI)

    Mezger, Markus; Jerome, Blandine; Kortright, Jeffrey B.; Valvidares, Manuel; Gullikson, Eric; Giglia, Angelo; Mahne, Nicola; Nannarone, Stefano

    2011-01-12T23:59:59.000Z

    We present a technique to study depth profiles of molecular orientation in soft matter thin films with nanometer resolution. The method is based on dichroism in resonant soft X-ray reflectivity using linear s- and p-polarization. It combines the chemical sensitivity of Near-Edge X-ray Absorption Fine Structure spectroscopy to specific molecular bonds and their orientation relative to the polarization of the incident beam with the precise depth profiling capability of X-ray reflectivity. We demonstrate these capabilities on side chain liquid crystalline polymer thin films with soft X-ray reflectivity data at the carbon K edge. Optical constants of the anisotropic refractive index ellipsoid were obtained from a quantitative analysis using the Berreman formalism. For films up to 50 nm thickness we find that the degree of orientation of the long axis exhibits no depth variation and isindependent of the film thickness.

  18. Photosynthesis and structure of electroless Ni-P films by synchrotron x-ray irradiation

    SciTech Connect (OSTI)

    Hsu, P.-C.; Wang, C.-H.; Yang, T.-Y.; Hwu, Y.-K.; Lin, C.-S.; Chen, C.-H.; Chang, L.-W.; Seol, S.-K.; Je, J.-H.; Margaritondo, G. [Institute of Physics, Academia Sinica, NanKang, Taipei 115, Taiwan and Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan (China); Institute of Physics, Academia Sinica, NanKang, Taipei 115, Taiwan (China); Institute of Physics, Academia Sinica, NanKang, Taipei 115, Taiwan (China); Department of Engineering and System Science, National Tsing Hua University, Hsinchu, 300, Taiwan (China) and Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung 202, Taiwan (China); Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan (China); Kinsus Interconnect Technology Co., Taoyuang 327, Taiwan (China); Department of Materials Science and Optoelectronic Engineering, National Sun Yat-Sen University, Kaoshung 804, Taiwan (China); X-ray Imaging Center, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of) and Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea); Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)

    2007-05-15T23:59:59.000Z

    The authors describe an electroless deposition method for thin films, based on the irradiation by an x-ray beam emitted by a synchrotron source. Specifically, Ni-P films were deposited at room temperature. This synthesis is a unique combination of photochemical and electrochemical processes. The influence of the pH value on the formation and structural properties of the films was examined by various characterization tools including scanning electron microscopy, x-ray diffraction, and x-ray absorption spectroscopy. Real time monitoring of the deposition process by coherent x-ray microscopy reveals that the formation of hydrogen bubbles leads to a self-catalysis effect without a preexisting catalyst. The mechanisms underlying the deposition process are discussed in details.

  19. Temperature-dependent Raman and ultraviolet photoelectron spectroscopy studies on phase transition behavior of VO{sub 2} films with M1 and M2 phases

    SciTech Connect (OSTI)

    Okimura, Kunio, E-mail: okifn@keyaki.cc.u-tokai.ac.jp; Hanis Azhan, Nurul [Graduate School of Engineering, Tokai University, Hiratsuka 259-1292 (Japan); Hajiri, Tetsuya [UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585 (Japan); Graduate School of Engineering, Nagoya University, Nagoya 464-8603 (Japan); Kimura, Shin-ichi [UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585 (Japan); Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871 (Japan); Zaghrioui, Mustapha; Sakai, Joe [GREMAN, UMR 7347 CNRS, Université François Rabelais de Tours, Parc de Grandmont, 37200 Tours (France)

    2014-04-21T23:59:59.000Z

    Structural and electronic phase transitions behavior of two polycrystalline VO{sub 2} films, one with pure M1 phase and the other with pure M2 phase at room temperature, were investigated by temperature-controlled Raman spectroscopy and ultraviolet photoelectron spectroscopy (UPS). We observed characteristic transient dynamics in which the Raman modes at 195?cm{sup ?1} (V-V vibration) and 616?cm{sup ?1} (V-O vibration) showed remarkable hardening along the temperature in M1 phase film, indicating the rearrangements of V-V pairs and VO{sub 6} octahedra. It was also shown that the M1 Raman mode frequency approached those of invariant M2 peaks before entering rutile phase. In UPS spectra with high energy resolution of 0.03?eV for the M2 phase film, narrower V{sub 3d} band was observed together with smaller gap compared to those of M1 phase film, supporting the nature of Mott insulator of M2 phase even in the polycrystalline film. Cooperative behavior of lattice rearrangements and electronic phase transition was suggested for M1 phase film.

  20. Transient x-ray diffraction and its application to materials science and x-ray optics

    SciTech Connect (OSTI)

    Hauer, A.A.; Kopp, R.; Cobble, J.; Kyrala, G.; Springer, R. [and others

    1997-12-01T23:59:59.000Z

    Time resolved x-ray diffraction and scattering have been applied to the measurement of a wide variety of physical phenomena from chemical reactions to shock wave physics. Interest in this method has heightened in recent years with the advent of versatile, high power, pulsed x-ray sources utilizing laser plasmas, electron beams and other methods. In this article, we will describe some of the fundamentals involved in time resolved x-ray diffraction, review some of the history of its development, and describe some recent progress in the field. In this article we will emphasize the use of laser-plasmas as the x-ray source for transient diffraction.

  1. Photoelectron spectroscopy of f-element organometallic complexes. 6. Electronic structure of tetrakis(cyclopentadienyl)actinide complexes

    SciTech Connect (OSTI)

    Bursten, B.E.; Casarin, M.; DiBella, S.; Fang, A.; Fragala, I.L.

    1985-07-03T23:59:59.000Z

    A description of the electronic structure of M(eta/sup 5/-C/sub 5/H/sub 4/CH/sub 3/)/sub 4/ (M = Th, U) complexes as based upon He I and He II photoelectron spectra and relativistic X..cap alpha..-SW calculations is presented. Despite the true S/sub 4/ symmetry of the molecules, the outermost MO's are grouped as if the complexes have a pure tetrahedral ligation environment. As a consequence, donation to empty metal orbitals appears to be highly dominated by the symmetry requirements. The HOMO in Cp'/sub 4/U is almost pure 5f in character, and the corresponding /sup 2/F/sub 5/2/ final state produced upon ionization is split by operation of a T/sub d/ ligand field. The relative intensity variations observed on passing from He I to He II spectra are quite unexpected. It appears that the He II increases of PE signals due to MO's having large metal 6d character are greater than those due to MO's having comparable 5f admixture.

  2. Radial distribution function in x-ray-absorption fine structure

    SciTech Connect (OSTI)

    Stern, E.A.; Ma, Y.; Hanske-Petitpierre, O. (Department of Physics FM-15, University of Washington, Seattle, Washington 98195 (United States)); Bouldin, C.E. (National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States))

    1992-07-01T23:59:59.000Z

    It has been argued that, in systems that have disorder too large to be described by a Gaussian, x-ray-absorption fine-structure (XAFS) spectroscopy alone cannot define the radial distribution function (RDF) because of the lack of low-{ital k} data. We show that the low-{ital k} data can, under certain conditions, be reconstructed using cumulant expansions, which give the correct functional form. This allows XAFS to determine unbiased single-shell RDF's in cases of moderate disorder, without assuming a particular model for the RDF. Some examples are given to illustrate the technique and its limitations.

  3. X-ray Detection from Bona-fide and Candidate Brown Dwarfs in the Rho Ophiuchi Cloud with Chandra

    E-Print Network [OSTI]

    Kensuke Imanishi; Masahiro Tsujimoto; Katsuji Koyama

    2001-08-06T23:59:59.000Z

    We present results of an X-ray search from bona-fide and candidate brown dwarfs in the Rho Ophiuchi cloud cores with the Chandra X-ray Observatory. The selected areas are two fields near the cloud center and are observed with the ACIS-I array of a 17'x17' size and a ~100 ks exposure. Among 18 bona-fide and candidate brown dwarfs listed by the infrared spectroscopy, we find X-ray emission from 7 sources above 99.9% confidence level. Therefore ~40% of the infrared-selected brown dwarfs in this cloud emit X-rays. For the brightest 4 sources, the X-ray spectra are made and are fitted with a thin-thermal plasma model of a temperature 1-2.5 keV. The X-rays are also time variable with rapid flares from 2 of the brown dwarfs. Assuming 2 keV temperature and using the empirical relation of Av vs. NH, we estimate the X-ray luminosity or its upper limit of the other faint or non-X-ray sources. The X-ray luminosity (Lx) of the X-ray-detected sources is in the range of 0.3-90x10^28 ergs s^-1, while the luminosity ratio of X-ray to bolometric (Lx/Lbol) is 10^-3 - 10^-5, similar to those of low-mass pre-main-sequence and dMe stars. All these results suggest that the X-ray origin of brown dwarfs is the same as low-mass stars; strong magnetic activity at the stellar surface.

  4. Using in situ X-ray absorption spectroscopy to study the local structure and oxygen ion conduction mechanism in (La{sub 0.6}Sr{sub 0.4})(Co{sub 0.2}Fe{sub 0.8})O{sub 3-{delta}}

    SciTech Connect (OSTI)

    Itoh, Takanori, E-mail: tknitoh@seimichemical.co.jp [AGC SeimiChemical Co., Ltd., 3-2-10 Chigasaki, Chigasaki City, Kanagawa 253-8585 (Japan); Nakayama, Masanobu [Department of Materials Science and Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya-city, Aichi 466-8555 (Japan)

    2012-08-15T23:59:59.000Z

    To study the local structure and oxygen ion conduction mechanism in (La{sub 0.6}Sr{sub 0.4})(Co{sub 0.2}Fe{sub 0.8})O{sub 3-{delta}} (LSCF) as a function of the oxygen partial pressure (P(O{sub 2})), in situ the Co and Fe K-edge X-ray absorption spectroscopy (XAS) was measured at elevated temperatures of 900 and 1000 K. The reduction of the Co and Fe valence, i.e., the oxygen content (3-{delta}) in LSCF, followed the change of P(O{sub 2}) from 1 to 10{sup -4} atm during{approx}4000 s. The quantitative analysis of the X-ray absorption near edge structure (XANES) and the extended X-ray absorption fine structure (EXAFS) indicated that the Fe valence was higher than the Co valence at oxidative condition ({delta} Almost-Equal-To 0) in LSCF. Whereas the Co valence decreased more than the Fe valence after reduction of P(O{sub 2}) at both 900 and 1000 K. From the relaxation plots of the valence and the oxygen content (3-{delta}) for Co and Fe after changing P(O{sub 2}), we successfully determined D{sub chem} and E{sub a} of an oxygen ion migration around Co and Fe in LSCF. A structural model with and without oxygen vacancies and an oxygen ion conduction mechanism for LSCF are proposed based on these results. - Graphical abstract: A structural model with and without oxygen vacancies, and the oxygen ion conduction mechanism of LSCF were speculated. In other words, oxygen vacancies would form more preferentially around Co than Fe from the results of in situ XAS analysis during reduction, and oxygen ions needs to pass through at the vicinity of Fe from the results of D{sub chem} and E{sub a}. Highlights: Black-Right-Pointing-Pointer Study of the oxygen ion conduction mechanism in (La{sub 0.6}Sr{sub 0.4})(Co{sub 0.2}Fe{sub 0.8})O{sub 3-{delta}} (LSCF). Black-Right-Pointing-Pointer Using in situ X-ray absorption for study of valence and oxygen diffusion coefficient. Black-Right-Pointing-Pointer The oxygen vacancies should be preferentially localized around Co in LSCF. Black-Right-Pointing-Pointer The values of the dynamics parameters for Co and Fe are close to each other.

  5. Electronic structure and spectroscopy of nucleic acid bases: Ionization energies, ionization-induced structural changes, and photoelectron spectra

    SciTech Connect (OSTI)

    Bravaya, Ksenia B.; Kostko, Oleg; Dolgikh, Stanislav; Landau, Arie; Ahmed, Musahid; Krylov, Anna I.

    2010-08-02T23:59:59.000Z

    We report high-level ab initio calculations and single-photon ionization mass spectrometry study of ionization of adenine (A), thymine (T), cytosine (C) and guanine (G). For thymine and adenine, only the lowest-energy tautomers were considered, whereas for cytosine and guanine we characterized five lowest-energy tautomeric forms. The first adiabatic and several vertical ionization energies were computed using equation-of-motion coupled-cluster method for ionization potentials with single and double substitutions. Equilibrium structures of the cationic ground states were characterized by DFT with the {omega}B97X-D functional. The ionization-induced geometry changes of the bases are consistent with the shapes of the corresponding molecular orbitals. For the lowest-energy tautomers, the magnitude of the structural relaxation decreases in the following series G > C > A > T, the respective relaxation energies being 0.41, 0.32, 0.25 and 0.20 eV. The computed adiabatic ionization energies (8.13, 8.89, 8.51-8.67 and 7.75-7.87 eV for A,T,C and G, respectively) agree well with the onsets of the photoionization efficiency (PIE) curves (8.20 {+-} 0.05, 8.95 {+-} 0.05, 8.60 {+-} 0.05 and 7.75 {+-} 0.05 eV). Vibrational progressions for the S{sub 0}-D{sub 0} vibronic bands computed within double-harmonic approximation with Duschinsky rotations are compared with previously reported experimental photoelectron spectra.

  6. Negative Ion Photoelectron Spectroscopy Confirms the Prediction that (CO)5 and (CO)6 Each Has a Singlet Ground State

    SciTech Connect (OSTI)

    Bao, Xiaoguang; Hrovat, David; Borden, Weston; Wang, Xue B.

    2013-03-20T23:59:59.000Z

    Cyclobutane-1,2,3,4-tetraone has been both predicted and found to have a triplet ground state, in which a b2g MO and an a2u MO is each singly occupied. In contrast, (CO)5 and (CO)6 have each been predicted to have a singlet ground state. This prediction has been tested by generating the (CO)5 - and (CO)6 - anions in the gas-phase by electrospray vaporization of solutions of, respectively, the croconate (CO)52- and rhodizonate (CO)62- dianions. The negative ion photoelectron (NIPE) spectra of the (CO)5•- radical anion give electron affinity (EA) = 3.830 eV and a singlet ground state for (CO)5, with the triplet higher in energy by 0.850 eV (19.6 kcal/mol). The NIPE spectra of the (CO)6•- radical anion give EA = 3.785 eV and a singlet ground state for (CO)6, with the triplet higher in energy by 0.915 eV (21.1 kcal/mol). (RO)CCSD(T)/aug-cc-pVTZ//(U)B3LYP/6-311+G(2df) calculations give EA values that are only ca. 1 kcal/mol lower than those measured and EST values that are only 2 - 3 kcal/mol higher than those obtained from the NIPE spectra. Thus, the calculations support the interpretations of the NIPE spectra and the finding, based on the spectra, that (CO)5 and (CO)6 both have a singlet ground state.

  7. Differential phase contrast X-ray imaging system and components

    DOE Patents [OSTI]

    Stutman, Daniel; Finkenthal, Michael

    2014-07-01T23:59:59.000Z

    A differential phase contrast X-ray imaging system includes an X-ray illumination system, a beam splitter arranged in an optical path of the X-ray illumination system, and a detection system arranged in an optical path to detect X-rays after passing through the beam splitter.

  8. Reflection soft X-ray microscope and method

    DOE Patents [OSTI]

    Suckewer, S.; Skinner, C.H.; Rosser, R.

    1993-01-05T23:59:59.000Z

    A reflection soft X-ray microscope is provided by generating soft X-ray beams, condensing the X-ray beams to strike a surface of an object at a predetermined angle, and focusing the X-ray beams reflected from the surface onto a detector, for recording an image of the surface or near surface features of the object under observation.

  9. Nonlinear X-ray Compton Scattering

    E-Print Network [OSTI]

    Fuchs, Matthias; Chen, Jian; Ghimire, Shambhu; Shwartz, Sharon; Kozina, Michael; Jiang, Mason; Henighan, Thomas; Bray, Crystal; Ndabashimiye, Georges; Bucksbaum, P H; Feng, Yiping; Herrmann, Sven; Carini, Gabriella; Pines, Jack; Hart, Philip; Kenney, Christopher; Guillet, Serge; Boutet, Sebastien; Williams, Garth; Messerschmidt, Marc; Seibert, Marvin; Moeller, Stefan; Hastings, Jerome B; Reis, David A

    2015-01-01T23:59:59.000Z

    X-ray scattering is a weak linear probe of matter. It is primarily sensitive to the position of electrons and their momentum distribution. Elastic X-ray scattering forms the basis of atomic structural determination while inelastic Compton scattering is often used as a spectroscopic probe of both single-particle excitations and collective modes. X-ray free-electron lasers (XFELs) are unique tools for studying matter on its natural time and length scales due to their bright and coherent ultrashort pulses. However, in the focus of an XFEL the assumption of a weak linear probe breaks down, and nonlinear light-matter interactions can become ubiquitous. The field can be sufficiently high that even non-resonant multiphoton interactions at hard X-rays wavelengths become relevant. Here we report the observation of one of the most fundamental nonlinear X-ray-matter interactions, the simultaneous Compton scattering of two identical photons producing a single photon at nearly twice the photon energy. We measure scattered...

  10. X-ray lithography using holographic images

    DOE Patents [OSTI]

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

    1997-01-01T23:59:59.000Z

    Methods for forming X-ray images having 0.25 .mu.m minimum line widths on X-ray sensitive material are presented. A holgraphic image of a desired circuit pattern is projected onto a wafer or other image-receiving substrate to allow recording of the desired image in photoresist material. In one embodiment, the method uses on-axis transmission and provides a high flux X-ray source having modest monochromaticity and coherence requirements. A layer of light-sensitive photoresist material on a wafer with a selected surface is provided to receive the image(s). The hologram has variable optical thickness and variable associated optical phase angle and amplitude attenuation for transmission of the X-rays. A second embodiment uses off-axis holography. The wafer receives the holographic image by grazing incidence reflection from a hologram printed on a flat metal or other highly reflecting surface or substrate. In this second embodiment, an X-ray beam with a high degree of monochromaticity and spatial coherence is required.

  11. X-ray lithography using holographic images

    DOE Patents [OSTI]

    Howells, M.S.; Jacobsen, C.

    1997-03-18T23:59:59.000Z

    Methods for forming X-ray images having 0.25 {micro}m minimum line widths on X-ray sensitive material are presented. A holographic image of a desired circuit pattern is projected onto a wafer or other image-receiving substrate to allow recording of the desired image in photoresist material. In one embodiment, the method uses on-axis transmission and provides a high flux X-ray source having modest monochromaticity and coherence requirements. A layer of light-sensitive photoresist material on a wafer with a selected surface is provided to receive the image(s). The hologram has variable optical thickness and variable associated optical phase angle and amplitude attenuation for transmission of the X-rays. A second embodiment uses off-axis holography. The wafer receives the holographic image by grazing incidence reflection from a hologram printed on a flat metal or other highly reflecting surface or substrate. In this second embodiment, an X-ray beam with a high degree of monochromaticity and spatial coherence is required. 15 figs.

  12. Radiographic X-Ray Pulse Jitter

    SciTech Connect (OSTI)

    Mitton, C. V., Good, D. E., Henderson, D. J., Hogge, K. W.

    2011-01-15T23:59:59.000Z

    The Dual Beam Radiographic Facility consists of two identical radiographic sources. Major components of the machines are: Marx generator, water-filled pulse-forming line (PFL), water-filled coaxial transmission line, three-cell inductive voltage adder, and rod-pinch diode. The diode pulse has the following electrical specifications: 2.25-MV, 60-kA, 60-ns. Each source has the following x-ray parameters: 1-mm-diameter spot size, 4-rad at 1 m, 50-ns full width half max. The x-ray pulse is measured with PIN diode detectors. The sources were developed to produce high resolution images on single-shot, high-value experiments. For this application it is desirable to maintain a high level of reproducibility in source output. X-ray pulse jitter is a key metric for analysis of reproducibility. We will give measurements of x-ray jitter for each machine. It is expected that x-ray pulse jitter is predominantly due to PFL switch jitter, and therefore a correlation of the two will be discussed.

  13. Oscillations During Thermonuclear X-ray Bursts

    E-Print Network [OSTI]

    Tod E. Strohmayer

    2001-01-12T23:59:59.000Z

    High amplitude, nearly coherent X-ray brightness oscillations during thermonuclear X-ray bursts were discovered with the Rossi X-ray Timing Explorer (RXTE) in early 1996. Spectral and timing evidence strongly supports the conclusion that these oscillations are caused by rotational modulation of the burst emission and that they reveal the spin frequency of neutron stars in low mass X-ray binaries, a long sought goal of X-ray astronomy. Studies carried out over the past year have led to the discovery of burst oscillations in four new sources, bringing to ten the number with confirmed burst oscillations. I review the status of our knowledge of these oscillations and indicate how they can be used to probe the physics of neutron stars. For a few burst oscillation sources it has been proposed that the strongest and most ubiquitous frequency is actually the first overtone of the spin frequency and hence that two nearly antipodal hot spots are present on the neutron star. This inference has important implications for both the physics of thermonuclear burning as well as the mass - radius relation for neutron stars, so its confirmation is crucial. I discuss recent attempts to confirm this hypothesis for 4U 1636-53, the source for which a signal at the putative fundamental (290 Hz) has been claimed.

  14. X-RAY SPECTROMETRY X-Ray Spectrom. 2007; 36: 336342

    E-Print Network [OSTI]

    Limburg, Karin E.

    , Chicago, IL 60637, USA 3 Cornell High Energy Synchrotron Source and School of Applied and EngineeringX-RAY SPECTROMETRY X-Ray Spectrom. 2007; 36: 336­342 Published online in Wiley InterScience (www to establish a breakthrough in high-resolution, simultaneous area mapping of multiple trace elements

  15. In Operando X-ray Diffraction and Transmission X-ray Microscopy of Lithium Sulfur Batteries

    E-Print Network [OSTI]

    Cui, Yi

    In Operando X-ray Diffraction and Transmission X-ray Microscopy of Lithium Sulfur Batteries Johanna Information ABSTRACT: Rechargeable lithium-sulfur (Li-S) batteries hold great potential for high of these batteries for commercial use. The two primary obstacles are the solubility of long chain lithium

  16. X-Ray Data from the X-Ray Data Booklet Online

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Thompson, Albert C.; Attwood, David T.; Gullikson, Eric M.; Howells, Malcolm R.; Kortright, Jeffrey B.; Robinson, Arthur L.; Underwood, James H.; Kim, Kwang-Je; Kirz, Janos; Lindau, Ingolf; Pianetta, Piero; Winick, Herman; Williams, Gwyn P.; Scofield, James H.

    The original X-Ray Data Booklet, published in 1985, became a classic reference source. The online version has been significantly revised and updated to reflect today's science. Hundreds of pages of authoritative data provide the x-ray properties of elements, information on synchrotron radiation, scattering processes, optics and detectors, and other related calculations, formulas, and data tables.

  17. Bomb Detection Using Backscattered X-Rays

    SciTech Connect (OSTI)

    Jacobs, J.; Lockwood, G.; Selph, M; Shope, S.; Wehlburg, J.

    1998-10-01T23:59:59.000Z

    Bomb Detection Using Backscattered X-rays* Currently the most common method to determine the contents of a package suspected of containing an explosive device is to use transmission radiography. This technique requires that an x-ray source and film be placed on opposite sides of the package. This poses a problem if the pachge is placed so that only one side is accessible, such as against a wall. There is also a threat to persomel and property since exTlosive devices may be "booby trapped." We have developed a method to x-ray a paclage using backscattered x-rays. This procedure eliminates the use of film behind the target. All of the detection is done from the same side as the source. When an object is subjected to x-rays, some of them iare scattered back towards the source. The backscattenng of x-rays is propordoml to the atomic number (Z) of the material raised to the 4.1 power. This 24"' dependence allows us to easily distinguish between explosives, wires, timer, batteries, and other bomb components. Using transmission radiography-to image the contents of an unknown package poses some undesirable risks. The object must have an x-ray film placed on the side opposite the x-ray source; this cannot be done without moving the package if it has been placed firmly against a wall or pillar. Therefore it would be extremely usefid to be able to image the contents of a package from only one side, without ever having to disturb the package itself. where E is the energy of the incoming x-ray. The volume of x-rays absorbed is important because it is, of course, directly correlated to the intensity of x-mys that will be scattered. Most of the x-rays that scatter will do so in a genemlly forward direction; however, a small percentage do scatter in a backward direction. Figure 1 shows a diagram of the various fates of x-rays directed into an object. The package that was examined in this ex~enment was an attache case made of pressed fiberboardwith a vinyl covering. It was approxirmtely 36 cm wide by 51 cm long by 13 cm deep. The case was placed on an aluminum sheet under the x-ray source. Because of the laborato~ setup, the attache case was rastered in the y-coordinate direction, while the x-ray source mstered in the x-coordinate direction. However, for field use, the x-ray source would of course raster in both the x- and y-coordinate directions, while the object under interrogation would remain stationary and undisturbed. A mobile system for use by law enforcement agencies or bomb disposal squads needs to be portable and somewhat durable. A 300 kV x-ray source should be sufficient for the task requirements and can be mounted on a mobile system. A robotic carriage could be used to transport the x-ray source and the CCD camera to the proximity of the suspect package. The controlling and data analyzing elements of the system' could then be maintained at a &tie distance from the possible explosive. F@re 8 shows a diagram of a conceptual design of a possible system for this type of use. The use of backscattered x-rays for interrogation of packages that may contain explosive devices has been shown to be feasible inthelaboratory. Usinga 150kVx-ray source anddetectors consisting of plastic scintillating material, all bomb components including the wiring were detectable. However, at this time the process requires more time than is desirable for the situations in which it will most likely be needed. Further development of the technology using CCD cameras, rather than the plastic stint illator detectors, shows promise of leading to a much faster system, as well as one with better resolution. Mounting the x- ray source and the CCD camera on a robotic vehicle while keeping the controlling and analyzing components and the opemting personnel a safe distance away from the suspect package will allow such a package to be examined at low risk to human life.

  18. Frontiers in X-Ray Science

    SciTech Connect (OSTI)

    Linda Young

    2011-02-23T23:59:59.000Z

    The year 2010 marked the fiftieth anniversary of the optical laser and the first anniversary of the world's first hard x-ray free-electron laser, the Linac Coherent Light Source (LCLS) at SLAC. This exciting, new accelerator-based source of x-rays provides peak brilliances roughly a billion times greater than currently available from synchrotron sources such as the Advanced Photon Source at Argonne, and thus explores a qualitatively different parameter space. This talk will describe the first experiments at the LCLS aimed at understanding the nature of high intensity x-ray interactions, related applications in ultrafast imaging on the atomic scale and sketch nascent plans for the extension of both linac and storage-ring based photon sources.

  19. The X-ray/submillimetre link

    E-Print Network [OSTI]

    O. Almaini

    2000-01-07T23:59:59.000Z

    It is widely believed that most of the cosmic X-ray background (XRB) is produced by a vast, hitherto undetected population of obscured AGN. Deep X-ray surveys with Chandra and XMM will soon test this hypothesis. Similarly, recent sub-mm surveys with SCUBA have revealed an analogous population of exceptionally luminous, dust-enshrouded {\\em star-forming} galaxies at high redshift. There is now growing evidence for an intimate link between these obscured populations. There are currently large uncertainties in the models, but several independent arguments lead to the conclusion that a significant fraction of the SCUBA sources ($10-30% $) will contain quasars. Recent observational studies of SCUBA survey sources appear to confirm these predictions, although the relative roles of AGN and star-forming activity in heating the dust are unclear. Forthcoming surveys combining X-ray and sub-mm observations will provide a very powerful tool for disentangling these processes.

  20. X-ray atlas of rheumatic diseases

    SciTech Connect (OSTI)

    Dihlmann, W.

    1986-01-01T23:59:59.000Z

    This atlas comprises instructive X-rays of the various inflammatory rheumatic joint diseases in all stages at the extremities and the spinal column. In addition, the complex pattern of the wide range of arthroses, also known as degenerative rheumatic disease is included. Besides the instructive pointers to X-ray diagnosis, the book is also a guide to differential diagnosis. Hence, this book is actually an X-ray atlas of joint diseases in general. Selected Contents: Introduction: What Does ''Rheumatism'' Actually Mean./Radiographic Methodology in Rheumatic Diseases of the Locomotor System/The Mosaic of Arthritis/Adult Rheumatoid Arthritis/Seronegative Spondylarthritis/Classic Collagen Diseases/Enthesiopathies/Gout-Pseudogout

  1. Combined microstructure x-ray optics

    SciTech Connect (OSTI)

    Barbee, T.W. Jr.

    1989-02-01T23:59:59.000Z

    Multilayers are man-made microstructures which vary in depth and are now of sufficient quality to be used as x-ray, soft x-ray and extreme ultraviolet optics. Gratings are man-made in plane microstructures which have been used as optic elements for most of this century. Joining of these two optical microstructures to form combined microstructure optical microstructures to form combined microstructure optical elements has the potential for greatly enhancing both the throughput and the resolution attainable in these spectral ranges. The characteristics of these new optic elements will be presented and compared to experiment with emphasis on the unique properties of these combined microstructures. These results reported are general in nature and not limited to the soft x-ray or extreme ultraviolet spectral domains and also apply to neutrons. 19 refs., 7 figs., 4 tabs.

  2. X-ray reflectivity and surface roughness

    SciTech Connect (OSTI)

    Ocko, B.M.

    1988-01-01T23:59:59.000Z

    Since the advent of high brightness synchrotron radiation sources there has been a phenomenal growth in the use of x-rays as a probe of surface structure. The technique of x-ray reflectivity is particularly relevant to electrochemists since it is capable of probing the structure normal to an electrode surface in situ. In this paper the theoretical framework for x-ray reflectivity is reviewed and the results from previous non-electrochemistry measurements are summarized. These measurements are from the liquid/air interface (CCl/sub 4/), the metal crystal vacuum interface (Au(100)), and from the liquid/solid interface(liquid crystal/silicon). 34 refs., 5 figs.

  3. Scanning Transmission X-ray Microscopy: Applications in Atmospheric Aerosol Research

    SciTech Connect (OSTI)

    Moffet, Ryan C.; Tivanski, Alexei V.; Gilles, Mary K.

    2011-01-20T23:59:59.000Z

    Scanning transmission x-ray microscopy (STXM) combines x-ray microscopy and near edge x-ray absorption fine structure spectroscopy (NEXAFS). This combination provides spatially resolved bonding and oxidation state information. While there are reviews relevant to STXM/NEXAFS applications in other environmental fields (and magnetic materials) this chapter focuses on atmospheric aerosols. It provides an introduction to this technique in a manner approachable to non-experts. It begins with relevant background information on synchrotron radiation sources and a description of NEXAFS spectroscopy. The bulk of the chapter provides a survey of STXM/NEXAFS aerosol studies and is organized according to the type of aerosol investigated. The purpose is to illustrate the current range and recent growth of scientific investigations employing STXM-NEXAFS to probe atmospheric aerosol morphology, surface coatings, mixing states, and atmospheric processing.

  4. Radiobiological studies using gamma and x rays.

    SciTech Connect (OSTI)

    Potter, Charles Augustus; Longley, Susan W.; Scott, Bobby R. [Lovelace Respiratory Research Institute, Albuquerque, NM; Lin, Yong [Lovelace Respiratory Research Institute, Albuquerque, NM; Wilder, Julie [Lovelace Respiratory Research Institute, Albuquerque, NM; Hutt, Julie A. [Lovelace Respiratory Research Institute, Albuquerque, NM; Padilla, Mabel T. [Lovelace Respiratory Research Institute, Albuquerque, NM; Gott, Katherine M. [Lovelace Respiratory Research Institute, Albuquerque, NM

    2013-02-01T23:59:59.000Z

    There are approximately 500 self-shielded research irradiators used in various facilities throughout the U.S. These facilities use radioactive sources containing either 137Cs or 60Co for a variety of biological investigations. A report from the National Academy of Sciences[1] described the issues with security of particular radiation sources and the desire for their replacement. The participants in this effort prepared two peer-reviewed publications to document the results of radiobiological studies performed using photons from 320-kV x rays and 137Cs on cell cultures and mice. The effectiveness of X rays was shown to vary with cell type.

  5. Energy resolved X-ray grating interferometry

    SciTech Connect (OSTI)

    Thuering, T.; Stampanoni, M. [Swiss Light Source, Paul Scherrer Institut, Villigen PSI (Switzerland) [Swiss Light Source, Paul Scherrer Institut, Villigen PSI (Switzerland); Institute for Biomedical Engineering, Swiss Federal Institute of Technology, Zurich (Switzerland); Barber, W. C.; Iwanczyk, J. S. [DxRay, Inc., Northridge, California 91324 (United States)] [DxRay, Inc., Northridge, California 91324 (United States); Seo, Y.; Alhassen, F. [UCSF Physics Research Laboratory, Department of Radiology and Biomedical Imaging, University of California, San Francisco, California 94143 (United States)] [UCSF Physics Research Laboratory, Department of Radiology and Biomedical Imaging, University of California, San Francisco, California 94143 (United States)

    2013-05-13T23:59:59.000Z

    Although compatible with polychromatic radiation, the sensitivity in X-ray phase contrast imaging with a grating interferometer is strongly dependent on the X-ray spectrum. We used an energy resolving detector to quantitatively investigate the dependency of the noise from the spectral bandwidth and to consequently optimize the system-by selecting the best energy band matching the experimental conditions-with respect to sensitivity maximization and, eventually, dose. Further, since theoretical calculations of the spectrum are usually limited due to non-ideal conditions, an energy resolving detector accurately quantifies the spectral changes induced by the interferometer including flux reduction and beam hardening.

  6. X-Ray Nanoimaging: Instruments and Methods

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengtheningWildfires may contribute more toConsensusX-RayX-Ray

  7. Layer-dependent Debye temperature and thermal expansion of Ru(0001) by means of high-energy resolution core-level photoelectron spectroscopy

    SciTech Connect (OSTI)

    Ferrari, Eugenio; Galli, Lorenzo; Miniussi, Elisa; Morri, Maurizio; Panighel, Mirko; Ricci, Maria [Physics Department, University of Trieste, Via Valerio 2, I-34127 Trieste (Italy); Lacovig, Paolo; Lizzit, Silvano [Sincrotrone Trieste S.C.p.A., Strada Statale 14 Km 163.5, 34149 Trieste (Italy); Baraldi, Alessandro [Physics Department, University of Trieste, Via Valerio 2, I-34127 Trieste (Italy); Laboratorio TASC, IOM-CNR, S.S. 14 Km 163.5, I-34149 Trieste (Italy)

    2010-11-15T23:59:59.000Z

    The layer-dependent Debye temperature of Ru(0001) is determined by means of high-energy resolution core-level photoelectron spectroscopy measurements. The possibility to disentangle three different components in the Ru 3d{sub 5/2} spectrum of Ru(0001), originating from bulk, first-, and second-layer atoms, allowed us to follow the temperature evolution of their photoemission line shapes and binding energies. Temperature effects were detected, namely, a lattice thermal expansion and a layer-dependent phonon broadening, which was interpreted within the framework of the Hedin-Rosengren formalism based on the Debye theory. The resulting Debye temperature of the top-layer atoms is 295{+-}10 K, lower than that of the bulk (T=668{+-}5 K) and second-layer (T=445{+-}10 K) atoms. While these results are in agreement with the expected phonon softening at the surface, we show that a purely harmonic description of the motion of the surface atoms is not valid, since anharmonic effects contribute significantly to the position and line shape of the different core-level components.

  8. Photoelectron spectroscopy investigation of the temperature-induced deprotonation and substrate-mediated hydrogen transfer in a hydroxyphenyl-substituted porphyrin

    E-Print Network [OSTI]

    Smykalla, Lars; Mende, Carola; Lang, Heinrich; Knupfer, Martin; Hietschold, Michael

    2015-01-01T23:59:59.000Z

    The temperature dependent stepwise deprotonation of 5,10,15,20-tetra(p-hydroxyphenyl)porphyrin is investigated using photoelectron spectroscopy. An abundance of pyrrolic relative to iminic nitrogen and a decrease in the ratio of the amount of -NH- to -N= with increasing annealing temperature is found. In contrast to the molecules adsorbed on Au(111), on the more reactive Ag(110) surface, partial dissociation of the hydroxyl groups and subsequent diffusion and rebonding of hydrogen to the central nitrogen atoms resulting in a zwitterionic molecule was clearly observed. Moreover, partial C-H bond cleavage and the formation of new covalent bonds with adjacent molecules or the surface starts at a relatively high annealing temperature of 300{\\deg}C. This reaction is identified to occur at the carbon atoms of the pyrrole rings, which leads also to a shift in the N 1s signal and changes in the valence band of the molecules. Our results show that annealing can significantly alter the molecules which were deposited de...

  9. Electronic states of thiophene/phenylene co-oligomers: Extreme-ultra violet excited photoelectron spectroscopy observations and density functional theory calculations

    SciTech Connect (OSTI)

    Kawaguchi, Yoshizo [Research Institute for Innovation in Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565 (Japan); Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Sasaki, Fumio; Mochizuki, Hiroyuki [Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Ishitsuka, Tomoaki; Tomie, Toshihisa [Research Institute of Instrumentation Frontier, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Ootsuka, Teruhisa [Nanoelectronics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Watanabe, Shuji [Graduate School of Science and Engineering, Yamagata University, 1-4-12, Kojirakawa, Yamagata 990-8560 (Japan); Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Shimoi, Yukihiro [Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Yamao, Takeshi; Hotta, Shu [Department of Macromolecular Science and Engineering, Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan)

    2013-02-28T23:59:59.000Z

    We have investigated electronic states in the valence electron bands for the thin films of three thiophene/phenylene co-oligomer (TPCO) compounds, 2,5-bis(4-biphenylyl)thiophene (BP1T), 1,4-bis(5-phenylthiophen-2-yl)benzene (AC5), and 1,4-bis{l_brace}5-[4-(trifluoromethyl)phenyl]thiophen-2-yl{r_brace}benzene (AC5-CF{sub 3}), by using extreme-UV excited photoelectron spectroscopy (EUPS). By comparing both EUPS spectra and secondary electron spectra between AC5 and AC5-CF{sub 3}, we confirm that CF{sub 3} substitution to AC5 deepens valence states by 2 eV, and increases the ionization energy by 3 eV. From the cut-off positions of secondary electron spectra, the work functions of AC5, AC5-CF{sub 3}, and BP1T are evaluated to be 3.8 eV, 4.8 eV, and 4.0 eV, respectively. We calculate molecular orbital (MO) energy levels by the density functional theory and compare results of calculations with those of experiments. Densities of states obtained by broadening MO levels well explain the overall features of experimental EUPS spectra of three TPCOs.

  10. Electronic structure of the heavy-fermion caged compound Ce?Pd??X? (X = Si, Ge) studied by density functional theory and photoelectron spectroscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yamaoka, Hitoshi; Jarrige, Ignace; Schwier, Eike F.; Arita, Masashi; Shimada, Kenya; Tsujii, Naohito; Jiang, Jian; Hayashi, Hirokazu; Iwasawa, Hideaki; Namatame, Hirofumi; et al

    2015-03-01T23:59:59.000Z

    The electronic structure of Ce?Pd??X? (X = Si, Ge) has been studied using detailed density functional theory (DFT) calculations and high-resolution photoelectron spectroscopy (PES) measurements. The orbital decomposition of the electronic structure by DFT calculations indicates that Ce atoms at the (8c) site surrounded by 16 Pd atoms have a more localized nature and a tendency to be magnetic. Ce atoms in the (4a) site surrounded by 12 Pd and 6 X atoms, on the other, show only a negligible magnetic moment. In the photoemission valence-band spectra we observe a strong f? (Ce??) component with a small fraction of f¹more »(Ce³?) component. The spectral weight of f¹ component near the Fermi level Ce?Pd??Si? is stronger than that for Ce?Pd??Ge? at the 4d-4f resonance, suggesting stronger c-f hybridization in the former. This may hint to the origin of the large electronic specific coefficient of Ce?Pd??Si? compared to Ce?Pd??Ge?.« less

  11. Phase I, study of a miniature X-ray source for interstitial radiotherapy of brain metastases

    SciTech Connect (OSTI)

    Douglas, R.M.; Beatty, J.; Biggs, P. [Massachusetts General Hospital, Boston, MA (United States)] [and others] [Massachusetts General Hospital, Boston, MA (United States); and others

    1995-12-31T23:59:59.000Z

    Despite a variety of stereotactic techniques used to increase intracranical local control, dose escalation strategies remain controversial, with respect to therapeutric gain, convenience, and cost effectiveness, in the setting of brain metastases. In this report, we summarize our experience with the safety and efficacy of a new miniature X-ray device for interstitial radiosurgical treatment of intracranial metastatic neoplasms. Although the role of surgical resection of solitary metastases is established, aggressive treatment with proton, gamma knife, and linac radiation therapy for these lesions is under investigation. The new miniature X-ray device offers a very localized, convenient, time and cost efficient means of delivering radiotherapy to these lesions, with lower normal tissue exposure than gamma knife or proton beam techniques. Retreatment of previously irradiated areas are also now under investigation as part of a Phase II trial. The photon radiosurgery system is a miniature battery operated 40 kV x-ray device designed by the Photoelectron Corporation for use in the interstitial treatment of small tumors ({ge}3 cm in diameter) in humans. This 10 cm long, low current, high voltage X-ray generator is easily mounted in a stereotactic frame and produces low energy (10-20 KeV) x-rays to be emitted from the 10 cm long, 3.2 mm diameter probe, after stereotactic insertion into the tumor. Two scintillation detectors positioned on the stereotactic frame near the patient`s scalp monitor radiation. The spherical X-ray beam behaves essentially as a point source, with dose rate nominally 150 cGy/min. at a distance of 10mm, for a beam current of 40 {mu}A and a voltage of 40 kv.

  12. Vacuum space charge effects in sub-picosecond soft X-ray photoemission on a molecular adsorbate layer

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dell'Angela, M.; Anniyev, T.; Beye, M.; Coffee, R.; Föhlisch, A.; Gladh, J.; Kaya, S.; Katayama, T.; Krupin, O.; Nilsson, A.; et al

    2015-03-01T23:59:59.000Z

    Vacuum space charge induced kinetic energy shifts of O 1s and Ru 3d core levels in femtosecond soft X-ray photoemission spectra (PES) have been studied at a free electron laser (FEL) for an oxygen layer on Ru(0001). We fully reproduced the measurements by simulating the in-vacuum expansion of the photoelectrons and demonstrate the space charge contribution of the high-order harmonics in the FEL beam. Employing the same analysis for 400 nm pump-X-ray probe PES, we can disentangle the delay dependent Ru 3d energy shifts into effects induced by space charge and by lattice heating from the femtosecond pump pulse.

  13. SLAC All Access: X-ray Microscope

    ScienceCinema (OSTI)

    Nelson, Johanna; Liu, Yijin

    2014-06-13T23:59:59.000Z

    SLAC physicists Johanna Nelson and Yijin Liu give a brief overview of the X-ray microscope at the Stanford Synchrotron Radiation Lightsource (SSRL) that is helping improve rechargeable-battery technology by letting researchers peek into the inner workings of batteries as they operate.

  14. Femtosecond X-ray protein nanocrystallography

    SciTech Connect (OSTI)

    Chapman, Henry N.; Fromme, Petra; Barty, Anton; White, Thomas A.; Kirian, Richard A.; Aquila, Andrew; Hunter, Mark S.; Schulz, Joachim; DePonte, Daniel P.; Weierstall, Uwe; Doak, R. Bruce; Maia, Filipe R. N. C.; Martin, Andrew V.; Schlichting, Ilme; Lomb, Lukas; Coppola, Nicola; Shoeman, Robert L.; Epp, Sascha W.; Hartmann, Robert; Rolles, Daniel; Rudenko, Artem; Foucar, Lutz; Kimmel, Nils; Weidenspointner, Georg; Holl, Peter; Liang, Mengning; Barthelmess, Miriam; Caleman, Carl; Boutet, Sebastien; Bogan, Michael J.; Krzywinski, Jacek; Bostedt, Christoph; Bajt, Sasa; Gumprecht, Lars; Rudek, Benedikt; Erk, Benjamin; Schmidt, Carlo; Homke, Andre; Reich, Christian; Pietschner, Daniel; Struder, Lothar; Hauser, Gunter; Gorke, Hubert; Ullrich, Joachim; Herrmann, Sven; Schaller, Gerhard; Schopper, Florian; Soltau, Heike; Kuhnel, Kai-Uwe; Messerschmidt, Marc; Bozek, John D.; Hau-Riege, Stefan P.; Frank, Matthias; Hampton, Christina Y.; Sierra, Raymond G.; Starodub, Dmitri; Williams, Garth J.; Hajdu, Janos; Timneanu, Nicusor; Seibert, M. Marvin; Andreasson, Jakob; Rocker, Andrea; Jonsson, Olof; Svenda, Martin; Stern, Stephan; Nass, Karol; Andritschke, Robert; Schroter, Claus-Dieter; Krasniqi, Faton; Bott, Mario; Schmidt, Kevin E.; Wang, Xiaoyu; Grotjohann, Ingo; Holton, James M.; Barends, Thomas R. M.; Neutze, Richard; Marchesini, Stefano; Fromme, Raimund; Schorb, Sebastian; Rupp, Daniela; Adolph, Marcus; Gorkhover, Tais; Andersson, Inger; Hirsemann, Helmut; Potdevin, Guillaume; Graafsma, Heinz; Nilsson, Bjorn; Spence, John C. H.

    2011-01-01T23:59:59.000Z

    X-ray crystallography provides the vast majority of macromolecular structures, but the success of the method relies on growing crystals of sufficient size. In conventional measurements, the necessary increase in X-ray dose to record data from crystals that are too small leads to extensive damage before a diffraction signal can be recorded. It is particularly challenging to obtain large, well-diffracting crystals of membrane proteins, for which fewer than 300 unique structures have been determined despite their importance in all living cells. Here we present a method for structure determination where single-crystal X-ray diffraction ‘snapshots’ are collected from a fully hydrated stream of nanocrystals using femtosecond pulses from a hard-X-ray free-electron laser, the Linac Coherent Light Source. We prove this concept with nanocrystals of photosystem I, one of the largest membrane protein complexes. More than 3,000,000 diffraction patterns were collected in this study, and a three-dimensional data set was assembled from individual photosystem I nanocrystals (~200?nm to 2??m in size). We mitigate the problem of radiation damage in crystallography by using pulses briefer than the timescale of most damage processes. This offers a new approach to structure determination of macromolecules that do not yield crystals of sufficient size for studies using conventional radiation sources or are particularly sensitive to radiation damage.

  15. Catalog of supersoft X-ray sources

    E-Print Network [OSTI]

    J. Greiner

    2000-05-11T23:59:59.000Z

    This catalog comprises an up-to-date (December 1999) list of luminous (>10^36 erg/s), binary supersoft X-ray sources. This electronic version (including the accompannying Web-pages) supersedes the printed version of Greiner (1996).

  16. A High Resolution Intergalactic Explorer for the Soft X-ray/FUV

    E-Print Network [OSTI]

    Martin Elvis; Fabrizio Fiore; the CWE Team

    2003-03-19T23:59:59.000Z

    We present a mission concept for high resolution X-ray spectroscopy with a resolving power, R~6000, (c.f. R=Web'. The Cosmic Web is predicted to contain most of the normal matter (baryons) in the nearby Universe.

  17. Femtosecond Single-Shot Imaging of Nanoscale Ferromagnetic Order in Co/Pd Multilayers using Resonant X-ray Holography

    SciTech Connect (OSTI)

    Wang, Tianhan; Zhu, Diling; Benny Wu,; Graves, Catherine; Schaffert, Stefan; Rander, Torbjorn; Muller, leonard; Vodungbo, Boris; Baumier, Cedric; Bernstein, David P.; Brauer, Bjorn; Cros, Vincent; Jong, Sanne de; Delaunay, Renaud; Fognini, Andreas; Kukreja, Roopali; Lee, Sooheyong; Lopez-Flores, Victor; Mohanty, Jyoti; Pfau, Bastian; Popescu, 5 Horia

    2012-05-15T23:59:59.000Z

    We present the first single-shot images of ferromagnetic, nanoscale spin order taken with femtosecond x-ray pulses. X-ray-induced electron and spin dynamics can be outrun with pulses shorter than 80 fs in the investigated fluence regime, and no permanent aftereffects in the samples are observed below a fluence of 25 mJ/cm{sup 2}. Employing resonant spatially-muliplexed x-ray holography results in a low imaging threshold of 5 mJ/cm{sup 2}. Our results open new ways to combine ultrafast laser spectroscopy with sequential snapshot imaging on a single sample, generating a movie of excited state dynamics.

  18. Three-dimensional mapping of nickel oxidation states using full field x-ray absorption near edge structure nanotomography

    SciTech Connect (OSTI)

    Nelson, George J.; Harris, William M.; Izzo, John R. Jr.; Grew, Kyle N.; Chiu, Wilson K. S. [HeteroFoaM Center, a DOE Energy Frontier Research Center, Department of Mechanical Engineering, University of Connecticut, 191 Auditorium Rd., Storrs, Connecticut 06269-3139 (United States); Chu, Yong S. [National Synchrotron Light Source II, Brookhaven National Laboratory, Bldg. 703 Upton, New York 11973-5000 (United States); Yi, Jaemock [Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Ave., Bldg. 438-B007 Argonne, Illinois 60439 (United States); Andrews, Joy C.; Liu Yijin; Pianetta, Piero [Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., MS 69 Menlo Park, California 94025 (United States)

    2011-04-25T23:59:59.000Z

    The reduction-oxidation cycling of the nickel-based oxides in composite solid oxide fuel cells and battery electrodes is directly related to cell performance. A greater understanding of nickel redox mechanisms at the microstructural level can be achieved in part using transmission x-ray microscopy (TXM) to explore material oxidation states. X-ray nanotomography combined with x-ray absorption near edge structure (XANES) spectroscopy has been applied to study samples containing distinct regions of nickel and nickel oxide (NiO) compositions. Digitally processed images obtained using TXM demonstrate the three-dimensional chemical mapping and microstructural distribution capabilities of full-field XANES nanotomography.

  19. The X-Ray Environment During the Epoch of Terrestrial Planet Formation: Chandra Observations of h Persei

    E-Print Network [OSTI]

    Thayne Currie; Nancy Remage Evans; Brad Spitzbart; Jonathan Irwin; Scott J. Wolk; Jesus Hernandez; Scott J. Kenyon; Jay Pasachoff

    2008-11-11T23:59:59.000Z

    We describe Chandra/ACIS-I observations of the massive ~ 13--14 Myr-old cluster, h Persei, part of the famous Double Cluster (h and chi Persei) in Perseus. Combining the list of Chandra-detected sources with new optical/IR photometry and optical spectroscopy reveals ~ 165 X-ray bright stars with V 1.5 Msun) fall out of X-ray saturation by ~ 10--15 Myr. Changes in stellar structure for > 1.5 Msun stars likely play an important role in this decline of X-ray emission.

  20. Rise time measurement for ultrafast X-ray pulses

    DOE Patents [OSTI]

    Celliers, Peter M. (Berkeley, CA); Weber, Franz A. (Oakland, CA); Moon, Stephen J. (Tracy, CA)

    2005-04-05T23:59:59.000Z

    A pump-probe scheme measures the rise time of ultrafast x-ray pulses. Conventional high speed x-ray diagnostics (x-ray streak cameras, PIN diodes, diamond PCD devices) do not provide sufficient time resolution to resolve rise times of x-ray pulses on the order of 50 fs or less as they are being produced by modern fast x-ray sources. Here, we are describing a pump-probe technique that can be employed to measure events where detector resolution is insufficient to resolve the event. The scheme utilizes a diamond plate as an x-ray transducer and a p-polarized probe beam.

  1. Rise Time Measurement for Ultrafast X-Ray Pulses

    DOE Patents [OSTI]

    Celliers, Peter M.; Weber, Franz A.; Moon, Stephen J.

    2005-04-05T23:59:59.000Z

    A pump-probe scheme measures the rise time of ultrafast x-ray pulses. Conventional high speed x-ray diagnostics (x-ray streak cameras, PIN diodes, diamond PCD devices) do not provide sufficient time resolution to resolve rise times of x-ray pulses on the order of 50 fs or less as they are being produced by modern fast x-ray sources. Here, we are describing a pump-probe technique that can be employed to measure events where detector resolution is insufficient to resolve the event. The scheme utilizes a diamond plate as an x-ray transducer and a p-polarized probe beam.

  2. X-ray microscopy using grazing-incidence reflections optics

    SciTech Connect (OSTI)

    Price, R.H.

    1983-06-30T23:59:59.000Z

    The role of Kirkpatrick-Baez microscopes as the workhorse of the x-ray imaging devices is discussed. This role is being extended with the development of a 22X magnification Kirkpatrick-Baez x-ray microscope with multilayer x-ray mirrors. These mirrors can operate at large angles, high x-ray energies, and have a narrow, well defined x-ray energy bandpass. This will make them useful for numerous experiments. However, where a large solid angle is needed, the Woelter microscope will still be necessary and the technology needed to build them will be useful for many other types of x-ray optics.

  3. X-ray microscopy using grazing-incidence reflection optics

    SciTech Connect (OSTI)

    Price, R.H.

    1981-08-06T23:59:59.000Z

    The Kirkpatrick-Baez microscopes are described along with their role as the workhorse of the x-ray imaging devices. This role is being extended with the development of a 22X magnification Kirkpatrick-Baez x-ray microscope with multilayer x-ray mirrors. These mirrors can operate at large angles, high x-ray energies, and have a narrow, well defined x-ray energy bandpass. This will make them useful for numerous experiments. However, where a large solid angle is needed, the Woelter microscope will still be necessary and the technology needed to build them will be useful for many other types of x-ray optics.

  4. X-ray imaging crystal spectrometer for extended X-ray sources

    DOE Patents [OSTI]

    Bitter, Manfred L. (Princeton, NJ); Fraenkel, Ben (Jerusalem, IL); Gorman, James L. (Bordentown, NJ); Hill, Kenneth W. (Lawrenceville, NJ); Roquemore, A. Lane (Cranbury, NJ); Stodiek, Wolfgang (Princeton, NJ); von Goeler, Schweickhard E. (Princeton, NJ)

    2001-01-01T23:59:59.000Z

    Spherically or toroidally curved, double focusing crystals are used in a spectrometer for X-ray diagnostics of an extended X-ray source such as a hot plasma produced in a tokomak fusion experiment to provide spatially and temporally resolved data on plasma parameters using the imaging properties for Bragg angles near 45. For a Bragg angle of 45.degree., the spherical crystal focuses a bundle of near parallel X-rays (the cross section of which is determined by the cross section of the crystal) from the plasma to a point on a detector, with parallel rays inclined to the main plain of diffraction focused to different points on the detector. Thus, it is possible to radially image the plasma X-ray emission in different wavelengths simultaneously with a single crystal.

  5. X-RAY POINT-SOURCE POPULATIONS CONSTITUTING THE GALACTIC RIDGE X-RAY EMISSION

    SciTech Connect (OSTI)

    Morihana, Kumiko [Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)] [Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Tsujimoto, Masahiro; Ebisawa, Ken [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, 3-1-1 Yoshino-dai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)] [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, 3-1-1 Yoshino-dai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Yoshida, Tessei, E-mail: morihana@crab.riken.jp [National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo 181-8588 (Japan)] [National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2013-03-20T23:59:59.000Z

    Apparently diffuse X-ray emission has been known to exist along the central quarter of the Galactic Plane since the beginning of X-ray astronomy; this is referred to as the Galactic Ridge X-ray emission (GRXE). Recent deep X-ray observations have shown that numerous X-ray point sources account for a large fraction of the GRXE in the hard band (2-8 keV). However, the nature of these sources is poorly understood. Using the deepest X-ray observations made in the Chandra bulge field, we present the result of a coherent photometric and spectroscopic analysis of individual X-ray point sources for the purpose of constraining their nature and deriving their fractional contributions to the hard-band continuum and Fe K line emission of the GRXE. Based on the X-ray color-color diagram, we divided the point sources into three groups: A (hard), B (soft and broad spectrum), and C (soft and peaked spectrum). The group A sources are further decomposed spectrally into thermal and non-thermal sources with different fractions in different flux ranges. From their X-ray properties, we speculate that the group A non-thermal sources are mostly active galactic nuclei and the thermal sources are mostly white dwarf (WD) binaries such as magnetic and non-magnetic cataclysmic variables (CVs), pre-CVs, and symbiotic stars, whereas the group B and C sources are X-ray active stars in flares and quiescence, respectively. In the log N-log S curve of the 2-8 keV band, the group A non-thermal sources are dominant above Almost-Equal-To 10{sup -14} erg cm{sup -2} s{sup -1}, which is gradually taken over by Galactic sources in the fainter flux ranges. The Fe K{alpha} emission is mostly from the group A thermal (WD binaries) and the group B (X-ray active stars) sources.

  6. Fundamental Parameters of Low Mass X-ray Binaries II: X-Ray Persistent Systems

    E-Print Network [OSTI]

    Jorge Casares; Phil Charles

    2005-06-24T23:59:59.000Z

    The determination of fundamental parameters in X-ray luminous (persistent) X-ray binaries has been classically hampered by the large optical luminosity of the accretion disc. New methods, based on irradiation of the donor star and burst oscillations, provide the opportunity to derive dynamical information and mass constraints in many persistent systems for the first time. These techniques are here reviewed and the latest results presented.

  7. X-ray and synchrotron studies of porous silicon

    SciTech Connect (OSTI)

    Sivkov, V. N., E-mail: svn@dm.komisc.ru [Russian Academy of Sciences, Komi Scientific Center, Ural Branch (Russian Federation); Lomov, A. A. [Russian Academy of Sciences, Physical-Technological Institute (Russian Federation)] [Russian Academy of Sciences, Physical-Technological Institute (Russian Federation); Vasil'ev, A. L. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)] [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Nekipelov, S. V. [Komi State Pedagogical Institute (Russian Federation)] [Komi State Pedagogical Institute (Russian Federation); Petrova, O. V. [Russian Academy of Sciences, Komi Scientific Center, Ural Branch (Russian Federation)] [Russian Academy of Sciences, Komi Scientific Center, Ural Branch (Russian Federation)

    2013-08-15T23:59:59.000Z

    The results of comprehensive studies of layers of porous silicon of different conductivity types, grown by anodizing standard Si(111) substrates in an electrolyte based on fluoric acid and ethanol with the addition of 5% of iodine and kept in air for a long time, are discussed. Measurements are performed by scanning electron microscopy, high-resolution X-ray diffraction, and ultrasoft X-ray spectroscopy using synchrotron radiation. The structural parameters of the layers (thickness, strain, and porosity) and atomic and chemical composition of the porous-silicon surface are determined. It is found that an oxide layer 1.5-2.3-nm thick is formed on the surface of the silicon skeleton. The near-edge fine structure of the Si 2p absorption spectrum of this layer corresponds to the fine structure of the 2p spectrum of well coordinated SiO{sub 2}. In this case, the fine structure in the Si 2p-edge absorption region of the silicon skeleton is identical to that of the 2p absorption spectrum of crystalline silicon.

  8. Soft x-ray capabilities for investigating the strongly correlated...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    X-ray, aiming to understand their sciences for applying a new material. In particular, soft x-ray capabilities have been used to obtain microscopic-level understanding of the...

  9. Dawn of x-ray nonlinear optics | Stanford Synchrotron Radiation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Dawn of x-ray nonlinear optics Wednesday, July 8, 2015 - 3:00pm SLAC, Redtail Hawk Conference Room 108A Speaker: David Reis, PULSE Program Description X-ray free electron lasers...

  10. ALS X-Rays Shine a New Light on Catalysis

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    times science has used high-brilliance x-rays to look so closely at these reactions. Lead author Dr. David Mueller at the ALS using x-rays to characterize working fuel cells....

  11. A World's Top-10 X-ray Crystal Structure

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A World's Top-10 X-ray Crystal Structure October 7, 2014 Bookmark and Share Philip Coppens An x-ray crystal structure solved by Philip Coppens has been chosen as one of the world's...

  12. Nanofabrication of Diffractive X-ray Optics for Synchrotrons...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the soft x-ray range and down to 15 nm in the multi keV range. For use at x-ray free-electron laser (XFEL) sources, diffractive optics must be capable of withstanding extreme...

  13. Soft x-ray generation in gases with an ultrashort pulse laser

    SciTech Connect (OSTI)

    Ditmire, T.R.

    1996-01-08T23:59:59.000Z

    An experimental investigation of soft x-ray production resulting from the interaction of intense near infra-red laser radiation with gases is presented in this thesis. Specifically, soft x-ray generation through high order harmonic generation or exploiting intense inverse bremsstrahlung heating is examined. Most of these studies are conducted with femtosecond, terawatt class Cr:LiSrAlF{sub 6} (LiSAF) laser, though results derived from studies with other laser systems are presented as well. The majority of this work is devoted to experimental investigations, however, theoretical and computational models are developed to interpret the data. These studies are motivated by the possibility of utilizing the physics of intense laser/matter interactions as a potential compact source of bright x-rays. Consequently, the thrust of many of the experiments conducted is aimed at characterizing the x-rays produced for possible use in applications. In general, the studies of this manuscript fall into three categories. First, a unique 130 fs, 8 TW laser that is based on chirped pulse amplification, is described, and its performance is evaluated. The generation of x-rays through high order harmonics is then discussed with emphasis on characterizing and optimizing harmonic generation. Finally, the generation of strong, incoherent x-ray radiation by the intense irradiation of large (>1,000 atom) clusters in gas jets, is explored. The physics of laser energy absorption by clusters illuminated with intensities of 10{sup 15} to 10{sup 17} W/cm{sup 2} is considered in detail. X-ray spectroscopy of the hot plasmas that result from the irradiation of the clusters is conducted, and energy transport and kinetics issues in these plasmas are discussed.

  14. The X-ray synchrotron emission of RCW 86 and the implications for its age

    E-Print Network [OSTI]

    Jacco Vink; Johan Bleeker; Kurt van der Heyden; Andrei Bykov; Aya Bamba; Ryo Yamazaki

    2006-07-13T23:59:59.000Z

    We report here X-ray imaging spectroscopy observations of the northeastern shell of the supernova remnant RCW 86 with Chandra and XMM-Newton. Along this part of the shell the dominant X-ray radiation mechanism changes from thermal to synchrotron emission. We argue that both the presence of X-ray synchrotron radiation and the width of the synchrotron emitting region suggest a locally higher shock velocity of V_s = 2700 km/s and a magnetic field of B = 24+/-5 microGauss. Moreover, we also show that a simple power law cosmic ray electron spectrum with an exponential cut-off cannot explain the broad band synchrotron emission. Instead a concave electron spectrum is needed, as predicted by non-linear shock acceleration models. Finally, we show that the derived shock velocity strengthens the case that RCW 86 is the remnant of SN 185.

  15. Method and apparatus for analog signal conditioner for high speed, digital x-ray spectrometer

    DOE Patents [OSTI]

    Warburton, William K. (1300 Mills St., Menlo Park, CA 94025); Hubbard, Bradley (Santa Cruz, CA)

    1999-01-01T23:59:59.000Z

    A signal processing system which accepts input from an x-ray detector-preamplifier and produces a signal of reduced dynamic range for subsequent analog-to-digital conversion. The system conditions the input signal to reduce the number of bits required in the analog-to-digital converter by removing that part of the input signal which varies only slowly in time and retaining the amplitude of the pulses which carry information about the x-rays absorbed by the detector. The parameters controlling the signal conditioner's operation can be readily supplied in digital form, allowing it to be integrated into a feedback loop as part of a larger digital x-ray spectroscopy system.

  16. Time-resolved soft x-ray spectra from laser-produced Cu plasma

    SciTech Connect (OSTI)

    Cone, K V; Dunn, J; Baldis, H A; May, M J; Purvis, M A; Scott, H A; Schneider, M B

    2012-05-02T23:59:59.000Z

    The volumetric heating of a thin copper target has been studied with time resolved x-ray spectroscopy. The copper target was heated from a plasma produced using the Lawrence Livermore National Laboratory's Compact Multipulse Terrawatt (COMET) laser. A variable spaced grating spectrometer coupled to an x-ray streak camera measured soft x-ray emission (800-1550 eV) from the back of the copper target to characterize the bulk heating of the target. Radiation hydrodynamic simulations were modeled in 2-dimensions using the HYDRA code. The target conditions calculated by HYDRA were post-processed with the atomic kinetics code CRETIN to generate synthetic emission spectra. A comparison between the experimental and simulated spectra indicates the presence of specific ionization states of copper and the corresponding electron temperatures and ion densities throughout the laser-heated copper target.

  17. Beyond Chandra - the X-ray Surveyor

    E-Print Network [OSTI]

    Weisskopf, Martin C; Tananbaum, Harvey; Vikhlinin, Alexey

    2015-01-01T23:59:59.000Z

    Over the past 16 years, NASA's Chandra X-ray Observatory has provided an unparalleled means for exploring the universe with its half-arcsecond angular resolution. Chandra studies have deepened our understanding of galaxy clusters, active galactic nuclei, galaxies, supernova remnants, planets, and solar system objects addressing almost all areas of current interest in astronomy and astrophysics. As we look beyond Chandra, it is clear that comparable or even better angular resolution with greatly increased photon throughput is essential to address even more demanding science questions, such as the formation and subsequent growth of black hole seeds at very high redshift; the emergence of the first galaxy groups; and details of feedback over a large range of scales from galaxies to galaxy clusters. Recently, NASA Marshall Space Flight Center, together with the Smithsonian Astrophysical Observatory, has initiated a concept study for such a mission named the X-ray Surveyor. This study starts with a baseline payloa...

  18. X-ray radiography for container inspection

    DOE Patents [OSTI]

    Katz, Jonathan I. (Clayton, MO); Morris, Christopher L. (Los Alamos, NM)

    2011-06-07T23:59:59.000Z

    Arrangements of X-ray inspection systems are described for inspecting high-z materials in voluminous objects such as containers. Inspection methods may involve generating a radiographic image based on detected attenuation corresponding to a pulsed beams of radiation transmitted through a voluminous object. The pulsed beams of radiation are generated by a high-energy source and transmitted substantially downward along an incident angle, of approximately 1.degree. to 30.degree., to a vertical axis extending through the voluminous object. The generated radiographic image may be analyzed to detect on localized high attenuation representative of high-z materials and to discriminate high-z materials from lower and intermediate-z materials on the basis of the high density and greater attenuation of high-z material for higher energy (3-10 MeV) X-rays, and the compact nature of threatening masses of fissionable materials.

  19. X-ray mammography with synchrotron radiation

    SciTech Connect (OSTI)

    Burattini, E. (CNR and INFN-Laboratori Nazionali di Frascati, Frascati, Rome (Italy)); Gambaccini, M.; Marziani, M.; Rimondi, O. (Dipartimento di Fisica dell'Universita and Sezione INFN di Ferrara, Ferrara (Italy)); Indovina, P.L. (Dipartimento di Scienze Fisiche dell'Universita and Sezione INFN di Napoli, Naples (Italy)); Pocek, M.; Simonetti, G. (Istituto di Radiologia, Ospedale Sant'Eugenio, Universita di Tor Vergata, Rome (Italy)); Benassi, M.; Tirelli, C. (Istituto Nazionale del Cancro, Regina Elena, Rome (Italy)); Passariello, R. (Cattedra di Radiologia, Universita dell'Aquila, L'Aquila (Italy))

    1992-01-01T23:59:59.000Z

    For the first time in the literature, radiographs of breast phantoms were obtained using several monochromatic synchrotron radiation x-ray beams of selected energy in the range from 14 to 26 keV. In addition, after optimization of the photon energy as a function of the phantom thickness, several mammographs were obtained on surgically removed human breast specimens containing cancer nodules. Comparison between radiographs using a conventional x-ray unit and those obtained of the same specimens utilizing synchrotron monochromatic beams clearly shows that higher contrast and better resolution can be achieved with synchrotron radiation. These results demonstrate the possibility of obtaining radiographs of excised human breast tissue containing a greater amount of radiological information using synchrotron radiation.

  20. X-rays from Supernova Remnants

    E-Print Network [OSTI]

    B. Aschenbach

    2002-08-28T23:59:59.000Z

    A summary of X-ray observations of supernova remnants is presented including the explosion fragment A of the Vela SNR, Tycho, N132D, RX J0852-4622, the Crab Nebula and the 'bulls eye', and SN 1987A, high-lighting the progress made with Chandra and XMM-Newton and touching upon the questions which arise from these observations and which might inspire future research.

  1. ASCA Observations of the Sgr B2 Cloud: An X-Ray Reflection Nebula

    E-Print Network [OSTI]

    H. Murakami; K. Koyama; M. Sakano; M. Tsujimoto; Y. Maeda

    1999-08-20T23:59:59.000Z

    We present the ASCA results of imaging spectroscopy of the giant molecular cloud Sgr B2. The X-ray spectrum is found to be very peculiar; it exhibits a strong emission line at 6.4 keV, a low energy cutoff below about 4 keV and a pronounced edge-structure at 7.1 keV. The X-ray image is extended and its peak position is shifted from the core of the molecular cloud toward the Galactic center by about 1--2 arcminute. The X-ray spectrum and the morphology are well reproduced by a scenario that X-rays from an external source located in the Galactic center direction are scattered by the molecular cloud Sgr B2, and come into our line of sight. Thus Sgr B2 may be called an X-ray reflection nebula. Possible implications of the Galactic center activity related to this unique source are presented.

  2. Bright X-ray galaxies in SDSS filaments

    E-Print Network [OSTI]

    Tugay, A V

    2013-01-01T23:59:59.000Z

    Eighteen bright X-ray emitting galaxies were found in nearby filaments within SDSS region. Basic X-ray spectral parameters were estimated for these galaxies using power law model with photoelectric absorption. A close pair of X-ray galaxies was found.

  3. Small Angle X-ray Scattering (SAXS) Laboratory Learning Experiences

    E-Print Network [OSTI]

    Meagher, Mary

    .A. & Svergun D.I. (1987). Structure Analysis by Small-Angle X-Ray and Neutron Scattering. NY: Plenum PressSmall Angle X-ray Scattering (SAXS) Laboratory Learning Experiences o - Use of small angle X-ray scattering instrumentation o - Programs that you will use SAXS (BRUKER AXS) PRIMUS (Konarev, Volkov, Koch

  4. Femtosecond laser-electron x-ray source

    DOE Patents [OSTI]

    Hartemann, Frederic V.; Baldis, Hector A.; Barty, Chris P.; Gibson, David J.; Rupp, Bernhard

    2004-04-20T23:59:59.000Z

    A femtosecond laser-electron X-ray source. A high-brightness relativistic electron injector produces an electron beam pulse train. A system accelerates the electron beam pulse train. The femtosecond laser-electron X-ray source includes a high intra-cavity power, mode-locked laser and an x-ray optics system.

  5. Laser photoelectron spectroscopy of ions

    SciTech Connect (OSTI)

    Ellison, G.B. [Univ. of Colorado, Boulder (United States)

    1993-12-01T23:59:59.000Z

    During the last year the author has (a) completed a review article that critically contrasts three methods to measure R-H bond energies, (b) finished a spectroscopic study of the phenylnitrene anion, and (c) successfully completed an overhaul of the light source of the photodetachment spectrometer. The new light source is based on an Ar III laser that provides approximately 100 W of 3.531 eV photons.

  6. Low Temperature Photoelectron Spectroscopy | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Probing the electronic stablility of multiply charged anions:sulfonated pyrene tri- and tetraanions. The strong intramolecular Coulomb repulsion in multiply charged...

  7. X-Ray Interactions with Matter from the Center for X-Ray Optics (CXRO)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Henke, B.L.; Gullikson, E.M.; Davis, J.C.

    The primary interactions of low-energy x-rays within condensed matter, viz. photoabsorption and coherent scattering, are described for photon energies outside the absorption threshold regions by using atomic scattering factors. The atomic scattering factors may be accurately determined from the atomic photoabsorption cross sections using modified Kramers-Kronig dispersion relations. From a synthesis of the currently available experimental data and recent theoretical calculations for photoabsorption, the angle-independent, forward-scattering components of the atomic scattering factors have been thus semiempirically determined and tabulated here for 92 elements and for the region 50-30,000 eV. Atomic scattering factors for all angles of coherent scattering and at the higher photon energies are obtained from these tabulated forward-scattering values by adding a simple angle-dependent form-factor correction. The incoherent scattering contributions that become significant for the light elements at the higher photon energies are similarly determined. The basic x-ray interaction relations that are used in applied x-ray physics are presented here in terms of the atomic scattering factors. The bulk optical constants are also related to the atomic scattering factors. These atomic and optical relations are applied to the detailed calculation of the reflectivity characteristics of a series of practical x-ray mirror, multilayer, and crystal monochromators. Comparisons of the results of this semiempirical,"atom-like", description of x-ray interactions for the low-energy region with those of experiment and ab initio theory are presented.

  8. Proceedings of the workshop on X-ray computed microtomography

    SciTech Connect (OSTI)

    NONE

    1998-02-01T23:59:59.000Z

    This report consists of vugraphs from the nine presentations at the conference. Titles of the presentations are: CMT: Applications and Techniques; Computer Microtomography Using X-rays from Third Generation Synchrotron X-ray; Approaches to Soft-X-ray Nanotomography; Diffraction Enhanced Tomography; X-ray Computed Microtomography Applications at the NSLS; XCMT Applications in Forestry and Forest Products; 3DMA: Investigating Three Dimensional Pore Geometry from High Resolution Images; X-ray Computed Microtomography Studies of Volcanic Rock; and 3-D Visualization of Tomographic Volumes.

  9. Calibrating X-ray Imaging Devices for Accurate Intensity Measurement

    SciTech Connect (OSTI)

    Haugh, M. J.

    2011-07-28T23:59:59.000Z

    The purpose of the project presented is to develop methods to accurately calibrate X-ray imaging devices. The approach was to develop X-ray source systems suitable for this endeavor and to develop methods to calibrate solid state detectors to measure source intensity. NSTec X-ray sources used for the absolute calibration of cameras are described, as well as the method of calibrating the source by calibrating the detectors. The work resulted in calibration measurements for several types of X-ray cameras. X-ray camera calibration measured efficiency and efficiency variation over the CCD. Camera types calibrated include: CCD, CID, back thinned (back illuminated), front illuminated.

  10. Apparatus for monitoring X-ray beam alignment

    DOE Patents [OSTI]

    Steinmeyer, P.A.

    1991-10-08T23:59:59.000Z

    A self-contained, hand-held apparatus is provided for monitoring alignment of an X-ray beam in an instrument employing an X-ray source. The apparatus includes a transducer assembly containing a photoresistor for providing a range of electrical signals responsive to a range of X-ray beam intensities from the X-ray beam being aligned. A circuit, powered by a 7.5 VDC power supply and containing an audio frequency pulse generator whose frequency varies with the resistance of the photoresistor, is provided for generating a range of audible sounds. A portion of the audible range corresponds to low X-ray beam intensity. Another portion of the audible range corresponds to high X-ray beam intensity. The transducer assembly may include an a photoresistor, a thin layer of X-ray fluorescent material, and a filter layer transparent to X-rays but opaque to visible light. X-rays from the beam undergoing alignment penetrate the filter layer and excite the layer of fluorescent material. The light emitted from the fluorescent material alters the resistance of the photoresistor which is in the electrical circuit including the audio pulse generator and a speaker. In employing the apparatus, the X-ray beam is aligned to a complete alignment by adjusting the X-ray beam to produce an audible sound of the maximum frequency. 2 figures.

  11. X-ray server : an outline resource for simulations of x-ray diffraction and scattering.

    SciTech Connect (OSTI)

    Stepanov, S.; Biosciences Division

    2004-01-01T23:59:59.000Z

    X-ray Server is a public project operational at the APS since 1997 with the goals to explore novel network technologies for providing wide scientific community with access to personal research results, establishing scientific collaborations, and refining scientific software. The Server provides Web-based access to a number of programs developed by the author in the field of X-ray diffraction and scattering. The software code operates directly on the Server available for use without downloading. Currently seven programs are accessible that have been used more than 85,000 times. This report discusses the Server philosophy, provides an overview of the physical models and algorithms beneath the codes and demonstrates some applications of the programs. It is shown with examples and statistics how the Server goals are achieved. The plans for further X-ray Server development are outlined.

  12. Coded Aperture Imaging for Fluorescent X-rays-Biomedical Applications

    SciTech Connect (OSTI)

    Haboub, Abdel; MacDowell, Alastair; Marchesini, Stefano; Parkinson, Dilworth

    2013-06-01T23:59:59.000Z

    Employing a coded aperture pattern in front of a charge couple device pixilated detector (CCD) allows for imaging of fluorescent x-rays (6-25KeV) being emitted from samples irradiated with x-rays. Coded apertures encode the angular direction of x-rays and allow for a large Numerical Aperture x- ray imaging system. The algorithm to develop the self-supported coded aperture pattern of the Non Two Holes Touching (NTHT) pattern was developed. The algorithms to reconstruct the x-ray image from the encoded pattern recorded were developed by means of modeling and confirmed by experiments. Samples were irradiated by monochromatic synchrotron x-ray radiation, and fluorescent x-rays from several different test metal samples were imaged through the newly developed coded aperture imaging system. By choice of the exciting energy the different metals were speciated.

  13. HgMn Stars as apparent X-ray emitters

    E-Print Network [OSTI]

    Hubrig, S; Mathys, G

    1998-01-01T23:59:59.000Z

    In the ROSAT all-sky survey 11 HgMn stars were detected as soft X-ray emitters (Berghoefer, Schmitt & Cassinelli 1996). Prior to ROSAT, X-ray observations with the Einstein Observatory had suggested that stars in the spectral range B5-A7 are devoid of X-ray emission. Since there is no X-ray emitting mechanism available for these stars (also not for HgMn stars), the usual argument in the case of an X-ray detected star of this spectral type is the existence of an unseen low-mass companion which is responsible for the X-ray emission. The purpose of the present work is to use all available data for our sample of X-ray detected HgMn stars and conclude on the nature of possible companions.

  14. X-ray emission properties of galaxies in Abell 3128

    E-Print Network [OSTI]

    Russell J. Smith

    2003-07-15T23:59:59.000Z

    We use archival Chandra X-ray Observatory data to investigate X-ray emission from early-type galaxies in the rich z=0.06 cluster Abell 3128. By combining the X-ray count-rates from an input list of optically-selected galaxies, we obtain a statistical detection of X-ray flux, unbiased by X-ray selection limits. Using 87 galaxies with reliable Chandra data, X-ray emission is detected for galaxies down to M_B ~ -19.0, with only an upper limit determined for galaxies at M_B ~ -18.3. The ratio of X-ray to optical luminosities is consistent with recent determinations of the low-mass X-ray binary content of nearby elliptical galaxies. Taken individually, in contrast, we detect significant (3sigma) flux for only six galaxies. Of these, one is a foreground galaxy, while two are optically-faint galaxies with X-ray hardness ratios characteristic of active galactic nuclei. The remaining three detected galaxies are amongst the optically-brightest cluster members, and have softer X-ray spectra. Their X-ray flux is higher than that expected from X-ray binaries, by a factor 2-10; the excess suggests these galaxies have retained their hot gaseous haloes. The source with the highest L_X / L_B ratio is of unusual optical morphology with prominent sharp-edged shells. Notwithstanding these few exceptions, the cluster population overall exhibits X-ray properties consistent with their emission being dominated by X-ray binaries. We conclude that in rich cluster environments, interaction with the ambient intra-cluster medium acts to strip most galaxies of their hot halo gas.

  15. Scanning Transmission X-ray Microscopy: Applications in Atmospheric Aerosol Research

    E-Print Network [OSTI]

    Moffet, Ryan C.

    2011-01-01T23:59:59.000Z

    2-ID-B intermediate-energy scanning X-ray microscope at theW. D. , Morrison, G. R. et al. Scanning transmission X-rayX-ray spectromicroscopy with the scanning transmission X-ray

  16. X-ray generation using carbon nanotubes

    E-Print Network [OSTI]

    Parmee, Richard J.; Collins, Clare M.; Milne, William I.; Cole, Matthew T.

    2015-01-06T23:59:59.000Z

    of these sys- tems are illustrated in Figure 2(b) also outlines the principle mode of operation. Here, sealed in an inexpensive and eas- ily fabricated evacuated glass or ceramic envelope, the elec- trons are liberated from a metallic filament, often made... - ment of CNT-based FE sources is provided in [152]. Here we provide a condensed review of the progress, as it pertains to X-ray sources, since then. CNTs have some of the highest attainable aspect ratios, high thermal conductivity, low chemical...

  17. The BMW X-ray Cluster Survey

    E-Print Network [OSTI]

    Alberto Moretti; Luigi Guzzo; Sergio Campana; Stefano Covino; Davide Lazzati; Marcella Longhetti; Emilio Molinari; Maria Rosa Panzera; Gianpiero Tagliaferri; Ian Dell'Antonio

    2001-03-21T23:59:59.000Z

    We describe the main features of the BMW survey of serendipitous X-ray clusters, based on the still unexploited ROSAT-HRI archival observations. The sky coverage, surface density and first deep optical CCD images of the candidates indicate that this sample can represent an excellent complement to the existing PSPC deep cluster surveys and will provide us with a fully independent probe of the evolution of the cluster abundance, in addition to significantly increasing the number of clusters known at z>0.6.

  18. The BMW X-ray Cluster Survey

    E-Print Network [OSTI]

    Moretti, A; Campana, S; Covino, S; Lazzati, D; Longhetti, M; Molinari, E; Panzera, M R; Tagliaferri, G; Dell'Antonio, I P; Moretti, Alberto; Guzzo, Luigi; Campana, Sergio; Covino, Stefano; Lazzati, Davide; Longhetti, Marcella; Molinari, Emilio; Panzera, Maria Rosa; Tagliaferri, Gianpiero; Antonio, Ian Dell'

    2001-01-01T23:59:59.000Z

    We describe the main features of the BMW survey of serendipitous X-ray clusters, based on the still unexploited ROSAT-HRI archival observations. The sky coverage, surface density and first deep optical CCD images of the candidates indicate that this sample can represent an excellent complement to the existing PSPC deep cluster surveys and will provide us with a fully independent probe of the evolution of the cluster abundance, in addition to significantly increasing the number of clusters known at z>0.6.

  19. Lensless X-Ray Imaging in Reflection

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes |Is Your HomeLatest News ReleasesDepartmentLendingX-Ray Imaging in

  20. Lensless X-Ray Imaging in Reflection

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes |Is Your HomeLatest News ReleasesDepartmentLendingX-Ray Imaging

  1. Lensless X-Ray Imaging in Reflection

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes |Is Your HomeLatest News ReleasesDepartmentLendingX-Ray

  2. Lensless X-Ray Imaging in Reflection

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 -ofLearningLensless ImagingLensless X-Ray

  3. Small Angle X-ray Scattering

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our Instagram Secretary Moniz9Morgan ManagingW.tepidumAngle X-ray Scattering

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

    SciTech Connect (OSTI)

    Len, P M [Univ. of California, Davis, CA (United States). Dept. of Physics

    1997-06-01T23:59:59.000Z

    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.

  5. X-ray emission from Saturn

    E-Print Network [OSTI]

    Ness, J U; Wolk, S J; Dennerl, K; Burwitz, V

    2004-01-01T23:59:59.000Z

    We report the first unambiguous detection of X-ray emission originating from Saturn with a Chandra observation, duration 65.5 ksec with ACIS-S3. Beyond the pure detection we analyze the spatial distribution of X-rays on the planetary surface, the light curve, and some spectral properties. The detection is based on 162 cts extracted from the ACIS-S3 chip within the optical disk of Saturn. We found no evidence for smaller or larger angular extent. The expected background level is 56 cts, i.e., the count rate is (1.6 +- 0.2) 10^-3 cts/s. The extracted photons are rather concentrated towards the equator of the apparent disk, while both polar caps have a relative photon deficit. The inclination angle of Saturn during the observation was -27 degrees, so that the northern hemisphere was not visible during the complete observation. In addition, it was occulted by the ring system. We found a small but significant photon excess at one edge of the ring system. The light curve shows a small dip twice at identical phases,...

  6. The variability properties of X-ray steep and X-ray flat quasars

    E-Print Network [OSTI]

    Fabrizio Fiore; Ari Laor; Martin Elvis; Fabrizio Nicastro; Emanuele Giallongo

    1998-03-20T23:59:59.000Z

    We have studied the variability of 6 low redshift, radio quiet `PG' quasars on three timescales (days, weeks, and months) using the ROSAT HRI. The quasars were chosen to lie at the two extreme ends of the ROSAT PSPC spectral index distribution and hence of the H$\\beta$ FWHM distribution. The observation strategy has been carefully designed to provide even sampling on these three basic timescales and to provide a uniform sampling among the quasars We have found clear evidence that the X-ray steep, narrow H_beta, quasars systematically show larger amplitude variations than the X-ray flat broad H_beta quasars on timescales from 2 days to 20 days. On longer timescales we do not find significant differences between steep and flat quasars, although the statistics are poorer. We suggest that the above correlation between variability properties and spectral steepness can be explained in a scenario in which the X-ray steep, narrow line objects are in a higher L/L_Edd state with respect to the X-ray flat, broad line objects. We evaluated the power spectrum of PG1440+356 (the brigthest quasar in our sample) between 2E-7 and 1E-3 Hz, where it goes into the noise. The power spectrum is roughly consistent with a 1/f law between 1E-3 and 2E-6 Hz. Below this frequency it flattens significantly.

  7. Delayed Ultrafast X-ray Auger Probing (DUXAP) of Nucleobase Ultraviolet Photoprotection

    E-Print Network [OSTI]

    McFarland, B K; Miyabe, S; Tarantelli, F; Aguilar, A; Berrah, N; Bostedt, C; Bozek, J; Bucksbaum, P H; Castagna, J C; Coffee, R; Cryan, J; Fang, L; Feifel, R; Gaffney, K; Glownia, J; Martinez, T; Mucke, M; Murphy, B; Natan, A; Osipov, T; Petrovic, V; Schorb, S; Schultz, Th; Spector, L; Swiggers, M; Tenney, I; Wang, S; White, W; White, J; Gühr, M

    2013-01-01T23:59:59.000Z

    We present a new method for ultrafast spectroscopy of molecular photoexcited dynamics. The technique uses a pair of femtosecond pulses: a photoexcitation pulse initiating excited state dynamics followed by a soft x-ray (SXR) probe pulse that core ionizes certain atoms inside the molecule. We observe the Auger decay of the core hole as a function of delay between the photoexcitation and SXR pulses. The core hole decay is particularly sensitive to the local valence electrons near the core and shows new types of propensity rules, compared to dipole selection rules in SXR absorption or emission spectroscopy. We apply the delayed ultrafast x-ray Auger probing (DUXAP) method to the specific problem of nucleobase photoprotection to demonstrate its potential. The ultraviolet photoexcited \\pi\\pi* states of nucleobases are prone to chemical reactions with neighboring bases. To avoid this, the single molecules funnel the \\pi\\pi* population to lower lying electronic states on an ultrafast timescale under violation of the...

  8. Soft x-ray reduction camera for submicron lithography

    DOE Patents [OSTI]

    Hawryluk, Andrew M. (2708 Rembrandt Pl., Modesto, CA 95356); Seppala, Lynn G. (7911 Mines Rd., Livermore, CA 94550)

    1991-01-01T23:59:59.000Z

    Soft x-ray projection lithography can be performed using x-ray optical components and spherical imaging lenses (mirrors), which form an x-ray reduction camera. The x-ray reduction is capable of projecting a 5x demagnified image of a mask onto a resist coated wafer using 4.5 nm radiation. The diffraction limited resolution of this design is about 135 nm with a depth of field of about 2.8 microns and a field of view of 0.2 cm.sup.2. X-ray reflecting masks (patterned x-ray multilayer mirrors) which are fabricated on thick substrates and can be made relatively distortion free are used, with a laser produced plasma for the source. Higher resolution and/or larger areas are possible by varying the optic figures of the components and source characteristics.

  9. Fabrication process for a gradient index x-ray lens

    DOE Patents [OSTI]

    Bionta, Richard M. (Livermore, CA); Makowiecki, Daniel M. (Livermore, CA); Skulina, Kenneth M. (Livermore, CA)

    1995-01-01T23:59:59.000Z

    A process for fabricating high efficiency x-ray lenses that operate in the 0.5-4.0 keV region suitable for use in biological imaging, surface science, and x-ray lithography of integrated circuits. The gradient index x-ray optics fabrication process broadly involves co-sputtering multi-layers of film on a wire, followed by slicing and mounting on block, and then ion beam thinning to a thickness determined by periodic testing for efficiency. The process enables the fabrication of transmissive gradient index x-ray optics for the 0.5-4.0 keV energy range. This process allows the fabrication of optical elements for the next generation of imaging and x-ray lithography instruments m the soft x-ray region.

  10. Fabrication process for a gradient index x-ray lens

    DOE Patents [OSTI]

    Bionta, R.M.; Makowiecki, D.M.; Skulina, K.M.

    1995-01-17T23:59:59.000Z

    A process is disclosed for fabricating high efficiency x-ray lenses that operate in the 0.5-4.0 keV region suitable for use in biological imaging, surface science, and x-ray lithography of integrated circuits. The gradient index x-ray optics fabrication process broadly involves co-sputtering multi-layers of film on a wire, followed by slicing and mounting on block, and then ion beam thinning to a thickness determined by periodic testing for efficiency. The process enables the fabrication of transmissive gradient index x-ray optics for the 0.5-4.0 keV energy range. This process allows the fabrication of optical elements for the next generation of imaging and x-ray lithography instruments in the soft x-ray region. 13 figures.

  11. Density gradient free electron collisionally excited X-ray laser

    DOE Patents [OSTI]

    Campbell, Edward M. (Pleasanton, CA); Rosen, Mordecai D. (Berkeley, CA)

    1989-01-01T23:59:59.000Z

    An operational X-ray laser (30) is provided that amplifies 3p-3s transition X-ray radiation along an approximately linear path. The X-ray laser (30) is driven by a high power optical laser. The driving line focused optical laser beam (32) illuminates a free-standing thin foil (34) that may be associated with a substrate (36) for improved structural integrity. This illumination produces a generally cylindrically shaped plasma having an essentially uniform electron density and temperature, that exists over a long period of time, and provides the X-ray laser gain medium. The X-ray laser (30) may be driven by more than one optical laser beam (32, 44). The X-ray laser (30) has been successfully demonstrated to function in a series of experimental tests.

  12. Soft x-ray reduction camera for submicron lithography

    DOE Patents [OSTI]

    Hawryluk, A.M.; Seppala, L.G.

    1991-03-26T23:59:59.000Z

    Soft x-ray projection lithography can be performed using x-ray optical components and spherical imaging lenses (mirrors), which form an x-ray reduction camera. The x-ray reduction is capable of projecting a 5x demagnified image of a mask onto a resist coated wafer using 4.5 nm radiation. The diffraction limited resolution of this design is about 135 nm with a depth of field of about 2.8 microns and a field of view of 0.2 cm[sup 2]. X-ray reflecting masks (patterned x-ray multilayer mirrors) which are fabricated on thick substrates and can be made relatively distortion free are used, with a laser produced plasma for the source. Higher resolution and/or larger areas are possible by varying the optic figures of the components and source characteristics. 9 figures.

  13. Density gradient free electron collisionally excited x-ray laser

    DOE Patents [OSTI]

    Campbell, E.M.; Rosen, M.D.

    1984-11-29T23:59:59.000Z

    An operational x-ray laser is provided that amplifies 3p-3s transition x-ray radiation along an approximately linear path. The x-ray laser is driven by a high power optical laser. The driving line focused optical laser beam illuminates a free-standing thin foil that may be associated with a substrate for improved structural integrity. This illumination produces a generally cylindrically shaped plasma having an essentially uniform electron density and temperature, that exists over a long period of time, and provides the x-ray laser gain medium. The x-ray laser may be driven by more than one optical laser beam. The x-ray laser has been successfully demonstrated to function in a series of experimental tests.

  14. Hydrogen deficient donors in low-mass X-ray binaries

    E-Print Network [OSTI]

    Gijs Nelemans

    2007-11-05T23:59:59.000Z

    A number of X-ray binaries (neutron stars or black holes accreting from a companion star) have such short orbital periods that ordinary, hydrogen rich, stars do not fit in. Instead the mass-losing star must be a compact, evolved star, leading to the transfer of hydrogen deficient material to the neutron star. I discuss the current knowledge of these objects, with focus on optical spectroscopy.

  15. Ultra-short wavelength x-ray system

    DOE Patents [OSTI]

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

    2008-01-22T23:59:59.000Z

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

  16. Legacy of the X-Ray Laser Program

    SciTech Connect (OSTI)

    Nilsen, J.

    1993-08-06T23:59:59.000Z

    The X-Ray Laser Program has evolved from a design effort focusing on developing a Strategic Defense Initiative weapon that protects against Soviet ICBMs to a scientific project that is producing new technologies for industrial and medical research. While the great technical successes and failures of the X-ray laser itself cannot be discussed, this article presents the many significant achievements made as part of the X-ray laser effort that are now being used for other applications at LLNL.

  17. Sum rules for polarization-dependent x-ray absorption

    SciTech Connect (OSTI)

    Ankudinov, A.; Rehr, J.J. (Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States))

    1995-01-01T23:59:59.000Z

    A complete set of sum rules is obtained for polarization-dependent x-ray-absorption fine structure and x-ray circular magnetic dichroism (CMD), analogous to those for CMD derived by Thole [ital et] [ital al]. These sum rules relate x-ray-absorption coefficients to the ground-state expectation values of various operators. Problems with applying these sum rules are discussed.

  18. Swift J2218.4+1925: a new hard X-ray selected Polar observed with XMM-Newton

    E-Print Network [OSTI]

    Bernardini, Federico; Mukai, Koji; Falanga, Maurizio

    2014-01-01T23:59:59.000Z

    Swift J2218.4+1925, a hard X-ray source detected by Swift BAT, has been proposed as a candidate magnetic cataclysmic variable of the polar type from optical spectroscopy. Using XMM-Newton we perform detailed timing and spectral analysis with simultaneous X-ray ($0.3-10$ keV) and optical B band data. We complement the spectral study with archival hard X-ray (14-70 keV) spectra collected by Swift BAT as well as with optical, near and mid-infrared photometry from $SDSS$, $2MASS$ and $WISE$ archive, respectively. A strong periodic X-ray signal at 2.16 h, consistent with the recently determined spectroscopic orbital period, adds Swift J2218.4+1925 to the small group of hard X-ray polars and locates it at the low edge of the orbital period gap. The X-ray pulse profile shows the typical bright and faint phases seen in polars ($\\sim 70%$ and $\\sim 30%$ of the orbit, respectively). A pronounced dip centred on the bright phase is also detected. It is stronger at lower energies and is mainly produced by photoelectric ab...

  19. 3D Imaging of Nickel Oxidation States using Full Field X-ray Absorption Near Edge Structure Nanotomography

    SciTech Connect (OSTI)

    Nelson, George; Harris, William; Izzo, John; Grew, Kyle N. (Connecticut); (USARL)

    2012-01-20T23:59:59.000Z

    Reduction-oxidation (redox) cycling of the nickel electrocatalyst phase in the solid oxide fuel cell (SOFC) anode can lead to performance degradation and cell failure. A greater understanding of nickel redox mechanisms at the microstructural level is vital to future SOFC development. Transmission x-ray microscopy (TXM) provides several key techniques for exploring oxidation states within SOFC electrode microstructure. Specifically, x-ray nanotomography and x-ray absorption near edge structure (XANES) spectroscopy have been applied to study samples of varying nickel (Ni) and nickel oxide (NiO) compositions. The imaged samples are treated as mock SOFC anodes containing distinct regions of the materials in question. XANES spectra presented for the individual materials provide a basis for the further processing and analysis of mixed samples. Images of composite samples obtained are segmented, and the distinct nickel and nickel oxide phases are uniquely identified using full field XANES spectroscopy. Applications to SOFC analysis are discussed.

  20. A laser triggered vacuum spark x-ray lithography source

    E-Print Network [OSTI]

    Keating, Richard Allen

    1987-01-01T23:59:59.000Z

    ionized state or the physical processes occurring 15 in a high temperature plasma. There are many advantages to the use of the vacuum spark as an x-ray source; the simplicity of the machine is one. The x-ray output is within the range usable for x-ray... spark apparatus ha- been studied here to determine its applicability to x-ray lithography. A capacitor which stored approximately 3 KJ supplied most of the energy for the plasma. A Nd-YAG laser was used to supply electrons and metallic atoms...

  1. X-ray compass for determining device orientation

    DOE Patents [OSTI]

    Da Silva, Luiz B. (Danville, CA); Matthews, Dennis L. (Moss Beach, CA); Fitch, Joseph P. (Livermore, CA); Everett, Matthew J. (Pleasanton, CA); Colston, Billy W. (Livermore, CA); Stone, Gary F. (Livermore, CA)

    1999-01-01T23:59:59.000Z

    An apparatus and method for determining the orientation of a device with respect to an x-ray source. In one embodiment, the present invention is coupled to a medical device in order to determine the rotational orientation of the medical device with respect to the x-ray source. In such an embodiment, the present invention is comprised of a scintillator portion which is adapted to emit photons upon the absorption of x-rays emitted from the x-ray source. An x-ray blocking portion is coupled to the scintillator portion. The x-ray blocking portion is disposed so as to vary the quantity of x-rays which penetrate the scintillator portion based upon the particular rotational orientation of the medical device with respect to the x-ray source. A photon transport mechanism is also coupled to the scintillator portion. The photon transport mechanism is adapted to pass the photons emitted from the scintillator portion to an electronics portion. By analyzing the quantity of the photons, the electronics portion determines the rotational orientation of the medical device with respect to the x-ray source.

  2. X-ray compass for determining device orientation

    DOE Patents [OSTI]

    Da Silva, L.B.; Matthews, D.L.; Fitch, J.P.; Everett, M.J.; Colston, B.W.; Stone, G.F.

    1999-06-15T23:59:59.000Z

    An apparatus and method for determining the orientation of a device with respect to an x-ray source are disclosed. In one embodiment, the present invention is coupled to a medical device in order to determine the rotational orientation of the medical device with respect to the x-ray source. In such an embodiment, the present invention is comprised of a scintillator portion which is adapted to emit photons upon the absorption of x-rays emitted from the x-ray source. An x-ray blocking portion is coupled to the scintillator portion. The x-ray blocking portion is disposed so as to vary the quantity of x-rays which penetrate the scintillator portion based upon the particular rotational orientation of the medical device with respect to the x-ray source. A photon transport mechanism is also coupled to the scintillator portion. The photon transport mechanism is adapted to pass the photons emitted from the scintillator portion to an electronics portion. By analyzing the quantity of the photons, the electronics portion determines the rotational orientation of the medical device with respect to the x-ray source. 25 figs.

  3. Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    axes must be taken into account for accurate interpretation of XMLD data. Magnetism and X Rays The ancient Greeks and also the Chinese knew about strange and rare...

  4. Generation of Coherent X-Ray Radiation Through Modulation Compression

    E-Print Network [OSTI]

    Qiang, Ji

    2011-01-01T23:59:59.000Z

    ultra-short coherent X-ray radiation by controlling the fraction of the beam that can be properly unchirped using a few-cycle laser

  5. The Daguerreotype and the X-ray: A Deep Look

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    - likely will play a crucial role in future scientific breakthroughs. Last week, hers was the first daguerreotype to undergo powerful x-ray analysis in a collaboration...

  6. X-ray Fading and Expansion in the "Miniature Supernova Remnant" of GK Persei

    E-Print Network [OSTI]

    Takei, D; Yamaguchi, H; Slane, P; Uchiyama, Y; Katsuda, S

    2015-01-01T23:59:59.000Z

    We report on a second epoch of Chandra X-ray imaging spectroscopy of the spatially-resolved old nova remnant GK Persei. An ACIS-S3 observation of 97.4 ks was conducted in November 2013 after a lapse of 13.8 years from the last visit in 2000. The X-ray emitting nebula appeared more faint and patchy compared with the first epoch. The flux decline was particularly evident in fainter regions and the mean decline was 30-40 % in the 0.5-1.2 keV energy band. A typical expansion of the brightest part of the remnant was 1.9 arcsec, which corresponds to an expansion rate of 0.14 arcsec yr^{-1}. The soft X-ray spectra extracted from both the 2000 and 2013 data can be explained by a non-equilibrium ionization collisional plasma model convolved with interstellar absorption, though do not allow us to constrain the origin of the flux evolution. The plasma temperature has not significantly evolved since the 2000 epoch and we conclude that the fading of the X-ray emission is due largely to expansion. This implies that recent ...

  7. NSLS (National Synchrotron Light Source) X-19A beamline performance for x-ray absorption measurements

    SciTech Connect (OSTI)

    Yang, C.Y.; Penner-Hahn, J.E.; Stefan, P.M. (Michigan Univ., Ann Arbor, MI (USA). Dept. of Chemistry; Brookhaven National Lab., Upton, NY (USA))

    1989-01-01T23:59:59.000Z

    Characterization of the X-19A beamline at the National Synchrotron Light Source (NSLS) is described. The beamline is designed for high resolution x-ray absorption spectroscopy over a wide energy range. All of the beamline optical components are compatible with ultrahigh vacuum (UHV) operation. This permits measurements to be made in a window-less mode, thereby facilitating lower energy (<4 KeV) studies. To upgrade the beamline performance, several possible improvements in instrumentation and practice are discussed to increase photon statistics with an optimum energy resolution, while decreasing the harmonic contamination and noise level. A special effort has been made to improve the stability and UHV compatibility of the monochromator system. Initial x-ray absorption results demonstrate the capabilities of this beamline for x-ray absorption studies of low Z elements (e.g. S) in highly dilute systems. The future use of this beamline for carrying out various x-ray absorption experiments is presented. 10 refs., 4 figs.

  8. Workshops on Science Enabled by a Coherent, CW, Synchrotron X-ray Source, June 2011

    SciTech Connect (OSTI)

    Brock, Joel

    2012-01-03T23:59:59.000Z

    In June of 2011 we held six two-day workshops called "XDL-2011: Science at the Hard X-ray Diffraction Limit". The six workshops covered (1) Diffraction-based imaging techniques, (2) Biomolecular structure from non-crystalline materials, (3) Ultra-fast science, (4) High-pressure science, (5) Materials research with nano-beams and (6) X-ray photon correlation spectroscopy (XPCS), In each workshop, invited speaker from around the world presented examples of novel experiments that require a CW, diffraction-limited source. During the workshop, each invited speaker provided a one-page description of the experiment and an illustrative graphic. The experiments identified by the workshops demonstrate the broad and deep scientific case for a CW coherent synchrotron x-ray source. The next step is to perform detailed simulations of the best of these ideas to test them quantitatively and to guide detailed x-ray beam-line designs. These designs are the first step toward developing detailed facility designs and cost estimates.

  9. X-Ray Emission Spectrometer Design with Single-Shot Pump-Probe and Resonant Excitation Capabilities

    SciTech Connect (OSTI)

    Spoth, Katherine; /SUNY, Buffalo /SLAC

    2012-08-28T23:59:59.000Z

    Core-level spectroscopy in the soft X-ray regime is a powerful tool for the study of chemical bonding processes. The ultrafast, ultrabright X-ray pulses generated by the Linac Coherent Light Source (LCLS) allow these reactions to be studied in greater detail than ever before. In this study, we investigated a conceptual design of a spectrometer for the LCLS with imaging in the non-dispersive direction. This would allow single-shot collection of X-ray emission spectroscopy (XES) measurements with varying laser pump X-ray probe delay or a variation of incoming X-ray energy over the illuminated area of the sample. Ray-tracing simulations were used to demonstrate how the components of the spectrometer affect its performance, allowing a determination of the optimal final design. These simulations showed that the spectrometer's non-dispersive focusing is extremely sensitive to the size of the sample footprint; the spectrometer is not able to image a footprint width larger than one millimeter with the required resolution. This is compatible with a single shot scheme that maps out the laser pump X-ray probe delay in the non-dispersive direction as well as resonant XES applications at normal incidence. However, the current capabilities of the Soft X-Ray (SXR) beamline at the LCLS do not produce the required energy range in a small enough sample footprint, hindering the single shot resonant XES application at SXR for chemical dynamics studies at surfaces. If an upgraded or future beamline at LCLS is developed with lower monochromator energy dispersion the width can be made small enough at the required energy range to be imaged by this spectrometer design.

  10. SYSTEMATIC UNCERTAINTIES IN THE SPECTROSCOPIC MEASUREMENTS OF NEUTRON-STAR MASSES AND RADII FROM THERMONUCLEAR X-RAY BURSTS. II. EDDINGTON LIMIT

    SciTech Connect (OSTI)

    Guever, Tolga; Oezel, Feryal; Psaltis, Dimitrios [Department of Astronomy, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)

    2012-03-01T23:59:59.000Z

    Time-resolved X-ray spectroscopy of thermonuclear bursts observed from low-mass X-ray binaries offer a unique tool to measure neutron-star masses and radii. In this paper, we continue our systematic analysis of all the X-ray bursts observed with Rossi X-ray Timing Explorer from X-ray binaries. We determine the events that show clear evidence for photospheric radius expansion and measure the Eddington limits for these accreting neutron stars using the bolometric fluxes attained at the touchdown moments of each X-ray burst. We employ a Bayesian technique to investigate the degree to which the Eddington limit for each source remains constant between bursts. We find that for sources with a large number of radius expansion bursts, systematic uncertainties are at a 5%-10% level. Moreover, in six sources with only pairs of Eddington-limited bursts, the distribution of fluxes is consistent with a {approx}10% fractional dispersion. This indicates that the spectroscopic measurements of neutron-star masses and radii using thermonuclear X-ray bursts can reach the level of accuracy required to distinguish between different neutron-star equations of state, provided that uncertainties related to the overall flux calibration of X-ray detectors are of comparable magnitude.

  11. X-ray laser system, x-ray laser and method

    DOE Patents [OSTI]

    London, Richard A. (Oakland, CA); Rosen, Mordecai D. (Berkeley, CA); Strauss, Moshe (Omer, IL)

    1992-01-01T23:59:59.000Z

    Disclosed is an x-ray laser system comprising a laser containing generating means for emitting short wave length radiation, and means external to said laser for energizing said generating means, wherein when the laser is in an operative mode emitting radiation, the radiation has a transverse coherence length to width ratio of from about 0.05 to 1. Also disclosed is a method of adjusting the parameters of the laser to achieve the desired coherence length to laser width ratio.

  12. Constraints on jet X-ray emission in low/hard state X-ray binaries

    E-Print Network [OSTI]

    Thomas J. Maccarone

    2005-03-31T23:59:59.000Z

    We show that the combination of the similarities between the X-ray properties of low luminosity accreting black holes and accreting neutron stars, combined with the differences in their radio properties argues that the X-rays from these systems are unlikely to be formed in the relativistic jets. Specifically, the spectra of extreme island state neutron stars and low/hard state black holes are known to be indistinguishable, while the power spectra from these systems are known to show only minor differences beyond what would be expected from scaling the characteristic variability frequencies by the mass of the compact object. The spectral and temporal similarities thus imply a common emission mechanism that has only minor deviations from having all key parameters scaling linearly with the mass of the compact object, while we show that this is inconsistent with the observations that the radio powers of neutron stars are typically about 30 times lower than those of black holes at the same X-ray luminosity. We also show that an abrupt luminosity change would be expected when a system makes a spectral state transition from a radiatively inefficient jet dominated accretion flow to a thin disk dominated flow, but that such a change is not seen.

  13. Isotropic star in low-mass X-ray binaries and X-ray pulsars

    E-Print Network [OSTI]

    Mehedi Kalam; Sk. Monowar Hossein; Sajahan Molla

    2014-10-01T23:59:59.000Z

    We present a model for compact stars in the low mass X-ray binaries(LMXBs) and X-ray pulsars using a metric given by John J. Matese and Patrick G. Whitman \\citep{Matese and Whitman1980}. Here the field equations are reduced to a system of two algebraic equations considering the isotropic pressure. Compact star candidates 4U 1820-30(radius=10km) in LMXBs, and Her X-1(radius=7.7km), SAX J 1808.4-3658(SS1)(radius=7.07km) and SAX J 1808.4-3658(SS2)(radius=6.35km) in X-ray pulsars satisfy all the energy conditions, TOV-equation and stability condition. From our model, we have derived mass($M$), central density($\\rho_{0}$), suface density($\\rho_{b}$), central pressure($p_{0}$), surface pressure($p_{b}$) and surface red-shift($Z_{s}$) of the above mentioned stars, which are very much consistant with the observed/reported datas\\citep{N. K. Glendenning1997,Gondek2000}. We have also observe the adiabatic index($\\gamma$>4/3) of the above steller objects.

  14. Residual stress measurement using X-ray diffraction 

    E-Print Network [OSTI]

    Anderoglu, Osman

    2005-02-17T23:59:59.000Z

    .3.6.2. Synchrotron Diffraction.........................................................................9 II. FUNDAMENTAL CONCEPTS IN X-RAY DIFFRACTION.....................................12 2.1. X-ray Source... radiations ...................................................................16 Table 2.2 Structure factors and reflection conditions ...................................................20 Table 4.1 Chemical composition of SS316...

  15. Ultrafast x-rays: radiographing magnetism Project overview

    E-Print Network [OSTI]

    Haviland, David

    , head of the ultrafast magnetism group. Stanford PULSE is a worldwide renowned centre for ultrafast1 Ultrafast x-rays: radiographing magnetism Project overview The main purpose of the proposed, it is now possible to achieve x-ray pulses that are a few femtoseconds long and that are focused within

  16. High resolution energy-sensitive digital X-ray

    DOE Patents [OSTI]

    Nygren, David R. (Berkeley, CA)

    1995-01-01T23:59:59.000Z

    An apparatus and method for detecting an x-ray and for determining the depth of penetration of an x-ray into a semiconductor strip detector. In one embodiment, a semiconductor strip detector formed of semiconductor material is disposed in an edge-on orientation towards an x-ray source such that x-rays From the x-ray source are incident upon and substantially perpendicular to the front edge of the semiconductor strip detector. The semiconductor strip detector is formed of a plurality of segments. The segments are coupled together in a collinear arrangement such that the semiconductor strip detector has a length great enough such that substantially all of the x-rays incident on the front edge of the semiconductor strip detector interact with the semiconductor material which forms the semiconductor strip detector. A plurality of electrodes are connected to the semiconductor strip detect or such that each one of the of semiconductor strip detector segments has at least one of the of electrodes coupled thereto. A signal processor is also coupled to each one of the electrodes. The present detector detects an interaction within the semiconductor strip detector, between an x-ray and the semiconductor material, and also indicates the depth of penetration of the x-ray into the semiconductor strip detector at the time of the interaction.

  17. Residual stress measurement using X-ray diffraction

    E-Print Network [OSTI]

    Anderoglu, Osman

    2005-02-17T23:59:59.000Z

    -rays..............................................................................................16 2.4. Bragg's Law ..........................................................................................................18 2.5. Diffractometer Geometry... Figure 2.2 Schematic showing the basic components of a modern x-ray tube. Beryllium window is highly transparent to x-rays...............................15 Figure 2.3 Coherent scattering from an electron to a point P...

  18. Shad-o-Snap X-Ray Camera Hardware Manual

    E-Print Network [OSTI]

    -o-Snap x-ray camera is a complete, stand-alone x-ray imaging device featuring "smart" microprocessor-controlled camera electronics and a convenient USB interface. The plug- and-play interface allows easy control by the silicon photodiodes. The Shad-o-Snap camera also includes electronics to digitize the video signal

  19. Measurement and characterization of x-ray spot size

    SciTech Connect (OSTI)

    Mueller, K.H.

    1989-01-01T23:59:59.000Z

    In planning an x-ray imaging experiment one must have an accurate model of the imaging system to obtain optimum results. The blurring caused by the finite size of the x-ray source is often the least understood element in the system. We have developed experimental and analytical methods permitting accurate measurement and modeling of the x-ray source. The model offers a simple and accurate way to optimize the radiographic geometry for any given experimental requirement (i.e., resolution and dose at detector). Any text on radiography will mention the effects of the finite size of the x-ray source on image quality and how one can minimize this influence by the choice of a small radiographic magnification. The film blur (independent of the source blur) is often treated as a single number and combined with an effective blur dimension for the x-ray source to give a total blur on the film. In this paper, we will develop a treatment of x-ray sources based on the modulation transfer function (MTF). This approach allows us to infer the spatial distribution function of the electron beam that produces the bremsstrahlung x-rays and to predict the performance of an x-ray imaging system if we know the MTF of the detector. This treatment is much more accurate than a single number characterization. 4 refs., 7 figs.

  20. Fourteenth National School on Neutron and X-ray Scattering

    E-Print Network [OSTI]

    Pennycook, Steve

    Fourteenth National School on Neutron and X-ray Scattering August 12 - 25, 2012 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major Ridge National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang

  1. Neutron and X-ray Scattering Study of Magnetic Manganites

    E-Print Network [OSTI]

    Boothroyd, Andrew

    Neutron and X-ray Scattering Study of Magnetic Manganites Graeme Eoin Johnstone A Thesis submitted are performed using a variety of neutron scattering and x-ray scattering techniques. The electronic ground for analysing the results of the polarised neutron scattering experiment. There are a large number of people who

  2. Tenth National School on Neutron and X-ray Scattering

    E-Print Network [OSTI]

    Pennycook, Steve

    Tenth National School on Neutron and X-ray Scattering September 24 - October 11, 2008 at Argonne of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne

  3. National School on Neutron and X-ray Scattering

    E-Print Network [OSTI]

    15th National School on Neutron and X-ray Scattering August 10 - 24, 2013 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major Ridge National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang

  4. Thirteenth National School on Neutron and X-ray Scattering

    E-Print Network [OSTI]

    Thirteenth National School on Neutron and X-ray Scattering June 11 ­ June 25, 2011 at Argonne of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne

  5. Sixteenth National School on Neutron and X-ray Scattering

    E-Print Network [OSTI]

    Pennycook, Steve

    Sixteenth National School on Neutron and X-ray Scattering June 14-28, 2014 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major's Neutron Scattering Science Division. Scientific Directors: Suzanne G.E. te Velthuis, Esen Ercan Alp

  6. Twelfth National School on Neutron and X-ray Scattering

    E-Print Network [OSTI]

    Pennycook, Steve

    Twelfth National School on Neutron and X-ray Scattering June 12 ­ June 26, 2010 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne

  7. National School on Neutron and X-ray Scattering

    E-Print Network [OSTI]

    Pennycook, Steve

    National School on Neutron and X-ray Scattering May 30 ­ June 13, 2009 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne

  8. Electromagnetic Application: X-RAY Alawi H. Ba-Surrah

    E-Print Network [OSTI]

    Masoudi, Husain M.

    , Pulyui published high-quality x-ray images in journals in Paris and London. · Nikola Tesla In April 1887, Nikola Tesla began to investigate X-rays using high voltages and tubes of his own design, as well. The principle behind Tesla's device is called the Bremsstrahlung process, in which a high-energy secondary X

  9. Chandra X-ray Analysis of Galaxy Cluster A168

    E-Print Network [OSTI]

    Yanbin Yang; Zhiying Huo; Xu Zhou; Suijian Xue; Shude Mao; Jun Ma; Jiansheng Chen

    2004-06-29T23:59:59.000Z

    We present Chandra X-ray observations of galaxy cluster A168 (z=0.045). Two X-ray peaks with a projected distance of 676 kpc are found to be located close to two dominant galaxies, respectively. Both peaks are significantly offset from the peak of the number density distribution of galaxies. This suggests that A168 consists of two subclusters, a northern subcluster (A168N) and a southern subcluster (A168S). Further X-ray imaging analysis reveals that (1) the X-ray isophotes surrounding the two X-ray peaks are heavily distorted, (2) an elongated and ontinuous filament connects the two X-ray peaks. These suggest that strong interactions have occurred between the two subclusters. Spectral analysis shows that A168 has a mean temperature of 2.53 +/- 0.09 keV and a mean metallicity of 0.31 +/- 0.04 Z_{solar}. The metallicity is roughly a constant across the cluster but the temperature shows some systematic variations. Most X-ray, optical and radio properties of A168 are consistent with it being an off-axis merger several Gyrs after a core passage, although detailed numerical simulations are required to see whether the observed properties, in particular the significant offset between the optical and X-ray centers, can be reproduced in such a scenario.

  10. Millisecond oscillations during thermonuclear X-ray bursts

    E-Print Network [OSTI]

    Muno, Michael Patrick, 1975-

    2002-01-01T23:59:59.000Z

    I analyze 68 oscillation trains detected in a search of 159 thermonuclear bursts from eight neutron star X-ray binaries observed with the Rossi X-ray Timing Explorer. I use all data that were public as of September 2001. ...

  11. X-ray Absorption Spectroscopy of Biologically Relevant Systems

    E-Print Network [OSTI]

    Uejio, Janel Sunayo

    2010-01-01T23:59:59.000Z

    of the interaction of the carboxylate with lithium; this isinteractions of carboxylate with the monovalent cations lithium,lithium acetate revealing distinct shifts between the cations, indicative of preferential interactions.

  12. X-ray Absorption Spectroscopy: a Powerful Tool for Investigating

    E-Print Network [OSTI]

    Morante, Silvia

    LURE D 2.15 2.6 ESRF Grenoble D 6. 0.6, 1.3 5. GERMANY BESSY I BESSY D 0.8 19.4 DELTA Dortmund 1.5 5.5 BESSY II BESSY D 1.7 5.0 ANKA Karlsruhe D 2.5 2 ELSA Bonn 3.5 1.4 DORIS DESY 5. 0.55 6. INDIA INDUS I

  13. X-ray Absorption Spectroscopy: a Powerful Tool for Investigating

    E-Print Network [OSTI]

    Morante, Silvia

    ) accelerated particles relativistic (E = mc2) radial acceleration (e.g. deflected by a magnet) Lorentz force F Synchrotronstrahlung (BESSY), Berlin 8. Canadian Light Source (CLS), Saskatoon, Saskatchewan 9. Center for Advanced

  14. TENDER ENERGY X-RAY ABSORPTION SPECTROSCOPY (TES)

    E-Print Network [OSTI]

    Ohta, Shigemi

    productivity at the earliest possible date. · Strategy combines in-house and external aspects to create world IMPACT: · Energy Materials: Photovoltaic, fuel-cell, battery and superconducting (nano

  15. Characterization of Gas Shales by X-ray Raman Spectroscopy |...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Drew Pomerantz, Schlumberger Unconventional hydrocarbon resources such as gas shale and oil-bearing shale have emerged recently as economically viable sources of energy,...

  16. XRMS: X-Ray Spectroscopy of Magnetic Solids

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsingWhat isJoin theanniversaryI 1 0ornl.gov XGInXRMS:

  17. X-Ray Diffraction Microscopy of Magnetic Structures

    SciTech Connect (OSTI)

    Turner, J.; Lima, E.; Huang, X.; Krupin, O.; Seu, K.; Parks, D.; Kevan, S.; Kisslinger, K.; McNulty, I.; Gambino, R.; Mangin, S.; Roy, S. and Fischer, P.

    2011-07-14T23:59:59.000Z

    We report the first proof-of-principle experiment of iterative phase retrieval from magnetic x-ray diffraction. By using the resonant x-ray excitation process and coherent x-ray scattering, we show that linearly polarized soft x rays can be used to image both the amplitude and the phase of magnetic domain structures. We recovered the magnetic structure of an amorphous terbium-cobalt thin film with a spatial resolution of about 75 nm at the Co L{sub 3} edge at 778 eV. In comparison with soft x-ray microscopy images recorded with Fresnel zone plate optics at better than 25 nm spatial resolution, we find qualitative agreement in the observed magnetic structure.

  18. X-Ray Observations of Gamma-Ray Burst Afterglows

    E-Print Network [OSTI]

    Filippo Frontera

    2004-06-25T23:59:59.000Z

    The discovery by the BeppoSAX satellite of X-ray afterglow emission from the gamma-ray burst which occurred on 28 February 1997 produced a revolution in our knowledge of the gamma-ray burst phenomenon. Along with the discovery of X-ray afterglows, the optical afterglows of gamma-ray bursts were discovered and the distance issue was settled, at least for long $\\gamma$-ray bursts. The 30 year mystery of the gamma-ray burst phenomenon is now on the way to solution. Here I rewiew the observational status of the X-ray afterglow emission, its mean properties (detection rate, continuum spectra, line features, and light curves), and the X-ray constraints on theoretical models of gamma-ray bursters and their progenitors. I also discuss the early onset afterglow emission, the remaining questions, and the role of future X-ray afterglow observations.

  19. Scattering of x rays from low-Z materials

    SciTech Connect (OSTI)

    Gaines, J.L.; Kissel, L.D.; Catron, H.C.; Hansen, R.A.

    1980-08-01T23:59:59.000Z

    X rays incident on thin beryllium, boron, carbon, and other low-Z materials undergo both elastic and inelastic scattering as well as diffraction from the crystalline or crystalline-like structure of the material. Unpolarized monoenergetic x rays in the 1.5 to 8.0-keV energy range were used to determine the absolute scattering efficiency of thin beryllium, carbon, and boron foils. These measurements are compared to calculated scattering efficiencies predicted by single-atom theories. In addition, the relative scattering efficiency versus x-ray energy was measured for other low-Z foils using unpolarized bremsstrahlung x rays. In all the low-Z foils examined, we observed Bragg-like x-ray diffraction due to the ordered structure of the materials.

  20. Deep x-ray lithography for micromechanics

    SciTech Connect (OSTI)

    Christenson, T.R. [Sandia National Labs., Albuquerque, NM (United States); Guckel, H. [Wisconsin Univ., Madison, WI (United States). Dept. of Electrical and Computer Engineering

    1995-08-01T23:59:59.000Z

    Extensions of the German LIGA process have brought about fabrication capability suitable for cost effective production of precision engineered components. The process attributes allow fabrication of mechanical components which are not capable of being made via conventional subtractive machining methods. Two process improvements have been responsible for this extended capability which involve the areas of thick photoresist application and planarization via precision lapping. Application of low-stress x-ray photoresist has been achieved using room temperature solvent bonding of a preformed photoresist sheet. Precision diamond lapping and polishing has provided a flexible process for the planarization of a wide variety of electroplated metals in the presence of photoresist. Exposure results from the 2.5 GeV National Synchrotron Light Source storage ring at Brookhaven National Laboratory have shown that structural heights of several millimeter and above are possible. The process capabilities are also well suited for microactuator fabrication. Linear and rotational magnetic microactuators have been constructed which use coil winding technology with LIGA fabricated coil forms. Actuator output forces of 1 milliNewton have been obtained with power dissipation on the order of milliWatts. A rotational microdynamometer system which is capable of measuring torque-speed data is also discussed.

  1. X-ray Emission from Massive StarsX-ray Emission from Massive Stars David CohenDavid Cohen

    E-Print Network [OSTI]

    Cohen, David

    X-ray Emission from Massive StarsX-ray Emission from Massive Stars David CohenDavid Cohen/s)Velocity (km/s) #12;absorption emission emission occulted emission emission UV telescope side side front back #12;absorption emission emission occulted emission emission UV telescope side side front back #12;The

  2. AugEX: AUGER ELECTRON AND X-RAY SPECTROMETER ON CHANDRAYAAN-2 ROVER

    E-Print Network [OSTI]

    Bapat, Bhas

    for determining elemental composition which have a space heritage X-Ray Fluorescence (XRF) Particle-induced X-ray fluorescence (XRF) Expected Advantage: cover low Z elements with higher sensitivity than XRF or PIXE. ACHARYA-ray absorption or charged particle bombardment X-ray emission induced by X-ray absorption: XRF X-ray emission

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

    SciTech Connect (OSTI)

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

    2011-07-06T23:59:59.000Z

    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.

  4. X-ray absorption spectroscopic studies of mononuclear non-heme iron enzymes

    SciTech Connect (OSTI)

    Westre, T.E.

    1996-01-01T23:59:59.000Z

    Fe-K-edge X-ray absorption spectroscopy (XAS) has been used to investigate the electronic and geometric structure of the iron active site in non-heme iron enzymes. A new theoretical extended X-ray absorption fine structure (EXAFS) analysis approach, called GNXAS, has been tested on data for iron model complexes to evaluate the utility and reliability of this new technique, especially with respect to the effects of multiple-scattering. In addition, a detailed analysis of the 1s{yields}3d pre-edge feature has been developed as a tool for investigating the oxidation state, spin state, and geometry of iron sites. Edge and EXAFS analyses have then been applied to the study of non-heme iron enzyme active sites.

  5. Development of soft X-ray polarized light beamline on Indus-2 synchrotron radiation source

    SciTech Connect (OSTI)

    Phase, D. M., E-mail: mgupta@csr.res.in; Gupta, Mukul, E-mail: mgupta@csr.res.in; Potdar, S., E-mail: mgupta@csr.res.in; Behera, L., E-mail: mgupta@csr.res.in; Sah, R., E-mail: mgupta@csr.res.in; Gupta, Ajay, E-mail: mgupta@csr.res.in [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore, 452001 (India)

    2014-04-24T23:59:59.000Z

    This article describes the development of a soft x-ray beamline on a bending magnet source of Indus-2 storage ring (2.5 GeV) and some preliminary results of x-ray absorption spectroscopy (XAS) measurements using the same. The beamline layout is based on a spherical grating monochromator. The beamline is able to accept synchrotron radiation from the bending magnet port BL-1 of the Indus-2 ring with a wide solid angle. The large horizontal and vertical angular acceptance contributes to high photon flux and selective polarization respectively. The complete beamline is tested for ultrahigh vacuum (UHV) ? 10{sup ?10} mbar. First absorption spectrum was obtained on HOPG graphite foil. Our performance test indicates that modest resolving power has been achieved with adequate photon flux to carry out various absorption experiments.

  6. Revealing a hard X-ray spectral component reverberating within one light hour of the central Supermassive Black Hole in Ark 564

    E-Print Network [OSTI]

    Giustini, M; Reeves, J N; Miller, L; Legg, E; Kraemer, S B; George, I M

    2015-01-01T23:59:59.000Z

    Ark 564 (z=0.0247) is an X-ray bright NLS1. By using advanced X-ray timing techniques, Legg et al. (2012) discovered an excess of "delayed" emission in the hard X-ray band (4-7.5 keV) following about 1000 seconds after "flaring" light in the soft X-ray band (0.4-1 keV). We report on the X-ray spectral analysis of eight XMM-Newton and one Suzaku observation of Ark 564. High-resolution spectroscopy was performed with the RGS in the soft X-ray band, while broad-band spectroscopy was performed with the EPIC-pn and XIS/PIN instruments. We analysed time-averaged, flux-selected, and time-resolved spectra. Despite the large variability in flux, the broad band spectral shape of Ark 564 is not dramatically varying and can be reproduced either by a superposition of a power law and a blackbody emission, or by a Comptonized power law emission model. High resolution spectroscopy revealed the presence of ionised gas along the line of sight at the systemic redshift of the source, with a low column density and a range of ioni...

  7. Soft X-Ray Spectroscopic Study of Dense Strontium-Doped Lanthanum Manganite Cathodes for Solid Oxide Fuel Cell Applications

    SciTech Connect (OSTI)

    L Piper; A Preston; S Cho; A DeMasi; J Laverock; K Smith; L Miara; J Davis; S Basu; et al.

    2011-12-31T23:59:59.000Z

    The evolution of the Mn charge state, chemical composition, and electronic structure of La{sub 0.8}Sr{sub 0.2}MnO{sub 3} (LSMO) cathodes during the catalytic activation of solid oxide fuel cell (SOFC) has been studies using X-ray spectroscopy of as-processed, exposed, and activated dense thin LSMO films. Comparison of O K-edge and Mn L{sub 3,2}-edge X-ray absorption spectra from the different stages of LSMO cathodes revealed that the largest change after the activation occurred in the Mn charge state with little change in the oxygen environment. Core-level X-ray photoemission spectroscopy and Mn L{sub 3} resonant photoemission spectroscopy studies of exposed and as-processed LSMO determined that the SOFC environment (800 C ambient pressure of O{sub 2}) alone results in La deficiency (severest near the surface with Sr doping >0.55) and a stronger Mn{sup 4+} contribution, leading to the increased insulating character of the cathode prior to activation. Meanwhile, O K-edge X-ray absorption measurements support Sr/La enrichment nearer the surface, along with the formation of mixed Sr{sub x}Mn{sub y}O{sub z} and/or passive MnO{sub x} and SrO species.

  8. The XMM-Newton Survey in the Marano Field I. The X-ray data and optical follow-up

    E-Print Network [OSTI]

    M. Krumpe; G. Lamer; A. D. Schwope; S. Wagner; G. Zamorani; M. Mignoli; R. Staubert; L. Wisotzki; G. Hasinger

    2006-12-14T23:59:59.000Z

    We report on a medium deep XMM-Newton survey of the Marano Field and optical follow-up observations. The mosaicked XMM-Newton pointings in this optical quasar survey field cover 0.6 square degree with a total of 120 ksec good observation time. We detected 328 X-ray sources in total. The turnover flux of our sample is f~5x10^(-15) erg/cm^2/s in the 0.2-10 keV band. With VLT FORS1 and FORS2 spectroscopy we classified 96 new X-ray counterparts. The central 0.28 square degree, where detailed optical follow-up observations were performed, contain 170 X-ray sources (detection likelihood ML>10), out of which 48 had already been detected by ROSAT. In this region we recover 23 out of 29 optically selected quasars. With a total of 110 classifications in our core sample we reach a completeness of ~65%. About one third of the XMM-Newton sources is classified as type II AGN with redshifts mostly below 1.0. Furthermore, we detect five high redshift type II AGN (2.2X-ray colors of the core sample indicate that most of the still unidentified X-ray sources are likely to be type II AGN. We calculate absorbing column densities and show that the ratio of absorbed to unabsorbed objects is significantly higher for type II AGN than for type I AGN. Nevertheless, we find a few unabsorbed type II AGN. The X-ray hardness ratios of some high redshift type I AGN also give an indication of heavy absorption. However, none of these type I objects is bright enough for spectral extraction and detailed model fitting. Furthermore, we classified three X-ray bright optically normal galaxies (XBONGs) as counterparts. They show properties similar to type II AGN, probably harbouring an active nucleus.

  9. Time-resolved soft x-ray absorption setup using multi-bunch operation modes at synchrotrons

    SciTech Connect (OSTI)

    Stebel, L.; Sigalotti, P.; Ressel, B.; Cautero, G. [Sincrotrone Trieste, S.S. 14 km 163.5, Area Science Park, 34149 Basovizza (Italy); Malvestuto, M.; Capogrosso, V. [Sincrotrone Trieste, S.S. 14 km 163.5, Area Science Park, 34149 Basovizza (Italy); Department of Physics, University of Trieste, via A. Valerio 2, 34127, Trieste (Italy); Bondino, F.; Magnano, E. [IOM-CNR, TASC laboratory, S.S. 14 km 163.5, Area Science Park, 34149 Basovizza (Italy); Parmigiani, F. [Sincrotrone Trieste, S.S. 14 km 163.5, Area Science Park, 34149 Basovizza (Italy); Department of Physics, University of Trieste, via A. Valerio 2, 34127, Trieste (Italy); IOM-CNR, TASC laboratory, S.S. 14 km 163.5, Area Science Park, 34149 Basovizza (Italy)

    2011-12-15T23:59:59.000Z

    Here, we report on a novel experimental apparatus for performing time-resolved soft x-ray absorption spectroscopy in the sub-ns time scale using non-hybrid multi-bunch mode synchrotron radiation. The present setup is based on a variable repetition rate Ti:sapphire laser (pump pulse) synchronized with the {approx}500 MHz x-ray synchrotron radiation bunches and on a detection system that discriminates and singles out the significant x-ray photon pulses by means of a custom made photon counting unit. The whole setup has been validated by measuring the time evolution of the L{sub 3} absorption edge during the melting and the solidification of a Ge single crystal irradiated by an intense ultrafast laser pulse. These results pave the way for performing synchrotron time-resolved experiments in the sub-ns time domain with variable repetition rate exploiting the full flux of the synchrotron radiation.

  10. A doubly curved elliptical crystal spectrometer for the study of localized x-ray absorption in hot plasmas

    SciTech Connect (OSTI)

    Cahill, Adam D., E-mail: adc87@cornell.edu; Hoyt, Cad L.; Pikuz, Sergei A.; Shelkovenko, Tania; Hammer, David A. [Cornell University, Electrical and Computer Engineering, Ithaca, NY 14853 (United States)

    2014-10-15T23:59:59.000Z

    X-ray absorption spectroscopy is a powerful tool for the diagnosis of plasmas over a wide range of both temperature and density. However, such a measurement is often limited to probing plasmas with temperatures well below that of the x-ray source in order to avoid object plasma emission lines from obscuring important features of the absorption spectrum. This has excluded many plasmas from being investigated by this technique. We have developed an x-ray spectrometer that provides the ability to record absorption spectra from higher temperature plasmas than the usual approach allows without the risk of data contamination by line radiation emitted by the plasma under study. This is accomplished using a doubly curved mica crystal which is bent both elliptically and cylindrically. We present here the foundational work in the design and development of this spectrometer along with initial results obtained with an aluminum x-pinch as the object plasma.

  11. Apparatus for generating x-ray holograms

    DOE Patents [OSTI]

    Rhodes, C.K.; Boyer, K.; Solem, J.C.; Haddad, W.S.

    1990-09-11T23:59:59.000Z

    Apparatus for x-ray microholography of living biological materials. A Fourier transform holographic configuration is described as being most suitable for the 3-dimensional recording of the physical characteristics of biological specimens. The use of a spherical scatterer as a reference and a charge-coupled device two-dimensional detector array placed in the forward direction relative to the incident x-radiation for viewing electromagnetic radiation simultaneously scattered from both the specimen and the reference scatterer permits the ready reconstruction of the details of the specimen from the fringe pattern detected by the charge-coupled device. For example, by using a nickel reference scatter at 4.5 nm, sufficient reference illumination is provided over a wide enough angle to allow similar resolution in both transverse and longitudinal directions. Both laser and synchrotron radiation sources are feasible for generating microholographs. Operation in the water window (2.4 to 4.5 nm) should provide maximum contrast for features of the specimen and spatial resolution on the order of the wavelength of x-radiation should be possible in all three dimensions, which is sufficient for the visualization of many biological features. It is anticipated that the present apparatus will find utility in other areas as well where microscopic physical details of a specimen are important. A computational procedure which enables the holographic data collected by the detector to be used to correct for misalignments introduced by inexact knowledge of the relative positions of the spherical reference scatterer and the sample under investigation has been developed. If the correction is performed prior to reconstruction, full compensation can be achieved and a faithfully reconstructed image produced. 7 figs.

  12. Apparatus for generating x-ray holograms

    DOE Patents [OSTI]

    Rhodes, Charles K. (Chicago, IL); Boyer, Keith (Los Alamos, NM); Solem, Johndale C. (Los Alamos, NM); Haddad, Waleed S. (Chicago, IL)

    1990-01-01T23:59:59.000Z

    Apparatus for x-ray microholography of living biological materials. A Fourier transform holographic configuration is described as being most suitable for the 3-dimensional recording of the physical characteristics of biological specimens. The use of a spherical scatterer as a reference and a charge-coupled device two-dimensional detector array placed in the forward direction relative to the incident x-radiation for viewing electromagnetic radiation simultaneously scattered from both the specimen and the reference scatterer permits the ready reconstruction of the details of the specimen from the fringe pattern detected by the charge-coupled device. For example, by using a nickel reference scatter at 4.5 nm, sufficient reference illumination is provided over a wide enough angle to allow similar resolution in both transverse and longitudinal directions. Both laser and synchrotron radiation sources are feasible for generating microholographs. Operation in the water window (2.4 to 4.5 nm) should provide maximum contrast for features of the specimen and spatial resolution on the order of the wavelength of x-radiation should be possible in all three dimensions, which is sufficient for the visualization of many biological features. It is anticipated that the present apparatus will find utility in other areas as well where microscopic physical details of a specimen are important. A computational procedure which enables the holographic data collected by the detector to be used to correct for misalignments introduced by inexact knowledge of the relative positions of the spherical reference scatterer and the sample under investigation has been developed. If the correction is performed prior to reconstruction, full compensation can be achieved and a faithfully reconstructed image produced.

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

    SciTech Connect (OSTI)

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

    2014-03-15T23:59:59.000Z

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

  14. X-ray backscatter imaging of nuclear materials

    DOE Patents [OSTI]

    Chapman, Jeffrey Allen; Gunning, John E; Hollenbach, Daniel F; Ott, Larry J; Shedlock, Daniel

    2014-09-30T23:59:59.000Z

    The energy of an X-ray beam and critical depth are selected to detect structural discontinuities in a material having an atomic number Z of 57 or greater. The critical depth is selected by adjusting the geometry of a collimator that blocks backscattered radiation so that backscattered X-ray originating from a depth less than the critical depth is not detected. Structures of Lanthanides and Actinides, including nuclear fuel rod materials, can be inspected for structural discontinuities such as gaps, cracks, and chipping employing the backscattered X-ray.

  15. Gated x-ray detector for the National Ignition Facility

    SciTech Connect (OSTI)

    Oertel, John A.; Aragonez, Robert; Archuleta, Tom; Barnes, Cris; Casper, Larry; Fatherley, Valerie; Heinrichs, Todd; King, Robert; Landers, Doug; Lopez, Frank; Sanchez, Phillip; Sandoval, George; Schrank, Lou; Walsh, Peter; Bell, Perry; Brown, Matt; Costa, Robert; Holder, Joe; Montelongo, Sam; Pederson, Neal [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States); Lawrence Livermore National Laboratory, Livermore, California 94551-0808 (United States); VI Control Systems Ltd., Los Alamos, New Mexico 87544 (United States)

    2006-10-15T23:59:59.000Z

    Two new gated x-ray imaging cameras have recently been designed, constructed, and delivered to the National Ignition Facility in Livermore, CA. These gated x-Ray detectors are each designed to fit within an aluminum airbox with a large capacity cooling plane and are fitted with an array of environmental housekeeping sensors. These instruments are significantly different from earlier generations of gated x-ray images due, in part, to an innovative impedance matching scheme, advanced phosphor screens, pulsed phosphor circuits, precision assembly fixturing, unique system monitoring, and complete remote computer control. Preliminary characterization has shown repeatable uniformity between imaging strips, improved spatial resolution, and no detectable impedance reflections.

  16. X-ray afterglows from gamma-ray bursts

    E-Print Network [OSTI]

    M. Tavani

    1997-03-24T23:59:59.000Z

    We consider possible interpretations of the recently detected X- ray afterglow from the gamma-ray burst source GRB 970228. Cosmological and Galactic models of gamma-ray bursts predict different flux and spectral evolution of X-ray afterglows. We show that models based on adiabatic expansion of relativistic forward shocks require very efficient particle energization or post-burst re-acceleration during the expansion. Cooling neutron star models predict a very distinctive spectral and flux evolution that can be tested in current X-ray data.

  17. Characterization of X-ray generator beam profiles.

    SciTech Connect (OSTI)

    Mitchell, Dean J; Harding, Lee T.; Thoreson, Gregory G.; Theisen, Lisa Anne; Parmeter, John Ethan; Thompson, Kyle Richard

    2013-07-01T23:59:59.000Z

    T to compute the radiography properties of various materials, the flux profiles of X-ray sources must be characterized. This report describes the characterization of X-ray beam profiles from a Kimtron industrial 450 kVp radiography system with a Comet MXC-45 HP/11 bipolar oil-cooled X-ray tube. The empirical method described here uses a detector response function to derive photon flux profiles based on data collected with a small cadmium telluride detector. The flux profiles are then reduced to a simple parametric form that enables computation of beam profiles for arbitrary accelerator energies.

  18. X-ray Diffraction from Membrane Protein Nanocrystals

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengtheningWildfires may contribute more toConsensusX-RayX-RayX-ray

  19. Summary of ISO/TC 201 Standard: XVIII, ISO 19318: 2004 - Surface...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    XVIII, ISO 19318: 2004 - Surface Chemical Analysis - X-Ray Photoelectron Spectroscopy - Summary of ISOTC 201 Standard: XVIII, ISO 19318: 2004 - Surface Chemical Analysis - X-Ray...

  20. Automated suppression of errors in LTP-II slope measurements with x-ray optics

    E-Print Network [OSTI]

    Ali, Zulfiqar

    2011-01-01T23:59:59.000Z

    slope measurements with x-ray optics Zulfiqar Ali, Curtis L.with state-of-the-art x-ray optics. Significant suppressionscanning, metrology of x-ray optics, deflectometry Abstract