National Library of Energy BETA

Sample records for x-ray photoelectron spectroscopy

  1. X-Ray Photoelectron Spectroscopy (XPS) Applied to Soot & What...

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

    Photoelectron Spectroscopy (XPS) Applied to Soot & What It Can Do for You X-Ray Photoelectron Spectroscopy (XPS) Applied to Soot & What It Can Do for You Presentation given at DEER ...

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

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

    Ambient Pressure Photoelectron Spectroscopy Using Soft X-ray and Hard X-ray, and its applications in electrochemistry Friday, December 14, 2012 - 3:30pm SSRL, Bldg. 137, room 322...

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

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

    X-ray, and its applications in electrochemistry | Stanford Synchrotron Radiation Lightsource Ambient Pressure Photoelectron Spectroscopy Using Soft X-ray and Hard X-ray, and its applications in electrochemistry Friday, December 14, 2012 - 3:30pm SSRL, Bldg. 137, room 322 Zhi Liu The synchrotron based ambient pressure x-ray photoelectron spectroscopy (AP-XPS) endstation[1] pioneered at ALS based on differentially pumped electron energy analyzer has been recognized by scientific communities as

  4. 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...

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

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

    Photosynthesis | Stanford Synchrotron Radiation Lightsource 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 carbohydrates and oxygen from water and carbon dioxide using sunlight. Artificial photosynthesis replicates this process to produce energy in the form of usable fuels for human needs. Researches have been developing devices for artificial photosynthesis,

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

    SciTech Connect (OSTI)

    Masuda, Takuya; PRESTO, Japan Science and Technology Agency , 4-1-8 Honcho, Kawaguchi, Saitama 333-0012 ; Yoshikawa, Hideki; Kobata, Masaaki; Kobayashi, Keisuke; Noguchi, Hidenori; PRESTO, Japan Science and Technology Agency , 4-1-8 Honcho, Kawaguchi, Saitama 333-0012; Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810; International Center for Materials Nanoarchitectonics , National Institute for Materials Science , Tsukuba, Ibaraki 305-0044 ; Kawasaki, Tadahiro; Uosaki, Kohei; Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810; International Center for Materials Nanoarchitectonics , National Institute for Materials Science , Tsukuba, Ibaraki 305-0044

    2013-09-09

    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.

  7. Hard x-ray photoelectron spectroscopy using an environmental cell with silicon nitride membrane windows

    SciTech Connect (OSTI)

    Tsunemi, Eika; Watanabe, Yoshio; Oji, Hiroshi; Cui, Yi-Tao; Son, Jin-Young

    2015-06-21

    We applied hard x-ray photoelectron spectroscopy (HAXPES) to a sample under ambient pressure conditions using an environmental cell with an approximately 24 nm-thick SiN{sub x} membrane window. As a model chemical substance, europium (II) iodide (EuI{sub 2}) sealed in the cell with argon gas was investigated with HAXPES to identify the chemical species present inside the cell. The optical and morphological properties of the sample within the cell were measured with optical and fluorescent microscopy, scanning electron microscopy, cathodoluminescence, and energy dispersive x-ray spectrometry. We confirmed the effectiveness of the gas barrier properties of the cell with the SiN{sub x} window and demonstrated its applicability to various other optical and electron measurements as well as HAXPES.

  8. Contact-free pyroelectric measurements using x-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Ehre, D.; Cohen, H.

    2013-07-29

    Non-contact pyroelectricity measurements based on x-ray photoelectron spectroscopy (XPS) are presented. Applied to Lithium Tantalate crystals, we demonstrate how the XPS-derived surface potential provides a simple probe of the desired property, free of all top-contact related difficulties. In particular, the increase in Lithium Tantalate spontaneous polarization under cooling, an experimentally challenging feature, is evaluated. We further inspect the roll of surface contaminants and the control over trapped surface charge in the XPS vacuum environment. Our approach can be extended to other non-contact probes, as well as to measuring additional electrical properties, such as piezoelectricity and ferroelectricity.

  9. Probing hot-electron effects in wide area plasmonic surfaces using X-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Ayas, Sencer; Cupallari, Andi; Dana, Aykutlu

    2014-12-01

    Plasmon enhanced hot carrier formation in metallic nanostructures increasingly attracts attention due to potential applications in photodetection, photocatalysis, and solar energy conversion. Here, hot-electron effects in nanoscale metal-insulator-metal (MIM) structures are investigated using a non-contact X-ray photoelectron spectroscopy based technique using continuous wave X-ray and laser excitations. The effects are observed through shifts of the binding energy of the top metal layer upon excitation with lasers of 445, 532, and 650?nm wavelength. The shifts are polarization dependent for plasmonic MIM grating structures fabricated by electron beam lithography. Wide area plasmonic MIM surfaces fabricated using a lithography free route by the dewetting of evaporated Ag on HfO{sub 2} exhibit polarization independent optical absorption and surface photovoltage. Using a simple model and making several assumptions about the magnitude of the photoemission current, the responsivity and external quantum efficiency of wide area plasmonic MIM surfaces are estimated as 500?nA/W and 11 10{sup ?6} for 445?nm illumination.

  10. Adsorption of 2-propanol on ice probed by ambient pressure X-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Newberg, John T.; Bluhm, Hendrik

    2015-08-18

    The interaction of 2-propanol with ice was examined via ambient pressure X-ray photoelectron spectroscopy (APXPS), a surface sensitive technique that probes the adsorbed 2-propanol directly with submonolayer resolution. Isothermal uptake experiments were performed on vapor deposited ice at 227 K in the presence of the equilibrium water vapor pressure of 0.05 Torr and 2-propanol partial pressures ranging from 5 × 10-5 to 2 × 10-3 Torr. The C 1s APXPS spectra of adsorbed 2-propanol showed two characteristic peaks associated with the COH alcohol group and CMe methyl groups in a 1 : 2 ratio, respectively. Coverage increased with 2-propanol partial pressure and followed first order Langmuir kinetics with a Langmuir constant of K = 6.3 × 103 Torr-1. The 1 : 2 ratio of COH : CMe remained constant with increasing coverage, indicating there is no chemical reaction upon adsorption. The observed Langmuir kinetics using APXPS is consistent with previous observations of other small chain alcohols via indirect adsorption methods using, e.g., Knudsen cell and coated wall flow tube reactors.

  11. Adsorption of 2-propanol on ice probed by ambient pressure X-ray photoelectron spectroscopy

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

    Newberg, John T.; Bluhm, Hendrik

    2015-08-18

    The interaction of 2-propanol with ice was examined via ambient pressure X-ray photoelectron spectroscopy (APXPS), a surface sensitive technique that probes the adsorbed 2-propanol directly with submonolayer resolution. Isothermal uptake experiments were performed on vapor deposited ice at 227 K in the presence of the equilibrium water vapor pressure of 0.05 Torr and 2-propanol partial pressures ranging from 5 × 10-5 to 2 × 10-3 Torr. The C 1s APXPS spectra of adsorbed 2-propanol showed two characteristic peaks associated with the COH alcohol group and CMe methyl groups in a 1 : 2 ratio, respectively. Coverage increased with 2-propanol partialmore » pressure and followed first order Langmuir kinetics with a Langmuir constant of K = 6.3 × 103 Torr-1. The 1 : 2 ratio of COH : CMe remained constant with increasing coverage, indicating there is no chemical reaction upon adsorption. The observed Langmuir kinetics using APXPS is consistent with previous observations of other small chain alcohols via indirect adsorption methods using, e.g., Knudsen cell and coated wall flow tube reactors.« less

  12. Closing the pressure gap in x-ray photoelectron spectroscopy by membrane hydrogenation

    SciTech Connect (OSTI)

    Delmelle, Renaud; Borgschulte, Andreas; Probst, Benjamin; Alberto, Roger; Zttel, Andreas; Bleiner, Davide

    2015-05-15

    Comprehensive studies of gas-solid reactions require the in-situ interaction of the gas at a pressure beyond the operating pressure of ultrahigh vacuum (UHV) X-ray photoelectron spectroscopy (XPS). The recent progress of near ambient pressure XPS allows to dose gases to the sample up to a pressure of 20 mbar. The present work describes an alternative to this experimental challenge, with a focus on H{sub 2} as the interacting gas. Instead of exposing the sample under investigation to gaseous hydrogen, the sample is in contact with a hydrogen permeation membrane, through which hydrogen is transported from the outside to the sample as atomic hydrogen. Thereby, we can reach local hydrogen concentrations at the sample inside an UHV chamber, which is equipped with surface science tools, and this corresponds to a hydrogen pressure up to 1 bar without affecting the sensitivity or energy resolution of the spectrometer. This experimental approach is validated by two examples, that is, the reduction of a catalyst precursor for CO{sub 2} hydrogenation and the hydrogenation of a water reduction catalyst for photocatalytic H{sub 2} production, but it opens the possibility of the new in situ characterisation of energy materials and catalysts.

  13. Band bending at ferroelectric surfaces and interfaces investigated by x-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Apostol, Nicoleta Georgiana

    2014-11-24

    This work reports on the use of X-ray photoelectron spectroscopy to quantify band bending at ferroelectric free surfaces and at their interfaces with metals. Surfaces exhibiting out-of-plane ferroelectric polarization are characterized by a band bending, due to the formation of a dipole layer at the surface, composed by the uncompensated polarization charges (due to ionic displacement) and to the depolarization charge sheet of opposite sign, composed by mobile charge carriers, which migrate near surface, owing to the depolarization electric field. To this surface band bending due to out-of-plane polarization states, metal-semiconductor Schottky barriers must be considered additionally when ferroelectrics are covered by metal layers. It is found that the net band bending is not always an algebraic sum of the two effects discussed above, since sometimes the metal is able to provide additional charge carriers, which are able to fully compensate the surface charge of the ferroelectric, up to the vanishing of the ferroelectric band bending. The two cases which will be discussed in more detail are Au and Cu deposited by molecular beam epitaxy on PbZr{sub 0.2}Ti{sub 0.8}O{sub 3}(001) single crystal thin layers, prepared by pulsed laser deposition. Gold forms unconnected nanoparticles, and their effect on the band bending is the apparition of a Schottky band bending additional to the band bending due to the out-of-plane polarization. Copper, starting with a given thickness, forms continuous metal layers connected to the ground of the system, and provide electrons in sufficient quantity to compensate the band bending due to the out-of-plane polarization.

  14. X-ray Photoelectron Spectroscopy study of the compatibility of the explosive PETN with candidate plastic bonding materials

    SciTech Connect (OSTI)

    Vannet, M.D.; Wang, P.S.; Moddeman, W.E.; Bowling, W.C.

    1985-01-01

    The compatibility of the explosive PETN with two plastic bonding materials, ethyl cellulose and a halogenated vinyl polymer (FPC 461), was determined by X-ray Photoelectron Spectroscopy (XPS). Both were found to coat the PETN crystals, and no change in chemical composition was found in the PETN or the plastic due to either the process or their mutual presence. 3 refs., 1 fig., 1 tab.

  15. An X-ray photoelectron spectroscopy study of the hydration of C{sub 2}S thin films

    SciTech Connect (OSTI)

    Rheinheimer, Vanessa; Casanova, Ignasi

    2014-06-01

    Electron-beam evaporation was used to produce thin films of ?-dicalcium silicate. Chemical and mineralogical compositions were characterized by X-ray photoelectron spectroscopy (XPS) and grazing-angle X-ray diffraction (GAXRD), respectively. Results show that no fractionation occurs during evaporation and isostructural condensation of the material as synthesized films have the same composition as the initial bulk material. Samples were gradually hydrated under saturated water spray conditions and analyzed with XPS. Polymerization of the silicate chains due to hydration, and subsequent formation of C-S-H, has been monitored through evaluation of energy shifts on characteristic silicon peaks. Quantitative analyses show changes on the surface by the reduction of the Ca/Si ratio and an increase on the difference between binding energies of bridging and non-bridging oxygen. Finally, SEM/FIB observation shows clear differences between the surface and cross section of the initial sample and the reacted sample.

  16. X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy investigation of Al-related dipole at the HfO{sub 2}/Si interface

    SciTech Connect (OSTI)

    Zhu, L. Q.; Barrett, N.; Jegou, P.

    2009-01-15

    The presence of an ultrathin oxide layer at the high-k/SiO{sub 2} interface may result in an interfacial dipole related to the specific high-k dielectric used for the gate stacks. 1 nm HfO{sub 2}/x nmAl{sub 2}O{sub 3}/SiO{sub 2}/Si stacks with different x values (x=0, 0.4, 0.8, 1.2) have been prepared by atomic layer deposition. Using photoelectron spectroscopy, an Al-related interfacial dipole in the HfO{sub 2}/Al{sub 2}O{sub 3}/SiO{sub 2} gate stack has been identified. X-ray photoelectron spectroscopy analysis shows that the dipole is correlated with the formation of an interfacial Al-silicate. The dipole is located at the Al-silicate interface between Al{sub 2}O{sub 3} and SiO{sub 2}, and its strength increases with the increase in Al{sub 2}O{sub 3} thickness because of Al silicate growth. Such Al-related interfacial dipole should have potential applications in future positive metal-oxide-semiconductor devices.

  17. X-ray photoelectron spectroscopy studies on Pd doped SnO{sub 2} liquid petroleum gas sensor

    SciTech Connect (OSTI)

    Phani, A.R.

    1997-10-01

    The present investigation deals with the electrical response of palladium doped tin oxide, as a means of improving the selectivity for liquid petroleum gas (LPG) in the presence of CO, CH{sub 4}. The sensor element with the composition of Pd(1.5 wt{percent}) in the base material SnO{sub 2} sintered at 800{degree}C, has shown a high sensitivity towards LPG with a negligible cross interference of CO and CH{sub 4} at an operating temperature of 350{degree}C. This greatly suggests the possibility of utilizing the sensor for the detection of LPG. X-ray photoelectron spectroscopy studies have been carried out to determine the possible chemical species involved in the gas-solid interaction and the enhancing mechanism of the Pd doped SnO{sub 2} sensor element, towards LPG sensitivity. {copyright} {ital 1997 American Institute of Physics.}

  18. Spectroscopic evidence for Ag(III) in highly oxidized silver films by x-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Kaspar, Tiffany C.; Droubay, Timothy C.; Chambers, Scott A.; Bagus, Paul S.

    2010-12-16

    In situ x-ray photoelectron spectroscopy (XPS) was utilized to identify the chemical state of silver in a range of silver oxide thin films obtained by co-deposition of silver and atomic oxygen. A highly oxidized silver species was observed at an unexpectedly low Ag 3d5/2 binding energy (BE) of 366.8 eV with an associated broad satellite at 368.2 eV; this species was assigned as Ag(III). It was found to be highly unstable in vacuum, but could be regenerated by further exposure to atomic oxygen. Both BE shifts and intensity changes of the O 1s peak were found to correlate with changes in the silver oxidation state. Theoretical calculations of the expected XPS of high spin Ag(III) provide insight into the significance of satellite structure and shake features in the Ag 3d spectra.

  19. ANALYSIS OF PASSIVATED SURFACES FOR MASS SPECTROMETER INLET SYSTEMS BY AUGER ELECTRON AND X-RAY PHOTOELECTRON SPECTROSCOPY

    SciTech Connect (OSTI)

    Ajo, H.; Clark, E.

    2010-09-01

    Stainless steel coupons approximately 0.5' in diameter and 0.125' thick were passivated with five different surface treatments and an untreated coupon was left as a control. These surface treatments are being explored for use in tritium storage containers. These coupons were made to allow surface analysis of the surface treatments using well-know surface analysis techniques. Depth profiles using Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) were performed on these coupons to characterize the surface and near surface regions. Scanning electron microscope (SEM) images were collected as well. All of the surface treatments studied here appear to change the surface morphology dramatically, as evidenced by lack of tool marks on the treated samples. In terms of the passivation treatment, Vendors A-D appeared to have oxide layers that were very similar in thickness to each other (0.7-0.9 nm thick) as well as the untreated samples (the untreated sample oxide layers appeared to be somewhat larger). Vendor E's silicon coating appears to be on the order of 200 nm thick.

  20. NREL: Measurements and Characterization - X-Ray and UV Photoelectron

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

    Spectroscopy X-Ray and UV Photoelectron Spectroscopy Example of graph made with cluster tool; plots counts (Y-axis) vs. binding energy (X-axis) for PET Carbon 1S. High-resolution XPS spectra of carbon 1s from polyethylene terephthalate backsheet material, showing excellent quantitative agreement between measured and predicted peak area ratios. Subtle differences in polymer functionality are assessed by deviations from stoichiometry. In photoemission techniques, we use either X-rays or

  1. 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

    2015-05-07

    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 Pt⁴⁺ 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

  2. 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.; Ahmed, Doaa; Eldakrouri, Ashraf; Department of Optometry and Vision Science, College of Applied Medical Science, King Saud University, Riyadh

    2013-06-21

    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.

  3. SMB, X-ray Absorption Spectroscopy

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

    Absorption Spectroscopy X-ray Absorption Spectroscopy X-ray absorption spectroscopy (XAS) is a well-established technique for simultaneous local geometric and electronic structure...

  4. Conduction band offset at GeO{sub 2}/Ge interface determined by internal photoemission and charge-corrected x-ray photoelectron spectroscopies

    SciTech Connect (OSTI)

    Zhang, W. F.; Nishimula, T.; Nagashio, K.; Kita, K.; Toriumi, A.

    2013-03-11

    We report a consistent conduction band offset (CBO) at a GeO{sub 2}/Ge interface determined by internal photoemission spectroscopy (IPE) and charge-corrected X-ray photoelectron spectroscopy (XPS). IPE results showed that the CBO value was larger than 1.5 eV irrespective of metal electrode and substrate type variance, while an accurate determination of valence band offset (VBO) by XPS requires a careful correction of differential charging phenomena. The VBO value was determined to be 3.60 {+-} 0.2 eV by XPS after charge correction, thus yielding a CBO (1.60 {+-} 0.2 eV) in excellent agreement with the IPE results. Such a large CBO (>1.5 eV) confirmed here is promising in terms of using GeO{sub 2} as a potential passivation layer for future Ge-based scaled CMOS devices.

  5. 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; Li Xiaomin; Gan Xiaoyan; Sellers, Ian R.

    2012-12-24

    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.

  6. 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.; Ahlund, J.; Backlund, K.; Karlsson, P. G.; Adiga, V. P.; Streller, F.; Wannberg, B.; Carpick, R. W.

    2012-09-15

    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.

  7. Band structure of the epitaxial Fe/MgO/GaAs(001) tunnel junction studied by x-ray and ultraviolet photoelectron spectroscopies

    SciTech Connect (OSTI)

    Lu, Y.; Le Breton, J. C.; Turban, P.; Lepine, B.; Schieffer, P.; Jezequel, G.

    2006-10-09

    The electronic band structure in the epitaxial Fe/MgO/GaAs(001) tunnel junction has been studied by x-ray and ultraviolet photoelectron spectroscopy measurements. The Schottky barrier height (SBH) of Fe on MgO/GaAs heterostructure is determined to be 3.3{+-}0.1 eV, which sets the Fe Fermi level at about 0.3 eV above the GaAs valence band maximum. This SBH is also exactly the same as that measured from Fe on MgO monocrystal. After Fe deposition, no band bending change is observed in MgO and GaAs underlayers. On the contrary, Au and Al depositions led to clear variation of the band bending in both MgO and GaAs layers. This effect is analyzed as a fingerprint of defect states at the MgO/GaAs interface.

  8. Analysis of passivated A-286 stainless steel surfaces for mass spectrometer inlet systems by Auger electron and X-ray photoelectron spectroscopy and scanning electron microscopy

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

    Ajo, Henry; Blankenship, Donnie; Clark, Elliot

    2014-07-25

    In this study, various commercially available surface treatments are being explored for use on stainless steel components in mass spectrometer inlet systems. Type A-286 stainless steel coupons, approximately 12.5 mm in diameter and 3 mm thick, were passivated with one of five different surface treatments; an untreated coupon served as a control. The surface and near-surface microstructure and chemistry of the coupons were investigated using sputter depth profiling using Auger electron spectroscopy, x-ray photoelectron spectroscopy, and scanning electron microscopy (SEM). All the surface treatments studied appeared to change the surface morphology dramatically, as evidenced by lack of tool marks onmore » the treated samples in SEM images. In terms of the passivation treatment, Vendors A-D appeared to have oxide layers that were very similar in thickness to each other (0.7–0.9 nm thick), as well as to the untreated samples (the untreated sample oxide layers appeared to be somewhat larger). Vendor E’s silicon coating appears to be on the order of 200 nm thick.« less

  9. Analysis of passivated A-286 stainless steel surfaces for mass spectrometer inlet systems by Auger electron and X-ray photoelectron spectroscopy and scanning electron microscopy

    SciTech Connect (OSTI)

    Ajo, Henry; Blankenship, Donnie; Clark, Elliot

    2014-07-25

    In this study, various commercially available surface treatments are being explored for use on stainless steel components in mass spectrometer inlet systems. Type A-286 stainless steel coupons, approximately 12.5 mm in diameter and 3 mm thick, were passivated with one of five different surface treatments; an untreated coupon served as a control. The surface and near-surface microstructure and chemistry of the coupons were investigated using sputter depth profiling using Auger electron spectroscopy, x-ray photoelectron spectroscopy, and scanning electron microscopy (SEM). All the surface treatments studied appeared to change the surface morphology dramatically, as evidenced by lack of tool marks on the treated samples in SEM images. In terms of the passivation treatment, Vendors A-D appeared to have oxide layers that were very similar in thickness to each other (0.7–0.9 nm thick), as well as to the untreated samples (the untreated sample oxide layers appeared to be somewhat larger). Vendor E’s silicon coating appears to be on the order of 200 nm thick.

  10. Effects of Pt and Zr on the oxidation behavior of FeTbCo magneto-optic films: X-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Majumdar, D.; Hatwar, T. K.

    1989-07-01

    We report the effects of Pt and Zr on the oxidation behavior of FeTbCo magneto-optic films. The addition of 10 at. % Pt or Zr increased environmental stability without significantly affecting the magneto-optic properties. X-ray photoelectron spectroscopy was used to study /ital in/ /ital situ/ oxidation of clean FeTbCoPt and FeTbCoZr films under 5/times/10/sup /minus/7/ Torr of oxygen at room temperature. Pt and Zr played different roles in increasing the oxidation resistance of the alloy. In the FeTbCoPt alloy, Pt reduced the oxygen uptake and retarded the oxidation kinetics of Fe. No oxidation of Pt was observed. In the FeTbCoZr alloy, Zr oxidized readily and segregated to the surface to form a protective layer. The Tb/Fe ratio at the surface increased with oxygen exposure in both alloys but at a faster rate in the FeTbCoPt alloy than in the FeTbCoZr alloy.

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

    SciTech Connect (OSTI)

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

    2004-02-28

    High-power lithium-ion cells for transportation applications are being developed and studied at Argonne National Laboratory. The current generation of cells containing LiNi{sub 0.8}Co{sub 0.15}Al{sub 0.05}O{sub 2}-based cathodes, graphite-based anodes, and LiPF6-based electrolytes show loss of capacity and power during accelerated testing at elevated temperatures. Negative electrode samples harvested from some cells that showed varying degrees of power and capacity fade were examined by X-ray photoelectron spectroscopy (XPS). The samples exhibited a surface film on the graphite, which was thicker on samples from cells that showed higher fade. Furthermore, solvent-based compounds were dominant on samples from low power fade cells, whereas LiPF{sub 6}-based products were dominant on samples from high power fade cells. The effect of sample rinsing and air exposure is discussed. Mechanisms are proposed to explain the formation of compounds suggested by the XPS data.

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

    SciTech Connect (OSTI)

    Arima, Kenta; Jiang, Peng; Deng, Xingyi; Bluhm, Henrik; Salmeron, Miquel

    2010-03-31

    The adsorption of water on KBr thin films evaporated onto SiO2 was investigated as a function of relative humidity (RH) by ambient pressure X-ray photoelectron spectroscopy. At 30percent RH adsorbed water reaches a coverage of approximately one monolayer. As the humidity continues to increase, the coverage of water remains constant or increases very slowly until 60percent RH, followed by a rapid increase up to 100percent RH. At low RH a significant number of the Br atoms are lost due to irradiation damage. With increasing humidity solvation increases ion mobility and gives rise to a partial recovery of the Br/K ratio. Above 60percent RH the increase of the Br/K ratio accelerates. Above the deliquescence point (85percent RH), the thickness of the water layer continues to increase and reaches more than three layers near saturation. The enhancement of the Br/K ratio at this stage is roughly a factor 2.3 on a 0.5 nm KBr film, indicating a strong preferential segregation of Br ions to the surface of the thin saline solution on SiO2.

  13. Electrical conductivity anomaly and X-ray photoelectron spectroscopy investigation of YCr{sub 1?x}Mn{sub x}O{sub 3} negative temperature coefficient ceramics

    SciTech Connect (OSTI)

    Zhang, Bo; University of Chinese Academy of Sciences, Beijing 100049 ; Zhao, Qing; Chang, Aimin E-mail: wuy@alfred.edu; Li, Yiyu; Liu, Yin; Wu, Yiquan E-mail: wuy@alfred.edu

    2014-03-10

    Electrical conductivity anomaly of perovskite-type YCr{sub 1?x}Mn{sub x}O{sub 3} negative temperature coefficient (NTC) ceramics produced by spark plasma sintering (SPS) has been investigated by using defect chemistry theory combination with X-ray photoelectron spectroscopy (XPS) analysis. From the results of the ln?-1/T curves and the XPS analysis, it can be considered that YCr{sub 1?x}Mn{sub x}O{sub 3} ceramics exhibit the hopping conductivity. The major carriers in YCrO{sub 3} are holes, which are compensated by the oxygen vacancies produced due to the introduction of Mn ions. The Mn{sup 4+} ion contents increase monotonically in the range of 0.2???x???0.5. The resistivity increases at first and then decreases with increasing Mn contents, which has the same varying tendency with activation energy. The electrical conductivity anomaly appearing in these ceramics may be due to the variation of Cr{sup 4+} and Mn{sup 4+} ions concentration as Mn content changes.

  14. In Situ Observation of Water Dissociation with Lattice Incorporation at FeO Particle Edges Using Scanning Tunneling Microscopy and X-ray Photoelectron Spectroscopy

    SciTech Connect (OSTI)

    Deng, Xingyi; Lee, Junseok; Wang, Congjun; Matranga, Christopher; Aksoy, Funda; Liu, Zhi

    2011-03-15

    The dissociation of H2O and formation of adsorbed hydroxyl groups, on FeO particles grown on Au(111) were identified with in situ,: X:ray photoelectron spectroscopy (XPS) at water pressures ranging from 3 x 10-8 to 0.1 Torr. The facile dissociation of H2O takes place at FeO particle edges, and it was successfully observed in situ With atomically resolved scanning tunneling microscopy (STM). The in situ STM studies show that adsorbed hydroxyl groups were formed exclusively along the edges of the FeO particles with the 0 atom becoming directly incorporated into the oxide crystalline lattice The STM results are consistent with coordinatively unsaturated ferrous (CUF) sites along the FeO particle edge causing the observed reactivity with H2O. Our results also directly illustrate how structural defects and under.-coordinated sites participate in chemical reactions.

  15. Femtosecond X-ray Absorption Spectroscopy at a Hard X-ray Free...

    Office of Scientific and Technical Information (OSTI)

    Femtosecond X-ray Absorption Spectroscopy at a Hard X-ray Free Electron Laser: Application to Spin Crossover Dynamics Citation Details In-Document Search Title: Femtosecond X-ray...

  16. Hard x-ray delay line for x-ray photon correlation spectroscopy...

    Office of Scientific and Technical Information (OSTI)

    Hard x-ray delay line for x-ray photon correlation spectroscopy and jitter-free pump-probe experiments at LCLS Citation Details In-Document Search Title: Hard x-ray delay line for...

  17. X-ray photoelectron spectroscopic studies on yttria, zirconia, and yttria-stabilized zirconia

    SciTech Connect (OSTI)

    Majumdar, D. ); Chatterjee, D. )

    1991-07-15

    Surfaces of yttria, zirconia, and yttria-stabilized zirconia were studied using x-ray photoelectron spectroscopy. An almost threefold increase in the surface yttrium concentration was observed in the yttria-stabilized zirconia samples. The core level binding energies of yttrium, zirconium, and oxygen ions in yttria-stabilized zirconia showed chemical shifts. Valence bands and Auger parameters were monitored for the monoclinic and the tetragonal phases of zirconia. Characteristic differences were observed for the two phases due to their different oxygen coordination. The results were used to identify surface phase transitions which were difficult to detect by x-ray diffraction.

  18. X-ray transient absorption and picosecond IR spectroscopy of...

    Office of Scientific and Technical Information (OSTI)

    X-ray transient absorption and picosecond IR spectroscopy of fulvalene(tetracarbonyl)diruthenium on photoexcitation Citation Details In-Document Search Title: X-ray transient ...

  19. Effect of Cl{sub 2}- and HBr-based inductively coupled plasma etching on InP surface composition analyzed using in situ x-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Bouchoule, S.; Vallier, L.; Patriarche, G.; Chevolleau, T.; Cardinaud, C.

    2012-05-15

    A Cl{sub 2}-HBr-O{sub 2}/Ar inductively coupled plasma (ICP) etching process has been adapted for the processing of InP-based heterostructures in a 300-mm diameter CMOS etching tool. Smooth and anisotropic InP etching is obtained at moderate etch rate ({approx}600 nm/min). Ex situ x-ray energy dispersive analysis of the etched sidewalls shows that the etching anisotropy is obtained through a SiO{sub x} passivation mechanism. The stoichiometry of the etched surface is analyzed in situ using angle-resolved x-ray photoelectron spectroscopy. It is observed that Cl{sub 2}-based ICP etching results in a significantly P-rich surface. The phosphorous layer identified on the top surface is estimated to be {approx}1-1.3-nm thick. On the other hand InP etching in HBr/Ar plasma results in a more stoichiometric surface. In contrast to the etched sidewalls, the etched surface is free from oxides with negligible traces of silicon. Exposure to ambient air of the samples submitted to Cl{sub 2}-based chemistry results in the complete oxidation of the P-rich top layer. It is concluded that a post-etch treatment or a pure HBr plasma step may be necessary after Cl{sub 2}-based ICP etching for the recovery of the InP material.

  20. A combined capacitance-voltage and hard x-ray photoelectron spectroscopy characterisation of metal/Al{sub 2}O{sub 3}/In{sub 0.53}Ga{sub 0.47}As capacitor structures

    SciTech Connect (OSTI)

    Lin, Jun; Povey, Ian M.; Hurley, Paul K.; Walsh, Lee; Hughes, Greg; Woicik, Joseph C.; O'Regan, Terrance P.

    2014-07-14

    Capacitance-Voltage (C-V) characterization and hard x-ray photoelectron spectroscopy (HAXPES) measurements have been used to study metal/Al{sub 2}O{sub 3}/In{sub 0.53}Ga{sub 0.47}As capacitor structures with high (Ni) and low (Al) work function metals. The HAXPES measurements observe a band bending occurring prior to metal deposition, which is attributed to a combination of fixed oxide charges and interface states of donor-type. Following metal deposition, the Fermi level positions at the Al{sub 2}O{sub 3}/In{sub 0.53}Ga{sub 0.47}As interface move towards the expected direction as observed from HAXPES measurements. The In{sub 0.53}Ga{sub 0.47}As surface Fermi level positions determined from both the C-V analysis at zero gate bias and HAXPES measurements are in reasonable agreement. The results are consistent with the presence of electrically active interface states at the Al{sub 2}O{sub 3}/In{sub 0.53}Ga{sub 0.47}As interface and suggest an interface state density increasing towards the In{sub 0.53}Ga{sub 0.47}As valence band edge.

  1. 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 Bertaud, Thomas; Walczyk, Damian; Calka, Pauline; Walczyk, Christian; Thiess, Sebastian; Alff, Lambert; Schroeder, Thomas

    2014-05-28

    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.

  2. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy

    SciTech Connect (OSTI)

    Miaja-Avila, L.; O'Neil, G. C.; Uhlig, J.; Cromer, C. L.; Dowell, M. L.; Jimenez, R.; Hoover, A. S.; Silverman, K. L.; Ullom, J. N.

    2015-03-02

    We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ~106 photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >107 laser pulses, we also present data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments.

  3. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy

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

    Miaja-Avila, L.; O'Neil, G. C.; Uhlig, J.; Cromer, C. L.; Dowell, M. L.; Jimenez, R.; Hoover, A. S.; Silverman, K. L.; Ullom, J. N.

    2015-03-02

    We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ~106 photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >107 laser pulses, we also presentmore » data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments.« less

  4. XRMS: X-Ray Spectroscopy of Magnetic Solids

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

    XRMS: X-Ray Spectroscopy of Magnetic Solids October 22-23, 2011 SLAC National Accelerator Laboratory, Menlo Park, CA More information...

  5. 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.

    2004-11-01

    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.

  6. X-ray spectroscopy of manganese clusters

    SciTech Connect (OSTI)

    Grush, M.M.

    1996-06-01

    Much of this thesis represents the groundwork necessary in order to probe Mn clusters more productively than with conventional Mn K-edge XAS and is presented in Part 1. Part 2 contains the application of x-ray techniques to Mn metalloproteins and includes a prognosis at the end of each chapter. Individual Mn oxidation states are more readily distinguishable in Mn L-edge spectra. An empirical mixed valence simulation routine for determining the average Mn oxidation state has been developed. The first Mn L-edge spectra of a metalloprotein were measured and interpreted. The energy of Mn K{beta} emission is strongly correlated with average Mn oxidation state. K{beta} results support oxidation states of Mn(III){sub 2}(IV){sub 2} for the S{sub 1} state of Photosystem II chemical chemically reduced preparations contain predominantly Mn(II). A strength and limitation of XAS is that it probes all of the species of a particular element in a sample. It would often be advantageous to selectively probe different forms of the same element. The first demonstration that chemical shifts in x-ray fluorescence energies can be used to obtain oxidation state-selective x-ray absorption spectra is presented. Spin-dependent spectra can also be used to obtain a more simplified picture of local structure. The first spin-polarized extended x-ray absorption fine structure using Mn K{beta} fluorescence detection is shown.

  7. Hard x-ray photoelectron spectroscopy study of Ge{sub 2}Sb{sub 2}Te{sub 5}; as-deposited amorphous, crystalline, and laser-reamorphized

    SciTech Connect (OSTI)

    Richter, Jan H. Tominaga, Junji; Fons, Paul; Kolobov, Alex V.; Ueda, Shigenori; Yoshikawa, Hideki; Yamashita, Yoshiyuki; Ishimaru, Satoshi; Kobayashi, Keisuke

    2014-02-10

    We have investigated the electronic structure of as-deposited, crystalline, and laser-reamorphized Ge{sub 2}Sb{sub 2}Te{sub 5} using high resolution, hard x-ray photoemission spectroscopy. A shift in the Fermi level as well as a broadening of the spectral features in the valence band and the Ge 3d level between the amorphous and crystalline state is observed. Upon amorphization, Ge 3d and Sb 4d spectra show a surprisingly small breaking of resonant bonds and changes in the bonding character as evidenced by the very similar density of states in all cases.

  8. X-ray transient absorption and picosecond IR spectroscopy of

    Office of Scientific and Technical Information (OSTI)

    fulvalene(tetracarbonyl)diruthenium on photoexcitation (Journal Article) | SciTech Connect X-ray transient absorption and picosecond IR spectroscopy of fulvalene(tetracarbonyl)diruthenium on photoexcitation Citation Details In-Document Search Title: X-ray transient absorption and picosecond IR spectroscopy of fulvalene(tetracarbonyl)diruthenium on photoexcitation Authors: Harpham, M. R. ; Nguyen, S. C. ; Hou, Z. ; Grossman, J. C. ; Harris, C. B. ; Mara, M. W. ; Stickrath, A. B. ; Kanai, Y. ;

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

    SciTech Connect (OSTI)

    Guo, J.-H.

    2005-07-30

    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.

  10. New focusing multilayer structures for X-ray plasma spectroscopy

    SciTech Connect (OSTI)

    Bibishkin, M S; Luchin, V I; Salashchenko, N N; Chernov, V V; Chkhalo, N I; Kazakov, E D; Shevelko, A P

    2008-02-28

    New focusing short-period multilayer structures are developed which opens up wide possibilities for X-ray and VUV spectroscopy. Multilayer structures are deposited on a flat surface of a mica crystal which is then bent to a small-radius cylinder. The use of this structure in a von Hamos spectrometer for X-ray laser plasma diagnostics is demonstrated. (interaction of laser radiation with matter. laser plasma)

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

    SciTech Connect (OSTI)

    Katayama, Tetsuo; Togashi, Tadashi; Tono, Kensuke; Kameshima, Takashi; Inubushi, Yuichi; Sato, Takahiro; Hatsui, Takaki; Yabashi, Makina; Obara, Yuki; Misawa, Kazuhiko; Bhattacharya, Atanu; Kurahashi, Naoya; Ogi, Yoshihiro; Suzuki, Toshinori; Molecular Reaction Dynamics Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako 351-0198

    2013-09-23

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

  12. A laboratory-based hard x-ray monochromator for high-resolution x-ray emission spectroscopy and x-ray absorption near edge structure measurements

    SciTech Connect (OSTI)

    Seidler, G. T. Mortensen, D. R.; Remesnik, A. J.; Pacold, J. I.; Ball, N. A.; Barry, N.; Styczinski, M.; Hoidn, O. R.

    2014-11-15

    We report the development of a laboratory-based Rowland-circle monochromator that incorporates a low power x-ray (bremsstrahlung) tube source, a spherically bent crystal analyzer, and an energy-resolving solid-state detector. This relatively inexpensive, introductory level instrument achieves 1-eV energy resolution for photon energies of ?5 keV to ?10 keV while also demonstrating a net efficiency previously seen only in laboratory monochromators having much coarser energy resolution. Despite the use of only a compact, air-cooled 10 W x-ray tube, we find count rates for nonresonant x-ray emission spectroscopy comparable to those achieved at monochromatized spectroscopy beamlines at synchrotron light sources. For x-ray absorption near edge structure, the monochromatized flux is small (due to the use of a low-powered x-ray generator) but still useful for routine transmission-mode studies of concentrated samples. These results indicate that upgrading to a standard commercial high-power line-focused x-ray tube or rotating anode x-ray generator would result in monochromatized fluxes of order 10{sup 6}10{sup 7} photons/s with no loss in energy resolution. This work establishes core technical capabilities for a rejuvenation of laboratory-based hard x-ray spectroscopies that could have special relevance for contemporary research on catalytic or electrical energy storage systems using transition-metal, lanthanide, or noble-metal active species.

  13. In Operando Soft X-ray Spectroscopy of 3D Graphene Supercapacitor...

    Office of Scientific and Technical Information (OSTI)

    In Operando Soft X-ray Spectroscopy of 3D Graphene Supercapacitor Electrodes Citation Details In-Document Search Title: In Operando Soft X-ray Spectroscopy of 3D Graphene ...

  14. Hubbard model corrections in real-space x-ray spectroscopy theory...

    Office of Scientific and Technical Information (OSTI)

    Hubbard model corrections in real-space x-ray spectroscopy theory Citation Details In-Document Search Title: Hubbard model corrections in real-space x-ray spectroscopy theory ...

  15. X-ray line polarization spectroscopy of Li-like satellite line...

    Office of Scientific and Technical Information (OSTI)

    X-ray line polarization spectroscopy of Li-like satellite line spectra Citation Details In-Document Search Title: X-ray line polarization spectroscopy of Li-like satellite line ...

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

    Office of Scientific and Technical Information (OSTI)

    Conference: Soft X-Ray and Vacuum Ultraviolet Based Spectroscopy of the Actinides Citation Details In-Document Search Title: Soft X-Ray and Vacuum Ultraviolet Based Spectroscopy of ...

  17. Calibration of Spherically Bent Crystals used in X-Ray Spectroscopy...

    Office of Scientific and Technical Information (OSTI)

    Calibration of Spherically Bent Crystals used in X-Ray Spectroscopy. Citation Details In-Document Search Title: Calibration of Spherically Bent Crystals used in X-Ray Spectroscopy. ...

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

    Office of Scientific and Technical Information (OSTI)

    Conference: Soft X-Ray and Vacuum Ultraviolet Based Spectroscopy of the Actinides Citation Details In-Document Search Title: Soft X-Ray and Vacuum Ultraviolet Based Spectroscopy of...

  19. A new spectrometer design for the x-ray spectroscopy of laser...

    Office of Scientific and Technical Information (OSTI)

    the x-ray spectroscopy of laser-produced plasmas with high (sub-ns) time resolution Citation Details In-Document Search Title: A new spectrometer design for the x-ray ...

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

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect X-ray imaging crystal spectroscopy for use in plasma transport research Citation Details In-Document Search Title: X-ray imaging crystal spectroscopy for use in plasma transport research 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

  1. Gas cell for in situ soft X-ray transmission-absorption spectroscopy...

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

    cell for in situ soft X-ray transmission-absorption spectroscopy of materials Previous ... Abstract: A simple gas cell design, constructed primarily from commercially available ...

  2. SSRL School on Synchrotron X-ray Spectroscopy Techniques in Environmen...

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

    Transportation Tourism & Dining SSRL School on Synchrotron X-ray Spectroscopy Techniques in Environmental and Materials Sciences: Theory and Application June 2-5, 2009 Group...

  3. Stimulated X-Ray Emission for Spectroscopy | Stanford Synchrotron...

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

    Room 108A Speaker: Clemens Weninger, Max Planck Institute for the Physics of Complex Systems Program Description The recent advance of x-ray free electron lasers (XFELs)...

  4. Staff Research Physicist (X-Ray Spectroscopy) | Princeton Plasma...

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

    of X-ray spectrometers for high energy density plasma at the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL, Livermore, California). In...

  5. Near-Edge X-Ray Absorption Fine Structure Spectroscopy of Diamondoid Thiol Monolayers on Gold

    SciTech Connect (OSTI)

    Willey, T.M.; Fabbri, J.D.; Lee, J.R.I.; Schreiner, P.R.; Fokin, A.A.; Tkachenko, B.A.; Fokina, N.A.; Dahl, J.E.P.; Carlson, R.M.K.; Vance, A.L.; Yang, W.; Terminello, L.J.; Buuren, T.van; Melosh, N.A.

    2009-05-26

    Diamondoids, hydrocarbon molecules with cubic-diamond-cage structures, have unique properties with potential value for nanotechnology. The availability and ability to selectively functionalize this special class of nanodiamond materials opens new possibilities for surface modification, for high-efficiency field emitters in molecular electronics, as seed crystals for diamond growth, or as robust mechanical coatings. The properties of self-assembled monolayers (SAMs) of diamondoids are thus of fundamental interest for a variety of emerging applications. This paper presents the effects of thiol substitution position and polymantane order on diamondoid SAMs on gold using near-edge X-ray absorption fine structure spectroscopy (NEXAFS) and X-ray photoelectron spectroscopy (XPS). A framework to determine both molecular tilt and twist through NEXAFS is presented and reveals highly ordered diamondoid SAMs, with the molecular orientation controlled by the thiol location. C 1s and S 2p binding energies are lower in adamantane thiol than alkane thiols on gold by 0.67 {+-} 0.05 and 0.16 {+-} 0.04 eV, respectively. These binding energies vary with diamondoid monolayer structure and thiol substitution position, consistent with different degrees of steric strain and electronic interaction with the substrate. This work demonstrates control over the assembly, in particular the orientational and electronic structure, providing a flexible design of surface properties with this exciting new class of diamond nanoparticles.

  6. Near-Edge X-ray Absorption Fine Structure Spectroscopy of Diamondoid Thiol Monolayers on Gold

    SciTech Connect (OSTI)

    Willey, T M; Fabbri, J; Lee, J I; Schreiner, P; Fokin, A A; Tkachenko, B A; Fokina, N A; Dahl, J; Carlson, B; Vance, A L; Yang, W; Terminello, L J; van Buuren, T; Melosh, N

    2007-11-27

    Diamondoids, hydrocarbon molecules with cubic-diamond-cage structures, have unique properties with potential value for nanotechnology. The availability and ability to selectively functionalize this special class of nanodiamond materials opens new possibilities for surface-modification, for high-efficiency field emitters in molecular electronics, as seed crystals for diamond growth, or as robust mechanical coatings. The properties of self-assembled monolayers (SAMs) of diamondoids are thus of fundamental interest for a variety of emerging applications. This paper presents the effects of thiol substitution position and polymantane order on diamondoid SAMs on gold using near-edge X-ray absorption fine structure spectroscopy (NEXAFS) and X-ray photoelectron spectroscopy (XPS). A framework to determine both molecular tilt and twist through NEXAFS is presented and reveals highly ordered diamondoid SAMs, with the molecular orientation controlled by the thiol location. C 1s and S 2p binding energies are lower in adamantane thiol than alkane thiols on gold by 0.67 {+-} 0.05 eV and 0.16 {+-} 0.04 eV respectively. These binding energies vary with diamondoid monolayer structure and thiol substitution position, consistent with different amounts of steric strain and electronic interaction with the substrate. This work demonstrates control over the assembly, in particular the orientational and electronic structure, providing a flexible design of surface properties with this exciting new class of diamond clusters.

  7. A new spectrometer design for the x-ray spectroscopy of laser-produced

    Office of Scientific and Technical Information (OSTI)

    plasmas with high (sub-ns) time resolution (Journal Article) | SciTech Connect A new spectrometer design for the x-ray spectroscopy of laser-produced plasmas with high (sub-ns) time resolution Citation Details In-Document Search Title: A new spectrometer design for the x-ray spectroscopy of laser-produced plasmas with high (sub-ns) time resolution 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

  8. X-ray line polarization spectroscopy of Li-like satellite line...

    Office of Scientific and Technical Information (OSTI)

    spectroscopy of Li-like satellite line spectra Citation Details In-Document Search Title: X-ray line polarization spectroscopy of Li-like satellite line spectra We apply the ...

  9. Johann Spectrometer for High Resolution X-ray Spectroscopy

    SciTech Connect (OSTI)

    Machek, Pavel; Froeba, Michael; Welter, Edmund; Caliebe, Wolfgang; Brueggmann, Ulf; Draeger, Guenter

    2007-01-19

    A newly designed vacuum Johann spectrometer with a large focusing analyzer crystal for inelastic x-ray scattering and high resolution fluorescence spectroscopy has been installed at the DORIS III storage ring. Spherically bent crystals with a maximum diameter of 125 mm, and cylindrically bent crystals are employed as dispersive optical elements. Standard radius of curvature of the crystals is 1000 mm, however, the design of the mechanical components also facilitates measurements with smaller and larger bending radii. Up to four crystals are mounted on a revolving crystal changer which enables crystal changes without breaking the vacuum. The spectrometer works at fixed Bragg angle. It is preferably designed for the measurements in non-scanning mode with a broad beam spot, and offers a large flexibility to set the sample to the optimum position inside the Rowland circle. A deep depletion CCD camera is employed as a position sensitive detector to collect the energy-analyzed photons on the circumference of the Rowland circle. The vacuum in the spectrometer tank is typically 10-6 mbar. The sample chamber is separated from the tank either by 25 {mu}m thick Kapton windows, which allows samples to be measured under ambient conditions, or by two gate valves. The spectrometer is currently installed at wiggler beamline W1 whose working range is 4-10.5 keV with typical flux at the sample of 5x1010photons/s/mm2. The capabilities of the spectrometer are illustrated by resonant inelastic experiments on 3d transition metals and rare earth compounds, and by chemical shift measurements on chromium compounds.

  10. Low-dimensional systems investigated by x-ray absorption spectroscopy...

    Office of Scientific and Technical Information (OSTI)

    Title: Low-dimensional systems investigated by x-ray absorption spectroscopy: a selection of 2D, 1D and 0D cases Authors: Mino, Lorenzo ; Agostini, Giovanni ; Borfecchia, Elisa ; ...

  11. X-Ray Spectroscopy of the Mn(4) Ca Cluster in the Water-Oxidation...

    Office of Scientific and Technical Information (OSTI)

    Ca Cluster in the Water-Oxidation Complex of Photosystem II Citation Details In-Document Search Title: X-Ray Spectroscopy of the Mn(4) Ca Cluster in the Water-Oxidation Complex ...

  12. Hubbard model corrections in real-space x-ray spectroscopy theory (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Hubbard model corrections in real-space x-ray spectroscopy theory Citation Details In-Document Search Title: Hubbard model corrections in real-space x-ray spectroscopy theory Authors: Ahmed, Towfiq ; Kas, J. J. ; Rehr, J. J. Publication Date: 2012-04-16 OSTI Identifier: 1098737 Type: Publisher's Accepted Manuscript Journal Name: Physical Review B Additional Journal Information: Journal Volume: 85; Journal Issue: 16; Journal ID: ISSN 1098-0121 Publisher: American

  13. X-ray absorption fine-structure spectroscopy (Book) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    X-ray absorption fine-structure spectroscopy Citation Details In-Document Search Title: X-ray absorption fine-structure spectroscopy Authors: Newville, M. [1] + Show Author Affiliations (UC) Publication Date: 2014-12-22 OSTI Identifier: 1168410 Resource Type: Book Resource Relation: Related Information: CMS Workshop Lectures, Advanced Applications of Synchrotron Radiation in Clay Science Publisher: 2014; Tha Clay Minerals Society ;Urbana, IL ;Joseph W. Stucki and Glenn Waychunas, eds.;167-

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

    SciTech Connect (OSTI)

    Greaves, E. D.; Barros, H.; Bermudez, J.; Sajo-Bohus, L.; Angeli-Greaves, M.

    2007-10-26

    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.

  15. The X-ray correlation spectroscopy instrument at the Linac Coherent Light Source

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

    Alonso-Mori, Roberto; Caronna, Chiara; Chollet, Matthieu; Curtis, Robin; Damiani, Daniel S.; Defever, Jim; Feng, Yiping; Flath, Daniel L.; Glownia, James M.; Lee, Sooheyong; et al

    2015-03-03

    The X-ray Correlation Spectroscopy instrument is dedicated to the study of dynamics in condensed matter systems using the unique coherence properties of free-electron lasers. It covers a photon energy range of 4–25 keV. The intrinsic temporal characteristics of the Linac Coherent Light Source, in particular the 120 Hz repetition rate, allow for the investigation of slow dynamics (milliseconds) by means of X-ray photon correlation spectroscopy. Double-pulse schemes could probe dynamics on the picosecond timescale. In addition, a description of the instrument capabilities and recent achievements is presented.

  16. X-Ray Spectroscopy of the Mn(4) Ca Cluster in the Water-Oxidation Complex

    Office of Scientific and Technical Information (OSTI)

    of Photosystem II (Journal Article) | SciTech Connect X-Ray Spectroscopy of the Mn(4) Ca Cluster in the Water-Oxidation Complex of Photosystem II Citation Details In-Document Search Title: X-Ray Spectroscopy of the Mn(4) Ca Cluster in the Water-Oxidation Complex of Photosystem II No abstract prepared. Authors: Sauer, K. ; Yano, J. ; Yachandra, V.K. ; /UC, Berkeley /LBL, Berkeley Publication Date: 2007-08-08 OSTI Identifier: 912555 Report Number(s): SLAC-REPRINT-2005-323 TRN: US200801%%922

  17. X-ray line polarization spectroscopy of Li-like satellite line spectra

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Journal Article: X-ray line polarization spectroscopy of Li-like satellite line spectra Citation Details In-Document Search Title: X-ray line polarization spectroscopy of Li-like satellite line spectra We apply the magnetic-sublevel atomic kinetics model POLAR to the calculation of polarization properties of satellite lines in Li-like Si driven by subpicosecond-duration laser pulses. We identify spectral lines whose polarization can serve as a marker of

  18. High-order multilayer coated blazed gratings for high resolution soft x-ray spectroscopy

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

    Voronov, Dmitriy L.; Goray, Leonid I.; Warwick, Tony; Yashchuk, Valeriy V.; Padmore, Howard A.

    2015-02-17

    A grand challenge in soft x-ray spectroscopy is to drive the resolving power of monochromators and spectrometers from the 104 achieved routinely today to well above 105. This need is driven mainly by the requirements of a new technique that is set to have enormous impact in condensed matter physics, Resonant Inelastic X-ray Scattering (RIXS). Unlike x-ray absorption spectroscopy, RIXS is not limited by an energy resolution dictated by the core-hole lifetime in the excitation process. Using much higher resolving power than used for normal x-ray absorption spectroscopy enables access to the energy scale of soft excitations in matter. Thesemoreexcitations such as magnons and phonons drive the collective phenomena seen in correlated electronic materials such as high temperature superconductors. RIXS opens a new path to study these excitations at a level of detail not formerly possible. However, as the process involves resonant excitation at an energy of around 1 keV, and the energy scale of the excitations one would like to see are at the meV level, to fully utilize the technique requires the development of monochromators and spectrometers with one to two orders of magnitude higher energy resolution than has been conventionally possible. Here we investigate the detailed diffraction characteristics of multilayer blazed gratings. These elements offer potentially revolutionary performance as the dispersive element in ultra-high resolution x-ray spectroscopy. In doing so, we have established a roadmap for the complete optimization of the grating design. Traditionally 1st order gratings are used in the soft x-ray region, but we show that as in the optical domain, one can work in very high spectral orders and thus dramatically improve resolution without significant loss in efficiency.less

  19. High-Resolution Structure of the Photosynthetic Mn4Ca Catalyst from X-ray Spectroscopy

    SciTech Connect (OSTI)

    Yachandra, Vittal; Yano, Junko; Kern, Jan; Pushkar, Yulia; Sauer, Kenneth; Glatzel, Pieter; Bergmann, Uwe; Messinger, Johannes; Zouni, Athina; Yachandra, Vittal K.

    2007-08-01

    The application of high-resolution X-ray spectroscopy methods to study the photosynthetic water oxidizing complex, which contains a unique hetero-nuclear catalytic Mn4Ca cluster, are described. Issues of X-ray damage especially at the metal sites in the Mn4Ca cluster are discussed. The structure of the Mn4Ca catalyst at high-resolution which has so far eluded attempts of determination by X-ray diffraction, EXAFS and other spectroscopic techniques has been addressed using polarized EXAFS techniques applied to oriented PS II membrane preparations and PS II single crystals. A review of how the resolution of traditional EXAFS techniques can be improved, using methods such as range-extended EXAFS is presented, and the changes that occur in the structure of the cluster as it advances through the catalytic cycle are described. X-ray absorption and emission techniques (XANES and K? emission) have been used earlier to determine the oxidation states of the Mn4Ca cluster, and in this report we review the use of X-ray resonant Raman spectroscopy to understand the electronic structure of the Mn4Ca cluster as it cycles through the intermediate S-states.

  20. Passive Spectroscopy Bolometers, Grating- And X-Ray Imaging Crystal Spectrometers

    SciTech Connect (OSTI)

    Bitter, M; Hill, K W; Scott, S; Paul, S; Ince-Cushmann, A; Reinke, M; Rice, J; Beiersdorfer, P; Gu, M F; Lee, S G; Broennimann, C; Eikenberry, E F

    2007-11-07

    This tutorial gives a brief introduction into passive spectroscopy and describes the working principles of bolometers, a high-resolution grating spectrometer, and a novel X-ray imaging crystal spectrometer, which is of particular interest for profile measurements of the ion temperature and plasma rotation velocity on ITER and future burning plasma experiments.

  1. Anion photoelectron spectroscopy of radicals and clusters

    SciTech Connect (OSTI)

    Travis, Taylor R.

    1999-12-16

    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.

  2. In Situ Diffuse Reflectance IR Spectroscopy and X-ray Absorption Spectroscopy for Fast Catalytic Processes

    SciTech Connect (OSTI)

    N Marinkovic; Q Wang; A Frenkel

    2011-12-31

    A new instrument for synchronous in situ investigations of catalytic materials by IR and X-ray absorption spectroscopies was designed and built at the X18A beamline of the National Synchrotron Light Source of Brookhaven National Laboratory. It provides analytical tools for solving structural, electronic and kinetic problems in catalysis science by two complementary methods. Among the features attractive for catalysis research are the broad range of catalytically active elements that can be investigated (starting with Ni and beyond), the wide range of reaction conditions (temperatures up to 873 K, various reactive gases) and time scales (starting from tens of seconds). The results of several representative experiments that illustrate the attractive capabilities of the new set-up are discussed.

  3. Sequential single shot X-ray photon correlation spectroscopy at the SACLA free electron laser

    SciTech Connect (OSTI)

    Lehmkühler, Felix; Kwaśniewski, Paweł; Roseker, Wojciech; Fischer, Birgit; Schroer, Martin A.; Tono, Kensuke; Katayama, Tetsuo; Sprung, Michael; Sikorski, Marcin; Song, Sanghoon; Glownia, James; Chollet, Matthieu; Nelson, Silke; Robert, Aymeric; Gutt, Christian; Yabashi, Makina; Ishikawa, Tetsuya; Grübel, Gerhard

    2015-11-27

    In this study, hard X-ray free electron lasers allow for the first time to access dynamics of condensed matter samples ranging from femtoseconds to several hundred seconds. In particular, the exceptional large transverse coherence of the X-ray pulses and the high time-averaged flux promises to reach time and length scales that have not been accessible up to now with storage ring based sources. However, due to the fluctuations originating from the stochastic nature of the self-amplified spontaneous emission (SASE) process the application of well established techniques such as X-ray photon correlation spectroscopy (XPCS) is challenging. Here we demonstrate a single-shot based sequential XPCS study on a colloidal suspension with a relaxation time comparable to the SACLA free-electron laser pulse repetition rate. High quality correlation functions could be extracted without any indications for sample damage. This opens the way for systematic sequential XPCS experiments at FEL sources.

  4. 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)

    2010-12-01

    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.

  5. X ray photoelectron analysis of oxide-semiconductor interface after breakdown in Al{sub 2}O{sub 3}/InGaAs stacks

    SciTech Connect (OSTI)

    Shekhter, P.; Palumbo, F.; Cohen Weinfeld, K.; Eizenberg, M.

    2014-09-08

    In this work, the post-breakdown characteristics of metal gate/Al{sub 2}O{sub 3}/InGaAs structures were studied using surface analysis by x ray photoelectron spectroscopy. The results show that for dielectric breakdown under positive bias, localized filaments consisting of oxidized substrate atoms (In, Ga and As) were formed, while following breakdown under negative bias, a decrease of oxidized substrate atoms was observed. Such differences in the microstructure at the oxide-semiconductor interface after breakdown for positive and negative voltages are explained by atomic diffusion of the contact atoms into the gate dielectric in the region of the breakdown spot by the current induced electro-migration effect. These findings show a major difference between Al{sub 2}O{sub 3}/InGaAs and SiO{sub 2}/Si interfaces, opening the way to a better understanding of the breakdown characteristics of III-V complementary-metal-oxide-semiconductor technology.

  6. 15.05.29 RH Operando X-ray - JCAP

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

    Direct Observation of a Semiconductor/Liquid Junction by Operando X-Ray Photoelectron Spectroscopy (XPS) Lichterman , M. F. et al. Direct Observation of the Energetics at a Semiconductor/Liquid Junction by Operando X-Ray Photoelectron Spectroscopy. Energy Environ. Sci ., 2015, DOI: 10.1039/C5EE01014D (2015). Scientific Achievement We demonstrated that the operando XPS technique, applied to a semiconductor/liquid junction, can directly measure the positions of the electronic states of the

  7. Characterization of Gas Shales by X-ray Raman Spectroscopy | Stanford

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

    Synchrotron Radiation Lightsource Characterization of Gas Shales by X-ray Raman Spectroscopy Thursday, February 23, 2012 - 10:30am SSRL Third Floor Conference Room 137-322 Drew Pomerantz, Schlumberger Unconventional hydrocarbon resources such as gas shale and oil-bearing shale have emerged recently as economically viable sources of energy, dramatically altering America's energy landscape. Despite their importance, the basic chemistry and physics of shales are not understood as well as

  8. Characterization of Gas Shales by X-ray Raman Spectroscopy | Stanford

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

    Synchrotron Radiation Lightsource Characterization of Gas Shales by X-ray Raman Spectroscopy Monday, May 14, 2012 - 3:30pm SSRL Conference Room 137-322 Drew Pomerantz, Schlumberger Unconventional hydrocarbon resources such as gas shale and oil-bearing shale have emerged recently as economically viable sources of energy, dramatically altering America's energy landscape. Despite their importance, the basic chemistry and physics of shales are not understood as well as conventional reservoirs.

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

    SciTech Connect (OSTI)

    Paesler, M.; Sayers, D.

    1988-12-01

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

  10. Two Novel x-ray Optical Schemes for Spectroscopy with Fast Time Resolution

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

    and Two-dimensional Imaging with High Magnification ---- Inventor(s) Manfred Bitter, Kenneth W. Hill, Luis Delgado-Apricio, Novimir Pablant, Steve Scott and Frank Jones | Princeton Plasma Physics Lab Two Novel x-ray Optical Schemes for Spectroscopy with Fast Time Resolution and Two-dimensional Imaging with High Magnification ---- Inventor(s) Manfred Bitter, Kenneth W. Hill, Luis Delgado-Apricio, Novimir Pablant, Steve Scott and Frank Jones This Invention describes two optical schemes, which

  11. Vertical dispersion methods in x-ray spectroscopy of high temperature plasmas

    SciTech Connect (OSTI)

    Renner, O.; Missalla, T.; Foerster, E.

    1995-12-31

    General formulae for the applying the vertical dispersion principle in x-ray spectroscopy of multiple charged ions are summarized, the characteristics of the experimental schemes based on flat and bent crystals are discussed. The unique properties of the novel spectroscopic methods, i.e., their extremely high dispersion, high spectral and 1-D spatial resolution and good collection efficiency, make them very attractive for ultrahigh-resolution spectroscopy. The examples of successful use of the vertical dispersion modifications of the double-crystal and the Johann spectrometer in diagnostics of several types of laser-generated plasma are presented.

  12. Note: Sample chamber for in situ x-ray absorption spectroscopy studies of battery materials

    SciTech Connect (OSTI)

    Pelliccione, CJ; Timofeeva, EV; Katsoudas, JP; Segre, CU

    2014-12-01

    In situ x-ray absorption spectroscopy (XAS) provides element-specific characterization of both crystalline and amorphous phases and enables direct correlations between electrochemical performance and structural characteristics of cathode and anode materials. In situ XAS measurements are very demanding to the design of the experimental setup. We have developed a sample chamber that provides electrical connectivity and inert atmosphere for operating electrochemical cells and also accounts for x-ray interactions with the chamber and cell materials. The design of the sample chamber for in situ measurements is presented along with example XAS spectra from anode materials in operating pouch cells at the Zn and Sn K-edges measured in fluorescence and transmission modes, respectively. (C) 2014 AIP Publishing LLC.

  13. Sequential single shot X-ray photon correlation spectroscopy at the SACLA free electron laser

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

    Lehmkühler, Felix; Kwaśniewski, Paweł; Roseker, Wojciech; Fischer, Birgit; Schroer, Martin A.; Tono, Kensuke; Katayama, Tetsuo; Sprung, Michael; Sikorski, Marcin; Song, Sanghoon; et al

    2015-11-27

    In this study, hard X-ray free electron lasers allow for the first time to access dynamics of condensed matter samples ranging from femtoseconds to several hundred seconds. In particular, the exceptional large transverse coherence of the X-ray pulses and the high time-averaged flux promises to reach time and length scales that have not been accessible up to now with storage ring based sources. However, due to the fluctuations originating from the stochastic nature of the self-amplified spontaneous emission (SASE) process the application of well established techniques such as X-ray photon correlation spectroscopy (XPCS) is challenging. Here we demonstrate a single-shotmore » based sequential XPCS study on a colloidal suspension with a relaxation time comparable to the SACLA free-electron laser pulse repetition rate. High quality correlation functions could be extracted without any indications for sample damage. This opens the way for systematic sequential XPCS experiments at FEL sources.« less

  14. 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)

    2012-03-13

    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.

  15. Report on the Feasibility of Pu Photoelectron Spectroscopy with...

    Office of Scientific and Technical Information (OSTI)

    Report on the Feasibility of Pu Photoelectron Spectroscopy with Microscopic and Nanoscopic Samples at NSLSII Citation Details In-Document Search Title: Report on the Feasibility of ...

  16. Photoelectron spectroscopy of wet and gaseous samples through graphene membranes

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

    Kraus, Jürgen; Reichelt, Robert; Günther, Sebastian; Gregoratti, Luca; Amati, Matteo; Kiskinova, Maya; Yulaev, Alexander; Vlassiouk, Ivan V.; Kolmakov, Andrei

    2014-01-01

    Photoelectron spectroscopy (PES) and microscopy are highly important for exploring morphologically and chemically complex liquid–gas, solid–liquid and solid–gas interfaces under realistic conditions, but the very small electron mean free path inside dense media imposes serious experimental challenges. Currently, near ambient pressure PES is conducted using dexterously designed electron energy analyzers coupled with differentially pumped electron lenses which make it possible to conduct PES measurements at a few hPa. This report proposes an alternative ambient pressure approach that can be applied to a broad class of samples and be implemented in conventional PES instruments. It uses ultrathin electron transparent but molecularmore » impermeable membranes to isolate the high pressure sample environment from the high vacuum PES detection system. We show that the separating graphene membrane windows are both mechanically robust and sufficiently transparent for electrons in a wide energy range to allow soft X-ray PES of liquid and gaseous water. The performed proof-of-principle experiments confirm the possibility to probe vacuum-incompatible toxic or reactive samples placed inside such hermetic, gas flow or fluidic environmental cells.« less

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

    SciTech Connect (OSTI)

    Hernndez, Rebeca, E-mail: rhernandez@ictp.csic.es, E-mail: aurora.nogales@csic.es; Mijangos, Carmen [Instituto de Ciencia y Tecnologa de Polmeros, ICTP-CSIC, Juan de la Cierva, 3, 28006 Madrid (Spain)] [Instituto de Ciencia y Tecnologa de Polmeros, 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)

    2014-01-14

    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.

  18. High-Resolution Spectroscopy with the Chandra X-ray Observatory

    ScienceCinema (OSTI)

    Canizares, Claude R. [MIT, Cambridge, Massachusetts, United States

    2010-01-08

    The capabilities of the Chandra X-ray Observatory and XMM-Newton for high-resolution spectroscopy have brought tradition plasma diagnostic techniques to the study of cosmic plasma. Observations have probed nearly every class of astronomical object, from young proto-starts through massive O starts and black hole binaries, supernova remnants, active galactic nuclei, and the intergalactic medium. Many of these sources show remarkable rich spectra that reveal new physical information, such as emission measure distributions, elemental abundances, accretion disk and wind signatures, and time variability. This talk will present an overview of the Chandra instrumentaton and selected examples of spectral observations of astrophysical and cosmological importance.

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

    SciTech Connect (OSTI)

    Balasubramanian, M.

    1998-06-02

    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.

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

    SciTech Connect (OSTI)

    Powell, Cedric J.; Werner, Wolfgang S. M.; Smekal, Werner

    2014-09-01

    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.

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

    SciTech Connect (OSTI)

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

    2013-06-01

    Plutonium uranium mixed oxide (MOX) fuels are currently used in nuclear reactors. The actinides in these fuels need to be analyzed after irradiation for assessing their behaviour with regard to their environment and the coolant. In this work the study of the atomic structure and next-neighbour environment of Am in the (Pu,U)O? lattice in an irradiated (60 MW d kg?) MOX sample was performed employing micro-X-ray fluorescence (-XRF) and micro-X-ray absorption fine structure (-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 Am? species within an [AmO?]? 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 ?m300 ?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 Am? face an AmO??coordination environment in the (Pu,U)O? matrix. The americium dioxide is reduced by the uranium dioxide matrix.

  2. Bimolecular reaction dynamics from photoelectron spectroscopy of negative ions

    SciTech Connect (OSTI)

    Bradforth, S.E.

    1992-11-01

    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. 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

    2012-11-21

    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.

  4. Photon-in photon-out hard X-ray spectroscopy at the Linac Coherent...

    Office of Scientific and Technical Information (OSTI)

    different source characteristics and its resulting impact on sample delivery, X-ray optics, X-ray detection and data acquisition. Here it is described how photon-in photon-out...

  5. Design of Molecular Solar Cells via Feedback from Soft X-ray Spectroscopy

    SciTech Connect (OSTI)

    Himpsel, Franz J.

    2015-06-12

    Spectroscopy with soft X-rays was used to develop new materials and novel designs for solar cells and artificial photosynthesis. In order to go beyond the widely-used trial-and-error approach of gradually improving a particular design, we started from the most general layout of a solar cell (or a photo-electrochemical device) and asked which classes of materials are promising for best performance. For example, the most general design of a solar cell consists of a light absorber, an electron donor, and an electron acceptor. These are characterized by four energy levels, which were measured by a combination of spectroscopic X-ray techniques. Tuning synchrotron radiation to the absorption edges of specific elements provided element- and bond-selectivity. The spectroscopic results were complemented by state-of-the-art calculations of the electronic states. These helped explaining the observed energy levels and the orbitals associated with them. The calculations were extended to a large class of materials (for example thousands of porphyrin dye complexes) in order to survey trends in the energy level structure. A few highlights serve as examples: 1) Organic molecules combining absorber, donor, and acceptor with atomic precision. 2) Exploration of highly p-doped diamond films as inert, transparent electron donors. 3) Surface-sensitive characterization of nanorod arrays used as photoanodes in water splitting. 4) Computational design of molecular complexes for efficient solar cells using two photons.

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

    SciTech Connect (OSTI)

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

    1995-03-01

    Construction and performance of a monolithic quad-pixel Ge detector for fluorescence x-ray absorption spectroscopy (XAS) at synchrotron radiation sources are described. The detector semiconductor element has an active surface area of 4.0 cm{sup 2} which is electrically separated into four 1.0 cm{sup 2} pixels, with little interfacial dead volume. Spatial response of the array shows that cross-talk between adjacent pixels is < 10% for 5.9 keV photons that fall within 0.5 mm of the pixel boundaries. The detector electronics system uses pre-amplifiers built at LBNL with commercial Tennelec Model TC 244 amplifiers. Using an {sup 55}Fe test source (MnK{sub {alpha}}, 5.9 keV), energy resolution of better than 200 eV is achieved with a 4 {mu}sec peaking time. At 0.5 {mu}sec peaking time, pulse pileup results in a 75% throughput efficiency for an incoming count rate of 100 kHz. Initial XAS fluoresncece measurements at the beamline 4 wiggler end stations at SSRL show that the detector system has several advantages over commercial x-ray spectrometers for low-concentration counting.

  7. 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

    2007-05-07

    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.

  8. X-ray Absorption Spectroscopy Beamline at the Siam Photon Laboratory

    SciTech Connect (OSTI)

    Klysubun, Wantana; Tarawarakarn, Pongjakr; Sombunchoo, Panidtha; Klinkhieo, Supat; Chaiprapa, Jitrin; Songsiriritthigul, Prayoon

    2007-01-19

    A bending magnet beamline has been constructed and commissioned for x-ray absorption spectroscopy (XAS) at the Siam Photon Laboratory. The photon energy is tunable from 1830 eV to 8000 eV using a Lemmonier-type, fixed-exit double crystal monochromator equipped with InSb(111), Si(111), Ge(220) crystals. Elemental K-edges are then accessible from silicon to iron. A series of low conductance vacuum tubes has been designed and installed between the pumping chambers in the front end to obtain the proper pressure difference between the upstream and the downstream of the front end. Thus lower-energy photons, around K-edges of silicon, phosphorous, and sulfur, can be delivered to the experimental XAS station without being absorbed by a window. In this report, the design of the beamline is described. The commissioning results including the measured photon flux at sample and experimental XAS spectra are presented.

  9. Zero kinetic energy photoelectron spectroscopy of triphenylene

    SciTech Connect (OSTI)

    Harthcock, Colin; Zhang, Jie; Kong, Wei

    2014-06-28

    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.

  10. Local electronic states of Fe{sub 4}N films revealed by x-ray absorption spectroscopy and x-ray magnetic circular dichroism

    SciTech Connect (OSTI)

    Ito, Keita; Toko, Kaoru; Suemasu, Takashi; Takeda, Yukiharu; Saitoh, Yuji; Oguchi, Tamio; Kimura, Akio

    2015-05-21

    We performed x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) measurements at Fe L{sub 2,3} and N K-edges for Fe{sub 4}N epitaxial films grown by molecular beam epitaxy. In order to clarify the element specific local electronic structure of Fe{sub 4}N, we compared experimentally obtained XAS and XMCD spectra with those simulated by a combination of a first-principles calculation and Fermi's golden rule. We revealed that the shoulders observed at Fe L{sub 2,3}-edges in the XAS and XMCD spectra were due to the electric dipole transition from the Fe 2p core-level to the hybridization state generated by ?* anti-bonding between the orbitals of N 2p at the body-centered site and Fe 3d on the face-centered (II) sites. Thus, the observed shoulders were attributed to the local electronic structure of Fe atoms at II sites. As to the N K-edge, the line shape of the obtained spectra was explained by the dipole transition from the N 1s core-level to the hybridization state formed by ?* and ?* anti-bondings between the Fe 3d and N 2p orbitals. This hybridization plays an important role in featuring the electronic structures and physical properties of Fe{sub 4}N.

  11. Report on the Feasibility of Pu Photoelectron Spectroscopy with Microscopic

    Office of Scientific and Technical Information (OSTI)

    and Nanoscopic Samples at NSLSII (Technical Report) | SciTech Connect Report on the Feasibility of Pu Photoelectron Spectroscopy with Microscopic and Nanoscopic Samples at NSLSII Citation Details In-Document Search Title: Report on the Feasibility of Pu Photoelectron Spectroscopy with Microscopic and Nanoscopic Samples at NSLSII Authors: Tobin, J G Publication Date: 2012-09-11 OSTI Identifier: 1053685 Report Number(s): LLNL-TR-582213 DOE Contract Number: W-7405-ENG-48 Resource Type:

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

    SciTech Connect (OSTI)

    DeWitt, Curtis; Bandyopadhyay, Reba M.; Eikenberry, Stephen S.; Sarajedini, Ata; Sellgren, Kris; Blum, Robert; Olsen, Knut; Bauer, Franz E.

    2013-11-01

    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.

  13. Bimolecular reaction dynamics from photoelectron spectroscopy of negative ions

    SciTech Connect (OSTI)

    Bradforth, S.E.

    1992-11-01

    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.

  14. Photon-in photon-out hard X-ray spectroscopy at the Linac Coherent Light Source

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

    Alonso-Mori, Roberto; Sokaras, Dimosthenis; Zhu, Diling; Kroll, Thomas; Chollet, Mathieu; Feng, Yiping; Glownia, James M.; Kern, Jan; Lemke, Henrik T.; Nordlund, Dennis; et al

    2015-04-15

    X-ray free-electron lasers (FELs) have opened unprecedented possibilities to study the structure and dynamics of matter at an atomic level and ultra-fast timescale. Many of the techniques routinely used at storage ring facilities are being adapted for experiments conducted at FELs. In order to take full advantage of these new sources several challenges have to be overcome. They are related to the very different source characteristics and its resulting impact on sample delivery, X-ray optics, X-ray detection and data acquisition. Here it is described how photon-in photon-out hard X-ray spectroscopy techniques can be applied to study the electronic structure andmore » its dynamics of transition metal systems with ultra-bright and ultra-short FEL X-ray pulses. In particular, some of the experimental details that are different compared with synchrotron-based setups are discussed and illustrated by recent measurements performed at the Linac Coherent Light Source.« less

  15. X-ray Absorption Spectroscopy Characterization of a Li/S Cell

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

    Ye, Yifan; Kawase, Ayako; Song, Min-Kyu; Feng, Bingmei; Liu, Yi-Sheng; Marcus, Matthew A.; Feng, Jun; Cairns, Elton J.; Guo, Jinghua; Zhu, Junfa

    2016-01-11

    The X-ray absorption spectroscopy technique has been applied to study different stages of the lithium/sulfur (Li/S) cell life cycle. We investigated how speciation of S in Li/S cathodes changes upon the introduction of CTAB (cetyltrimethylammonium bromide, CH3(CH2)15N+(CH3)3Br₋) and with charge/discharge cycling. The introduction of CTAB changes the synthesis reaction pathway dramatically due to the interaction of CTAB with the terminal S atoms of the polysulfide ions in the Na2Sx solution. For the cycled Li/S cell, the loss of electrochemically active sulfur and the accumulation of a compact blocking insulating layer of unexpected sulfur reaction products on the cathode surface duringmore » the charge/discharge processes make the capacity decay. Lastly, a modified coin cell and a vacuum-compatible three-electrode electro-chemical cell have been introduced for further in-situ/in-operando studies.« less

  16. The X-ray correlation spectroscopy instrument at the Linac Coherent...

    Office of Scientific and Technical Information (OSTI)

    characteristics of the Linac Coherent Light Source, in particular the 120 Hz repetition rate, allow for the investigation of slow dynamics (milliseconds) by means of X-ray photon...

  17. Low-level determination of plutonium by gamma and L x-ray spectroscopy

    SciTech Connect (OSTI)

    Nitsche, H.; Gatti, R.C.; Lee, S.C.

    1991-04-01

    we have developed an analytical method for detection of {sup 239}Pu in aqueous samples at concentrations as low as 10{sup {minus}10} M. This nuclear counting technique utilizes the uranium L X-rays, which follow the alpha decay of plutonium. Because L X-rays are specific for the element and not for the individual isotopes, the isotopic composition of the plutonium sample must be known. The counting efficiency in the 11--23 keV range is determined from a plutonium standard, and the concentration of the sample is then calculated from the L X-ray count and the isotopic composition. The total L X-ray count is corrected for possible contributions from other radionuclides present as impurities by measuring the low-energy gamma spectrum for each contaminant to establish specific photon/X-ray ratios. The ratios are important when {sup 241}Pu and {sup 242}Pu are measured, because the respective decay chain members produce non-U L X-rays. This new method can replace the use of labor-intensive radiochemical separation techniques and elaborate activation methods for analysis of {sup 239}Pu in aqueous samples. It is also applicable for assaying plutonium in liquid wastes that pose possible hazards to the environment.

  18. Sample-morphology effects on x-ray photoelectron peak intensities. III. Simulated spectra of model core–shell nanoparticles

    SciTech Connect (OSTI)

    Powell, Cedric J.; Chudzicki, Maksymilian; Werner, Wolfgang S. M.; Smekal, Werner

    2015-09-15

    The National Institute of Standards and Technology database for the simulation of electron spectra for surface analysis has been used to simulate Cu 2p photoelectron spectra for four types of spherical copper–gold nanoparticles (NPs). These simulations were made to extend the work of Tougaard [J. Vac. Sci. Technol. A 14, 1415 (1996)] and of Powell et al. [J. Vac. Sci. Technol. A 31, 021402 (2013)] who performed similar simulations for four types of planar copper–gold films. The Cu 2p spectra for the NPs were compared and contrasted with analogous results for the planar films and the effects of elastic scattering were investigated. The new simulations were made for a monolayer of three types of Cu/Au core–shell NPs on a Si substrate: (1) an Au shell of variable thickness on a Cu core with diameters of 0.5, 1.0, 2.0, 5.0, and 10.0 nm; (2) a Cu shell of variable thickness on an Au core with diameters of 0.5, 1.0, 2.0, 5.0, and 10.0 nm; and (3) an Au shell of variable thickness on a 1 nm Cu shell on an Au core with diameters of 0.5, 1.0, 2.0, 5.0, and 10.0 nm. For these three morphologies, the outer-shell thickness was varied until the Cu 2p{sub 3/2} peak intensity was the same (within 2%) as that found in our previous work with planar Cu/Au morphologies. The authors also performed similar simulations for a monolayer of spherical NPs consisting of a CuAu{sub x} alloy (also on a Si substrate) with diameters of 0.5, 1.0, 2.0, 5.0, and 10.0 nm. In the latter simulations, the relative Au concentration (x) was varied to give the same Cu 2p{sub 3/2} peak intensity (within 2%) as that found previously. For each morphology, the authors performed simulations with elastic scattering switched on and off. The authors found that elastic-scattering effects were generally strong for the Cu-core/Au-shell and weak for the Au-core/Cu-shell NPs; intermediate elastic-scattering effects were found for the Au-core/Cu-shell/Au-shell NPs. The shell thicknesses required to give the selected Cu 2p{sub 3/2} peak intensity for the three types of core–shell NPs were less than the corresponding film thicknesses of planar samples since Cu 2p photoelectrons can be detected from the sides and, for the smaller NPs, bottoms of the NPs. Elastic-scattering effects were also observed on the Au atomic fractions found for the CuAu{sub x} NP alloys with different diameters.

  19. Synchrotron x-ray spectroscopy studies of valence and magnetic state in europium metal to extreme pressures

    SciTech Connect (OSTI)

    Bi, W.; Souza-Neto, N.M.; Haskel, D.; Fabbris, G.; Alp, E.E.; Zhao, J.; Hennig, R.G.; Abd-Elmeguid, M.M.; Meng, Y.; McCallum, Ralph W.; Dennis, Kevin; Schilling, J.S.

    2012-05-22

    In order to probe the changes in the valence state and magnetic properties of Eu metal under extreme pressure, x-ray absorption near-edge spectroscopy, x-ray magnetic circular dichroism, and synchrotron Mössbauer spectroscopy experiments were carried out. The Mössbauer isomer shift exhibits anomalous pressure dependence, passing through a maximum near 20 GPa. Density functional theory has been applied to give insight into the pressure-induced changes in both Eu's electronic structure and Mössbauer isomer shift. Contrary to previous reports, Eu is found to remain nearly divalent to the highest pressures reached (87 GPa) with magnetic order persisting to at least 50 GPa. These results should lead to a better understanding of the nature of the superconducting state found above 75 GPa and of the sequence of structural phase transitions observed to 92 GPa.

  20. Runaway electron energy measurement using hard x-ray spectroscopy in 'Damavand' tokamak

    SciTech Connect (OSTI)

    Rasouli, C.; Farahbod, A. H.; Rasouli, H.; Lamehi, M.; Iraji, D.; Akhtari, K.; Modarresi, H.

    2009-01-15

    Set of experiments has been developed to study existing runaway electrons in ''Damavand'' tokamak plasma upon characteristics of hard x-ray emissions produced by collision of the runaway electrons with the plasma particles and limiters. As a first step, spatial distribution of hard x-ray emissions on the equatorial plane of the torus was considered. Obtained spectra of hard x-ray emissions for different alignments of shielded detector indicate isotropic emissivity in the equatorial plane. This is in agreement with wide angle cone of bremsstrahlung radiations, deduced from the mean value of energy of the runaway electrons. The mean energy was calculated from the slope of the energy spectrum of hard x-ray photons. In the second stage in order to investigate time evolution of energy of the runaway electrons, similar technique were applied to obtain hard x-ray energy in every 3 ms intervals, from the beginning to the end of plasma. The mean energy of the runaway electrons increases during the ramp up phase and reaches its maximum between 3 and 9 ms after plasma formation. Also considering the time dependence of the counted photons in each energy range shows that energetic photons are emitted during the ramp up phase of the plasma current in Damavand tokamak.

  1. Oxidation/Reduction Reactions at the Metal Contact-TlBr Interface: An X-ray

    Office of Scientific and Technical Information (OSTI)

    Photoelectron Spectroscopy Study (Conference) | SciTech Connect Conference: Oxidation/Reduction Reactions at the Metal Contact-TlBr Interface: An X-ray Photoelectron Spectroscopy Study Citation Details In-Document Search Title: Oxidation/Reduction Reactions at the Metal Contact-TlBr Interface: An X-ray Photoelectron Spectroscopy Study Authors: Nelson, A J ; Swanberg, E L ; Voss, L F ; Graff, R T ; Conway, A M ; Nikolic, R J ; Payne, S A ; Kim, H ; Cirignano, L ; Shah, K Publication Date:

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

    Broader source: Energy.gov [DOE]

    Presentation given at DEER 2006, August 20-24, 2006, Detroit, Michigan. Sponsored by the U.S. DOE's EERE FreedomCar and Fuel Partnership and 21st Century Truck Programs.

  3. Observing heme doming in myoglobin with femtosecond X-ray absorption spectroscopy

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

    Levantino, M.; Lemke, H. T.; Schirò, G.; Glownia, M.; Cupane, A.; Cammarata, M.

    2015-07-01

    We report time-resolved X-ray absorption measurements after photolysis of carbonmonoxy myoglobin performed at the LCLS X-ray free electron laser with nearly 100 fs (FWHM) time resolution. Data at the Fe K-edge reveal that the photoinduced structural changes at the heme occur in two steps, with a faster (~70 fs) relaxation preceding a slower (~400 fs) one. We tentatively attribute the first relaxation to a structural rearrangement induced by photolysis involving essentially only the heme chromophore and the second relaxation to a residual Fe motion out of the heme plane that is coupled to the displacement of myoglobin F-helix.

  4. 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

    2014-04-17

    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

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

    SciTech Connect (OSTI)

    Gaudin, J.; Fourment, C.; Cho, B. I.; Engelhorn, K.; Galtier, E.; Harmand, M.; Leguay, P. M.; Lee, H. J.; Nagler, B.; Nakatsutsumi, M.; Ozkan, C.; Strmer, M.; Toleikis, S.; Tschentscher, Th.; Heimann, P. A.; Dorchies, F.

    2014-04-17

    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 of 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.

  6. X-Ray Diffraction > Analytical Resources > Research > The Energy...

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

    Analytical Resources In This Section Differential Electrochemical Mass Spectroscopy (DEMS) Electron Microscopy X-Ray Diffraction X-Ray Diffraction...

  7. Effects of Plant Cell Wall Matrix Polysaccharides on Bacterial Cellulose Structure Studied with Vibrational Sum Frequency Generation Spectroscopy and X-ray Diffraction

    SciTech Connect (OSTI)

    Park, Yong Bum; Lee, Christopher M; Kafle, Kabindra; Park, Sunkyu; Cosgrove, Daniel; Kim, Seong H

    2014-07-14

    The crystallinity, allomorph content, and mesoscale ordering of cellulose produced by Gluconacetobacter xylinus cultured with different plant cell wall matrix polysaccharides were studied with vibrational sum frequency generation (SFG) spectroscopy and X-ray diffraction (XRD).

  8. Investigating inertial confinement fusion target fuel conditions through x-ray spectroscopy

    SciTech Connect (OSTI)

    Hansen, Stephanie B.

    2012-05-15

    Inertial confinement fusion (ICF) targets are designed to produce hot, dense fuel in a neutron-producing core that is surrounded by a shell of compressing material. The x-rays emitted from ICF plasmas can be analyzed to reveal details of the temperatures, densities, gradients, velocities, and mix characteristics of ICF targets. Such diagnostics are critical to understand the target performance and to improve the predictive power of simulation codes.

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

    SciTech Connect (OSTI)

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

    2009-05-24

    We report measurements of the photo-induced Fe(II) spin crossover reaction dynamics in solution via time-resolved x-ray absorption spectroscopy. EXAFS measurements reveal that the iron?nitrogen bond lengthens by 0.21+-0.03 Angstrom in the high-spin transient excited state relative to the ground state. XANES measurements at the Fe L-edge show directly the influence of the structural change on the ligand-field splitting of the Fe(II) 3d orbitals associated with the spin transition.

  10. X-ray Spectroscopy with Elliptical Crystals and Face-On Framing Cameras

    SciTech Connect (OSTI)

    Heeter, R; Emig, J; Fournier, K; Hansen, S; May, M; Young, B

    2004-04-16

    X-ray spectrometers using elliptically bent crystals have desirable properties for applications requiring broad spectral coverage, good spectral resolution, and minimized source broadening. Previous work used custom-positioned film or microchannel plate detectors. They find it is also useful and cost-effective to field elliptical crystals in existing snouts on the face-on gated microchannel plate framing cameras commonly used at many facilities. they numerically explored the full design space (spectral range and resolution) of elliptical crystals compatible with the new MSPEC multipurpose spectrometer snout. They have tested at the Omega laser an elliptical RAP crystal with 174 mm focal length, 0.9885 eccentricity, and 4.6 degree inclination, viewing from 1.0 to at least 1.7 keV with E/dE of 300-500. A slit (2x mag) images 3 mm sources with 70 um spatial resolution.

  11. X-ray spectroscopy with elliptical crystals and face-on framing cameras

    SciTech Connect (OSTI)

    Heeter, R.F.; Emig, J.A.; Fournier, K.B.; Hansen, S.B.; May, M.J.; Young, B.K.F.

    2004-10-01

    X-ray spectrometers using elliptically bent crystals have desirable properties for applications requiring broad spectral coverage, good spectral resolution, and minimized source broadening. Previous work used custom-positioned film or microchannel plate detectors. We find it is also useful and cost-effective to field elliptical crystals in existing snouts on the face-on gated microchannel plate framing cameras commonly used at many facilities. We numerically explored the full design space (spectral range and resolution) of elliptical crystals compatible with the new multipurpose spectrometer snout. We have tested at the Omega laser an elliptical rubidium acid phthalate crystal with 174 mm focal length, 0.9885 eccentricity, and 4.6 deg. inclination, viewing from 1.0 to at least 1.7 keV with spectral resolution E/dE of 300-500. A slit (2xmagnification) images 3 mm sources with 70 {mu}m spatial resolution.

  12. X-ray absorption spectroscopy on the calcium cofactor to the manganese cluster in photosynthetic oxygen evolution

    SciTech Connect (OSTI)

    Cinco, Roehl M.

    1999-12-16

    Along with Mn, calcium and chloride ions are necessary cofactors for oxygen evolution in Photosystem II (PS II). To further test and verify whether Ca is close to the Mn cluster, the authors substituted strontium for Ca and probed from the Sr point of view for any nearby Mn. The extended X-ray absorption fine structure (EXAFS) of Sr-reactivated PS II indicates major differences between the intact and NH{sub 2}OH-treated samples. In intact samples, the Fourier transform of the Sr EXAFS shows a Fourier peak that is missing in inactive samples. This peak II is best simulated by two Mn neighbors at a distance of 3.5 Angstrom, confirming the proximity of Ca (Sr) cofactor to the Mn cluster. In addition, polarized Sr EXAFS on oriented Sr-reactivated samples shows this peak II is dichroic: large magnitude at 10 degrees (angle between the PS II membrane normal and the x-ray electric field vector) and small at 80 degrees. Analysis of the dichroism yields the relative angle between the Sr-Mn vector and membrane normal (23 degrees {+-} 4 degrees), and the isotropic coordination number for these layered samples. X-ray absorption spectroscopy has also been employed to assess the degree of similarity between the manganese cluster in PS II and a family of synthetic manganese complexes containing the distorted cubane [Mn{sub 4}O{sub 3}X] core (X = benzoate, acetate, methoxide, hydroxide, azide, fluoride, chloride or bromide). In addition, Mn{sub 4}O{sub 3}Cl complexes containing three or six terminal Cl ligands at three of the Mn were included in this study. The EXAFS method detects the small changes in the core structures as X is varied in this series, and serves to exclude these distorted cubanes of C3v symmetry as a topological model for the Mn catalytic cluster. The sulfur K-edge x-ray absorption near-edge structure (XANES) spectra for the amino acids cysteine, methionine, their corresponding oxidized forms cystine and methionine sulfoxide, and glutathione show distinct differences between the thiol and disulfide forms. Sulfur XANES is also used to detect changes (within 5%) of the thiol-to-disulfide ratio in whole human blood, plasma, and erythrocytes.

  13. The X-ray correlation spectroscopy instrument at the Linac Coherent...

    Office of Scientific and Technical Information (OSTI)

    spectroscopy. Double-pulse schemes could probe dynamics on the picosecond timescale. In addition, a description of the instrument capabilities and recent achievements is...

  14. 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

    1984-01-01

    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)

  15. Local structure of Fe in Fe-doped misfit-layered calcium cobaltite: An X-ray absorption spectroscopy study

    SciTech Connect (OSTI)

    Prasoetsopha, Natkrita; Pinitsoontorn, Supree; Bootchanont, Atipong; Kidkhunthod, Pinit; Srepusharawoot, Pornjuk; Kamwanna, Teerasak; Amornkitbamrung, Vittaya; Kurosaki, Ken; Yamanaka, Shinsuke

    2013-08-15

    Polycrystalline Ca{sub 3}Co{sub 4?x}Fe{sub x}O{sub 9+?} ceramics (x=0, 0.01, 0.03, 0.05) were fabricated using a simple thermal hydro-decomposition method and a spark plasma sintering technique. Thermoelectric property measurements showed that increasing Fe concentration resulted in a decrease in electrical resistivity, thermopower and thermal conductivity, leading to an improvement in the dimensionless figure-of-merit, >35% for x=0.05 at 1073 K. An X-ray absorption spectroscopy technique was used to investigate the local structure of Fe ions in the Ca{sub 3}Co{sub 4?x}Fe{sub x}O{sub 9+?} structure for the first time. By fitting data from the extended X-ray absorption fine structure (EXAFS) spectra and analyzing the X-ray absorption near-edge structure (XANES) spectra incorporated with first principle simulation, it was shown that Fe was substituted for Co in the the Ca{sub 2}CoO{sub 3} (rocksalt, RS) layer rather than in the CoO{sub 2} layer. Variation in the thermoelectric properties as a function of Fe concentration was attributed to charge transfer between the CoO{sub 2} and the RS layers. The origin of the preferential Fe substitution site was investigated considering the ionic radii of Co and Fe and the total energy of the system. - Graphical abstract: The Fe K-edge XANES spectra of: (a) experimental result in comparison to the simulated spectra when Fe atoms were substituted in the RS layer; (b) with magnetic moment; (c) without magnetic moment, and in the CoO{sub 2} layer; (d) with magnetic moment and (e) without magnetic moment. Highlights: Synthesis, structural studies, and thermoelectric properties of Ca{sub 3}Co{sub 4?x}Fe{sub x}O{sub 9+?}. Direct evidence for the local structure of the Fe ions in the Ca{sub 3}Co{sub 4?x}Fe{sub x}O{sub 9+?} using XAS analysis. EXAFS and XANES analysis showed that Fe was likely to be situated in the RS layer structure. Changes in TE property with Fe content was due to charge transfer between the CoO{sub 2} and the RS layers. Total energy calculation showed energetically favorable Fe substitution in the RS layer.

  16. Determining Orientational Structure of Diamondoid Thiols Attached to Silver Using Near Edge X-ray Absorption Fine Structure Spectroscopy

    SciTech Connect (OSTI)

    Willey, T M; Lee, J I; Fabbri, J D; Wang, D; Nielsen, M; Randel, J C; Schreiner, P R; Fokin, A A; Tkachenko, B A; Fokina, N A; Dahl, J P; Carlson, R K; Terminello, L J; Melosh, N A; van Buuren, T

    2008-10-07

    Near-edge x-ray absorption fine structure spectroscopy (NEXAFS) is a powerful tool for determination of molecular orientation in self-assembled monolayers and other surface-attached molecules. A general framework for using NEXAFS to simultaneously determine molecular tilt and twist of rigid molecules attached to surfaces is presented. This framework is applied to self-assembled monolayers of higher diamondoid, hydrocarbon molecules with cubic-diamond-cage structures. Diamondoid monolayers chemisorbed on metal substrates are known to exhibit interesting electronic and surface properties. This work compares molecular orientation in monolayers prepared on silver substrates using two different thiol positional isomers of [121]tetramantane, and thiols derived from two different pentamantane structural isomers, [1212]pentamantane and [1(2,3)4]pentamantane. The observed differences in monolayer structure demonstrate the utility and limitations of NEXAFS spectroscopy and the framework. The results also demonstrate the ability to control diamondoid assembly, in particular the molecular orientational structure, providing a flexible platform for the modification of surface properties with this exciting new class of nanodiamond materials.

  17. An instrument for the investigation of actinides with spin resolved photoelectron spectroscopy and bremsstrahlung isochromat spectroscopy

    SciTech Connect (OSTI)

    Yu, S.-W.; Tobin, J. G.; Chung, B. W.

    2011-01-01

    A new system for spin resolved photoelectron spectroscopy and bremsstrahlung isochromat spectroscopy has been built and commissioned at Lawrence Livermore National Laboratory for the investigation of the electronic structure of the actinides.Actinide materials are very toxic and radioactive and therefore cannot be brought to most general user facilities for spectroscopic studies. The technical details of the new system and preliminary data obtained therein will be presented and discussed.

  18. SMB, X-ray Fluorescence Imaging

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

    Beam line 14-3b is a bending magnet side station dedicated to X-ray imaging and micro X-ray absorption spectroscopy of biological, biomedical, materials, and geological samples. ...

  19. Spatially resolved high-resolution x-ray spectroscopy of high-current plasma-focus discharges

    SciTech Connect (OSTI)

    ZajaPc, S.; Rzadkiewicz, J.; Scholz, M.; Paduch, M.; Zielinska, E.; Rosmej, O.; Yongtao, Zhao; Gojska, A.

    2010-10-15

    Soft x-ray emission from a Mather-type plasma-focus device (PF-1000) operated at {approx}400 kJ was measured. The high density and temperature plasma were generated by the discharge in the deuterium-argon gas mixture in the modified (high-current) plasma-focus configuration. A spherically bent mica crystal spectrograph viewing the axial output of the pinch region was used to measure the x-ray spectra. Spatially resolved spectra including the characteristic x-ray lines of highly ionized Ar and continua were recorded by means of an x-ray film. The x-ray emission of PF-1000 device was studied at different areas of the pinch.

  20. Simulating Valence-to-Core X-ray Emission Spectroscopy of Transition Metal Complexes with Time-Dependent Density Functional Theory

    SciTech Connect (OSTI)

    Zhang, Yu; Mukamel, Shaul; Khalil, Munira; Govind, Niranjan

    2015-11-09

    Valence-to-core (VtC) X-ray emission spectroscopy (XES) has emerged as a power- ful technique for the structural characterization of complex organometallic compounds in realistic environments. Since the spectrum represents electronic transitions from the ligand molecular orbitals to the core holes of the metal centers, the approach is more chemically sensitive to the metal-ligand bonding character compared with con- ventional X-ray absorption techniques. In this paper we study how linear-response time-dependent density functional theory (LR-TDDFT) can be harnessed to simulate K-edge VtC X-ray emission spectra reliably. LR-TDDFT allows one to go beyond the single-particle picture that has been extensively used to simulate VtC-XES. We con- sider seven low- and high-spin model complexes involving chromium, manganese and iron transition metal centers. Our results are in good agreement with experiment.

  1. X-ray absorption spectroscopy of LiBF 4 in propylene carbonate. A model lithium ion battery electrolyte

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

    Smith, Jacob W.; Lam, Royce K.; Sheardy, Alex T.; Shih, Orion; Rizzuto, Anthony M.; Borodin, Oleg; Harris, Stephen J.; Prendergast, David; Saykally, Richard J.

    2014-08-20

    Since their introduction into the commercial marketplace in 1991, lithium ion batteries have become increasingly ubiquitous in portable technology. Nevertheless, improvements to existing battery technology are necessary to expand their utility for larger-scale applications, such as electric vehicles. Advances may be realized from improvements to the liquid electrolyte; however, current understanding of the liquid structure and properties remains incomplete. X-ray absorption spectroscopy of solutions of LiBF4 in propylene carbonate (PC), interpreted using first-principles electronic structure calculations within the eXcited electron and Core Hole (XCH) approximation, yields new insight into the solvation structure of the Li+ ion in this model electrolyte.more » By generating linear combinations of the computed spectra of Li+-associating and free PC molecules and comparing to the experimental spectrum, we find a Li+–solvent interaction number of 4.5. This result suggests that computational models of lithium ion battery electrolytes should move beyond tetrahedral coordination structures.« less

  2. Some new schemes for producing high-accuracy elliptical X-ray mirrors by elastic bending

    SciTech Connect (OSTI)

    Padmore, H.A.; Howells, M.R.; Irick, S.; Renner, T.; Sandler, R.; Koo, Y.-M.

    1996-08-01

    Although x-ray micro-foci can be produced by a variety of diffractive methods, grazing incidence mirrors are the only route to an achromatic focus. In this paper we describe our efforts to produce elliptically shaped mirrors with the very high figure accuracy necessary for producing a micro-focus. The motivation for this work is provided by the need to produce achromatic foci for a range of applications ranging from tunable micro-focus x-ray photoelectron spectroscopy ({mu}-XPS) at soft x-ray energies to micro-focus white beam x-ray diffraction ({mu}-XRD) at hard x-ray energies. We describe the methodology of beam bending, a practical example of a system we have produced for {mu}-XRD, and results demonstrating the production of a surface with micro-radian figure accuracy.

  3. High energy resolution five-crystal spectrometer for high quality fluorescence and absorption measurements on an x-ray absorption spectroscopy beamline

    SciTech Connect (OSTI)

    Llorens, Isabelle; Lahera, Eric; Delnet, William; Proux, Olivier; Dermigny, Quentin; Gelebart, Frederic; Morand, Marc; Shukla, Abhay; Bardou, Nathalie; Ulrich, Olivier; and others

    2012-06-15

    Fluorescence detection is classically achieved with a solid state detector (SSD) on x-ray absorption spectroscopy (XAS) beamlines. This kind of detection however presents some limitations related to the limited energy resolution and saturation. Crystal analyzer spectrometers (CAS) based on a Johann-type geometry have been developed to overcome these limitations. We have tested and installed such a system on the BM30B/CRG-FAME XAS beamline at the ESRF dedicated to the structural investigation of very dilute systems in environmental, material and biological sciences. The spectrometer has been designed to be a mobile device for easy integration in multi-purpose hard x-ray synchrotron beamlines or even with a laboratory x-ray source. The CAS allows to collect x-ray photons from a large solid angle with five spherically bent crystals. It will cover a large energy range allowing to probe fluorescence lines characteristic of all the elements from Ca (Z = 20) to U (Z = 92). It provides an energy resolution of 1-2 eV. XAS spectroscopy is the main application of this device even if other spectroscopic techniques (RIXS, XES, XRS, etc.) can be also achieved with it. The performances of the CAS are illustrated by two experiments that are difficult or impossible to perform with SSD and the complementarity of the CAS vs SSD detectors is discussed.

  4. X-ray polarization spectroscopy to study anisotropic velocity distribution of hot electrons produced by an ultra-high-intensity laser

    SciTech Connect (OSTI)

    Inubushi, Y.; Okano, Y.; Nishimura, H.; Cai, H.; Nagatomo, H.; Kai, T.; Fujioka, S.; Nakamura, T.; Johzaki, T.; Mima, K.; Kawamura, T.; Batani, D.; Morace, A.; Redaelli, R.; Fourment, C.; Santos, J. J.; Malka, G.

    2010-03-15

    The anisotropy of the hot-electron velocity distribution in ultra-high-intensity laser produced plasma was studied with x-ray polarization spectroscopy using multilayer planar targets including x-ray emission tracer in the middle layer. This measurement serves as a diagnostic for hot-electron transport from the laser-plasma interaction region to the overdense region where drastic changes in the isotropy of the electron velocity distribution are observed. These polarization degrees are consistent with analysis of a three-dimensional polarization spectroscopy model coupled with particle-in-cell simulations. Electron velocity distribution in the underdense region is affected by the electric field of the laser and that in the overdense region becomes wider with increase in the tracer depth. A full-angular spread in the overdense region of 22.4 deg.{sub -2.4}{sup +5.4} was obtained from the measured polarization degree.

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

    SciTech Connect (OSTI)

    D.W. Lynch

    2004-09-30

    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.

  6. An analytic model for the response of a CZT detector in diagnostic energy dispersive x-ray spectroscopy

    SciTech Connect (OSTI)

    LeClair, Robert J.; Wang Yinkun; Zhao Peiying; Boileau, Michel; Wang, Lilie; Fleurot, Fabrice [Department of Physics and Astronomy, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario P3E 2C6 (Canada) and Biomolecular Sciences Program, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario P3E 2C6 (Canada); Department of Physics and Astronomy, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario P3E 2C6 (Canada)

    2006-05-15

    A CdZnTe detector (CZTD) can be very useful for measuring diagnostic x-ray spectra. The semiconductor detector does, however, exhibit poor hole transport properties and fluorescence generation upon atomic de-excitations. This article describes an analytic model to characterize these two phenomena that occur when a CZTD is exposed to diagnostic x rays. The analytical detector response functions compare well with those obtained via Monte Carlo calculations. The response functions were applied to 50, 80, and 110 kV x-ray spectra. Two 50 kV spectra were measured; one with no filtration and the other with 1.35 mm Al filtration. The unfiltered spectrum was numerically filtered with 1.35 mm of Al in order to see whether the recovered spectrum resembled the filtered spectrum actually measured. A deviation curve was obtained by subtracting one curve from the other on an energy bin by bin basis. The deviation pattern fluctuated around the zero line when corrections were applied to both spectra. Significant deviations from zero towards the lower energies were observed when the uncorrected spectra were used. Beside visual observations, the exposure obtained using the numerically attenuated unfiltered beam was compared to the exposure calculated with the actual filtered beam. The percent differences were 0.8% when corrections were applied and 25% for no corrections. The model can be used to correct diagnostic x-ray spectra measured with a CdZnTe detector.

  7. NuSTAR study of hard X-ray morphology and spectroscopy of PWN G21.50.9

    SciTech Connect (OSTI)

    Nynka, Melania; Hailey, Charles J.; Gotthelf, Eric V.; Mori, Kaya; Perez, Kerstin [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Reynolds, Stephen P. [Physics Department, NC State University, Raleigh, NC 27695 (United States); An, Hongjun [Department of Physics, McGill University, Rutherford Physics Building, 3600 University Street, Montreal, Quebec H3A 2T8 (Canada); Baganoff, Frederick K. [Center for Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139-4307 (United States); Boggs, Steven E.; Krivonos, Roman; Zoglauer, Andreas [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Christensen, Finn E. [DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Craig, William W. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Grefenstette, Brian W.; Harrison, Fiona A.; Madsen, Kristin K. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Wik, Daniel R.; Zhang, William W. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2014-07-01

    We present NuSTAR high-energy X-ray observations of the pulsar wind nebula (PWN)/supernova remnant G21.50.9. We detect integrated emission from the nebula up to ?40 keV, and resolve individual spatial features over a broad X-ray band for the first time. The morphology seen by NuSTAR agrees well with that seen by XMM-Newton and Chandra below 10 keV. At high energies, NuSTAR clearly detects non-thermal emission up to ?20 keV that extends along the eastern and northern rim of the supernova shell. The broadband images clearly demonstrate that X-ray emission from the North Spur and Eastern Limb results predominantly from non-thermal processes. We detect a break in the spatially integrated X-ray spectrum at ?9 keV that cannot be reproduced by current spectral energy distribution models, implying either a more complex electron injection spectrum or an additional process such as diffusion compared to what has been considered in previous work. We use spatially resolved maps to derive an energy-dependent cooling length scale, L(E)?E{sup m} with m = 0.21 0.01. We find this to be inconsistent with the model for the morphological evolution with energy described by Kennel and Coroniti. This value, along with the observed steepening in power-law index between radio and X-ray, can be quantitatively explained as an energy-loss spectral break in the simple scaling model of Reynolds, assuming particle advection dominates over diffusion. This interpretation requires a substantial departure from spherical magnetohydrodynamic, magnetic-flux-conserving outflow, most plausibly in the form of turbulent magnetic-field amplification.

  8. Room temperature reaction of oxygen with gold: an in situ ambient-pressure X-ray photoelectron spectroscopy investigation

    SciTech Connect (OSTI)

    Jiang, Peng; Porsgaard, Soeren; Borondics, Ferenc; Kober, Mariana; Caballero, Alfonso; Bluhm, Hendrik; Besenbacher, Flemming; Salmeron, Miquel

    2010-02-01

    Gold is commonly regarded as the most inert element.1 However, the discovery of the exceptional catalytic properties of gold nanoparticles (NPs) for low temperature CO oxidation2 initiated great interest due to its promising applications and spawned a large number of studies devoted to the understanding of the reaction mechanism.3-6 Nevertheless, no consistent and conclusive picture has arisen.7-13

  9. Microgap x-ray detector

    DOE Patents [OSTI]

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

    1994-05-03

    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.

  10. Microgap x-ray detector

    DOE Patents [OSTI]

    Wuest, Craig R.; Bionta, Richard M.; Ables, Elden

    1994-01-01

    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.

  11. An ultra-high vacuum electrochemical flow cell for in situ/operando soft X-ray spectroscopy study

    SciTech Connect (OSTI)

    Bora, Debajeet K. E-mail: jguo@lbl.gov; Glans, Per-Anders; Pepper, John; Liu, Yi-Sheng; Guo, J.-H. E-mail: jguo@lbl.gov; Du, Chun; Wang, Dunwei

    2014-04-15

    An in situ flow electrochemical cell has been designed and fabricated to allow better seal under UHV chamber thus to achieve a good signal to noise ratio in fluorescence yield detection of X-ray absorption spectra for spectroelectrochemical study. The cell also stabilizes the thin silicon nitride membrane window in an effective manner so that the liquid cell remains intact during X-ray absorption experiments. With the improved design of the liquid cell, electrochemical experiments such as cyclic voltammetry have been performed for 10 cycles with a good stability of sample window. Also an operando electrochemical experiment during photoelectrochemistry has been performed on n-type hematite electrode deposited on silicon nitride window. The experiment allows us to observe the formation of two extra electronic transitions before pre edge of O K-edge spectra.

  12. Magnetic properties of GdT2Zn20 (T = Fe, Co) investigated by x-ray diffraction and spectroscopy

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

    J. R. L. Mardegan; Fabbris, G.; Francoual, S.; Veiga, L. S. I.; Strempfer, J.; Haskel, D.; Ribeiro, R. A.; Avila, M. A.; Giles, C.

    2016-01-26

    In this study, we investigate the magnetic and electronic properties of the GdT2Zn20 (T=Fe and Co) compounds using x-ray resonant magnetic scattering (XRMS), x-ray absorption near-edge structure (XANES), and x-ray magnetic circular dichroism (XMCD). The XRMS measurements reveal that GdCo2Zn20 has a commensurate antiferromagnetic spin structure with a magnetic propagation vector →/τ = (12,12,12) below the Néel temperature (TN ~ 5.7 K). Only the Gd ions carry a magnetic moment forming an antiferromagnetic structure with magnetic representation Γ6. For the ferromagnetic GdFe2Zn20 compound, an extensive investigation was performed at low temperature and under magnetic field using XANES and XMCD. Amore » strong XMCD signal of about 12.5% and 9.7% is observed below the Curie temperature (TC ~ 85K) at the Gd L2 and L3 edges, respectively. In addition, a small magnetic signal of about 0.06% of the jump is recorded at the Zn K edge, suggesting that the Zn 4p states are spin polarized by the Gd 5d extended orbitals.« less

  13. High resolution absorption spectroscopy of exploding wire plasmas using an x-pinch x-ray source and spherically bent crystal

    SciTech Connect (OSTI)

    Knapp, P. F.; Pikuz, S. A.; Shelkovenko, T. A.; Hammer, D. A.; Hansen, S. B.

    2011-06-15

    We present here the use of absorption spectroscopy of the continuum radiation from x-pinch-produced point x-ray sources as a diagnostic to investigate the properties of aluminum plasmas created by pulsed power machines. This technique is being developed to determine the charge state, temperature, and density as a function of time and space under conditions that are inaccessible to x-ray emission spectroscopic diagnostics. The apparatus and its characterization are described, and the spectrometer dispersion, magnification, and resolution are calculated and compared with experimental results. Spectral resolution of about 5000 and spatial resolution of about 20 {mu}m are demonstrated. This spectral resolution is the highest available to date in an absorption experiment. The beneficial properties of the x-pinch x-ray source as the backlighter for this diagnostic are the small source size (<5 {mu}m), smooth continuum radiation, and short pulse duration (<0.1 ns). Results from a closely spaced (1 mm) exploding wire pair are shown and the general features are discussed.

  14. High-Pressure Raman Spectroscopy and X-ray Diffraction Studies of a Terpolymer of Tetrafluoroethylene-Hexafluoropropylene-Vinylidene Fluoride: THV 500

    SciTech Connect (OSTI)

    Emmons, E.D.; Velisavljevic, N.; Schoonover, J.R.; Dattelbaum, D.M.

    2008-04-02

    High-pressure Raman spectroscopy and X-ray diffraction of THV 500, a terpolymer of tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride, were performed using diamond anvil cells (DAC). Changes in the interatomic spacing as well as shifts of several of the vibrational bands as a function of pressure were measured up to {approx}10 GPa. The changes in interatomic spacing and shifts of the vibrational bands are compared to those of polytetrafluoroethylene, showing the effects of copolymerization and reduced crystallinity. The high-pressure behavior of polymers is a relatively unexplored field but is becoming increasingly important due to applications where polymers experience extreme conditions.

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

    DOE Patents [OSTI]

    Wang, C.L.

    1982-09-27

    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.

  16. Quantitative Phase Composition of TiO2-Coated Nanoporous-Au Monoliths by X-ray Absorption Spectroscopy and Correlations to Catalytic

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

    Bagge-Hansen, Michael; Wichmann, Andre; Wittstock, Arne; Lee, Jonathan R. I.; Ye, Jianchao; Willey, Trevor M.; Kuntz, Joshua D.; van Buuren, Tony; Biener, Juergen; Baumer, Marcus; et al

    2014-02-03

    Porous titania/metal composite materials have many potential applications in the fields of green catalysis, energy harvesting, and storage in which both the overall morphology of the nanoporous host material and the crystallographic phase of the titania (TiO 2) guest determine the material’s performance. New insights into the structure–function relationships of these materials were obtained by near-edge X-ray absorption fine structure (NEXAFS) spectroscopy that, for example, provides quantitative crystallographic phase composition from ultrathin, nanostructured titania films, including sensitivity to amorphous components. We demonstrate that crystallographic phase, morphology, and catalytic activity of TiO 2-functionalized nanoporous gold (np-Au) can be controlled by amore » simple annealing procedure (T < 1300 K). The material was prepared by atomic layer deposition of ~2 nm thick TiO2 on millimeter-sized samples of np-Au (40–50 nm mean ligament size) and catalytically investigated with respect to aerobic CO oxidation. Moreover, the annealing-induced changes in catalytic activity are correlated with concurrent morphology and phase changes as provided by cross-sectional scanning electron microscopy, transmission electron microscopy, and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy.« less

  17. X-Ray Diagnostics

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

    including film developing and scanning, and image plate scanning. Related images X-ray framing camera being loaded into the TIM in the Trident North Target Area. X-ray framing...

  18. Soft X-ray techniques to study mesoscale magnetism

    SciTech Connect (OSTI)

    Kortright, Jeffrey B.

    2003-06-26

    Heterogeneity in magnetization (M) is ubiquitous in modern systems. Even in nominally homogeneous materials, domains or pinning centers typically mediate magnetization reversal. Fundamental lengths determining M structure include the domain wall width and the exchange stiffness length, typically in the 4-400 nm range. Chemical heterogeneity (phase separation, polycrystalline microstructure, lithographic or other patterning, etc.) with length scales from nanometers to microns is often introduced to influence magnetic properties. With 1-2 nm wavelengths {lambda}, soft x-rays in principle can resolve structure down to {lambda}/2, and are well suited to study these mesoscopic length scales [1, 2]. This article highlights recent advances in resonant soft x-ray methods to resolve lateral magnetic structure [3], and discusses some of their relative merits and limitations. Only techniques detecting x-ray photons (rather than photo-electrons) are considered [4], since they are compatible with strong applied fields to probe relatively deeply into samples. The magneto-optical (MO) effects discovered by Faraday and Kerr were observed in the x-ray range over a century later, first at ''hard'' wavelengths in diffraction experiments probing interatomic magnetic structure [5]. In the soft x-ray range, magnetic linear [6] and circular [7] dichroism spectroscopies first developed that average over lateral magnetic structure. These large resonant MO effects enable different approaches to study magnetic structure or heterogeneity that can be categorized as microscopy or scattering [1]. Direct images of magnetic structure result from photo-emission electron microscopes [4, 8] and zone-plate microscopes [9, 10]. Scattering techniques extended into the soft x-ray include familiar specular reflection that laterally averages over structure but can provide depth-resolved information, and diffuse scattering and diffraction that provide direct information about lateral magnetic structure. Scattering techniques are further classified as partially for fully coherent according to the extent of transverse coherence of the incident beam.

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

    SciTech Connect (OSTI)

    Jin, W.; Chen, Z. Y. 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.; Lee, S. G.; Shi, Y. J.

    2014-02-15

    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.

  20. Direct speciation analysis of arsenic in sub-cellular compartments using micro-X-ray absorption spectroscopy

    SciTech Connect (OSTI)

    Bacquart, Thomas; Deves, Guillaume; Ortega, Richard

    2010-07-15

    Identification of arsenic chemical species at a sub-cellular level is a key to understanding the mechanisms involved in arsenic toxicology and antitumor pharmacology. When performed with a microbeam, X-ray absorption near-edge structure ({mu}-XANES) enables the direct speciation analysis of arsenic in sub-cellular compartments avoiding cell fractionation and other preparation steps that might modify the chemical species. This methodology couples tracking of cellular organelles in a single cell by confocal or epifluorescence microscopy with local analysis of chemical species by {mu}-XANES. Here we report the results obtained with a {mu}-XANES experimental setup based on Kirkpatrick-Baez X-ray focusing optics that maintains high flux of incoming radiation (>10{sup 11} ph/s) at micrometric spatial resolution (1.5x4.0 {mu}m{sup 2}). This original experimental setup enabled the direct speciation analysis of arsenic in sub-cellular organelles with a 10{sup -15} g detection limit. {mu}-XANES shows that inorganic arsenite, As(OH){sub 3}, is the main form of arsenic in the cytosol, nucleus, and mitochondrial network of cultured cancer cells exposed to As{sub 2}O{sub 3}. On the other hand, a predominance of As(III) species is observed in HepG2 cells exposed to As(OH){sub 3} with, in some cases, oxidation to a pentavalent form in nuclear structures of HepG2 cells. The observation of intra-nuclear mixed redox states suggests an inter-individual variability in a cell population that can only be evidenced with direct sub-cellular speciation analysis.

  1. X-Ray Diagnostics

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

    X-Ray Diagnostics X-Ray Diagnostics Maintenance of existing devices and development of advanced concepts Contact John Oertel (505) 665-3246 Email Hot, dense matter produced by intense laser interaction with a solid target often produces x-rays with energies from 100 eV to those exceeding 100 keV. A suite of diagnostics and methods have been deployed at Trident to diagnose the x-ray emission from laser-matter interaction experiments, or to use the x-rays as a probe of dense matter. These

  2. A high resolution and large solid angle x-ray Raman spectroscopy end-station at the Stanford Synchrotron Radiation Lightsource

    SciTech Connect (OSTI)

    Sokaras, D.; Nordlund, D.; Weng, T.-C.; Velikov, P.; Wenger, D.; Garachtchenko, A.; George, M.; Borzenets, V.; Johnson, B.; Rabedeau, T.; Mori, R. Alonso; Bergmann, U.; Qian, Q.

    2012-04-15

    We present a new x-ray Raman spectroscopy end-station recently developed, installed, and operated at the Stanford Synchrotron Radiation Lightsource. The end-station is located at wiggler beamline 6-2 equipped with two monochromators-Si(111) and Si(311) as well as collimating and focusing optics. It consists of two multi-crystal Johann type spectrometers arranged on intersecting Rowland circles of 1 m diameter. The first one, positioned at the forward scattering angles (low-q), consists of 40 spherically bent and diced Si(110) crystals with 100 mm diameters providing about 1.9% of 4{pi} sr solid angle of detection. When operated in the (440) order in combination with the Si (311) monochromator, an overall energy resolution of 270 meV is obtained at 6462.20 eV. The second spectrometer, consisting of 14 spherically bent Si(110) crystal analyzers (not diced), is positioned at the backward scattering angles (high-q) enabling the study of non-dipole transitions. The solid angle of this spectrometer is about 0.9% of 4{pi} sr, with a combined energy resolution of 600 meV using the Si (311) monochromator. These features exceed the specifications of currently existing relevant instrumentation, opening new opportunities for the routine application of this photon-in/photon-out hard x-ray technique to emerging research in multidisciplinary scientific fields, such as energy-related sciences, material sciences, physical chemistry, etc.

  3. High-resolution Elemental Mapping of Human Placental Chorionic Villi Using Synchrotron X-ray Fluorescence Spectroscopy

    SciTech Connect (OSTI)

    Punshon, Tracy; Chen, Si; Finney, Lydia; Howard, Louisa; Jackson, Brian P.; Karagas, Margaret R.; Ornvold, Kim

    2015-09-01

    The placenta is the organ that mediates transport of nutrients and waste materials between mother and fetus. Synchrotron X-ray fluorescence (SXRF) microanalysis is a tool for imaging the distribution and quantity of elements in biological tissue, which can be used to study metal transport across biological membranes. Our aims were to pilot placental biopsy specimen preparation techniques that could be integrated into an ongoing epidemiology birth cohort study without harming rates of sample acquisition. We studied the effects of fixative (formalin or glutaraldehyde) and storage duration (30 days or immediate processing) on metal distribution and abundance and investigated a thaw-fixation protocol for archived specimens stored at -80 A degrees C. We measured fixative elemental composition with and without a placental biopsy via inductively coupled plasma mass spectrometry (ICP-MS) to quantify fixative-induced elemental changes. Formalin-fixed specimens showed hemolysis of erythrocytes. The glutaraldehyde-paraformaldehyde solution in HEPES buffer (GTA-HEPES) had superior anatomical preservation, avoided hemolysis, and minimized elemental loss, although some cross-linking of exogenous Zn was evident. Elemental loss from tissue stored in fixative for 1 month showed variable losses (a parts per thousand 40 % with GTA-HEPES), suggesting storage duration be controlled for. Thawing of tissue held at -80 A degrees C in a GTA-HEPES solution provided high-quality visual images and elemental images

  4. Influence of structural disorder on soft x-ray optical behavior of NbC thin films

    SciTech Connect (OSTI)

    Singh, Amol E-mail: rrcat.amol@gmail.com; Modi, Mohammed H.; Sinha, A. K.; Lodha, G. S.; Rajput, Parasmani

    2015-05-07

    Structural and chemical properties of compound materials are modified, when thin films are formed from bulk materials. To understand these changes, a study was pursued on niobium carbide (NbC) thin films of different thicknesses deposited on Si (100) substrate using ion beam sputtering technique. Optical response of the film was measured in 436?nm wavelength region using Indus-1 reflectivity beamline. A discrepancy in soft x-ray performance of NbC film was observed which could not be explained with Henke's tabulated data (see http://henke.lbl.gov/optical{sub c}onstants/ ). In order to understand this, detailed structural and chemical investigations were carried out using x-ray reflectivity, grazing incidence x-ray diffraction, x-ray absorption near edge structure, extended x-ray absorption fine structure, and x-ray photoelectron spectroscopy techniques. It was found that the presence of unreacted carbon and Nb deficiency due to reduced Nb-Nb coordination are responsible for lower soft x-ray reflectivity performance. NbC is an important material for soft x-ray optical devices, hence the structural disorder need to be controlled to achieve the best performances.

  5. Phase transitions in heated Sr{sub 2}MgTeO{sub 6} double perovskite oxide probed by X-ray diffraction and Raman spectroscopy

    SciTech Connect (OSTI)

    Manoun, Bouchaib Tamraoui, Y.; Lazor, P.; Yang, Wenge

    2013-12-23

    Double-perovskite oxide Sr{sub 2}MgTeO{sub 6} has been synthetized, and its crystal structure was probed by the technique of X-ray diffraction at room temperature. The structure is monoclinic, space group I2/m. Temperature-induced phase transitions in this compound were investigated by Raman spectroscopy up to 550?C. Two low-wavenumber modes corresponding to external lattice vibrations merge at temperature of around 100?C, indicating a phase transition from the monoclinic (I2/m) to the tetragonal (I4/m) structure. At 300?C, changes in the slopes of temperature dependencies of external and OTeO bending modes are detected and interpreted as a second phase transition from the tetragonal (I4/m) to the cubic (Fm-3m) structure.

  6. The apparent absence of chemical sensitivity in the 4d and 5d X-ray absorption spectroscopy of uranium compounds

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

    Tobin, J. G.

    2013-05-03

    X-ray absorption spectroscopy (XAS) and related derivative measurements have been used to demonstrate that the Pu 5f states are strongly relativistic and have a 5f occupation number near 5. Owing to the success in this regime, it has been argued that the XAS measurements should be a powerful tool to probe 5f occupation variation, both as a function of elemental nature (actinide atomic number) and as a function of physical and chemical perturbation, e.g., oxidation state. We show that XAS and its related measurements fail in this latter aspect for a wide variety of uranium compounds and materials. Possible causesmore » will be discussed.« less

  7. Particle size effect of hydride formation and surface hydrogen absorption of nanosized palladium catalysts : L{sub 3} edge vs K edge x-ray absorption spectroscopy.

    SciTech Connect (OSTI)

    Tew, M. W.; Miller, J. T.; van Bokhoven, J. A.

    2009-08-01

    The particle size effect on the formation of palladium hydride and on surface hydrogen adsorption was studied at room temperature using in situ X-ray absorption spectroscopy at the Pd K and L{sub 3} edges. Hydride formation was indirectly observed by lattice expansion in Pd K edge XANES spectra and by EXAFS analysis. Hydride formation was directly detected in the L{sub 3} edge spectra. A characteristic spectral feature caused by the formation of a Pd-H antibonding state showed strong particle size dependence. The L{sub 3} edge spectra were reproduced using full multiple scattering analysis and density of state calculations, and the contributions of bulk absorbed and surface hydrogen to the XANES spectra could be distinguished. The ratio of hydrogen on the surface versus that in the bulk increased with decreasing particle size, and smaller particles dissolved less hydrogen.

  8. The ALS X-Ray Streak Camera: Bringing the Ultrafast and Ultrasmall...

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

    been combined with high spatial resolution in a streak camera. In an x-ray streak camera system, the photocathode converts the x-ray signal into a photoelectron analog signal. The...

  9. 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.

  10. X-ray beamsplitter

    DOE Patents [OSTI]

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

    1987-08-07

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

  11. X-ray beamsplitter

    DOE Patents [OSTI]

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

    1989-01-01

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

  12. X-ray generator

    DOE Patents [OSTI]

    Dawson, John M.

    1976-01-01

    Apparatus and method for producing coherent secondary x-rays that are controlled as to direction by illuminating a mixture of high z and low z gases with an intense burst of primary x-rays. The primary x-rays are produced with a laser activated plasma, and these x-rays strip off the electrons of the high z atoms in the lasing medium, while the low z atoms retain their electrons. The neutral atoms transfer electrons to highly excited states of the highly striped high z ions giving an inverted population which produces the desired coherent x-rays. In one embodiment, a laser, light beam provides a laser spark that produces the intense burst of coherent x-rays that illuminates the mixture of high z and low z gases, whereby the high z atoms are stripped while the low z ones are not, giving the desired mixture of highly ionized and neutral atoms. To this end, the laser spark is produced by injecting a laser light beam, or a plurality of beams, into a first gas in a cylindrical container having an adjacent second gas layer co-axial therewith, the laser producing a plasma and the intense primary x-rays in the first gas, and the second gas containing the high and low atomic number elements for receiving the primary x-rays, whereupon the secondary x-rays are produced therein by stripping desired ions in a neutral gas and transfer of electrons to highly excited states of the stripped ions from the unionized atoms. Means for magnetically confining and stabilizing the plasma are disclosed for controlling the direction of the x-rays.

  13. X-ray laser

    DOE Patents [OSTI]

    Nilsen, Joseph

    1991-01-01

    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.

  14. 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

    2008-05-21

    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.

  15. Simulating Ru L3-Edge X-ray Absorption Spectroscopy with Time-Dependent Density Functional Theory: Model Complexes and Electron Localization in Mixed-Valence Metal Dimers

    SciTech Connect (OSTI)

    Kuiken, Benjamin E. Van; Valiev, Marat; Daifuku, Stephanie L.; Bannan, Caitlin; Strader, Matthew L.; Cho, Hana; Huse, Nils; Schoenlein, Robert W.; Govind, Niranjan; Khalil, Munira

    2013-04-26

    Ruthenium L3-edge X-ray absorption (XA) spectroscopy probes unoccupied 4d orbitals of the metal atom and is increasingly being used to investigate the local electronic structure in ground and excited electronic states of Ru complexes. The simultaneous development of computational tools for simulating Ru L3-edge spectra is crucial for interpreting the spectral features at a molecular level. This study demonstrates that time-dependent density functional theory (TDDFT) is a viable and predictive tool for simulating ruthenium L3-edge XA spectroscopy. We systematically investigate the effects of exchange correlation functional and implicit and explicit solvent interactions on a series of RuII and RuIII complexes in their ground and electronic excited states. The TDDFT simulations reproduce all of the experimentally observed features in Ru L3-edge XA spectra within the experimental resolution (0.4 eV). Our simulations identify ligand-specific charge transfer features in complicated Ru L3-edge spectra of [Ru(CN)6]4- and RuII polypyridyl complexes illustrating the advantage of using TDDFT in complex systems. We conclude that the B3LYP functional most accurately predicts the transition energies of charge transfer features in these systems. We use our TDDFT approach to simulate experimental Ru L3-edge XA spectra of transition metal mixed-valence dimers of the form [(NC)5MII-CN-RuIII(NH3)5] (where M = Fe or Ru) dissolved in water. Our study determines the spectral signatures of electron delocalization in Ru L3-edge XA spectra. We find that the inclusion of explicit solvent molecules is necessary for reproducing the spectral features and the experimentally determined valencies in these mixed-valence complexes. This study validates the use of TDDFT for simulating Ru 2p excitations using popular quantum chemistry codes and providing a powerful interpretive tool for equilibrium and ultrafast Ru L3-edge XA spectroscopy.

  16. X-Ray Detection

    Office of Scientific and Technical Information (OSTI)

    ratio, I I on I off , recorded with plus (+, blue) and minus (-, red) x-ray helicities. This measurement was taken at -5 mA, which corresponds to a current...

  17. ALS X-Rays Shine a New Light on Catalysis

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

    were able to directly observe redox processes in thin-film iron and cobalt perovskite oxide electrocatalysts using surface-sensitive, x-ray absorption spectroscopy while...

  18. X-Ray Fluorescence (XRF) | Open Energy Information

    Open Energy Info (EERE)

    Dispersive Spectroscopy (WDS) typically performed using a SEM or EPMA, and X-Ray Diffraction (XRD) analyses. Rock Lab Analysis Core Analysis Cuttings Analysis Isotopic...

  19. Dissolution of thin iron oxide films used as models for iron passive films studied by in situ X-ray absorption near-edge spectroscopy

    SciTech Connect (OSTI)

    Virtanen, S; Schmuki, P.; Davenport, A.J.; Vitus, C.M.

    1997-01-01

    This paper reports results from X-ray absorption near-edge spectroscopy (XANES) studies during polarization of thin sputter-deposited iron oxide films in acidic solutions. The dissolution rate of iron oxides in acidic solutions was found to be strongly increased by the presence of Fe{sup 2+} in the oxide. During anodic polarization in acidic solutions, it is found that dissolution is accelerated by chloride anions in comparison with sulfates. In HCl solutions of increasing concentration, not only does the pH decrease, but also the increasing chloride concentration accelerates dissolution. On the other hand, the dissolution rate in sulfuric acid does not depend on the sulfate (bisulfate) concentration. During anodic polarization, the dissolution rate is fairly independent of the potential, except at very high anodic potentials, and the XANES spectra reveal no changes in the average oxide valence during anodic polarization. Thus the dissolution that takes place is mostly chemical rather than electrochemical. During cathodic polarization, the dissolution rate is independent of the anion in the electrolyte. The findings are interpreted in terms of the negative surface charge of n-type oxides at potentials lower than the flatband potential, retarding anion adsorption on the surface. Hence it is suggested that the detrimental role of chloride anions on the stability of iron oxide films is due to a surface complexation effect. The findings and their relevance to the stability of natural passive films on iron surfaces are discussed.

  20. X-ray absorption spectroscopy of LiBF 4 in propylene carbonate. A model lithium ion battery electrolyte

    SciTech Connect (OSTI)

    Smith, Jacob W.; Lam, Royce K.; Sheardy, Alex T.; Shih, Orion; Rizzuto, Anthony M.; Borodin, Oleg; Harris, Stephen J.; Prendergast, David; Saykally, Richard J.

    2014-08-20

    Since their introduction into the commercial marketplace in 1991, lithium ion batteries have become increasingly ubiquitous in portable technology. Nevertheless, improvements to existing battery technology are necessary to expand their utility for larger-scale applications, such as electric vehicles. Advances may be realized from improvements to the liquid electrolyte; however, current understanding of the liquid structure and properties remains incomplete. X-ray absorption spectroscopy of solutions of LiBF4 in propylene carbonate (PC), interpreted using first-principles electronic structure calculations within the eXcited electron and Core Hole (XCH) approximation, yields new insight into the solvation structure of the Li+ ion in this model electrolyte. By generating linear combinations of the computed spectra of Li+-associating and free PC molecules and comparing to the experimental spectrum, we find a Li+–solvent interaction number of 4.5. This result suggests that computational models of lithium ion battery electrolytes should move beyond tetrahedral coordination structures.

  1. Probing the f-state configuration of URu2Si2 with U LIII-edge resonant x-ray absorption spectroscopy

    SciTech Connect (OSTI)

    Medling, S. A.; Booth, C. H.; Tobin, J. G.; Baumbach, R. E.; Bauer, E. D.; Sokaras, D.; Nordlund, D.; Weng, T. C.

    2015-09-05

    It has often been said that the most interesting ph- syics occurs when competing interactions are of nearly the same magnitude. Such a situation is surely oc- curing at URu2Si2’s so-called “hidden-order transition”, which garners its name from the missing entropy at a 17.5 K phase transition relative to that expected for a conventional antiferromagnetic phase transition, de- spite the presence of only a very small ordered mag- netic moment.? Despite this discrepancy being identi- fied in 1985, the identification of the order parameter remains elusive, although progress toward understand- ing this transition has been steady since that time, and URu2Si2 remains an important research subject today.? The work described below provides measures of the 5f orbital occupancy and itinerancy using resonant x-ray emission spectroscopy (RXES) at the U LIII absorption edge and measuring U L 1 emission that potentially acts as a dividing line between different classes of “hidden- order” theories.

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

    SciTech Connect (OSTI)

    Goldmann, Maximilian; Miguel-Sánchez, Javier; West, Adam H. C.; Yoder, Bruce L.; Signorell, Ruth

    2015-06-14

    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. First, aerosol photoemission studies can be performed for many different materials, including liquids. Second, 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.

  3. X-ray fluorescence mapping

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

    X-Ray Microscopy and Imaging: X-ray Fluorescence Mapping Of increasing scientific interest is the detection, quantification and mapping of elemental content of samples, often down...

  4. X-ray microtomography

    SciTech Connect (OSTI)

    Landis, Eric N.; Keane, Denis T.

    2010-12-15

    In this tutorial, we describe X-ray microtomography as a technique to nondestructively characterize material microstructure in three dimensions at a micron level spatial resolution. While commercially available laboratory scale instrumentation is available, we focus our attention on synchrotron-based systems, where we can exploit a high flux, monochromatic X-ray beam to produce high fidelity three-dimensional images. A brief description of the physics and the mathematical analysis behind the technique is followed by example applications to specific materials characterization problems, with a particular focus on the utilization of three-dimensional image processing that can be used to extract a wide range of useful information.

  5. X-ray beam finder

    DOE Patents [OSTI]

    Gilbert, H.W.

    1983-06-16

    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.

  6. Evolution of titania nanotubes-supported WO{sub x} species by in situ thermo-Raman spectroscopy, X-ray diffraction and high resolution transmission electron microscopy

    SciTech Connect (OSTI)

    Cortes-Jacome, M.A.; Angeles-Chavez, C.; Morales, M.; Lopez-Salinas, E.; Toledo-Antonio, J.A.

    2007-10-15

    Structural evolution of WO{sub x} species on the surface of titania nanotubes was followed by in situ thermo-Raman spectroscopy. A total of 15 wt% of W atoms were loaded on the surface of a hydroxylated titania nanotubes by impregnation with ammonium metatungstate solution and then, the sample was thermally treated in a Linkam cell at different temperatures in nitrogen flow. The band characteristic of the W=O bond was observed at 962 cm{sup -1} in the dried sample, which vanished between 300 and 700 deg. C, and reappear again after annealing at 800 deg. C, along with a broad band centered at 935 cm{sup -1}, attributed to the v{sub 1} vibration of W=O in tetrahedral coordination. At 900 and 1000 deg. C, the broad band decomposed into four bands at 923, 934, 940 and 950 cm{sup -1}, corresponding to the symmetric and asymmetric vibration of W=O bonds in Na{sub 2}WO{sub 4} and Na{sub 2}W{sub 2}O{sub 7} phases as determined by X-ray diffraction and High resolution transmission electron microscopy (HRTEM). The structure of the nanotubular support was kept at temperatures below 450 deg. C, thereafter, it transformed into anatase being stabilized at temperatures as high as 900 deg. C. At 1000 deg. C, anatase phase partially converted into rutile. After annealing at 1000 deg. C, a core-shell model material was obtained, with a shell of ca. 5 nm thickness, composed of sodium tungstate nanoclusters, and a core composed mainly of rutile TiO{sub 2} phase. - Graphical abstract: Titania nanotubes loaded with 15 wt% W atoms were characterized from room temperature (rt) to 1000 deg. C by thermo-Raman spectroscopy in N{sub 2}. At 1000 deg. C, a core-shell model material was obtained, with a shell thickness of ca. 5 nm composed by nanoclusters of sodium tungstate, and a core composed mainly of rutile TiO{sub 2} phase.

  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)

    2014-11-15

    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. Comparison of galaxy clusters selected by weak-lensing, optical spectroscopy, and X-rays in the deep lens survey F2 field

    SciTech Connect (OSTI)

    Starikova, Svetlana; Jones, Christine; Forman, William R.; Vikhlinin, Alexey; Kurtz, Michael J.; Fabricant, Daniel G.; Murray, Stephen S.; Geller, Margaret J.; Dell'Antonio, Ian P.

    2014-05-10

    We compare galaxy clusters selected in Chandra and XMM-Newton X-ray observations of the 4 deg{sup 2} Deep Lens Survey (DLS) F2 field to the cluster samples previously selected in the same field from a sensitive weak-lensing shear map derived from the DLS and from a detailed galaxy redshift surveythe Smithsonian Hectospec Lensing Survey (SHELS). Our Chandra and XMM-Newton observations cover 1.6 deg{sup 2} of the DLS F2 field, including all 12 weak-lensing peaks above a signal-to-noise ratio of 3.5, along with 16 of the 20 SHELS clusters with published velocity dispersions >500 km s{sup 1}. We detect 26 extended X-ray sources in this area and confirm 23 of them as galaxy clusters using the optical imaging. Approximately 75% of clusters detected in either X-ray or spectroscopic surveys are found in both; these follow the previously established scaling relations between velocity dispersion, L {sub X}, and T {sub X}. A lower percentage, 60%, of clusters are in common between X-ray and DLS samples. With the exception of a high false-positive rate in the DLS weak-lensing search (5 out of 12 DLS candidates appear to be false), differences between the three cluster detection methods can be attributed primarily to observational uncertainties and intrinsic scatter between different observables and cluster mass.

  9. Spatiotemporal Monte Carlo transport methods in x-ray semiconductor detectors: Application to pulse-height spectroscopy in a-Se

    SciTech Connect (OSTI)

    Fang Yuan; Badal, Andreu; Allec, Nicholas; Karim, Karim S.; Badano, Aldo

    2012-01-15

    Purpose: The authors describe a detailed Monte Carlo (MC) method for the coupled transport of ionizing particles and charge carriers in amorphous selenium (a-Se) semiconductor x-ray detectors, and model the effect of statistical variations on the detected signal. Methods: A detailed transport code was developed for modeling the signal formation process in semiconductor x-ray detectors. The charge transport routines include three-dimensional spatial and temporal models of electron-hole pair transport taking into account recombination and trapping. Many electron-hole pairs are created simultaneously in bursts from energy deposition events. Carrier transport processes include drift due to external field and Coulombic interactions, and diffusion due to Brownian motion. Results: Pulse-height spectra (PHS) have been simulated with different transport conditions for a range of monoenergetic incident x-ray energies and mammography radiation beam qualities. Two methods for calculating Swank factors from simulated PHS are shown, one using the entire PHS distribution, and the other using the photopeak. The latter ignores contributions from Compton scattering and K-fluorescence. Comparisons differ by approximately 2% between experimental measurements and simulations. Conclusions: The a-Se x-ray detector PHS responses simulated in this work include three-dimensional spatial and temporal transport of electron-hole pairs. These PHS were used to calculate the Swank factor and compare it with experimental measurements. The Swank factor was shown to be a function of x-ray energy and applied electric field. Trapping and recombination models are all shown to affect the Swank factor.

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

    SciTech Connect (OSTI)

    Zanni, Martin T.

    1999-12-17

    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.

  11. Surface electronic structure of GaAs(110) studied by Auger photoelectron coincidence spectroscopy

    SciTech Connect (OSTI)

    Bartynski, R.A.; Garrison, K.; Jensen, E.; Hulbert, S.L.; Weinert, M.

    1990-12-31

    We have used Auger photoelectron coincidence spectroscopy to study the M{sub 4,5}VV Auger spectra of GaAs(110). Using this technique, the Ga and As spectra can be separated and studied independently. The lineshape of the As-M{sub 4,5}VV measured in coincidence with the As 3d photoemission line differs significantly from the conventional Auger spectrum. We attribute this to the surface electronic properties of the system. In addition, we have found that the ss-component of the As spectrum is more intense than expected based on calculations using atomic matrix elements. The Ga-M{sub 4,5}VV spectrum, of which only the pp-component is observed, agrees well with that expected from an independent electron model. A first principles electronic structure calculation of a 5-layer GaAs(110) slab has been performed to aid in the interpretation of the Auger spectra.

  12. Surface electronic structure of GaAs(110) studied by Auger photoelectron coincidence spectroscopy

    SciTech Connect (OSTI)

    Bartynski, R.A.; Garrison, K. ); Jensen, E. . Dept. of Physics); Hulbert, S.L.; Weinert, M. )

    1990-01-01

    We have used Auger photoelectron coincidence spectroscopy to study the M{sub 4,5}VV Auger spectra of GaAs(110). Using this technique, the Ga and As spectra can be separated and studied independently. The lineshape of the As-M{sub 4,5}VV measured in coincidence with the As 3d photoemission line differs significantly from the conventional Auger spectrum. We attribute this to the surface electronic properties of the system. In addition, we have found that the ss-component of the As spectrum is more intense than expected based on calculations using atomic matrix elements. The Ga-M{sub 4,5}VV spectrum, of which only the pp-component is observed, agrees well with that expected from an independent electron model. A first principles electronic structure calculation of a 5-layer GaAs(110) slab has been performed to aid in the interpretation of the Auger spectra.

  13. X-ray position detector and implementation in a mirror pointing servo system

    DOE Patents [OSTI]

    Rabedeau, Thomas A.; Van Campen, Douglas G.; Stefan, Peter M.

    2016-04-05

    An X-ray beam position and stability detector is provided having a first metal blade collinear with a second metal blade, where an edge of the first metal blade is opposite an edge of the second metal blade, where the first metal blade edge and the second metal blade edge are disposed along a centerline with respect to each other, where the metal blades are capable of photoelectron emission when exposed to an x-ray beam, a metal coating on the metal blades that is capable of enhancing the photoelectron emission, or suppressing energy-resonant contaminants, or enhancing the photoelectron emission and suppressing energy-resonant contaminants, a background shielding element having an electrode capable of suppressing photoelectron emission from spurious x-rays not contained in an x-ray beam of interest, and a photoelectron emission detector having an amplifier capable of detecting the photoelectron emission as a current signal.

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

    SciTech Connect (OSTI)

    Arnold, D.W.

    1994-08-01

    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.

  15. Tunable X-ray source

    DOE Patents [OSTI]

    Boyce, James R.

    2011-02-08

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

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

    SciTech Connect (OSTI)

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

    2014-11-15

    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.

  17. Photoelectronic characterization of heterointerfaces.

    SciTech Connect (OSTI)

    Brumbach, Michael Todd

    2012-02-01

    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.

  18. X-ray lithography source

    DOE Patents [OSTI]

    Piestrup, Melvin A.; Boyers, David G.; Pincus, Cary

    1991-01-01

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

  19. X-ray lithography source

    DOE Patents [OSTI]

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

    1991-12-31

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

  20. 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.

    2012-05-17

    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 ?.

  1. Soft X-ray absorption spectroscopy of La{sub 0.7}Ca{sub 0.3}Mn{sub 1−X}Al{sub X}O{sub 3} thin films

    SciTech Connect (OSTI)

    Kumar, Manish Choudhary, R. J. Phase, D. M.

    2014-04-24

    Epitaxial thin films of rare earth manganites have generated much attention recently due to their rich phase diagram. The electronic structure of these films is playing a very crucial role and demands a fundamental understanding prior to device fabrication. We have investigated the electronic structure of La{sub 0.7}Ca{sub 0.3}Mn{sub 1−X}Al{sub X}O{sub 3} (X=0, 0.15) epitaxial thin films by soft X-ray absorption spectroscopy technique using the surface sensitive total electron yield (TEY) mode.

  2. In situ soft X-ray absorption spectroscopy investigation of electrochemical corrosion of copper in aqueous NaHCO3 solution

    SciTech Connect (OSTI)

    Jiang, Peng; Chen, Jeng-Lung; Borondics, Ferenc; Glans, Per-Anders; West, Mark W.; Chang, Ching-Lin; Salmeron, Miquel; Guo, Jinghua

    2010-03-31

    A novel electrochemical setup has been developed for soft x-ray absorption studies of the electronic structure of electrode materials during electrochemical cycling. In this communication we illustrate the operation of the cell with a study of the corrosion behavior of copper in aqueous NaHCO3 solution via the electrochemically induced changes of its electronic structure. This development opens the way for in situ investigations of electrochemical processes, photovoltaics, batteries, fuel cells, water splitting, corrosion, electrodeposition, and a variety of important biological processes.

  3. Broadband high resolution X-ray spectral analyzer

    DOE Patents [OSTI]

    Silver, Eric H.; Legros, Mark; Madden, Norm W.; Goulding, Fred; Landis, Don

    1998-01-01

    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.

  4. Broadband high resolution X-ray spectral analyzer

    DOE Patents [OSTI]

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

    1998-07-07

    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.

  5. Miniature x-ray source

    DOE Patents [OSTI]

    Trebes, James E.; Stone, Gary F.; Bell, Perry M.; Robinson, Ronald B.; Chornenky, Victor I.

    2002-01-01

    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.

  6. X-ray magnetic spectroscopy of MBE-grown Mn-doped Bi{sub 2}Se{sub 3} thin films

    SciTech Connect (OSTI)

    Collins-McIntyre, L. J.; Watson, M. D.; Zhang, S. L.; Coldea, A. I.; Hesjedal, T.; Baker, A. A.; Harrison, S. E.; Pushp, A.; Kellock, A. J.; Parkin, S. S. P.; Laan, G. van der

    2014-12-15

    We report the growth of Mn-doped Bi{sub 2}Se{sub 3} thin films by molecular beam epitaxy (MBE), investigated by x-ray diffraction (XRD), atomic force microscopy (AFM), SQUID magnetometry and x-ray magnetic circular dichroism (XMCD). Epitaxial films were deposited on c-plane sapphire substrates by co-evaporation. The films exhibit a spiral growth mechanism typical of this material class, as revealed by AFM. The XRD measurements demonstrate a good crystalline structure which is retained upon doping up to ?7.5 atomic-% Mn, determined by Rutherford backscattering spectrometry (RBS), and show no evidence of the formation of parasitic phases. However an increasing interstitial incorporation of Mn is observed with increasing doping concentration. A magnetic moment of 5.1 ?{sub B}/Mn is obtained from bulk-sensitive SQUID measurements, and a much lower moment of 1.6 ?{sub B}/Mn from surface-sensitive XMCD. At ?2.5 K, XMCD at the Mn L{sub 2,3} edge, reveals short-range magnetic order in the films and indicates ferromagnetic order below 1.5 K.

  7. X-Ray Science Education

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

    TV Network external link DNA Interactive external link Reciprocal Net external link X-ray Science Courses and Programs Various educational efforts are closely related to the...

  8. Resonant Soft X-Ray Scattering - Combining Structural with Spectroscop...

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

    28, 2012 - 10:00am SLAC, Bldg. 137, Room 322 SSRL Presents Kevin Stone X-ray absorption spectroscopy has become an important tool in understanding the electronic structure...

  9. Photoelectron Spectroscopy and Theoretical Studies of Anion-pi Interactions: Binding Strength and Anion Specificity

    SciTech Connect (OSTI)

    Zhang, Jian; Zhou, Bin; Sun, Zhenrong; Wang, Xue B.

    2015-01-01

    Proposed in theory and confirmed to exist, anion? interactions have been recognized as new and important non-covalent binding forces. Despite extensive theoretical studies, numerous crystal structural identifications, and a plethora of solution phase investigations, intrinsic anion? interaction strengths that are free from complications of condensed phases environments, have not been directly measured in the gas phase. Herein we present a joint photoelectron spectroscopic and theoretical study on this subject, in which tetraoxacalix[2]arene[2]triazine 1, an electron-deficient and cavity self-tunable macrocyclic was used as a charge-neutral molecular host to probe its interactions with a series of anions with distinctly different shapes and charge states (spherical halides Cl?, Br?, I?, linear thiocyanate SCN?, trigonal planar nitrate NO??, pyramidic iodate IO??, and tetrahedral sulfate SO??). The binding energies of the resultant gaseous 1:1 complexes (1Cl?,1Br?, 1I?, 1SCN?, 1NO??, 1IO?? and 1SO??) were directly measured experimentally, exhibiting substantial non-covalent interactions with pronounced anion specific effects. The binding strengths of Cl?, NO??, IO?? with 1 are found to be strongest among all singly charged anions, amounting to ca. 30 kcal/mol, but only about 40% of that between 1 and SO??. Quantum chemical calculations reveal that all anions reside in the center of the cavity of 1 with anion? binding motif in the complexes optimized structures, where 1 is seen to be able to self-regulate its cavity structure to accommodate anions of different geometries and three-dimensional shapes. Electron density surface and natural bond orbital charge distribution analysis further support anion? binding formation. The calculated binding energies of the anions and 1 nicely reproduce the experimentally estimated electron binding energy increase. This work illustrates that size-selective photoelectron spectroscopy combined with theoretical calculations represent a powerful technique to probe intrinsic anion? interactions and has potential to provide quantitative guest-host molecular binding strengths and unravel fundamental insights in specific anion recognitions.

  10. 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.; Kontar, Eduard P.

    2013-05-10

    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.

  11. Synchrotron-based double imaging photoelectron/photoion coincidence spectroscopy of radicals produced in a flow tube: OH and OD

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

    Garcia, Gustavo A.; Tang, Xiaofeng; Gil, Jean -François; Nahon, Laurent; Ward, Michael; Batut, Sebastien; Fittschen, Christa; Taatjes, Craig A.; Osborn, David L.; Loison, Jean -Christophe

    2015-04-23

    In this study, we present a microwave discharge flow tube coupled with a double imaging electron/ion coincidence device and vacuum ultraviolet (VUV) synchrotron radiation. The system has been applied to the study of the photoelectron spectroscopy of the well-known radicals OH and OD. The coincidence imaging scheme provides a high selectivity and yields the spectra of the pure radicals, removing the ever-present contributions from excess reactants, background, or secondary products, and therefore obviating the need for a prior knowledge of all possible byproducts. The photoelectron spectra encompassing the X3Σ– ground state of the OH+ and OD+ cations have been extractedmore » and the vibrational constants compared satisfactorily to existing literature values. Future advantages of this approach include measurement of high resolution VUV spectroscopy of radicals, their absolute photoionization cross section, and species/isomer identification in chemical reactions as a function of time.« less

  12. Synchrotron-based double imaging photoelectron/photoion coincidence spectroscopy of radicals produced in a flow tube: OH and OD

    SciTech Connect (OSTI)

    Garcia, Gustavo A.; Tang, Xiaofeng; Gil, Jean -François; Nahon, Laurent; Ward, Michael; Batut, Sebastien; Fittschen, Christa; Taatjes, Craig A.; Osborn, David L.; Loison, Jean -Christophe

    2015-04-23

    In this study, we present a microwave discharge flow tube coupled with a double imaging electron/ion coincidence device and vacuum ultraviolet (VUV) synchrotron radiation. The system has been applied to the study of the photoelectron spectroscopy of the well-known radicals OH and OD. The coincidence imaging scheme provides a high selectivity and yields the spectra of the pure radicals, removing the ever-present contributions from excess reactants, background, or secondary products, and therefore obviating the need for a prior knowledge of all possible byproducts. The photoelectron spectra encompassing the X3? ground state of the OH+ and OD+ cations have been extracted and the vibrational constants compared satisfactorily to existing literature values. Future advantages of this approach include measurement of high resolution VUV spectroscopy of radicals, their absolute photoionization cross section, and species/isomer identification in chemical reactions as a function of time.

  13. Synchrotron-based double imaging photoelectron/photoion coincidence spectroscopy of radicals produced in a flow tube: OH and OD

    SciTech Connect (OSTI)

    Garcia, Gustavo A.; Tang, Xiaofeng; Gil, Jean -François; Nahon, Laurent; Ward, Michael; Batut, Sebastien; Fittschen, Christa; Taatjes, Craig A.; Osborn, David L.; Loison, Jean -Christophe

    2015-04-23

    In this study, we present a microwave discharge flow tube coupled with a double imaging electron/ion coincidence device and vacuum ultraviolet (VUV) synchrotron radiation. The system has been applied to the study of the photoelectron spectroscopy of the well-known radicals OH and OD. The coincidence imaging scheme provides a high selectivity and yields the spectra of the pure radicals, removing the ever-present contributions from excess reactants, background, or secondary products, and therefore obviating the need for a prior knowledge of all possible byproducts. The photoelectron spectra encompassing the X3Σ ground state of the OH+ and OD+ cations have been extracted and the vibrational constants compared satisfactorily to existing literature values. Future advantages of this approach include measurement of high resolution VUV spectroscopy of radicals, their absolute photoionization cross section, and species/isomer identification in chemical reactions as a function of time.

  14. X-ray shearing interferometer

    DOE Patents [OSTI]

    Koch, Jeffrey A.

    2003-07-08

    An x-ray interferometer for analyzing high density plasmas and optically opaque materials includes a point-like x-ray source for providing a broadband x-ray source. The x-rays are directed through a target material and then are reflected by a high-quality ellipsoidally-bent imaging crystal to a diffraction grating disposed at 1.times. magnification. A spherically-bent imaging crystal is employed when the x-rays that are incident on the crystal surface are normal to that surface. The diffraction grating produces multiple beams which interfere with one another to produce an interference pattern which contains information about the target. A detector is disposed at the position of the image of the target produced by the interfering beams.

  15. Effect of Biogeochemical Redox Processes on the Fate and Transport of As and U at an Abandoned Uranium Mine Site: an X-ray Absorption Spectroscopy Study

    SciTech Connect (OSTI)

    Troyer, Lyndsay D.; Stone, James J.; Borch, Thomas

    2014-01-28

    Although As can occur in U ore at concentrations up to 10 wt-%, the fate and transport of both U and As at U mine tailings have not been previously investigated at a watershed scale. The major objective of this study was to determine primary chemical and physical processes contributing to transport of both U and As to a down gradient watershed at an abandoned U mine site in South Dakota. Uranium is primarily transported by erosion at the site, based on decreasing concentrations in sediment with distance from the tailings. equential extractions and U X-ray absorption near-edge fine structure (XANES) fitting indicate that U is immobilised in a near-source sedimentation pond both by prevention of sediment transport and by reduction of UVI to UIV. In contrast to U, subsequent release of As to the watershed takes place from the pond partially due to reductive dissolution of Fe oxy(hydr)oxides. However, As is immobilised by adsorption to clays and Fe oxy(hydr)oxides in oxic zones and by formation of Assulfide mineral phases in anoxic zones down gradient, indicated by sequential extractions and As XANES fitting. This study indicates that As should be considered during restoration of uranium mine sites in order to prevent transport.

  16. Exploring electronic structure through high-resolution hard x-ray

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

    spectroscopies | Stanford Synchrotron Radiation Lightsource Exploring electronic structure through high-resolution hard x-ray spectroscopies Tuesday, July 23, 2013 - 11:00am SLAC, Conference Room 137-322 Presented by Dimosthenis Sokaras, Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory Modern high brilliance beamlines coupled with recent advances in hard-x-ray optics are establishing high-resolution hard x-ray spectroscopies as a powerful analytical tool for

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

    SciTech Connect (OSTI)

    Greenblatt, B.J.

    1999-02-01

    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.

  18. New X-ray insight into oxygen intercalation in epitaxial graphene grown on 4H-SiC(0001)

    SciTech Connect (OSTI)

    Kowalski, G. Tokarczyk, M.; D?browski, P.; Ciepielewski, P.; Mo?d?onek, M.; Strupi?ski, W.; Baranowski, J. M.

    2015-03-14

    Efficient control of intercalation of epitaxial graphene by specific elements is a way to change properties of the graphene. Results of several experimental techniques, such as X-ray photoelectron spectroscopy, micro-Raman mapping, reflectivity, attenuated total reflection, X-ray diffraction, and X-ray reflectometry, gave a new insight into the intercalation of oxygen in the epitaxial graphene grown on 4H-SiC(0001). These results confirmed that oxygen intercalation decouples the graphene buffer layer from the 4H-SiC surface and converts it into the graphene layer. However, in contrast to the hydrogen intercalation, oxygen does not intercalate between carbon planes (in the case of few layer graphene) and the interlayer spacing stays constant at the level of 3.353.32?. Moreover, X-ray reflectometry showed the presence of an oxide layer having the thickness of about 0.8? underneath the graphene layers. Apart from the formation of the nonuniform thin oxide layer, generation of defects in graphene caused by oxygen was also evidenced. Last but not least, water islands underneath defected graphene regions in both intercalated and non-intercalated samples were most probably revealed. These water islands are formed in the case of all the samples stored under ambient laboratory conditions. Water islands can be removed from underneath the few layer graphene stacks by relevant thermal treatment or by UV illumination.

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

    SciTech Connect (OSTI)

    Tan, G.O.

    1993-06-01

    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.

  20. Miniature x-ray source

    DOE Patents [OSTI]

    Trebes, James E.; Bell, Perry M.; Robinson, Ronald B.

    2000-01-01

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

  1. Synchrotron X-ray diffraction and Raman spectroscopy of Ln{sub 3}NbO{sub 7} (Ln=La, Pr, Nd, Sm-Lu) ceramics obtained by molten-salt synthesis

    SciTech Connect (OSTI)

    Siqueira, K.P.F.; Soares, J.C.; Granado, E.; Bittar, E.M.; Paula, A.M. de; Moreira, R.L.; Dias, A.

    2014-01-15

    Ln{sub 3}NbO{sub 7} (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) ceramics were obtained by molten-salt synthesis and their structures were systematically investigated by synchrotron X-ray diffraction (SXRD), second harmonic generation (SHG) and Raman spectroscopy. It was observed that ceramics with the largest ionic radii (La, Pr, Nd) crystallized into the Pmcn space group, while the ceramics with intermediate ionic radii (Sm-Gd) exhibited a different crystal structure belonging to the Ccmm space group. For this last group of ceramics, this result was corroborated by SHG and Raman scattering and ruled out any possibility for the non-centrosymmetric C 222{sub 1} space group, solving a recent controversy in the literature. Finally, according to SXRD, Tb-Lu containing samples exhibited an average defect fluorite structure (Fm3{sup }m space group). Nonetheless, broad scattering at forbidden Bragg reflections indicates the presence of short-range domains with lower symmetry. Vibrational spectroscopy showed the presence of six Raman-active modes, inconsistent with the average cubic fluorite structure, and in line with the existence of lower-symmetry nano-domains immersed in the average fluorite structure of these ceramics. - Graphical abstract: Raman spectrum for Sm{sub 3}NbO{sub 7} ceramics showing their 27 phonon modes adjusted through Lorentzian lines. According to synchrotron X-ray diffraction and Raman scattering, this material belongs to the space group Cmcm. Display Omitted - Highlights: Ln{sub 3}NbO{sub 7} ceramics were obtained by molten-salt synthesis. SXRD, SHG and Raman scattering confirmed orthorhombic and cubic structures. Ccmm instead of C222{sub 1} is the correct structure for SmGd ceramics. Pmcn space group was confirmed for La-, Pr- and Nd-based ceramics. For TbLu ceramics, ordered domains of a pyrochlore structure were observed.

  2. CORONAL PROPERTIES OF THE SEYFERT 1.9 GALAXY MCG-05-23-016 DETERMINED FROM HARD X-RAY SPECTROSCOPY WITH NuSTAR

    SciTech Connect (OSTI)

    Balokovi?, M.; Harrison, F. A.; Esmerian, C. J.; Frst, F.; Walton, D. J.; Matt, G.; Marinucci, A.; Zoghbi, A.; Reynolds, C. S.; Ballantyne, D. R.; Boggs, S. E.; Craig, W. W.; Christensen, F. E.; Fabian, A. C.; Parker, M. L.; Hailey, C. J.; Stern, D.; Zhang, W. W.

    2015-02-10

    Measurements of the high-energy cut-off in the coronal continuum of active galactic nuclei have long been elusive for all but a small number of the brightest examples. We present a direct measurement of the cut-off energy in the nuclear continuum of the nearby Seyfert 1.9 galaxy MCG-05-23-016 with unprecedented precision. The high sensitivity of NuSTAR up to 79 keV allows us to clearly disentangle the spectral curvature of the primary continuum from that of its reflection component. Using a simple phenomenological model for the hard X-ray spectrum, we constrain the cut-off energy to 116{sub ?5}{sup +6} keV with 90% confidence. Testing for more complex models and nuisance parameters that could potentially influence the measurement, we find that the cut-off is detected robustly. We further use simple Comptonized plasma models to provide independent constraints for both the kinetic temperature of the electrons in the corona and its optical depth. At the 90% confidence level, we find kT{sub e} = 29 2 keV and ? {sub e} = 1.23 0.08 assuming a slab (disk-like) geometry, and kT{sub e} = 25 2 keV and ? {sub e} = 3.5 0.2 assuming a spherical geometry. Both geometries are found to fit the data equally well and their two principal physical parameters are correlated in both cases. With the optical depth in the ? {sub e} ? 1 regime, the data are pushing the currently available theoretical models of the Comptonized plasma to the limits of their validity. Since the spectral features and variability arising from the inner accretion disk have been observed previously in MCG-05-23-016, the inferred high optical depth implies that a spherical or disk-like corona cannot be homogeneous.

  3. X-Ray Interactions with Matter from the Center for X-Ray Optics...

    Office of Scientific and Technical Information (OSTI)

    X-Ray Interactions with Matter from the Center for X-Ray Optics (CXRO) Title: X-Ray Interactions with Matter from the Center for X-Ray Optics (CXRO) The primary interactions of ...

  4. Electromechanical x-ray generator

    DOE Patents [OSTI]

    Watson, Scott A; Platts, David; Sorensen, Eric B

    2016-05-03

    An electro-mechanical x-ray generator configured to obtain high-energy operation with favorable energy-weight scaling. The electro-mechanical x-ray generator may include a pair of capacitor plates. The capacitor plates may be charged to a predefined voltage and may be separated to generate higher voltages on the order of hundreds of kV in the AK gap. The high voltage may be generated in a vacuum tube.

  5. Lensless X-Ray Imaging in Reflection

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

    Lensless X-Ray Imaging in Reflection Lensless X-Ray Imaging in Reflection Print Wednesday, 26 October 2011 00:00 The advent of x-ray free-electron laser (XFEL) light sources has...

  6. X-Ray Microscopy | Argonne National Laboratory

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

    X-Ray Microscopy X-Ray Microscopy This group exploits the unique capabilities of hard X-ray microscopy to visualize and understand the structure and behavior of hybrid,...

  7. Hand-held X-Ray Fluorescence (XRF) | Open Energy Information

    Open Energy Info (EERE)

    Dispersive Spectroscopy (WDS) typically performed using a SEM or EPMA, and X-Ray Diffraction (XRD) analyses. Data Collection and Mapping 2-M Probe Survey Fault Mapping Field...

  8. Integrated X-Ray Reflectivity Measurements for Elliptically Curved PET

    Office of Scientific and Technical Information (OSTI)

    Crystals (Conference) | SciTech Connect Integrated X-Ray Reflectivity Measurements for Elliptically Curved PET Crystals Citation Details In-Document Search Title: Integrated X-Ray Reflectivity Measurements for Elliptically Curved PET Crystals Spectroscopy provides valuable information about the temperature and density of a compressed pellet in a plasma. Elliptically curved pentaerythritol (PET) crystals are used as components for spectrometers. Their elliptical geometry gives several

  9. Highly polarized emission in spin resolved photoelectron spectroscopy of alpha-Fe(001)/GaAs(001)

    SciTech Connect (OSTI)

    Tobin, James; Yu, Sung Woo; Morton, Simon; Waddill, George; Thompson, Jamie; Neal, James; Spangenberg, Matthais; Shen, T.H.

    2009-05-19

    Highly spin-polarized sources of electrons, Integrated into device design, remain of great interest to the spintronic and magneto-electronic device community Here, the growth of Fe upon GaAs(001) has been studied with photoelectron spectroscopy (PES), including Spin Resolved PES. Despite evidence of atomic level disorder such as intermixing, an over-layer with the spectroscopic signature of alpha-Fe(001), with a bcc real space ordering, Is obtained The results will be discussed in light of the possibility of using such films as a spin-polarized source in device applications.

  10. Dissociation of strong acid revisited: X-ray photoelectron spectroscop...

    Office of Scientific and Technical Information (OSTI)

    is a turnover to a more structured solvation shell, accompanied by an increase in hydrogen bonding between HNO3 and water. We suggest that the driving force behind the more...

  11. The Structure of Interfacial Water on Gold Electrodes Studied by X-ray

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

    Absorption Spectroscopy - Joint Center for Energy Storage Research October 23, 2014, Research Highlights The Structure of Interfacial Water on Gold Electrodes Studied by X-ray Absorption Spectroscopy Schematic representation of X-ray absorption measurements at the biased gold water interface. X-rays arrive from the left and transmit through a thin silicon nitride window plated with gold. Fluorescence provides information far from the interface while it was discovered that electron yield is

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

    DOE Patents [OSTI]

    Frank, Matthias; Mears, Carl A.; Labov, Simon E.; Hiller, Larry J.; Barfknecht, Andrew T.

    2003-03-04

    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.

  13. 2012 ELECTRONIC SPECTROSCOPY & DYNAMICS GORDON RESEARCH CONFERENCE, JULY 22-27, 2012

    SciTech Connect (OSTI)

    Kohler, Bern

    2012-07-27

    Topics covered in this GRC include high-resolution spectroscopy, coherent electronic energy transport in biology, excited state theory and dynamics, excitonics, electronic spectroscopy of cold and ultracold molecules, and the spectroscopy of nanostructures. Several sessions will highlight innovative techniques such as time-resolved x-ray spectroscopy, frequency combs, and liquid microjet photoelectron spectroscopy that have forged stimulating new connections between gas-phase and condensed-phase work.

  14. Note: A novel dual-channel time-of-flight mass spectrometer for photoelectron imaging spectroscopy

    SciTech Connect (OSTI)

    Qin Zhengbo; Wu Xia; Tang Zichao [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China)

    2013-06-15

    A novel dual-channel time-of-flight mass spectrometer (D-TOFMS) has been designed to select anions in the photoelectron imaging measurements. In this instrument, the radiation laser can be triggered precisely to overlap with the selected ion cloud at the first-order space focusing plane. Compared with that of the conventional single channel TOFMS, the in situ mass selection performance of D-TOFMS is significantly improved. Preliminary experiment results are presented for the mass-selected photodetachment spectrum of F{sup -} to demonstrate the capability of the instrument.

  15. Compact x-ray source and panel

    DOE Patents [OSTI]

    Sampayon, Stephen E.

    2008-02-12

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

  16. Focused X-ray source

    DOE Patents [OSTI]

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

    1990-08-21

    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.

  17. Focused X-ray source

    DOE Patents [OSTI]

    Piestrup, Melvin A.; Boyers, David G.; Pincus, Cary I.; Maccagno, Pierre

    1990-01-01

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

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

    SciTech Connect (OSTI)

    Owald, P.; Khler, M.; Hemberger, P.; Bodi, A.; Gerber, T.; Bierkandt, T.; Akyildiz, E.; Kasper, T.

    2014-02-15

    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.

  19. A computational study of x-ray emission from high-Z x-ray sources...

    Office of Scientific and Technical Information (OSTI)

    study of x-ray emission from high-Z x-ray sources on the National Ignition Facility laser Citation Details In-Document Search Title: A computational study of x-ray emission...

  20. Spectroscopy

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

    Spectroscopy Spectroscopy Print In spectroscopy experiments, a sample is illuminated with light and the various product particles (electrons, ions, or fluorescent photons) are detected and analyzed.The unifying feature is that some "property" of a material is measured as the x-ray (photon) energy is swept though a range of values. At the most basic level, one measures the absorption, transmission, or reflectivity of a sample as a function of photon energy. Probes that use the vacuum

  1. Order-disorder transition in the Nd{sub 2-y}Y{sub y}Zr{sub 2}O{sub 7} system: Probed by X-ray diffraction and Raman spectroscopy

    SciTech Connect (OSTI)

    Mandal, B.P.; Krishna, P.S.R.; Tyagi, A.K.

    2010-01-15

    A series of compositions having the general formula Nd{sub 2-y}Y{sub y}Zr{sub 2}O{sub 7} have been synthesized by heating of mixtures of oxides of the components cation and characterized by X-ray diffraction and Raman spectroscopy. Rietveld analysis on the XRD data of all the compositions has been performed which revealed a decrease in lattice parameter as a function of y in the series Nd{sub 2-y}Y{sub y}Zr{sub 2}O{sub 7} (y=0.0-0.8). Subsequently, a biphasic region starts which continues for y=1.2 and 1.6. The other end member, i.e. Y{sub 2}Zr{sub 2}O{sub 7} is found to be defect fluorite. On the other hand, Nd{sup 3+} has been used as surrogate material for Am{sup 3+}, which is a minor actinide found in spent nuclear fuel. In the pyrochlore range, the increasing trend of the x-parameter of 48f oxygen indicates the enhancement of disorder in the system. Raman spectroscopy has been employed to validate the data obtained from XRD. The involvement of 48f oxygen in disorder has also been verified by Raman spectroscopic investigation. - Graphical abstract: In Nd{sub 2-y}Y{sub y}Zr{sub 2}O{sub 7} series, the structure changes from pyrochlore to defect fluorite with increase in Y content in the series. The Raman spectra explicitly shows how the structural changes take place in the system.

  2. X-ray Imaging Workshop

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

    Imaging and Spectro-microscopy: the Present and the Future Stanford Synchrotron Radiation Laboratory October 8-9, 2002 Organizers: John Miao & Keith Hodgson A workshop on "X-ray Imaging and Spectro-microscopy: the Present and the Future" was held on October 8-9, 2002. This workshop, organized by John Miao (SSRL) and Keith Hodgson (SSRL) provided a forum to discuss the scientific applications of a variety of imaging and spectro-microscopic techniques, including photoemission

  3. Standing-wave excited soft x-ray photoemission microscopy: application to

    Office of Scientific and Technical Information (OSTI)

    Co microdot magnetic arrays (Journal Article) | SciTech Connect Standing-wave excited soft x-ray photoemission microscopy: application to Co microdot magnetic arrays Citation Details In-Document Search Title: Standing-wave excited soft x-ray photoemission microscopy: application to Co microdot magnetic arrays We demonstrate the addition of depth resolution to the usual two-dimensional images in photoelectron emission microscopy (PEEM), with application to a square array of circular magnetic

  4. Vibronic structure of VO{sub 2} probed by slow photoelectron velocity-map imaging spectroscopy

    SciTech Connect (OSTI)

    Kim, Jongjin B.; Weichman, Marissa L.; Neumark, Daniel M.

    2014-01-21

    We report high-resolution anion photoelectron spectra of vanadium dioxide (VO{sub 2}{sup −}) obtained by slow electron velocity-map imaging of trapped and cryogenically cooled anions. Vibrationally resolved spectra are obtained for photodetachment to the first three neutral electronic states, giving an electron affinity of 1.8357(5) eV for the X-tilde{sup 2} A{sub 1} ground state and term energies of 0.1845(8) eV and 0.8130(5) eV for the A-tilde{sup 2}B{sub 1} and B-tilde{sup 2}A{sub 1} excited states, respectively. The vibrational fundamentals ν{sub 1} and ν{sub 2} are obtained for all three states. Experimental assignments are confirmed by energies from electronic structure calculations and Franck-Condon spectral simulations. These simulations support assigning the anion ground state as the X-tilde{sup 3}B{sub 1} state. With this assignment, photodetachment to the B-tilde{sup 2}A{sub 1} state involves a nominally forbidden two-electron transition, suggesting extensive configuration interaction in neutral VO{sub 2}.

  5. Resonance photoelectron spectroscopy of TiX{sub 2} (X = S, Se, Te) titanium dichalcogenides

    SciTech Connect (OSTI)

    Shkvarin, A. S. Yarmoshenko, Yu. M.; Skorikov, N. A.; Yablonskikh, M. V.; Merentsov, A. I.; Shkvarina, E. G.; Titov, A. N.

    2012-11-15

    The photoelectron valence band spectra of TiS{sub 2}, TiSe{sub 2}, and TiTe{sub 2} dichalcogenides are investigated in the Ti 2p-3d resonance regime. Resonance bands in the vicinity of the Fermi energy are found for TiS{sub 2} and TiTe{sub 2}. The nature of these bands is analyzed based on model calculations of the density of electronic states in TiS{sub 2}, TiSe{sub 2}, and TiTe{sub 2} compounds intercalated by titanium atoms. Analysis of experimental data and their comparison with model calculations showed that these bands have different origins. It is found that the resonance enhancement of an additional band observed in TiS{sub 2} is explained by self-intercalation by titanium during the synthesis of this compound. The resonance enhancement in TiTe{sub 2} is caused by occupation of the 3d band in Ti.

  6. X-Ray Nanoimaging: Instruments and Methods

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

    X-Ray Nanoimaging: Instruments and Methods X-Ray Nanoimaging: Instruments and Methods Print To be held as part of SPIE. http://spie.org/OP318 August 28-29, 2013; San Diego, California, USA

  7. Producing X-rays at the APS

    ScienceCinema (OSTI)

    None

    2013-04-19

    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.

  8. 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...

  9. Lensless X-Ray Imaging in Reflection

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

    Lensless 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...

  10. Neutron and X-ray Scattering

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

    Neutron and X-ray Scattering Neutron and X-ray Scattering When used together, neutrons and high-energy x-rays provide a supremely powerful scientific tool for mining details about the structure of materials. Combining neutrons and high-energy x-rays to explore the frontiers of materials in extreme environments. Illuminating previously inaccessible time and spatial scales. Enabling in situ research to design, discover, and control materials. Get Expertise Donald Brown Email Pushing the limits of

  11. Lensless X-Ray Imaging in Reflection

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

    Lensless 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 combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging

  12. Lensless X-Ray Imaging in Reflection

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

    Lensless 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 combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging

  13. Phase-sensitive X-ray imager

    DOE Patents [OSTI]

    Baker, Kevin Louis

    2013-01-08

    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.

  14. SMB, X-ray Emission Spectroscopy

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

    scientific level of data acquisition and analysis by experienced staff personnel. Tsu-Chien Weng (Staff Scientist) Dimosthenis Sokaras (Staff Scientist) Matthew Latimer (Beamline...

  15. SMB, X-Ray Spectroscopy & Imaging

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

    to study spatial distribution of elements in biological samples such as brain tissue. ... User support is provided at the technical, engineering and scientific level of data ...

  16. Cryotomography x-ray microscopy state

    DOE Patents [OSTI]

    Le Gros, Mark; Larabell, Carolyn A.

    2010-10-26

    An x-ray microscope stage enables alignment of a sample about a rotation axis to enable three dimensional tomographic imaging of the sample using an x-ray microscope. A heat exchanger assembly provides cooled gas to a sample during x-ray microscopic imaging.

  17. Photoelectron Spectroscopy and Ab Initio Study of the Structure and Bonding in A17N- and A17N

    SciTech Connect (OSTI)

    Averkiev, Boris B.; Call, Seth; Boldyrev, Alexander I.; Wang, Leiming; Huang, Wei; Wang, Lai S.

    2008-03-06

    The electronic and geometrical structures of Al7N– are investigated using photoelectron spectroscopy and ab initio calculations. Photoelectron spectra of Al7N– have been obtained at three photon energies with seven resolved spectral features at 193 nm. The spectral features of Al7N– are relatively broad, in particular for the ground state transition, indicating a large geometrical change from the ground state of Al7N– to that of Al7N. The ground state vertical detachment energy is measured to be 2.71 eV, whereas only an upper limit of ~1.9 eV can be estimated for the ground state adiabatic detachment energy due to the broad detachment band. Global minimum searches for A7N– and Al7N are performed using several theoretical methods. Vertical electron detachment energies are calculated using three different methods for the lowest energy structure and compared with the experimental data. Excellent agreement is observed between the calculated results and the experimental data. The global minimum structure of Al7N– is found to possess C3v symmetry, which can be viewed as an Al atom capping a face of a N-centered Al6N octahedron. However, in the ground state of Al7N the capping Al atom pushes in to form a bond with the central N atom, significantly expanding the three neighboring Al atoms. Thus, even though Al7N still possesses C3v symmetry, it is better viewed as a N coordinated by seven Al atoms in a cage-like structure. The chemical bonding in Al7N– is discussed on the basis of molecular orbital and natural bond analyses.

  18. 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

    SciTech Connect (OSTI)

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

    2015-03-01

    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 λ-MnO2 transforming to β-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.

  19. 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

    2015-03-01

    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 λ-MnO2 transforming to β-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

  20. 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

    SciTech Connect (OSTI)

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

    2015-03-01

    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 25C-580C under helium atmosphere. Upon heating, the electrochemically delithiated LMO changed into Mn3O4 phase at around 250C. Formation of MnO with rocksalt structure started at 520C. 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.

  1. X-ray transmissive debris shield

    DOE Patents [OSTI]

    Spielman, R.B.

    1996-05-21

    An X-ray debris shield for use in X-ray lithography that is comprised of an X-ray window having a layer of low density foam exhibits increased longevity without a substantial increase in exposure time. The low density foam layer serves to absorb the debris emitted from the X-ray source and attenuate the shock to the window so as to reduce the chance of breakage. Because the foam is low density, the X-rays are hardly attenuated by the foam and thus the exposure time is not substantially increased.

  2. X-ray transmissive debris shield

    DOE Patents [OSTI]

    Spielman, Rick B.

    1996-01-01

    An X-ray debris shield for use in X-ray lithography that is comprised of an X-ray window having a layer of low density foam exhibits increased longevity without a substantial increase in exposure time. The low density foam layer serves to absorb the debris emitted from the X-ray source and attenuate the shock to the window so as to reduce the chance of breakage. Because the foam is low density, the X-rays are hardly attenuated by the foam and thus the exposure time is not substantially increased.

  3. X-ray lithography using holographic images

    DOE Patents [OSTI]

    Howells, Malcolm R.; Jacobsen, Chris

    1995-01-01

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

  4. Spectroscopy

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

    Spectroscopy Print In spectroscopy experiments, a sample is illuminated with light and the various product particles (electrons, ions, or fluorescent photons) are detected and analyzed.The unifying feature is that some "property" of a material is measured as the x-ray (photon) energy is swept though a range of values. At the most basic level, one measures the absorption, transmission, or reflectivity of a sample as a function of photon energy. Probes that use the vacuum ultraviolet

  5. Spectroscopy

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

    Spectroscopy Print In spectroscopy experiments, a sample is illuminated with light and the various product particles (electrons, ions, or fluorescent photons) are detected and analyzed.The unifying feature is that some "property" of a material is measured as the x-ray (photon) energy is swept though a range of values. At the most basic level, one measures the absorption, transmission, or reflectivity of a sample as a function of photon energy. Probes that use the vacuum ultraviolet

  6. Hard disk drive based microsecond x-ray chopper for characterization of ionization chambers and photodiodes

    SciTech Connect (OSTI)

    Mller, O. Ltzenkirchen-Hecht, D.; Frahm, R.

    2015-03-15

    A fast X-ray chopper capable of producing ms long X-ray pulses with a typical rise time of few ?s was realized. It is ideally suited to investigate the temporal response of X-ray detectors with response times of the order of ?s to ms, in particular, any kind of ionization chambers and large area photo diodes. The drive mechanism consists of a brushless DC motor and driver electronics from a common hard disk drive, keeping the cost at an absolute minimum. Due to its simple construction and small dimensions, this chopper operates at home lab based X-ray tubes and synchrotron radiation sources as well. The dynamics of the most important detectors used in time resolved X-ray absorption spectroscopy, namely, ionization chambers and Passivated Implanted Planar Silicon photodiodes, were investigated in detail. The results emphasize the applicability of this X-ray chopper.

  7. ESC FY2002 Annual Report: Synchrotron-Radiation-Based Photoelectron Spectroscopy at the Advanced Light Source

    SciTech Connect (OSTI)

    Tobin, J G; Chung, B W; Schulze, R K; Shuh, D K

    2002-10-04

    Despite recent intensive experimental effort, the electronic structure of Pu, particularly {delta}-Pu, remains ill defined. An evaluation of our previous synchrotron-radiation-based investigation of {alpha}-Pu and {delta}-Pu has lead to a new paradigm for the interpretation of photoemission spectra of U, Np, {alpha}-Pu, {delta}-Pu and Am. This approach is founded upon a model in which spin and spin-orbit splittings are included in the picture of the 5f states and upon the observation of chiral/spin-dependent effects in non-magnetic systems. By extending a quantitative model developed for the interpretation of core level spectroscopy in magnetic systems, it is possible to predict the contributions of the individual component states within the 5-f manifold. This has lead to a remarkable agreement between the results of the model and the previously collected spectra of U, Np, Pu and Am, particularly {delta}-Pu, and to a prediction of what we might expect to see in future spin-resolving experiments.

  8. 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

    2010-08-02

    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.

  9. Reactivity of Au nanoparticles supported over SiO2 and TiO2 studiedby ambient pressure photoelectron spectroscopy

    SciTech Connect (OSTI)

    Herranz, Tirma; Deng, Xingyi; Cabot, Andreu; Alivisatos, Paul; Liu, Zhi; Soler-Illia, Galo; Salmeron, Miquel

    2009-04-15

    The influence of the metal cluster size and the identity of the support on the reactivity of gold based catalysts have been studied in the CO oxidation reaction. To overcome the structural complexity of the supported catalysts, gold nanoparticles synthesized from colloidal chemistry with precisely controlled size have been used. Those particles were supported over SiO{sub 2} and TiO{sub 2} and their catalytic activity was measured in a flow reactor. The reaction rate was dependent on the particle size and the support, suggesting two reaction pathways in the CO oxidation reaction. In parallel, ambient pressure photoelectron spectroscopy (APPS) has been performed under reaction conditions using bidimensional model catalysts prepared upon supporting the Au nanoparticles over planar polycrystalline SiO{sub 2} and TiO{sub 2} thin films by means of the Langmuir-Blodgett (LB) technique to mimic the characteristic of the powder samples. In this way, the catalytically active surface was characterized under true reaction conditions, revealing that during CO oxidation gold remains in the metallic state.

  10. High speed x-ray beam chopper

    DOE Patents [OSTI]

    McPherson, Armon; Mills, Dennis M.

    2002-01-01

    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. X-ray transmissive debris shield

    DOE Patents [OSTI]

    Spielman, Rick B.

    1994-01-01

    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.

  12. X-ray microscopy. Beyond ensemble averages

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

    Ice, Gene E.; Budai, John D.

    2015-01-01

    This work exemplifies emerging tools to characterize local materials structure and dynamics, made possible by powerful X-ray synchrotron and transmission electron microscopy methods.

  13. X-ray microscopy. Beyond ensemble averages

    SciTech Connect (OSTI)

    Ice, Gene E.; Budai, John D.

    2015-06-23

    This work exemplifies emerging tools to characterize local materials structure and dynamics, made possible by powerful X-ray synchrotron and transmission electron microscopy methods.

  14. Lensless X-Ray Imaging in Reflection

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

    Lensless X-Ray Imaging in Reflection Lensless X-Ray 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 of lensless imaging. XFELs combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are

  15. 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 combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that

  16. 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 combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that

  17. Lensless X-Ray Imaging in Reflection

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

    demonstrate for the first time a lensless x-ray imaging technique involving holographic principles and carried out in reflection (as opposed to transmission) geometry. The...

  18. Compound refractive X-ray lens

    DOE Patents [OSTI]

    Nygren, David R.; Cahn, Robert; Cederstrom, Bjorn; Danielsson, Mats; Vestlund, Jonas

    2000-01-01

    An apparatus and method for focusing X-rays. In one embodiment, his invention is a commercial-grade compound refractive X-ray lens. The commercial-grade compound refractive X-ray lens includes a volume of low-Z material. The volume of low-Z material has a first surface which is adapted to receive X-rays of commercially-applicable power emitted from a commercial-grade X-ray source. The volume of low-Z material also has a second surface from which emerge the X-rays of commercially-applicable power which were received at the first surface. Additionally, the commercial-grade compound refractive X-ray lens includes a plurality of openings which are disposed between the first surface and the second surface. The plurality of openings are oriented such that the X-rays of commercially-applicable power which are received at the first surface, pass through the volume of low-Z material and through the plurality openings. In so doing, the X-rays which emerge from the second surface are refracted to a focal point.

  19. X-ray laser microscope apparatus

    DOE Patents [OSTI]

    Suckewer, Szymon; DiCicco, Darrell S.; Hirschberg, Joseph G.; Meixler, Lewis D.; Sathre, Robert; Skinner, Charles H.

    1990-01-01

    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.

  20. SSRL School 2008 on Hard X-ray Scattering Techniques in MES

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

    May 20-22, 2008 SSRL School on Synchrotron X-ray Absorption Spectroscopy Techniques in Environmental and Materials Sciences: Theory and Application Group photo from the 2008 SSRL...

  1. Reabsorption of Soft X-Ray Emission at High X-Ray Free-Electron Laser

    Office of Scientific and Technical Information (OSTI)

    Fluences (Journal Article) | SciTech Connect Journal Article: Reabsorption of Soft X-Ray Emission at High X-Ray Free-Electron Laser Fluences Citation Details In-Document Search Title: Reabsorption of Soft X-Ray Emission at High X-Ray Free-Electron Laser Fluences Authors: Schreck, Simon ; Beye, Martin ; Sellberg, Jonas A. ; McQueen, Trevor ; Laksmono, Hartawan ; Kennedy, Brian ; Eckert, Sebastian ; Schlesinger, Daniel ; Nordlund, Dennis ; Ogasawara, Hirohito ; Sierra, Raymond G. ; Segtnan,

  2. Phased Contrast X-Ray Imaging

    ScienceCinema (OSTI)

    Erin Miller

    2012-12-31

    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.

  3. X-ray image intensifier phosphor

    DOE Patents [OSTI]

    D'Silva, A.P.; Fassel, V.A.

    1975-12-01

    Y/sub 1-x/Gd/sub x/.PO$sub 4$:Tb$sup 3+$ is an effective phosphor for use in X-ray intensifier screens and in nuclear radiation detection systems.

  4. Femtosecond X-ray protein nanocrystallography

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

    Femtosecond X-ray protein nanocrystallography Authors: Chapman, H.N., Fromme, P., Barty, A., White, T.A., Kirian, R.A., Aquila, A., Hunter, M.S., Schulz, J., DePonte, D.P.,...

  5. X-Ray Nanoimaging: Instruments and Methods

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

    X-Ray Nanoimaging: Instruments and Methods To be held as part of SPIE. http://spie.org/OP318 August 28-29, 2013; San Diego, California, USA

  6. Small Angle X-Ray Scattering Detector

    DOE Patents [OSTI]

    Hessler, Jan P.

    2004-06-15

    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.

  7. X-ray grid-detector apparatus

    DOE Patents [OSTI]

    Boone, John M.; Lane, Stephen M.

    1998-01-27

    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.

  8. X-ray source for mammography

    DOE Patents [OSTI]

    Logan, C.M.

    1994-12-20

    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.

  9. Lensless X-Ray Imaging in Reflection

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

    be reconstructed by a single Fourier transform; this is known as Fourier transform holography. The problem of getting sufficiently coherent x-rays onto and off of the sample in a...

  10. X-ray source for mammography

    DOE Patents [OSTI]

    Logan, Clinton M.

    1994-01-01

    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 Nanoimaging: Instruments and Methods

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

    X-Ray Nanoimaging: Instruments and Methods To be held as part of SPIE. http:spie.orgOP318 August 28-29, 2013; San Diego, California, USA...

  12. Biological Imaging by Soft X-Ray Diffraction Microscopy

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

    Biological Imaging by Soft X-Ray Diffraction Microscopy Biological Imaging by Soft X-Ray Diffraction Microscopy Print Wednesday, 30 November 2005 00:00 Electron and x-ray...

  13. Femtosecond Time-Delay X-ray Holography

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

    Time-Delay X-ray Holography X-ray free-electron lasers (XFELs) will produce photon pulses with a unique and desirable combination of properties. Their short X-ray wavelengths allow...

  14. Compton backscattered collimated x-ray source

    DOE Patents [OSTI]

    Ruth, R.D.; Huang, Z.

    1998-10-20

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

  15. Compton backscattered collimated x-ray source

    DOE Patents [OSTI]

    Ruth, Ronald D.; Huang, Zhirong

    1998-01-01

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

  16. Compton backscattered collmated X-ray source

    DOE Patents [OSTI]

    Ruth, Ronald D.; Huang, Zhirong

    2000-01-01

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

  17. 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)

    2013-12-15

    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.

  18. X-Ray Microcomputed Tomography for the Durability Characterization...

    Office of Scientific and Technical Information (OSTI)

    Conference: X-Ray Microcomputed Tomography for the Durability Characterization of Limestone Aggregate Citation Details In-Document Search Title: X-Ray Microcomputed Tomography for...

  19. X-Ray Characterization of Diesel Sprays | Department of Energy

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

    Sprays X-Ray Characterization of Diesel Sprays 2005 Diesel Engine Emissions Reduction ... More Documents & Publications X-Ray Characterization of Diesel Sprays and the Effects of ...

  20. Elemental and Chemically Specific X-ray Fluorescence Imaging...

    Office of Scientific and Technical Information (OSTI)

    Published Article: Elemental and Chemically Specific X-ray Fluorescence Imaging of Biological Systems Title: Elemental and Chemically Specific X-ray Fluorescence Imaging of ...

  1. Studies of magnetic microstructures with soft x-ray transmissionmicros...

    Office of Scientific and Technical Information (OSTI)

    Studies of magnetic microstructures with soft x-ray transmissionmicroscopy Citation Details In-Document Search Title: Studies of magnetic microstructures with soft x-ray ...

  2. Simultaneous cryo X-ray ptychographic and fluorescence microscopy...

    Office of Scientific and Technical Information (OSTI)

    Accepted Manuscript: Simultaneous cryo X-ray ptychographic and fluorescence microscopy of green algae Prev Next Title: Simultaneous cryo X-ray ptychographic and fluorescence ...

  3. Generation of Coherent X-Ray Radiation through Modulation Compression...

    Office of Scientific and Technical Information (OSTI)

    Generation of Coherent X-Ray Radiation through Modulation Compression Citation Details In-Document Search Title: Generation of Coherent X-Ray Radiation through Modulation Compression ...

  4. Direct synchrotron x-ray measurements of local strain fields...

    Office of Scientific and Technical Information (OSTI)

    Accepted Manuscript: Direct synchrotron x-ray measurements of local strain fields in ... September 3, 2016 Title: Direct synchrotron x-ray measurements of local strain fields in ...

  5. Experimental X-ray characterization of Gekko XII laser propagation...

    Office of Scientific and Technical Information (OSTI)

    Experimental X-ray characterization of Gekko XII laser propagation through very low ... Citation Details In-Document Search Title: Experimental X-ray characterization of Gekko ...

  6. Experimental X-ray characterization of Gekko XII laser propagation...

    Office of Scientific and Technical Information (OSTI)

    Experimental X-ray characterization of Gekko XII laser propagation through very low ... Title: Experimental X-ray characterization of Gekko XII laser propagation through very low ...

  7. Category:X-Ray Diffraction (XRD) | Open Energy Information

    Open Energy Info (EERE)

    X-Ray Diffraction (XRD) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the X-Ray Diffraction (XRD) page? For detailed information on...

  8. 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.

    1997-12-01

    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.

  9. Soft x-ray ionization induced fragmentation of glycine

    SciTech Connect (OSTI)

    Itl, E.; Kooser, K.; Rachlew, E.; Huels, M. A.; Kukk, E.

    2014-06-21

    X-ray absorption commonly involves dissociative core ionization producing not only momentum correlated charged fragments but also low- and high-energy electrons capable of inducing damage in living tissue. This gives a natural motivation for studying the core ionization induced fragmentation processes in biologically important molecules such as amino acids. Here the fragmentation of amino acid glycine following carbon 1s core ionization has been studied. Using photoelectron-photoion-photoion coincidence technique, a detailed analysis on fragmentation of the sample molecule into pairs of momentum correlated cations has been carried out. The main characteristics of core ionization induced fragmentation of glycine were found to be the rupture of the CC{sub ?} bond and the presence of the CNH{sub 2}{sup +} fragment.

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

    SciTech Connect (OSTI)

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

    2015-03-24

    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.

  11. 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.

    2015-03-24

    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.

  12. The Molecular Structure of Aqueous Hg(II)-EDTA As Determined by X-ray

    Office of Scientific and Technical Information (OSTI)

    Absorption Spectroscopy (Journal Article) | SciTech Connect SciTech Connect Search Results Journal Article: The Molecular Structure of Aqueous Hg(II)-EDTA As Determined by X-ray Absorption Spectroscopy Citation Details In-Document Search Title: The Molecular Structure of Aqueous Hg(II)-EDTA As Determined by X-ray Absorption Spectroscopy Authors: Thomas, Sara A. ; Gaillard, Jean-François [1] + Show Author Affiliations (NWU) Publication Date: 2015-08-24 OSTI Identifier: 1178839 Resource Type:

  13. X-ray lithography using holographic images

    DOE Patents [OSTI]

    Howells, M.S.; Jacobsen, C.

    1997-03-18

    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.

  14. X-ray lithography using holographic images

    DOE Patents [OSTI]

    Howells, Malcolm S.; Jacobsen, Chris

    1997-01-01

    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.

  15. Ultrafast X-Ray Coherent Control

    SciTech Connect (OSTI)

    Reis, David

    2009-05-01

    This main purpose of this grant was to develop the nascent #12;eld of ultrafast x-ray science using accelerator-based sources, and originally developed from an idea that a laser could modulate the di#11;racting properties of a x-ray di#11;racting crystal on a fast enough time scale to switch out in time a shorter slice from the already short x-ray pulses from a synchrotron. The research was carried out primarily at the Advanced Photon Source (APS) sector 7 at Argonne National Laboratory and the Sub-Picosecond Pulse Source (SPPS) at SLAC; in anticipation of the Linac Coherent Light Source (LCLS) x-ray free electron laser that became operational in 2009 at SLAC (all National User Facilities operated by BES). The research centered on the generation, control and measurement of atomic-scale dynamics in atomic, molecular optical and condensed matter systems with temporal and spatial resolution . It helped develop the ultrafast physics, techniques and scienti#12;c case for using the unprecedented characteristics of the LCLS. The project has been very successful with results have been disseminated widely and in top journals, have been well cited in the #12;eld, and have laid the foundation for many experiments being performed on the LCLS, the world's #12;rst hard x-ray free electron laser.

  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. PROPX: An X-ray Manipulation Program

    SciTech Connect (OSTI)

    Kyrala, G.A.

    1992-05-01

    An interactive micro-computer program that performs some manipulations on an input x-ray spectrum is introduced and described. The program is used to calculate the effect of absorption of filters, transmission through fibers, responsivity of photocathodes, responsivity of absorptive detectors, folding of responses, plotting of cross sections, and calculation, as a function of electron temperature, of the response due to a bremsstrahlung spectrum. Fluorescence from the targets is not included. Two different x-ray libraries are offered, one covers the x-ray range 30--10,000 eV with 288 energy points, and the other covers the energy range 10 eV to 1 MeV with 250 energy points per decade. 7 refs.

  18. Synchrotron x-ray photoemission study of soft x-ray processed ultrathin glycine-water ice films

    SciTech Connect (OSTI)

    Tzvetkov, George; Netzer, Falko P.

    2011-05-28

    Ultrathin glycine-water ice films have been prepared in ultrahigh vacuum by condensation of H{sub 2}O and glycine at 90 K on single crystalline alumina surfaces and processed by soft x-ray (610 eV) exposure for up to 60 min. The physicochemical changes in the films were monitored using synchrotron x-ray photoemission spectroscopy. Two films with different amounts of H{sub 2}O have been considered in order to evaluate the influence of the water ice content on the radiation-induced effects. The analysis of C1s, N1s, and O1s spectral regions together with the changes in the valence band spectra indicates that amino acid degradation occurs fast mainly via decarboxylation and deamination of pristine molecules. Enrichment of the x-ray exposed surfaces with fragments with carbon atoms without strong electronegative substituents (C-C and C-H) is documented as well. In the thinner glycine-water ice film (six layers of glycine + six layers of water) the 3D ice suffers strongly from the x-rays and is largely removed from the sample. The rate of photodecomposition of glycine in this film is about 30% higher than for glycine in the thicker film (6 layers of glycine + 60 layers of water). The photoemission results suggest that the destruction of amino acid molecules is caused by the direct interaction with the radiation and that no chemical attack of glycine by the species released by water radiolysis is detected.

  19. Reflection soft X-ray microscope and method

    DOE Patents [OSTI]

    Suckewer, Szymon; Skinner, Charles H.; Rosser, Roy

    1993-01-01

    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.

  20. Differential phase contrast X-ray imaging system and components

    DOE Patents [OSTI]

    Stutman, Daniel; Finkenthal, Michael

    2014-07-01

    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.

  1. Reflection soft X-ray microscope and method

    DOE Patents [OSTI]

    Suckewer, S.; Skinner, C.H.; Rosser, R.

    1993-01-05

    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.

  2. Energy resolved X-ray grating interferometry

    SciTech Connect (OSTI)

    Thuering, T.; Stampanoni, M.; Institute for Biomedical Engineering, Swiss Federal Institute of Technology, Zurich ; Barber, W. C.; Iwanczyk, J. S.; Seo, Y.; Alhassen, F.

    2013-05-13

    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.

  3. 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

    2013-02-01

    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.

  4. X-rays Illuminate Ancient Archimedes Text

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

    Related Links: May 2005 Headlines TIP Article Press Release Walters Art Museum SSRL Home Page SLAC Home Page Stanford Home Page Tuesday, 31 May 2005 X-rays Illuminate Ancient Archimedes Text (contact: Uwe Bergmann, bergmann@slac.stanford.edu) Archimedes Figure Image provided by Will Noel, The Walters Art Museum An early transcription of Archimedes' mathematical theories has been brought to light through the probing of high-intensity x-rays at SSRL's BL6-2. The text contains part of the Method of

  5. 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

    2011-01-12

    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.

  6. 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 M; Giglia, Angelo; Mahne, Nicola; Nannarone, Stefano

    2011-04-05

    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 is independent of the film thickness.

  7. Proposed new accelerator design for homeland security x-ray applications

    SciTech Connect (OSTI)

    Clayton, James; Shedlock, Daniel; Langeveld, Willem G.J.; Bharadwaj, Vinod; Nosochkov, Yuri

    2015-01-01

    Two goals for security scanning of cargo and freight are the ability to determine the type of material that is being imaged, and to do so at low radiation dose. One commonly used technique to determine the effective Z of the cargo is dual-energy imaging, i.e. imaging with different x-ray energy spectra. Another technique uses the fact that the transmitted x-ray spectrum itself also depends on the effective Z. Spectroscopy is difficult because the energy of individual x rays needs to be measured in a very high count-rate environment. Typical accelerators for security applications offer large but short bursts of x-rays, suitable for current-mode integrated imaging. In order to perform x-ray spectroscopy, a new accelerator design is desired that has the following features: 1) increased duty factor in order to spread out the arrival of x-rays at the detector array over time; 2) x-ray intensity modulation from one delivered pulse to the next by adjusting the accelerator electron beam instantaneous current so as to deliver adequate signal without saturating the spectroscopic detector; and 3) the capability to direct the (forward peaked) x-ray intensity towards high-attenuation areas in the cargo (fan-beam-steering). Current sources are capable of 0.1% duty factor, although usually they are operated at significantly lower duty factors (~0.04%), but duty factors in the range 0.4-1.0% are desired. The higher duty factor can be accomplished, e.g., by moving from 300 pulses per second (pps) to 1000 pps and/or increasing the pulse duration from a typical 4 ?s to 10 ?s. This paper describes initial R&D to examine cost effective modifications that could be performed on a typical accelerator for these purposes, as well as R&D for fan-beam steering.

  8. Applications of x-ray synchrotron radiation techniques to the study of dispersed electrocatalysts in high area materials

    SciTech Connect (OSTI)

    McBreen, J.

    1991-12-31

    This report discusses work demonstrating that X-Ray Absorption Spectroscopy is a very powerful technique for the study of electrocatalysts. Results for a prototech catalyst, and platinum are presented. (JL)

  9. Applications of x-ray synchrotron radiation techniques to the study of dispersed electrocatalysts in high area materials

    SciTech Connect (OSTI)

    McBreen, J.

    1991-01-01

    This report discusses work demonstrating that X-Ray Absorption Spectroscopy is a very powerful technique for the study of electrocatalysts. Results for a prototech catalyst, and platinum are presented. (JL)

  10. X-ray focal spot locating apparatus and method

    DOE Patents [OSTI]

    Gilbert, Hubert W.

    1985-07-30

    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.

  11. Multiple wavelength X-ray monochromators

    DOE Patents [OSTI]

    Steinmeyer, Peter A.

    1992-11-17

    An improved apparatus and method is provided for separating input x-ray radiation containing first and second x-ray wavelengths into spatially separate first and second output radiation which contain the first and second x-ray wavelengths, respectively. The apparatus includes a crystalline diffractor which includes a first set of parallel crystal planes, where each of the planes is spaced a predetermined first distance from one another. The crystalline diffractor also includes a second set of parallel crystal planes inclined at an angle with respect to the first set of crystal planes where each of the planes of the second set of parallel crystal planes is spaced a predetermined second distance from one another. In one embodiment, the crystalline diffractor is comprised of a single crystal. In a second embodiment, the crystalline diffractor is comprised of a stack of two crystals. In a third embodiment, the crystalline diffractor includes a single crystal that is bent for focussing the separate first and second output x-ray radiation wavelengths into separate focal points.

  12. Small Angle X-Ray Scattering Detector

    DOE Patents [OSTI]

    Hessler, Jan P.

    2004-06-15

    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., q.sub.max /q.sub.min.congruent.100.

  13. Multiple wavelength X-ray monochromators

    DOE Patents [OSTI]

    Steinmeyer, P.A.

    1992-11-17

    An improved apparatus and method is provided for separating input x-ray radiation containing first and second x-ray wavelengths into spatially separate first and second output radiation which contain the first and second x-ray wavelengths, respectively. The apparatus includes a crystalline diffractor which includes a first set of parallel crystal planes, where each of the planes is spaced a predetermined first distance from one another. The crystalline diffractor also includes a second set of parallel crystal planes inclined at an angle with respect to the first set of crystal planes where each of the planes of the second set of parallel crystal planes is spaced a predetermined second distance from one another. In one embodiment, the crystalline diffractor is comprised of a single crystal. In a second embodiment, the crystalline diffractor is comprised of a stack of two crystals. In a third embodiment, the crystalline diffractor includes a single crystal that is bent for focusing the separate first and second output x-ray radiation wavelengths into separate focal points. 3 figs.

  14. SLAC All Access: X-ray Microscope

    ScienceCinema (OSTI)

    Nelson, Johanna; Liu, Yijin

    2014-06-13

    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.

  15. Photoelectron spectroscopy and theoretical studies of gaseous uranium hexachlorides in different oxidation states: UCl{sub 6}{sup q?} (q = 02)

    SciTech Connect (OSTI)

    Su, Jing; Dau, Phuong D.; Huang, Dao-Ling; Wang, Lai-Sheng; Liu, Hong-Tao; Wei, Fan; Schwarz, W. H. E.; Li, Jun

    2015-04-07

    Uranium chlorides are important in actinide chemistry and nuclear industries, but their chemical bonding and many physical and chemical properties are not well understood yet. Here, we report the first experimental observation of two gaseous uranium hexachloride anions, UCl{sub 6}{sup ?} and UCl{sub 6}{sup 2?}, which are probed by photoelectron spectroscopy in conjunction with quantum chemistry calculations. The electron affinity of UCl{sub 6} is measured for the first time as +5.3 eV; its second electron affinity is measured to be +0.60 eV from the photoelectron spectra of UCl{sub 6}{sup 2?}. We observe that the detachment cross sections of the 5f electrons are extremely weak in the visible and UV energy ranges. It is found that the one-electron one-determinental molecular orbital picture and Koopmans theorem break down for the strongly internally correlated U-5f{sup 2} valence shell of tetravalent U{sup +4} in UCl{sub 6}{sup 2?}. The calculated adiabatic and vertical electron detachment energies from ab initio calculations agree well with the experimental observations. Electronic structure and chemical bonding in the uranium hexachloride species UCl{sub 6}{sup 2?} to UCl{sub 6} are discussed as a function of the oxidation state of U.

  16. Oxidized crystalline (3 1)-O surface phases of InAs and InSb studied by high-resolution photoelectron spectroscopy

    SciTech Connect (OSTI)

    Tuominen, M. E-mail: pekka.laukkanen@utu.fi; Lng, J.; Dahl, J.; Yasir, M.; Mkel, J.; Punkkinen, M. P. J.; Laukkanen, P. E-mail: pekka.laukkanen@utu.fi; Kokko, K.; Kuzmin, M.; Osiecki, J. R.; Schulte, K.

    2015-01-05

    The pre-oxidized crystalline (31)-O structure of InAs(100) has been recently found to significantly improve insulator/InAs junctions for devices, but the atomic structure and formation of this useful oxide layer are not well understood. We report high-resolution photoelectron spectroscopy analysis of (31)-O on InAs(100) and InSb(100). The findings reveal that the atomic structure of (31)-O consists of In atoms with unexpected negative (between ?0.64 and ?0.47?eV) and only moderate positive (In{sub 2}O type) core-level shifts; highly oxidized group-V sites; and four different oxygen sites. These fingerprint shifts are compared to those of previously studied oxides of III-V to elucidate oxidation processes.

  17. X-ray imaging crystal spectrometer for extended X-ray sources

    DOE Patents [OSTI]

    Bitter, Manfred L.; Fraenkel, Ben; Gorman, James L.; Hill, Kenneth W.; Roquemore, A. Lane; Stodiek, Wolfgang; von Goeler, Schweickhard E.

    2001-01-01

    Spherically or toroidally curved, double focusing crystals are used in a spectrometer for X-ray diagnostics of an extended X-ray source such as a hot plasma produced in a tokomak fusion experiment to provide spatially and temporally resolved data on plasma parameters using the imaging properties for Bragg angles near 45. For a Bragg angle of 45.degree., the spherical crystal focuses a bundle of near parallel X-rays (the cross section of which is determined by the cross section of the crystal) from the plasma to a point on a detector, with parallel rays inclined to the main plain of diffraction focused to different points on the detector. Thus, it is possible to radially image the plasma X-ray emission in different wavelengths simultaneously with a single crystal.

  18. A table-top femtosecond time-resolved soft x-ray transient absorption spectrometer

    SciTech Connect (OSTI)

    Leone, Stephen; Loh, Zhi-Heng; Khalil, Munira; Correa, Raoul E.; Leone, Stephen R.

    2008-05-21

    A laser-based, table-top instrument is constructed to perform femtosecond soft x-ray transient absorption spectroscopy. Ultrashort soft x-ray pulses produced via high-order harmonic generation of the amplified output of a femtosecond Ti:sapphire laser system are used to probe atomic core-level transient absorptions in atoms and molecules. The results provide chemically specific, time-resolved dynamics with sub-50-fs time resolution. In this setup, high-order harmonics generated in a Ne-filled capillary waveguide are refocused by a gold-coated toroidal mirror into the sample gas cell, where the soft x-ray light intersects with an optical pump pulse. The transmitted high-order harmonics are spectrally dispersed with a home-built soft x-ray spectrometer, which consists of a gold-coated toroidal mirror, a uniform-line spaced plane grating, and a soft x-ray CCD camera. The optical layout of the instrument, design of the soft x-ray spectrometer, and spatial and temporal characterization of the high-order harmonics are described. Examples of static and time-resolved photoabsorption spectra collected on this apparatus are presented.

  19. 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)

    2013-03-20

    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.

  20. Scanning Transmission X-ray Microscopy: Applications in Atmospheric Aerosol Research

    SciTech Connect (OSTI)

    Moffet, Ryan C.; Tivanski, Alexei V.; Gilles, Mary K.

    2011-01-20

    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.

  1. Rise Time Measurement for Ultrafast X-Ray Pulses

    DOE Patents [OSTI]

    Celliers, Peter M.; Weber, Franz A.; Moon, Stephen J.

    2005-04-05

    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. Rise time measurement for ultrafast X-ray pulses

    DOE Patents [OSTI]

    Celliers, Peter M.; Weber, Franz A.; Moon, Stephen J.

    2005-04-05

    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.

  3. X-ray microscopy at CNM | Argonne National Laboratory

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

    X-ray microscopy at CNM X-Ray Nanoprobe Beamline 1 of 5 X-Ray Nanoprobe Beamline Jörg Maser (left) and Robert Winarski, of Argonne's Center for Nanoscale Materials, X-Ray Microscopy Group, at the hard X-ray nanoprobe beamline on Advanced Photon Source (APS) Sector 26. The nanoprobe uses brilliant X-rays with photon energies from 3 to 30 keV to probe the properties of nanoscale materials with a spatial resolution of 30 nm. The system provides a combination of scanning-probe and full-field

  4. Interatomic scattering in energy dependent photoelectron spectra of Ar clusters

    SciTech Connect (OSTI)

    Patanen, M.; Benkoula, S.; Nicolas, C.; Goel, A.; Antonsson, E.; Neville, J. J.; Miron, C.

    2015-09-28

    Soft X-ray photoelectron spectra of Ar 2p levels of atomic argon and argon clusters are recorded over an extended range of photon energies. The Ar 2p intensity ratios between atomic argon and clusters’ surface and bulk components reveal oscillations similar to photoelectron extended X-ray absorption fine structure signal (PEXAFS). We demonstrate here that this technique allows us to analyze separately the PEXAFS signals from surface and bulk sites of free-standing, neutral clusters, revealing a bond contraction at the surface.

  5. Negative Ion Photoelectron Spectroscopy Confirms the Prediction that D-3h Carbontrioxide (CO3) Has a Singlet Ground State

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

    Hrovat, David; Hou, Gao-Lei; Chen, Bo; Wang, Xue B.; Borden, Weston

    2015-11-13

    The CO3 radical anion (CO3•–) has been formed by electrospraying carbonate dianion (CO32–) into the gas phase. The negative ion photoelectron (NIPE) spectrum of CO3•– shows that, unlike trimethylenemethane [C(CH2)3], carbontrioxide (CO3) has a singlet ground state. From the NIPE spectrum, the electron affinity of CO3 was determined to be EA = 4.06 ± 0.03 eV, and the singlet-triplet energy difference was found to be ΔEST = - 17.8 ± 0.9 kcal/mol. B3LYP, CCSD(T), and CASPT2 calculations all find that the two lowest triplet states of CO3 are very close in energy, a prediction that is confirmed by the relativemore » intensities of the bands in the NIPE spectrum of CO3•–. The 560 cm-1 vibrational progression, seen in the low energy region of the triplet band, enables the identification of the lowest, Jahn-Teller-distorted, triplet state as 3A1, in which both unpaired electrons reside in σ MOs, rather than 3A2, in which one unpaired electron occupies the b2 σ MO, and the other occupies the b1 π MO.« less

  6. THE ELECTRONIC STRUCTURE OF AG/CU(100) SURFACE ALLOYS STUDIES BY AUGER-PHOTOELECTRON COINCIDENCE SPECTROSCOPY.

    SciTech Connect (OSTI)

    ARENA,D.A.; BARTYNSKI,R.A.; HULBERT,S.L.

    2001-10-08

    We have measured the Ag and Pd M{sub 5}VV Auger spectrum in coincidence with Ag and Pd 4d{sub 5/2} photoelectrons for the Ag/Cu(100) and Pd/Cu(100) systems, respectively, as a function of admetal coverage. These systems form surface alloys (i.e. random substitutional alloys in the first atomic layer) for impurity concentrations in the 0.1 monolayer range. For these systems, the centroid of the impurity 4d levels is expected to shift away from the Fermi level by {approx}1 eV [Ruban et al., Journal of Molecular Catalysis. A 115 (1997) 421], an effect that should be easily seen in coincidence core-valence-valence Auger spectra. We find that the impurity Auger spectra of both systems shift in a manner that is consistent with d-band moving away from EF. However, the shift for Pd is considerably smaller than expected, and a shift almost absent for Ag. The disagreement between theory and experiment is most likely caused by the neglect of lattice relaxations in the calculations.

  7. X-ray radiography for container inspection

    DOE Patents [OSTI]

    Katz, Jonathan I.; Morris, Christopher L.

    2011-06-07

    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.

  8. Sample holder for X-ray diffractometry

    DOE Patents [OSTI]

    Hesch, Victor L.

    1992-01-01

    A sample holder for use with X-ray diffractometers with the capability to rotate the sample, as well as to adjust the position of the sample in the x, y, and z directions. Adjustment in the x direction is accomplished through loosening set screws, moving a platform, and retightening the set screws. Motion translators are used for adjustment in the y and z directions. An electric motor rotates the sample, and receives power from the diffractometer.

  9. Boron carbide coatings for neutron detection probed by x-rays, ions, and neutrons to determine thin film quality

    SciTech Connect (OSTI)

    Nowak, G. Strmer, M.; Horstmann, C.; Kampmann, R.; Hche, D.; Lorenz, U.; Mller, M.; Schreyer, A.; Becker, H.-W.; Haese-Seiller, M.; Moulin, J.-F.; Pomm, M.; Randau, C.; Hall-Wilton, R.

    2015-01-21

    Due to the present shortage of {sup 3}He and the associated tremendous increase of its price, the supply of large neutron detection systems with {sup 3}He becomes unaffordable. Alternative neutron detection concepts, therefore, have been invented based on solid {sup 10}B converters. These concepts require development in thin film deposition technique regarding high adhesion, thickness uniformity and chemical purity of the converter coating on large area substrates. We report on the sputter deposition of highly uniform large-area {sup 10}B{sub 4}C coatings of up to 2??m thickness with a thickness deviation below 4% using the Helmholtz-Zentrum Geesthacht large area sputtering system. The {sup 10}B{sub 4}C coatings are x-ray amorphous and highly adhesive to the substrate. Material analysis by means of X-ray-Photoelectron Spectroscopy, Secondary-Ion-Mass-Spectrometry, and Rutherford-Back-Scattering (RBS) revealed low impurities concentration in the coatings. The isotope composition determined by Secondary-Ion-Mass-Spectrometry, RBS, and inelastic nuclear reaction analysis of the converter coatings evidences almost identical {sup 10}B isotope contents in the sputter target and in the deposited coating. Neutron conversion and detection test measurements with variable irradiation geometry of the converter coating demonstrate an average relative quantum efficiency ranging from 65% to 90% for cold neutrons as compared to a black {sup 3}He-monitor. Thus, these converter coatings contribute to the development of {sup 3}He-free prototype detectors based on neutron grazing incidence. Transferring the developed coating process to an industrial scale sputtering system can make alternative {sup 3}He-free converter elements available for large area neutron detection systems.

  10. 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.

    2013-03-20

    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.

  11. Enabling X-ray free electron laser crystallography for challenging...

    Office of Scientific and Technical Information (OSTI)

    Enabling X-ray free electron laser crystallography for challenging biological systems from a limited number of crystals Citation Details In-Document Search Title: Enabling X-ray ...

  12. X-ray crystallographic analysis of adipocyte fatty acid binding...

    Office of Scientific and Technical Information (OSTI)

    X-ray crystallographic analysis of adipocyte fatty acid binding protein (aP2) modified with 4-hydroxy-2-nonenal Citation Details In-Document Search Title: X-ray crystallographic ...

  13. NIF and OMEGA X-Ray Environments Summary (Technical Report) ...

    Office of Scientific and Technical Information (OSTI)

    NIF and OMEGA X-Ray Environments Summary Citation Details In-Document Search Title: NIF and OMEGA X-Ray Environments Summary You are accessing a document from the Department of ...

  14. X-ray imaging of Nonlinear Resonant Gyrotropic Magnetic Vortex...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: X-ray imaging of Nonlinear Resonant Gyrotropic Magnetic Vortex Core Motion in Circular Permalloy Disks Citation Details In-Document Search Title: X-ray imaging of ...

  15. Sector 3 : High Resolution X-ray Scattering | Advanced Photon...

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

    & workshops IXN Group Useful Links Current APS status ESAF System GUP System X-Ray Science Division My APS Portal Sector 3 : High Resolution X-ray Scattering Sector 3 is...

  16. Inelastic X-ray and Nuclear Resonant Scattering | Advanced Photon...

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

    XSD-IXN XSD-IXN Home Staff Inelastic X-ray and Nuclear Resonant Scattering The Inelastic X-ray and Nuclear Resonant Scattering group operates beamlines at APS Sectors 3, 9 and 30....

  17. Using Light to Control How X Rays Interact with Matter

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

    that can be controlled by varying the properties of the optical control beam. Problems arise, however, when the probe pulse lies in the x-ray regime because x rays interact...

  18. Biological Imaging by Soft X-Ray Diffraction Microscopy

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

    Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in...

  19. X-Ray Diffraction Microscopy of Magnetic Structures

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

    X-Ray Diffraction Microscopy of Magnetic Structures Print science brief icon Scientists working at ALS Beamline 12.0.2.2 have demonstrated a new x-ray technique for producing...

  20. X-ray Science Division (XSD) | Advanced Photon Source

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

    XSD Groups XSD Safety and Training XSD Strategic Plan XSD Visitor Program XSD Intranet X-ray Science Division (XSD) XSD enables world-class research using x-rays by developing...

  1. ALS X-Rays Shine a New Light on Catalysis

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

    ALS X-Rays Shine a New Light on Catalysis ALS X-Rays Shine a New Light on Catalysis Print Thursday, 21 May 2015 11:16 Electrocatalysts are responsible for expediting reactions in...

  2. NIF and OMEGA X-Ray Environments Summary (Technical Report) ...

    Office of Scientific and Technical Information (OSTI)

    NIF and OMEGA X-Ray Environments Summary Citation Details In-Document Search Title: NIF and OMEGA X-Ray Environments Summary Abstract not provided. Authors: Fournier, K. B. 1 + ...

  3. Biological Imaging by Soft X-Ray Diffraction Microscopy

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

    Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations

  4. Biological Imaging by Soft X-Ray Diffraction Microscopy

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

    Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations

  5. X-Ray Diffraction Microscopy of Magnetic Structures

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

    X-Ray Diffraction Microscopy of Magnetic Structures Print science brief icon Scientists working at ALS Beamline 12.0.2.2 have demonstrated a new x-ray technique for producing short-exposure nanoscale images of the magnetic structure of materials. The new method combines aspects of coherent x-ray diffraction, which can determine 3-D charge distributions, and resonant magnetic scattering, which is sensitive to magnetic structures. Physicists have used coherent x-ray diffraction to measure the

  6. X-Ray Diffraction Microscopy of Magnetic Structures

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

    X-Ray Diffraction Microscopy of Magnetic Structures Print science brief icon Scientists working at ALS Beamline 12.0.2.2 have demonstrated a new x-ray technique for producing short-exposure nanoscale images of the magnetic structure of materials. The new method combines aspects of coherent x-ray diffraction, which can determine 3-D charge distributions, and resonant magnetic scattering, which is sensitive to magnetic structures. Physicists have used coherent x-ray diffraction to measure the

  7. X-Ray Diffraction Microscopy of Magnetic Structures

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

    X-Ray Diffraction Microscopy of Magnetic Structures Print science brief icon Scientists working at ALS Beamline 12.0.2.2 have demonstrated a new x-ray technique for producing short-exposure nanoscale images of the magnetic structure of materials. The new method combines aspects of coherent x-ray diffraction, which can determine 3-D charge distributions, and resonant magnetic scattering, which is sensitive to magnetic structures. Physicists have used coherent x-ray diffraction to measure the

  8. Biological Imaging by Soft X-Ray Diffraction Microscopy

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

    Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations

  9. Biological Imaging by Soft X-Ray Diffraction Microscopy

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

    Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations

  10. Biological Imaging by Soft X-Ray Diffraction Microscopy

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

    Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations

  11. Biological Imaging by Soft X-Ray Diffraction Microscopy

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

    Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations

  12. Biological Imaging by Soft X-Ray Diffraction Microscopy

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

    Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations

  13. 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

    2015-03-01

    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.

  14. 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.

  15. Femtosecond laser-electron x-ray source

    DOE Patents [OSTI]

    Hartemann, Frederic V.; Baldis, Hector A.; Barty, Chris P.; Gibson, David J.; Rupp, Bernhard

    2004-04-20

    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.

  16. X-Ray Imaging Crystal Spectrometer for Extended X-Ray Sources

    SciTech Connect (OSTI)

    Bitter, Manfred L.; Fraekel, Benjamin; Gorman, James L.; Hill, Kenneth W.; Roquemore, Lane A.; Stodiek, Wolfgang; Goeler, Schweickhard von

    1999-05-01

    Spherically or toroidally curved, double focusing crystals are used in a spectrometer for X-ray diagnostics of an extended X-ray source such as a hot plasma produced in a tokamak fusion experiment to provide spatially and temporally resolved data on plasma parameters such as ion temperature, toroidal and poloidal rotation, electron temperature, impurity ion charge-state distributions, and impurity transport. The imaging properties of these spherically or toroidally curved crystals provide both spectrally and spatially resolved X-ray data from the plasma using only one small spherically or toroidally curved crystal, thus eliminating the requirement for a large array of crystal spectrometers and the need to cross-calibrate the various crystals.

  17. Digital X-ray Pipe Inspector Software

    Energy Science and Technology Software Center (OSTI)

    2009-10-29

    The Digital X-ray Pipe Inspector software requires a digital x-ray image of a pipe as input to the program, such as the image in Attachment A Figure 1. The image may be in a variety of software formats such as bitmap, jpeg, tiff, DICOM or DICONDE. The software allows the user to interactively select a region of interest from the image for analysis. This software is used to analyze digital x-ray images of pipes tomore » evaluate loss of wall thickness. The software specifically provides tools to analyze the image in (a) the pipe walls, (b) between the pipe walls. Traditional software uses only the information at the pipe wall while this new software also evaluates the image between the pipewalls. This makes the inspection process faster, more thorough, more efficient, and reduces expensive reshots. Attachment A Figure 2 shows a region of interest (a green box) drawn by the user around an anomaly in the pipe wall. This area is automatically analyzed by the external pipe wall tool with the result shown in Attachment A Figure 3. The edges of the pipe wall are detected and highlighted in yellow and areas where the wall thickness in less the the minimum wall threshold are shown in red. These measurements are typically made manually in other software programs, which lead to errors and inconsistency because the location of the edges are estimated by the user. Attachment A Figure 4 shows a region of interest (a green box) drawn by the user between the pipe walls. As can be seen there are intensity anomalies that correspond to wall defects. However, this information is not used directly by other software programs. In order to fully investigate these anomalies, the pipe would be reinspected in a different orientation to attempt to obtain a view of the anomaly in the pipe wall rather than the interior of the pipe. The pipe may need to be x-rayed a number of times to obtain the correct orientation. This is very costly and time consuming. The new software can perform the analysis directly on the intensity information in the original image. Figures 5 through 9 in Attachment A show wall defects in red for various percents of wall thickness loss. For example, Figure 5 show defects (in red) where the wall thickness is 95% or less than the nominal wall thickness (or a 5% or greater wall thickness loss). Wall thicknesses can be given in absolute terms as well.« less

  18. Holographic Methods in X-ray Crystallography

    Energy Science and Technology Software Center (OSTI)

    1995-07-28

    The holographic method makes use of partially modeled electron density and experimentally-measured structure factor amplitudes to recover electron density corresponding to the unmodeled part of a crystal structure. This paper describes a fast algorithm that makes it possible to apply the holographic method to sizable crystallographic problems. The algorithm uses positivity constraints on the electron density, and can incorporate a target electron density, making it similar to solvent flattening. Using both synthetic and experimental data,more » we assess the potential for applying the holographic method to macromolecular x-ray crystallography.« less

  19. Subject: Ames Blue Alert - X-ray Shutter Maintenance

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

    Ames Blue Alert - X-ray Shutter Maintenance Statement: This lesson learned involves an Ames Laboratory x-ray system. Prior to starting x- ray experiments checking the operability of safety interlocks and x-ray shutter systems will decrease the likelihood of an unplanned exposure incident. Discussion: At the end of a sample run the shutter for an x-ray system at the Ames Laboratory did not close automatically as expected. The researcher followed the approved safety procedures and did not access

  20. Soft x-ray spectromicroscopy development for materials science at the Advanced Light Source

    SciTech Connect (OSTI)

    Warwick, T.; Padmore, H.; Ade, H.; Hitchcock, A.P.; Rightor, E.G.; Tonner, B.P.

    1996-08-01

    Several third generation synchrotron radiation facilities are now operational and the high brightness of these photon sources offers new opportunities for x-ray microscopy. Well developed synchrotron radiation spectroscopy techniques are being applied in new instruments capable of imaging the surface of a material with a spatial resolution smaller than one micron. There are two aspects to this. One is to further the field of surface science by exploring the effects of spatial variations across a surface on a scale not previously accessible to x-ray measurements. The other is to open up new analytical techniques in materials science using x-rays, on a spatial scale comparable to that of the processes or devices to be studied. The development of the spectromicroscopy program at the Advanced Light Source will employ a variety of instruments, some are already operational. Their development and use will be discussed, and recent results will be presented to illustrate their capabilities.

  1. In Situ X-Ray Probing Reveals Fingerprints of Surface Platinum Oxide

    SciTech Connect (OSTI)

    Friebel, Daniel

    2011-08-24

    In situ x-ray absorption spectroscopy (XAS) at the Pt L{sub 3} edge is a useful probe for Pt-O interactions at polymer electrolyte membrane fuel cell (PEMFC) cathodes. We show that XAS using the high energy resolution fluorescence detection (HERFD) mode, applied to a well-defined monolayer Pt/Rh(111) sample where the bulk penetrating hard x-rays probe only surface Pt atoms, provides a unique sensitivity to structure and chemical bonding at the Pt-electrolyte interface. Ab initio multiple-scattering calculations using the FEFF8 code and complementary extended x-ray absorption fine structure (EXAFS) results indicate that the commonly observed large increase of the white-line at high electrochemical potentials on PEMFC cathodes originates from platinum oxide formation, whereas previously proposed chemisorbed oxygen-containing species merely give rise to subtle spectral changes.

  2. Method and apparatus for analog signal conditioner for high speed, digital x-ray spectrometer

    DOE Patents [OSTI]

    Warburton, William K.; Hubbard, Bradley

    1999-01-01

    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.

  3. Method and apparatus for analog signal conditioner for high speed, digital x-ray spectrometer

    DOE Patents [OSTI]

    Warburton, W.K.; Hubbard, B.

    1999-02-09

    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 is disclosed. 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. 13 figs.

  4. Apparatus for monitoring X-ray beam alignment

    DOE Patents [OSTI]

    Steinmeyer, Peter A.

    1991-10-08

    A self-contained, hand-held apparatus is provided for minitoring 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.

  5. Apparatus for monitoring X-ray beam alignment

    DOE Patents [OSTI]

    Steinmeyer, P.A.

    1991-10-08

    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.

  6. Electronic states of thiophene/phenylene co-oligomers: Extreme-ultra violet excited photoelectron spectroscopy observations and density functional theory calculations

    SciTech Connect (OSTI)

    Kawaguchi, Yoshizo; Sasaki, Fumio; Mochizuki, Hiroyuki; Ishitsuka, Tomoaki; Tomie, Toshihisa; Ootsuka, Teruhisa; Watanabe, Shuji; Shimoi, Yukihiro; Yamao, Takeshi; Hotta, Shu

    2013-02-28

    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.

  7. 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

    2015-03-30

    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 fmore(Ce?) component. The spectral weight of f 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

  8. Electronic structure of the heavy-fermion caged compound Ce3Pd20X6(X=Si,Ge) studied by density functional theory and photoelectron spectroscopy

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

    Yamaoka, Hitoshi; Schwier, Eike F.; Arita, Masashi; Shimada, Kenya; Tsujii, Naohito; Jarrige, Ignace; Jiang, Jian; Hayashi, Hirokazu; Iwasawa, Hideaki; Namatame, Hirofumi; et al

    2015-03-30

    The electronic structure of Ce₃Pd₂₀X₆ (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 f⁰ (Ce⁴⁺) component with a small fraction of f¹more » (Ce³⁺) component. The spectral weight of f¹ component near the Fermi level Ce₃Pd₂₀Si₆ is stronger than that for Ce₃Pd₂₀Ge₆ 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 Ce₃Pd₂₀Si₆ compared to Ce₃Pd₂₀Ge₆.« less

  9. In situ synchrotron radiation photoelectron spectroscopy study of the oxidation of the Ge(100)-2 1 surface by supersonic molecular oxygen beams

    SciTech Connect (OSTI)

    Yoshigoe, Akitaka; Teraoka, Yuden; Okada, Ryuta; Yamada, Yoichi; Sasaki, Masahiro

    2014-11-07

    In situ synchrotron radiation photoelectron spectroscopy was performed during the oxidation of the Ge(100)-2 1 surface induced by a molecular oxygen beam with various incident energies up to 2.2 eV from the initial to saturation coverage of surface oxides. The saturation coverage of oxygen on the clean Ge(100) surface was much lower than one monolayer and the oxidation state of Ge was +2 at most. This indicates that the Ge(100) surface is so inert toward oxidation that complete oxidation cannot be achieved with only pure oxygen (O{sub 2}) gas, which is in strong contrast to Si surfaces. Two types of dissociative adsorption, trapping-mediated and direct dissociation, were confirmed by oxygen uptake measurements depending on the incident energy of O{sub 2}. The direct adsorption process can be activated by increasing the translational energy, resulting in an increased population of Ge{sup 2+} and a higher final oxygen coverage. We demonstrated that hyperthermal O{sub 2} beams remarkably promote the room-temperature oxidation with novel atomic configurations of oxides at the Ge(100) surface. Our findings will contribute to the fundamental understanding of oxygen adsorption processes at 300 K from the initial stages to saturated oxidation.

  10. The reaction mechanism of SnSb and Sb thin film anodes for Na-ion batteries studied by X-ray diffraction, 119Sn and 121Sb M ssbauer spectroscopies

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

    Baggetto, Loic; Hah, Hien-Yoong; Jumas, Dr. Jean-Claude; Johnson, Prof. Dr. Charles E.; Johnson, Jackie A.; Keum, Jong Kahk; Bridges, Craig A; Veith, Gabriel M

    2014-01-01

    The electrochemical reaction of Sb and SnSb anode materials with Na results in the formation of amorphous materials. To understand the resulting phases and electrochemical capacities we studied the reaction products local order using 119Sn and 121Sb M ssbauer spectroscopies in conjunction with measurements performed on model powder compounds of Na-Sn and Na-Sb to further clarify the reactions steps. For pure Sb the discharge (sodiation) starts with the formation of an amorphous phase composed of atomic environments similar to those found in NaSb, and proceeds further by the formation of environments similar to that present in Na3Sb. The reversible reactionmore » takes place during a large portion of the charge process. At full charge the anode material still contains a substantial fraction of Na, which explains the lack of recrystallization into crystalline Sb. The reaction of SnSb yields Na3Sb crystalline phase at full discharge at higher temperatures (65 and 95 C) while the room temperature reaction yields amorphous compounds. The electrochemically-driven, solid-state amorphization reaction occurring at room temperature is governed by the simultaneous formation of Na-coordinated Sn and Sb environments, as monitored by the decrease (increase) of the 119Sn (121Sb) M ssbauer isomer shifts. Overall, the monitoring of the hyperfine parameters enables to correlate the changes in Na content to the individual Sn and Sb local chemical environments.« less

  11. The reaction mechanism of SnSb and Sb thin film anodes for Na-ion batteries studied by X-ray diffraction, 119Sn and 121Sb Mössbauer spectroscopies

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

    Baggetto, Loïc; Hah, Hien-Yoong; Jumas, Jean-Claude; Johnson, Charles E.; Johnson, Jacqueline A.; Keum, Jong K.; Bridges, Craig A.; Veith, Gabriel M.

    2014-06-01

    The electrochemical reaction of Sb and SnSb anode materials with Na results in the formation of amorphous materials. To understand the resulting phases and electrochemical capacities we studied the reaction products local order using 119Sn and 121Sb Mössbauer spectroscopies in conjunction with measurements performed on model powder compounds of Na-Sn and Na-Sb to further clarify the reactions steps. For pure Sb the discharge (sodiation) starts with the formation of an amorphous phase composed of atomic environments similar to those found in NaSb, and proceeds further by the formation of environments similar to that present in Na3Sb. The reversible reaction takesmore » place during a large portion of the charge process. At full charge the anode material still contains a substantial fraction of Na, which explains the lack of recrystallization into crystalline Sb. The reaction of SnSb yields Na3Sb crystalline phase at full discharge at higher temperatures (65 and 95°C) while the room temperature reaction yields amorphous compounds. The electrochemically-driven, solid-state amorphization reaction occurring at room temperature is governed by the simultaneous formation of Na-coordinated Sn and Sb environments, as monitored by the decrease (increase) of the 119Sn (121Sb) Mössbauer isomer shifts. Overall, the monitoring of the hyperfine parameters enables to correlate the changes in Na content to the individual Sn and Sb local chemical environments.« less

  12. The reaction mechanism of SnSb and Sb thin film anodes for Na-ion batteries studied by X-ray diffraction, 119Sn and 121Sb Mössbauer spectroscopies

    SciTech Connect (OSTI)

    Baggetto, Loïc; Hah, Hien-Yoong; Jumas, Jean-Claude; Johnson, Charles E.; Johnson, Jacqueline A.; Keum, Jong K.; Bridges, Craig A.; Veith, Gabriel M.

    2014-06-01

    The electrochemical reaction of Sb and SnSb anode materials with Na results in the formation of amorphous materials. To understand the resulting phases and electrochemical capacities we studied the reaction products local order using 119Sn and 121Sb Mössbauer spectroscopies in conjunction with measurements performed on model powder compounds of Na-Sn and Na-Sb to further clarify the reactions steps. For pure Sb the discharge (sodiation) starts with the formation of an amorphous phase composed of atomic environments similar to those found in NaSb, and proceeds further by the formation of environments similar to that present in Na3Sb. The reversible reaction takes place during a large portion of the charge process. At full charge the anode material still contains a substantial fraction of Na, which explains the lack of recrystallization into crystalline Sb. The reaction of SnSb yields Na3Sb crystalline phase at full discharge at higher temperatures (65 and 95°C) while the room temperature reaction yields amorphous compounds. The electrochemically-driven, solid-state amorphization reaction occurring at room temperature is governed by the simultaneous formation of Na-coordinated Sn and Sb environments, as monitored by the decrease (increase) of the 119Sn (121Sb) Mössbauer isomer shifts. Overall, the monitoring of the hyperfine parameters enables to correlate the changes in Na content to the individual Sn and Sb local chemical environments.

  13. Gated monochromatic x-ray imager

    SciTech Connect (OSTI)

    Oertel, J.A.; Archuleta, T.; Clark, L.

    1995-09-01

    We have recently developed a gated monochromatic x-ray imaging diagnostic for the national Inertial-Confinement Fusion (ICF) program. This new imaging system will be one of the primary diagnostics to be utilized on University of Rochester`s Omega laser fusion facility. The new diagnostic is based upon a Kirkpatrick-Baez (KB) microscope dispersed by diffraction crystals, as first described by Marshall and Su. The dispersed images are gated by four individual proximity focused microchannel plates and recorded on film. Spectral coverage is tunable up to 8 keV, spectral resolution has been measured at 20 eV, temporal resolution is 80 ps, and spatial resolution is better than 10 {mu}m.

  14. Gray scale x-ray mask

    DOE Patents [OSTI]

    Morales, Alfredo M.; Gonzales, Marcela

    2006-03-07

    The present invention describes a method for fabricating an embossing tool or an x-ray mask tool, providing microstructures that smoothly vary in height from point-to-point in etched substrates, i.e., structure which can vary in all three dimensions. The process uses a lithographic technique to transfer an image pattern in the surface of a silicon wafer by exposing and developing the resist and then etching the silicon substrate. Importantly, the photoresist is variably exposed so that when developed some of the resist layer remains. The remaining undeveloped resist acts as an etchant barrier to the reactive plasma used to etch the silicon substrate and therefore provides the ability etch structures of variable depths.

  15. Proposed new accelerator design for homeland security x-ray applications

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

    Clayton, James; Shedlock, Daniel; Langeveld, Willem G.J.; Bharadwaj, Vinod; Nosochkov, Yuri

    2015-01-01

    Two goals for security scanning of cargo and freight are the ability to determine the type of material that is being imaged, and to do so at low radiation dose. One commonly used technique to determine the effective Z of the cargo is dual-energy imaging, i.e. imaging with different x-ray energy spectra. Another technique uses the fact that the transmitted x-ray spectrum itself also depends on the effective Z. Spectroscopy is difficult because the energy of individual x rays needs to be measured in a very high count-rate environment. Typical accelerators for security applications offer large but short bursts ofmore » x-rays, suitable for current-mode integrated imaging. In order to perform x-ray spectroscopy, a new accelerator design is desired that has the following features: 1) increased duty factor in order to spread out the arrival of x-rays at the detector array over time; 2) x-ray intensity modulation from one delivered pulse to the next by adjusting the accelerator electron beam instantaneous current so as to deliver adequate signal without saturating the spectroscopic detector; and 3) the capability to direct the (forward peaked) x-ray intensity towards high-attenuation areas in the cargo (“fan-beam-steering”). Current sources are capable of 0.1% duty factor, although usually they are operated at significantly lower duty factors (~0.04%), but duty factors in the range 0.4-1.0% are desired. The higher duty factor can be accomplished, e.g., by moving from 300 pulses per second (pps) to 1000 pps and/or increasing the pulse duration from a typical 4 μs to 10 μs. This paper describes initial R&D to examine cost effective modifications that could be performed on a typical accelerator for these purposes, as well as R&D for fan-beam steering.« less

  16. Results from the NSTX X-ray Crystal Spectrometer

    SciTech Connect (OSTI)

    M. Bitter; K. Hill; L. Roquemore; P. Beiersdorfer; D. Thorn; Ming Feng Gu

    2003-01-14

    A high-resolution X-ray crystal spectrometer has recently been installed at the National Spherical Torus Experiment to record the satellite spectra of helium-like argon, ArXVII, in the wavelength range from 3.94 to 4.00 {angstrom} for measurements of ion and electron temperatures, and measurements of the ionization equilibrium of argon, which is of interest for studies of ion transport. The instrument presently consists of a spherically bent quartz crystal and a conventional one-dimensional position-sensitive multi-wire proportional counter, but it will soon be upgraded to a new type of X-ray imaging crystal spectrometer by the installation of a large size (10 cm x 30 cm) two-dimensional position-sensitive detector that will allow us to obtain temporally and spatially resolved spectra from an 80 cm high cross-section of the plasma. In its present configuration, the spectrometer has been optimized for high throughput so that it is possible to record spectra with small statistical errors with a time resolution of 10 ms by adding only small, nonperturbing amounts of argon to the plasma. The spectrometer is most valuable for measurements of the ion temperature in the absence of a neutral beam in ohmically heated and radio-frequency heated discharges, when charge exchange recombination spectroscopy does not function. Electron temperature measurements from the satellite-to-resonance line ratios have been important for a quantitative comparison with (and verification of) the Thomson scattering data. The paper will describe the instrumental details of the present and future spectrometer configurations, and present recent experimental results.

  17. Density gradient free electron collisionally excited X-ray laser

    DOE Patents [OSTI]

    Campbell, Edward M.; Rosen, Mordecai D.

    1989-01-01

    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.

  18. Fabrication process for a gradient index x-ray lens

    DOE Patents [OSTI]

    Bionta, R.M.; Makowiecki, D.M.; Skulina, K.M.

    1995-01-17

    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.

  19. Soft x-ray reduction camera for submicron lithography

    DOE Patents [OSTI]

    Hawryluk, A.M.; Seppala, L.G.

    1991-03-26

    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.

  20. Density gradient free electron collisionally excited x-ray laser

    DOE Patents [OSTI]

    Campbell, E.M.; Rosen, M.D.

    1984-11-29

    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.

  1. Fabrication process for a gradient index x-ray lens

    DOE Patents [OSTI]

    Bionta, Richard M.; Makowiecki, Daniel M.; Skulina, Kenneth M.

    1995-01-01

    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.

  2. Soft x-ray reduction camera for submicron lithography

    DOE Patents [OSTI]

    Hawryluk, Andrew M.; Seppala, Lynn G.

    1991-01-01

    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.

  3. X-ray transmission movies of spontaneous dynamic events

    SciTech Connect (OSTI)

    Smilowitz, L.; Henson, B. F.; Holmes, M.; Novak, A.; Oschwald, D.; Dolgonos, P.; Qualls, B.

    2014-11-15

    We describe a new x-ray radiographic imaging system which allows for continuous x-ray transmission imaging of spontaneous dynamic events. We demonstrate this method on thermal explosions in three plastic bonded formulations of the energetic material octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine. We describe the x-ray imaging system and triggering developed to enable the continuous imaging of a thermal explosion.

  4. X-ray interferometry with spherically bent crystals (abstract)

    SciTech Connect (OSTI)

    Koch, Jeffrey A.

    2001-01-01

    Recent progress in manufacturing high-quality spherically bent crystals allows highly monochromatic x-ray beams to be produced, and allows efficient x-ray imaging with {mu}m-scale resolution. This article explores some of the constraints for x-ray interferometry utilizing spherically bent crystals and laser-produced plasma sources, and discusses several shearing interferometer concepts that might be experimentally investigated.

  5. Characterization of spatially resolved high resolution x-ray spectrometers

    Office of Scientific and Technical Information (OSTI)

    for high energy density physics and light source experiments (Journal Article) | SciTech Connect Characterization of spatially resolved high resolution x-ray spectrometers for high energy density physics and light source experiments Citation Details In-Document Search Title: Characterization of spatially resolved high resolution x-ray spectrometers for high energy density physics and light source experiments A high resolution 1D imaging x-ray spectrometer concept comprising a spherically

  6. 14.05.14 RH Synchrotron X-ray - JCAP

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

    High-Throughput Synchrotron X-Ray Experimentation for Combinatorial Phase Matching Gregoire, J. M. et al. High-throughput synchrotron X-ray diffraction for combinatorial phase mapping. Journal of Synchrotron Radiation 21, 1262-1268, DOI: 10.1107/s1600577514016488 (2014). Scientific Achievement Development of new synchrotron X-ray diffraction and fluorescence methods for rapid characterization of material libraries. Significance & impact First demonstration of prototype facility capable of

  7. Magnetism studies using resonant, coherent, x-ray scattering | Stanford

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

    Synchrotron Radiation Lightsource Magnetism studies using resonant, coherent, x-ray scattering Monday, September 10, 2012 - 10:00am SLAC, Bldg. 137, Room 226 Keoki Seu Seminar: With the advent of free electron lasers there has been interest in using coherent x-rays to probe condensed matter systems. Resonant scattering with x-rays allow elemental specificity with magnetic contrast, and coherent light leads to speckle in the scattered pattern due to interference from waves exiting the sample.

  8. ANL CT Reconstruction Algorithm for Utilizing Digital X-ray

    Energy Science and Technology Software Center (OSTI)

    2004-05-01

    Reconstructs X-ray computed tomographic images from large data sets known as 16-bit binary sinograms when using a massively parallelized computer architecture such as a Beowuif cluster by parallelizing the X-ray CT reconstruction routine. The algorithm uses the concept of generation of an image from carefully obtained multiple 1-D or 2-D X-ray projections. The individual projections are filtered using a digital Fast Fourier Transform. The literature refers to this as filtered back projection.

  9. Legacy of the X-Ray Laser Program

    SciTech Connect (OSTI)

    Nilsen, J.

    1993-08-06

    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.

  10. Ultra-short wavelength x-ray system

    DOE Patents [OSTI]

    Umstadter, Donald; He, Fei; Lau, Yue-Ying

    2008-01-22

    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.

  11. Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism

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

    Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism Print Wednesday, 29 August 2007 00:00 Using spectroscopic information for magnetometry and magnetic microscopy obviously requires detailed theoretical understanding of spectral shape and magnitude of dichroism signals. A research team at ALS Beamline 4.0.2 has now shown unambiguously that, contrary to common belief, spectral shape and magnitude of x-ray magnetic

  12. Femtosecond nanocrystallography using X-ray lasers for membrane...

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

    Authors: Fromme, P., and Spence, J. C. H. Title: Femtosecond nanocrystallography using X-ray lasers for membrane protein structure determination Source: Current Opinion in ...

  13. Using Light to Control How X Rays Interact with Matter

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

    the microscopic world, can have unwanted consequences for the materials they probe. Radiation damage due to x-ray absorption is, for instance, an unwanted consequence of using...

  14. Diagnostics Implemented on NIF - X-ray Diagnostics

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

    X-ray Diagnostics Diagnostic acronym Diangostic Port location Built and commisioned by Description of function Published references ARIANE Active Readout in a Neutron Environment (gated x-ray imager) 90-89 (but uses DIM) LLNL ARIANE is a gated x-ray detector measuring x-ray output at yields up to ~1E16 neutrons from TCC. ARIANE uses gated MCP technology adapted to operate in this neutron regime by moving the detector to a position just outside of the target chamber wall. ARIANE is typically used

  15. X-ray imaging of Nonlinear Resonant Gyrotropic Magnetic Vortex...

    Office of Scientific and Technical Information (OSTI)

    Vortex Core Motion in Circular Permalloy Disks Citation Details In-Document Search Title: X-ray imaging of Nonlinear Resonant Gyrotropic Magnetic Vortex Core Motion in ...

  16. Multiplet resonance lifetimes in resonant inelastic x-ray scattering...

    Office of Scientific and Technical Information (OSTI)

    shallow core levels Citation Details In-Document Search Title: Multiplet resonance lifetimes in resonant inelastic x-ray scattering involving shallow core levels Authors: ...

  17. Simulating Wavefront Correction via Deformable Mirrors at X-Ray...

    Office of Scientific and Technical Information (OSTI)

    Conference: Simulating Wavefront Correction via Deformable Mirrors at X-Ray Beamlines Citation Details In-Document Search Title: Simulating Wavefront Correction via Deformable ...

  18. Normal incidence x-ray mirror for chemical microanalysis

    DOE Patents [OSTI]

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

    1987-08-05

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

  19. X-ray compass for determining device orientation

    DOE Patents [OSTI]

    Da Silva, Luiz B.; Matthews, Dennis L.; Fitch, Joseph P.; Everett, Matthew J.; Colston, Billy W.; Stone, Gary F.

    1999-01-01

    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.

  20. 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.

    1999-06-15

    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.

  1. High intensity x-ray source using liquid gallium target

    DOE Patents [OSTI]

    Smither, Robert K. (Hinsdale, IL); Knapp, Gordon S. (Cupertino, CA); Westbrook, Edwin M. (Chicago, IL); Forster, George A. (Westmont, IL)

    1990-01-01

    A high intensity x-ray source that uses a flowing stream of liquid gallium as a target with the electron beam impinging directly on the liquid metal.

  2. X-Ray Diffraction Microscopy of Magnetic Structures (Journal...

    Office of Scientific and Technical Information (OSTI)

    Prev Next Title: X-Ray Diffraction Microscopy of Magnetic Structures Authors: Turner, Joshua J. ; Huang, Xiaojing ; Krupin, Oleg ; Seu, Keoki A. ; Parks, Daniel ; Kevan,...

  3. Intensity Pattern of Diffuse X-Ray Scattering From Thermally...

    Office of Scientific and Technical Information (OSTI)

    Intensity Pattern of Diffuse X-Ray Scattering From Thermally Populated Phonons in Fcc ... Sponsoring Org: DOE - BASIC ENERGY SCIENCESUNIVERSITY Country of Publication: United ...

  4. Biological Imaging by Soft X-Ray Diffraction Microscopy

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

    Biological Imaging by Soft X-Ray Diffraction Microscopy Biological Imaging by Soft X-Ray Diffraction Microscopy Print Wednesday, 30 November 2005 00:00 Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes

  5. Biological Imaging by Soft X-Ray Diffraction Microscopy

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

    methods (see previous highlight, "Demonstration of Coherent X-Ray Diffraction Imaging"). Experimental diffraction data used as input to the difference map algorithm....

  6. X-ray image reconstruction from a diffraction pattern alone

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Marchesini, Stefano

    2015-03-16

    X-ray diffraction pattern of a sample of 50 nm colloidal gold particles, recorded at a wavelength of 2.1 nm.

  7. X-Ray Microscopy Capabilities | Argonne National Laboratory

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

    The Hard X-Ray Nanoprobe (HXN) facility provides scanning fluorescence, scanning diffraction, and full-field transmission and tomographic imaging capabilities with a spatial...

  8. ALS X-Rays Shine a New Light on Catalysis

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

    ALS X-Rays Shine a New Light on Catalysis Print Electrocatalysts are responsible for expediting reactions in many promising renewable energy technologies. However, the extreme...

  9. Portable X-Ray Diffraction (XRD) | Open Energy Information

    Open Energy Info (EERE)

    X-ray powder diffraction, which has traditionally been used in geology, environmental science, material science, and engineering to rapidly identify unknown crystalline...

  10. X-Ray Diffraction (XRD) | Open Energy Information

    Open Energy Info (EERE)

    under investigation. X-ray powder diffraction is widely used in geology, environmental science, material science, and engineering to rapidly identify unknown crystalline substances...

  11. Advances in X-Ray Diagnostics of Diesel Fuel Sprays

    Broader source: Energy.gov [DOE]

    Recent advances in high-speed X-ray imaging has shown several distinct behaviors of commercial fuel injectors that cannot be seen with more conventional techniques.

  12. Integrated X-ray Reflectivity Measurements for Elliptically Curved...

    Office of Scientific and Technical Information (OSTI)

    The elliptically curved pentaerythritol (PET) crystals used in the Supersnout 2 X-ray spectrometer on the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory ...

  13. X-ray laser system, x-ray laser and method

    DOE Patents [OSTI]

    London, Richard A.; Rosen, Mordecai D.; Strauss, Moshe

    1992-01-01

    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.

  14. Laser photoelectron spectroscopy of ions

    SciTech Connect (OSTI)

    Ellison, G.B.

    1993-12-01

    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.

  15. New concepts for x-ray spectroscopy of tokamak plasmas

    SciTech Connect (OSTI)

    Fraenkel, B.S.; Bitter, M.

    1999-01-01

    The throughput of Bragg crystal spectrometers with two-dimensionally curved crystals has been computed and is found to be much larger than the throughput of conventional Johann spectrometers with cylindrically bent crystals. Special attention was given to spectrometers with spherically and toroidally bent crystals which provide, in addition to a high throughput, good spectral and spatial resolution. These spectrometers should meet the growing diagnostic requirements for present and future large tokamaks. {copyright} {ital 1999 American Institute of Physics.}

  16. Characterization of Gas Shales by X-ray Raman Spectroscopy |...

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

    SSRL Third Floor Conference Room 137-322 Drew Pomerantz, Schlumberger Unconventional hydrocarbon resources such as gas shale and oil-bearing shale have emerged recently as ...

  17. Characterization of Gas Shales by X-ray Raman Spectroscopy |...

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

    SSRL Conference Room 137-322 Drew Pomerantz, Schlumberger Unconventional hydrocarbon resources such as gas shale and oil-bearing shale have emerged recently as economically viable ...

  18. COLLOQUIUM: Development of High Resolution X-Ray Spectroscopy...

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

    at PPPL, adult visitors must show a government-issued photo I.D. - for example, a passport or a driver's license. Non-U.S. citizens must show a government-issued photo I.D.,...

  19. A paediatric X-ray exposure chart

    SciTech Connect (OSTI)

    Knight, Stephen P

    2014-09-15

    The aim of this review was to develop a radiographic optimisation strategy to make use of digital radiography (DR) and needle phosphor computerised radiography (CR) detectors, in order to lower radiation dose and improve image quality for paediatrics. This review was based on evidence-based practice, of which a component was a review of the relevant literature. The resulting exposure chart was developed with two distinct groups of exposure optimisation strategies – body exposures (for head, trunk, humerus, femur) and distal extremity exposures (elbow to finger, knee to toe). Exposure variables manipulated included kilovoltage peak (kVp), target detector exposure and milli-ampere-seconds (mAs), automatic exposure control (AEC), additional beam filtration, and use of antiscatter grid. Mean dose area product (DAP) reductions of up to 83% for anterior–posterior (AP)/posterior–anterior (PA) abdomen projections were recorded postoptimisation due to manipulation of multiple-exposure variables. For body exposures, the target EI and detector exposure, and thus the required mAs were typically 20% less postoptimisation. Image quality for some distal extremity exposures was improved by lowering kVp and increasing mAs around constant entrance skin dose. It is recommended that purchasing digital X-ray equipment with high detective quantum efficiency detectors, and then optimising the exposure chart for use with these detectors is of high importance for sites performing paediatric imaging. Multiple-exposure variables may need to be manipulated to achieve optimal outcomes.

  20. High resolution energy-sensitive digital X-ray

    DOE Patents [OSTI]

    Nygren, David R.

    1995-01-01

    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.

  1. High resolution energy-sensitive digital X-ray

    DOE Patents [OSTI]

    Nygren, D.R.

    1995-07-18

    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 detector such that each one of the 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. 5 figs.

  2. Workshops on Science Enabled by a Coherent, CW, Synchrotron X-ray Source, June 2011

    SciTech Connect (OSTI)

    Brock, Joel

    2012-01-03

    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.

  3. STRONG UV AND X-RAY VARIABILITY OF THE NARROW LINE SEYFERT 1 GALAXY WPVS 007-ON THE NATURE OF THE X-RAY LOW STATE

    SciTech Connect (OSTI)

    Grupe, Dirk; Barlow, Brad N.; Komossa, S.; Scharwaechter, Julia; Dietrich, Matthias; Leighly, Karen M.; Lucy, Adrian E-mail: julia.scharwaechter@obspm.fr

    2013-10-01

    We report on multi-wavelength observations of the X-ray transient Narrow Line Seyfert 1 (NLS1) galaxy WPVS 007. The galaxy was monitored with Swift between 2005 October and 2013 July, after it had previously undergone a dramatic drop in its X-ray flux. For the first time, we are able to repeatedly detect this NLS1 in X-rays again. This increased number of detections in the last couple of years may suggest that the strong absorber that has been found in this active galactic nucleus (AGN) is starting to become leaky and may eventually disappear. The X-ray spectra obtained for WPVS 007 are all consistent with a partial covering absorber model. A spectrum based on the data during the extreme low X-ray flux states shows that the absorption column density is of the order of 4 Multiplication-Sign 10{sup 23} cm{sup -2} with a covering fraction of 95%. WPVS 007 also displays one of the strongest UV variabilities seen in NLS1s. The UV continuum variability anti-correlates with the optical/UV slope {alpha}{sub UV}, which suggests that the variability may be primarily due to reddening. The UV variability timescales are consistent with moving dust ''clouds'' located beyond the dust sublimation radius of R{sub sub} Almost-Equal-To 20 lt-days. We present for the first time near-infrared JHK data of WPVS 007, which reveal a rich emission-line spectrum. Recent optical spectroscopy does not indicate significant variability in the broad permitted and Fe II emission lines, implying that the ionizing continuum seen by those gas clouds has not significantly changed over the last decades. All X-ray and UV observations are consistent with a scenario in which an evolving broad absorption line (BAL) flow obscures the continuum emission. As such, WPVS 007 is an important target for our understanding of BAL flows in low-mass AGNs.

  4. Probing the Early Stages of Solvation of cis-Pinate Dianions by Water, Acetonitrile, and Methanol: A Photoelectron Spectroscopy and Theoretical Study

    SciTech Connect (OSTI)

    Hou, Gao-Lei; Kong, Xiang-Tao; Valiev, Marat; Jiang, Ling; Wang, Xue B.

    2016-01-01

    Cis-pinic acid is one of the most important oxidation products of α-pinene – a key monoterpene compound in biogenic emission processes affecting the atmosphere. Molecular level understanding of interactions involved in the cluster formations around cis-pinic acid is an important and necessary prerequisite toward ascertaining its role in the aerosol formation processes. In this work, we studied the structures and energetics of the solvated clusters of cis-pinate (cis-PA²⁻), the doubly deprotonated dicarboxylate of cis-pinic acid, with H₂O, CH₃OH, and CH₃CN by negative ion photoelectron spectroscopy and ab initio theoretical calculations. We found that cis-PA²⁻ prefers being solvated alternately on the two -CO₂⁻ groups with increase of solvent coverage, a well-known solvation pattern that has been observed in microhydrated linear dicarboxylate dianion (DCn²⁻) clusters. Experiments and calculations further reveal an intriguing feature for the existence of the asymmetric type isomers for cis-PA2–(H2O)2 and cis-PA²⁻(CH₃OH)₂, in which both solvent molecules interact with only one of the -CO²⁻ groups – a phenomena that has not been observed in DCn²⁻ water clusters and exhibits the subtle effect of the rigid four-membered carbon ring brought in on the cis-PA²⁻ solvation. The dominant interactions between cis-PA²⁻ and solvent molecules are forming bidentate O–···H–O H-bonds for H₂O, O–···H–O and O–···H–C H-bonds for CH₃OH, and tridentate O–···H–C H-bonds for CH₃CN. The formation of inter-solvent H-bonds between H₂O and CH₃CN is found to be favorable in mixed solvent clusters, distinctly different from that between H₂O and CH₃OH. These findings have important implications for understanding the mechanism of cluster growth and nucleation of atmospheric organic aerosols and the nature of structure-function relationship of proteins containing carboxylate groups under various solvent environments.

  5. The Ground State of (CS)4 Is Different from that of (CO)4: An Experimental Test of a Computational Prediction by Negative Ion Photoelectron Spectroscopy

    SciTech Connect (OSTI)

    Zhang, Jian; Hrovat, David; Sun, Zhenrong; Bao, Xiaoguang; Borden, Weston; Wang, Xue B.

    2013-08-22

    Cyclobutane-1,2,3,4-tetrathione, (CS)4, has recently been calculated to have a singlet ground state, 1A1g, in which the highest b2g  MO is doubly occupied and the lowest a2u  MO is empty. Thus, (CS)4 is predicted to have a different ground state than its lighter congener, (CO)4, which has a triplet ground state, 3B1u, in which these two MOs are each singly occupied. Here we report the results of a negative ion photoelectron spectroscopy (NIPES) study of the radical anion (CS)4●-, designed to test the prediction that (CS)4 has a singlet ground state. The NIPE spectrum reveals that (CS)4 does, indeed, have a singlet ground state with electron affinity (EA) = 3.75 eV. The lowest triplet state is found to lie 0.31 eV higher in energy than the ground state, and the open-shell singlet is 0.14 eV higher in energy than the triplet state. Calculations at the (U)CCSD(T)/aug-cc-pVTZ//(U)B3LYP/6-311+G(2df) level support the spectral assignments, giving EA = 3.71 eV, EST = 0.44 eV. These calculated values are, respectively, 0.04 eV (0.9 kcal/mol) smaller, and 0.13 eV (3.0 kcal/mol) larger than the corresponding experimental values. In addition, RASPT2 calculations with various active spaces converge on a 1B1u-3B1u energy gap of 0.137 eV, in excellent agreement with the 0.14 eV energy difference obtained from the NIPE spectrum. Finally, calculations of the Franck-Condon factors for transitions from the ground state of (CS)4●- to the ground (1A1g) and two excited states (3B1u, 1B1u) of (CS)4 account for all of the major spectral peaks, and nicely reproduce vibrational structure observed in each electronic transition. The close correspondence between the calculated and the observed features in the NIPE spectrum of (CS)4●- provides unequivocal proof that (CS)4, unlike (CO)4, has a singlet ground state.

  6. Apparatus for generating x-ray holograms

    DOE Patents [OSTI]

    Rhodes, C.K.; Boyer, K.; Solem, J.C.; Haddad, W.S.

    1990-09-11

    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.

  7. Apparatus for generating x-ray holograms

    DOE Patents [OSTI]

    Rhodes, Charles K.; Boyer, Keith; Solem, Johndale C.; Haddad, Waleed S.

    1990-01-01

    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.

  8. 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.

    2012-01-20

    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.

  9. An X-ray flare from 47 Cas

    SciTech Connect (OSTI)

    Pandey, Jeewan C.; Karmakar, Subhajeet

    2015-02-01

    Using XMM-Newton observations, we investigate properties of a flare from the very active but poorly known stellar system 47 Cas. The luminosity at the peak of the flare is found to be 3.54 10{sup 30} erg s{sup ?1}, which is ?2 times higher than that at a quiescent state. The quiescent state corona of 47 Cas can be represented by two temperature plasma: 3.7 and 11.0 MK. The time-resolved X-ray spectroscopy of the flare show the variable nature of the temperature, the emission measure, and the abundance. The maximum temperature during the flare is derived as 72.8 MK. We infer the length of a flaring loop to be 3.3 10{sup 10} cm using a hydrodynamic loop model. Using the RGS spectra, the density during the flare is estimated as 4.0 10{sup 10} cm{sup ?3}. The loop scaling laws are also applied when deriving physical parameters of the flaring plasma.

  10. Effects of chemo-mechanical polishing on CdZnTe X-ray and gamma-ray detectors

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

    Egarievwe, Stephen E.; Hossain, Anwar; Okwechime, Ifechukwude O.; Gul, Rubi; James, Ralph B.

    2015-06-23

    Here, mechanically polishing cadmium zinc telluride (CdZnTe) wafers for x-ray and gamma-ray detectors often is inadequate in removing surface defects caused by cutting them from the ingots. Fabrication-induced defects, such as surface roughness, dangling bonds, and nonstoichiometric surfaces, often are reduced through polishing and etching the surface. In our earlier studies of mechanical polishing with alumina powder, etching with hydrogen bromide in hydrogen peroxide solution, and chemomechanical polishing with bromine–methanol–ethylene glycol solution, we found that the chemomechanical polishing process produced the least surface leakage current. In this research, we focused on using two chemicals to chemomechanically polish CdZnTe wafers aftermore » mechanical polishing, viz. bromine–methanol–ethylene glycol (BME) solution, and hydrogen bromide (HBr) in a hydrogen peroxide and ethylene–glycol solution. We used x-ray photoelectron spectroscopy (XPS), current–voltage (I–V) measurements, and Am-241 spectral response measurements to characterize and compare the effects of each solution. The results show that the HBr-based solution produced lower leakage current than the BME solution. Results from using the same chemomechanical polishing solution on two samples confirmed that the surface treatment affects the measured bulk current (a combination of bulk and surface currents). XPS results indicate that the tellurium oxide to tellurium peak ratios for the mechanical polishing process were reduced significantly by chemomechanical polishing using the BME solution (78.9% for Te 3d5/2O2 and 76.7% for Te 3d3/2O2) compared with the HBr-based solution (27.6% for Te 3d5/2O2 and 35.8% for Te 3d3/2O2). Spectral response measurements showed that the 59.5-keV peak of Am-241 remained under the same channel number for all three CdZnTe samples. While the BME-based solution gave a better performance of 7.15% full-width at half-maximum (FWHM) compared with 7.59% FWHM for the HBr-based solution, the latter showed a smaller variation in performance of 0.39% FWHM over 7 days compared with 0.69% for the BME-based solution.« less

  11. NEW X-RAY DETECTIONS OF WNL STARS

    SciTech Connect (OSTI)

    Skinner, Stephen L.; Zhekov, Svetozar A.; Guedel, Manuel; Schmutz, Werner; Sokal, Kimberly R.

    2012-05-15

    Previous studies have demonstrated that putatively single nitrogen-type Wolf-Rayet stars (WN stars) without known companions are X-ray sources. However, almost all WN star X-ray detections so far have been of earlier WN2-WN6 spectral subtypes. Later WN7-WN9 subtypes (also known as WNL stars) have proved more difficult to detect, an important exception being WR 79a (WN9ha). We present here new X-ray detections of the WNL stars WR 16 (WN8h) and WR 78 (WN7h). These new results, when combined with previous detections, demonstrate that X-ray emission is present in WN stars across the full range of spectral types, including later WNL stars. The two WN8 stars observed to date (WR 16 and WR 40) show unusually low X-ray luminosities (L{sub x} ) compared to other WN stars, and it is noteworthy that they also have the lowest terminal wind speeds (v{sub {infinity}}). Existing X-ray detections of about a dozen WN stars reveal a trend of increasing L{sub x} with wind luminosity L{sub wind} = (1/2)M-dot v{sup 2}{sub {infinity}}, suggesting that wind kinetic energy may play a key role in establishing X-ray luminosity levels in WN stars.

  12. Laser-Produced Coherent X-Ray Sources

    SciTech Connect (OSTI)

    Donald Umstadter

    2007-01-31

    We study the generation of x-rays from the interaction of relativistic electrons with ultra-intense laser pulse either directly or via laser generated ion channels. The laser pulse acts as the accelerator and wiggler leading to an all-optical synchrotron-like x-ray source. The mm sized accelerator and micron-sized wiggler leads to a compact source of high brightness, ultrafast x-rays with applications in relativistic nonlinear optics, ultrafast chemistry, biology, inner-shell electronic processes and phase transitions.

  13. X-ray backscatter imaging of nuclear materials

    DOE Patents [OSTI]

    Chapman, Jeffrey Allen; Gunning, John E; Hollenbach, Daniel F; Ott, Larry J; Shedlock, Daniel

    2014-09-30

    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.

  14. 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

    2013-07-01

    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.

  15. 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, Pecs7624 (Hungary)] [Institute of Physics, University of Pecs, Pecs7624 (Hungary); Hebling, J. [Institute of Physics, University of Pecs, Pecs7624 (Hungary) [Institute of Physics, University of Pecs, Pecs7624 (Hungary); Szentagothai Research Centre, University of Pecs, Pecs-7624 (Hungary); Mishra, S. K. [Institute for Plasma Research, Gandhinagar (India)] [Institute for Plasma Research, Gandhinagar (India)

    2014-03-15

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

  16. Resonant x-ray magnetic scattering in holmium

    SciTech Connect (OSTI)

    Gibbs, D.

    1991-01-01

    We review the results of resonant x-ray magnetic scattering experiments on the rare earth metal holmium. When the incident incident x-ray energy is tuned near the L{sub III} absorption edge, large resonant enhancements of the magnetic scattering and resonant integer harmonics are observed. These results are analyzed within the theory of x-ray resonance exchange scattering assuming electric dipole (2p {yields} 5d) and quadrupole (2p {yields} 4f) transitions among atomic orbitals. 30 refs., 5 figs.

  17. FIRST IMAGES FROM THE FOCUSING OPTICS X-RAY SOLAR IMAGER

    SciTech Connect (OSTI)

    Krucker, Sm; Glesener, Lindsay; Turin, Paul; McBride, Stephen; Glaser, David; Fermin, Jose; Lin, Robert; Christe, Steven; Ishikawa, Shin-nosuke; Ramsey, Brian; Gubarev, Mikhail; Kilaru, Kiranmayee; Takahashi, Tadayuki; Watanabe, Shin; Saito, Shinya; Tanaka, Takaaki; White, Stephen

    2014-10-01

    The Focusing Optics X-ray Solar Imager (FOXSI) sounding rocket payload flew for the first time on 2012 November2, producing the first focused images of the Sun above 5keV. To enable hard X-ray (HXR) imaging spectroscopy via direct focusing, FOXSI makes use of grazing-incidence replicated optics combined with fine-pitch solid-state detectors. On its first flight, FOXSI observed several targets that included active regions, the quiet Sun, and a GOES-class B2.7 microflare. This Letter provides an introduction to the FOXSI instrument and presents its first solar image. These data demonstrate the superiority in sensitivity and dynamic range that is achievable with a direct HXR imager with respect to previous, indirect imaging methods, and illustrate the technological readiness for a spaceborne mission to observe HXRs from solar flares via direct focusing optics.

  18. X-ray absorption spectroscopic studies of mononuclear non-heme iron enzymes

    SciTech Connect (OSTI)

    Westre, T.E.

    1996-01-01

    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.

  19. A versatile medium-resolution x-ray emission spectrometer for diamond anvil cell applications

    SciTech Connect (OSTI)

    Mortensen, D. R.; Seidler, G. T.; Bradley, J. A.; Lipp, M. J.; Evans, W. J.; Chow, P.; Xiao, Y.-M.; Boman, G.; Bowden, M. E.

    2013-08-15

    We present design and performance details for a polycapillary-coupled x-ray spectrometer that provides very high collection efficiency at a moderate energy resolution suitable for many studies of nonresonant x-ray emission spectroscopy, especially for samples of heavy elements under high pressures. Using a single Bragg analyzer operating close to backscattering geometry so as to minimize the effect of the weak divergence of the quasicollimated exit beam from the polycapillary optic, this instrument can maintain a typical energy resolution of 5 eV over photon energies from 5 keV to 10 keV. We find dramatically improved count rates as compared to a traditional higher-resolution instrument based on a single spherically bent crystal analyzer.

  20. MICROANALYSIS OF NY/NJ HARBOR SEDIMENTS USING SYNCHROTRON X-RAY BEAMS.

    SciTech Connect (OSTI)

    JONES,K.W.FENG,H.LANZIROTTI,A.MARINKOVIC,N.ET AL.

    2003-12-31

    Sediments found in the New York/New Jersey Harbor are widely contaminated with organic and inorganic compounds of anthropogenic origin. As a result, the environmental health of the Harbor has deteriorated and the efficient operation of the Port compromised by difficulties in disposing of sediments resulting from maintenance and improvements of navigational channels. Knowledge of the properties of the sediments on a micro-scale is useful in understanding the transport of contaminants through the environment, for developing effective methods for sediment decontamination, and for subsequent beneficial use of the cleaned sediments. We have investigated several properties of these sediments using synchrotron radiation techniques. These include computed microtomography using absorption and fluorescence contrast mechanisms, x-ray microscopy, microbeam x-ray fluorescence, and Fourier Transform Infrared Spectroscopy (FTIR) for measurements of microstructure, distribution of metals on individual sediment particles, and chemical forms of the contaminants on a micrometer scale. Typical results obtained with these techniques are presented.

  1. Interfacial Magnetism in Complex Oxide Heterostructures Probed by Neutrons and X-rays

    SciTech Connect (OSTI)

    Liu, Yaohua; Ke, Xianglin

    2015-09-02

    Magnetic complex-oxide heterostructures are of keen interest because a wealth of phenomena at the interface of dissimilar materials can give rise to fundamentally new physics and potentially valuable functionalities. Altered magnetization, novel magnetic coupling and emergent interfacial magnetism at the epitaxial layered-oxide interfaces have all been intensively investigated, which shapes our understanding on how to utilize those materials, particularly for spintronics. Neutron and x-ray based techniques have played a decisive role in characterizing interfacial magnetic structures and clarifying the underlying physics in this rapidly developing field. Here we review some recent experimental results, with an emphasis on those studied via polarized neutron reflectometery and polarized x-ray absorption spectroscopy. We conclude with some perspectives.

  2. Biological Imaging by Soft X-Ray Diffraction Microscopy

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

    and angles of x rays scattered from the sample rather than transmitted through it). Shapiro et al. have now chimed in with the first lensless imaging of a sample as complex as a...

  3. X-ray imaging reveals secrets in battery materials | Argonne...

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

    X-ray imaging reveals secrets in battery materials June 22, 2015 Tweet EmailPrint Imaging and data analysis techniques offer new approach to probing material properties In a new...

  4. Biological Imaging by Soft X-Ray Diffraction Microscopy

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

    Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with...

  5. ALS X-Rays Shine a New Light on Catalysis

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

    vice versa. At the ALS, researchers were able to directly observe redox processes in thin-film iron and cobalt perovskite oxide electrocatalysts using surface-sensitive, x-ray...

  6. Using Light to Control How X Rays Interact with Matter

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

    Using Light to Control How X Rays Interact with Matter Print Schemes that use one light pulse to manipulate interactions of another with matter are well developed in the...

  7. In situ Nanotomography and Operando Transmission X-ray Microscopy...

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

    and Operando Transmission X-ray Microscopy of Micron-sized Ge Particles in Battery Anodes Friday, August 29, 2014 Ge fig1 Figure 1. Schematic of the irreversible...

  8. Development Of a Spatially Resolving X-ray Crystal Spectrometer...

    Office of Scientific and Technical Information (OSTI)

    Ion-temperature (Ti) And Rotation-velocity (v) Profiles in ITER Citation Details ... Ion-temperature (Ti) And Rotation-velocity (v) Profiles in ITER Imaging x-ray crystal ...

  9. Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism

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

    of the XMLD signal across the Ni L2,3 edges was determined by rotating the orientation of x-ray polarization E and external magnetic field H relative to the crystalline axes. ...

  10. Detecting rare, abnormally large grains by x-ray diffraction

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

    ... Detecting rare, abnormally large grains by x-ray diffraction large-grains The theme of the Nanomechanics and Nanometallurgy of Boundaries project at Sandia National Labs is to ...

  11. X-Ray Diffraction Microscopy of Magnetic Structures

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

    Lensless Imaging of Magnetic Nanostructures Work performed on ALS Beamline 12.0.2.2 Citation: J.J. Turner et al., "X-Ray Diffraction Microscopy of Magnetic Structures," Phys....

  12. High order reflectivity of graphite (HOPG) crystals for x ray...

    Office of Scientific and Technical Information (OSTI)

    High order reflectivity of graphite (HOPG) crystals for x ray energies up to 22 keV Citation Details In-Document Search Title: High order reflectivity of graphite (HOPG) crystals ...

  13. High performance x-ray anti-scatter grid

    DOE Patents [OSTI]

    Logan, Clinton M.

    1995-01-01

    An x-ray anti-scatter grid for x-ray imaging, particularly for screening mammography, and method for fabricating same, x-rays incident along a direct path pass through a grid composed of a plurality of parallel or crossed openings, microchannels, grooves, or slots etched in a substrate, such as silicon, having the walls of the microchannels or slots coated with a high opacity material, such as gold, while x-rays incident at angels with respect to the slots of the grid, arising from scatter, are blocked. The thickness of the substrate is dependent on the specific application of the grid, whereby a substrate of the grid for mammography would be thinner than one for chest radiology. Instead of coating the walls of the slots, such could be filed with an appropriate liquid, such as mercury.

  14. X-ray mask and method for making

    DOE Patents [OSTI]

    Morales, Alfredo M.

    2004-10-26

    The present invention describes a method for fabricating an x-ray mask tool which is a contact lithographic mask which can provide an x-ray exposure dose which is adjustable from point-to-point. The tool is useful in the preparation of LIGA plating molds made from PMMA, or similar materials. In particular the tool is useful for providing an ability to apply a graded, or "stepped" x-ray exposure dose across a photosensitive substrate. By controlling the x-ray radiation dose from point-to-point, it is possible to control the development process for removing exposed portions of the substrate; adjusting it such that each of these portions develops at a more or less uniformly rate regardless of feature size or feature density distribution.

  15. Systems and methods for detecting x-rays

    DOE Patents [OSTI]

    Bross, Alan D.; Mellott, Kerry L.; Pla-Dalmau, Anna

    2006-05-02

    Systems and methods for detecting x-rays are disclosed herein. One or more x-ray-sensitive scintillators can be configured from a plurality of heavy element nano-sized particles and a plastic material, such as polystyrene. As will be explained in greater detail herein, the heavy element nano-sized particles (e.g., PbWO4) can be compounded into the plastic material with at least one dopant that permits the plastic material to scintillate. X-rays interact with the heavy element nano-sized particles to produce electrons that can deposit energy in the x-ray sensitive scintillator, which in turn can produce light.

  16. High performance x-ray anti-scatter grid

    DOE Patents [OSTI]

    Logan, C.M.

    1995-05-23

    Disclosed are an x-ray anti-scatter grid for x-ray imaging, particularly for screening mammography, and method for fabricating same, x-rays incident along a direct path pass through a grid composed of a plurality of parallel or crossed openings, microchannels, grooves, or slots etched in a substrate, such as silicon, having the walls of the microchannels or slots coated with a high opacity material, such as gold, while x-rays incident at angels with respect to the slots of the grid, arising from scatter, are blocked. The thickness of the substrate is dependent on the specific application of the grid, whereby a substrate of the grid for mammography would be thinner than one for chest radiology. Instead of coating the walls of the slots, such could be filed with an appropriate liquid, such as mercury. 4 Figs.

  17. X-ray photonic microsystems for the manipulation of synchrotron...

    Office of Scientific and Technical Information (OSTI)

    ... Techniques (Wiley, 2002). 14. Als-Nielsen, J. & McMorrow, D. Elements of Modern X-ray Physics 2nd Ed. 207-237 (Wiley, 2011). 15. Kubby, J. A. (Ed) Adaptive Optics for ...

  18. Simulating Wavefront Correction via Deformable Mirrors at X-Ray...

    Office of Scientific and Technical Information (OSTI)

    DOE Contract Number: W-7405-ENG-48 Resource Type: Conference Resource Relation: Conference: Presented at: X-ray Adaptive Optics, San Diego, CA, United States, Aug 14 - Aug 14, 2012 ...

  19. Vitreous carbon mask substrate for X-ray lithography

    DOE Patents [OSTI]

    Aigeldinger, Georg; Skala, Dawn M.; Griffiths, Stewart K.; Talin, Albert Alec; Losey, Matthew W.; Yang, Chu-Yeu Peter

    2009-10-27

    The present invention is directed to the use of vitreous carbon as a substrate material for providing masks for X-ray lithography. The new substrate also enables a small thickness of the mask absorber used to pattern the resist, and this enables improved mask accuracy. An alternative embodiment comprised the use of vitreous carbon as a LIGA substrate wherein the VC wafer blank is etched in a reactive ion plasma after which an X-ray resist is bonded. This surface treatment provides a surface enabling good adhesion of the X-ray photoresist and subsequent nucleation and adhesion of the electrodeposited metal for LIGA mold-making while the VC substrate practically eliminates secondary radiation effects that lead to delamination of the X-ray resist form the substrate, the loss of isolated resist features, and the formation of a resist layer adjacent to the substrate that is insoluble in the developer.

  20. X-ray Diffraction from Membrane Protein Nanocrystals

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

    X-ray Diffraction from Membrane Protein Nanocrystals Authors: Hunter, M.S., DePonte, D.P., Shapiro, D.A., Kirian, R.A., Wang, X., Starodub, D., Marchesini, S., Weierstall, U.,...

  1. X-ray Microscopy and Imaging (XSD-XMI)

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

    and (c) technical R&D in collaborations with other groups on nano-focusing x-ray optics, image contrast mechanisms, phase-retrieval methodology, detectors and data...

  2. Soft x-ray capabilities for investigating the strongly correlated...

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

    Soft x-ray capabilities for investigating the strongly correlated electron materials Friday, September 14, 2012 - 1:00pm SLAC, Bldg. 137, Room 226 Jun-Sik Lee Seminar One of the...

  3. Lensless Imaging of Magnetic Nanostructures by X-ray Spectro...

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

    J. Lning, W. F. Schlotter and J. Sthr (SSRL) The unprecedented properties of X-ray free electron lasers (X-FELs) under development world wide will open the door for entirely...

  4. Generation of Coherent X-Ray Radiation through Modulation Compression...

    Office of Scientific and Technical Information (OSTI)

    attoseconds pulse, 1 nm coherent X-ray radiation using a 60 A electron beam out of the linac and 200 nm laser seed. Both the final wavelength and the radiation pulse length in the ...

  5. Effect of a synchrotron X-ray microtomography imaging experiment...

    Office of Scientific and Technical Information (OSTI)

    Effect of a synchrotron X-ray microtomography imaging experiment on the amino acid content of a CM chondrite Citation Details In-Document Search Title: Effect of a synchrotron ...

  6. HIgh Rate X-ray Fluorescence Detector

    SciTech Connect (OSTI)

    Grudberg, Peter Matthew

    2013-04-30

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

  7. Dose optimization in cardiac x-ray imaging

    SciTech Connect (OSTI)

    Gislason-Lee, Amber J.; McMillan, Catherine; Cowen, Arnold R.; Davies, Andrew G.

    2013-09-15

    Purpose: The aim of this research was to optimize x-ray image quality to dose ratios in the cardiac catheterization laboratory. This study examined independently the effects of peak x-ray tube voltage (kVp), copper (Cu), and gadolinium (Gd) x-ray beam filtration on the image quality to radiation dose balance for adult patient sizes.Methods: Image sequences of polymethyl methacrylate (PMMA) phantoms representing two adult patient sizes were captured using a modern flat panel detector based x-ray imaging system. Tin and copper test details were used to simulate iodine-based contrast medium and stents/guide wires respectively, which are used in clinical procedures. Noise measurement for a flat field image and test detail contrast were used to calculate the contrast to noise ratio (CNR). Entrance surface dose (ESD) and effective dose measurements were obtained to calculate the figure of merit (FOM), CNR{sup 2}/dose. This FOM determined the dose efficiency of x-ray spectra investigated. Images were captured with 0.0, 0.1, 0.25, 0.4, and 0.9 mm Cu filtration and with a range of gadolinium oxysulphide (Gd{sub 2}O{sub 2}S) filtration.Results: Optimum x-ray spectra were the same for the tin and copper test details. Lower peak tube voltages were generally favored. For the 20 cm phantom, using 2 Lanex Fast Back Gd{sub 2}O{sub 2}S screens as x-ray filtration at 65 kVp provided the highest FOM considering ESD and effective dose. Considering ESD, this FOM was only marginally larger than that from using 0.4 mm Cu at 65 kVp. For the 30 cm phantom, using 0.25 mm copper filtration at 80 kVp was most optimal; considering effective dose the FOM was highest with no filtration at 65 kVp.Conclusions: These settings, adjusted for x-ray tube loading limits and clinically acceptable image quality, should provide a useful option for optimizing patient dose to image quality in cardiac x-ray imaging. The same optimal x-ray beam spectra were found for both the tin and copper details, suggesting that iodine contrast based imaging and visualization of interventional devices could potentially be optimized for dose using similar x-ray beam spectra.

  8. New Directions in X-Ray Light Sources

    ScienceCinema (OSTI)

    Falcone, Roger

    2010-01-08

    July 15, 2008 Berkeley Lab lecture: Molecular movies of chemical reactions and material phase transformations need a strobe of x-rays, the penetrating light that reveals how atoms and molecules assemble in chemical and biological systems and complex materials. Roger Falcone, Director of the Advanced Light Source,will discuss a new generation of x ray sources that will enable a new science of atomic dynamics on ultrafast timescales.

  9. ALS X-Rays Shine a New Light on Catalysis

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

    ALS X-Rays Shine a New Light on Catalysis Print Electrocatalysts are responsible for expediting reactions in many promising renewable energy technologies. However, the extreme sensitivity of their surface redox states to temperatures, to gas pressures, and to electrochemical reaction conditions renders them difficult to investigate by conventional surface-science techniques. Recently a team of Stanford and Berkeley Lab researchers used x-rays at the ALS in a novel way to observe the behavior of

  10. ALS X-Rays Shine a New Light on Catalysis

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

    ALS X-Rays Shine a New Light on Catalysis Print Electrocatalysts are responsible for expediting reactions in many promising renewable energy technologies. However, the extreme sensitivity of their surface redox states to temperatures, to gas pressures, and to electrochemical reaction conditions renders them difficult to investigate by conventional surface-science techniques. Recently a team of Stanford and Berkeley Lab researchers used x-rays at the ALS in a novel way to observe the behavior of

  11. Probing Spatial, Electronic Structures with X-ray Scattering, Spectroscopic

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

    Techniques | Stanford Synchrotron Radiation Lightsource Probing Spatial, Electronic Structures with X-ray Scattering, Spectroscopic Techniques Wednesday, September 5, 2012 - 10:45am SLAC, Bldg. 137, Room 226 Gang Chen Seminar: Structures at atomic scales are traditionally determined through X-ray crystallography that amplifies scattering intensities by introducing spatial periodicity. For amorphous materials and many macromolecules, such as viruses, proteins and biofilms, it is hard to

  12. Self-cleaning rotating anode X-ray source

    DOE Patents [OSTI]

    Paulikas, Arvydas P.

    1989-01-01

    A self-cleaning rotating anode x-ray source comprising an evacuable housing, a rotatable cylindrical anode within the housing, a source of electrons within the housing which electrons are caused to impinge upon the anode to produce x-rays, and means for ionizing residual particles within the housing and accelerating such ions so as to impinge upon the anode to sputter impurities from the surface thereof.

  13. ALS X-Rays Shine a New Light on Catalysis

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

    ALS X-Rays Shine a New Light on Catalysis Print Electrocatalysts are responsible for expediting reactions in many promising renewable energy technologies. However, the extreme sensitivity of their surface redox states to temperatures, to gas pressures, and to electrochemical reaction conditions renders them difficult to investigate by conventional surface-science techniques. Recently a team of Stanford and Berkeley Lab researchers used x-rays at the ALS in a novel way to observe the behavior of

  14. ALS X-Rays Shine a New Light on Catalysis

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

    ALS X-Rays Shine a New Light on Catalysis Print Electrocatalysts are responsible for expediting reactions in many promising renewable energy technologies. However, the extreme sensitivity of their surface redox states to temperatures, to gas pressures, and to electrochemical reaction conditions renders them difficult to investigate by conventional surface-science techniques. Recently a team of Stanford and Berkeley Lab researchers used x-rays at the ALS in a novel way to observe the behavior of

  15. ALS X-Rays Shine a New Light on Catalysis

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

    ALS X-Rays Shine a New Light on Catalysis Print Electrocatalysts are responsible for expediting reactions in many promising renewable energy technologies. However, the extreme sensitivity of their surface redox states to temperatures, to gas pressures, and to electrochemical reaction conditions renders them difficult to investigate by conventional surface-science techniques. Recently a team of Stanford and Berkeley Lab researchers used x-rays at the ALS in a novel way to observe the behavior of

  16. ALS X-Rays Shine a New Light on Catalysis

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

    ALS X-Rays Shine a New Light on Catalysis Print Electrocatalysts are responsible for expediting reactions in many promising renewable energy technologies. However, the extreme sensitivity of their surface redox states to temperatures, to gas pressures, and to electrochemical reaction conditions renders them difficult to investigate by conventional surface-science techniques. Recently a team of Stanford and Berkeley Lab researchers used x-rays at the ALS in a novel way to observe the behavior of

  17. ALS X-Rays Shine a New Light on Catalysis

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

    ALS X-Rays Shine a New Light on Catalysis ALS X-Rays Shine a New Light on Catalysis Print Thursday, 21 May 2015 11:16 Electrocatalysts are responsible for expediting reactions in many promising renewable energy technologies. However, the extreme sensitivity of their surface redox states to temperatures, to gas pressures, and to electrochemical reaction conditions renders them difficult to investigate by conventional surface-science techniques. Recently a team of Stanford and Berkeley Lab

  18. Self-cleaning rotating anode x-ray source

    DOE Patents [OSTI]

    Paulikas, A.P.

    1987-06-02

    A self-cleaning rotating anode x-ray source comprising and evacuable housing, a rotatable cylindrical anode within the housing, a source of electrons within the housing which electrons are caused to impinge upon the anode to produce x-rays, and means for ionizing residual particles within the housing and accelerating such ions so as to impinge upon the anode to sputter impurities from the surface thereof. 2 figs.

  19. X-ray tube with magnetic electron steering

    DOE Patents [OSTI]

    Reed, Kim W. (Albuquerque, NM); Turman, Bobby N. (Albuquerque, NM); Kaye, Ronald J. (Albuquerque, NM); Schneider, Larry X. (Albuquerque, NM)

    2000-01-01

    An X-ray tube uses a magnetic field to steer electrons. The magnetic field urges electrons toward the anode, increasing the proportion of electrons emitted from the cathode that reach desired portions of the anode and consequently contribute to X-ray production. The magnetic field also urges electrons reflected from the anode back to the anode, further increasing the efficiency of the tube.

  20. Polarized X-Rays Reveal Molecular Alignment in Printed Electronics

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

    Polarized X-Rays Reveal Molecular Alignment in Printed Electronics Polarized X-Rays Reveal Molecular Alignment in Printed Electronics Print Wednesday, 31 October 2012 00:00 The printing of electronic devices using giant roll-to-roll presses or inkjet-style printers has recently been made possible by the development of solution-processable organic materials with optoelectronic properties. Organic light-emitting diodes (OLEDs) are already being produced commercially, and sensors, organic thin-film