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1

The new ambient-pressure X-ray photoelectron spectroscopy instrument at MAX-lab  

Science Journals Connector (OSTI)

The new instrument for ambient-pressure X-ray photoelectron spectroscopy at the Swedish synchrotron radiation facility MAX IV Laboratory is presented. The instrument is based on the use of a retractable and exchangeable high-pressure cell, which implies that ultrahigh-vacuum conditions are retained in the analysis chamber and that dual ambient pressure and ultrahigh-vacuum use is possible.

Schnadt, J.

2012-08-07T23:59:59.000Z

2

E-Print Network 3.0 - ambient-pressure x-ray photoelectron Sample...  

NLE Websites -- All DOE Office Websites (Extended Search)

Spectroscopie Electronique, Summary: of an X-ray source from measurements of the kinetic energy and intensity of the photoelectrons emitted... applications in electron probe...

3

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

SciTech Connect

The lack of fundamental understanding of the oxygen reduction and oxygen evolution in nonaqueous electrolytes significantly hinders the development of rechargeable lithium-air batteries. Here we employ a solid-state Li4+xTi5O12/LiPON/LixV2O5 cell and examine in situ the chemistry of Li-O2 reaction products on LixV2O5 as a function of applied voltage under ultra high vacuum (UHV) and near ambient-pressure of oxygen using X-ray photoelectron spectroscopy (APXPS). Oxygen reduction and evolution reactions take place on the surface of the mixed electronic and Li+ ionic conductor, LixV2O5, which eliminate parasitic reactions between oxygen reduction/evolution reaction intermediates and aprotic electrolytes used in Li-O2 batteries reported to date. Under UHV, reversible lithium intercalation and de-intercalation from LixV2O5 was noted, where the changes in the vanadium valence state revealed from XPS in this study were comparable to that reported previously from Li/LixV2O5 thin film batteries. In presence of oxygen near ambient pressure, the LixV2O5 surface was covered gradually by the reaction product of oxygen reduction, namely lithium peroxide (Li2O2) (approximately 1-2 unit cells) upon discharge. Interestingly, the LixV2O5 surface became re-exposed upon charging, and the oxidation of Li2O2 began at much lower overpotentials (~240 mV) than the charge overpotentials of Li-O2 cells (~1000 mV) with aprotic electrolytes, which can be attributed to subnanometer-thick Li2O2 with surfaces free of contaminants such as carbonate species. Our study provides first evidence of reversible lithium peroxide formation and decomposition in situ on an oxide surface using a solid-state cell, and new insights into the reaction mechanism of Li-O2 chemistry.

Lu, Yi-chun [Massachusetts Institute of Technology (MIT); Crumlin, Ethan [Massachusetts Institute of Technology (MIT); Veith, Gabriel M [ORNL; Harding, Jonathon [Massachusetts Institute of Technology (MIT); Dudney, Nancy J [ORNL; Liu, Zhi [Lawrence Berkeley National Laboratory (LBNL); Shao-Horn, Yang [Massachusetts Institute of Technology (MIT)

2012-01-01T23:59:59.000Z

4

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

SciTech Connect

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

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

2006-02-01T23:59:59.000Z

5

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

SciTech Connect

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.

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

2010-03-31T23:59:59.000Z

6

Correlation between Charge State of Insulating NaCl Surfaces and Ionic Mobility Induced by Water Adsorption: A Combined Ambient Pressure X-ray Photoelectron Spectroscopy and Scanning Force Microscopy Study  

SciTech Connect

In situ ambient pressure X-ray photoelectron spectroscopy (APPES) and scanning force microscopy were used to characterize the surface discharge induced by water layers grown on (001) surfaces of sodium chloride single crystals. The APPES studies show that both kinetic energy (KE) and full width at half-maximum (FWHM) of the Na 2s and Cl 2p core level peaks, monitored as a function of relative humidity (RH), mimic surface conductivity curves measured using scanning force microscopy. The KE position and FWHM of the core level peaks therefore are directly related to the solvation and diffusion of ions at the NaCl(100) surface upon adsorption of water.

Verdaguer, Albert; Jose Segura, Juan; Fraxedas, Jordi; Bluhm, Hendrik; Salmeron, Miquel

2008-09-03T23:59:59.000Z

7

Molecular Studies of Surfaces under Reaction Conditions; Sum Frequency Generation Vibrational Spectroscopy, Scanning Tunneling Microscopy and Ambient Pressure X-Ray Photoelectron Spectroscopy  

SciTech Connect

Instruments developed in our laboratory permit the atomic and molecular level study of NPs under reaction conditions (SFG, ambient pressure XPS and high pressure STM). These studies indicate continuous restructuring of the metal substrate and the adsorbate molecules, changes of oxidation states with NP size and surface composition variations of bimetallic NPs with changes of reactant molecules.

Somorjai, G.A.

2009-11-11T23:59:59.000Z

8

Electron yield soft X-ray photoabsorption spectroscopy under normal ambient-pressure conditions  

Science Journals Connector (OSTI)

Soft X-ray photoabsorption spectroscopy under normal ambient-pressure conditions using electron yield detection was demonstrated. This technique provided unambiguous photoabsorption data for hydrated transition-metal compounds and identified the different chemical states of cobalt ions.

Tamenori, Y.

2013-03-16T23:59:59.000Z

9

Ambient pressure photoelectron spectroscopy: a new tool for surface science and nanotechnology  

SciTech Connect

Progress in science often follows or parallels the development of new techniques. The optical microscope helped convert medicine and biology from a speculative activity in old times to today's sophisticated scientific disciplines. The telescope changed the study and interpretation of heavens from mythology to science. X-ray diffraction enabled the flourishing of solid state physics and materials science. The technique object of this review, Ambient Pressure Photoelectron Spectroscopy or APPES for short, has also the potential of producing dramatic changes in the study of liquid and solid surfaces, particularly in areas such as atmospheric, environment and catalysis sciences. APPES adds an important missing element to the host of techniques that give fundamental information, i.e., spectroscopy and microscopy, about surfaces in the presence of gases and vapors, as encountered in industrial catalysis and atmospheric environments. APPES brings electron spectroscopy into the realm of techniques that can be used in practical environments. Decades of surface science in ultra high vacuum (UHV) has shown the power of electron spectroscopy in its various manifestations. Their unique property is the extremely short elastic mean free path of electrons as they travel through condensed matter, of the order of a few atomic distances in the energy range from a few eV to a few thousand eV. As a consequence of this the information obtained by analyzing electrons emitted or scattered from a surface refers to the top first few atomic layers, which is what surface science is all about. Low energy electron diffraction (LEED), Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), Ultraviolet photoelectron spectroscopy (UPS), and other such techniques have been used for decades and provided some of the most fundamental knowledge about surface crystallography, composition and electronic structure available today. Unfortunately the high interaction cross section of electrons with matter also prevents them from traveling long distances unscattered in gas environments. Above the millibar pressure range this distance is reduced to less that a millimeter, effectively preventing its use in the most relevant environments, usually between millibars and atmospheric pressures. There is therefore a large gap of several orders of magnitude where information about surfaces is scarce because these powerful electron spectroscopies cannot operate. One characteristic of surfaces in ambient pressure environments is that they are covered by dense layers of molecules, even when their binding energy is weak. Water for example is known to form layers several molecules thick at room temperature in humid environments. Metals readily form oxide films several layers thick in oxygen atmospheres. Dense layers of adsorbed molecules can also be produced in ultra high vacuum, often by the simple and expedient method of cooling the sample to cryogenic temperatures. A large amount of data has been obtained in the past in UHV by surface scientists using this method. While this has provided valuable information it begs the question of whether the structures formed in this manner represent equilibrium structures or metastable ones, kinetically trapped due to high activation energies that cannot be overcome at low temperature. From a thermodynamic point of view is interesting to consider the entropic contribution to the Gibbs free energy, which we can call 'the pressure factor', equal to kT.logP. This factor amounts to a sizeable 0.3 eV difference at room temperature between UHV (<10{sup -8} Pascal) and atmospheric pressures. Such change if free energy can definitely result in changes in surface structure and stability. Entire areas of the phase diagram are out of reach due to the pressure gap. Even when cooling is not necessary, many surface treatments and most chemical reactions necessitate the presence of gases at pressures ranging from millibar to bars. What is the structure and chemical nature of the species formed on the surface in equilibrium with suc

Salmeron, Miquel; Salmeron, Miquel; Schlogl, Robert

2008-03-12T23:59:59.000Z

10

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...

11

X-Ray Photoelectron Spectroscopy XPS Mark Engelhard  

E-Print Network (OSTI)

X-Ray Photoelectron Spectroscopy XPS Mark Engelhard 1 #12;EMSL XPS Instrumentation 2 Physical Electronics Quantera XPS High Energy Resolution Focused X-ray Beam Capability Catalysis reaction and processing chamber with inert atmosphere glove box connected to a PHI Quantera Scanning X-ray Microprobe

12

Development of x-ray photoelectron microscope with an x-ray laser source  

Science Journals Connector (OSTI)

We have constructed an x-ray photoelectron microscopic system with an x-ray laser as an x-ray source. The lasing line is the Li-like Al 3d-4f transition at 15.47 nm where the recombining Al plasma is used as the x-ray laser medium. The beam from the x-ray laser cavity was then focused by using a Schwarzschild mirror coated with Mo/Si multilayers. The x-ray beam size with a diameter less than 0.5 ?m and the estimated photon number of about 2×10 6 ? photons/shot into the spot were achieved.

Tadayuki Ohchi; Naohiro Yamaguchi; Chiemi Fujikawa; Tamio Hara; Katsumi Watanabe; Ibuki Tanaka; Masami Taguchi

2000-01-01T23:59:59.000Z

13

X-ray Photoelectron Spectroscopy (XPS) | EMSL  

NLE Websites -- All DOE Office Websites (Extended Search)

photoelectron spectroscopy (UPS), ion scattering spectroscopy (ISS), a clusterAr+ ion gun, and a five-axis automated stage with variable temperature sample environment at the...

14

Beyond hard x-ray photoelectron spectroscopy: Simultaneous combination with x-ray diffraction  

SciTech Connect

Hard x-ray photoelectron spectroscopy (HAXPES) is a powerful and novel emerging technique for the nondestructive determination of electronic properties and chemical composition of bulk, buried interfaces and surfaces. It benefits from the exceptionally large escape depth of high kinetic energy photoelectrons, increasing the information depth up to several tens of nanometers. Complementing HAXPES with an atomic structure sensitive technique (such as x-ray diffraction) opens a new research field with major applications for materials science. At SpLine, the Spanish CRG beamline at the European Synchrotron Radiation Facility, we have developed a novel experimental set-up that combines HAXPES and x-ray diffraction (x-ray reflectivity, surface x-ray diffraction, grazing incidence x-ray diffraction, and reciprocal space maps). Both techniques can be operated simultaneously on the same sample and using the same excitation source. The set-up includes a robust 2S + 3D diffractometer hosting a ultrahigh vacuum chamber equipped with a unique photoelectron spectrometer (few eV < electron kinetic energy < 15 keV), x-ray tube (Mg/Ti), 15 keV electron gun, and auxiliary standard surface facilities (molecular beam epitaxy evaporator, ion gun, low energy electron diffraction, sample heating/cooling system, leak valves, load-lock sample transfer, etc.). This end-station offers the unique possibility of performing simultaneous HAXPES + x-ray diffraction studies. In the present work, we describe the experimental set-up together with two experimental examples that emphasize its outstanding capabilities: (i) nondestructive characterization of the Si/Ge and HfO{sub 2}/SiO{sub 2} interfaces on Ge-based CMOS devices, and (ii) strain study on La{sub 0.7}Ca{sub 0.3}MnO{sub 3} ultrathin films grown on SrTiO{sub 3}(001) substrate.

Rubio-Zuazo, Juan; Castro, German R. [SpLine, Spanish CRG beamline at the European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble (France) and ICMM-CSIC Cantoblanco, E-28049 Madrid (Spain)

2013-05-15T23:59:59.000Z

15

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

E-Print Network (OSTI)

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

Lu, Yi-chun

16

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

E-Print Network (OSTI)

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

17

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

SciTech Connect

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

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

2007-10-29T23:59:59.000Z

18

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

SciTech Connect

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

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

2010-02-01T23:59:59.000Z

19

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

E-Print Network (OSTI)

NPs on TiO 2 support in UHV. The peaks on the higher energymonolayer) of Au on TiO 2 under UHV and under 1 Torr of Oany effect related to the UHV condition alone, we have

Jiang, Peng

2010-01-01T23:59:59.000Z

20

X-ray Photoelectron Spectroscopy Studies of Oxidized and Reduced CeO?(111) Surfaces  

SciTech Connect

We have studied the electronic structure of oxidized and reduced CeO? (111) surfaces using X-ray photoelectron spectroscopy (XPS). The 50 nm thick Co?(111) film was grown on a YSZ(111) substrate using oxygen plasma assisted molecular beam epitaxy (OPA-MBE). This film has been characterized using in-situ RHEED (reflection high energy electron diffraction) and ex-situ XRD (X-ray diffraction), HRTEM (high resolution transmission electron microscopy) and RBS (Rutherford backscattering spectroscopy). The lattice mismatch between CeO?(111) and YSZ(111) is less than 5% and yields a flat surface that is comprised of an equivalent number of Ce?? and O?? ions. Oxidation with O? at 773 K under UHV conditions was sufficient to fully oxidize the CeO?(111). Surface reduction was carried out by annealing in UHV at 973 K.

Engelhard, Mark H.; Azad, Samina; Peden, Charles HF; Thevuthasan, Suntharampillai

2004-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

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

SciTech Connect

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.

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

2013-09-09T23:59:59.000Z

22

Oxidation of stepped Pt(111) studied by x-ray photoelectron spectroscopy and density functional theory  

SciTech Connect

In this comparative density functional theory and x-ray photoelectron spectroscopy study on the interaction of oxygen with stepped Pt(111) surfaces, we show that both the initial adsorption and oxidation occur at the steps rather than terraces. An equivalent behavior was observed for the oxide formation at higher chemical potentials, where, after the formation of a one-dimensional PtO{sub 2}-type oxide at the steps, similar oxide chains form on the (111) terraces, indicating the initial stages of bulk oxide formation.

Bandlow, Jochen; Kaghazchi, Payam; Jacob, Timo [Institut fuer Elektrochemie, Universitaet Ulm, Albert-Einstein-Allee 47, D-89069 Ulm (Germany); Papp, C.; Traenkenschuh, B.; Streber, R.; Lorenz, M. P. A.; Fuhrmann, T.; Steinrueck, H.-P. [Lehrstuhl fuer Physikalische Chemie II, Universitaet Erlangen-Nuernberg, Egerlandstr. 3, D-91058 Erlangen (Germany); Denecke, R. [Wilhelm-Ostwald-Institut fuer Physikalische und Theoretische Chemie, Universitaet Leipzig, Linnestr. 2, D-04103 Leipzig (Germany)

2011-05-01T23:59:59.000Z

23

X-ray Photoelectron Spectroscopy of GaP{1-x}N(x) Photocorroded as a Result of Hydrogen Production through Water Electrolysis  

E-Print Network (OSTI)

X-ray Photoelectron Spectroscopy of GaP{1-x}N(x) Photocorroded as a Result of Hydrogen Production through Water Electrolysis

Mayer, Marie A

2006-01-01T23:59:59.000Z

24

X-ray photoelectron spectroscopy analysis of organic materials etched by charged water droplet impact  

SciTech Connect

Electrospray droplet impact (EDI) has been developed for matrix-free secondary ion mass spectrometry for surface analysis. When a target is etched by EDI, the physical etching on the target is suppressed to minimal, i.e., the occurrence of shallow surface etching. A novel approach to shallow surface etching of polystyrene (PS) by EDI was investigated. The charged water droplets were irradiated to a bulk and a spin coated PS. After irradiation, these samples were analyzed by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy. It was found that XPS spectra for PS were independent on the irradiation time by EDI. This indicates that EDI is a unique technique for the surface etching of the organic materials without leaving any damage on the etched surface.

Sakai, Yuji; Iijima, Yoshitoki; Takaishi, Riou; Asakawa, Daiki; Hiraoka, Kenzo [Clean Energy Research Center, University of Yamanashi, Takeda 4-3-11, Kofu 400-8511, Japan and Japan Science and Technology Agency Innovation Satellite, Shizuoka, 3-5-1 Johoku, Nakaku, Hamamatsu 432-8561 (Japan); Electron Optics Sales Division, JEOL Ltd., 2-8-3 Akebono, Tachikawa, Tokyo 190-0012 (Japan); Clean Energy Research Center, University of Yamanashi, Takeda 4-3-11, Kofu 400-8511 (Japan)

2009-07-15T23:59:59.000Z

25

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

SciTech Connect

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

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

2014-02-21T23:59:59.000Z

26

Conductivity and X-ray photoelectron studies on lithium acetate doped chitosan films  

Science Journals Connector (OSTI)

Chitosan, ethylene carbonate (EC) and lithium acetate (LiOAc) were mixed in the desired proportions and dissolved in 100 ml of 1% acetic acid solutions. The solutions were then poured into various petri dishes and left to form films at room temperature. Complexation was confirmed by X-ray photoelectron spectroscopy (XPS). The lithium signal can be deconvoluted into three gaussian component peaks. One of the peaks at ?55 eV is attributed to Li–N interaction. The nitrogen signal can be deconvoluted into two gaussian component peaks. The peak at ?403.1 eV is attributed to N–Li interaction. The electrical conductivity of all samples was calculated using the bulk resistance value obtained from the complex impedance plot in the frequency range between 1 kHz and 1 MHz. The highest electrical conductivity obtained for the film containing LiOAc is 7.6×10?6 S cm?1 at room temperature. The plot of conductivity, ? versus dopant content indicates that ? increases with increasing dopant content up to a dopant amount of 0.8 g LiOAc. The plot of ln ?T versus 103/T for each lithium acetate sample between 298 and 363 K shows beys Arrhenius behavior indicating that the conductivity occurs by way of some thermally assisted mechanism. The chitosan based samples may have potential use in replacing the liquid components of electrochromic devices.

M.Z.A. Yahya; A.K. Arof

2004-01-01T23:59:59.000Z

27

Electronic structure and x-ray photoelectron spectroscopy of the ?, ?, and ? phases of Np  

Science Journals Connector (OSTI)

The electronic structure, density of states, and x-ray photoelectron spectroscopy (XPS) intensities of the ?, ?, and ? phases of Np have been theoretically determined from self-consistent, fully relativistic, linear muffin-tin-orbital band-structure calculations. The calculated XPS intensities show a large f peak that narrows (due to the larger volumes per atom) and moves closer to the Fermi energy as one progresses through the ?, ?, and ? phases. Experimental XPS intensities of the ? and ? phases are also presented and compared to the theoretical calculations. Experimentally, the ? and ? intensities are found to be almost identical, and do not show any evidence for the theoretically predicted f-band narrowing. In addition, there is a large additional experimental intensity at higher binding energy that is not present in the calculations. This extra intensity may be evidence for quasilocalized behavior of the 5f electronic states that is induced by the XPS process. For example, the low-energy tail may be related to either multiplet or satellite structure due to final-state localized atomiclike correlation effects. © 1996 The American Physical Society.

R. C. Albers; A. M. Boring; J. M. Wills; L. E. Cox; O. E. Eriksson; N. E. Christensen

1996-11-15T23:59:59.000Z

28

Observation and simulation of hard x ray photoelectron diffraction to determine polarity of polycrystalline zinc oxide films with rotation domains  

SciTech Connect

X ray photoelectron diffraction (XPD) patterns of polar zinc oxide (ZnO) surfaces were investigated experimentally using hard x rays and monochromatized Cr K{alpha} radiation and theoretically using a cluster model approach and a dynamical Bloch wave approach. We focused on photoelectrons emitted from the Zn 2p{sub 3/2} and O 1s orbitals in the analysis. The obtained XPD patterns for the (0001) and (0001) surfaces of a ZnO single crystal were distinct for a given emitter and polarity. Polarity determination of c-axis-textured polycrystalline ZnO thin films was also achieved with the concept of XPD, even though the in-plane orientation of the columnar ZnO grains was random.

Williams, Jesse R.; Adachi, Yutaka; Ohashi, Naoki [International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); NIMS Saint-Gobain Research Center of Excellence for Advanced Materials, NIMS, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Pis, Igor [Synchrotron X-ray Station at SPring-8, NIMS, SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University, V Holesovickach 2, Prague 8 18000 (Czech Republic); Kobata, Masaaki [Synchrotron X-ray Station at SPring-8, NIMS, SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Winkelmann, Aimo [Max-Planck-Institut fuer Mikrostrukturphysik, Weinberg 2, D-06120 Halle (Saale) (Germany); Matsushita, Tomohiro [Japan Synchrotron Radiation Research Institute (JASRI), SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Kobayashi, Keisuke [Synchrotron X-ray Station at SPring-8, NIMS, SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046 (Japan)

2012-02-01T23:59:59.000Z

29

Probing buried layers by photoelectron spectromicroscopy with hard x-ray excitation  

SciTech Connect

We report about a proof-of-principle experiment which explores the perspectives of performing hard x-ray photoemission spectromicroscopy with high lateral resolution. Our results obtained with an energy-filtered photoemission microscope at the PETRA III storage ring facility using hard x-ray excitation up to 6.5 keV photon energy demonstrate that it is possible to obtain selected-area x-ray photoemission spectra from regions less than 500 nm in diameter.

Wiemann, C.; Patt, M.; Cramm, S. [Peter Gruenberg Institute (PGI-6) and JARA-FIT, Research Centre Juelich, D-52425 Juelich (Germany); Escher, M.; Merkel, M. [FOCUS GmbH, D-65510 Huenstetten (Germany); Gloskovskii, A. [Institut fuer Anorganische Chemie und Analytische Chemie, Johannes Gutenberg-Universitaet Mainz, D-55128 Mainz (Germany); Thiess, S.; Drube, W. [DESY Photon Science, Deutsches Elektronen-Synchrotron, D-22603 Hamburg (Germany); Schneider, C. M. [Peter Gruenberg Institute (PGI-6) and JARA-FIT, Research Centre Juelich, D-52425 Juelich (Germany); Fakultaet f. Physik and Center for Nanointegration Duisburg-Essen (CENIDE), Universitaet Duisburg-Essen, D-47048 Duisburg (Germany)

2012-05-28T23:59:59.000Z

30

Structure, Mobility, and Composition of Transition Metal Catalyst Surfaces: High-Pressure Scanning Tunneling Microscopy and Ambient-Pressure X-ray Photoelectron Spectroscopy Studies  

E-Print Network (OSTI)

bimetallic nanoparticle catalysts is studied in Chapter 8.and Pt-based bimetallic nanoparticle catalysts, in order toseek the influence of catalyst surface structure on

Zhu, Zhongwei

2014-01-01T23:59:59.000Z

31

Structure, Mobility, and Composition of Transition Metal Catalyst Surfaces: High-Pressure Scanning Tunneling Microscopy and Ambient-Pressure X-ray Photoelectron Spectroscopy Studies  

E-Print Network (OSTI)

in this thesis, including UHV and AES, are also brieflysurfaces need to be prepared in UHV, since samples will bethan the terraces in UHV, implying the partial reversibility

Zhu, Zhongwei

2014-01-01T23:59:59.000Z

32

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

SciTech Connect

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

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

2014-01-01T23:59:59.000Z

33

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

SciTech Connect

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

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

2013-11-15T23:59:59.000Z

34

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

SciTech Connect

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.

Zhu, L. Q.; Barrett, N.; Jegou, P. [Groupe Photoemission, CEA/IRAMIS/SPCSI, F-91191 Gif-sur-Yvette (France); Martin, F.; Leroux, C.; Martinez, E.; Grampeix, H.; Renault, O.; Chabli, A. [CEA-LETI, MINATEC, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France)

2009-01-15T23:59:59.000Z

35

Uptake of Toxic Metal Ions from Water by Naked and Monolayer Protected Silver Nanoparticles: An X-ray Photoelectron Spectroscopic Investigation  

Science Journals Connector (OSTI)

Uptake of Toxic Metal Ions from Water by Naked and Monolayer Protected Silver Nanoparticles: An X-ray Photoelectron Spectroscopic Investigation ... Several other remedial measures including nano zerovalent iron (nzvi) has been proposed. ... Although several studies have investigated gold from the perspective of heavy metal remediation, investigations to such depth have not happened with silver. ...

M. S. Bootharaju; T. Pradeep

2010-04-15T23:59:59.000Z

36

In situ x-ray photoelectron spectroscopy studies of gas/solidinterfaces at near-ambient conditions  

SciTech Connect

X-ray photoelectron spectroscopy (XPS) is a quantitative, chemically specific technique with a probing depth of a few angstroms to a few nanometers. It is therefore ideally suited to investigate the chemical nature of the surfaces of catalysts. Because of the scattering of electrons by gas molecules, XPS is generally performed under vacuum conditions. However, for thermodynamic and/or kinetic reasons, the catalyst's chemical state observed under vacuum reaction conditions is not necessarily the same as that of a catalyst under realistic operating pressures. Therefore, investigations of catalysts should ideally be performed under reaction conditions, i.e., in the presence of a gas or gas mixtures. Using differentially pumped chambers separated by small apertures, XPS can operate at pressures of up to 1 Torr, and with a recently developed differentially pumped lens system, the pressure limit has been raised to about 10 Torr. Here, we describe the technical aspects of high-pressure XPS and discuss recent applications of this technique to oxidation and heterogeneous catalytic reactions on metal surfaces.

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

2007-12-03T23:59:59.000Z

37

UV-Raman spectroscopy, X-ray photoelectron spectroscopy, and temperature programmed desorption studies of model and bulk heterogeneous catalysts  

SciTech Connect

X-ray photoelectron spectroscopy (XPS) and Temperature Programmed Desorption (TPD) have been used to investigate the surface structure of model heterogeneous catalysts in ultra-high vacuum (UHV). UV-Raman spectroscopy has been used to probe the structure of bulk model catalysts in ambient and reaction conditions. The structural information obtained through UV-Raman spectroscopy has been correlated with both the UHV surface analysis and reaction results. The present day propylene and ethylene polymerization catalysts (Ziegler-Natta catalysts) are prepared by deposition of TiCl{sub 4} and a Al(Et){sub 3} co-catalyst on a microporous Mg-ethoxide support that is prepared from MgCl{sub 2} and ethanol. A model thin film catalyst is prepared by depositing metallic Mg on a Au foil in a UHV chamber in a background of TiCl{sub 4} in the gas phase. XPS results indicate that the Mg is completely oxidized to MgCl{sub 2} by TiCl{sub 4} resulting in a thin film of MgCl{sub 2}/TiCl{sub x}, where x = 2, 3, and 4. To prepare an active catalyst, the thin film of MgCl{sub 2}/TiCl{sub x} on Au foil is enclosed in a high pressure cell contained within the UHV chamber and exposed to {approx}1 Torr of Al(Et){sub 3}.

Tewell, Craig R.

2002-08-19T23:59:59.000Z

38

Satellites in x-ray photoelectron spectroscopy of insulators. II. Multielectron excitations in LiF, NaF, and KF  

Science Journals Connector (OSTI)

The satellites appearing in the core regions of the x-ray photoelectron spectra of alkali fluorides have been investigated in order to obtain information about the distribution of interband transitions. The photoemission results are compared with some recent theoretical band-structure calculations. The differences in the relative intensities observed in the different core regions are ascribed to the presence of excitons in the spectra.

Marisa Scrocco

1985-07-15T23:59:59.000Z

39

Impact of Mg concentration on energy-band-depth profile of Mg-doped InN epilayers analyzed by hard X-ray photoelectron spectroscopy  

SciTech Connect

The electronic structures of Mg-doped InN (Mg-InN) epilayers with the Mg concentration, [Mg], ranging from 1 × 10{sup 19} to 5 × 10{sup 19} cm{sup ?3} were systematically investigated by soft and hard X-ray photoelectron spectroscopies. The angle-resolved results on the core-level and valence band photoelectron spectra as a function of [Mg] revealed that the energy band of Mg-InN showed downward bending due to the n{sup +} surface electron accumulation and p type layers formed in the bulk. With an increase in [Mg], the energy-band changed from monotonic to two-step n{sup +}p homojunction structures. The oxygen concentration rapidly increased at the middle-bulk region (?4.5 to ?7.5 nm) from the surface, which was one of the reasons of the transformation of two-step energy band.

Imura, M.; Tsuda, S.; Nagata, T.; Takeda, H.; Liao, M. Y.; Koide, Y. [National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)] [National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Yang, A. L.; Yamashita, Y.; Yoshikawa, H.; Kobayashi, K. [NIMS/SPring-8, NIMS, 1-1-1 Koto, Sayo-cho, Sayo, Hyogo 679-5148 (Japan)] [NIMS/SPring-8, NIMS, 1-1-1 Koto, Sayo-cho, Sayo, Hyogo 679-5148 (Japan); Yamaguchi, T. [Faculty of Engineering, Kogakuin University, 2665-1 Nakano-machi, Hachiouji, Tokyo 192-0015 (Japan) [Faculty of Engineering, Kogakuin University, 2665-1 Nakano-machi, Hachiouji, Tokyo 192-0015 (Japan); Faculty of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu 525-8577 (Japan); Kaneko, M.; Uematsu, N.; Wang, K.; Araki, T. [Faculty of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu 525-8577 (Japan)] [Faculty of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu 525-8577 (Japan); Nanishi, Y. [Faculty of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu 525-8577 (Japan) [Faculty of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu 525-8577 (Japan); Faculty of Materials Science and Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)

2013-10-14T23:59:59.000Z

40

Ambient pressure fuel cell system  

DOE Patents (OSTI)

An ambient pressure fuel cell system is provided with a fuel cell stack formed from a plurality of fuel cells having membrane/electrode assemblies (MEAs) that are hydrated with liquid water and bipolar plates with anode and cathode sides for distributing hydrogen fuel gas and water to a first side of each one of the MEAs and air with reactant oxygen gas to a second side of each one of the MEAs. A pump supplies liquid water to the fuel cells. A recirculating system may be used to return unused hydrogen fuel gas to the stack. A near-ambient pressure blower blows air through the fuel cell stack in excess of reaction stoichiometric amounts to react with the hydrogen fuel gas.

Wilson, Mahlon S. (Los Alamos, NM)

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Ultrahigh vacuum sample mount for x-ray photoelectron spectroscopy up to very high temperature (150-1400 K)  

SciTech Connect

Spectroscopic studies are rarely performed at very high temperature, especially when combined with light from a synchrotron source. Demanding conditions of maintaining ultrahigh vacuum (UHV) during heating, together with the typically brief access to beam time at multiuser synchrotron end stations, may contribute to some of the reasons for the difficulty of such experiments. Consequently, a large number of materials with interesting properties and industrial applications at high temperature remain unexplored. The authors describe here a simple portable sample mount assembly that can be easily utilized at a beamline, with potential utility for a variety of spectroscopic measurements requiring elevated temperatures and an UHV environment. In the specific application described here, the authors use a resistive cartridge heater interfaced with a standard manipulator previously designed for cooling by liquid nitrogen with an UHV chamber and a cylindrical mirror analyzer for x-ray photoemission spectroscopy (XPS) [also known as electron spectroscopy for chemical analysis (ESCA)] at the Synchrotron Radiation Center in Stoughton, WI. The heater cartridge required only modest power to reach target temperatures using an open-loop temperature control. Finally, the authors describe the measurements of XPS (ESCA) and total-electron yield x-ray absorption spectroscopy on nanopowders and on single crystals grown by them. They emphasize the simplicity of the setup, which they believe would be of interest to groups performing measurements at large facilities, where access and time are both limited.

Williamsen, Mark S.; Ray, Shishir K.; Zou Ying; Dudek, John A.; Sen, Somaditya; Bissen, Mark; Kretsch, Laura; Palkar, Vaijayanti R.; Onellion, Marshall F.; Guptasarma, Prasenjit [Department of Physics, University of Wisconsin-Milwaukee, 1900 E. Kenwood Blvd., Milwaukee, Wisconsin 53211 (United States); Synchrotron Radiation Center, 3731 Schneider Dr., Stoughton, Wisconsin 53589 (United States); Department of Electrical Engineering, Indian Institute of Technology Bombay, Mumbai 400076 (India); Department of Physics, University of Wisconsin--Madison, 1150 University Ave., Madison, Wisconsin 53706 (United States); Department of Physics, University of Wisconsin-Milwaukee, 1900 E. Kenwood Blvd., Milwaukee, Wisconsin 53211 (United States)

2011-05-15T23:59:59.000Z

42

Hard x-ray photoelectron spectroscopy study on band alignment at poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/ZnO interface  

SciTech Connect

We used hard x-ray photoelectron spectroscopy to investigate the interfacial electronic states of a poly(styrenesulfonate) doped poly(3,4-ethylenedioxythiophene) (PEDOT:PSS) contact on a ZnO single crystal. An understanding of the interfacial band structure is useful for putting the organic contact to practical use. We observed upward band bending of the ZnO layer a few nanometers from the interface. The detected ZnO bulk region exhibited a flat band structure, meaning that the PEDOT:PSS does not greatly deplete the ZnO layer. The band bending caused the charge injection barrier formation with the result that the contact exhibited the Schottky property.

Nagata, T.; Hayakawa, R.; Chikyow, T. [International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan); Oh, S.; Wakayama, Y. [International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan); Department of Chemistry and Biochemistry, Faculty of Engineering, Kyushu University, 1-1 Namiki, Tsukuba 305-0044 (Japan); Yamashita, Y. [International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan); NIMS Beamline Station at SPring-8, National Institute for Materials Science, 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Yoshikawa, H.; Kobayashi, K. [NIMS Beamline Station at SPring-8, National Institute for Materials Science, 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

2012-10-22T23:59:59.000Z

43

Initial stages of ITO/Si interface formation: In situ x-ray photoelectron spectroscopy measurements upon magnetron sputtering and atomistic modelling using density functional theory  

SciTech Connect

Initial stages of indium tin oxide (ITO) growth on a polished Si substrate upon magnetron sputtering were studied experimentally using in-situ x-ray photoelectron spectroscopy measurements. The presence of pure indium and tin, as well as Si bonded to oxygen at the ITO/Si interface were observed. The experimental observations were compared with several atomistic models of ITO/Si interfaces. A periodic model of the ITO/Si interface was constructed, giving detailed information about the local environment at the interface. Molecular dynamics based on density functional theory was performed, showing how metal-oxygen bonds are broken on behalf of silicon-oxygen bonds. These theoretical results support and provide an explanation for the present as well as previous ex-situ and in-situ experimental observations pointing to the creation of metallic In and Sn along with the growth of SiO{sub x} at the ITO/Si interface.

Løvvik, O. M.; Diplas, S.; Ulyashin, A. [SINTEF Materials and Chemistry, Forskningsveien 1, NO-0314 Oslo (Norway); Romanyuk, A. [University of Basel, Kingelbergstr. 82, CH-4056 Basel (Switzerland)

2014-02-28T23:59:59.000Z

44

Investigation of the near-surface structures of polar InN films by chemical-state-discriminated hard X-ray photoelectron diffraction  

SciTech Connect

Near-surface structures of polar InN films were investigated by laboratory-based hard X-ray photoelectron diffraction (HXPD) with chemical-state-discrimination. HXPD patterns from In 3d{sub 5/2} and N 1s core levels of the In-polar and N-polar InN films were different from each other and compared with the simulation results using a multiple-scattering cluster model. It was found that the near-surface structure of the In-polar InN film was close to the ideal wurtzite structure. On the other hand, on the N-polar InN film, defects-rich surface was formed. In addition, the existence of the In-polar domains was observed in the HXPD patterns.

Yang, A. L.; Yamashita, Y.; Kobata, M.; Yoshikawa, H.; Sakata, O.; Kobayashi, K. [Synchrotron X-ray Station at SPring-8, National Institute for Materials Science, Sayo-cho, Hyogo 679-5148 (Japan)] [Synchrotron X-ray Station at SPring-8, National Institute for Materials Science, Sayo-cho, Hyogo 679-5148 (Japan); Matsushita, T. [Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo-cho, Hyogo 679-5198 (Japan)] [Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo-cho, Hyogo 679-5198 (Japan); Pis, I. [Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University, V Holesovickach 2, 18000 Prague 8 (Czech Republic)] [Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University, V Holesovickach 2, 18000 Prague 8 (Czech Republic); Imura, M. [Wide Bandgap Materials Group, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan)] [Wide Bandgap Materials Group, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan); Yamaguchi, T. [Department of Photonics, Ritsumeikan University, Kusatsu, Shiga 525-8577 (Japan)] [Department of Photonics, Ritsumeikan University, Kusatsu, Shiga 525-8577 (Japan); Nanishi, Y. [WCU Hybrid Materials Program, Department of Materials Science and Engineering, Seoul National University, Seoul 151-744, South Korea and Research Organization of Science and Engineering, Ritsumeikan University, 1-1-1 Noji Higashi, Kusatsu, Shiga 525-8577 (Japan)] [WCU Hybrid Materials Program, Department of Materials Science and Engineering, Seoul National University, Seoul 151-744, South Korea and Research Organization of Science and Engineering, Ritsumeikan University, 1-1-1 Noji Higashi, Kusatsu, Shiga 525-8577 (Japan)

2013-01-21T23:59:59.000Z

45

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

SciTech Connect

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.

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

2012-12-24T23:59:59.000Z

46

Electronic structures and bonding properties of chlorine-treated nitrogenated carbon nanotubes: X-ray absorption and scanning photoelectron microscopy studies  

SciTech Connect

The electronic and bonding properties of nitrogenated carbon nanotubes (N-CNTs) exposed to chlorine plasma were investigated using C and N K-edge x-ray absorption near-edge structure (XANES) and scanning photoelectron microscopy (SPEM). The C and N K-edge XANES spectra of chlorine-treated N-CNTs consistently reveal the formation of pyridinelike N-CNTs by the observation of 1s{yields}{pi}*(e{sub 2u}) antibonding and 1s{yields}{pi}*(b{sub 2g}) bonding states. The valence-band photoemission spectra obtained from SPEM images indicate that chlorination of the nanotubes enhances the C-N bonding. First-principles calculations of the partial densities of states in conjunction with C K-edge XANES data identify the presence of C-Cl bonding in chlorine treated N-CNTs.

Ray, S. C.; Pao, C. W.; Tsai, H. M.; Chiou, J. W.; Pong, W. F.; Chen, C. W.; Tsai, M.-H.; Papakonstantinou, P.; Chen, L. C.; Chen, K. H.; Graham, W. G. [Department of Physics, Tamkang University, Tamsui 251, Taiwan (China); Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan (China); Department of Physics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); NRI, School of Electrical and Mechanical Engineering, University of Ulster at Jordanstown, Newtownabbey, County Antrim BT37OQB, Northern Ireland (United Kingdom); Center for Condensed Matter Sciences, National Taiwan University, Taipei 106, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Department of Physics and Astronomy, Queens University of Belfast, Belfast, Antrim BT71NN, Northern Ireland (United Kingdom)

2007-05-07T23:59:59.000Z

47

Kinetic study of GeO disproportionation into a GeO{sub 2}/Ge system using x-ray photoelectron spectroscopy  

SciTech Connect

GeO disproportionation into GeO{sub 2} and Ge is studied through x-ray photoelectron spectroscopy. Direct evidence for the reaction 2GeO {yields} GeO{sub 2} + Ge after annealing in ultra-high vacuum is presented. Activation energy for GeO disproportionation is found to be about 0.7 {+-} 0.2 eV through kinetic and thermodynamic calculations. A kinetic model of GeO disproportionation is established by considering oxygen transfer in the GeO network. The relationship between GeO disproportionation and GeO desorption induced by GeO{sub 2}/Ge interfacial reaction is discussed, and the apparent contradiction between GeO desorption via interfacial redox reaction and GeO disproportionation into Ge and GeO{sub 2} is explained by considering the oxygen vacancy.

Wang Shengkai [Micorowave Devices and Integrated Circuits Department, Institute of Microelectronics, Chinese Academy of Sciences, 3 Bei-Tu-Cheng West Road, Beijing 100029 (China); Department of Materials Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); CREST, Japan Science and Technology Agency (JST), 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Liu Honggang [Microwave Devices and Integrated Circuits Department, Institute of Microelectronics, Chinese Academy of Sciences, 3 Bei-Tu-Cheng West Road, Beijing 100029 (China); Toriumi, Akira [Department of Materials Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); CREST, Japan Science and Technology Agency (JST), 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

2012-08-06T23:59:59.000Z

48

The scanning soft X-ray microscope at Hasylab: imaging and spectroscopy of photoelectrons, photoluminescence, desorbed ions, reflected, scattered and transmitted light  

Science Journals Connector (OSTI)

The scanning soft X-ray microscope operating at Hasylab/Desy has been developed to combine lateral and temporal resolution, tunability and various conventional spectroscopy techniques. Different mirror optics are used to form a microprobe in the energy range 15–1500 eV. A grazing incidence ellipsoidal mirror provides a resolution of 1 ?m over the entire energy range, and in the vacuum ultraviolet region below 30 eV, 0.15 ?m can be achieved with a Pt-coated Schwarzschild objective. Due to the large working distance of the optics used, the detection and analysis of several surface signals are comparatively simple. Detectors and spectrometers for photoelectrons, luminescence, fluorescence, desorbed ions, reflected, scattered and transmitted light are built in permanently into the microscope. Furthermore, some combinations of the different methods can be used for simultaneous measurements. In this paper the technical developments of recent years are described. A short representation of some exemplary applications will give an insight into the work of our group and illustrate the characteristics of the microscope. The following topics are discussed: cross-luminescence of barium fluoride, visible luminescence and degradation of porous silicon, photoluminescence of ceramics, chemical contrast in photoemission spectroscopy, and Bragg reflection as a contrast mechanism in X-ray microscopy.

J Voss

1997-01-01T23:59:59.000Z

49

Direct observation of bias-dependence potential distribution in metal/HfO{sub 2} gate stack structures by hard x-ray photoelectron spectroscopy under device operation  

SciTech Connect

Although gate stack structures with high-k materials have been extensively investigated, there are some issues to be solved for the formation of high quality gate stack structures. In the present study, we employed hard x-ray photoelectron spectroscopy in operating devices. This method allows us to investigate bias dependent electronic states, while keeping device structures intact. Using this method, we have investigated electronic states and potential distribution in gate metal/HfO{sub 2} gate stack structures under device operation. Analysis of the core levels shifts as a function of the bias voltage indicated that a potential drop occurred at the Pt/HfO{sub 2} interface for a Pt/HfO{sub 2} gate structure, while a potential gradient was not observed at the Ru/HfO{sub 2} interface for a Ru/HfO{sub 2} gate structure. Angle resolved photoelectron spectroscopy revealed that a thicker SiO{sub 2} layer was formed at the Pt/HfO{sub 2} interface, indicating that the origin of potential drop at Pt/HfO{sub 2} interface is formation of the thick SiO{sub 2} layer at the interface. The formation of the thick SiO{sub 2} layer at the metal/high-k interface might concern the Fermi level pinning, which is observed in metal/high-k gate stack structures.

Yamashita, Y. [National Institute for Materials Science, Advanced Electric Materials Center, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); National Institute for Materials Science, NIMS Beamline Station at SPring-8, 1-1-1 Kôto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Yoshikawa, H.; Kobayashi, K. [National Institute for Materials Science, NIMS Beamline Station at SPring-8, 1-1-1 Kôto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Chikyo, T. [National Institute for Materials Science, Advanced Electric Materials Center, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

2014-01-28T23:59:59.000Z

50

Electronic structure of a PbFe1/2Nb1/2O3 single crystal in the ferroelectric and paraelectric states, according to X-Ray photoelectron spectroscopy data and first principle calculations  

Science Journals Connector (OSTI)

Electronic structure of the PbFe1/2Nb1/2O3 single crystal is studied by means of X-ray photoelectron spectroscopy on an ESCALAB 250 system and first principle FEFF9 at temperatures of 296 and 403 K.

A. T. Kozakov; O. E. Polozhentsev…

2012-10-01T23:59:59.000Z

51

Validity of automated x-ray photoelectron spectroscopy algorithm to determine the amount of substance and the depth distribution of atoms  

Science Journals Connector (OSTI)

The author reports a systematic study of the range of validity of a previously developed algorithm for automated x-ray photoelectron spectroscopy analysis which takes into account the variation in both peak intensity and the intensity in the background of inelastically scattered electrons. This test was done by first simulating spectra for the Au4d peak with gold atoms distributed in the form of a wide range of nanostructures which includes overlayers with varying thickness a 5?Å layer of atoms buried at varying depths and a substrate covered with an overlayer of varying thickness. Next the algorithm was applied to analyze these spectra. The algorithm determines the number of atoms within the outermost 3 ? of the surface. This amount of substance is denoted AOS 3 ? (where ?   is the electron inelastic mean free path). In general the determined AOS 3 ? is found to be accurate to within ?10–20% depending on the depth distribution of the atoms. The algorithm also determines a characteristic length L which was found to give unambiguous information on the depth distribution of the atoms for practically all studied cases. A set of rules for this parameter which relates the value of L to the depths where the atoms are distributed was tested and these rules were found to be generally valid with only a few exceptions. The results were found to be rather independent of the spectral energy range (from 20 to 40?eV below the peak energy) used in the analysis.

Sven Tougaard

2013-01-01T23:59:59.000Z

52

The evolution of Ga and As core levels in the formation of Fe/GaAs (001):A high resolution soft x-ray photoelectron spectroscopic study  

SciTech Connect

A high resolution soft x-ray photoelectron spectroscopic study of Ga and As 3d core levels has been conducted for Fe/GaAs (001) as a function of Fe thickness. This work has provided unambiguous evidence of substrate disrupting chemical reactions induced by the Fe overlayer--a quantitative analysis of the acquired spectra indicates significantly differing behavior of Ga and As during Fe growth, and our observations have been compared with existing theoretical models. Our results demonstrate that the outdiffusing Ga and As remain largely confined to the interface region, forming a thin intermixed layer. Whereas at low coverages Fe has little influence on the underlying GaAs substrate, the onset of substrate disruption when the Fe thickness reaches 3.5 Angstrom results in major changes in the energy distribution curves (EDCs) of both As and Ga 3d cores. Our quantitative analysis suggests the presence of two additional As environments of metallic character: one bound to the interfacial region and another which, as confirmed by in situ oxidation experiments, surface segregates and persists over a wide range of overlayer thickness. Analysis of the corresponding Ga 3d EDCs found not two, but three additional environments--also metallic in nature. Two of the three are interface resident whereas the third undergoes outdiffusion at low Fe coverages. Based on the variations of the integrated intensities of each component, we present a schematic of the proposed chemical makeup of the Fe/GaAs (001) system.

Thompson, Jamie; Neal, James; Shen, Tiehan; Morton, Simon; Tobin, James; Waddill, George Dan; Matthew, Jim; Greig, Denis; Hopkinson, Mark

2008-07-14T23:59:59.000Z

53

Kinetics of the sulfur oxidation on palladium: A combined in situ x-ray photoelectron spectroscopy and density-functional study  

SciTech Connect

We studied the reaction kinetics of sulfur oxidation on the Pd(100) surface by in situ high resolution x-ray photoelectron spectroscopy and ab initio density functional calculations. Isothermal oxidation experiments were performed between 400 and 500 K for small amounts ({approx}0.02 ML) of preadsorbed sulfur, with oxygen in large excess. The main stable reaction intermediate found on the surface is SO{sub 4}, with SO{sub 2} and SO{sub 3} being only present in minor amounts. Density-functional calculations depict a reaction energy profile, which explains the sequential formation of SO{sub 2}, SO{sub 3}, and eventually SO{sub 4}, also highlighting that the in-plane formation of SO from S and O adatoms is the rate limiting step. From the experiments we determined the activation energy of the rate limiting step to be 85 {+-} 6 kJ mol{sup -1} by Arrhenius analysis, matching the calculated endothermicity of the SO formation.

Gotterbarm, Karin; Hoefert, Oliver; Lorenz, Michael P. A.; Streber, Regine; Papp, Christian [Lehrstuhl fuer Physikalische Chemie II, Universitaet Erlangen-Nuernberg, Egerlandstr. 3, 91058 Erlangen (Germany); Luckas, Nicola; Vines, Francesc [Lehrstuhl fuer Theoretische Chemie, Universitaet Erlangen-Nuernberg, Egerlandstr. 3, 91058 Erlangen (Germany); Steinrueck, Hans-Peter [Lehrstuhl fuer Physikalische Chemie II, Universitaet Erlangen-Nuernberg, Egerlandstr. 3, 91058 Erlangen (Germany); Erlangen Catalysis Resource Center (ECRC), Universitaet Erlangen-Nuernberg, Egerlandstr. 3, 91058 Erlangen (Germany); Interdisciplinary Center for Interface Controlled Processes, Egerlandstr. 3, 91058 Erlangen (Germany); Goerling, Andreas [Lehrstuhl fuer Theoretische Chemie, Universitaet Erlangen-Nuernberg, Egerlandstr. 3, 91058 Erlangen (Germany); Interdisciplinary Center for Interface Controlled Processes, Egerlandstr. 3, 91058 Erlangen (Germany)

2012-03-07T23:59:59.000Z

54

Influence of electron irradiation and heating on secondary electron yields from non-evaporable getter films observed with in situ x-ray photoelectron spectroscopy  

SciTech Connect

Nonevaporable getter (NEG) film has been used for the beam ducts of particle accelerators as a pump having a large area. NEG film has been considered to have a low outgas rate induced by energetic particle irradiation and a low secondary electron yield (SEY). In this article, we focused on SEY measurements and in situ surface characterization of four NEG film samples using x-ray photoelectron spectroscopy (XPS). The NEG samples were TiZrV thin films deposited by magnetron sputtering at 100 or 300 deg. C on stainless steel. In addition, NEG samples saturated by CO gas exposure were prepared. SEY and XPS measurements of the surfaces of NEG samples were carried out under the conditions of as received, after electron beam irradiation, and after heating at 200 deg. C for 24 h. The maximum SEY values of the primary electron energy dependence, {delta}{sub max}, of all NEG samples decreased to around 1 by electron beam irradiation owing to a change in the carbon impurities, such as carbon oxide, carbon hydroxide, and hydrocarbon, to graphite state (graphitization) during the irradiation. After heating, {delta}{sub max} values of the NEG samples without CO gas exposure were also around 1 owing to the carbonization of Ti, Zr, and V. The {delta}{sub max}{approx_equal}1 was remarkably lower than that of copper baked under the same conditions. However, in saturated NEG samples, metal carbides were not produced to a significant extent by heating, and the {delta}{sub max} values did not decrease, showing values of 1.5-1.7.

Nishiwaki, Michiru; Kato, Shigeki [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan) and Department of Accelerator Science, The Graduate University for Advanced Studies, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)

2007-07-15T23:59:59.000Z

55

A Reactive Oxide Overlayer on Rh Nanoparticles during CO Oxidation and Its Size Dependence Studied by in Situ Ambient Pressure XPS  

SciTech Connect

CO oxidation is one of the most studied heterogeneous reactions, being scientifically and industrially important, particularly for removal of CO from exhaust streams and preferential oxidation for hydrogen purification in fuel cell applications. The precious metals Ru, Rh, Pd, Pt, and Au are most commonly used for this reaction because of their high activity and stability. Despite the wealth of experimental and theoretical data, it remains unclear what is the active surface for CO oxidation under catalytic conditions for these metals. In this communication, we utilize in situ synchrotron ambient pressure X-ray photoelectron spectroscopy (APXPS) to monitor the oxidation state at the surface of Rh nanoparticles during CO oxidation and demonstrate that the active catalyst is a surface oxide, the formation of which is dependent on particle size. The amount of oxide formed and the reaction rate both increase with decreasing particle size.

Grass, Michael E.; Zhang, Yawen; Butcher, Derek R.; Park, Jeong Y.; Li, Yimin; Bluhm, Hendrik; Bratlie, Kaitlin M.; Zhang, Tianfu; Somorjai, Gabor A.

2008-09-15T23:59:59.000Z

56

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

SciTech Connect

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

Tobin, J G

2011-03-17T23:59:59.000Z

57

X-ray photoelectron spectroscopy and structural analysis of amorphous SiO{sub x}N{sub y} films deposited at low temperatures  

SciTech Connect

We establish, using a tetrahedral model, the bonding properties of amorphous silicon oxynitride (a-SiO{sub x}N{sub y}) films deposited at low temperatures (LTs) by electron-cyclotron resonance chemical-vapor deposition (ECRCVD) on several substrates and under various conditions of gas flows and total gas pressure in a dilute mixture of SiH{sub 4}+N{sub 2} in Ar. The atomic percentage of each tetrahedral unit incorporated in the film network is calculated from the deconvolution of the high-resolution x-ray photoelectron spectroscopy (XPS) spectra in the Si 2p{sub 3/2} region and corroborated by the results obtained from both survey scans and the high-resolution XPS spectra in the N 1s region. The Si{sub 3}N{sub 4} phase is the most important one and the only bonding unit which is incorporated in all our LT ECRCVD SiO{sub x}N{sub y} films. The incorporation of all the other component tetrahedrons depends strongly on growth conditions. The threshold values of the N/Si atomic ratio for which intrinsic defects, such as Si-Si bonds, are not incorporated in the network depend on the O/Si ratio incorporated in the films, mainly due to the competition between oxygen and nitrogen atoms in their reaction with silicon dangling bonds. The effect of the total gas pressure on the atomic percentages of the oxidation states present in the LT ECRCVD SiO{sub x}N{sub y} films is qualitatively similar to the effect of the ion bombarding energy or the plasma density. O-N bonds are present only in samples having high amount of oxygen and nitrogen in their networks. For these films, our results show unambiguously the presence of the N-Si{sub 2}O tetrahedron and suggest that N-Si{sub 3-{nu}}O{sub {nu}} tetrahedrons with {nu}{>=}2 are not incorporated in their networks. A correlation is observed between the N-Si{sub 2}O and the Si-O{sub 3}(ON) tetrahedrons whose component peak is localized at (104.0{+-}0.2) eV in the Si 2p{sub 3/2} region of the XPS data, which suggests that both bonding units coexist in these films as some sort of complex bonding configuration.

Cova, P.; Poulin, S.; Masut, R.A. [Departmento de Fisica, Laboratorio de Simulacion de Dispositivos Semiconductores, Universidad de Oriente, Apartado 124, Cumana 6101, Sucre (Venezuela); Regroupement Quebecois sur les Materiaux de Pointe (RQMP) and Departement de Genie Physique, Ecole Polytechnique, C.P. 6079, succ. Centre-ville, Montreal, Quebec H3C 3A7 (Canada)

2005-11-01T23:59:59.000Z

58

Photoelectron Spectroscopy under Ambient Pressure and Temperature Conditions  

E-Print Network (OSTI)

Rev. 99 , 77 (1999). Peltier source & model FTS systemsgas environments. Peltier sample holder We constructed abased on a thermoelectric Peltier cooler for experiments in

Ogletree, D. Frank

2009-01-01T23:59:59.000Z

59

Photoelectron Spectroscopy under Ambient Pressure and Temperature Conditions  

E-Print Network (OSTI)

than ~ 100 l/s in a typical UHV system, so this produces aof spectroscopy chamber p 0 = UHV…~ torr preparation chamberpumping system was capable of UHV performance and maintained

Ogletree, D. Frank

2009-01-01T23:59:59.000Z

60

Chemical reactions at Cu/ZnS(001) and In/ZnS(001) heterojunctions: A comparison of photoelectron and S L{sub 2,3} x-ray emission spectroscopy  

SciTech Connect

Occurrence and extent of chemical reactions at Cu/ZnS(001) and In/ZnS(001) heterojunctions have been investigated by S L{sub 2,3} x-ray emission spectroscopy as well as photoelectron spectroscopy. With the formation of metal-sulfur bonds, spectral features originating from shallow metal d core levels (Zn 3d, In 4d) or valence states (Cu 3d)) may appear in the S L{sub 2,3} emission spectra. Thus the x-ray emission spectroscopy was employed to detect chemical reactions at the heterojunctions, together with conventional photoelectron spectroscopy. Considerable reactions at the Cu/ZnS(001) interface are more clearly indicated in the S L emission spectrum than in the Cu 2p{sub 3sol2} or S 2p core level spectra, whereas relatively confined reactions at the In/ZnS(001) interface can only be probed in the In 3d{sub 5sol2} core level spectra. The partial densities of states calculated for a reference CuInS{sub 2} on the basis of density functional theory agree well with features occurring in its S L{sub 2,3} emission spectrum.

Zhang, L.; Wett, D.; Schulze, D.; Szargan, R.; Nagel, M.; Peisert, H.; Chasse, T. [Institut fuer Physikalische und Theoretische Chemie, Universitaet Tuebingen, Auf der Morgenstelle 8, 72076 Tuebingen (Germany); Wilhelm-Ostwald-Institut fuer Physikalische und Theoretische Chemie, Universitaet Leipzig, Linnestrasse 2, 04103 Leipzig (Germany); Wilhelm-Ostwald-Institut fuer Physikalische und Theoretische Chemie, Universitaet Leipzig, Linnestrasse 2, 04103 Leipzig (Germany); Institut fuer Physikalische und Theoretische Chemie, Universitaet Tuebingen, Auf der Morgenstelle 8, 72076 Tuebingen (Germany)

2005-01-03T23:59:59.000Z

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

A combined droplet train and ambient pressure photoemission spectrometer for the investigation of liquid/vapor interfaces  

SciTech Connect

We describe a combined ambient pressure photoelectron spectroscopy/droplet train apparatus for investigating the nature and heterogeneous chemistry of liquid/vapor interfaces. In this instrument a liquid droplet train with typical droplet diameters from 50...150 {micro}m is produced by a vibrating orifice aerosol generator (VOAG). The droplets are irradiated by soft X-rays (100...1500 eV) in front of the entrance aperture of a differentially pumped electrostatic lens system that transfers the emitted electrons into a conventional hemispherical electron analyzer. The photoemission experiments are performed at background pressures of up to several Torr, which allows the study of environmentally important liquid/vapor interfaces, in particular aqueous solutions, under equilibrium conditions. The exposure time of the droplet surface to the background gases prior to the XPS measurement can be varied, which will allow future kinetic measurements of gas uptake on liquid surfaces. As an example, a measurement of the surface composition of a {chi} = 0.21 aqueous methanol solution is presented. The concentration of methanol at the vapor/liquid interface is enhanced by a factor of about 3 over the bulk value, while the expected bulk value is recovered at depths larger than about 1.5 nm.

Starr, David E.; Wong, Ed K.; Worsnop, Douglas R.; Wilson, Kevin R.; Bluhm, Hendrik

2008-05-01T23:59:59.000Z

62

Microgap x-ray detector  

DOE Patents (OSTI)

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.

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

1994-01-01T23:59:59.000Z

63

Band alignment of HfO{sub 2}/Al{sub 0.25}Ga{sub 0.75}N determined by x-ray photoelectron spectroscopy: Effect of SiH{sub 4} surface treatment  

SciTech Connect

The band-alignment of atomic layer deposited (ALD)-HfO{sub 2}/Al{sub 0.25}Ga{sub 0.75}N was studied by high resolution x-ray photoelectron spectroscopy measurements for both the non-passivated and SiH{sub 4} passivated AlGaN surfaces. The valence band offset and the conduction band offset for the ALD-HfO{sub 2}/Al{sub 0.25}Ga{sub 0.75}N interface were found to be 0.43?eV and 1.47?eV, respectively, for the non-passivated sample, and 0.59?eV and 1.31?eV, respectively, for the SiH{sub 4}-passivated sample. The difference in the band alignment is dominated by the band bending or band shift in the AlGaN substrate as a result of the different interlayers formed by the two surface preparations.

Samuel Owen, Man Hon, E-mail: m.owen.sg@ieee.org, E-mail: yeo@ieee.org; Amin Bhuiyan, Maruf; Zhou, Qian; Yeo, Yee-Chia, E-mail: m.owen.sg@ieee.org, E-mail: yeo@ieee.org [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 119260 (Singapore); Zhang, Zheng; Sheng Pan, Ji [Institute of Materials Research and Engineering, A-STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 (Singapore)

2014-03-03T23:59:59.000Z

64

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

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.

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

2014-05-28T23:59:59.000Z

65

Effect of Ambient Pressure on Diesel Spray Axial Velocity and...  

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

deer07kastengren.pdf More Documents & Publications Spray Structure Measured with X-Ray Radiography Ultrafast X-ray Phase-Enhanced Microimaging for Visualizing Fuel Injection...

66

E-Print Network 3.0 - ambient pressure estimation Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

at ambient pressure. That is confirmed from the transition temperature TN vs pressure phase... was observed at ambient pressure 6. Along with the data indicating relatively...

67

X-ray induced optical reflectivity  

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

Durbin, Stephen M.

2012-01-01T23:59:59.000Z

68

Chest x-Rays  

Energy.gov (U.S. Department of Energy (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.

69

X-ray beamsplitter  

DOE Patents (OSTI)

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.

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

1987-08-07T23:59:59.000Z

70

X-ray beamsplitter  

DOE Patents (OSTI)

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.

Ceglio, Natale M. (Livermore, CA); Stearns, Daniel S. (Mountain View, CA); Hawryluk, Andrew M. (Modesto, CA); Barbee, Jr., Troy W. (Palo Alto, CA)

1989-01-01T23:59:59.000Z

71

X-ray binaries  

E-Print Network (OSTI)

We review the nuclear astrophysics aspects of accreting neutron stars in X-ray binaries. We summarize open astrophysical questions in light of recent observations and their relation to the underlying nuclear physics. Recent progress in the understanding of the nuclear physics, especially of X-ray bursts, is also discussed.

H. Schatz; K. E. Rehm

2006-08-01T23:59:59.000Z

72

X-ray radiation effects in multilayer epitaxial graphene Jeremy Hicks1  

E-Print Network (OSTI)

1 X-ray radiation effects in multilayer epitaxial graphene Jeremy Hicks1 , Rajan Arora2 , Eleazar and after exposure to a total ionizing dose (TID) of 12 Mrad(SiO2) using a 10 keV X-ray source. While we are mostly unaffected by radiation exposure. Combined with X-ray photoelectron spectroscopy (XPS) data

73

X-ray laser  

DOE Patents (OSTI)

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.

Nilsen, Joseph (Livermore, CA)

1991-01-01T23:59:59.000Z

74

X-ray absorption spectroscopy  

E-Print Network (OSTI)

009-9473-8 REVIEW X-ray absorption spectroscopy Junko Yano Æand application of X-ray absorption spectroscopy, bothX-ray absorption near-edge structure (XANES) and extended X-

Yano, Junko; Yachandra, Vittal K.

2009-01-01T23:59:59.000Z

75

X-ray Absorption Spectroscopy  

E-Print Network (OSTI)

type: Review X-ray Absorption Spectroscopy Junko Yano andPhotosystem II; XAS, X-ray absorption spectroscopy; EXAFS,X-ray absorption fine structure; EPR, electron paramagnetic

Yano, Junko

2010-01-01T23:59:59.000Z

76

X-Ray Generators  

Science Journals Connector (OSTI)

There are many types of X-ray generators sold commercially. The following are some of ... that should be considered when selecting a particular generator for a particular purpose. All the companies listed below s...

Reuben Rudman

1972-01-01T23:59:59.000Z

77

Direct Observation of Decoupled Structural and Electronic Transitions and an Ambient Pressure Monocliniclike Metallic Phase of VO2  

Science Journals Connector (OSTI)

We report the simultaneous measurement of the structural and electronic components of the metal-insulator transition (MIT) of VO2 using electron and photoelectron spectroscopies and microscopies. We show that these evolve over different temperature scales, and are separated by an unusual monocliniclike metallic phase. Our results provide conclusive evidence that the new monocliniclike metallic phase, recently identified in high-pressure and nonequilibrium measurements, is accessible in the thermodynamic transition at ambient pressure, and we discuss the implications of these observations on the nature of the MIT in VO2.

J. Laverock; S. Kittiwatanakul; A.?A. Zakharov; Y.?R. Niu; B. Chen; S.?A. Wolf; J.?W. Lu; K.?E. Smith

2014-11-17T23:59:59.000Z

78

Spectroscopic imaging, diffraction, and holography with x-ray photoemission  

SciTech Connect

X-ray probes are capable of determining the spatial structure of an atom in a specific chemical state, over length scales from about a micron all the way down to atomic resolution. Examples of these probes include photoemission microscopy, energy-dependent photoemission diffraction, photoelectron holography, and X-ray absorption microspectroscopy. Although the method of image formation, chemical-state sensitivity, and length scales can be very different, these X-ray techniques share a common goal of combining a capability for structure determination with chemical-state specificity. This workshop will address recent advances in holographic, diffraction, and direct imaging techniques using X-ray photoemission on both theoretical and experimental fronts. A particular emphasis will be on novel structure determinations with atomic resolution using photoelectrons.

Not Available

1992-02-01T23:59:59.000Z

79

X-ray beam finder  

DOE Patents (OSTI)

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.

Gilbert, H.W.

1983-06-16T23:59:59.000Z

80

X-ray Spectrometry  

Science Journals Connector (OSTI)

These provide excellent energy resolution for a wide range of X-ray energies, from the optical range up to several kiloelectronvolts. ... The Astro-E2 launched in 2005 was the first mission that contained a low-temperature microcalorimeter-based observatory, and three more low-temperature detector-based observatories are being developed (NeXT, Constellation-X, ZEUS). ...

Imre Szalóki; János Osán; René E. Van Grieken

2006-05-10T23:59:59.000Z

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Tunable X-ray source  

DOE Patents (OSTI)

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.

Boyce, James R. (Williamsburg, VA)

2011-02-08T23:59:59.000Z

82

X-ray Spectrometry  

Science Journals Connector (OSTI)

The segmented STJ operated at total count rates of above 105 counts/s, and the best-achieved energy resolution of their single STJ was found to be 10 eV for X-ray energies below 1 keV. ... The Mo?Au TES, with an operating temperature of 230 mK, was developed for the Constellation-X mission and the energy resolution of the spectrometer is ?28 eV at 3.3 keV. ...

Imre Szalóki; Szabina B. Török; Jasna Injuk; René E. Van Grieken

2002-05-18T23:59:59.000Z

83

Rotational Doppler effect in x-ray photoionization  

SciTech Connect

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

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

2010-11-15T23:59:59.000Z

84

Rotational Doppler effect in x-ray photoionization  

Science Journals Connector (OSTI)

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

Yu-Ping Sun; Chuan-Kui Wang; Faris Gel’mukhanov

2010-11-10T23:59:59.000Z

85

X-ray Absorption Spectroscopy  

SciTech Connect

This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.

Yano, Junko; Yachandra, Vittal K.

2009-07-09T23:59:59.000Z

86

X-ray fluorescence mapping  

NLE Websites -- All DOE Office Websites (Extended Search)

biololgical cells, over the measurement of impurities in solar cells, to the rare earth content of geological materials. A somewhat 'typical' layout for a X-ray fluorescence...

87

Cryogenic x-ray diffraction microscopy utilizing high-pressure cryopreservation  

Science Journals Connector (OSTI)

We present cryo x-ray diffraction microscopy of high-pressure-cryofixed bacteria and report high-convergence imaging with multiple image reconstructions. Hydrated D. radiodurans cells were cryofixed at 200 MPa pressure into ?10??m-thick water layers and their unstained, hydrated cellular environments were imaged by phasing diffraction patterns, reaching sub-30-nm resolutions with hard x-rays. Comparisons were made with conventional ambient-pressure-cryofixed samples, with respect to both coherent small-angle x-ray scattering and the image reconstruction. The results show a correlation between the level of background ice signal and phasing convergence, suggesting that phasing difficulties with frozen-hydrated specimens may be caused by high-background ice scattering.

Enju Lima; Yuriy Chushkin; Peter van der Linden; Chae Un Kim; Federico Zontone; Philippe Carpentier; Sol M. Gruner; Petra Pernot

2014-10-15T23:59:59.000Z

88

X-ray shearing interferometer  

DOE Patents (OSTI)

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.

Koch, Jeffrey A. (Livermore, CA)

2003-07-08T23:59:59.000Z

89

X-ray microscopy: An emerging technique for semiconductor microstructure characterization  

SciTech Connect

The advent of third generation synchrotron radiation x-ray sources, such as the Advanced Light Source (ALS) at Berkeley have enabled the practical realization of a wide range of new techniques in which mature chemical or structural probes such as x-ray photoelectron spectroscopy (XPS) and x-ray diffraction are used in conjunction with microfocused x-ray beams. In this paper the characteristics of some of these new microscopes are described, particularly in reference to their applicability to the characterization of semiconductor microstructures.

Padmore, H.A.

1998-05-01T23:59:59.000Z

90

Optics for X-Ray Laser and Laser Plasma Soft X-Ray Radiation  

Science Journals Connector (OSTI)

Focusing X-ray grazing incidence optics for X-ray laser and laser plasma soft X-ray radiation has been studied. ... computer code. Parabolic axisymmetric mirror for focusing Princeton X-ray laser beam and ellipso...

L. Pina; A. Inneman; R. Hudec

1996-01-01T23:59:59.000Z

91

SMB, X-Ray Spectroscopy & Imaging  

NLE Websites -- All DOE Office Websites (Extended Search)

Home X-Ray Spectroscopy & Imaging X-Ray Spectroscopy & Imaging SSRL has five hard X-ray Spectroscopy beamlines and three Microfocus Imaging beamlines dedicated to Biological and...

92

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (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...

93

X-ray Imaging Workshop  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging and Spectro-microscopy: 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 electron microscopy (PEEM), angle resolved photoemission spectroscopy (ARPES), coherent diffraction imaging, x-ray microscopy, micro-tomography, holographic imaging, and x-ray micro-probe. Twelve invited speakers discussed the important scientific applications of these techniques, and also predicted the future scientific directions with the advance of instrumentation and x-ray sources. The workshop was well attended with over fifty registered attendees.

94

Miniature x-ray source  

DOE Patents (OSTI)

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.

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

2000-01-01T23:59:59.000Z

95

Center for X-Ray Optics, 1992  

SciTech Connect

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

Not Available

1993-08-01T23:59:59.000Z

96

X-ray Stacking 2008-Apr-22 Astrostats X-ray Stacking  

E-Print Network (OSTI)

X-ray Stacking 2008-Apr-22 Astrostats X-ray Stacking Tom Aldcroft SAO/CXC #12;X-ray Stacking 2008 analysis for a sample Stacking ­ mean properties of sample Chandra X-ray data (faint point sources) are photon-limited with low background => stacking in X-rays is very effective #12;X-ray Stacking 2008-Apr-22

Wolfe, Patrick J.

97

Single- and few-layer graphene by ambient pressure chemical vapor deposition on nickel  

E-Print Network (OSTI)

An ambient pressure chemical vapor deposition (APCVD) process is used to fabricate graphene based films consisting of one to several graphene layers across their area. Polycrystalline Ni thin films are used and the graphene ...

Reina Ceeco, Alfonso

2010-01-01T23:59:59.000Z

98

RYLLA. [X-ray transport code  

SciTech Connect

This paper describes a computer code, RYLLA, which models the deposition of x-rays into thin metal slabs, and transports the resulting photoelectrons, finding the distribution of electrons leaving the slab from both the front and back surfaces. The slab must be homogeneous, but can contain a mixture of up to 5 different elements. Due to the short electron mean free path at low electron energies, RYLLA should be used only for studying thin slabs, roughly < 100 mg/cm/sup 2/ for low Z metals, and < 10 mg/cm/sup 2/ for high Z metals. X-ray energies should be in the range of 1 to 150 keV, as they are deposited only via photoionization and Compton scattering processes. Following photoionization, a hole exists in the electron cloud of the absorbing atom. This fills either by Auger or fluoresence, resulting in lower energy holes which are also filled. Fluoresence photons are transported and absorbed in the same manner as the primary photons, except that they are isotropically produced. Once all photons have been transported and absorbed, and all holes have been filled, a space- and energy-dependent electron source spectrum has been obtained. This is used in a discrete ordinate expansion solution of the 1-D transport equation, which gives the output electron spectra at the two slab surfaces. This paper discusses both the physics and coding of RYLLA. Examples of user input are given, as are some comparisons with other codes.

Hyde, R.A.

1983-06-08T23:59:59.000Z

99

Center for X-Ray Optics, 1991  

SciTech Connect

This report discusses: Soft-X-Ray imaging with zone-plate lenses; multilayer reflective optics; and spectroscopy with x-rays.

Not Available

1992-03-01T23:59:59.000Z

100

SMB, X-ray Absorption Spectroscopy  

NLE Websites -- All DOE Office Websites (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...

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Tokamak x ray diagnostic instrumentation  

SciTech Connect

Three classes of x-ray diagnostic instruments enable measurement of a variety of tokamak physics parameters from different features of the x-ray emission spectrum. (1) The soft x-ray (1 to 50 keV) pulse-height-analysis (PHA) diagnostic measures impurity concentrations from characteristic line intensities and the continuum enhancement, and measures the electron temperature from the continuum slope. (2) The Bragg x-ray crystal spectrometer (XCS) measures the ion temperature and neutral-beam-induced toroidal rotation velocity from the Doppler broadening and wavelength shift, respectively, of spectral lines of medium-Z impurity ions. Impurity charge state distributions, precise wavelengths, and inner-shell excitation and recombination rates can also be studied. X rays are diffracted and focused by a bent crystal onto a position-sensitive detector. The spectral resolving power E/..delta..E is greater than 10/sup 4/ and time resolution is 10 ms. (3) The x-ray imaging system (XIS) measures the spatial structure of rapid fluctuations (0.1 to 100 kHZ) providing information on MHD phenomena, impurity transport rates, toroidal rotation velocity, plasma position, and the electron temperature profile. It uses an array of silicon surface-barrier diodes which view different chords of the plasma through a common slot aperture and operate in current (as opposed to counting) mode. The effectiveness of shields to protect detectors from fusion-neutron radiation effects has been studied both theoretically and experimentally.

Hill, K.W.; Beiersdorfer, P.; Bitter, M.; Fredrickson, E.; Von Goeler, S.; Hsuan, H.; Johnson, L.C.; Liew, S.L.; McGuire, K.; Pare, V.

1987-01-01T23:59:59.000Z

102

Scanning X-ray Photoelectron Spectrometer Microprobe | EMSL  

NLE Websites -- All DOE Office Websites (Extended Search)

initiated immobilization. Using a... Single-step conversion of cellulose to 5-hydroxymethylfurfural (HMF), a versatileplatform chemical. The ability to use cellulosic biomass as...

103

X-ray Emission from Massive Stars  

E-Print Network (OSTI)

X-ray Emission from Massive Stars David Cohen Department of Physics and Astronomy Swarthmore be related to the production of X-rays on massive stars. If so, massive stars' X-rays are much different than those found our own Sun and other cooler stars like the Sun that produce X-rays via magnetic activity

Cohen, David

104

X-ray Emission from Massive Stars  

E-Print Network (OSTI)

X-ray Emission from Massive Stars David Cohen Department of Physics and Astronomy Swarthmore #12;What is the mechanism by which massive stars produce x-rays? New results from the Chandra X-ray Observatory ­ high-resolution x-ray spectroscopy: measuring Doppler broadening in emission lines Testing

Cohen, David

105

Microsoft Word - ArtificialPhotosynthesis bh  

NLE Websites -- All DOE Office Websites (Extended Search)

electrochemical cell setup for ambient- pressure XPS investigations of artificial photosynthesis process In Situ X-ray Photoelectron Spectroscopy of a Catalyst for Artificial...

106

Compact x-ray source and panel  

DOE Patents (OSTI)

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.

Sampayon, Stephen E. (Manteca, CA)

2008-02-12T23:59:59.000Z

107

Ultrafast X-ray Absorption Spectroscopy using Laser-Driven Electron X-ray Sources (LEXS)  

E-Print Network (OSTI)

: ultrafast x-rays, x-ray absorption spectroscopy, terawatt lasers, ultrafast reaction dynamics, atomic motion atomic motion by scrutinizing the changes in x- ray absorption spectra during reactions. FirstUltrafast X-ray Absorption Spectroscopy using Laser-Driven Electron X-ray Sources (LEXS) Guangjun

Guo, Ting

108

Focused X-ray source  

DOE Patents (OSTI)

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.

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

1990-08-21T23:59:59.000Z

109

A combined droplet train and ambient pressure photoemission spectrometer for the investigation of liquid/vapor interfaces  

E-Print Network (OSTI)

A combined droplet train and ambient pressure photoemissionspectroscopy/droplet train apparatus for investigating thethis instrument a liquid droplet train with typical droplet

Starr, David E.

2008-01-01T23:59:59.000Z

110

Chest x-Rays | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Chest x-Rays Chest x-Rays Chest x-Rays Chest X-ray B-Reading 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. The B-reading is considered a special reading because doctors who are certified by NIOSH to perform B-readings use a specific protocol to read and record the findings as developed by the International Labour Organization (ILO). The ILO's protocol provides rules for systematically examining the x-ray in a step-by-step method and recording certain abnormalities or changes on the chest x-ray that can be attributable to

111

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (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...

112

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

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...

113

Producing X-rays at the APS  

ScienceCinema (OSTI)

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.

None

2013-04-19T23:59:59.000Z

114

SMB, X-ray Fluorescence Imaging  

NLE Websites -- All DOE Office Websites (Extended Search)

Fluorescence Imaging X-ray Fluorescence Imaging X-ray fluorescence imaging utilizes the high brightness of SPEAR3 and focused beam generated by the uses of K-B optics, capillaries...

115

Silica–titania aerogel monoliths with large pore volume and surface area by ambient pressure drying  

Science Journals Connector (OSTI)

Ambient pressure drying has been carried out for the synthesis of silica–titania aerogel monoliths. The prepared aerogels show densities in the range 0.34–0.38 g/cm3. The surface area and pore volume of these mix...

P. R. Aravind; P. Shajesh; P. Mukundan…

2009-12-01T23:59:59.000Z

116

Synthesis of Graphene Films by Rapid Heating and Quenching at Ambient Pressures and Their Electrochemical Characterization  

E-Print Network (OSTI)

-ion battery 1. INTRODUCTION Atomically thin two-dimensional honeycomb lattice structure of graphene and itsSynthesis of Graphene Films by Rapid Heating and Quenching at Ambient Pressures, Michigan 48109, United States *S Supporting Information ABSTRACT: We study the process of graphene growth

Zhong, Zhaohui

117

Chandra X-ray Observatory Center  

E-Print Network (OSTI)

Chandra X-ray Observatory Center Harvard-Smithsonian Center for Astrophysics 60 Garden St in hot gas about 250 million light years from Earth. (Credit: X-ray: NASA/CXC/SAO/E.Bulbul, et al-Newton has revealed a mysterious X-ray signal in the data. This signal is represented in the circled data

118

X-Ray Absorption Spectroscopy of Metallobiomolecules  

E-Print Network (OSTI)

2/9/07 1 X-Ray Absorption Spectroscopy of Metallobiomolecules The Outskirts of Structural Biology 9, 07] This is a tutorial about the use of X-ray Absorption Spectroscopy (XAS) in biology, RG; Eisenberger, P; Kincaid, BM "X-ray Absorption Spectroscopy of Biological Molecules" Annu. Rev

Scott, Robert A.

119

Chandra X-ray Observatory Center  

E-Print Network (OSTI)

Chandra X-ray Observatory Center Harvard-Smithsonian Center for Astrophysics 60 Garden St million light years from Earth. (Credit: X-ray: NASA/CXC/Wesleyan Univ./R.Kilgard, et al; Optical: NASA with optical data from the Hubble Space Telescope (red, green, and blue). The X-ray data reveal hundreds

120

X-ray Spectroscopy of Cool Stars  

E-Print Network (OSTI)

High-resolution X-ray spectroscopy has addressed not only various topics in coronal physics of stars, but has also uncovered important features relevant for our understanding of stellar evolution and the stellar environment. I summarize recent progress in coronal X-ray spectroscopy and in particular also discuss new results from studies of X-rays from pre-main sequence stars.

M. Guedel

2006-09-11T23:59:59.000Z

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

X-Ray Physics Evan Berkowitz  

E-Print Network (OSTI)

X-Ray Physics Evan Berkowitz Junior, MIT Department of Physics (Dated: October 25, 2006) We measure a variety of phenomena related to X-Ray absorption and production. We present data which conforms within, as are 22 Na electron-positron annhilation lines. The importance of understanding x-rays is demonstrated

122

Chandra X-ray Observatory Center  

E-Print Network (OSTI)

Chandra X-ray Observatory Center Harvard-Smithsonian Center for Astrophysics 60 Garden St 200 million light years from Earth. (Credit: X-ray: NASA/CXC/UAH/M.Sun et al; Optical: NASA, ESA, & the Hubble Heritage Team (STScI/AURA) Caption: This composite image from the Chandra X-ray Observatory (blue

123

X-Ray Absorption Spectroscopy of Metallobiomolecules  

E-Print Network (OSTI)

9/6/09 1 X-Ray Absorption Spectroscopy of Metallobiomolecules The Outskirts of Structural Biology 6, 09] This is a tutorial about the use of X-ray Absorption Spectroscopy (XAS) in biology, RG; Eisenberger, P; Kincaid, BM "X-ray Absorption Spectroscopy of Biological Molecules" Annu. Rev

Scott, Robert A.

124

Chandra X-ray Observatory Center  

E-Print Network (OSTI)

Chandra X-ray Observatory Center Harvard-Smithsonian Center for Astrophysics 60 Garden St. Cambridge, MA 02138 USA http://chandra.harvard.edu Four Supernova Remnants: NASA's Chandra X-ray Observatory's Chandra X-ray Observatory, four newly processed images of supernova remnants dramatically illustrate

125

Using Light to Control How X Rays Interact with Matter  

NLE Websites -- All DOE Office Websites (Extended Search)

ultrafast x-ray spectroscopy. ALS femtosecond spectroscopy beamline layout. Femtosecond x-ray and laser pulses derive from a single 800-nm laser oscillator. Femtosecond x rays...

126

X-RAY SPECTROMETRY X-Ray Spectrom. 2007; 36: 336342  

E-Print Network (OSTI)

X-RAY SPECTROMETRY X-Ray Spectrom. 2007; 36: 336­342 Published online in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/xrs.980 Fish otolith trace element maps: new approaches with synchrotron microbeam x-ray of elements as they accrete through a fish's life. We apply synchrotron microbeam x-ray fluorescence methods

Limburg, Karin E.

127

X-ray Pulsations in the Supersoft X-ray Binary CAL 83  

E-Print Network (OSTI)

X-ray data reveal that the supersoft X-ray binary CAL 83 exhibits 38.4 minute pulsations at some epochs. These X-ray variations are similar to those found in some novae and are likely to be caused by nonradial pulsations the white dwarf. This is the first detection of pulsations in a classical supersoft X-ray binary.

P. C. Schmidtke; A. P. Cowley

2005-09-28T23:59:59.000Z

128

X-ray Spectroscopy of Cooling Cluster  

SciTech Connect

We review the X-ray spectra of the cores of clusters of galaxies. Recent high resolution X-ray spectroscopic observations have demonstrated a severe deficit of emission at the lowest X-ray temperatures as compared to that expected from simple radiative cooling models. The same observations have provided compelling evidence that the gas in the cores is cooling below half the maximum temperature. We review these results, discuss physical models of cooling clusters, and describe the X-ray instrumentation and analysis techniques used to make these observations. We discuss several viable mechanisms designed to cancel or distort the expected process of X-ray cluster cooling.

Peterson, J.R.; /SLAC; Fabian, A.C.; /Cambridge U., Inst. of Astron.

2006-01-17T23:59:59.000Z

129

X-ray transmissive debris shield  

DOE Patents (OSTI)

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.

Spielman, R.B.

1996-05-21T23:59:59.000Z

130

X-ray Spectroscopy of Cooling Clusters  

E-Print Network (OSTI)

We review the X-ray spectra of the cores of clusters of galaxies. Recent high resolution X-ray spectroscopic observations have demonstrated a severe deficit of emission at the lowest X-ray temperatures as compared to that expected from simple radiative cooling models. The same observations have provided compelling evidence that the gas in the cores is cooling below half the maximum temperature. We review these results, discuss physical models of cooling clusters, and describe the X-ray instrumentation and analysis techniques used to make these observations. We discuss several viable mechanisms designed to cancel or distort the expected process of X-ray cluster cooling.

J. R. Peterson; A. C. Fabian

2005-12-21T23:59:59.000Z

131

X-ray transmissive debris shield  

DOE Patents (OSTI)

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.

Spielman, Rick B. (Albuquerque, NM)

1996-01-01T23:59:59.000Z

132

X-ray lithography using holographic images  

DOE Patents (OSTI)

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.

Howells, Malcolm R. (Berkeley, CA); Jacobsen, Chris (Sound Beach, NY)

1995-01-01T23:59:59.000Z

133

Core Level Spectroscopies Surface Science and X-Ray Spectroscopy Group  

NLE Websites -- All DOE Office Websites (Extended Search)

Core Level Spectroscopy Creation and Decay of Core Holes Spectroscopic Techniques X-ray Photoelectron (XPS) X-ray Absorption (XAS) X-ray Emission (XES) Auger Electron (AES) Core holes are created by the ionization of a core electron in XPS and by excitation in XAS . The XPS and XAS final states are highly unstable and the core hole decays by non-radiant Auger relaxation (AES) or by radiant x-ray emission processes (XES). XPS and AES probe the unoccupied electronic stru cture, while XAS projects the unoccupied valence states of the system onto a particular atom. A brief description of the each of the different spectroscopies illustrated by schematic pictures of the creation and decay with data measured for N2 adsorbed on Ni(100) can be found by scrolling

134

X-ray Observations of Mrk 231  

E-Print Network (OSTI)

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

T. J. Turner

1998-08-10T23:59:59.000Z

135

Chemistry of NOx on TiO2 surfaces studied by ambient pressure XPS:  

NLE Websites -- All DOE Office Websites (Extended Search)

Chemistry of NOx on TiO2 surfaces studied by ambient pressure XPS: Chemistry of NOx on TiO2 surfaces studied by ambient pressure XPS: products, effect of UV irradiation, water and coadsorbed K+ Title Chemistry of NOx on TiO2 surfaces studied by ambient pressure XPS: products, effect of UV irradiation, water and coadsorbed K+ Publication Type Journal Article Year of Publication 2013 Authors Rosseler, Olivier, Mohamad Sleiman, Nahuel V. Montesinos, Andrey Shavorskiy, Valerie Keller, Nicolas Keller, Marta I. Litter, Hendrik Bluhm, Miquel Salmeron, and Hugo Destaillats Journal J. Phys. Chem. Lett. Volume 4 Start Page 536 Issue 3 Pagination 536-541 Date Published 01/2013 Abstract Self-cleaning surfaces containing TiO2 nanoparticles have been postulated to efficiently remove NOx from the atmosphere. However, UV irradiation of NOx adsorbed on TiO2 also was shown to form harmful gas-phase byproducts such as HONO and N2O that may limit their depolluting potential. Ambient pressure XPS was used to study surface and gas-phase species formed during adsorption of NO2 on TiO2 and subsequent UV irradiation at λ = 365 nm. It is shown here that NO3-, adsorbed on TiO2 as a byproduct of NO2 disproportionation, was quantitatively converted to surface NO2 and other reduced nitrogenated species under UV irradiation in the absence of moisture. When water vapor was present, a faster NO3- conversion occurred, leading to a net loss of surface-bound nitrogenated species. Strongly adsorbed NO3- in the vicinity of coadsorbed K+ cations was stable under UV light, leading to an efficient capture of nitrogenated compounds.

136

Hard x-ray imaging from explorer  

SciTech Connect

Coded aperture X-ray detectors were applied to obtain large increases in sensitivity as well as angular resolution. A hard X-ray coded aperture detector concept is described which enables very high sensitivity studies persistent hard X-ray sources and gamma ray bursts. Coded aperture imaging is employed so that approx. 2 min source locations can be derived within a 3 deg field of view. Gamma bursts were located initially to within approx. 2 deg and X-ray/hard X-ray spectra and timing, as well as precise locations, derived for possible burst afterglow emission. It is suggested that hard X-ray imaging should be conducted from an Explorer mission where long exposure times are possible.

Grindlay, J.E.; Murray, S.S.

1981-11-01T23:59:59.000Z

137

Applications of soft x-ray lasers  

SciTech Connect

The high brightness and short pulse duration of soft x-ray lasers provide unique advantages for novel applications. Imaging of biological specimens using x-ray lasers has been demonstrated by several groups. Other applications to fields such as chemistry, material science, plasma diagnostics, and lithography are beginning to emerge. We review the current status of soft x-ray lasers from the perspective of applications, and present an overview of the applications currently being developed.

Skinner, C.H.

1993-08-01T23:59:59.000Z

138

High speed x-ray beam chopper  

DOE Patents (OSTI)

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.

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

2002-01-01T23:59:59.000Z

139

X-ray laser frequency near-doubling and generation of tunable coherent x rays in plasma  

E-Print Network (OSTI)

X-ray laser frequency near-doubling and generation of tunable coherent x rays in plasma P. L plasmas in which efficient x-ray laser frequency near-doubling is expected for a number of available x-ray of coherent x rays and tunable optical radiation may result in tunable coherent x-ray radiation powerful

Kaplan, Alexander

140

Colloid Coalescence with Focused X Rays  

SciTech Connect

We show direct evidence that focused x rays enable us to merge polymer colloidal particles at room temperature. This phenomenon is ascribed to the photochemical scission of colloids with x rays, reducing the molecular weight, glass transition temperature, surface tension, and viscosity of colloids. The observation of the neck bridge growth with time shows that the x-ray-induced colloid coalescence is analogous to viscoelastic coalescence. This finding suggests a feasible protocol of photonic nanofabrication by sintering or welding of polymers, without thermal damage, using x-ray photonics.

Weon, B. M.; Kim, J. T.; Je, J. H. [X-ray Imaging Center, Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of); Yi, J. M. [Samsung Advanced Institute of Technology, Yongin, Gyeonggi, 446-712 (Korea, Republic of); Wang, S.; Lee, W.-K. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2011-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

X-RAY MICROBEAM SPEECH PRODUCTION DATABASE  

E-Print Network (OSTI)

X-RAY MICROBEAM SPEECH PRODUCTION DATABASE USER'S HANDBOOK Version 1.0 (June 1994) prepared by John . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Chapter Two: XRMB History

142

X-ray laser microscope apparatus  

DOE Patents (OSTI)

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.

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

1990-01-01T23:59:59.000Z

143

Automation in X-Ray Crystallography  

Science Journals Connector (OSTI)

Automation in X-Ray Crystallography ... But in the past few years, automation procedures have been applied to intrinsically superior experimental methods. ...

S.C. ABRAHAMS

1963-06-03T23:59:59.000Z

144

X-Ray Laser Sources for Microscopy  

Science Journals Connector (OSTI)

Progress and prospects in soft X-ray laser development at Princeton are presented. A comparison to plasma and synchrotron sources is made with a...

C. H. Skinner; D. E. Kim; A. Wouters; D. Voorhees; S. Suckewer

1988-01-01T23:59:59.000Z

145

Compound refractive X-ray lens  

DOE Patents (OSTI)

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.

Nygren, David R. (Berkeley, CA); Cahn, Robert (Walnut Creek, CA); Cederstrom, Bjorn (Traellborg, SE); Danielsson, Mats (Stocksund, SE); Vestlund, Jonas (Stockholm, SE)

2000-01-01T23:59:59.000Z

146

X-Ray Science Division (XSD)  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Science Division (XSD) Search Button About Welcome Overview Visiting the APS Mission & Goals Find People Organization Charts Committees Job Openings User Information...

147

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

E-Print Network (OSTI)

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

Krauss, Miriam Ilana

2007-01-01T23:59:59.000Z

148

Ultraluminous X-ray Sources: The most extreme X-ray binaries  

E-Print Network (OSTI)

1 Ultraluminous X-ray Sources: The most extreme X-ray binaries Luca Zampieri INAF ULXs ­ Lubiana ­ May 11, 2012- LZ #12;6 · X-ray observations of nearby galaxies show a population of pointlike, off-nuclear sources with L >> Ledd for 1 Msun (L>1.0e39 erg/s) UltraLuminous X-ray Sources (e

Â?umer, Slobodan

149

X-ray Diffraction (XRD) 1.0 What is X-ray Diffraction  

E-Print Network (OSTI)

X-ray Diffraction (XRD) · 1.0 What is X-ray Diffraction · 2.0 Basics of Crystallography · 3.0 Production of X-rays · 4.0 Applications of XRD · 5.0 Instrumental Sources of Error · 6.0 Conclusions #12 why the cleavage faces of crystals appear to reflect X-ray beams at certain angles of incidence (theta

Moeck, Peter

150

Aneta Siemiginowska Chandra X-ray Center  

E-Print Network (OSTI)

-ray and gamma-ray · High Energy Sky · Chandra X-ray Observatory · examples of typical X-ray data, · an example of a data analysis process · statistical challenges · what do we learn from the data? #12;What is Astronomy and phenomena do we study and how? Solar System: Sun and sollar wind, planets, moons, asteroids, comets Our

Wolfe, Patrick J.

151

Watershed in X-ray Astronomy  

Science Journals Connector (OSTI)

... extent the article on page 96 of this issue of Nature from the X-ray astronomy group at the Massachusetts Institute of Technology is a record of disappointments. That is ... near the galactic centre. Now that the first satellite to be devoted to X-ray astronomy has been launched, and is apparently working successfully, the MIT article and another from ...

1971-01-08T23:59:59.000Z

152

X-Ray Identification of Element 104  

Science Journals Connector (OSTI)

The daughter x-ray identification technique has been applied to the identification of element 104. The characteristic K-series x rays from the ?-decay daughter isotope, nobelium (Z=102), have been observed in coincidence with ? particles from the decay of 4.5-sec 104257, thus providing an unequivocal determination of the parent atomic number, Z=104.

C. E. Bemis; Jr.; R. J. Silva; D. C. Hensley; O. L. Keller; Jr.; J. R. Tarrant; L. D. Hunt; P. F. Dittner; R. L. Hahn; C. D. Goodman

1973-09-03T23:59:59.000Z

153

Quantitative Measurements of X-ray Intensity  

SciTech Connect

This chapter describes the characterization of several X-ray sources and their use in calibrating different types of X-ray cameras at National Security Technologies, LLC (NSTec). The cameras are employed in experimental plasma studies at Lawrence Livermore National Laboratory (LLNL), including the National Ignition Facility (NIF). The sources provide X-rays in the energy range from several hundred eV to 110 keV. The key to this effort is measuring the X-ray beam intensity accurately and traceable to international standards. This is accomplished using photodiodes of several types that are calibrated using radioactive sources and a synchrotron source using methods and materials that are traceable to the U.S. National Institute of Standards and Technology (NIST). The accreditation procedures are described. The chapter begins with an introduction to the fundamental concepts of X-ray physics. The types of X-ray sources that are used for device calibration are described. The next section describes the photodiode types that are used for measuring X-ray intensity: power measuring photodiodes, energy dispersive photodiodes, and cameras comprising photodiodes as pixel elements. Following their description, the methods used to calibrate the primary detectors, the power measuring photodiodes and the energy dispersive photodiodes, as well as the method used to get traceability to international standards are described. The X-ray source beams can then be measured using the primary detectors. The final section then describes the use of the calibrated X-ray beams to calibrate X-ray cameras. Many of the references are web sites that provide databases, explanations of the data and how it was generated, and data calculations for specific cases. Several general reference books related to the major topics are included. Papers expanding some subjects are cited.

Haugh, M. J., Schneider, M.

2011-09-01T23:59:59.000Z

154

X-ray Practicals Series 1 Advanced Data Reduction  

E-Print Network (OSTI)

X-ray Practicals Series 1 Advanced Data Reduction Instructor J. Reibenspies, Ph. D. Nattamai Bhuvanesh, Ph.D. Version 1.0.0 #12;X-ray Practicals Series 2 #12;X-ray Practicals Series 3 #12;X-ray is good. The y direction is shifting the most, but the shift is ok #12;X-ray Practicals Series 5 Other

Meagher, Mary

155

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless X-Ray Imaging in 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 important for coherent x-ray diffraction imaging-lensless imaging techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

156

X-ray sources in globular clusters  

E-Print Network (OSTI)

The twelve bright (Lx>10(36) erg/s) X-ray sources in the globular clusters have lower luminosities than the brightest sources in the bulge of our galaxy. The dim (Lx<10(35) erg/s) X-ray sources in globular clusters reach higher luminosities than the cataclysmic variables in the disk of our galaxy. The first difference is a statistical fluke, as comparison with M31 indicates. The second difference is explained because the brightest of the dim sources are not cataclysmic variables, but soft X-ray transients in quiescence. This article describes the BeppoSAX, ROSAT and first Chandra observations leading to these conclusions.

Frank Verbunt

2001-11-22T23:59:59.000Z

157

X-RAY EMISSION FROM PLANETS AND COMETS: RELATIONSHIP WITH SOLAR X-RAYS AND SOLAR WIND  

E-Print Network (OSTI)

with the occurrence of solar X-ray flare, when light travel time delay is accounted, suggesting that X-rays fromX-RAY EMISSION FROM PLANETS AND COMETS: RELATIONSHIP WITH SOLAR X-RAYS AND SOLAR WIND ANIL BHARDWAJ Flight center, Greenbelt, MD 20771, USA Scattering of solar X-ray radiation mainly produces the non

Ã?stgaard, Nikolai

158

X-Ray Diffraction The X-Ray Diffraction facility is equipped with state-of-the-art  

E-Print Network (OSTI)

X-Ray Diffraction The X-Ray Diffraction facility is equipped with state-of-the-art diffractometers offering both single crystal and powder X-Ray diffraction. Powder X-Ray Diffraction High resolution data For more details on powder X-Ray analysis contact Dr J Hriljac on 0121 414 4458 or email: j

Birmingham, University of

159

Novel X-Ray Imaging Opportunities for the RPI Linear Accelerator's Tunable, Quasi-monochromatic X-ray Source  

E-Print Network (OSTI)

Novel X-Ray Imaging Opportunities for the RPI Linear Accelerator's Tunable, Quasi-monochromatic X-ray of an intense, tunable, polarized, and quasi-monochromatic X-ray source has been ongoing at Rensselaer Polytechnic Institute since 2001 [1, 2, 3, 4, 5, 6]. This X-ray source, known as Parametric X-rays (PXR

Danon, Yaron

160

X-ray Absorption Spectroscopy of Biologically Relevant Systems  

E-Print Network (OSTI)

308, Messer, B. M. X-ray Absorption Spectroscopy of AqueousSarcosine via X-ray Absorption Spectroscopy 5.1 Introductionwith Carboxylate by X-Ray Absorption Spectroscopy of Liquid

Uejio, Janel Sunayo

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Compact X-Ray Light Source Workshop | EMSL  

NLE Websites -- All DOE Office Websites (Extended Search)

Compact X-Ray Light Source Workshop Compact X-Ray Light Source Workshop Teller R, Terminello L, Thevuthasan T, Moncton D. 2012. "Compact X-Ray Light Source Workshop Report."...

162

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (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...

163

Nanoscale chemical imaging using synchrotron x-ray enhanced scanning tunneling microscopy  

SciTech Connect

The combination of synchrotron radiation with scanning tunneling microscopy provides a promising new concept for chemical imaging of nanoscale structures. It employs detection of local x-ray absorption, which directly yields chemical, electronic, and magnetic sensitivity. The study of the tip current in the far field (800 nm tip/sample separation) shows that insulator-coated tips have to be considered in order to reduce the background from stray photoelectron. A picture of the different channels contributing to the x-ray enhanced STM process is proposed. If during electron tunneling the sample is illuminated with monochromatic x-rays, characteristic absorption will arise, and core electrons are excited, which might modulate the conventional tunnel current and facilitate chemical imaging at the nanoscale.

Rose, Volker; Freeland, John W. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2010-06-23T23:59:59.000Z

164

APS Bending Magnet X-rays and  

NLE Websites -- All DOE Office Websites (Extended Search)

Irradiation of Nd-Fe-B Permanent Magnets with Irradiation of Nd-Fe-B Permanent Magnets with APS Bending Magnet X-rays and 60 Co γ-rays J. Alderman and P.K. Job APS Operations Division Advanced Photon Source J. Puhl Ionizing Radiation Division National Institute of Standards and Technology June 2000 Table of Contents Introduction Radiation-Induced Demagnetization of Permanent Magnets Resources Required γ-ray Irradiation Results and Analysis of γ-ray Irradiation X-ray Irradiation Results and Analysis of X-ray Irradiation Summary and Conclusions Acknowledgements References Tables and Figures Introduction The Advanced Photon Source (APS), as well as other third-generation synchrotron light sources, uses permanent magnets in the insertion devices to produce x-rays for scientific

165

X-ray source for mammography  

DOE Patents (OSTI)

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.

Logan, Clinton M. (Pleasanton, CA)

1994-01-01T23:59:59.000Z

166

Ultrafast X-Ray Sources and Science  

Science Journals Connector (OSTI)

X-ray science is entering the ultrafast and ultraintense era - spurred by developments in coherent, short-wavelength sources that range from tabletop to accelerator-based. These...

Young, Linda

167

SMB, X-ray Emission Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Emission Spectroscopy Beam Line 6-2b X-ray Emission Spectroscopy Beam Line 6-2b is an advanced spectroscopy experimental station on the multidisciplinary general user wiggler Beam...

168

X-raying galaxies: A Chandra legacy  

Science Journals Connector (OSTI)

...Astronomy, University of Massachusetts, Amherst, MA 01003 This presentation...stellar x-ray sources in the solar neighborhood (8). The...elements—Meteoritic and solar . Geochim Cosmochim Acta 53...Astronomy, University of Massachusetts, Amherst, MA 01003, USA...

Q. Daniel Wang

2010-01-01T23:59:59.000Z

169

Small Angle X-Ray Scattering Detector  

DOE Patents (OSTI)

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.

Hessler, Jan P.

2004-06-15T23:59:59.000Z

170

X-Ray Nanoimaging: Instruments and Methods  

NLE Websites -- All DOE Office Websites (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...

171

Femtosecond X-ray protein nanocrystallography  

NLE Websites -- All DOE Office Websites (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.,...

172

X-ray source for mammography  

DOE Patents (OSTI)

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.

Logan, C.M.

1994-12-20T23:59:59.000Z

173

Using X-Ray Computed Tomography in Pore Structure Characterization...  

NLE Websites -- All DOE Office Websites (Extended Search)

Using X-Ray Computed Tomography in Pore Structure Characterization for a Berea Sandstone: Resolution Effect. Using X-Ray Computed Tomography in Pore Structure Characterization for...

174

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging in Reflection Print 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 are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

175

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging in Reflection Print 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 are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

176

Argonne CNM: X-Ray Microscopy Capabilities  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Microscopy Facilities X-Ray Microscopy Facilities The Hard X-Ray Nanoprobe (HXN) facility provides scanning fluorescence, scanning diffraction, and full-field transmission and tomographic imaging capabilities with a spatial resolution of 30 nm over a spectral range of 6-12 keV. Modes of Operation Full-Field Transmission Imaging and Nanotomography X-ray transmission imaging uses both the absorption and phase shift of the X-ray beam by the sample as contrast mechanisms. Absorption contrast is used to map the sample density. Elemental constituents can be located by using differential edge contrast in this mode. Phase contrast can be highly sensitive to edges and interfaces even when the X-ray absorption is weak. These contrast mechanisms are exploited to image samples rapidly in full-field transmission mode under various environmental conditions, or combined with nanotomography methods to study the three-dimensional structure of complex and amorphous nanomaterials with the HXN.

177

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless X-Ray Imaging in Reflection Print 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 techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

178

The Constellation X-ray mission  

Science Journals Connector (OSTI)

The Constellation-X mission is a large collecting area X-ray facility, emphasizing observations at high spectral resolution (E/?E?300–3000) while covering a broad energy band (0.25–40 keV). By increasing the telescope aperture and utilizing efficient spectrometers the mission will achieve a factor of 100 increased sensitivity over current high-resolution X-ray spectroscopy missions. The use of focussing optics across the 10–40 keV band will provide a similar factor of 100 increased sensitivity in this band. Key technologies under development for the mission include lightweight high throughput X-ray optics, multilayer coatings to enhance the hard X-ray performance of X-ray optics, micro-calorimeter spectrometer arrays with 2 eV resolution, low-power and low-weight CCD arrays, lightweight gratings and hard X-ray detectors. When observations commence towards the end of the next decade, Constellation-X will address many pressing questions concerning the extremes of gravity and the evolution of the Universe.

N.E White; H Tananbaum

1999-01-01T23:59:59.000Z

179

X-Ray Observations of Radio Galaxies  

E-Print Network (OSTI)

We review some of the ways that X-ray observations provide unique information on radio galaxies. Thermal bremsstrahlung X-ray emission provides detailed data on ambient densities and temperatures. These parameters in turn can be used for pressure balance calculations and can demonstrate how the ambient gas affects radio source structure. Additionally, many signatures of the interaction of radio jets and lobes with the hot gas are found in high resolution X-ray maps. Non-thermal X-ray emission from knots and hotspots of radio jets can give us constraints on the relativistic electron population for energies greater that that normally sampled in the radio (in the case of synchrotron emission) or can give us an independent estimate of the average magnetic field strength (if inverse Compton emission is the origin of the X-rays). From recent ROSAT HRI observations of 3C 390.3 and 3C 120, we show evidence that X-ray emission from knots and hotspots appears to be associated with regions of large gradients in the radio surface brightness; i.e. at the location of powerful shocks.

D. E. Harris

1998-04-20T23:59:59.000Z

180

Compton backscattered collimated x-ray source  

DOE Patents (OSTI)

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.

Ruth, R.D.; Huang, Z.

1998-10-20T23:59:59.000Z

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Compton backscattered collmated X-ray source  

DOE Patents (OSTI)

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.

Ruth, Ronald D. (Woodside, CA); Huang, Zhirong (Stanford, CA)

2000-01-01T23:59:59.000Z

182

Compton backscattered collimated x-ray source  

DOE Patents (OSTI)

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.

Ruth, Ronald D. (Woodside, CA); Huang, Zhirong (Stanford, CA)

1998-01-01T23:59:59.000Z

183

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless X-Ray Imaging in Reflection Print 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 techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

184

Development of x-ray laminography under an x-ray microscopic condition  

SciTech Connect

An x-ray laminography system under an x-ray microscopic condition was developed to obtain a three-dimensional structure of laterally-extended planar objects which were difficult to observe by x-ray tomography. An x-ray laminography technique was introduced to an x-ray transmission microscope with zone plate optics. Three prototype sample holders were evaluated for x-ray imaging laminography. Layered copper grid sheets were imaged as a laminated sample. Diatomite powder on a silicon nitride membrane was measured to confirm the applicability of this method to non-planar micro-specimens placed on the membrane. The three-dimensional information of diatom shells on the membrane was obtained at a spatial resolution of sub-micron. Images of biological cells on the membrane were also obtained by using a Zernike phase contrast technique.

Hoshino, Masato; Uesugi, Kentaro; Takeuchi, Akihisa; Suzuki, Yoshio; Yagi, Naoto [Japan Synchrotron Radiation Research Institute JASRI/SPring-8, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)

2011-07-15T23:59:59.000Z

185

X-ray views of neutron star low-mass X-ray binaries  

E-Print Network (OSTI)

A neutron star low-mass X-ray binary is a binary stellar system with a neutron star and a low-mass companion star rotating around each other. In this system the neutron star accretes mass from the companion, and as this matter falls into the deep potential well of the neutron star, the gravitational potential energy is released primarily in the X-ray wavelengths. Such a source was first discovered in X-rays in 1962, and this discovery formally gave birth to the "X-ray astronomy". In the subsequent decades, our knowledge of these sources has increased enormously by the observations with several X-ray space missions. Here we give a brief overview of our current understanding of the X-ray observational aspects of these systems.

Sudip Bhattacharyya

2010-02-24T23:59:59.000Z

186

Is linear response to x-rays suitable for digital dental x-ray imaging systems? —Theoretical and experimental considerations  

Science Journals Connector (OSTI)

The purpose of this study was to consider theoretically and experimentally the suitability of linear response to x-rays for digital dental x-ray imaging systems.

Keiichi Nishikawa PhD; Mamoru Wakoh DDS; PhD; Kinya Kuroyanagi DDS; PhD

2003-06-01T23:59:59.000Z

187

Ambient-Pressure Bulk Superconductivity Deep in the Magnetic State of CeRhIn5  

SciTech Connect

Specific heat, magnetic susceptibility and electrical transport measurements were performed at ambient pressure on high-quality single crystal specimens of CeRhIn5 down to ultra-low temperatures. We report signatures of an anomaly observed in all measured quantities consistent with a bulk phase transition to a superconducting state at T{sub c}=110 mK. Occurring far below the onset of antiferromagnetism at T{sub N}=3.8 K, this transition appears to involve a significant portion of the available low-temperature density of electronic states, exhibiting an entropy change in line with that found in other members of the 115 family of superconductors tuned away from quantum criticality.

Paglione,J.; Ho, P.; Maple, M.; Tanatar, M.; Taillefer, L.; Lee, Y.; Petrovic, C.

2008-01-01T23:59:59.000Z

188

Wet etching of GaAs using synchrotron radiation x rays  

Science Journals Connector (OSTI)

The results of room-temperature wet etching of GaAs using synchrotron-radiation x rays are described. Under x-rayillumination etching occurs on the n- GaAs surface in contact with an acid or base solution or even deionized water. The etching process is studied as functions of the electrolytes their concentration semiconductor doping level and x-ray intensity and energy. The etching mechanism is determined to be primarily electrochemical in nature but the x-ray radiation chemistry plays a role in the etching. Smoothly etchedsurfaces are achievable with a root-mean-square surface roughness of 0.7–2.0 nm. We also found that the etching rate increases substantially with the ratio of the sample size to the x-ray exposure size. This is accounted for by the rate-limiting effect on the charge transfer across the semiconductor-electrolyte junction. The chemistry of etchedsurfaces is studied using x-ray photoelectron spectroscopy and compared to that of as-received surfaces.

Qing Ma; Nicolaie Moldovan; Derrick C. Mancini; Richard A. Rosenberg

2001-01-01T23:59:59.000Z

189

X-ray Pinhole Camera Measurements  

SciTech Connect

The development of the rod pinch diode [1] has led to high-resolution radiography for dynamic events such as explosive tests. Rod pinch diodes use a small diameter anode rod, which extends through the aperture of a cathode plate. Electrons borne off the aperture surface can self-insulate and pinch onto the tip of the rod, creating an intense, small x-ray source (Primary Pinch). This source has been utilized as the main diagnostic on numerous experiments that include high-value, single-shot events. In such applications there is an emphasis on machine reliability, x-ray reproducibility, and x-ray quality [2]. In tests with the baseline rod pinch diode, we have observed that an additional pinch (Secondary Pinch) occurs at the interface near the anode rod and the rod holder. This suggests that stray electrons exist that are not associated with the Primary Pinch. In this paper we present measurements on both pinches using an x-ray pinhole camera. The camera is placed downstream of the Primary Pinch at an angle of 60° with respect to the diode centerline. This diagnostic will be employed to diagnose x-ray reproducibility and quality. In addition, we will investigate the performance of hybrid diodes relating to the formation of the Primary and Secondary Pinches.

Nelson, D. S. [NSTec; Berninger, M. J. [NSTec; Flores, P. A. [NSTec; Good, D. E. [NSTec; Henderson, D. J. [NSTec; Hogge, K. W. [NSTec; Huber, S. R. [NSTec; Lutz, S. S. [NSTec; Mitchell, S. E. [NSTec; Howe, R. A. [NSTec; Mitton, C. V. [NSTec; Molina, I. [NSTec; Bozman, D. R. [SNL; Cordova, S. R. [SNL; Mitchell, D. R. [SNL; Oliver, B. V. [SNL; Ormond, E. C. [SNL

2013-07-01T23:59:59.000Z

190

Nonlinear X-ray Compton Scattering  

E-Print Network (OSTI)

X-ray scattering is a weak linear probe of matter. It is primarily sensitive to the position of electrons and their momentum distribution. Elastic X-ray scattering forms the basis of atomic structural determination while inelastic Compton scattering is often used as a spectroscopic probe of both single-particle excitations and collective modes. X-ray free-electron lasers (XFELs) are unique tools for studying matter on its natural time and length scales due to their bright and coherent ultrashort pulses. However, in the focus of an XFEL the assumption of a weak linear probe breaks down, and nonlinear light-matter interactions can become ubiquitous. The field can be sufficiently high that even non-resonant multiphoton interactions at hard X-rays wavelengths become relevant. Here we report the observation of one of the most fundamental nonlinear X-ray-matter interactions, the simultaneous Compton scattering of two identical photons producing a single photon at nearly twice the photon energy. We measure scattered...

Fuchs, Matthias; Chen, Jian; Ghimire, Shambhu; Shwartz, Sharon; Kozina, Michael; Jiang, Mason; Henighan, Thomas; Bray, Crystal; Ndabashimiye, Georges; Bucksbaum, P H; Feng, Yiping; Herrmann, Sven; Carini, Gabriella; Pines, Jack; Hart, Philip; Kenney, Christopher; Guillet, Serge; Boutet, Sebastien; Williams, Garth; Messerschmidt, Marc; Seibert, Marvin; Moeller, Stefan; Hastings, Jerome B; Reis, David A

2015-01-01T23:59:59.000Z

191

X-ray lithography using holographic images  

DOE Patents (OSTI)

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.

Howells, M.S.; Jacobsen, C.

1997-03-18T23:59:59.000Z

192

Oscillations During Thermonuclear X-ray Bursts  

E-Print Network (OSTI)

High amplitude, nearly coherent X-ray brightness oscillations during thermonuclear X-ray bursts were discovered with the Rossi X-ray Timing Explorer (RXTE) in early 1996. Spectral and timing evidence strongly supports the conclusion that these oscillations are caused by rotational modulation of the burst emission and that they reveal the spin frequency of neutron stars in low mass X-ray binaries, a long sought goal of X-ray astronomy. Studies carried out over the past year have led to the discovery of burst oscillations in four new sources, bringing to ten the number with confirmed burst oscillations. I review the status of our knowledge of these oscillations and indicate how they can be used to probe the physics of neutron stars. For a few burst oscillation sources it has been proposed that the strongest and most ubiquitous frequency is actually the first overtone of the spin frequency and hence that two nearly antipodal hot spots are present on the neutron star. This inference has important implications for both the physics of thermonuclear burning as well as the mass - radius relation for neutron stars, so its confirmation is crucial. I discuss recent attempts to confirm this hypothesis for 4U 1636-53, the source for which a signal at the putative fundamental (290 Hz) has been claimed.

Tod E. Strohmayer

2001-01-12T23:59:59.000Z

193

X-ray lithography using holographic images  

DOE Patents (OSTI)

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.

Howells, Malcolm S. (Berkeley, CA); Jacobsen, Chris (Sound Beach, NY)

1997-01-01T23:59:59.000Z

194

Predicted X-ray backgrounds for the International X-ray Observatory  

E-Print Network (OSTI)

The background that will be observed by IXO's X-ray detectors naturally separates into two components: (1) a Cosmic X-ray Background (CXB), primarily due to unresolved point sources at high energies (E>2 keV), along with ...

Bautz, Marshall W.

195

Reflection soft X-ray microscope and method  

DOE Patents (OSTI)

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.

Suckewer, Szymon (Princeton, NJ); Skinner, Charles H. (Lawrenceville, NJ); Rosser, Roy (Princeton, NJ)

1993-01-01T23:59:59.000Z

196

Differential phase contrast X-ray imaging system and components  

DOE Patents (OSTI)

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.

Stutman, Daniel; Finkenthal, Michael

2014-07-01T23:59:59.000Z

197

X-ray variability in M87  

E-Print Network (OSTI)

We present the evidence for X-ray variability from the core and from knot A in the M87 jet based on data from two observations with the Einstein Observatory High Resolution Imager (HRI) and three observations with the ROSAT HRI. The core intensity showed a 16% increase in 17 months ('79-'80); a 12% increase in the 3 years '92 to '95; and a 17% drop in the last half of 1995. The intensity of knot A appears to have decreased by 16% between 92Jun and 95Dec. Although the core variability is consistent with general expectations for AGN nuclei, the changes in knot A provide constraints on the x-ray emission process and geometry. Thus we predict that the x-ray morphology of knot A will differ significantly from the radio and optical structure.

D. E. Harris; J. A. Biretta; W. Junor

1996-12-05T23:59:59.000Z

198

Displaced Vertices from X-ray Lines  

E-Print Network (OSTI)

We present a simple model of weak-scale thermal dark matter that gives rise to X-ray lines. Dark matter consists of two nearly degenerate states near the weak scale, which are populated thermally in the early universe via co-annihilation with slightly heavier states that are charged under the Standard Model. The X-ray line arises from the decay of the heavier dark matter component into the lighter one via a radiative dipole transition, at a rate that is slow compared to the age of the universe. The model predicts observable signatures at the LHC in the form of exotic events with missing energy and displaced leptons and jets. As an application, we show how this model can explain the recently observed 3.55 keV X-ray line.

Adam Falkowski; Yonit Hochberg; Joshua T. Ruderman

2014-09-09T23:59:59.000Z

199

X-ray focal spot locating apparatus and method  

DOE Patents (OSTI)

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.

Gilbert, Hubert W. (Cedar Crest, NM)

1985-07-30T23:59:59.000Z

200

X-ray Science Division: Groups  

NLE Websites -- All DOE Office Websites (Extended Search)

Division: Groups Division: Groups Atomic, Molecular and Optical Physics (AMO) Primary Contact: Stephen Southworth Work focuses on understanding how strong optical and x-ray fields interact with matter, with an emphasis on photonic control of electronic, atomic and molecular motion. Chemical and Materials Science (CMS) Primary Contact: Randy Winans Research Disciplines: Chemistry, Materials Science Detectors (DET) Primary Contact: Antonino Miceli GMCA Structural Biology Facility (MX) Primary Contact: Robert Fischetti Research Disciplines: Biology, Life Sciences Imaging (IMG) Primary Contact: Francesco DeCarlo Research Disciplines: Materials Science, Biology, Physics, Life Sciences Inelastic X-ray & Nuclear Resonant Scattering (IXN) Primary Contact: Thomas Gog Research Disciplines: Condensed Matter Physics, Geophysics, Materials

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Cosmology with X-ray Cluster Baryons  

SciTech Connect

X-ray cluster measurements interpreted with a universal baryon/gas mass fraction can theoretically serve as a cosmological distance probe. We examine issues of cosmological sensitivity for current (e.g., Chandra X-ray Observatory, XMM-Newton) and next generation (e.g., Con-X, XEUS) observations, along with systematic uncertainties and biases. To give competitive next generation constraints on dark energy, we find that systematics will need to be controlled to better than 1percent and any evolution in f_gas (and other cluster gas properties) must be calibrated so the residual uncertainty is weaker than (1+z)0.03.

Linder, Eric V.

2007-04-10T23:59:59.000Z

202

Phase recovery for x-ray crystallography  

Science Journals Connector (OSTI)

For many years people have believed that in conventional x-ray crystallography one can only record the diffraction intensities but not the phases. In order to obtain the atomic arrangements, one usually has to guess a structure and then fit the intensity data by refining its parameters. Here, we show that the phases are in fact hidden in the intensity data, and can be directly recovered from the peak profiles. This method is demonstrated by the normal two-beam x-ray diffraction of a noncentrosymmetric crystal, and nontrivial phases are recovered from the intensity data alone.

G. Xu, G. E. Zhou, and X. Y. Zhang

1999-04-01T23:59:59.000Z

203

Time-resolved x-ray diagnostics  

SciTech Connect

Techniques for time-resolved x-ray diagnostics will be reviewed with emphasis on systems utilizing x-ray diodes or scintillators. System design concerns for high-bandwidth (> 1 GHz) diagnostics will be emphasized. The limitations of a coaxial cable system and a technique for equalizing to improve bandwidth of such a system will be reviewed. Characteristics of new multi-GHz amplifiers will be presented. An example of a complete operational system on the Los Alamos Helios laser will be presented which has a bandwidth near 3 GHz over 38 m of coax. The system includes the cable, an amplifier, an oscilloscope, and a digital camera readout.

Lyons, P.B.

1981-01-01T23:59:59.000Z

204

Superconductivity at 93 K in a new mixed-phase Y-Ba-Cu-O compound system at ambient pressure  

Science Journals Connector (OSTI)

A stable and reproducible superconductivity transition between 80 and 93 K has been unambiguously observed both resistively and magnetically in a new Y-Ba-Cu-O compound system at ambient pressure. An estimated upper critical field Hc2(0) between 80 and 180 T was obtained.

M. K. Wu; J. R. Ashburn; C. J. Torng; P. H. Hor; R. L. Meng; L. Gao; Z. J. Huang; Y. Q. Wang; C. W. Chu

1987-03-02T23:59:59.000Z

205

Sharper Focusing of Hard X-rays  

NLE Websites -- All DOE Office Websites (Extended Search)

Sharper Focusing of Hard X-rays FROM: Physics News Update Number 773 #1, April 12, 2006, by Phil Schewe and Ben Stein Note: This text has been slightly modified from the original. Sharper focusing of hard x-rays has been achieved with a device developed at Argonne National Lab. Because of their high energy, x-rays are hard to focus: they can be reflected from a surface but only at a glancing angle (less than a tenth of a degree); they can be refracted but the index of refraction is very close to 1, so that making efficient lenses becomes a problem; and they can be diffracted, but the relatively thick, variable pitch grating required for focusing is tricky to achieve. The Argonne device is of the diffraction type, and it consists of a stack of alternating layers of metal and silicon, made by depositing progressively thicker layers. When the x-rays fall on such a structure, nearly edge-on, what they see is a grating (called a linear zone plate) consisting of a sort of bar-code pattern.

206

Radioactive Thulium for X-Rays  

Science Journals Connector (OSTI)

Radioactive power from thulium makes Argonne x-ray unit a potential for medical and industrial use ... Active component of the instrument is a tiny particle (one-fifth gram) of thulium-170 which has been made radioactive in a heavy water nuclear reactor at Arco, Idaho. ...

1954-05-03T23:59:59.000Z

207

X-ray spectroscopy of manganese clusters  

SciTech Connect

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.

Grush, M.M. [Univ. of California, Davis, CA (United States). Dept. of Applied Science; [Lawrence Berkeley National Lab., CA (United States). Energy and Environment Div.

1996-06-01T23:59:59.000Z

208

Multiple wavelength X-ray monochromators  

DOE Patents (OSTI)

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.

Steinmeyer, P.A.

1992-11-17T23:59:59.000Z

209

Soft x-ray laser microscope  

SciTech Connect

The program consisted of two phases (Phase I and Phase II). The goal of the Phase I (first year program) was to design and construct the Soft X-ray Laser Contact Microscope. Such microscope was constructed and adapted to PPL's 18.2nm soft X-ray Laser (SXL), which in turn was modified and prepared for microscopy experiments. Investigation of the photoresist response to 18.2nm laser radiation and transmissivity of 0.1m thick silicion-nitride (Si[sub 3]N[sub 4]) windows were important initial works. The goal of the first year of Phase II was to construct X-ray contact microscope in combination with existing optical phase microscope, already used by biologists. In the second year of Phase II study of dehydrated Horeseshoe Crab and Hela cancer cells were performed with COXRALM. Also during Phase II, the Imaging X-Ray Laser Microscope (IXRALM) was designed and constructed. This paper describes the development of each of the microscopes and their application for research.

Suckewer, P.I.

1990-10-01T23:59:59.000Z

210

Small Angle X-Ray Scattering Detector  

DOE Patents (OSTI)

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.

Hessler, Jan P. (Downers Grove, IL)

2004-06-15T23:59:59.000Z

211

SLAC All Access: X-ray Microscope  

ScienceCinema (OSTI)

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.

Nelson, Johanna; Liu, Yijin

2014-06-13T23:59:59.000Z

212

A hybrid Rankine cycle (HyRC) with ambient pressure combustion (APC)  

Science Journals Connector (OSTI)

Abstract The main losses in thermal power generation include heat in exhaust flue gas, heat rejected through steam condensation of low-pressure turbine, and exergy destruction in heat exchange process etc. To the extent that the heat losses are significantly greater in temperature than either air or water coolant resources, these losses also represent exergy losses which might be exploited to improve plant capacity and efficiency. This paper presents a hybrid Rankine cycle (HyRC) with an ambient pressure combustion (APC) boiler to address the recovery potential of these losses within the steam Rankine cycle (SRC). The APC–HyRC concept employs an organic Rankine cycle (ORC) to supplement SRC and to reduce cycle energy losses to the atmosphere since organic fluids are capable of lowering cycle condensation temperature when a very low temperature heat sink is available. The case studies based on a 399 MW SRC unit show that the APC–HyRC configurations have better thermodynamic performance than its base case SRC at a cycle condensation temperature of 30 °C and below. The best APC–HyRC configuration generates up to 14% more power than the baseline steam cycle which is a 5.45% increase in overall gross efficiency with a cycle condensation temperature at 4 °C.

Lijun Wu; David Thimsen; Bruce Clements; Ligang Zheng; Richard Pomalis

2014-01-01T23:59:59.000Z

213

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

SciTech Connect

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

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

1984-01-01T23:59:59.000Z

214

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

DOE Patents (OSTI)

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.

Bitter, Manfred L. (Princeton, NJ); Fraenkel, Ben (Jerusalem, IL); Gorman, James L. (Bordentown, NJ); Hill, Kenneth W. (Lawrenceville, NJ); Roquemore, A. Lane (Cranbury, NJ); Stodiek, Wolfgang (Princeton, NJ); von Goeler, Schweickhard E. (Princeton, NJ)

2001-01-01T23:59:59.000Z

215

Rise Time Measurement for Ultrafast X-Ray Pulses  

DOE Patents (OSTI)

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.

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

2005-04-05T23:59:59.000Z

216

X-ray microscopy using grazing-incidence reflection optics  

SciTech Connect

The Kirkpatrick-Baez microscopes are described along with their role as the workhorse of the x-ray imaging devices. This role is being extended with the development of a 22X magnification Kirkpatrick-Baez x-ray microscope with multilayer x-ray mirrors. These mirrors can operate at large angles, high x-ray energies, and have a narrow, well defined x-ray energy bandpass. This will make them useful for numerous experiments. However, where a large solid angle is needed, the Woelter microscope will still be necessary and the technology needed to build them will be useful for many other types of x-ray optics.

Price, R.H.

1981-08-06T23:59:59.000Z

217

X-RAY POINT-SOURCE POPULATIONS CONSTITUTING THE GALACTIC RIDGE X-RAY EMISSION  

SciTech Connect

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.

Morihana, Kumiko [Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)] [Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Tsujimoto, Masahiro; Ebisawa, Ken [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, 3-1-1 Yoshino-dai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)] [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, 3-1-1 Yoshino-dai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Yoshida, Tessei, E-mail: morihana@crab.riken.jp [National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo 181-8588 (Japan)] [National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo 181-8588 (Japan)

2013-03-20T23:59:59.000Z

218

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

SciTech Connect

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

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

2009-04-02T23:59:59.000Z

219

X-rays Illuminate Ancient Archimedes Text  

NLE Websites -- All DOE Office Websites (Extended Search)

Related Links: 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 Mechanical Theorems, one of Archimedes' most important works, which was probably copied out by a scribe in the tenth century. The parchment on which it was written was later scraped down and reused as pages in a twelfth century prayer book, producing a document known as a palimpsest (which comes from the Greek,

220

HIGH BRILLIANCE X-RAY SCATTERING FOR  

NLE Websites -- All DOE Office Websites (Extended Search)

BRILLIANCE X-RAY SCATTERING FOR BRILLIANCE X-RAY SCATTERING FOR LIFE SCIENCES (LIX) Group Leader: Lin Yang Proposal Team: O. Bilsel 1 , B. Hsiao 2 , H. Huang 3 , T. Irving 4 , A. Menzel 5 , L. Pollack 6 , C. Riekel 7 , J. Rubert 8 , H. Tsuruta 9 , L. Yang 10 1 University of Massachusetts, 2 Stony Brook University, 3 Rice University, 4 IIT, 5SLS, 6 Cornell University, 7 European Synchrotron Radiation Facility, 8 NEU, 9 Stanford Synchrotron Radiation Lightsource, 10 Brookhaven National Laboratory TECHNIQUES AND CAPABILITIES APPLICATIONS ADDITIONAL INFORMATION * Energy range 2-20keV using undulator source. Simultaneous SAXS/WAXS to cover 0.003-3Å -1 at 12keV with 1 micron spot size * Time-resolved solution scattering with resolution of (1) microseconds to milliseconds using continuous-flow mixing (5µm x 10µm spot size) and (2) milliseconds using stopped-

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221

Element 104 identified by characteristic x rays  

Science Journals Connector (OSTI)

A research team at the Oak Ridge National Laboratory has recently announced that they have conclusively identified the 257 isotope of element 104. This new work shows promise of shedding light on the controversy between Albert Ghiorso and Georgi N. Flerov the leaders respectively of the groups at Lawrence Berkeley Laboratory and the Joint Institute for Nuclear Research Dubna. The isotope 104 X 257 decays by alpha emission to 102 No 253 with a half?life of 4.3 seconds. The Oak Ridge group observed the K?series x rays from nobelium in coincidence with the alpha particles from 104 X 257 ; the observation of x?ray spectra has never been reported previously by the Berkeley or Dubna workers according to Curtis E. Bemis Jr spokesman for the group.

Ronald J. Cohn

1973-01-01T23:59:59.000Z

222

X-ray radiography for container inspection  

DOE Patents (OSTI)

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.

Katz, Jonathan I. (Clayton, MO); Morris, Christopher L. (Los Alamos, NM)

2011-06-07T23:59:59.000Z

223

Sample holder for X-ray diffractometry  

DOE Patents (OSTI)

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.

Hesch, Victor L. (Los Alamos, NM)

1992-01-01T23:59:59.000Z

224

Columbia University X-Ray Measurements  

E-Print Network (OSTI)

V-720 keV · NaI 2x2x2" detector views an energy range of 1 keV-3 MeV Store signal in the tree. computer configuration. Plasmas were created using multi-frequency ECRH, and we find that most of the plasma energy is stored in the fast electrons. The energy spectrum of the x-ray emission below 740 keV is measured

225

Silicon Absolute X-Ray Detectors  

SciTech Connect

The responsivity of silicon photodiodes having no loss in the entrance window, measured using synchrotron radiation in the 1.75 to 60 keV range, was compared to the responsivity calculated using the silicon thickness measured using near-infrared light. The measured and calculated responsivities agree with an average difference of 1.3%. This enables their use as absolute x-ray detectors.

Seely, John F. [Naval Research Laboratory, Washington, D.C. 20375 (United States); Korde, Raj; Sprunck, Jacob [International Radiation Detectors, Inc., Torrance, CA 90505-5243 (United States); Medjoubi, Kadda; Hustache, Stephanie [Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette CEDEX (France)

2010-06-23T23:59:59.000Z

226

Ultrashort x-ray backlighters and applications  

SciTech Connect

Previously, using ultrashort laser pulses focused onto solid targets, we have experimentally studied a controllable ultrafast broadband radiation source in the extreme ultraviolet for time-resolved dynamical studies in ultrafast science [J. Workman, A. Maksimchuk, X. Llu, U. Ellenberger, J. S. Coe, C.-Y. Chien, and D. Umstadter, ``Control of Bright Picosecond X-Ray Emission from Intense Sub- Picosecond Laser-Plasma Interactions,`` Phys. Rev. Lett. 75, 2324 (1995)]. Once armed with a bright ultrafast broadband continuum x-ray source and appropriate detectors, we used the source as a backlighter to study a remotely produced plasma. The application of the source to a problem relevant to high-density matter completes the triad: creating and controlling, efficiently detecting, and applying the source. This work represented the first use of an ultrafast laser- produced x-ray source as a time-resolving probe in an application relevant to atomic, plasma and high-energy-density matter physics. Using the x-ray source as a backlighter, we adopted a pump-probe geometry to investigate the dynamic changes in electronic structure of a thin metallic film as it is perturbed by an ultrashort laser pulse. Because the laser deposits its energy in a skin depth of about 100 {Angstrom} before expansion occurs, up to gigabar pressure shock waves lasting picosecond in duration have been predicted to form in these novel plasmas. This raises the possibility of studying high- energy-density matter relevant to inertial confinement fusion (ICF) and astrophysics in small-scale laboratory experiments. In the past, time-resolved measurements of K-edge shifts in plasmas driven by nanosecond pulses have been used to infer conditions in highly compressed materials. In this study, we used 100-fs laser pulses to impulsively drive shocks into a sample (an untamped 1000 {Angstrom} aluminum film on 2000 {Angstrom} of parylene-n), measuring L-edge shifts.

Umstadter, D., University of Michigan

1997-08-01T23:59:59.000Z

227

X-ray holography at Lawrence Livermore National Laboratory  

SciTech Connect

The x-ray holography program at the Lawrence Livermore National Laboratory has two principal goals: (1) the development of x-ray diffraction techniques for DNA sequence analysis and (2) the development of x-ray laser holography for structural analysis of intact biological cells and organelles. DNA sequence analysis will be accomplished by applying x-ray diffraction techniques to determine the ensemble average of the sequence of labels along the individual elements of crystalline DNA. X-ray laser holographic imaging will be accomplished by applying three dimensional x-ray holography to elucidate the structure of few hundred angstrom objects such as 300 {Angstrom} chromatin fibers, nuclear pores and nucleic acid replication complexes in living cells. Existing laboratory x-ray lasers will be utilized to produce flash x-ray holograms of the biological structures.

Trebes, J.; Annese, C.; Birdsall, D.; Brase, J.; Gray, J.; Lane, S.; London, R.; Matthews, D.; Peters, D.; Pinkel, D.; Stone, G.; Rapp, D.; Rosen, M.; Weier, U.; Yorkey, T.

1990-10-11T23:59:59.000Z

228

X-Ray Diffraction Microscopy of Magnetic Structures  

NLE Websites -- All DOE Office Websites (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...

229

X-ray diffraction study of zirconia pillared clays  

Science Journals Connector (OSTI)

X-ray powder diffraction (XRPD) and X-ray radial electronic distribution density (RED) of initial and zirconia-pillared interlayered clays (Zr-PILC) were studied. After pillaring, the basal ... under air to 17.7 ...

D.A. Zyuzin; E.M. Moroz; T.G. Kuznetsova…

2004-01-01T23:59:59.000Z

230

Development of a Schwarzschild-type x-ray microscope  

Science Journals Connector (OSTI)

A Schwarzschild-type x-ray microscope has been designed, constructed, and tested. Ni/C multilayers were used as the x-ray mirrors, with a thickness (2d) of 7 nm and 30 layer pairs. The...

Kado, M; Yamashita, K; Ohtani, M; Tanaka, K A; Kodama, R; Kitamoto, S; Yamanaka, T; Nakai, S

1991-01-01T23:59:59.000Z

231

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (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...

232

A Record Run for the APS X-ray Source  

NLE Websites -- All DOE Office Websites (Extended Search)

2004 | 2003 | 2002 | 2001 2000 Subscribe to APS News rss feed A Record Run for the APS X-ray Source FEBRUARY 23, 2012 Bookmark and Share The APS storage ring. X-ray beams and...

233

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

NLE Websites -- All DOE Office Websites (Extended Search)

Resonant Soft X-Ray Scattering - Combining Structural with Spectroscopic Refinement Friday, September 28, 2012 - 10:00am SLAC, Bldg. 137, Room 322 SSRL Presents Kevin Stone X-ray...

234

TENDER ENERGY X-RAY ABSORPTION  

NLE Websites -- All DOE Office Websites (Extended Search)

TENDER ENERGY X-RAY ABSORPTION TENDER ENERGY X-RAY ABSORPTION SPECTROSCOPY (TES) Project Team: S. Bare 1,2 , J. Brandes 3 , T. Buonassisi 4 , J. Chen 5,2 , M. Croft 6 , E. DiMasi 7 , A. Frenkel 8,2 , D. Hesterberg 9 , S. Hulbert 7,2 , S. Khalid 7 , S. Myneni 10 , P. Northrup 7,11 , E.T. Rasbury 11 , B. Ravel 12 , R. Reeder 11 , J. Rodriguez 7,2 , D. Sparks 5,13 , V. Stojanoff 7 , G. Waychunas 14 1 UOP LLC, 2 Synchrotron Catalysis Consortium, 3 Skidaway Inst. of Oceanography, 4 MIT Laboratory for Photovoltaics Research, 5 Univ. of Delaware, 6 Rutgers Univ., 7 Brookhaven National Lab, 8 Yeshiva Univ., 9 North Carolina State Univ., 10 Princeton Univ., 11 Stony Brook Univ., 12 NIST, 13 Delaware Environmental Inst., 14 Lawrence Berkeley National Lab TECHNIQUES: High performance and in-situ X-ray absorption spectroscopy and spatially-resolved XAS of

235

The X-ray Telescope of CAST  

E-Print Network (OSTI)

The Cern Axion Solar Telescope (CAST) is in operation and taking data since 2003. The main objective of the CAST experiment is to search for a hypothetical pseudoscalar boson, the axion, which might be produced in the core of the sun. The basic physics process CAST is based on is the time inverted Primakoff effect, by which an axion can be converted into a detectable photon in an external electromagnetic field. The resulting X-ray photons are expected to be thermally distributed between 1 and 7 keV. The most sensitive detector system of CAST is a pn-CCD detector combined with a Wolter I type X-ray mirror system. With the X-ray telescope of CAST a background reduction of more than 2 orders off magnitude is achieved, such that for the first time the axion photon coupling constant g_agg can be probed beyond the best astrophysical constraints g_agg < 1 x 10^-10 GeV^-1.

M. Kuster; H. Bräuninger; S. Cébrian; M. Davenport; C. Elefteriadis; J. Englhauser; H. Fischer; J. Franz; P. Friedrich; R. Hartmann; F. H. Heinsius; D. H. H. Hoffmann; G. Hoffmeister; J. N. Joux; D. Kang; K. Königsmann; R. Kotthaus; T. Papaevangelou; C. Lasseur; A. Lippitsch; G. Lutz; J. Morales; A. Rodríguez; L. Strüder; J. Vogel; K. Zioutas

2007-05-10T23:59:59.000Z

236

Applications of holography to x-ray imaging  

SciTech Connect

In this paper we consider various applications of holographic techniques to the problem of soft x-ray imaging. We give special attention to imaging biological material using x-rays in the wavelength range 24 to 45A. We describe some experiments on formation and reconstruction of x-ray holograms and propose some ways in which holographic techniques might contribute to the difficult problem of fabricating optical elements for use in the soft x-ray region.

Howells, M.; Iarocci, M.; Kenney, J.; Rarback, H.; Rosser, R.; Yun, W.

1985-03-01T23:59:59.000Z

237

Applications of holography to X-ray imaging  

SciTech Connect

In this paper the authors consider various applications of holographic techniques to the problem of soft x-ray imaging. Special attention is given to imaging biological material using x-rays in the wavelength range 24-45A. The authors describe some experiments on formation and reconstruction of x-ray holograms and propose some ways in which holographic techniques might contribute to the difficult problem of fabricating optical elements for use in the soft x-ray region.

Howells, M.; Iarocci, M.; Kenney, J.; Rarback, H.; Rosser, R.; Yun, W.

1985-01-01T23:59:59.000Z

238

X-ray MicroCT Training Presentation  

E-Print Network (OSTI)

X-ray MicroCT Training Presentation T. Fettah Kosar, PhD Center for Nanoscale Systems Harvard) Model: HMXST225 (max. 225 kV) #12;Overview 3 Introduction to X-ray imaging and Computed Tomography (CT) · What are X-rays and how do we generate and image them? · How do we magnify X-ray images and keep them

239

Comparison between pressurized design and ambient pressure design of hybrid solid oxide fuel cell–gas turbine systems  

Science Journals Connector (OSTI)

Design performances of the hybrid solid oxide fuel cell (SOFC)–gas turbine (GT) system have been investigated. A pressurized system and an indirectly heated ambient pressure system were analyzed and their performances were compared. In the baseline layout, the basic performance characteristics of the two system configurations were analyzed, with the cell operation temperature and the pressure ratio as the main design parameters. The pressurized system exhibits a better efficiency owing to not only the higher cell voltage but also more effective utilization of gas turbine, i.e., a larger GT power contribution due to a higher turbine inlet temperature. Independent setting of the turbine inlet temperature was simulated by using the additional fuel supply as well as the air bypass. Increasing the pressure ratio of the gas turbine hardly improves the system efficiency, but the efficiency becomes less sensitive to the turbine inlet temperature. In the ambient pressure system, the available design parameter range is much reduced due to the limit on the recuperator temperature. In particular, design of the ambient pressure hybrid system with a gas turbine of a high pressure ratio does not seem quite feasible because the system efficiency that can be achieved at the possible design conditions is even lower than the efficiency of the SOFC only system.

S.K. Park; T.S. Kim

2006-01-01T23:59:59.000Z

240

Quantitative x-ray imager (abstract)  

SciTech Connect

We report on development of a quantitative x-ray imager (QXI) for the national Inertial Confinement Fusion Program. Included in this development is a study of photocathode response as a function of photon energy, 2--17.5 keV, which is related to diagnostic development on the National Ignition Facility (NIF). The QXI is defined as being a quantative imager due to the repeated characterization. This instrument is systematically checked out, electronically as well as its photocathode x-ray response, both on a direct current and pulsed x-ray sources, before and after its use on a shot campaign. The QXI is a gated x-ray imager1 used for a variety of experiments conducted in the Inertial Confinement Fusion and Radiation Physics Program. The camera was assembled in Los Alamos and has been under development since 1997 and has now become the workhorse framing camera by the program. The electronics were built by Grant Applied Physics of San Fransisco, CA.2 The QXI has been used at the LANL Trident, LLNL Nova, and University of Rochester Laboratory OMEGA laser facilities. The camera consists of a grated microchannel plate (MCP), a phosphor coated fiberoptic faceplate coupled to film for data readout, along with high speed electronic pulsers to drive the x-ray detector. The QXI has both a two-strip and a four-strip detection head and has the ability to individually bias the gain of each of the strips. The timing of the QXI was done at the Trident short pulse laboratory, using 211 nm light. Single strip jitter was looked at as well and determined to be <25 ps. Flatfielding of the photocathode across the MCP was done with the Trident main laser with 150 J on a gold disk with a 1 ns. Spatial resolution was determined to be <5 {mu}m by using the same laser conditions as before and a backlit 1000 lp/in. grid. The QXI has been used on cylindrical implosion work at the Nova Laser Facility, and on direct-drive cylinder mix and indirect-drive high convergence implosion experiments at OMEGA. Its two-strip module has provided the capability to look at point backlighters, as part of technique development for experiments on the NIF. Its next use will be in March 2000 with its off axis viewer nose at Omega, providing a perpendicular view of Rayleigh--Taylor spike dissipation.

Evans, Scott C.; Archuleta, Tom N.; Oertel, John A.; Walsh, Peter J.

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

X-ray Microscopy and Imaging: 2-BM  

NLE Websites -- All DOE Office Websites (Extended Search)

BM BM Introduction The 2-BM beamline offers measurement capabilities for x-ray microtomography, x-ray topography and x-ray microdiffraction. X-ray microtomography and x-ray diffraction instruments are installed on separate optical tables for independent operation with fast switch over time. Optically-coupled high-resolution CCD system is used for microtomography and topography with up to 1 micron spatial resolution. X-ray microdiffraction setup consists of KB microfocussing mirrors (~3 micron minimum spot), four-circle Huber diffractometer, high-precision translation sample stage, two orthogonally-mounted video cameras for viewing sample, fluorescence detector (Si-drift diode) and diffraction detector (a scintillation detector or a CCD). Three different levels of monochromaticity are available. Conventional monochromatic x-rays from a double-bounced Si (111) crystal monochromator (DCM, D E/E=1E-4), wide band-pass monochromatic x-rays from a double multilayer monochromator (DMM, D E/E=1~4E-2) and pink beam. The available x-ray range is from 5 keV to 30 keV. The lower limit is due to the x-ray windows and the upper limit is due to the critical angle of the x-ray mirror. Two different coatings (Cr and Pt) for the x-ray mirror allow either 20 keV or 30 keV energy cutoff.

242

Improvement of YOHKOH Hard X-Ray Imaging  

Science Journals Connector (OSTI)

......Figure la shows the X-ray penetration rate through a single, 0.5 mm...index Fig. 1. (a) X-ray penetration rate through a single tung- sten...the K-escape. (b) X-ray penetration rates averaged over the HXT M2 and......

Jun Sato; Takeo Kosugi; Kazuo Makishima

1999-02-01T23:59:59.000Z

243

Small Angle X-ray Scattering (SAXS) Laboratory Learning Experiences  

E-Print Network (OSTI)

.A. & Svergun D.I. (1987). Structure Analysis by Small-Angle X-Ray and Neutron Scattering. NY: Plenum PressSmall Angle X-ray Scattering (SAXS) Laboratory Learning Experiences o - Use of small angle X-ray scattering instrumentation o - Programs that you will use SAXS (BRUKER AXS) PRIMUS (Konarev, Volkov, Koch

Meagher, Mary

244

X-ray Diffraction Laboratory Department of Chemistry  

E-Print Network (OSTI)

X-ray Diffraction Laboratory Department of Chemistry Texas A & M University College Station, Texas Phone : 979-845-9125 www.chem.tamu.edu/xray xray@tamu.edu X-rayDiffractionLaboratory DepartmentofChemistry 3255TAMU CollegeStation,TX77843-3255 Mission The purpose of our laboratory is to provide X-ray

Meagher, Mary

245

X-ray Diffraction Practicals 1 Graphics Programs  

E-Print Network (OSTI)

X-ray Diffraction Practicals 1 Graphics Programs that will read SHELX or CIF files J. Reibenspies, N. Bhuvanesh ver 1.0.0 #12;X-ray Diffraction Practicals 2 Free software. Gretep : Reads SHELX files shelx files or output thermal ellipsoid plots. http://www.umass.edu/microbio/rasmol/ #12;X-ray

Meagher, Mary

246

X-ray Emission from Massive Stars David Cohen  

E-Print Network (OSTI)

X-ray Emission from Massive Stars David Cohen Department of Physics and Astronomy Swarthmore University, Oct. 13, 2005 astro.swarthmore.edu/~cohen/ #12;Outline 1. What you need to know: a. X-rays from the Sun - magnetic activity, x-ray spectra b. Hot stars c. Radiation-driven winds and the Doppler shift d

Cohen, David

247

X-Ray Interactions with Matter from the Center for X-Ray Optics (CXRO)  

DOE Data Explorer (OSTI)

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.

Henke, B.L.; Gullikson, E.M.; Davis, J.C.

248

Generation of first hard X-ray pulse at Tsinghua Thomson Scattering X-ray Source  

SciTech Connect

Tsinghua Thomson Scattering X-ray Source (TTX) is the first-of-its-kind dedicated hard X-ray source in China based on the Thomson scattering between a terawatt ultrashort laser and relativistic electron beams. In this paper, we report the experimental generation and characterization of the first hard X-ray pulses (51.7 keV) via head-on collision of an 800 nm laser and 46.7 MeV electron beams. The measured yield is 1.0 Multiplication-Sign 10{sup 6} per pulse with an electron bunch charge of 200 pC and laser pulse energy of 300 mJ. The angular intensity distribution and energy spectra of the X-ray pulse are measured with an electron-multiplying charge-coupled device using a CsI scintillator and silicon attenuators. These measurements agree well with theoretical and simulation predictions. An imaging test using the X-ray pulse at the TTX is also presented.

Du Yingchao; Yan Lixin; Hua Jianfei; Du Qiang; Zhang Zhen; Li Renkai; Qian Houjun; Huang Wenhui; Chen Huaibi; Tang Chuanxiang [Accelerator Laboratory, Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Key Laboratory of Particle and Radiation Imaging, Tsinghua University, Ministry of Education, Beijing 100084 (China); Key Laboratory of High Energy Radiation Imaging Fundamental Science for National Defense, Tsinghua University, Beijing 100084 (China)

2013-05-15T23:59:59.000Z

249

Calibrating X-ray Imaging Devices for Accurate Intensity Measurement  

SciTech Connect

The purpose of the project presented is to develop methods to accurately calibrate X-ray imaging devices. The approach was to develop X-ray source systems suitable for this endeavor and to develop methods to calibrate solid state detectors to measure source intensity. NSTec X-ray sources used for the absolute calibration of cameras are described, as well as the method of calibrating the source by calibrating the detectors. The work resulted in calibration measurements for several types of X-ray cameras. X-ray camera calibration measured efficiency and efficiency variation over the CCD. Camera types calibrated include: CCD, CID, back thinned (back illuminated), front illuminated.

Haugh, M. J.

2011-07-28T23:59:59.000Z

250

Precision recording of near-edge profiles of x-ray absorption edges: an improved x-ray spectroscopy  

SciTech Connect

The intense, highly monochromatized X-ray beams available at the Cornell High Energy Synchroton Source facility permit one to plot the fine structure at absorption edges of elements with atomic number Z > 18. With the simple device described in this report, the authors have recorded distinctive features in absorption profiles, with a reproducibility better than +/- 50 meV for the major jumps, when measured with reference to a selected material, generally the metal. These spectra, which reflect locations of the upper states into which the photoelectrons are propelled, can be obtained without pretreatment of the sample (other than grinding to a fine powder) under ambient atmospheric conditions. Of course, spectra at low or high temperatures, under controlled atmospheres, can also be recorded with a more elaborative device. This technique complements information derived from electron energy loss spectroscopy and provides a fingerprint of modifications in the electronic structure of the element induced by the coordinating shell of surrounding atoms. It is a discriminating analytical probe for characterizing compositional changes in the first coordination shell around the selected atomic centers, due to processing of amorphous (or very finely divided) materials.

Chiu, N.S.; Bauer, S.H.

1988-08-01T23:59:59.000Z

251

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

SciTech Connect

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.

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

1999-05-01T23:59:59.000Z

252

X-Ray Source Based on the Parametric X-Rays  

E-Print Network (OSTI)

Prospects of parametric x-rays (PXR) application for the development of a tuneable quasi-monochromatic x-ray source for medical imaging are discussed. Analysis of basic requirements for electron accelerator shows that it must be relatively low-energy and high-current linac. In comparison with known ultra-relativistic cases, at low energies PXR properties will be modified to a great extent by multiple scattering of the electrons. PXR intensity dependence on target thickness and beam energy are calculated taking multiple scattering into account. It is concluded that PXR source based on real medical accelerators is feasible and can provide x-ray flux needful for obtaining high quality medical images.

Alexander Lobko; Olga Lugovskaya

2005-09-02T23:59:59.000Z

253

Apparatus for monitoring X-ray beam alignment  

DOE Patents (OSTI)

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.

Steinmeyer, Peter A. (Arvada, CO)

1991-10-08T23:59:59.000Z

254

Photon Sciences | Beamlines | HXN: Hard X-ray Nanoprobe  

NLE Websites -- All DOE Office Websites (Extended Search)

HXN: Hard X-ray Nanoprobe HXN: Hard X-ray Nanoprobe Poster | Fact Sheet | Preliminary Design Report Scientific Scope The Hard X-ray Nanoprobe beamline and endstation instruments (HXN) will be designed and constructed to explore new frontiers of hard x-ray microscopy applications with the highest achievable spatial resolution. Currently the available spatial resolution for scientific applications, provided by scanning x-ray microscopes in the hard x-ray regime, is limited to ~50nm, which is still insufficient for probing the nanoscale interfacial structures critical in determining properties and functionalities of material and biological systems. The HXN beamline aims to enable x-ray experiments at spatial resolutions ranging from 10 to 30 nm with an ultimate goal of ~1 nm. Beamline Description

255

Introduction to Neutron and X-Ray Scattering  

NLE Websites -- All DOE Office Websites (Extended Search)

Scattering Studies of Thin Scattering Studies of Thin Polymer Films Introduction to Neutron and X-Ray Scattering Sunil K. Sinha UCSD/LANL Acknowledgements: Prof. R.Pynn( Indiana U.) Prof. M.Tolan (U. Dortmund) Wilhelm Conrad Röntgen 1845-1923 1895: Discovery of X-Rays 1901 W. C. Röntgen in Physics for the discovery of x-rays. 1914 M. von Laue in Physics for x-ray diffraction from crystals. 1915 W. H. Bragg and W. L. Bragg in Physics for crystal structure determination. 1917 C. G. Barkla in Physics for characteristic radiation of elements. 1924 K. M. G. Siegbahn in Physics for x-ray spectroscopy. 1927 A. H. Compton in Physics for scattering of x-rays by electrons. 1936 P. Debye in Chemistry for diffraction of x-rays and electrons in gases.

256

Hard X-ray tails and cyclotron features in X-ray pulsars  

E-Print Network (OSTI)

We review the physical processes occurring in the magnetosphere of accreting X-ray pulsars, with emphasis on those processes that give rise to observable effects in their high (E>10 keV) energy spectra. In the second part we compare the empirical spectral laws used to fit the observed spectra with theoretical models, at the light of the BeppoSAX results on the broad-band characterization of the X-ray pulsar continuum, and the discovery of new (multiple) cyclotron resonance features.

Mauro Orlandini; Daniele Dal Fiume

2001-07-27T23:59:59.000Z

257

The constellation X-ray mission  

Science Journals Connector (OSTI)

The Constellation-X mission is a large collecting area X-ray facility emphasizing observations at high spectral resolution (E/?E?300–3000) while covering a broad energy band (0.25–40 keV). This mission will achieve a factor of 100 increased sensitivity over current capabilities and is optimized to observe the effects of extreme gravity close to black holes and test models for the formation of large scale structure in the Universe. It is apart of NASA’s strategic plan for launch towards the end of the first decade of the 21st century.

N. E. White; H. Tananbaum

2001-01-01T23:59:59.000Z

258

13 - X-ray and Neutron Scattering  

Science Journals Connector (OSTI)

Abstract This chapter describes the use of neutrons and X-rays as probes in the study of structural and dynamic properties of metallic materials. Crystalline materials are characterized by their diffraction peaks related to their average crystallographic structure. In real crystals, locally displaced atoms and chemically (or isotopically for neutrons) different species may lead not only to changes of peak shapes and positions, but also to additional (diffuse) scattering between Bragg peak, including scattering around the primary beam (small-angle scattering). All these features can be used to extract information about the state of a sample, its compositional and structural variations on a scale depending on the scattering, in static and time-resolved kinetic studies. Energy-resolved scattering also offers an insight into solid-state dynamics on a microscopic scale. Some of the most important methods will be described and illustrated by instructive examples. The presentation offers a combined view of neutron and X-ray scattering, with the necessary simplifications dictated by space limitations. The special properties of thermal neutrons and of hard X-rays (now widely available at synchrotron radiation sources), their mutual combination, and combinations with other methods, in particular electron microscopy, offer ample opportunity to better understand and control materials properties. After a brief introduction to scattering from real crystals and some general ideas about long-range strains and Bragg peaks, the vicinity of Bragg peaks (displacement scattering at large scattering angles), the scattering far away from Bragg peaks (chemical heterogeneities, short-range order), and, in greater detail, small-angle scattering (which is not sensitive to the extent of crystallinity, but to nanoscale variations of chemical composition and of magnetization, precipitation) will be described, along with classical and more recent applications related to short-range ordering and precipitation in bulk and nanostructured alloys. Some other fields are only briefly addressed (grazing-incidence studies of surfaces, radiography, absorption spectroscopies, coherent X-rays). The final section offers some information on the influence of defects on lattice dynamics and on (slow) diffusive motion in materials.

Gernot Kostorz

2014-01-01T23:59:59.000Z

259

X-Ray Diffraction on NIF  

SciTech Connect

The National Ignition Facility (NIF) is currently a 192 beam, 1.6 MJ laser. NIF Ramp-Compression Experiments have already made the relevant exo-planet pressure range from 1 to 50 Mbar accessible. We Proposed to Study Carbon Phases by X-Ray Diffraction on NIF. Just a few years ago, ultra-high pressure phase diagrams for materials were very 'simple'. New experiments and theories point out surprising and decidedly complex behavior at the highest pressures considered. High pressures phases of aluminum are also predicted to be complex. Recent metadynamics survey of carbon proposed a dynamic pathway among multiple phases. We need to develop diagnostics and techniques to explore this new regime of highly compressed matter science. X-Ray Diffraction - Understand the phase diagram/EOS/strength/texture of materials to 10's of Mbar. Strategy and physics goals: (1) Powder diffraction; (2) Begin with diamond; (3) Continue with metals etc.; (4) Explore phase diagrams; (5) Develop liquid diffraction; and (6) Reduce background/improve resolution.

Eggert, J H; Wark, J

2012-02-15T23:59:59.000Z

260

Development of procedures for refurbishing x-ray optics at the Advanced Light Source  

E-Print Network (OSTI)

Development of procedures for refurbishing x-ray optics atpractical and robust procedures for refurbishing x-ray

Yashchuk, Valeriy V.

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Photon Sciences | Beamlines | IXS: Inelastic X-ray Scattering  

NLE Websites -- All DOE Office Websites (Extended Search)

IXS: Inelastic X-ray Scattering IXS: Inelastic X-ray Scattering Poster | Fact Sheet | Preliminary Design Report Scientific Scope Many hot topics related to the high frequency dynamics of condensed matter require both a narrower and steeper resolution function and access to a broader dynamic range than what are currently available. This represents a sort of "no man's land" that falls right in the dynamic gap lying between the high frequency spectroscopies, such as inelastic x-ray scattering (IXS), and the low frequency ones. New IXS spectrometers with improved energy and momentum resolutions would be required to fill this gap. To achieve this goal, a new x-ray optics concept for both the monochromatization and energy analysis of x-rays will be implemented at the NSLS-II Inelastic X-ray Scattering beamline. This solution exploits the

262

X-Ray Fluorescence (XRF) | Open Energy Information  

Open Energy Info (EERE)

X-Ray Fluorescence (XRF) X-Ray Fluorescence (XRF) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: X-Ray Fluorescence (XRF) Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Lab Analysis Techniques Exploration Sub Group: Rock Lab Analysis Parent Exploration Technique: Rock Lab Analysis Information Provided by Technique Lithology: Bulk and trace element analysis of rocks, minerals, and sediments. Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png X-Ray Fluorescence (XRF): X-Ray Fluorescence is a lab-based technique used for bulk chemical analysis of rock, mineral, sediment, and fluid samples. The technique depends on the fundamental principles of x-ray interactions with solid materials, similar

263

X-Ray Diffraction Microscopy of Magnetic Structures  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Diffraction Microscopy of Magnetic Structures Print 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 electron density of complicated molecules. The formula used to make these calculations contains terms that relate to the electron spin of magnetic atoms, but these terms are traditionally ignored since coherent x-ray diffraction has not been used to retrieve magnetic information. Using the full formula allows for the determination of not only the electron density, but also the magnetic spin distribution and its orientation.

264

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print 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 imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

265

APS 7-BM Beamline: X-Ray Resources  

NLE Websites -- All DOE Office Websites (Extended Search)

Useful Websites Useful Websites X-Ray Interactions with Matter from CRXO at LBNL. Intuitive interface for x-ray transmission and reflectivity for a wide range of materials. X-Ray Data Booklet from LBNL. Slightly outdated in places, but many useful tables of edge energies, fluorescence lines, and crystal lattice spacings. NIST XCOM Database. Powerful database of photoelectric absorption, elastic scattering, and Compton scattering cross-sections for a wide range of materials. X-Ray Server. Maintained by Sergey Stepanov at GMCA at the APS, this website has several powerful calculators for simulating x-ray reflection and diffraction. Software X-Ray Oriented Programs (XOP). This program, written by scientists at the ESRF and APS, is widely used in the synchrotron research community.

266

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print 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 imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

267

X-Ray Diffraction Microscopy of Magnetic Structures  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Diffraction Microscopy of Magnetic Structures Print 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 electron density of complicated molecules. The formula used to make these calculations contains terms that relate to the electron spin of magnetic atoms, but these terms are traditionally ignored since coherent x-ray diffraction has not been used to retrieve magnetic information. Using the full formula allows for the determination of not only the electron density, but also the magnetic spin distribution and its orientation.

268

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print 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 imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

269

Definition: X-Ray Diffraction (XRD) | Open Energy Information  

Open Energy Info (EERE)

X-Ray Diffraction (XRD) X-Ray Diffraction (XRD) Jump to: navigation, search Dictionary.png X-Ray Diffraction (XRD) X-Ray Diffraction (XRD) is a laboratory-based technique commonly used for identification of crystalline materials and analysis of unit cell dimensions. One of two primary types of XRD analysis (X-ray powder diffraction and single-crystal XRD) is commonly applied to samples to obtain specific information about the crystalline material under investigation. X-ray powder diffraction is widely used in geology, environmental science, material science, and engineering to rapidly identify unknown crystalline substances (typically in less than 20 minutes). A pure, finely ground, and homogenized sample is required for determination of the bulk composition. Additional uses include detailed

270

X-Ray Diffraction Microscopy of Magnetic Structures  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Diffraction Microscopy of Magnetic Structures Print 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 electron density of complicated molecules. The formula used to make these calculations contains terms that relate to the electron spin of magnetic atoms, but these terms are traditionally ignored since coherent x-ray diffraction has not been used to retrieve magnetic information. Using the full formula allows for the determination of not only the electron density, but also the magnetic spin distribution and its orientation.

271

X-Ray Diffraction (XRD) | Open Energy Information  

Open Energy Info (EERE)

X-Ray Diffraction (XRD) X-Ray Diffraction (XRD) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: X-Ray Diffraction (XRD) Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Lab Analysis Techniques Exploration Sub Group: Rock Lab Analysis Parent Exploration Technique: Rock Lab Analysis Information Provided by Technique Lithology: Rapid and unambiguous identification of unknown minerals.[1] Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png X-Ray Diffraction (XRD): X-Ray Diffraction (XRD) is a laboratory-based technique commonly used for identification of crystalline materials and analysis of unit cell dimensions. One of two primary types of XRD analysis (X-ray powder diffraction and single-crystal XRD) is commonly applied to samples to

272

Density gradient free electron collisionally excited X-ray laser  

DOE Patents (OSTI)

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.

Campbell, Edward M. (Pleasanton, CA); Rosen, Mordecai D. (Berkeley, CA)

1989-01-01T23:59:59.000Z

273

Density gradient free electron collisionally excited x-ray laser  

DOE Patents (OSTI)

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.

Campbell, E.M.; Rosen, M.D.

1984-11-29T23:59:59.000Z

274

Formation of microbeam using tabletop soft X-ray laser  

Science Journals Connector (OSTI)

An X-ray microprobe with a sub-micron size beam and high intensity can provide X-ray analyses with a remarkable spatial resolution. We have performed focusing of an X-ray laser output into a sub-micron beam for the first time. In our experiment, an X-ray laser of Li-like Al 3d–4f transition at 15.47 nm was delivered from an unstable cavity consisting of a concave mirror and a flat mirror with a square orifice of 100×100 ?m in size. The beam from the orifice was then focused by using a Schwarzschild mirror coated with a Mo/Si multilayer. An X-ray beam size with a diameter of about 0.45 ?m and an estimated photon number of about 2×106 photons per shot was achieved. Such sources could be well suited for the realization of X-ray microprobes.

Tadayuki Ohchi; Naohiro Yamaguchi; Chiemi Fujikawa; Tamio Hara

1999-01-01T23:59:59.000Z

275

Portable X-Ray Diffraction (XRD) | Open Energy Information  

Open Energy Info (EERE)

Portable X-Ray Diffraction (XRD) Portable X-Ray Diffraction (XRD) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Portable X-Ray Diffraction (XRD) Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Field Techniques Exploration Sub Group: Data Collection and Mapping Parent Exploration Technique: Data Collection and Mapping Information Provided by Technique Lithology: Rapid and unambiguous identification of unknown minerals.[1] Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png Portable X-Ray Diffraction (XRD): Portable X-Ray Diffraction (XRD) is a field-based technique that can be used for identification of crystalline materials and analysis of unit cell dimensions. Portable XRD analysis is similar to X-ray powder diffraction,

276

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print 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 imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

277

X-ray Pinhole Camera Measurements  

SciTech Connect

The rod pinch diode is made up of a cathode plate and a small diameter anode rod that extends through the cathode hole. The anode is charged positively. The rod tip is made of a high-z material which is chosen for its bremsstrahlung efficiency. When the diode is pulsed it produces an intense x-ray source used for pulsed radiography. The baseline or reference diode consists of a 0.75 mm diameter Tungsten (W) tapered anode rod which extends 10 mm through a 9 mm diameter 3 mm thick aluminum (Al) aperture. The majority of the current in the electron beam is created on the edges of the cathode aperture and when properly configured, the electrons will self insulate, travel down the extension of the rod, and pinch onto the tip of the rod. In this presentation, performance of hybrid diodes will be compared with the baseline diode.

Nelson, D. S. [NSTec; Berninger, M. J. [NSTec; Flores, P. A. [NSTec; Good, D. E. [NSTec; Henderson, D. J. [NSTec; Hogge, K. W. [NSTec; Huber, S. R. [NSTec; Lutz, S. S. [NSTec; Mitchell, S. E. [NSTec; Howe, R. A. [NSTec; Mitton, C. V. [NSTec; Molina, I. [NSTec; Bozman, D. R. [SNL; Cordova, S. R. [SNL; Mitchell, D. R. [SNL; Oliver, B. V. [SNL; Ormond, E. C. [SNL

2013-06-20T23:59:59.000Z

278

Gray scale x-ray mask  

DOE Patents (OSTI)

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.

Morales, Alfredo M. (Livermore, CA); Gonzales, Marcela (Seattle, WA)

2006-03-07T23:59:59.000Z

279

Nonlinear optics with focused x-ray lasers  

SciTech Connect

We have investigated the possibility of focusing x-ray lasers with the use of multilayered mirrors or zone plates. The results indicate that x-ray intensities as high as 10{sup 14} W/cm{sup 2} can be achieved by focusing saturated Ne-like x-ray lasers. These intensities should be adequate for studying nonlinear optical phenomena. 9 refs., 2 figs.

DaSilva, L.B.; Muendel, M.H.; Falcone, R.W.; Fields, D.J.; Kortright, J.B.; MacGowan, B.J.; Matthews, D.L.; Mrowka, S.; Shimkaveg, G.M.; Trebes, J.E.

1990-12-12T23:59:59.000Z

280

Process and device for x-ray system quality assurance  

SciTech Connect

This invention relates to medical radiography test systems, and more particularly to a method and apparatus for providing evaluation of a medical or dental x-ray system consisting of x-ray generator, film and processor on a daily basis and to thereby assure the production of useful radiographs from the system with no need to repeat patient exposure because of problems with the x-ray system.

Van Pelt, W.F.; Peterson, R.W.

1982-11-10T23:59:59.000Z

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

The first X-ray diffraction measurements on Mars  

Science Journals Connector (OSTI)

The X-ray diffraction/X-ray fluorescence instrument CheMin on the Curiosity rover is a shoebox-sized device using transmission geometry and an energy-discriminating CCD detector. The instrument has returned the first X-ray diffraction data for soil and drilled samples from Mars outcrops, revealing a suite of primary basaltic minerals, amorphous components and varied hydrous alteration products including phyllosilicates.

Bish, D.

2014-10-21T23:59:59.000Z

282

On X-Ray Waveguiding in Nanochannels: Channeling Formalism  

E-Print Network (OSTI)

The question on X-ray extreme focusing (smallest reachable spot size) brings us to the idea for using the wave features of X-ray propagation in media. As known, wave features are revealed at propagation in ultra-narrow collimators as well as at glancing reflection from smooth flat and/or strongly curved surfaces. All these phenomena can be described within the general formalism of X-ray channeling.

S. B. Dabagov

2006-11-20T23:59:59.000Z

283

THE GEODESIC X-RAY TRANSFORM WITH FOLD CAUSTICS The ...  

E-Print Network (OSTI)

Aug 28, 2012 ... THE GEODESIC X-RAY TRANSFORM WITH FOLD CAUSTICS. PLAMEN STEFANOV AND GUNTHER UHLMANN. ABSTRACT. We give a ...

2012-08-28T23:59:59.000Z

284

Inelastic X-ray and Nuclear Resonant Scattering  

NLE Websites -- All DOE Office Websites (Extended Search)

... Search About User Information News & Events Science & Education Beamlines Divisions Argonne Home > Advanced Photon Source > Inelastic X-ray and Nuclear Resonant Scattering...

285

Advances in X-Ray Diagnostics of Diesel Fuel Sprays  

Energy.gov (U.S. Department of Energy (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.

286

New intraoral x-ray fluorographic imaging for dentistry  

SciTech Connect

A new dental x-ray fluorographic unit has been developed. This unit is composed of small intraoral x-ray tube, a compact x-ray image intensifier, and a high-resolution TV system. The purposes for developing this equipment were to (1) directly observe the tooth during endodontic procedures and (2) reduce x-ray exposure to the patient and the dentist. The radiation exposure can be reduced to about 1/600 the exposure used with conventional dental film. In clinical trials, a satisfactory fluorographic dental image for endodontic treatment was obtained with this new device.

Higashi, T.; Osada, T.; Aoyama, W.; Iguchi, M.; Suzuki, S.; Kanno, M.; Moriya, K.; Yoshimura, M.; Tusuda, M.

1983-06-01T23:59:59.000Z

287

Normal incidence x-ray mirror for chemical microanalysis  

DOE Patents (OSTI)

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.

Carr, M.J.; Romig, A.D. Jr.

1987-08-05T23:59:59.000Z

288

Self-terminating diffraction gates femtosecond X-ray nanocrystallograp...  

NLE Websites -- All DOE Office Websites (Extended Search)

Self-terminating diffraction gates femtosecond X-ray nanocrystallography measurements Authors: Barty, A., Caleman, C., Aquila, A., Timneanu, N., Lomb, L., White, T. A., Andreasson,...

289

High intensity x-ray source using liquid gallium target  

DOE Patents (OSTI)

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.

Smither, Robert K. (Hinsdale, IL); Knapp, Gordon S. (Cupertino, CA); Westbrook, Edwin M. (Chicago, IL); Forster, George A. (Westmont, IL)

1990-01-01T23:59:59.000Z

290

X-ray Diffuse Scattering Measurements of Nucleation Dynamics...  

NLE Websites -- All DOE Office Websites (Extended Search)

X-ray Diffuse Scattering Measurements of Nucleation Dynamics at Femtosecond Resolution Real-time measurement and control of the non-equilibrium properties of materials represents...

291

XRMS: X-Ray Spectroscopy of Magnetic Solids  

NLE Websites -- All DOE Office Websites (Extended Search)

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

292

X-ray absorption fine structure and magnetization characterization...  

NLE Websites -- All DOE Office Websites (Extended Search)

characterization of the metallic Co component in Co-doped ZnO thin films . X-ray absorption fine structure and magnetization characterization of the metallic Co...

293

Characterization Testing of H20-SO2 Electrolyzer at Ambient Pressure  

SciTech Connect

This document reports work performed at the Savannah River National Laboratory (SRNL) that resulted in a major accomplishment by demonstrating the proof-of-concept of the use of a proton exchange membrane or PEM-type electrochemical cell to produce hydrogen via SO{sub 2}-depolarized water electrolysis. For the first time sulfur dioxide dissolved in liquid sulfuric acid was used to depolarize water electrolysis in a modern PEM cell. The use of such a cell represents a major step in achieving the ultimate goal of an economical hydrogen production process based on the Hybrid Sulfur (HyS) Cycle. The HyS Process is a hybrid thermochemical cycle that may be used in conjunction with advanced nuclear reactors or centralized solar receivers to produce hydrogen by water-splitting. Like all other sulfur-based cycles, HyS utilizes the high temperature thermal decomposition of sulfuric acid to produce oxygen. The unique aspect of HyS is the generation of hydrogen in a water electrolyzer that is operated under conditions where dissolved sulfur dioxide depolarizes the anodic reaction, resulting in substantial voltage reduction. Sulfur dioxide is oxidized at the anode, producing sulfuric acid, that is sent to the acid decomposition portion of the cycle. The focus of this work was to conduct single cell electrolyzer tests in order to prove the concept of SO{sub 2}-depolarization and to determine how the results can be used to evaluate the performance of key components of the HyS Process. A test facility for conducting SO{sub 2}-depolarized electrolyzer (SDE) testing was designed, constructed and commissioned. The maximum cell current is 50 amperes, which is equivalent to a hydrogen production rate of approximately 20 liters per hour. The test facility was designed for operation at room temperature with pressures up to 2 bar. Feed to the anode of the electrolyzer can be water, sulfuric acid of various concentrations, or sulfuric acid containing dissolved sulfur dioxide. Provisions are included to allow variation of the operating pressure in the range of 1 to 2 bar. Hydrogen generated at the cathode of the cell can be collected for the purpose of flow measurement and composition analysis. The test facility proved to be easy to operate, versatile, and reliable. Two slightly different SDE's were designed, procured and tested. The first electrolyzer was based on a commercially available PEM water electrolyzer manufactured by Proton Energy Systems, Inc. (PES). The PES electrolyzer was built with Hastelloy B and Teflon wetted parts, a PEM electrolyte, and porous titanium electrodes. The second electrolyzer was assembled for SRNL by the University of South Carolina (USC). It was constructed with platinized carbon cloth electrodes, a Nafion 115 PEM electrolyte, carbon paper flow fields, and solid graphite back plates. Proof-of-concept testing was performed on each electrolyzer at near-ambient pressure and room temperature under various feed conditions. SDE operation was evidenced by hydrogen production at the cathode and sulfuric acid production at the anode (witnessed by the absence of oxygen generation) and with cell voltages substantially less than the theoretical reversible voltage for simple water electrolysis (1.23 V). Cell performance at low currents equaled or exceeded that achieved in the two-compartment cells built by Westinghouse Electric Corporation during the original development of the HyS Process. Performance at higher currents was less efficient due to mass transfer and hydraulic issues associated with the use of cells not optimized for liquid feed. Test results were analyzed to determine performance trends, improvement needs, and long-term SDE potential. The PES cell failed after several days of operation due to internal corrosion of the titanium electrodes in the presence of sulfuric acid. Although it was anticipated that the titanium would react in the presence of acid, the rapid deterioration of the electrodes was unexpected. The USC cell was constructed of carbon-based components and had excellent corrosion resistance. Howeve

Steimke, J

2005-07-29T23:59:59.000Z

294

X-Ray Photoelectron Spectroscopy Studies of Silicate Glasses: Implications to Bonding and Leaching  

Science Journals Connector (OSTI)

Technical Paper / Argonne National Laboratory Specialists’ Workshop on Basic Research Needs for Nuclear Waste Management / Radioactive Waste

B. W. Veal; D. J. Lam; A. P. Paulikas; D. P. Karim

295

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

Energy.gov (U.S. Department of Energy (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.

296

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

E-Print Network (OSTI)

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

Rubner, Michael F.

297

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

Science Journals Connector (OSTI)

...andbMaterials Science and Engineering, Massachusetts Institute of Technology, Cambridge...light-emitting diode devices (14), solar cells (15), and on-demand...higher-efficiency dye-sensitized solar cells (15) or ordering of the internal...low-temperature dye-sensitized solar cells . J Mater Chem 22 ( 22...

Jonathan B. Gilbert; Michael F. Rubner; Robert E. Cohen

2013-01-01T23:59:59.000Z

298

X-ray laser system, x-ray laser and method  

DOE Patents (OSTI)

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.

London, Richard A. (Oakland, CA); Rosen, Mordecai D. (Berkeley, CA); Strauss, Moshe (Omer, IL)

1992-01-01T23:59:59.000Z

299

Constraints on jet X-ray emission in low/hard state X-ray binaries  

E-Print Network (OSTI)

We show that the combination of the similarities between the X-ray properties of low luminosity accreting black holes and accreting neutron stars, combined with the differences in their radio properties argues that the X-rays from these systems are unlikely to be formed in the relativistic jets. Specifically, the spectra of extreme island state neutron stars and low/hard state black holes are known to be indistinguishable, while the power spectra from these systems are known to show only minor differences beyond what would be expected from scaling the characteristic variability frequencies by the mass of the compact object. The spectral and temporal similarities thus imply a common emission mechanism that has only minor deviations from having all key parameters scaling linearly with the mass of the compact object, while we show that this is inconsistent with the observations that the radio powers of neutron stars are typically about 30 times lower than those of black holes at the same X-ray luminosity. We also show that an abrupt luminosity change would be expected when a system makes a spectral state transition from a radiatively inefficient jet dominated accretion flow to a thin disk dominated flow, but that such a change is not seen.

Thomas J. Maccarone

2005-03-31T23:59:59.000Z

300

Isotropic star in low-mass X-ray binaries and X-ray pulsars  

E-Print Network (OSTI)

We present a model for compact stars in the low mass X-ray binaries(LMXBs) and X-ray pulsars using a metric given by John J. Matese and Patrick G. Whitman \\citep{Matese and Whitman1980}. Here the field equations are reduced to a system of two algebraic equations considering the isotropic pressure. Compact star candidates 4U 1820-30(radius=10km) in LMXBs, and Her X-1(radius=7.7km), SAX J 1808.4-3658(SS1)(radius=7.07km) and SAX J 1808.4-3658(SS2)(radius=6.35km) in X-ray pulsars satisfy all the energy conditions, TOV-equation and stability condition. From our model, we have derived mass($M$), central density($\\rho_{0}$), suface density($\\rho_{b}$), central pressure($p_{0}$), surface pressure($p_{b}$) and surface red-shift($Z_{s}$) of the above mentioned stars, which are very much consistant with the observed/reported datas\\citep{N. K. Glendenning1997,Gondek2000}. We have also observe the adiabatic index($\\gamma$>4/3) of the above steller objects.

Mehedi Kalam; Sk. Monowar Hossein; Sajahan Molla

2014-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

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

SciTech Connect

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 (?E/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.

Katayama, Tetsuo; Togashi, Tadashi; Tono, Kensuke; Kameshima, Takashi [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan)] [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Inubushi, Yuichi; Sato, Takahiro; Hatsui, Takaki; Yabashi, Makina [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)] [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Obara, Yuki; Misawa, Kazuhiko [Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan)] [Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan); Bhattacharya, Atanu; Kurahashi, Naoya [Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan)] [Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan); Ogi, Yoshihiro [Molecular Reaction Dynamics Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako 351-0198 (Japan)] [Molecular Reaction Dynamics Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako 351-0198 (Japan); Suzuki, Toshinori [Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan) [Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan); Molecular Reaction Dynamics Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako 351-0198 (Japan)

2013-09-23T23:59:59.000Z

302

Burning plasmas with ultrashort soft-x-ray flashing  

SciTech Connect

Fast ignition with narrow-band coherent x-ray pulses has been revisited for cryogenic deuterium-tritium (DT) plasma conditions achieved on the OMEGA Laser System. In contrast to using hard-x-rays (hv = 3-6 keV) proposed in the original x-ray fast-ignition proposal, we find that soft-x-ray sources with hv Almost-Equal-To 500 eV photons can be suitable for igniting the dense DT-plasmas achieved on OMEGA. Two-dimensional radiation-hydrodynamics simulations have identified the break-even conditions for realizing such a 'hybrid' ignition scheme (direct-drive compression with soft-x-ray heating) with 50-{mu}m-offset targets: {approx}10 ps soft-x-ray pulse (hv Almost-Equal-To 500 eV) with a total energy of 500-1000 J to be focused into a 10 {mu}m spot-size. A variety of x-ray pulse parameters have also been investigated for optimization. It is noted that an order of magnitude increase in neutron yield has been predicted even with x-ray energy as low as {approx}50 J. Scaling this idea to a 1 MJ large-scale target, a gain above {approx}30 can be reached with the same soft-x-ray pulse at 1.65 kJ energy. Even though such energetic x-ray sources do not currently exist, we hope that the proposed ignition scheme may stimulate efforts on generating powerful soft-x-ray sources in the near future.

Hu, S. X.; Goncharov, V. N.; Skupsky, S. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States)

2012-07-15T23:59:59.000Z

303

Combined energy dispersive EXAFS and x?ray diffraction  

Science Journals Connector (OSTI)

An in situ experiment to measure both x?ray absorption spectroscopy and x?ray diffraction of aurichalcite is described. The experiment uses position sensitive detectors to enable both data sets to be collected while the sample is slowly decomposed in air and then reduced in hydrogen. ?

A. J. Dent; M. P. Wells; R. C. Farrow; C. A. Ramsdale; G. E. Derbyshire; G. N. Greaves; J. W. Couves; J. M. Thomas

1992-01-01T23:59:59.000Z

304

Fresnel and refractive lenses for X-rays  

Science Journals Connector (OSTI)

We present a Gaussian beam analysis of X-ray refractive and Fresnel lenses. The X-ray refractive lens is featured by an intrinsic soft (Gaussian) aperture due to strong absorption of X-rays by materials. We defined a parameter N0, the critical Fresnel number (CFN), to describe this optical property. The values of N0 for all practical materials are below 1000 for photon energies exceeding 30 eV, still lower for high-Z materials. The maximum effective Fresnel number of a lens is determined by its material to be 2N0 and its maximum enhancement of X-ray intensity is limited to (2?N0)2, independent of its shape. We found that the refractive lens is likely to be useful for manipulating nearly diffraction limited beam in the hard X-ray region and its application is severely restricted by available fabrication capabilities today. X-ray Fresnel lenses, both in cylindrical and linear forms, are proposed as superior focusing elements for hard X-rays. Their high efficiency, up to 100% in optimal construction, will enable us to manipulate beams with multiple lenses and obtain higher performance optics. Their design and fabrication are discussed in reference to those of X-ray Fresnel zone plates and micro Fresnel lenses for optoelectronics.

B.X. Yang

1993-01-01T23:59:59.000Z

305

X-ray attenuation properties of stainless steel (u)  

SciTech Connect

Stainless steel vessels are used to enclose solid materials for studying x-ray radiolysis that involves gas release from the materials. Commercially available stainless steel components are easily adapted to form a static or a dynamic condition to monitor the gas evolved from the solid materials during and after the x-ray irradiation. Experimental data published on the x-ray attenuation properties of stainless steel, however, are very scarce, especially over a wide range of x-ray energies. The objective of this work was to obtain experimental data that will be used to determine how a poly-energetic x-ray beam is attenuated by the stainless steel container wall. The data will also be used in conjunction with MCNP (Monte Carlos Nuclear Particle) modeling to develop an accurate method for determining energy absorbed in known solid samples contained in stainless steel vessels. In this study, experiments to measure the attenuation properties of stainless steel were performed for a range of bremsstrahlung x-ray beams with a maximum energy ranging from 150 keV to 10 MeV. Bremsstrahlung x-ray beams of these energies are commonly used in radiography of engineering and weapon components. The weapon surveillance community has a great interest in understanding how the x-rays in radiography affect short-term and long-term properties of weapon materials.

Wang, Lily L [Los Alamos National Laboratory; Berry, Phillip C [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

306

Shining Soft X-rays on Magnetic Structures  

Science Journals Connector (OSTI)

...2) demonstrate the power of x-ray magneto-optics in a synchroton study of single crystalline FePd layers, which provides...2) demonstrate the power of x-ray magneto-optics in a synchroton study of single crystalline FePd layers, which provides detailed...

Ulrich Hillebrecht

1999-06-25T23:59:59.000Z

307

Human genome sequencing with direct x-ray holographic imaging  

SciTech Connect

Direct holographic imaging of biological materials is widely applicable to the study of the structure, properties and action of genetic material. This particular application involves the sequencing of the human genome where prospective genomic imaging technology is composed of three subtechnologies, name an x-ray holographic camera, suitable chemistry and enzymology for the preparation of tagged DNA samples, and the illuminator in the form of an x-ray laser. We report appropriate x-ray camera, embodied by the instrument developed by MCR, is available and that suitable chemical and enzymatic procedures exist for the preparation of the necessary tagged DNA strands. Concerning the future development of the x-ray illuminator. We find that a practical small scale x-ray light source is indeed feasible. This outcome requires the use of unconventional physical processes in order to achieve the necessary power-compression in the amplifying medium. The understanding of these new physical mechanisms is developing rapidly. Importantly, although the x-ray source does not currently exist, the understanding of these new physical mechanisms is developing rapidly and the research has established the basic scaling laws that will determine the properties of the x-ray illuminator. When this x-ray source becomes available, an extremely rapid and cost effective instrument for 3-D imaging of biological materials can be applied to a wide range of biological structural assays, including the base-pair sequencing of the human genome and many questions regarding its higher levels of organization.

Rhodes, C.K.

1993-06-08T23:59:59.000Z

308

Twelfth National School on Neutron and X-ray Scattering  

E-Print Network (OSTI)

Twelfth National School on Neutron and X-ray Scattering June 12 � June 26, 2010 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne

Pennycook, Steve

309

National School on Neutron and X-ray Scattering  

E-Print Network (OSTI)

National School on Neutron and X-ray Scattering May 30 � June 13, 2009 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne

Pennycook, Steve

310

National School on Neutron and X-ray Scattering  

E-Print Network (OSTI)

15th National School on Neutron and X-ray Scattering August 10 - 24, 2013 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major Ridge National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang

311

Fourteenth National School on Neutron and X-ray Scattering  

E-Print Network (OSTI)

Fourteenth National School on Neutron and X-ray Scattering August 12 - 25, 2012 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major Ridge National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang

Pennycook, Steve

312

Thirteenth National School on Neutron and X-ray Scattering  

E-Print Network (OSTI)

Thirteenth National School on Neutron and X-ray Scattering June 11 ­ June 25, 2011 at Argonne of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne

313

Neutron and X-ray Scattering Study of Magnetic Manganites  

E-Print Network (OSTI)

Neutron and X-ray Scattering Study of Magnetic Manganites Graeme Eoin Johnstone A Thesis submitted are performed using a variety of neutron scattering and x-ray scattering techniques. The electronic ground for analysing the results of the polarised neutron scattering experiment. There are a large number of people who

Boothroyd, Andrew

314

Sixteenth National School on Neutron and X-ray Scattering  

E-Print Network (OSTI)

Sixteenth National School on Neutron and X-ray Scattering June 14-28, 2014 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major's Neutron Scattering Science Division. Scientific Directors: Suzanne G.E. te Velthuis, Esen Ercan Alp

Pennycook, Steve

315

Tenth National School on Neutron and X-ray Scattering  

E-Print Network (OSTI)

Tenth National School on Neutron and X-ray Scattering September 24 - October 11, 2008 at Argonne of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne

Pennycook, Steve

316

X-ray spectra transmitted through Compton-thick absorbers  

E-Print Network (OSTI)

X-ray spectra transmitted through matter which is optically thick to Compton scattering are computed by means of Monte Carlo simulations. Applications to the BeppoSAX data of the Seyfert 2 galaxy in Circinus, and to the spectral modeling of the Cosmic X-ray Background, are discussed.

Giorgio Matt; Fulvio Pompilio; Fabio La Franca

1999-04-24T23:59:59.000Z

317

Laser Copper Plasma X-ray Source Debris Characterization  

E-Print Network (OSTI)

Laser Copper Plasma X-ray Source Debris Characterization A Thesis Presented by David Hurley 3, 2007 Vice President for Research and Dean of Graduate studies #12;Abstract Laser copper plasma for x-ray lithography. Copper debris in the form of vapor, ions, dust, and high-speed particles

Huston, Dryver R.

318

Millisecond oscillations during thermonuclear X-ray bursts  

E-Print Network (OSTI)

I analyze 68 oscillation trains detected in a search of 159 thermonuclear bursts from eight neutron star X-ray binaries observed with the Rossi X-ray Timing Explorer. I use all data that were public as of September 2001. ...

Muno, Michael Patrick, 1975-

2002-01-01T23:59:59.000Z

319

X rays following the alpha decay of Pa231  

Science Journals Connector (OSTI)

More detailed information is presented concerning the L and K x-ray spectra due to internal conversion of the electromagnetic transitions following the ? decay of Pa231. Some of the difficulties discussed in Ref. 1 are clarified by the new results.[RADIOACTIVITY Pa231; measured L and K Ac x-ray components, ?? and ?XL coin Ac227 deduced levels, ICC.

A. G. de Pinho; L. T. Auler; A. G. da Silva

1974-05-01T23:59:59.000Z

320

Probing Spatial, Electronic Structures with X-ray Scattering, Spectroscopic  

NLE Websites -- All DOE Office Websites (Extended Search)

Probing Spatial, Electronic Structures with X-ray Scattering, Spectroscopic 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 determine structures due to their incapability to crystallize or change of configuration during crystallization. In this talk, I will present the application of X-ray reflectivity and a newly developed fluctuation X-ray scattering technique to study the structures of lipid membranes and randomly oriented nanoparticles. Three different types of domain registrations occurring with

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Resonant Soft X-Ray Scattering - Combining Structural with Spectroscopic  

NLE Websites -- All DOE Office Websites (Extended Search)

Resonant Soft X-Ray Scattering - Combining Structural with Spectroscopic Resonant Soft X-Ray Scattering - Combining Structural with Spectroscopic Refinement Friday, September 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 of materials. Resonant absorption edges in the soft x-ray regime are especially interesting as they allow the study of the lighter elements, such as in organic or organo-metallic substances, as well as important L-edges of the 3d transition metals important in magnetic and oxide systems. Measurements of soft x-ray absorption spectra are inherently surface sensitive, and are plagued by issues such as extinction (in electron yield measurements) or self absorption (in fluorescence yield

322

Incoherent x-ray scattering in single molecule imaging  

E-Print Network (OSTI)

Imaging of the structure of single proteins or other biomolecules with atomic resolution would be enormously beneficial to structural biology. X-ray free-electron lasers generate highly intense and ultrashort x-ray pulses, providing a route towards imaging of single molecules with atomic resolution. The information on molecular structure is encoded in the coherent x-ray scattering signal. In contrast to crystallography there are no Bragg reflections in single molecule imaging, which means the coherent scattering is not enhanced. Consequently, a background signal from incoherent scattering deteriorates the quality of the coherent scattering signal. This background signal cannot be easily eliminated because the spectrum of incoherently scattered photons cannot be resolved by usual scattering detectors. We present an ab initio study of incoherent x-ray scattering from individual carbon atoms, including the electronic radiation damage caused by a highly intense x-ray pulse. We find that the coherent scattering pa...

Slowik, Jan Malte; Dixit, Gopal; Jurek, Zoltan; Santra, Robin

2014-01-01T23:59:59.000Z

323

Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism  

NLE Websites -- All DOE Office Websites (Extended Search)

Unexpected Angular Dependence of 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 linear dichroism (XMLD) are not only determined by the relative orientation of magnetic moments and x-ray polarization, but their orientation relative to the crystallographic axes must be taken into account for accurate interpretation of XMLD data. Magnetism and X Rays

324

X-ray Emission from Massive StarsX-ray Emission from Massive Stars David CohenDavid Cohen  

E-Print Network (OSTI)

X-ray Emission from Massive StarsX-ray Emission from Massive Stars David CohenDavid Cohen/s)Velocity (km/s) #12;absorption emission emission occulted emission emission UV telescope side side front back #12;absorption emission emission occulted emission emission UV telescope side side front back #12;The

Cohen, David

325

The X-Ray Microcalorimeter Spectrometer for the International X-Ray Observatory  

SciTech Connect

The International X-Ray Observatory (IXO) is under formulation by NASA, ESA and JAXA for deployment in 2022. IXO emerged over the last 18 months as the NASA Constellation-X and ESA/JAXA X-Ray Evolving Universe Spectrometer (XEUS) missions were combined. The driving performance requirements for the X-Ray Microcalorimeter Spectrometer (XMS) are a spectral resolution of 2.5 eV over the central 2'x2' in the 0.3-7.0 keV band, and 10 eV to the edge of the 5'x5' field of view (FOV). The XMS is now based on a microcalorimeter array of Transition-Edge Sensor (TES) thermometers with Au/Bi absorbers and a SQUID MUX readout. One of the concepts studied as part of the mission formulation has a core 40x40 array corresponding to a 2'x2' FOV with 3'' pixels surrounded by an outer, annular 52x52 array of 6'' pixels that extends the field of view to 5.4'x5.4' with better than 10 eV resolution. There are several options for implementing the readout and cooling system of the XMS under study in the US, Europe and Japan. The ADR system will have from two to five stages depending on the performance of the cryocooler. Mechanical coolers with sufficient cooling power at 4K are available now, and {approx}2K coolers are under development. In this paper we give an overview of the XMS instrument, and some of the tradeoffs to be addressed for this observatory instrument.

Kelley, R. L.; Bandler, S. R.; Kilbourne, C. A.; Porter, F. S.; Shirron, P.; Smith, S. J.; Whitehouse, P. [NASA/Goddard Space Flight Center, Greenbelt, MD (United States); Doriese, W. B.; Irwin, K. [National Institute of Standards and Technology, Boulder, CO (United States); Ezoe, Y.; Ishisaki, Y.; Ohashi, T. [Tokyo Metropolitan University, Hachioji, Tokyo (Japan); Fujimoto, R.; Sato, K. [Faculty of Mathematics and Physics, Kanazawa University, Kanazawa (Japan); Gottardi, L.; Hartog, R. den; Herder, J.-W. den; Hoevers, H.; Korte, P. de; Kuur, J. van der [SRON Netherlands Institute for Space Research, Utrecht (Netherlands)] (and others)

2009-12-16T23:59:59.000Z

326

SOFT X-RAY EMISSIONS FROM PLANETS, MOONS, AND COMETS A. Bhardwaj(1)  

E-Print Network (OSTI)

SOFT X-RAY EMISSIONS FROM PLANETS, MOONS, AND COMETS A. Bhardwaj(1) , G. R. Gladstone(2) , R. F to radiate in the soft x-ray energy ( the generation of soft x-rays from these objects, whereas in the hard x-ray energy range (>10 keV) x-rays mainly

Johnson, Robert E.

327

X-ray-induced phase transformation in congruent and vapor-transport-equilibrated lithium tantalate  

E-Print Network (OSTI)

X-ray-induced phase transformation in congruent and vapor-transport-equilibrated lithium tantalate an effect of a partially reversible x-ray-induced increase of diffuse x-ray scattering in both congruent been attributed to x-ray-induced decay of the ferroelectric phase at room temperature. The x-ray

Byer, Robert L.

328

A Hard X-ray View of Accreting X-ray Binary Pulsars  

E-Print Network (OSTI)

The study of the hard (E>10 keV) energy spectra of X-ray binary pulsars can give a wealth of information on the physical processes that occur close to the neutron star surface. Extreme matter regimes are probed, and precious information on how matter and radiation behave and interact in critical conditions can be obtained. We will give an overview on the most recent results obtained by RXTE and BeppoSAX on this class of objects, in order to pass the baton onto just launched experiments, like INTEGRAL, or soon to be launched, like AGILE and ASTRO-E2.

Mauro Orlandini

2004-02-26T23:59:59.000Z

329

Apparatus for generating x-ray holograms  

DOE Patents (OSTI)

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.

Rhodes, Charles K. (Chicago, IL); Boyer, Keith (Los Alamos, NM); Solem, Johndale C. (Los Alamos, NM); Haddad, Waleed S. (Chicago, IL)

1990-01-01T23:59:59.000Z

330

Apparatus for generating x-ray holograms  

DOE Patents (OSTI)

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.

Rhodes, C.K.; Boyer, K.; Solem, J.C.; Haddad, W.S.

1990-09-11T23:59:59.000Z

331

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray 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 advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

332

Femtosecond Time-Delay X-ray Holography  

NLE Websites -- All DOE Office Websites (Extended Search)

Time-Delay X-ray Holography 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 penetration into materials and the ability to probe structure at and below the nanometer scale. Their ultra-short duration gives information about this structure at the fundamental time-scales of atoms and molecules. The extreme intensity of the pulses will allow this information to be acquired in a single shot, so that these studies can be carried out on non-repeatable processes or on weakly-scattering objects that will be modified by the pulse. A fourth property of XFEL pulses is their high transverse coherence, which brings the promise of decades of innovation in visible optics to the X-ray regime, such as holography, interferometry, and laser-based imaging. Making an effective use of XFEL pulses, however, will benefit from innovations that are new to both X-ray science and coherent optics. One such innovation is the new method of time-delay X-ray holography [i], recently demonstrated at the FLASH FEL at DESY in Hamburg, to measure the evolution of objects irradiated by intense pulses.

333

X-ray Crystallographic Center (XCC) User Registration Form Peter Y. Zavalij X-ray Crystallographi Center 091 Chemistry Bldg. / College Park, MD 20742  

E-Print Network (OSTI)

X-ray Crystallographic Center (XCC) User Registration Form Peter Y. Zavalij X-ray Crystallographi. or advisor confirmation e-mail X-ray Diffractometer that will be used: User Level and Status Smart Apex2X'Pert Pro MRD (Reflectivity & low angles) Xeuss (Small/Wide Angle X-ray Scattering) Submitting user ­ only

Thirumalai, Devarajan

334

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

E-Print Network (OSTI)

Lunar X-ray fluorescence observations by the Chandrayaan-1 X-ray Spectrometer (C1XS): Results from Spectroscopy a b s t r a c t The Chandrayaan-1 X-ray Spectrometer (C1XS) flown on-board the first Indian lunar mission Chan- drayaan-1, measured X-ray fluorescence spectra during several episodes of solar flares

Wieczorek, Mark

335

National Ignition Facility core x-ray streak camera  

SciTech Connect

The National Ignition Facility (NIF) core x-ray streak camera will be used for laser performance verification experiments as well as a wide range of physics experiments in the areas of high-energy-density science, inertial confinement fusion, and basic science. The x-ray streak camera system is being designed to record time-dependent x-ray emission from NIF targets using an interchangeable family of snouts for measurements such as one-dimensional (1D) spatial imaging or spectroscopy. the NIF core x-ray streak camera will consist of an x-ray-sensitive photocathode that detects x rays with 1D spatial resolution coupled to an electron streak tube to detect a continuous time history of the x rays incident on the photocathode over selected time periods. A charge-coupled-device (CCD) readout will record the signal from the streak tube. The streak tube, CCD, and associated electronics will reside in an electromagnetic interference, and electromagnetic pulse protected, hermetically sealed, temperature-controlled box whose internal pressure is approximately 1 atm. The streak tube itself will penetrate through the wall of the box into the target chamber vacuum. We are working with a goal of a spatial resolution of 15 lp/mm with 50% contrast transfer function at the photocathode and adjustment sweep intervals of 1--50 ns. The camera spectral sensitivity extends from soft x rays to 20 keV x rays, with varying quantum efficiency based on photocathode selection. The system will have remote control, monitoring, and Ethernet communications through an embedded controller. The core streak camera will be compatible with the instrument manipulators at the OMEGA (University of Rochester) and NIF facilities.

Kimbrough, J. R.; Bell, P. M.; Christianson, G. B.; Lee, F. D.; Kalantar, D. H.; Perry, T. S.; Sewall, N. R.; Wootton, A. J.

2001-01-01T23:59:59.000Z

336

The radiation-tolerant x-ray monitor  

SciTech Connect

A vacuum photoelectric detector (monitor) (VPD) designed for plasma tomography, megnetohydrodynamics monitoring, and imaging with the help of thermal x-ray radiation on the ITER facility is described. Laboratory experiments demonstrate that VPD has high sensitivity to thermal x rays and low sensitivity to hard gamma rays and neutrons. The results of tests of a prototype of this monitor on a {sup 60}Co source of gamma rays, on nuclear reactor and its calibration using radiation from an x-ray tube, and tests of its serviceability on the T-10 facility are presented.

Gott, Yu. V.; Stepanenko, M. M. [Nuclear Fusion Institute, Russian Research Center 'Kurchatov Institute', Kurchatov Sq. 1, Moscow 123182 (Russian Federation)

2008-10-15T23:59:59.000Z

337

X-ray backscatter imaging of nuclear materials  

DOE Patents (OSTI)

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.

Chapman, Jeffrey Allen; Gunning, John E; Hollenbach, Daniel F; Ott, Larry J; Shedlock, Daniel

2014-09-30T23:59:59.000Z

338

Cryogenic X-Ray Diffraction Microscopy for Biological Samples  

Science Journals Connector (OSTI)

X-ray diffraction microscopy (XDM) is well suited for nondestructive, high-resolution biological imaging, especially for thick samples, with the high penetration power of x rays and without limitations imposed by a lens. We developed nonvacuum, cryogenic (cryo-) XDM with hard x rays at 8 keV and report the first frozen-hydrated imaging by XDM. By preserving samples in amorphous ice, the risk of artifacts associated with dehydration or chemical fixation is avoided, ensuring the imaging condition closest to their natural state. The reconstruction shows internal structures of intact D. radiodurans bacteria in their natural contrast.

Enju Lima; Lutz Wiegart; Petra Pernot; Malcolm Howells; Joanna Timmins; Federico Zontone; Anders Madsen

2009-11-05T23:59:59.000Z

339

Cryogenic X-ray Diffraction Microscopy for Biological Samples  

SciTech Connect

X-ray diffraction microscopy (XDM) is well suited for nondestructive, high-resolution biological imaging, especially for thick samples, with the high penetration power of x rays and without limitations imposed by a lens. We developed nonvacuum, cryogenic (cryo-) XDM with hard x rays at 8 keV and report the first frozen-hydrated imaging by XDM. By preserving samples in amorphous ice, the risk of artifacts associated with dehydration or chemical fixation is avoided, ensuring the imaging condition closest to their natural state. The reconstruction shows internal structures of intact D. radiodurans bacteria in their natural contrast.

E Lima; L Wiegart; P Pernot; M Howells; J Timmins; F Zontone; A Madsen

2011-12-31T23:59:59.000Z

340

X-Ray Afterglows from Gamma-Ray Bursts  

Science Journals Connector (OSTI)

We consider possible interpretations of the recently detected X-ray afterglow from the gamma-ray burst source GRB 970228. Cosmological and Galactic models of gamma-ray bursts predict different flux and spectral evolution of X-ray afterglows. We show that models based on adiabatic expansion of relativistic forward shocks require very efficient particle energization or postburst reacceleration during the expansion. Cooling neutron star models predict a very distinctive spectral and flux evolution that can be tested in current X-ray data.

M. Tavani

1997-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Current Problems for X-ray Emission from Radio Jets  

E-Print Network (OSTI)

A list is presented of known extragalactic radio jets which also have associated X-ray emission. The canonical emission processes for the production of X-rays are reviewed and the sources are categorized on the basis of our current understanding. Although it seems clear that the X-ray emission is non-thermal, the two competing processes, synchrotron and inverse Compton emissions, arise from extremely high energy (synchrotron) or extremely low energy (beaming models with IC emission), relativistic electrons. Only synchrotron self-Compton emission from a few hotspots provides information on the `normal' energy range of the electrons responsible for the observed radio emission.

D. E. Harris

2000-12-17T23:59:59.000Z

342

Dynamic model of anisotropic x-ray refraction  

Science Journals Connector (OSTI)

General mechanisms of anisotropic x-ray refraction at the resonance energy are investigated on the basis of dynamic-scattering theory. The deductions show that x rays within the crystals that have anisotropic susceptibility are completely polarized and have two elliptical polarization states. Analytical expressions of the elliptical axes, refractive indices, and absorption coefficients for these two types of polarized waves are obtained in terms of the anisotropic components of the susceptibility tensor. Anisotropic birefringence and dichroism effects associated with the polarization properties of the x-ray waves are also illustrated theoretically.

X. R. Huang, Yong Li, W. J. Liu, and S. S. Jiang

1997-11-01T23:59:59.000Z

343

X-Ray Directional Dichroism of a Polar Ferrimagnet  

Science Journals Connector (OSTI)

In a polar ferrimagnet GaFeO3, we have found a novel magneto-optical effect, termed x-ray nonreciprocal directional dichroism (XNDD), that the x-ray absorption at around the K edge of an Fe ion depends on whether the x-ray propagation vector is parallel or antiparallel to the outer product of the magnetization and electric-polarization vectors. The XNDD spectroscopy as demonstrated here can be a useful tool to probe the local magnetism in noncentrosymmetric systems such as magnetic interfaces and nanostructures.

M. Kubota, T. Arima, Y. Kaneko, J. P. He, X. Z. Yu, and Y. Tokura

2004-03-29T23:59:59.000Z

344

Characterization of X-ray generator beam profiles.  

SciTech Connect

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.

Mitchell, Dean J; Harding, Lee T.; Thoreson, Gregory G.; Theisen, Lisa Anne; Parmeter, John Ethan; Thompson, Kyle Richard

2013-07-01T23:59:59.000Z

345

Spatiotemporal focusing dynamics in plasmas at X-ray wavelength  

SciTech Connect

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.

Sharma, A., E-mail: a-physics2001@yahoo.com; Tibai, Z. [Institute of Physics, University of Pecs, Pecs–7624 (Hungary)] [Institute of Physics, University of Pecs, Pecs–7624 (Hungary); Hebling, J. [Institute of Physics, University of Pecs, Pecs–7624 (Hungary) [Institute of Physics, University of Pecs, Pecs–7624 (Hungary); Szentagothai Research Centre, University of Pecs, Pecs-7624 (Hungary); Mishra, S. K. [Institute for Plasma Research, Gandhinagar (India)] [Institute for Plasma Research, Gandhinagar (India)

2014-03-15T23:59:59.000Z

346

Soft x-ray resist characterization: Studies with a laser plasma x-ray source  

SciTech Connect

Little work has been performed to characterize the exposure sensitivity, contrast, and tone of candidate resists for photon energies between 100--300 eV, the range in which projection soft x-ray lithography will be developed. We report here the characterization of near-edge x-ray absorption fine structure (NEXAFS) spectra, exposure sensitivity, contrast, and post-exposure processing of selected polysilane resists at photon energies close to the Si L{sub 2,3} absorption edge (100 eV). We find absorption resonance features in the NEXAFS spectra which we assign to excitation into Si--Si and Si--C {sigma}* orbitals. Using monochromatized XUV exposures on the Si--Si {sigma}* resonance at 105 eV, followed by solvent dissolution development, we have measured the exposure sensitivity curves of these resists. We find sensitivities in the range of 600--3000 mJ/cm{sup 2} and contrasts in the range from 0.5--1.4, depending on the polysilane side chain. We have also performed exposure sensitivity measurements at 92 eV, below the edge. Sensitivity decreases slightly compared to 105 eV exposures and the saturation depth and contrast both increase, as expected. We find also that exposing resist films to oxygen after XUV exposure, but before development increases the sensitivity markedly. 7 figs.

Kubiak, G.D.; Outka, D.A. (Sandia National Labs., Livermore, CA (USA)); Zeigler, J.M. (Sandia National Labs., Albuquerque, NM (USA))

1990-01-01T23:59:59.000Z

347

Thermonuclear (Type I) X-Ray Bursts Observed by the Rossi X-Ray Timing Explorer  

Science Journals Connector (OSTI)

We have assembled a sample of 1187 thermonuclear (type I) X-ray bursts from observations of 48 accreting neutron stars by the Rossi X-ray Timing Explorer, spanning more than 10 years. The sample contains examples of two of the three theoretical ignition regimes (confirmed via comparisons with numerical models) and likely examples of the third. We present a detailed analysis of the variation of the burst profiles, energetics, recurrence times, presence of photospheric radius expansion, and presence of burst oscillations, as a function of accretion rate. We estimated the distance for 35 sources exhibiting radius-expansion bursts, and found that the peak flux of such bursts varies typically by 13%. We classified sources into two main groups based on the burst properties: (1) both long and short bursts (indicating mixed H/He accretion), and (2) consistently short bursts (primarily He accretion), and we calculated the mean burst rate as a function of accretion rate for the two groups. The decrease in burst rate observed at > 0.06Edd$0.06˙{M}Edd$ --> ( -->2 ? 1037 ergs s?1) is associated with a transition in the persistent spectral state and (as has been suggested previously) may be related to the increasing role of steady He burning. We found many examples of bursts with recurrence times

Duncan K. Galloway; Michael P. Muno; Jacob M. Hartman; Dimitrios Psaltis; Deepto Chakrabarty

2008-01-01T23:59:59.000Z

348

A Laboratory-based Hard X-ray Monochromator for High-Resolution X-ray Emission Spectroscopy and X-ray Absorption Near Edge Structure Measurements  

E-Print Network (OSTI)

We report the development of a laboratory-based Rowland-circle monochromator that incorporates a low poer x-ray (bremsstrahlung) tube source, a spherically-bent crystal analyzer (SBCA), 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 dmeonstrating 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 (XES) comparable to those achived at monochromatized spectroscopy beamlines at synchrotron light sources. For x-ray absorption near edge structure (XANES), 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-powered line-foc...

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

2014-01-01T23:59:59.000Z

349

Synchrotron-Radiation Induced X-Ray Emission (SRIXE)  

SciTech Connect

Elemental analysis using emission of characteristic x rays is a well-established scientific method. The success of this analytical method is highly dependent on the properties of the source used to produce the x rays. X-ray tubes have long existed as a principal excitation source, but electron and proton beams have also been employed extensively. The development of the synchrotron radiation x-ray source that has taken place during the past 40 years has had a major impact on the general field of x-ray analysis. Even tier 40 years, science of x-ray analysis with synchrotron x-ray beams is by no means mature. Improvements being made to existing synchrotron facilities and the design and construction of new facilities promise to accelerate the development of the general scientific use of synchrotron x-ray sources for at least the next ten years. The effective use of the synchrotron source technology depends heavily on the use of high-performance computers for analysis and theoretical interpretation of the experimental data. Fortunately, computer technology has advanced at least as rapidly as the x-ray technology during the past 40 years and should continue to do so during the next decade. The combination of these technologies should bring about dramatic advances in many fields where synchrotron x-ray science is applied. It is interesting also to compare the growth and rate of acceptance of this particular research endeavor to the rates for other technological endeavors. Griibler [1997] cataloged the time required for introduction, diffusion,and acceptance of technological, economic, and social change and found mean values of 40 to 50 years. The introduction of the synchrotron source depends on both technical and non-technical factors, and the time scale at which this seems to be occurring is quite compatible with what is seen for other major innovations such as the railroad or the telegraph. It will be interesting to see how long the present rate of technological change and increase in scientific use can be maintained for the synchrotron x-ray source. A short summary of the present state of the synchrotron radiation-induced x-ray emission (SRIXE) method is presented here. Basically, SRIXE experiments can include any that depend on the detection. of characteristic x-rays produced by the incident x-ray beam born the synchrotron source as they interact with a sample. Thus, experiments done to measure elemental composition, chemical state, crystal, structure, and other sample parameters can be considered in a discussion of SRIXE. It is also clear that the experimentalist may well wish to use a variety of complementary techniques for study of a given sample. For this reason, discussion of computed microtomography (CMT) and x-ray diffraction is included here. It is hoped that this present discussion will serve as a succinct introduction to the basic ideas of SRIXE for those not working in the field and possibly help to stimulate new types of work by those starting in the field as well as by experienced practitioners of the art. The topics covered include short descriptions of (1) the properties of synchrotron radiation, (2) a description of facilities used for its production, (3) collimated microprobe, (4) focused microprobes, (5) continuum and monoenergetic excitation, (6) detection limits, (7) quantitation, (8) applications of SRIXE, (9) computed microtomography (CMT), and (10)chemical speciation using x-ray absorption near-edge structure (XANES) and extended x-ray absorption fine structure (EXAFS). An effort has been made to cite a wide variety of work from different laboratories to show the vital nature of the field.

Jones, Keith W.

1999-09-01T23:59:59.000Z

350

E-Print Network 3.0 - airborne lead x-ray Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

Pulsars... you'd . . . Active Galactic . . . X-ray binaries Pulsars and relatives Gamma-ray bursts Gravitational... 1 - Type 2 X-ray binaries - Low mass X-ray binaries (LMXBs)...

351

E-Print Network 3.0 - advanced x-ray timing Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

AND COMETS: RELATIONSHIP WITH SOLAR X-RAYS AND SOLAR WIND Summary: with the occurrence of solar X-ray flare, when light travel time delay is accounted, suggesting that X-rays...

352

X-RAY ABSORPTION STUDIES OF GRAPHITE INTERCALATES AND METAL-AMMONIA SOLUTION  

E-Print Network (OSTI)

I. INTRODUCTION A. X-Ray Absorption Spectroscopy B. Graphiteacknowledged. The X-Ray absorption data could not have beenI INTRODUCTION X-ray absorption, spectroscopy (XAS) has been

Robertson, A.S.

2010-01-01T23:59:59.000Z

353

AN X-RAY ABSORPTION SPECTROSCOPY STUDY OF MANGANESE CONTAINING COMPOUNDS AND PHOTOSYNTHETIC SPINACH CHLOROPLASTS  

E-Print Network (OSTI)

II. Extended X-ray Absorption Fine Structure (EXAFS) TheoryIII. X-ray Absorption Spectroscopy (XAS) ExperimentIII. EXTENDED X-RAY ABSORPTION FINE STRUCTURE (EXAFS) DATA

Kirby, Jon Allan

2012-01-01T23:59:59.000Z

354

X-ray Absorption Spectroscopy Study of Prototype Chemical Systems: Theory vs. Experiment  

E-Print Network (OSTI)

acids by Near Edge X-ray Absorption Fine Structure (NEXAFS)X-ray Absorption Spectroscopy Study of Prototype ChemicalGlaeser Spring 2010 X-ray Absorption Spectroscopy Study of

Schwartz, Craig Philip

2010-01-01T23:59:59.000Z

355

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

E-Print Network (OSTI)

X-ray absorption spectroscopy at the Ni–K edge inin vivo by micro x-ray absorption spectroscopy (XAS) at theNi–K edge. Both x-ray absorption near edge structure and

Kachenko, A.

2009-01-01T23:59:59.000Z

356

Materials Applications of Photoelectron Emission Microscopy....  

NLE Websites -- All DOE Office Websites (Extended Search)

Applications of Photoelectron Emission Microscopy. Materials Applications of Photoelectron Emission Microscopy. Abstract: Photoelectron emission microscopy (PEEM) is a versatile...

357

Definition: Portable X-Ray Diffraction (XRD) | Open Energy Information  

Open Energy Info (EERE)

Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Portable X-Ray Diffraction (XRD) Jump to: navigation, search Dictionary.png Portable X-Ray Diffraction (XRD) Portable X-Ray Diffraction (XRD) is a field-based technique that can be used for identification of crystalline materials and analysis of unit cell dimensions. Portable XRD analysis is similar to X-ray powder diffraction, which has traditionally been used in geology, environmental science, material science, and engineering to rapidly identify unknown crystalline substances. Portable XRD analysis allows for simpler sample preparation, faster analytical times than traditional methods (less than 2 minutes), and can be performed at the sampling site in the field. A pure, finely ground

358

Plasma debris sputter resistant x-ray mirror  

Science Journals Connector (OSTI)

A diamond-like carbon (DLC) mirror, used as a grazing incident mirror in a plasma x-ray source, exhibits a high resistance to plasma debris sputtering. Good mirror reflectivity at a...

Amano, Sho; Inoue, Tomoaki; Harada, Tetsuo

2013-01-01T23:59:59.000Z

359

New Directions in X-ray Scattering - SSRL  

NLE Websites -- All DOE Office Websites (Extended Search)

6, 2006 A summary of the workshop on New Directions in X-ray Scattering On Dec 6th, we held a day long workshop to solicit user input on the new directions that the SSRL...

360

Synchroton X-Ray Studies of Liquid-Vapor Interfaces  

Science Journals Connector (OSTI)

The variation of density across the liquid-vapor interface from essentially zero density far out in the vapor phase to a homogeneous density deep in the liquid phase can be determined by X-ray reflectivity mea...

J. Als-Nielsen

1988-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Energy weighted x-ray dark-field imaging  

Science Journals Connector (OSTI)

The dark-field image obtained in grating-based x-ray phase-contrast imaging can provide information about the objects’ microstructures on a scale smaller than the pixel size...

Pelzer, Georg; Zang, Andrea; Anton, Gisela; Bayer, Florian; Horn, Florian; Kraus, Manuel; Rieger, Jens; Ritter, Andre; Wandner, Johannes; Weber, Thomas; Fauler, Alex; Fiederle, Michael; Wong, Winnie S; Campbell, Michael; Meiser, Jan; Meyer, Pascal; Mohr, Jürgen; Michel, Thilo

2014-01-01T23:59:59.000Z

362

Magnetic fields of neutron stars in X-ray binaries  

E-Print Network (OSTI)

A substantial fraction of the known neutron stars resides in X-ray binaries -- systems in which one compact object accretes matter from a companion star. Neutron stars in X-ray binaries have magnetic fields among the highest found in the Universe, spanning at least the range from $\\sim10^8$ to several 10$^{13}$ G. The magnetospheres around these neutron stars have a strong influence on the accretion process, which powers most of their emission. The magnetic field intensity and geometry, are among the main factors responsible for the large variety of spectral and timing properties observed in the X-ray energy range, making these objects unique laboratories to study the matter behavior and the radiation processes in magnetic fields unaccessible on Earth. In this paper we review the main observational aspects related to the presence of magnetic fields in neutron star X-ray binaries and some methods that are used to estimate their strength.

Revnivtsev, Mikhail

2014-01-01T23:59:59.000Z

363

X-ray emission from the terrestrial magnetosheath  

E-Print Network (OSTI)

[1] X-rays are generated throughout the terrestrial magnetosheath as a consequence of charge transfer collisions between heavy solar wind ions and geocoronal neutrals. The solar wind ions resulting from these collisions ...

Robertson, Ina Picket; Cravens, Thomas Edward

2003-04-29T23:59:59.000Z

364

Lensless Imaging of Magnetic Nanostructures by X-ray Spectro...  

NLE Websites -- All DOE Office Websites (Extended Search)

co-workers. Their implementation of the technique is an extension of lensless Fourier transform holography to the x-ray regime, which detects the far field diffraction pattern of a...

365

Polarization Entangled Photons at X-Ray Energies  

E-Print Network (OSTI)

We show that polarization entangled photons at x-ray energies can be generated via spontaneous parametric down conversion. Each of the four Bell states can be generated by choosing the angle of incidence and polarization of the pumping beam.

S. Shwartz; S. E. Harris

2010-12-16T23:59:59.000Z

366

Towards hard x-ray imaging at GHz frame rate  

SciTech Connect

Gigahertz (GHz) imaging using hard x-rays ( Greater-Than-Or-Equivalent-To 10 keV) can be useful to high-temperature plasma experiments, as well as research and applications using coherent photons from synchrotron radiation and x-ray free electron lasers. GHz framing rate can be achieved by using multiple cameras through multiplexing. The advantages and trade-offs of single-photon detection mode, when no more than one x-ray photon is detected per pixel, are given. Two possible paths towards x-ray imaging at GHz frame rates using a single camera are: (a) avalanche photodiode arrays of high-Z materials and (b) microchannel plate photomultipliers in conjunction with materials with large indices of refraction.

Wang Zhehui; Morris, C. L.; Kapustinsky, J. S.; Kwiatkowski, K.; Luo, S.-N. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2012-10-15T23:59:59.000Z

367

Towards hard X-ray imaging at GHz frame rate  

SciTech Connect

Gigahertz (GHz) imaging using hard X-rays ({approx}> 10 keV) can be useful to high-temperature plasma experiments, as well as research using coherent photons from synchrotron radiation and X-ray free electron lasers. GHz framing rate can be achieved by using multiple cameras through multiplexing. The advantages and trade-offs of single-photon detection mode, when no more than one X-ray photon is detected per pixel, are given. Two possible paths towards X-ray imaging at GHz frame rates using a single camera are (a) Avalanche photodiode arrays of high-Z materials and (b) Microchannel plate photomultipliers in conjunction with materials with large indices of refraction.

Wang, Zhehui [Los Alamos National Laboratory; Morris, Christopher [Los Alamos National Laboratory; Luo, Shengnian [Los Alamos National Laboratory; Kwiatkowski, Kris K. [Los Alamos National Laboratory; Kapustinsky, Jon S. [Los Alamos National Laboratory

2012-05-02T23:59:59.000Z

368

Magnetism studies using resonant, coherent, x-ray scattering...  

NLE Websites -- All DOE Office Websites (Extended Search)

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...

369

Copyright The Discussion Group of X-Ray Analysis,  

E-Print Network (OSTI)

-2900. 3 In Situ Spatial and Time-Resolved Studies of Electrochemical Reactions by Scanning Transmission X the Signal-to-Noise Ratio of X-ray Diffraction Profiles by Smoothed Principal Component Analysis Zeng Ping

Jun, Kawai

370

X-Ray Astronomy to Resonant Theranostics for Cancer Treatment  

E-Print Network (OSTI)

X-Ray Astronomy to Resonant Theranostics for Cancer Treatment Sultana N. Nahar Department-Plasma Theranostics or RNPT, which gives indication for one most efficient way for destruction of malignant cells. 1

Nahar, Sultana Nurun

371

Vitreous carbon mask substrate for X-ray lithography  

DOE Patents (OSTI)

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.

Aigeldinger, Georg (Livermore, CA); Skala, Dawn M. (Fremont, CA); Griffiths, Stewart K. (Livermore, CA); Talin, Albert Alec (Livermore, CA); Losey, Matthew W. (Livermore, CA); Yang, Chu-Yeu Peter (Dublin, CA)

2009-10-27T23:59:59.000Z

372

Optical and X-ray Variability of AGNs  

E-Print Network (OSTI)

I present new comparisons of AGN optical, UV, and X-ray variations. These reveal complex relationships between the different passbands that can change with time in a given object. While there is evidence from several objects that X-ray and optical activity levels are correlated on long timescales, variations on shorter timescales can occur independently. It is proposed that the combination of correlated and uncorrelated short-timescale variability is a consequence of anisotropic high-energy emission. It is also argued that the correlation between X-ray and optical variability on long timescales must be due to a common underlying factor and not to reprocessing of X-ray radiation.

C. Martin Gaskell

2006-12-30T23:59:59.000Z

373

,~ Abstract Submitted to 1997 Denver X-Ray Conference  

E-Print Network (OSTI)

,~ Abstract Submitted to 1997 Denver X-Ray Conference Denver, Colorado -August 4-8, 1997 BNL-.64346 being distributed through the entire volume of the particle needs further investigation. *Work supported

Brookhaven National Laboratory

374

Photon Sciences | Beamlines | SRX: Submicron Resolution X-ray Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

SRX: Submicron Resolution X-ray Spectroscopy SRX: Submicron Resolution X-ray Spectroscopy Poster | Fact Sheet | Preliminary Design Report Scientific Scope Scientific communities such as environmental sciences, life sciences, and material sciences have identified the need to develop analytical resources to advance the understanding of complex natural and engineered systems that are heterogeneous on the micron to nanometer scale. These needs for high intensity x-ray nanoprobes resulted in the commitment of the NSLS-II Project to build the Submicron Resolution X-ray (SRX) Spectroscopy beamline showing a unique combination of high spectral resolution over a very broad energy range and very high beam intensity in a sub-micrometer spot. NSLS-II will provide one of the best sources in the world for such an instrument.

375

X-ray Raman scattering study of aligned polyfluorene  

E-Print Network (OSTI)

We present a non-resonant inelastic x-ray scattering study at the carbon K-edge on aligned poly[9,9-bis(2-ethylhexyl)-fluorene-2,7-diyl] and show that the x-ray Raman scattering technique can be used as a practical alternative to x-ray absorption measurements. We demonstrate that this novel method can be applied to studies on aligned $\\pi$-conjugated polymers complementing diffraction and optical studies. Combining the experimental data and a very recently proposed theoretical scheme we demonstrate a unique property of x-ray Raman scattering by performing the symmetry decomposition on the density of unoccupied electronic states into $s$- and $p$-type symmetry contributions.

S. Galambosi; M. Knaapila; J. A. Soininen; K. Nyg\\aard; S. Huotari; F. Galbrecht; U. Scherf; A. P. Monkman; K. Hämäläinen

2006-08-29T23:59:59.000Z

376

Gravitational and Relativistic Deflection of X-Ray Superradiance  

E-Print Network (OSTI)

Exploring Einstein's theories of relativity in quantum systems, for example by using atomic clocks at high speeds can deepen our knowledge in physics. However, many challenges still remain on finding novel methods for detecting effects of gravity and of special relativity and their roles in light-matter interaction. Here we introduce a scheme of x-ray quantum optics that allows for a millimeter scale investigation of the relativistic redshift by directly probing a fixed nuclear crystal in Earth's gravitational field with x-rays. Alternatively, a compact rotating crystal can be used to force interacting x-rays to experience inhomogeneous clock tick rates in a crystal. We find that an association of gravitational or special-relativistic time dilation with quantum interference will be manifested by deflections of x-ray photons. Our protocol suggests a new and feasible tabletop solution for probing effects of gravity and special relativity in the quantum world.

Wen-Te Liao; Sven Ahrens

2014-11-27T23:59:59.000Z

377

High performance x-ray anti-scatter grid  

DOE Patents (OSTI)

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.

Logan, C.M.

1995-05-23T23:59:59.000Z

378

Pixel detectors for x-ray imaging spectroscopy in space  

Science Journals Connector (OSTI)

Pixelated semiconductor detectors for X-ray imaging spectroscopy are foreseen as key components of the payload of various future space missions exploring the x-ray sky. Located on the platform of the new Spectrum-Roentgen-Gamma satellite, the eROSITA (extended Roentgen Survey with an Imaging Telescope Array) instrument will perform an imaging all-sky survey up to an X-ray energy of 10 keV with unprecedented spectral and angular resolution. The instrument will consist of seven parallel oriented mirror modules each having its own pnCCD camera in the focus. The satellite born X-ray observatory SIMBOL-X will be the first mission to use formation-flying techniques to implement an X-ray telescope with an unprecedented focal length of around 20 m. The detector instrumentation consists of separate high- and low energy detectors, a monolithic 128 ? 128 DEPFET macropixel array and a pixellated CdZTe detector respectively, making energy band between 0.5 to 80 keV accessible. A similar concept is proposed for the next generation X-ray observatory IXO. Finally, the MIXS (Mercury Imaging X-ray Spectrometer) instrument on the European Mercury exploration mission BepiColombo will use DEPFET macropixel arrays together with a small X-ray telescope to perform a spatially resolved planetary XRF analysis of Mercury's crust. Here, the mission concepts and their scientific targets are briefly discussed, and the resulting requirements on the detector devices together with the implementation strategies are shown.

J Treis; R Andritschke; R Hartmann; S Herrmann; P Holl; T Lauf; P Lechner; G Lutz; N Meidinger; M Porro; R H Richter; F Schopper; H Soltau; L Strüder

2009-01-01T23:59:59.000Z

379

The Hard X-ray Sky: Recent Observational Progress  

SciTech Connect

The last fifty years have witnessed the birth, development, and maturation to full potential of hard X-ray astrophysics. The primary force driving the history of the field has been the development of space-based instrumentation optimized for getting the maximum science out of observations of high-energy photons from astrophysical sources. Hard X-ray telescopes are leading research in areas such as galactic diffuse emission, galactic transients, and active galactic nuclei.

Gehrels, Neil [NASA/GSFC/ASD/Code 661, Greenbelt, Md 20071 (United States); Cannizzo, John K. [CRESST/UMBC/NASA/GSFC/ASD/Code 661, Greenbelt, Md 20071 (United States)

2009-05-11T23:59:59.000Z

380

The X-ray background and the evolution of AGN  

E-Print Network (OSTI)

We discuss the constraints on the AGN evolution from the cosmic X-ray background and source counts. A synthesis model to fit the X-ray background is presented. In the model, the spectrum of type 2 AGN has been modeled including Compton down--scattering within the absorbing material. Besides, we introduced a dependence on redshift of the relative number of obscured sources and found a decrease of the fraction of type 2 AGN at redshifts larger than 2.

Fulvio Pompilio; Fabio La Franca; Giorgio Matt

1999-09-23T23:59:59.000Z

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Sapphire analyzers for high-resolution x-ray spectroscopy.  

SciTech Connect

We present a sapphire (Al{sub 2}O{sub 3}) analyzer for high-resolution X-ray spectroscopy with 31-meV energy resolution. The analyzer is designed for resonant inelastic X-ray scattering (RIXS) measurements at the CuK{sub a} absorption edge near 8990 eV. The performance of the analyzer is demonstrated by measuring phonon excitations in beryllium because of its known dynamical structure and high counting rates.

Yavas, H.; Alp, E.; Sinn, H.; Alatas, A.; Said, A.; Shvydko, Y.; Toellner, T.; Khachatryan, R.; Billinge, S.; Hasan, Z.; Sturhahn, W.; Michigan State Univ.; Princeton Univ.; DESY

2007-11-11T23:59:59.000Z

382

X-ray tube with magnetic electron steering  

DOE Patents (OSTI)

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.

Reed, Kim W. (Albuquerque, NM); Turman, Bobby N. (Albuquerque, NM); Kaye, Ronald J. (Albuquerque, NM); Schneider, Larry X. (Albuquerque, NM)

2000-01-01T23:59:59.000Z

383

Ris-M-2751 X-Ray Energy Dispersive  

E-Print Network (OSTI)

(PHOT) k«V 50 Risø National Laboratory, DK-4000 Roskilde, Denmark October 1988 #12;Ris*-M-2751 X-ray energy is impinging on the sample (Fig. lb). Its wavelength (photon energy) is in the course of measurements changedm ii. S Risø-M-2751 X-Ray Energy Dispersive Diffraction Lecture Notes Bronislaw Buras BaKo 30 40 E

384

A compact scanning soft X-ray microscope  

SciTech Connect

Soft x-ray microscopes operating at wavelengths between 2.3 nm and 4.4 nm are capable of imaging wet biological cells with a resolution many times that of a visible light microscope. Several such soft x-ray microscopes have been constructed. However, with the exception of contact microscopes, all use synchrotrons as the source of soft x-ray radiation and Fresnel zone plates as the focusing optics. These synchrotron based microscopes are very successful but have the disadvantage of limited access. This dissertation reviews the construction and performance of a compact scanning soft x-ray microscope whose size and accessibility is comparable to that of an electron microscope. The microscope uses a high-brightness laser-produced plasma as the soft x-ray source and normal incidence multilayer-coated mirrors in a Schwarzschild configuration as the focusing optics. The microscope operates at a wavelength of 14 nm, has a spatial resolution of 0.5 {mu}m, and has a soft x-ray photon flux through the focus of 10{sup 4}-10{sup 5} s{sup {minus}1} when operated with only 170 mW of average laser power. The complete system, including the laser, fits on a single 4{prime} x 8{prime} optical table. The significant components of the compact microscope are the laser-produced plasma (LPP) source, the multilayer coatings, and the Schwarzschild objective. These components are reviewed, both with regard to their particular use in the current microscope and with regard to extending the microscope performance to higher resolution, higher speed, and operation at shorter wavelengths. Measurements of soft x-ray emission and debris emission from our present LPP source are presented and considerations given for an optimal LPP source. The LPP source was also used as a broadband soft x-ray source for measurement of normal incidence multilayer mirror reflectance in the 10-25 nm spectral region.

Trail, J.A.

1989-01-01T23:59:59.000Z

385

New Directions in X-Ray Light Sources  

ScienceCinema (OSTI)

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.

Roger Falcone

2010-01-08T23:59:59.000Z

386

X-Ray Diffraction Studies of Copper Nanopowder  

E-Print Network (OSTI)

Copper nanopowder preparation and its X-Ray diffraction studies are reported in this paper. Electrolytic cathode deposition method is simple and cheapest process for its preparation. Copper nanopowder has been prepared from aqueous copper sulphate solution. Wide range of experimental conditions has been adopted in this process and its X-Ray diffraction characterizations have been studied. The results confirming copper nanopowder with size below 30 nm. Uniformed size Copper nanopowder preparation, in normal room temperature is importance of this study.

T. Theivasanthi; M. Alagar

2010-03-31T23:59:59.000Z

387

E-Print Network 3.0 - anomalous small-angle x-ray Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

2008Standard Operating Procedure Title: Small Angle X-ray Scattering... approved: December 26 2009 Small Angle X-ray Scattering, Rotating Anode PURPOSE: This Standard...

388

E-Print Network 3.0 - angle x-ray scattering Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

2008Standard Operating Procedure Title: Small Angle X-ray Scattering... approved: December 26 2009 Small Angle X-ray Scattering, Rotating Anode PURPOSE: This Standard...

389

X-RAY ABSORPTION SPECTROSCOPY FOR THE CHEMICAL CHARACTERIZATION OF ATMOSPHERIC AEROSOLS  

E-Print Network (OSTI)

November 11-16 9 1979 X-RAY ABSORPTION SPECTROSCOPY FOR THEUniversity of California. ABSORPTION SPECTROSCOPY FOR THEand x-ray emission and absorption spectroscopy. The first

Jaklevic, J. M.

2011-01-01T23:59:59.000Z

390

Ultrafast X-ray Phase-Enhanced Microimaging for Visualizing Fuel...  

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

Ultrafast X-ray Phase-Enhanced Microimaging for Visualizing Fuel Injection Process and Diesel Sprays Ultrafast X-ray Phase-Enhanced Microimaging for Visualizing Fuel Injection...

391

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

NLE Websites -- All DOE Office Websites (Extended Search)

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

392

Synchrotron X-ray Studies of Super-critical Carbon Dioxide /...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Synchrotron X-ray Studies of Super-critical Carbon Dioxide Reservoir Rock Interfaces Synchrotron X-ray Studies of Super-critical Carbon Dioxide Reservoir Rock Interfaces...

393

Using Light to Control How X Rays Interact with Matter  

NLE Websites -- All DOE Office Websites (Extended Search)

Using Light to Control How X Using Light to Control How X Rays Interact with Matter Using Light to Control How X Rays Interact with Matter Print Wednesday, 27 January 2010 00:00 Schemes that use one light pulse to manipulate interactions of another with matter are well developed in the visible-light regime where an optical control pulse influences how an optical probe pulse interacts with a medium. This approach has opened new research directions in fields like quantum computing and nonlinear optics, while also spawning entirely new research areas, such as electromagnetically induced transparency and slow light. However, it has been unclear whether similar optical control schemes could be used to modify how x rays interact with matter. In a dramatic breakthrough demonstration at the ALS, a Berkeley Lab-Argonne National Laboratory group has now used powerful visible-light lasers to render a nominally opaque material transparent to x rays. While x-ray transparency will have immediate applications at x-ray light sources, the important result is that the findings lay a foundation for a broader spectrum of applications.

394

Using Light to Control How X Rays Interact with Matter  

NLE Websites -- All DOE Office Websites (Extended Search)

Using Light to Control How X Rays Interact with Matter Print 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 visible-light regime where an optical control pulse influences how an optical probe pulse interacts with a medium. This approach has opened new research directions in fields like quantum computing and nonlinear optics, while also spawning entirely new research areas, such as electromagnetically induced transparency and slow light. However, it has been unclear whether similar optical control schemes could be used to modify how x rays interact with matter. In a dramatic breakthrough demonstration at the ALS, a Berkeley Lab-Argonne National Laboratory group has now used powerful visible-light lasers to render a nominally opaque material transparent to x rays. While x-ray transparency will have immediate applications at x-ray light sources, the important result is that the findings lay a foundation for a broader spectrum of applications.

395

Using Light to Control How X Rays Interact with Matter  

NLE Websites -- All DOE Office Websites (Extended Search)

Using Light to Control How X Rays Interact with Matter Print 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 visible-light regime where an optical control pulse influences how an optical probe pulse interacts with a medium. This approach has opened new research directions in fields like quantum computing and nonlinear optics, while also spawning entirely new research areas, such as electromagnetically induced transparency and slow light. However, it has been unclear whether similar optical control schemes could be used to modify how x rays interact with matter. In a dramatic breakthrough demonstration at the ALS, a Berkeley Lab-Argonne National Laboratory group has now used powerful visible-light lasers to render a nominally opaque material transparent to x rays. While x-ray transparency will have immediate applications at x-ray light sources, the important result is that the findings lay a foundation for a broader spectrum of applications.

396

Dilation x-ray imager a new/faster gated x-ray imager for the NIF  

SciTech Connect

As the yield on implosion shots increases it is expected that the peak x-ray emission reduces to a duration with a FWHM as short as 20 ps for {approx}7 Multiplication-Sign 10{sup 18} neutron yield. However, the temporal resolution of currently used gated x-ray imagers on the NIF is 40-100 ps. We discuss the benefits of the higher temporal resolution for the NIF and present performance measurements for dilation x-ray imager, which utilizes pulse-dilation technology [T. J. Hilsabeck et al., Rev. Sci. Instrum. 81, 10E317 (2010)] to achieve x-ray imaging with temporal gate times below 10 ps. The measurements were conducted using the COMET laser, which is part of the Jupiter Laser Facility at the Lawrence Livermore National Laboratory.

Nagel, S. R.; Bell, P. M.; Bradley, D. K.; Ayers, M. J.; Barrios, M. A.; Felker, B.; Smith, R. F.; Collins, G. W.; Jones, O. S.; Piston, K.; Raman, K. S. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Hilsabeck, T. J.; Kilkenny, J. D.; Chung, T.; Sammuli, B. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Hares, J. D.; Dymoke-Bradshaw, A. K. L. [Kentech Instruments Ltd., Wallingford, Oxfordshire OX10 (United Kingdom)

2012-10-15T23:59:59.000Z

397

Modeling the high resolution X-ray spectra from the relativistic jets of the X-ray binary SS 433  

E-Print Network (OSTI)

We test the physical model of the relativistic jets in the galactic X-ray binary SS 433 that was proposed by Marshall et al. 2002 (Paper I) using additional observations from the Chandra High Energy Transmission Grating ...

Lopez, Laura Ann, 1982-

2004-01-01T23:59:59.000Z

398

Gain dynamics in a soft X-ray laser ampli er perturbed by a strong injected X-ray eld  

SciTech Connect

Seeding soft X-ray plasma ampli ers with high harmonics has been demonstrated to generate high-brightness soft X-ray laser pulses with full spatial and temporal coherence. The interaction between the injected coherent eld and the swept-gain medium has been modelled. However, no exper- iment has been conducted to probe the gain dynamics when perturbed by a strong external seed eld. Here, we report the rst X-ray pump X-ray probe measurement of the nonlinear response of a plasma ampli er perturbed by a strong soft X-ray ultra-short pulse. We injected a sequence of two time-delayed high-harmonic pulses (l518.9 nm) into a collisionally excited nickel-like molybdenum plasma to measure with femto-second resolution the gain depletion induced by the saturated ampli cation of the high-harmonic pump and its subsequent recovery. The measured fast gain recovery in 1.5 1.75 ps con rms the possibility to generate ultra-intense, fully phase-coherent soft X-ray lasers by chirped pulse ampli cation in plasma ampli ers.

Wang, Yong [Colorado State University, Fort Collins] [Colorado State University, Fort Collins; Wang, Shoujun [Colorado State University, Fort Collins] [Colorado State University, Fort Collins; Oliva, E [Laboratoire de Physique des Gaz et des Gaz et des Plasmas] [Laboratoire de Physique des Gaz et des Gaz et des Plasmas; Lu, L [Laboratoire de Physique des Gaz et des Gaz et des Plasmas] [Laboratoire de Physique des Gaz et des Gaz et des Plasmas; Berrill, Mark A [ORNL] [ORNL; Yin, Liang [Colorado State University, Fort Collins] [Colorado State University, Fort Collins; Nejdl, J [Colorado State University, Fort Collins] [Colorado State University, Fort Collins; Luther, Brad [Colorado State University, Fort Collins] [Colorado State University, Fort Collins; Proux, C [Laboratoire d’Optique Applique´e, ENSTA, CNRS, Ecole Polytechnique] [Laboratoire d’Optique Applique´e, ENSTA, CNRS, Ecole Polytechnique; Le, T. T. [Laboratoire de Physique des Gaz et des Gaz et des Plasmas] [Laboratoire de Physique des Gaz et des Gaz et des Plasmas; Dunn, James [Lawrence Livermore National Laboratory (LLNL)] [Lawrence Livermore National Laboratory (LLNL); Ros, D [Laboratoire de Physique des Gaz et des Gaz et des Plasmas] [Laboratoire de Physique des Gaz et des Gaz et des Plasmas; Zeitoun, Philippe [École Polytechnique] [École Polytechnique; Rocca, Jorge [Colorado State University, Fort Collins] [Colorado State University, Fort Collins

2014-01-01T23:59:59.000Z

399

Diffracted X-ray tracking for monitoring intramolecular motion in individual protein molecules using broad band X-ray  

SciTech Connect

Diffracted X-ray tracking (DXT) enables the tilting and twisting motions of single protein molecules to be monitored with micro- to milliradian resolution using a highly brilliant X-ray source with a wide energy bandwidth. We have developed a technique to monitor single molecules using gold nanocrystals attached to individual protein molecules using the BL28B2 beamline at SPring-8. In this paper we present the installation of a single toroidal X-ray mirror at BL28B2 to focus X-rays in an energy range of 10–20 keV (?E/E = 82% for an X-ray with a wide energy bandwidth). With this beamline we tracked diffraction spots from gold nanocrystals over a wide angle range than that using quasi-monochromatic X-rays. Application of the wide angle DXT technique to biological systems enabled us to observe the on-site motions of single protein molecules that have been functionalized in vivo. We further extend the capability of DXT by observing the fractional tilting and twisting motions of inner proteins under various conditions. As a proof of this methodology and to determine instrumental performance the intramolecular motions of a human serum albumin complex with 2-anthracenecarboxylic acid was investigated using the BL28B2 beamline. The random tilting and twisting intramolecular motions are shown to be directly linked to the movement of individual protein molecules in the buffer solution.

Ichiyanagi, Kouhei; Sasaki, Yuji C. [Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 609 Kiban Building 5-1-5 Kashiwanoha, Kahiwashi, Chiba 277-8561 (Japan) [Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 609 Kiban Building 5-1-5 Kashiwanoha, Kahiwashi, Chiba 277-8561 (Japan); Japan Science and Technology Agency, CREST, CREST, Sasaki-Team, 609 Kiban Building, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan); Sekiguchi, Hiroshi; Hoshino, Masato; Kajiwara, Kentaro; Senba, Yasunori; Ohashi, Haruhiko; Ohta, Noboru [Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)] [Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Hoshisashi, Kentaro; Jae-won, Chang; Tokue, Maki; Matsushita, Yufuku [Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 609 Kiban Building 5-1-5 Kashiwanoha, Kahiwashi, Chiba 277-8561 (Japan)] [Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 609 Kiban Building 5-1-5 Kashiwanoha, Kahiwashi, Chiba 277-8561 (Japan); Nishijima, Masaki; Inoue, Yoshihisa [Department of Applied Chemistry and Office for University-Industry Collaboration, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)] [Department of Applied Chemistry and Office for University-Industry Collaboration, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Yagi, Naoto [Japan Science and Technology Agency, CREST, CREST, Sasaki-Team, 609 Kiban Building, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan) [Japan Science and Technology Agency, CREST, CREST, Sasaki-Team, 609 Kiban Building, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan); Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)

2013-10-15T23:59:59.000Z

400

Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism  

NLE Websites -- All DOE Office Websites (Extended Search)

Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism Print Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism Print 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 linear dichroism (XMLD) are not only determined by the relative orientation of magnetic moments and x-ray polarization, but their orientation relative to the crystallographic axes must be taken into account for accurate interpretation of XMLD data. Magnetism and X Rays The ancient Greeks and also the Chinese knew about strange and rare stones with the power to attract iron. Moreover, when freely suspended these objects pointed north-south. Throughout the past, we have used this phenomenon-magnetism-for navigation and more recently for power production and digital information storage, all while trying to explore and understand its origins. In 1986 researchers at a facility similar to the ALS observed for the first time that the absorption of x rays depends not only on the composition of a material-that is, if it contains iron, nickel, or other elements-but also on its magnetism. The effect is unique in that it allows us to distinguish which atomic species magnetism originates from and provides information about their local atomic environment-for example, whether a magnetic species is surrounded by 4 or 6 oxygen atoms. A research team at the ALS has now shown that the relationship between magnetic order and absorption of x rays is even more complex and exciting than has been assumed for the past 20 years, leading to a reassessment of previous results.

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism  

NLE Websites -- All DOE Office Websites (Extended Search)

Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism Print Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism Print 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 linear dichroism (XMLD) are not only determined by the relative orientation of magnetic moments and x-ray polarization, but their orientation relative to the crystallographic axes must be taken into account for accurate interpretation of XMLD data. Magnetism and X Rays The ancient Greeks and also the Chinese knew about strange and rare stones with the power to attract iron. Moreover, when freely suspended these objects pointed north-south. Throughout the past, we have used this phenomenon-magnetism-for navigation and more recently for power production and digital information storage, all while trying to explore and understand its origins. In 1986 researchers at a facility similar to the ALS observed for the first time that the absorption of x rays depends not only on the composition of a material-that is, if it contains iron, nickel, or other elements-but also on its magnetism. The effect is unique in that it allows us to distinguish which atomic species magnetism originates from and provides information about their local atomic environment-for example, whether a magnetic species is surrounded by 4 or 6 oxygen atoms. A research team at the ALS has now shown that the relationship between magnetic order and absorption of x rays is even more complex and exciting than has been assumed for the past 20 years, leading to a reassessment of previous results.

402

Neutron and X-Ray Scattering - Argonne National Laboratories, Materials  

NLE Websites -- All DOE Office Websites (Extended Search)

Home Home Neutron and X-Ray Scattering Neutron and X-ray Scattering Science Recent advances in neutron and x-ray scattering instrumentation at major DOE facilities such as the Spallation Neutron Source and Advanced Photon Source provide unprecedented insights into complex phenomena in bulk and interfacial materials. The vision of our group is to harness the complementarity of neutrons and x-rays to study how materials respond on a range of length and time scales to phase competition, so that we can learn to control emergent behavior and generate functional properties in energy-related materials. We use neutrons and x-rays to investigate the structure and dynamics of bulk and interfacial materials with properties that are useful for energy applications, such as superconductivity, magnetism and thermoelectricity. Phase competition can generate or enhance such properties, but it is extremely challenging to characterize fluctuations in the competing order, whether in bulk disordered materials, or artificial heterostructures. Our goal is to utilize efficient techniques that we have been developing for measuring nanoscale phase fluctuations, both static and dynamic, to enable the rational design of new materials for energy within MSD.

403

Optics-free x-ray FEL oscillator  

SciTech Connect

There is a need for an Optics-Free FEL Oscillators (OFFELO) to further the advantages of free-electron lasers and turning them in fully coherent light sources. While SASE (Self-Amplified Spontaneous Emission) FELs demonstrated the capability of providing very high gain and short pulses of radiation and scalability to the X-ray range, the spectra of SASE FELs remains rather wide ({approx}0.5%-1%) compared with typical short wavelengths FEL-oscillators (0.01%-0.0003% in OK-4 FEL). Absence of good optics in VUV and X-ray ranges makes traditional oscillator schemes with very high average and peak spectral brightness either very complex or, strictly speaking, impossible. In this paper, we discuss lattice of the X-ray optics-free FEL oscillator and present results of initial computer simulations of the feedback process and the evolution of FEL spectrum in X-ray OFFELO. We also discuss main limiting factors and feasibility of X-ray OFFELO.

Litvinenko, V.N.; Hao, Y.; Kayran, D.; Trbojevic, D.

2011-03-28T23:59:59.000Z

404

NuSTAR Observations of X-Ray Binaries  

E-Print Network (OSTI)

As of 2014 August, the Nuclear Spectroscopic Telescope Array (NuSTAR) had observed ~30 X-ray binaries either as part of the planned program, as targets of opportunity, or for instrument calibration. The main science goals for the observations include probing the inner part of the accretion disk and constraining black hole spins via reflection components, providing the first observations of hard X-ray emission from quiescent Low Mass X-ray Binaries (LMXBs), measuring cyclotron lines from accreting pulsars, and studying type I X-ray bursts from neutron stars. Here, we describe the science objectives in more depth and give an overview of the NuSTAR observations that have been carried out to achieve the objectives. These include observation of four "IGR" High Mass X-ray Binaries (HMXBs) discovered by INTEGRAL. We also summarize the results that have been obtained and their implications. Among the IGR HMXBs, we focus on the discovery of a cyclotron line in the spectrum of IGR J17544-2619.

Tomsick, John A; Fuerst, Felix; Harrison, Fiona; Miyasaka, Hiromasa; Tendulkar, Shriharsh; Bhalerao, Varun; Chakrabarty, Deepto; King, Ashley; Miller, Jon M; Natalucci, Lorenzo; Stern, Daniel

2015-01-01T23:59:59.000Z

405

Method and apparatus for micromachining using hard X-rays  

DOE Patents (OSTI)

An X-ray source such as a synchrotron which provides a significant spectral content of hard X-rays is used to expose relatively thick photoresist such that the portions of the photoresist at an exit surface receive at least a threshold dose sufficient to render the photoresist susceptible to a developer, while the entrance surface of the photoresist receives an exposure which does not exceed a power limit at which destructive disruption of the photoresist would occur. The X-ray beam is spectrally shaped to substantially eliminate lower energy photons while allowing a substantial flux of higher energy photons to pass through to the photoresist target. Filters and the substrate of the X-ray mask may be used to spectrally shape the X-ray beam. Machining of photoresists such as polymethylmethacrylate to micron tolerances may be obtained to depths of several centimeters, and multiple targets may be exposed simultaneously. The photoresist target may be rotated and/or translated in the beam to form solids of rotation and other complex three-dimensional structures. 21 figs.

Siddons, D.P.; Johnson, E.D.; Guckel, H.; Klein, J.L.

1997-10-21T23:59:59.000Z

406

Method and apparatus for micromachining using hard X-rays  

DOE Patents (OSTI)

An X-ray source such as a synchrotron which provides a significant spectral content of hard X-rays is used to expose relatively thick photoresist such that the portions of the photoresist at an exit surface receive at least a threshold dose sufficient to render the photoresist susceptible to a developer, while the entrance surface of the photoresist receives an exposure which does not exceed a power limit at which destructive disruption of the photoresist would occur. The X-ray beam is spectrally shaped to substantially eliminate lower energy photons while allowing a substantial flux of higher energy photons to pass through to the photoresist target. Filters and the substrate of the X-ray mask may be used to spectrally shape the X-ray beam. Machining of photoresists such as polymethylmethacrylate to micron tolerances may be obtained to depths of several centimeters, and multiple targets may be exposed simultaneously. The photoresist target may be rotated and/or translated in the beam to form solids of rotation and other complex three-dimensional structures.

Siddons, David Peter (Shoreham, NY); Johnson, Erik D. (Ridge, NY); Guckel, Henry (Madison, WI); Klein, Jonathan L. (Madison, WI)

1997-10-21T23:59:59.000Z

407

The History of X-ray Free-Electron Lasers  

SciTech Connect

The successful lasing at the SLAC National Accelerator Laboratory of the Linear Coherent Light Source (LCLS), the first X-ray free-electron laser (X-ray FEL), in the wavelength range 1.5 to 15 {angstrom}, pulse duration of 60 to few femtoseconds, number of coherent photons per pulse from 10{sup 13} to 10{sup 11}, is a landmark event in the development of coherent electromagnetic radiation sources. Until now electrons traversing an undulator magnet in a synchrotron radiation storage ring provided the best X-ray sources. The LCLS has set a new standard, with a peak X-ray brightness higher by ten orders of magnitudes and pulse duration shorter by three orders of magnitudes. LCLS opens a new window in the exploration of matter at the atomic and molecular scales of length and time. Taking a motion picture of chemical processes in a few femtoseconds or less, unraveling the structure and dynamics of complex molecular systems, like proteins, are some of the exciting experiments made possible by LCLS and the other X-ray FELs now being built in Europe and Asia. In this paper, we describe the history of the many theoretical, experimental and technological discoveries and innovations, starting from the 1960s and 1970s, leading to the development of LCLS.

Pellegrini, C.; /UCLA /SLAC; ,

2012-06-28T23:59:59.000Z

408

Ultrafast x-ray diffraction of laser-irradiated crystals  

SciTech Connect

An apparatus has been developed for measuring time-dependent x-ray diffraction. X-ray pulses from an Advanced Light Source bend magnet are diffracted by a sagittally-focusing Si(111) crystal and then by a sample crystal, presently InSb(111). Laser pulses with 100 fs duration and a repetition rate of 1 KHz irradiate the sample inducing a phase transition. Two types of detectors are being employed: an x-ray streak camera and an avalanche photodiode. The streak camera is driven by a photoconductive switch and has a 2 ps temporal resolution determined by trigger jitter. The avalanche photodiode has high quantum efficiency and sufficient time resolution to detect single x-ray pulses in ALS two bunch or camshaft operation. A beamline is under construction dedicated for time resolved and micro-diffraction experiments. In the new beamline a toroidal mirror collects 3 mrad horizontally and makes a 1:1 image of the bend magnet source in the x-ray hutch. A laser induced phase transition has been observed in InSb occurring within 70 ps.

Heimann, P.A. [Lawrence Berkeley National Lab., CA (US). Advanced Light Source; Larsson, J. [Univ. of California, Berkeley, CA (US). Physics Dept.; Chang, Z. [Univ. of Michigan, Ann Arbor, MI (US). Center for Ultrafast Optical Science

1997-09-01T23:59:59.000Z

409

Implications of the X-Ray Properties of Pulsar Nebulae  

E-Print Network (OSTI)

A plausible model for the Crab Nebula is one in which a particle dominated, highly relativistic wind from the pulsar passes through a shock front in which the particles attain a power law energy distribution. The electrons and positrons lose energy radiating synchrotron emission. Here, a one zone version of the model is developed and applied to observations of X-ray pulsar nebulae. Efficient conversion of pulsar spin-down power to X-ray luminosity is expected if the observed electrons are in the synchrotron cooling regime and their energy spectrum is similar to that in the Crab Nebula. In this case, the relation between X-ray luminosity and pulsar spin-down power depends only weakly on the model parameters. The dependence is stronger for a steeper particle spectrum, as appears to be present in N157B, and the efficiency of X-ray production can be lower. If the electrons are not in the cooling regime, the X-ray luminosity can be low, as appears to be the case for the compact nebula around the Vela pulsar. Slow cooling is likely to be caused by a sub-equipartition magnetic field in the radiating region. Observations can place constraints on the uncertain physics of relativistic MHD shocks. The model is related to those developed for gamma-ray burst afterglows.

Roger A. Chevalier

2000-06-01T23:59:59.000Z

410

ON THE X-RAY OUTBURSTS OF TRANSIENT ANOMALOUS X-RAY PULSARS AND SOFT GAMMA-RAY REPEATERS  

SciTech Connect

We show that the X-ray outburst light curves of four transient anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs), namely, XTE J1810-197, SGR 0501+4516, SGR 1627-41, and CXOU J164710.2-455216, can be produced by the fallback disk model that was also applied to the outburst light curves of persistent AXPs and SGRs in our earlier work. The model solves the diffusion equation for the relaxation of a disk that has been pushed back by a soft gamma-ray burst. The sets of main disk parameters used for these transient sources are very similar to each other and to those employed in our earlier models of persistent AXPs and SGRs. There is a characteristic difference between the X-ray outburst light curves of transient and persistent sources. This can be explained by the differences in the disk surface density profiles of the transient and persistent sources in quiescence indicated by their quiescent X-ray luminosities. Our results imply that a viscous disk instability operating at a critical temperature in the range of {approx}1300-2800 K is a common property of all fallback disks around AXPs and SGRs. The effect of the instability is more pronounced and starts earlier for the sources with lower quiescent luminosities, which leads to the observable differences in the X-ray enhancement light curves of transient and persistent sources. A single active disk model with the same basic disk parameters can account for the enhancement phases of both transient and persistent AXPs and SGRs. We also present a detailed parameter study to show the effects of disk parameters on the evolution of the X-ray luminosity of AXPs and SGRs in the X-ray enhancement phases.

Cal Latin-Small-Letter-Dotless-I skan, Sirin; Ertan, Uenal [Sabanc Latin-Small-Letter-Dotless-I University, Orhanl Latin-Small-Letter-Dotless-I -Tuzla, Istanbul, 34956 (Turkey)

2012-10-20T23:59:59.000Z

411

X-ray magnetic circular dichroism in (Ge,Mn) compounds: experiments and modeling Samuel Tardif,1, 2,  

E-Print Network (OSTI)

X-ray magnetic circular dichroism in (Ge,Mn) compounds: experiments and modeling Samuel Tardif,1, 2: July 29, 2013) X-ray absorption (XAS) and x-ray magnetic circular dichroism (XMCD) spectra at the L2),6 and x-ray spectroscopy (x-ray absorption spec- troscopy, XAS, and x-ray magnetic circular

412

Crystallization and preliminary X-ray crystallographic study of disproportionating enzyme from potato  

Science Journals Connector (OSTI)

Disproportionating enzyme from potato was crystallized and preliminarily analyzed using X-ray diffraction.

Imamura, K.

2004-12-24T23:59:59.000Z

413

Evolution of Cygnus X-3 through its Radio and X-ray States  

SciTech Connect

Based on X-ray spectra and studies of the long-term correlated behavior between radio and soft X-ray, we present a detailed evolution of Cyg X-3 through its radio and X-ray states. We comment on the nature of the hard X-ray tail and possible Simbol X contribution in constraining the models.

Szostek, A. [Laboratoire d'Astrophysique de Grenoble, CNRS, Universite Joseph Fourier, Grenoble (France); Astronomical Observatory, Jagiellonian University, Krakow (Poland); Zdziarski, A. A. [Centrum Astronomiczne im. M. Kopernika, Warszawa (Poland); McCollough, M. L. [Smithsonian Astrophysical Observatory, Cambridge (United States)

2009-05-11T23:59:59.000Z

414

Determination of the iron-sulfur distances in rubredoxin by x-ray absorption spectroscopy  

Science Journals Connector (OSTI)

...x-ray flux from the synchrotron radiation at the Stanford Synchroton Radiation Project has been used to study the extended x-ray...x-ray flux from the synchrotron radiation at the Stanford Synchroton Radiation Project has been used to study the extended x-ray...

R G Shulman; P Eisenberger; W E Blumberg; N A Stombaugh

1975-01-01T23:59:59.000Z

415

X-ray Diffraction / MSE 603 Spring 2002 Qun Shen / CHESS qs11@cornell.edu  

E-Print Network (OSTI)

X-ray Diffraction / MSE 603 Spring 2002 Qun Shen / CHESS qs11@cornell.edu 1. X-ray production & basic properties ­ common sources for diffraction experiments ­ synchrotron radiation ­ response to x-rays by an electron ­ refraction index ­ total external reflection & evanescent wave, TXRF 2. X-ray scattering basics

Shen, Qun

416

Soft X-Ray Diffraction Microscopy of a Frozen Hydrated Yeast Cell Xiaojing Huang,1  

E-Print Network (OSTI)

Soft X-Ray Diffraction Microscopy of a Frozen Hydrated Yeast Cell Xiaojing Huang,1 Johanna Nelson,1 eukaryotic cell using x-ray diffraction microscopy, or coherent x-ray diffraction imaging. By plunge freezingV x rays were recorded and reconstructed to reveal a budding yeast cell at a resolution better than 25

Mohseni, Hooman

417

X-ray Spectroscopy of O Supergiant Winds: Shock Physics, Clumping, and Mass-Loss Rates  

E-Print Network (OSTI)

X-ray Spectroscopy of O Supergiant Winds: Shock Physics, Clumping, and Mass-Loss Rates David Cohen Li (Swarthmore '16), Kelley Langhans (Swarthmore '16) #12;Talk Outline Context of O star X-ray emission: wind shocks 1. X-ray constraints on the shocked wind plasma 2. X-ray absorption as a mass

Cohen, David

418

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

E-Print Network (OSTI)

X-ray spectral diagnostics of neon photoionization experiments on the Z-machine David H. Cohen on an initial spectroscopic study of low-density, x-ray photoionized neon with x-ray spectroscopy plasma, and to explore issues related to the rapid x-ray photoionization of relatively cold, low

Cohen, David

419

X-ray absorption anisotropy for polychromatic illumination--Crystal views from inside  

E-Print Network (OSTI)

X-ray absorption anisotropy for polychromatic illumination--Crystal views from inside P. Korecki a Keywords: X-ray absorption Real-space imaging X-ray holography Electron channeling Electron backscatter of the fine structure in X-ray absorption anisotropy, which results from incident beam diffraction

Korecki, Pawe³

420

X-ray emission from clusters of galaxies Craig L. Sarazin  

E-Print Network (OSTI)

X-ray emission from clusters of galaxies Craig L. Sarazin Department of Astronomy, University show that they are bright x-ray sources, with luminosities of 1043 45 ergs/sec. It is now established the stars in all the galaxies in the cluster. The x-ray spectra of clusters show strong x-ray line emission

Sarazin, Craig

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University  

E-Print Network (OSTI)

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University Doc. No: SOPUSERFD form that can be accessed by the X-ray diffraction webpage. RESPONSIBILITY: The X-ray Diffraction and suggestions in a timely manner. MATERIALS: · Computer Database · Web interface #12;X-ray Diffraction

Meagher, Mary

422

X-ray four-wave mixing in molecules Satoshi Tanaka  

E-Print Network (OSTI)

X-ray four-wave mixing in molecules Satoshi Tanaka Department of Chemistry, University of Rochester radiation intense light sources have opened up a new era in soft x-ray spectroscopy. The dramatic improvements of spectral resolution in x-ray absorption1,2 and x-ray photoemission spectra3 have revealed

Mukamel, Shaul

423

X-Ray: A Tool for Automatic Measurement of Hardware Parameters  

E-Print Network (OSTI)

X-Ray: A Tool for Automatic Measurement of Hardware Parameters Kamen Yotov, Keshav Pingali, Paul and register tiles. In this paper, we describe X-Ray1 , a system for im- plementing micro-benchmarks to measure. Experimen- tal evaluations of X-Ray on traditional workstations, servers and embedded systems show that X-Ray

Pingali, Keshav K.

424

A low-cost X-ray-transparent experimental cell for synchrotron-based X-ray microtomography studies under geological reservoir conditions  

Science Journals Connector (OSTI)

An X-ray-transparent experimental environment that allows time-resolved studies of porous rocks under geological reservoir conditions using high-energy synchrotron X-ray microtomography is presented.

Fusseis, F.

2013-12-05T23:59:59.000Z

425

Detection limits of high temperature superconducting materials on various substrates by energy dispersive X-ray fluorescence and proton induced X-ray emission methods  

Science Journals Connector (OSTI)

Application of energy dispersive X-ray fluorescence (EDXRF) and proton induced X-ray emission (PIXE) methods has been demonstrated for determining the elemental composition of thin film superconducting materia...

M Lal; H N Bajpai; D Joseph; R K Choudhury

1990-04-01T23:59:59.000Z

426

‘Taking X-ray phase contrast imaging into mainstream applications’ and its satellite workshop ‘Real and reciprocal space X-ray imaging’  

Science Journals Connector (OSTI)

...presented Femtosecond X-ray lasers for imaging atomic structure...which he described X-ray laser-induced electronic ordering...characterization of targets for laser fusion experiments. Krist. Tech...1205396109 ) 20 Talbot, HF . 1836 Facts relating to...

2014-01-01T23:59:59.000Z

427

X-ray movies reveal insect flight, muscle motion  

NLE Websites -- All DOE Office Websites (Extended Search)

BioCAT BioCAT X-ray movies reveal insect flight, muscle motion Photo credit: Michael Dickinson Watching flies fly may not seem like high-tech science, but for researchers using the Western Hemisphere's most brilliant X-rays, from the Advanced Photon Source located at the U.S. Department of Energy's Argonne National Laboratory, it not only helps explain how insects fly but also may someday aid in understanding human heart function. The researchers, from the Illinois Institute of Technology (IIT), Caltech and the University of Vermont, merged two distinct technologies, intense X-ray beams and electronic flight simulators, to study how insect muscles can generate such extraordinary levels of power. The results are published in the the January 20,. 2005, issue of the journal Nature.

428

X-ray Microscopy and Imaging (XSD-XMI)  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging (XMI) Imaging (XMI) About XMI Science and Research Beamlines Highlights Software and Tools Intranet Search APS... Argonne Home > Advanced Photon Source > Contacts FAQs Beamlines News Publications APS Email Portal APS Intranet APS Phonebook APS Quick Links for Users APS Safety and Training Welcome to the X-ray Microscopy and Imaging group (XMI)! X-ray Microscopy and Imaging is part of the X-ray Science Division at the Advanced Photon Source. We develop and support a diverse and multidisciplinary user research program at Sectors 2 and 32 of the APS, with the overall goal to image and study materials structures at spatial and temporal resolutions that are most scientifically relevant to the cutting-edge advances in materials, biological, environmental, and biomedical sciences. To achieve this goal, we actively engage in various research activities including

429

Photon Sciences | Beamlines | XPD: X-ray Powder Diffraction  

NLE Websites -- All DOE Office Websites (Extended Search)

XPD: X-ray Powder Diffraction XPD: X-ray Powder Diffraction Poster | Fact Sheet | Preliminary Design Report Scientific Scope XPD is a tunable facility with the ability to collect diffraction data at high x-ray energies (40keV-80keV), offering rapid acquisition (millisecond) and high angular resolution capabilities on the same instrument. XPD addresses future scientific challenges in, for example, hydrogen storage, CO2 sequestration, advanced structural ceramics, catalysis, and materials processing. Such materials of high technological value often are complex, nanostructured and heterogeneous. The scientific grand challenge is to obtain robust and quantitative (micro)structural information, not only in the ground state at ambient conditions, but also in situ or in operando with varying temperature, pressure, magnetic/electric/stress

430

Workshop on Time Domain Science Using X-ray Techniques  

NLE Websites -- All DOE Office Websites (Extended Search)

Time-Resolved Beamlines Time-Resolved Beamlines Advisory Committee Workshop Home Workshop Chairs: Lin Chen (Argonne National Laboratory) Steve Milton (Advanced Photon Source) David Reis (University of Michigan) Linda Young (Argonne National Laboratory) Workshop on Time Domain Science Using X-ray Techniques August 29 September 1, 2004, The Abbey, Fontana, Lake Geneva Area, Wisconsin A workshop on "Time Domain Science Using X-ray Techniques" was held from August 29 September 1, 2004 , welcoming both experts and beginners in the field. This is one of the concurrently held workshops in the series on "Future Scientific Directions for the Advanced Photon Source." The goal of the workshop was to identify future directions in scientific research using time resolved x-ray techniques and to address possiblities to produce ps

431

X-RAY FLUORESCENCE MICROPROBE (XFM) TECHNIQUES AND CAPABILITIES  

NLE Websites -- All DOE Office Websites (Extended Search)

RAY FLUORESCENCE MICROPROBE (XFM) RAY FLUORESCENCE MICROPROBE (XFM) TECHNIQUES AND CAPABILITIES APPLICATIONS WORLD-LEADING MICROFOCUSED EXAFS SPECTROSCOPY * XFM is an optimized three-pole wiggler beamline for the characterization of materials in an "as-is" state that are chemically heterogeneous at the micrometer scale via synchrotron induced X-ray fluorescence. * XFM includes instrumentation for microbeam X-ray fluorescence (µXRF), diffraction (µXRD) and fluorescence computed microtomography (FCMT) . However, it is optimized to provide users state-of-the-art microfocused Extended X-ray Absorption Fine Structure (µEXAFS) spectroscopy between 4 to 20 keV. * XFM will trade-off beam size and flux for sample configuration flexibility. This includes more readily achievable stability

432

Portable X-Ray, K-Edge Heavy Metal Detector  

SciTech Connect

The X-Ray, K-Edge Heavy Metal Detection System was designed and built by Ames Laboratory and the Center for Nondestructive Evaluation at Iowa State University. The system uses a C-frame inspection head with an X-ray tube mounted on one side of the frame and an imaging unit and a high purity germanium detector on the other side. the inspection head is portable and can be easily positioned around ventilation ducts and pipes up to 36 inches in diameter. Wide angle and narrow beam X-ray shots are used to identify the type of holdup material and the amount of the contaminant. Precise assay data can be obtained within minutes of the interrogation. A profile of the containerized holdup material and a permanent record of the measurement are immediately available.

Fricke, V.

1999-10-25T23:59:59.000Z

433

Fast microtomography using bright monochromatic x-rays  

SciTech Connect

A fast microtomography system for high-resolution high-speed imaging has been developed using bright monochromatic x-rays at the BL29XU beamline of SPring-8. The shortest scan time for microtomography we attained was 0.25 s in 1.25 {mu}m effective pixel size by combining the bright monochromatic x-rays, a fast rotating sample stage, and a high performance x-ray imaging detector. The feasibility of the tomography system was successfully demonstrated by visualization of rising bubbles in a viscous liquid, an interesting issue in multiphase flow physics. This system also provides a high spatial (a measurable feature size of 300 nm) or a very high temporal (9.8 {mu}s) resolution in radiographs.

Jung, J. W.; Lee, J. S.; Park, S. J.; Chang, S.; Pyo, J. [X-ray Imaging Center, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang 790-784 (Korea, Republic of); Department of Materials Science and Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang 790-784 (Korea, Republic of); Kwon, N.; Kim, J. [X-ray Imaging Center, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang 790-784 (Korea, Republic of); School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Kohmura, Y.; Nishino, Y.; Yamamoto, M.; Ishikawa, T. [RIKEN/SPring-8, 1-1-1 Kouto, Mikazuki-cho, Sayo-gun, Hyogo 679-5148 (Japan); Je, J. H. [X-ray Imaging Center, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang 790-784 (Korea, Republic of); Department of Materials Science and Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang 790-784 (Korea, Republic of); School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); RIKEN/SPring-8, 1-1-1 Kouto, Mikazuki-cho, Sayo-gun, Hyogo 679-5148 (Japan)

2012-09-15T23:59:59.000Z

434

Movable anode x-ray source with enhanced anode cooling  

DOE Patents (OSTI)

An x-ray source is disclosed having a cathode and a disc-shaped anode with a peripheral surface at constant radius from the anode axis opposed to the cathode. The anode has stub axle sections rotatably carried in heat conducting bearing plates which are mounted by thermoelectric coolers to bellows which normally bias the bearing plates to a retracted position spaced from opposing anode side faces. The bellows cooperate with the x-ray source mounting structure for forming closed passages for heat transport fluid. Flow of such fluid under pressure expands the bellows and brings the bearing plates into heat conducting contact with the anode side faces. A worm gear is mounted on a shaft and engages serrations in the anode periphery for rotating the anode when flow of coolant is terminated between x-ray emission events. 5 figs.

Bird, C.R.; Rockett, P.D.

1987-08-04T23:59:59.000Z

435

Physical origin of X-ray flares following GRBs  

E-Print Network (OSTI)

One of the major achievements of Swift is the discovery of the erratic X-ray flares harboring nearly half of gamma-ray bursts (GRBs), both for long-duration and short-duration categories, and both for traditional hard GRBs and soft X-ray flashes (XRFs). Here I review the arguments in support of the suggestion that they are powered by reactivation of the GRB central engine, and that the emission site is typically ``internal'', i.e. at a distance within the forward shock front. The curvature effect that characterizes the decaying lightcurve slope during the fading phase of the flares provides an important clue. I will then discuss several suggestions to re-start the GRB central engine and comment on how future observations may help to unveil the physical origin of X-ray flares.

Bing Zhang

2006-02-25T23:59:59.000Z

436

Theory of angular dispersive imaging hard x-ray spectrographs  

E-Print Network (OSTI)

A spectrograph is an optical instrument that disperses photons of different energies into distinct directions and space locations, and images photon spectra on a position-sensitive detector. Spectrographs consist of collimating, angular dispersive, and focusing optical elements. Bragg reflecting crystals arranged in an asymmetric scattering geometry are used as the dispersing elements. A ray-transfer matrix technique is applied to propagate x-rays through the optical elements. Several optical designs of hard x-ray spectrographs are proposed and their performance is analyzed. Spectrographs with an energy resolution of 0.1 meV and a spectral window of imaging up to a few tens of meVs are shown to be feasible for inelastic x-ray scattering (IXS) spectroscopy applications. In another example, a spectrograph with a 1-meV spectral resolution and 85-meV spectral window of imaging is considered for Cu K-edge resonant IXS (RIXS).

Shvyd'ko, Yuri

2015-01-01T23:59:59.000Z

437

The Large Observatory For X-ray Timing: LOFT  

E-Print Network (OSTI)

LOFT, the Large Observatory for X-ray Timing, is a new space mission concept devoted to observations of Galactic and extra-Galactic sources in the X-ray domain with the main goals of probing gravity theory in the very strong field environment of black holes and other compact objects, and investigating the state of matter at supra-nuclear densities in neutron stars. The instruments on-board LOFT, the Large area detector and the Wide Field Monitor combine for the first time an unprecedented large effective area (~10 m2 at 8 keV) sensitive to X-ray photons mainly in the 2-30 keV energy range and a spectral resolution approaching that of CCD-based telescopes (down to 200 eV at 6 keV). LOFT is currently competing for a launch of opportunity in 2022 together with the other M3 mission candidates of the ESA Cosmic Vision Program.

Bozzo, E

2013-01-01T23:59:59.000Z

438

Multiple X-ray reflection from ionized slabs  

E-Print Network (OSTI)

Multiple reflection of X-rays may be important when an accretion disc and its hot corona have a complicated geometry, or if returning radiation due to gravitational light bending is important, or in emission from a funnel such as proposed in some gamma-ray burst models. We simulate the effects of multiple reflection by modifying the boundary condition for an X-ray illuminated slab. Multiple reflection makes the soft X-ray spectrum steeper (softer) and strengthens broad emission and absorption features, especially the K-shell features of iron. This may be important in explaining the spectra of sources such as the Narrow-Line Seyfert 1 galaxy 1H0707-495.

R. R. Ross; A. C. Fabian; D. R. Ballantyne

2002-06-11T23:59:59.000Z

439

Explosive hydrogen burning during type I X-ray bursts  

SciTech Connect

Explosive hydrogen burning in type I X-ray bursts (XRBs) is driven by charged particle reactions creating isotopes with masses up to A {approx} 100. Since charged particle reactions in a stellar environment are very temperature sensitive, we use a realistic time-dependent general relativistic and self-consistent model of type I X-ray bursts to provide accurate values of the burst temperatures and densities. This allows a detailed and accurate time-dependent identification of the reaction flow from the surface layers through the convective region and the ignition region to the neutron star ocean. Using this, we determine the relative importance of specific nuclear reactions in the X-ray burst.

Fisker, J L; Schatz, H; Thielemann, F

2007-06-11T23:59:59.000Z

440

High-Energy Diffraction-Enhanced X-ray Imaging  

SciTech Connect

In order to apply the diffraction-enhanced X-ray imaging (DEI) method for much wider variety of samples, we have developed the high-energy DEI system. The energy of X-ray was increased up to 70 keV to achieve high permeability for heavy elements. The diffraction of Si(440) was used to keep large field of view. Demonstrative observation of an electrical cable was performed using the X-ray emitted from the vertical wiggler. The obtained images visualized not only the core and ground wire made of copper but also the isolator and outer jacket made of polymer clearly. The comparison of images obtained by the DEI and the absorption-contrast imaging showed that the sensitivity of DEI is about 10 times higher than that of the absorption method for light elements, and 3 times for heavy elements.

Yoneyama, Akio; Ueda, Kazuhiro [Advanced Research Laboratory, Hitachi Ltd., 2520, Akanuma, Hatoyama, Saitama, 350-0395 (Japan); Takeda, Tohoru [Allied Health Sciences, Kitasato University, Sagamihara, Kanagawa 228-8555 (Japan); Yamazaki, Takanori [Research and Development Laboratory, Hitachi Cable, Ltd., 5-1-1, Hidakacho, Hitachi, Ibaraki, 319-1414 (Japan); Hyodo, Kazuyuki [Institute of Materials Science, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki, 305-0801 (Japan)

2010-06-23T23:59:59.000Z

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

X-ray Phase Contrast analysis - Digital wavefront development  

SciTech Connect

Optical schemes that enable imaging of the phase shift produced by an object have become popular in the x-ray region, where phase can be the dominant contrast mechanism. The propagation-based technique consists of recording the interference pattern produced by choosing one or several sample-to-detector distances. Pioneering studies, carried out making use of synchrotron radiation, demonstrated that this technique results in a dramatic increase of image contrast and detail visibility, allowing the detection of structures invisible with conventional techniques. An experimental and theoretical study of in-line hard x-ray phase-contrast imaging had been performed. The theoretical description of the technique is based on Fresnel diffraction. As an illustration of the potential of this quantitative imaging technique, high-resolution x-ray phase contrast images of simple objects will be presented.

Idir, Mourad [Metrology Beamline, Synchrotron SOLEIL, Gif-sur-Yvette (France); Potier, Jonathan [Phaseview, Palaiseau (France); Universite Paul Sabatier-Toulouse III, Metrology Beamline, Synchrotron SOLEIL, Gif-sur-Yvette (France); Fricker, Sebastien [Phaseview, Palaiseau (France); Snigirev, Anatoly; Snigireva, Irina [ESRF, Grenoble (France); Modi, M. H. [X-ray Optics Section, Raja Ramanna Centre for Advanced Technology, Indore (India)

2010-06-23T23:59:59.000Z

442

Nondispersive x-ray diagnostics of short lived plasmas  

SciTech Connect

In this NATO Advanced Study Institute, we have discussed in detail the diagnosis of many pulse power machine properties, including their electrical behavior, grounding and shielding, and related data acquisition techniques. The purpose for many of these machines is to create high temperature/high density plasmas and, therefore, the subsequent behavior of these plasmas is of critical concern. The energy density of these plasmas is such that they will naturally radiate in the x-ray regime and thus the diagnosis of their x-ray emission is a crucial measurement of the entire system performance. In this lecture, I describe the general techniques used to perform nondispersive x-ray diagnostics of these short lived plasmas.

Day, R.H.

1983-01-01T23:59:59.000Z

443

Fundamental physics at an X-ray free electron laser  

E-Print Network (OSTI)

X-ray free electron lasers (FELs) have been proposed to be constructed both at SLAC in the form of the so-called Linac Coherent Light Source as well as at DESY, where the so-called XFEL laboratory is part of the design of the electron-positron linear collider TESLA. In addition to the immediate applications in condensed matter physics, chemistry, material science, and structural biology, X-ray FELs may be employed also to study some physics issues of fundamental nature. In this context, one may mention the boiling of the vacuum (Schwinger pair creation in an external field), horizon physics (Unruh effect), and axion production. We review these X-ray FEL opportunities of fundamental physics and discuss the necessary technological improvements in order to achieve these goals.

A. Ringwald

2001-12-19T23:59:59.000Z

444

Experiment Hazard Class 8.3 - X-Ray Generators  

NLE Websites -- All DOE Office Websites (Extended Search)

3 - X-Ray Generators 3 - X-Ray Generators Applicability This hazard classification applies to all experiments involving the use of X-Ray Generators (other than the APS storage ring). As specified in LMS-PROC-109 a Radiation Generating Device (RGD) must be registered with the Argonne RGD Safety Officer using the ANL-847 form. The RGD will be assigned an inventory number, hazard class, RWP requirement, and inspection and survey frequencies. Experiment Category Experiments the Experiment Hazard Class are always categorized as High Risk. Experiment Hazard Control Verification Statements Engineered Controls - As determined in LMS-PROC-109. Samples chambers and all beam paths are fully enclosed by barriers. Class 2 and higher RGDs require an interlock to fail-safe beam shutter/beam stop or radiation

445

Plasma focus x?ray source for lithography  

Science Journals Connector (OSTI)

A bright and reliable x?ray source for lithography has been developed using plasma focus.Discharge with constant pressure gas one of the features of plasma focus makes the x?ray source system simple and lengthens lifetime. A fine ceramicinsulator made of alumina in place of a conventional Pyrex glass insulator improves system reliability. The system operates for more than 105discharges without maintenance. The lifetime of the system is ten times longer than that of a conventional plasma focusdevice. The resolution of a pattern printed by multishot exposure depends not only on the diameter of pinched plasma but also on the variation of source position. A new spherical electrode surrounding the plasma?focusing space is added to stabilize the location of the spot on the axis by eddy currents which exert the Lorentz force on the plasma. The spot position deviation has become negligibly small as compared with the pinched plasma diameter. The x?ray source size for neon is 1 mm in diameter and 10 mm in length. Consequently 0.4??m fine pattern has been printed with this source. Neon radiates intense x rays in opposite voltage polarity to that of a conventional plasma focus. Polarity inversion enables a very thin beryllium window to be located on the axis with the assistance of magnetic deflector and plasma stop. An x?ray intensity of 5 mJ/cm2/shot 25 cm from the source with an irradiance of 10 mW/cm2 at the 2?Hz repetition rate has been obtained. The plasma focus is a promising x?ray source for lithography from the viewpoint of intensity resolution and lifetime.

Yasuo Kato; Isao Ochiai; Yoshio Watanabe; Seiichi Murayama

1988-01-01T23:59:59.000Z

446

Measurements of the hard-x-ray reflectivity of iridium  

SciTech Connect

In connection with the design of a hard-x-ray telescope for the Constellation X-Ray Observatory we measured the reflectivity of an iridium-coated zerodur substrate as a function of angle at 55, 60, 70, and 80 keV at the National Synchrotron Light Source of Brookhaven National Laboratory. The optical constants were derived from the reflectivity data. The real component of the index of refraction is in excellent agreement with theoretical values at all four energies. However, the imaginary component, which is related to the mass attenuation coefficient, is 50% to 70% larger at 55, 60, and 70 keV than theoretical values.

Romaine, S.; Bruni, R.; Gorenstein, P.; Zhong, Z

2007-01-10T23:59:59.000Z

447

A New Measurement of the Cosmic X-ray Background  

SciTech Connect

I present a new analytical description of the cosmic X-ray background (CXRB) spectrum in the 1.5-200 keV energy band, obtained by combining the new measurement performed by the Swift X-ray telescope (XRT) with the recently published Swift burst alert telescope (BAT) measurement. A study of the cosmic variance in the XRT band (1.5-7 keV) is also presented. I find that the expected cosmic variance (expected from LogN-LogS) scales as {omega}{sup -0.3}(where {omega} is the surveyed area) in very good agreement with XRT data.

Moretti, A. [INAF-Osservatorio Astronomico di Brera v. E. Bianchi 46 23807 Merate (Italy)

2009-05-11T23:59:59.000Z

448

Viscosity in X-ray clusters: Braginskii over 5  

E-Print Network (OSTI)

We argue that it is currently impossible to simulate X-ray clusters using correct equations, because even the MHD description is not applicable. But since fluid simulations actually reproduce observations quite well, one may try to improve the fluid codes by including molecular transport of heat and momentum. We calculate the effective molecular viscosity for the simplest model of magnetic field and obtain 1/5 of the Braginskii value, similar to 1/3 of Spitzer for the heat conduction. This is large enough to noticeably damp the X-ray cluster turbulence.

A. Gruzinov

2006-11-07T23:59:59.000Z

449

X-ray instrumentation for the photon factory  

SciTech Connect

The Photon Factory is one of the world's largest synchroton radiation light sources, the beam lines of which supply intense sources of vacuum UV, soft and hard X-rays. About 30 measuring instruments have been purpose-built, and this book describes the development and construction of the X-ray instrumentation. Given the multifunctional nature of the Photon Factory, it may be expected that the instrumentation serving it fulfills a variety of purposes including: reflection imaging systems; diffraction grating fabrication; monochromators; polarizers; analyzers; detectors; data collection systems; cameras; and goniometers.

Hosoya, S.; Iitaka, Y.; Hashizume, H.

1987-01-01T23:59:59.000Z

450

Confusion of Diffuse Objects in the X-ray Sky  

E-Print Network (OSTI)

Most of the baryons in the present-day universe are thought to reside in intergalactic space at temperatures of 10^5-10^7 K. X-ray emission from these baryons contributes a modest (~10%) fraction of the ~ 1 keV background whose prominence within the large-scale cosmic web depends on the amount of non-gravitational energy injected into intergalactic space by supernovae and AGNs. Here we show that the virialized regions of groups and clusters cover over a third of the sky, creating a source-confusion problem that may hinder X-ray searches for individual intercluster filaments and contaminate observations of distant groups.

G. Mark Voit; August E. Evrard; Greg L. Bryan

2000-12-08T23:59:59.000Z

451

Cooling for a rotating anode X-ray tube  

DOE Patents (OSTI)

A method and apparatus for cooling a rotating anode X-ray tube. An electromagnetic motor is provided to rotate an X-ray anode with cooling passages in the anode. These cooling passages are coupled to a cooling structure located adjacent the electromagnetic motor. A liquid metal fills the passages of the cooling structure and electrical power is provided to the motor to rotate the anode and generate a rotating magnetic field which moves the liquid metal through the cooling passages and cooling structure.

Smither, Robert K. (Hinsdale, IL)

1998-01-01T23:59:59.000Z

452

Optimized Volumetric Scanning for X-Ray Array Sources  

SciTech Connect

Non-destructive evaluation (NDE) is the science and technology of determining non-invasively the internal structure of manufactured parts, objects, and materials. NDE application areas include medicine, industrial manufacturing, military, homeland security, and airport luggage screening. X-ray measurement systems are most widely used because of their ability to image through a wide range of material densities (from human tissue in medical applications to the dense materials of weapon components). Traditional x-ray systems involve a single source and detector system that rotate and/or translate about the object under evaluation. At each angular location, the source projects x-rays through the object. The rays undergo attenuation proportional to the density of the object's constitutive material. The detector records a measure of the attenuation. Mathematical algorithms are used to invert the forward attenuated ray projection process to form images of the object. This is known as computed tomography (CT). In recent years, the single-source x-ray NDE systems have been generalized to arrays of x-ray sources. Array sources permit multiple views of the object with fewer rotations and translations of the source/detector system. The spatially diverse nature of x-ray array sources has the potential of reducing data collection time, reducing imaging artifacts, and increasing the resolution of the resultant images. Most of the existing CT algorithms were not derived from array source models with a spatially diverse set of viewing perspectives. Single-source x-ray CT data collection, processing, and imaging methods and algorithms are not applicable when the source location is expanded from one dimension (a rotating and/or translating point source) to two (a rotating and/or translating array). They must be reformulated. The goal of this project is to determine the applicability of x-ray array sources to problems of interest to LLNL and its customers. It is believed array source data collection will be faster while yielding higher resolution reconstructions with fewer artifacts. There are three tasks in the research: (1) Develop forward array source analytic and computational models; (2) Research and develop array source reconstruction algorithms; and (3) Perform experiments.

Lehman, S K; Foudray, A M; Wang, A; Kallman, J S; Martz, H

2009-09-29T23:59:59.000Z

453

High intensity line source for x-ray spectrometer calibration  

SciTech Connect

A high intensity electron-impact x-ray source using a one-dimensional Pierce lens has been built for the purpose of calibrating a bent crystal x-ray spectrometer. This source focuses up to 100 mA of 20-keV electrons to a line on a liquid-cooled anode. The line (which can serve as a virtual slit for the spectrometer) measures approximately 800 ..mu.. x 2 cm. The source is portable and therefore adaptable to numerous types of spectrometer applications. One particular application, the calibration of a high resolution (r = 10/sup 4/) time-resolved cyrstal spectrometer, will be discussed in detail.

Thoe, R.S.

1986-06-01T23:59:59.000Z

454

High resolution collimator system for X-ray detector  

DOE Patents (OSTI)

High resolution in an X-ray computerized tomography (CT) inspection system is achieved by using a collimator/detector combination to limit the beam width of the X-ray beam incident on a detector element to the desired resolution width. In a detector such as a high pressure Xenon detector array, a narrow tapered collimator is provided above a wide detector element. The collimator slits have any desired width, as small as a few mils at the top, the slit width is easily controlled, and they are fabricated on standard machines. The slit length determines the slice thickness of the CT image.

Eberhard, Jeffrey W. (Schenectady, NY); Cain, Dallas E. (Scotia, NY)

1987-01-01T23:59:59.000Z

455

Method and apparatus for producing sharp chromatic x-ray images of x-ray emitting objects  

SciTech Connect

Method and apparatus for producing sharp, chromatic, magnified images of X-ray emitting objects, are provided. The apparatus, which constitutes an X-ray microscope or telescope, comprises a connected collection of Bragg reflecting planes, comprised of either a bent crystal or a synthetic multilayer structure, disposed on and adjacent to a locus determined by a spherical surface. The individual Bragg planes are spatially oriented to Bragg reflect radiation from the object location toward the image location. This is accomplished by making the Bragg planes spatially coincident with the surfaces of either a nested series of prolate ellipsoids of revolution, or a nested series of spheres. The spacing between the Bragg reflecting planes can be tailored to control the wavelengths and the amount of the X-radiation that is Bragg reflected to form the X-ray image. 7 figs.

Thoe, R.S.

1990-01-09T23:59:59.000Z

456

An experimental measurement of metal multilayer x-ray reflectivity degradation due to intense x-ray flux  

SciTech Connect

The degradation of the x-ray reflection characteristics of metal multilayer Bragg diffractors due to intense x-ray flux was investigated. The Z-pinch plasma produced by PROTO II of Sandia National Laboratories, Albuquerque, New Mexico, was used as the source. The plasma generated total x-ray yields of as much as 40 kJ with up to 15 kJ in the neon hydrogen- and helium-like resonance lines in nominal 20-ns pulses. Molybdenum-carbon, palladium-carbon, and tungsten-carbon metal multilayers were placed at 15 and 150 cm from the plasma center. The multilayers were at nominal angles of 5/sup 0/ and 10/sup 0/ to diffract the neon resonance lines. The time-integrated x-ray reflection of the metal multilayers was monitored by x-ray film. A fluorescer-fiber optic-visible streak camera detector system was then used to monitor the time-resolved x-ray reflection characteristics of 135 A- 2d tungsten-carbon multilayers. A large specular component in the reflectivity prevented determination of the rocking curve of the multilayer. For a neon implosion onto a vanadium-doped polyacrylic acid foam target shot, detailed modeling was attempted. The spectral flux was determined with data from 5 XRD channels and deconvolved using the code SHAZAM. The observed decay in reflectivity was assumed to correspond to the melting of the first tungsten layer. A ''conduction factor'' of 82 was required to manipulate the heat loading of the first tungsten layer such that the time of melting corresponded to the observed decay. The power at destruction was 141 MW/cm/sup 2/ and the integrated energy at destruction was 2.0 J/cm/sup 2/. 82 refs., 66 figs., 10 tabs.

Hockaday, M.Y.P.

1987-06-01T23:59:59.000Z

457

Modification of the TASMIP x-ray spectral model for the simulation of microfocus x-ray sources  

SciTech Connect

Purpose: The availability of accurate and simple models for the estimation of x-ray spectra is of great importance for system simulation, optimization, or inclusion of photon energy information into data processing. There is a variety of publicly available tools for estimation of x-ray spectra in radiology and mammography. However, most of these models cannot be used directly for modeling microfocus x-ray sources due to differences in inherent filtration, energy range and/or anode material. For this reason the authors propose in this work a new model for the simulation of microfocus spectra based on existing models for mammography and radiology, modified to compensate for the effects of inherent filtration and energy range. Methods: The authors used the radiology and mammography versions of an existing empirical model [tungsten anode spectral model interpolating polynomials (TASMIP)] as the basis of the microfocus model. First, the authors estimated the inherent filtration included in the radiology model by comparing the shape of the spectra with spectra from the mammography model. Afterwards, the authors built a unified spectra dataset by combining both models and, finally, they estimated the parameters of the new version of TASMIP for microfocus sources by calibrating against experimental exposure data from a microfocus x-ray source. The model was validated by comparing estimated and experimental exposure and attenuation data for different attenuating materials and x-ray beam peak energy values, using two different x-ray tubes. Results: Inherent filtration for the radiology spectra from TASMIP was found to be equivalent to 1.68 mm Al, as compared to spectra obtained from the mammography model. To match the experimentally measured exposure data the combined dataset required to apply a negative filtration of about 0.21 mm Al and an anode roughness of 0.003 mm W. The validation of the model against real acquired data showed errors in exposure and attenuation in line with those reported for other models for radiology or mammography. Conclusions: A new version of the TASMIP model for the estimation of x-ray spectra in microfocus x-ray sources has been developed and validated experimentally. Similarly to other versions of TASMIP, the estimation of spectra is very simple, involving only the evaluation of polynomial expressions.

Sisniega, A.; Vaquero, J. J., E-mail: juanjose.vaquero@uc3m.es [Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Madrid ES28911 (Spain); Instituto de Investigación Sanitaria Gregorio Marañón, Madrid ES28007 (Spain); Desco, M. [Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Madrid ES28911 (Spain) [Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Madrid ES28911 (Spain); Instituto de Investigación Sanitaria Gregorio Marañón, Madrid ES28007 (Spain); Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid ES28029 (Spain)

2014-01-15T23:59:59.000Z

458

THE X-RAY BINARY POPULATION IN M33. II. X-RAY SPECTRA AND VARIABILITY H.-J. Grimm, J. McDowell, A. Zezas, D.-W. Kim, and G. Fabbiano  

E-Print Network (OSTI)

THE X-RAY BINARY POPULATION IN M33. II. X-RAY SPECTRA AND VARIABILITY H.-J. Grimm, J. McDowell, A the X-ray spectra and X-ray spectral variability of compact X-ray sources for 3 Chandra observations observations shows that X-ray absorption values are consistent with Galactic X-ray binaries and most sources

Kim, Dong-Woo

459

The SIMBOL-X hard X-ray mission  

Science Journals Connector (OSTI)

SIMBOL-X is a hard X-ray mission ... jointly carried out by CNES and ASI. SIMBOL-X makes uses of a long (in ... non focusing techniques used so far. The SIMBOL-X revolutionary instrumental capabilities will allow...

Giovanni Pareschi; Philippe Ferrando

2005-12-01T23:59:59.000Z

460

The SIMBOL-X hard X-ray mission  

Science Journals Connector (OSTI)

SIMBOL-X is a hard X-ray mission ... jointly carried out by CNES and ASI. SIMBOL-X makes uses of a long (in ... non focusing techniques used so far. The SIMBOL-X revolutionary instrumental capabilities will allow...

Giovanni Pareschi; Philippe Ferrando

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Data needs for X-ray astronomy satellites  

SciTech Connect

I review the current status of atomic data for X-ray astronomy satellites. This includes some of the astrophysical issues which can be addressed, current modeling and analysis techniques, computational tools, the limitations imposed by currently available atomic data, and the validity of standard assumptions. I also discuss the future: challenges associated with future missions and goals for atomic data collection.

Kallman, T. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2013-07-11T23:59:59.000Z

462

THE SWIFT/BAT HARD X-RAY TRANSIENT MONITOR  

SciTech Connect

The Swift/Burst Alert Telescope (BAT) hard X-ray transient monitor provides near real-time coverage of the X-ray sky in the energy range 15-50 keV. The BAT observes 88% of the sky each day with a detection sensitivity of 5.3 mCrab for a full-day observation and a time resolution as fine as 64 s. The three main purposes of the monitor are (1) the discovery of new transient X-ray sources, (2) the detection of outbursts or other changes in the flux of known X-ray sources, and (3) the generation of light curves of more than 900 sources spanning over eight years. The primary interface for the BAT transient monitor is a public Web site. Between 2005 February 12 and 2013 April 30, 245 sources have been detected in the monitor, 146 of them persistent and 99 detected only in outburst. Among these sources, 17 were previously unknown and were discovered in the transient monitor. In this paper, we discuss the methodology and the data processing and filtering for the BAT transient monitor and review its sensitivity and exposure. We provide a summary of the source detections and classify them according to the variability of their light curves. Finally, we review all new BAT monitor discoveries. For the new sources that are previously unpublished, we present basic data analysis and interpretations.

Krimm, H. A.; Holland, S. T.; Corbet, R. H. D.; Pearlman, A. B.; Baumgartner, W. H.; Cummings, J. R. [Center for Research and Exploration in Space Science and Technology (CRESST) and NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Romano, P. [INAF, Istituto di Astrofisica Spaziale e Fisica Cosmica, Via U. La Malfa 153, I-90146 Palermo (Italy); Kennea, J. A. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Bloom, J. S. [Department of Astronomy, University of California, Berkeley, Berkeley, CA 94720-3411 (United States); Barthelmy, S. D.; Gehrels, N.; Lien, A. Y.; Markwardt, C. B.; Ukwatta, T. N. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Palmer, D. M. [Los Alamos National Laboratory, B244, Los Alamos, NM 87545 (United States); Sakamoto, T. [Department of Physics and Mathematics, College of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara-shi, Kanagawa 252-5258 (Japan); Stamatikos, M. [Department of Physics and Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, OH 43210 (United States)

2013-11-01T23:59:59.000Z

463

Search for X-ray occultations in active galactic nuclei  

Science Journals Connector (OSTI)

......The simplest and most effective (in terms of source coverage due to the intervening...all the existing XMM observations do not enter in our sample since they last less than...interpretation of HR time variability in terms of X-ray source occultations by BLR-like......

G. Torricelli-Ciamponi; P. Pietrini; G. Risaliti; M. Salvati

2014-01-01T23:59:59.000Z

464

DEDUCING ELECTRON PROPERTIES FROM HARD X-RAY OBSERVATIONS  

E-Print Network (OSTI)

of the accelerated electron distribution. Keywords: Sun: flares; Sun: X-rays; Sun: acceleration; Sun: energetic distribution 31 4.5 Low-energy cutoffs in the electron distribution 32 4.6 Temperature distribution of thermal-ray emission process(es) in question with the electron distribution function, which is in turn a function

Piana, Michele

465

ROSAT X-ray observations of 3CRR radio sources  

Science Journals Connector (OSTI)

......al. 1995). The available X-ray data are unfortunately not good enough to test whether 3C 288 lies in a cooling flow, a suggested...Leahy J. P. , Bridle A. H., Strom R. G.. (1998, Internet WWW page, at URL: http://www:jb:man:ac:uk/atlas......

M. J. Hardcastle; D. M. Worrall

1999-11-11T23:59:59.000Z

466

Soft x-ray laser microscope. Final report  

SciTech Connect

The program consisted of two phases (Phase I and Phase II). The goal of the Phase I (first year program) was to design and construct the Soft X-ray Laser Contact Microscope. Such microscope was constructed and adapted to PPL`s 18.2nm soft X-ray Laser (SXL), which in turn was modified and prepared for microscopy experiments. Investigation of the photoresist response to 18.2nm laser radiation and transmissivity of 0.1m thick silicion-nitride (Si{sub 3}N{sub 4}) windows were important initial works. The goal of the first year of Phase II was to construct X-ray contact microscope in combination with existing optical phase microscope, already used by biologists. In the second year of Phase II study of dehydrated Horeseshoe Crab and Hela cancer cells were performed with COXRALM. Also during Phase II, the Imaging X-Ray Laser Microscope (IXRALM) was designed and constructed. This paper describes the development of each of the microscopes and their application for research.

Suckewer, P.I.

1990-10-01T23:59:59.000Z

467

Radioactivity and X-rays Applications and health effects  

E-Print Network (OSTI)

as the release of radioactivity from reactor accidents and fallout from nuclear explosions in the atmosphereRadioactivity and X-rays Applications and health effects by Thormod Henriksen #12;Preface ­ 7 Chapter 2. What is radioactivity page 8 ­ 27 Chapter 3. Radioactive decay laws page 28 ­ 35

Sahay, Sundeep

468

The Evolution of Coronal X-ray Emission  

E-Print Network (OSTI)

as a hydrogen burning star. Rocks were present in the solar system at 1 Myr, the giant planets formed within 10 flares, coronal mass ejections etc. interact(ed) with planetary systems. The properties of the early Sun out (i.e. photoionisation/photodissociation can change chemistry, X-ray/EUV radiation can heat upper

469

Vanadium-pumped titanium x-ray laser  

DOE Patents (OSTI)

A resonantly photo-pumped x-ray laser is formed of a vanadium and titanium foil combination that is driven by two beams of intense line focused optical laser radiation. Ground state neon-like titanium ions are resonantly photo-pumped by line emission from fluorine-like vanadium ions. 4 figs.

Nilsen, J.

1992-05-26T23:59:59.000Z

470

Vanadium-pumped titanium x-ray laser  

DOE Patents (OSTI)

A resonantly photo-pumped x-ray laser (10) is formed of a vanadium (12) and titanium (14) foil combination (16) that is driven by two beams (18, 20) of intense line focused (22, 24) optical laser radiation. Ground state neon-like titanium ions (34) are resonantly photo-pumped by line emission from fluorine-like vanadium ions (32).

Nilsen, Joseph (Livermore, CA)

1992-01-01T23:59:59.000Z

471

Population synthesis for symbiotic X-ray binaries  

Science Journals Connector (OSTI)

......X-ray luminosities (mass-accretion rates...models with a low wind velocity (v w = 1/2v esc...Figure 6 Grey-scale maps of the distributions...period P s versus mass-accretion rate...greatly depends on the wind velocity. NSs in 4U 1954......

G.-L. Lü; C.-H. Zhu; K. A. Postnov; L. R. Yungelson; A. G. Kuranov; N. Wang

2012-08-11T23:59:59.000Z

472

Generating coherent broadband continuum soft-x-ray radiation by  

E-Print Network (OSTI)

Generating coherent broadband continuum soft-x-ray radiation by attosecond ionization gating Thomas as the driver for high-harmonic generation that has a cosine-like electric field stabilized with respect the generation of broadband and tunable attosecond pulses. Instead of fixing the carrier-envelope phase

Neumark, Daniel M.

473

X-ray emission from clusters of galaxies  

SciTech Connect

Some X-ray spectral observations of approximately 30 clusters of galaxies from HEAO-1 are summarized. There exists strong correlations between X-ray luminosity, L(x), and temperature kT in the form L(x)alphaT to the 2.3 power. This result combined with the L(x) central galaxy density relation and the virial theorem indicates that the core radius of the gas should be roughly independent of L(x) or KT and that more luminous clusters have a greater fraction of their virial mass in gas. The poor correlation of KT and optical velocity dispersion seems to indicate that clusters have a variety of equations of state. There is poor agreement between X-ray imaging observations and optical and X-ray spectral measures of the polytropic index. Most clusters show Fe emission lines with a strong indication that they all have roughly 1/2 solar abundance. The evidence for cooling in the cores of several clusters is discussed based on spectral observations with the Einstein solid state spectrometer.

Mushotzky, R.F.

1983-05-01T23:59:59.000Z

474

Observation of correlated X-ray scattering at atomic resolution  

Science Journals Connector (OSTI)

...order, such as proteins in solution...to study such disordered matter. The...X-rays from an ensemble of identical...signal from an ensemble in three dimensions...experiments on disordered ensembles-such as proteins in solution-may...

2014-01-01T23:59:59.000Z

475

Modeling Structural Heterogeneity in Proteins From X-Ray Data  

E-Print Network (OSTI)

Modeling Structural Heterogeneity in Proteins From X-Ray Data Ankur Dhanik1 , Henry van den Bedem2: In a crystallographic experiment, a protein is precipitated to obtain a crystalline sample (crystal) containing many determination and density calculation. The protein conformation is modeled by placing the atoms in 3-D space

Pratt, Vaughan

476

Single atom identification by energy dispersive x-ray spectroscopy  

SciTech Connect

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

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

2012-04-09T23:59:59.000Z

477

Transient x-ray absorption spectroscopy of hydrated halogen atom  

E-Print Network (OSTI)

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

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

2008-02-11T23:59:59.000Z

478

X-rays at Solid-Liquid Surfaces  

SciTech Connect

Solid-liquid interfaces play an important role in many areas of current and future technologies, and in our biosphere. They play a key role in the development of nanofluidics and nanotribology, which sensitively depend on our knowledge of the microscopic structures and phenomena at the solid-liquid interface. The detailed understanding of how a fluid meets a wall is also a theoretical challenge. In particular, the phenomena at repulsive walls are of interest, since they affect many different phenomena, such as water-repellent surfaces or the role of the hydrophobic interaction in protein folding. Recent x-ray reflectivity studies of various solid-liquid interfaces have disclosed rather intriguiing phenomena, which will be discussed in this lecture: premelting of ice in contact with silica; liquid Pb in contact with Si; water in contact with hydrophobic surfaces. These experiments, carried out with high-energy x-ray microbeams, reveal detailed insight into the liquid density profile closest to the wall. A detailed insight into atomistic phenomena at solid-liquid interfaces is also a prerequisite in the microscopic control of electrochemical reactions at interfaces. Recent x-ray studies show the enormous future potential of such non-destructive analytical tools for the in situ observation of (electro-)chemical surface reactions. This lecture will review recent x-ray experiments on solid-liquid interfaces.

Dosch, Helmut (Max Planck Institute for Metals Research) [Max Planck Institute for Metals Research

2007-05-02T23:59:59.000Z

479

High-resolution imaging with soft x-rays  

Science Journals Connector (OSTI)

...concave surface of the larger mirror, where a second reflection...the surface of the spherical mirrors is the main limitation, and...achievable and will permit a Schwarzschild x-ray microscope to have...be able to test spherical mirrors to within 6 angstroms by next...

AL Robinson

1982-01-08T23:59:59.000Z

480

X-ray Emission from Thunderstorms and Lightning  

ScienceCinema (OSTI)

How lightning is initiated in the relatively low electric fields inside thunderclouds and how it can then propagate for tens of kilometers through virgin air are two of the great unsolved problems in the atmospheric sciences.  Until very recently it was believed that lightning was entirely a conventional discharge, involving only low-energy (a few eV) electrons.  This picture changed completely a few years ago with the discovery of intense x-ray emission from both natural cloud-to-ground lightning and rocket-triggered lightning.  This energetic emission cannot be produced by a conventional discharge, and so the presence of x-rays strongly implies that runaway breakdown plays a role in lightning processes.  During runaway breakdown, electrons are accelerated through air to nearly the speed of light by strong electric fields.  These runaway electrons then emit bremsstrahlung x-rays and gamma-rays during collisions with air.  Indeed, the x-ray and gamma-ray emission produced by runaway breakdown near the tops of thunderstorms is bright enough to be seen from outer space, 600 km away.  As a result, the physics used for decades to describe thunderstorm electrification and lightning discharges is incomplete and needs to be revisited. 

Joseph Dwyer

2010-01-08T23:59:59.000Z

Note: This page contains sample records for the topic "ambient-pressure x-ray photoelectron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

X-ray ferromagnetic resonance spectroscopy and S. Rusponi  

E-Print Network (OSTI)

-coupled multilayers,1,2,11,12 as well as current-induced magnetization excitations in spin-valve structures.13,14 Very at GHz frequencies. XMCD is defined as the dependence of the x-ray absorp- tion coefficient

Brune, Harald

482

Double K-Vacancy Production by X-Ray Photoionization  

E-Print Network (OSTI)

Double K-Vacancy Production by X-Ray Photoionization S. H. Southworth£ , R. W. Dunford£ , E. P Photon Source. Double K-vacancy production in Ne was observed by recording the KK-KLL Auger. For Mo, double K-vacancy production was observed by recording the K fluorescence hypersatellite

483

Vacuum breakdown mechanisms, and X-ray pulses in accelerators  

Science Journals Connector (OSTI)

During the conditioning of evacuated accelerator tubes, groups of discrete X-ray signals with apparent energies of greater than 300 keV are observed. A mechanism to explain the X-ray emission is proposed in terms of a series of transient vacuum arc discharges. A review is given of vacuum breakdown mechanisms, and of the most likely processes occurring in accelerator tubes during the conditioning process. In the case of the vacuum accelerator tube, there is initially no gaseous medium, but the applied voltage of 30 kV between the tube electrodes is sufficient to lead to the formation of a vacuum arc if there are fine whiskers, impurities, or accelerated dust particles present. Such a vacuum discharge will have a very short life (?1 ?s), as the current of the arc will cause the collapse of the electrode voltage which is maintained by a small current through 600 M? resistors. During the discharge, electrons will escape into the accelerator tube, and fall through several sections to be finally arrested, producing the discrete X-ray signals. The vacuum arc will release charged molten droplets of anode material into the high-field region; after some delay, these droplets will trigger further arcs in different sections of the tube. The triggered arcs will be at the inner edges of the electrode where the droplets hit the electrode, and where electrons are most readily released into the accelerator tube. Thus a whole series of high energy X-ray signals are observed.

R Morrow; D.C Weisser

1996-01-01T23:59:59.000Z

484

Beyond 3-D X-ray Imaging: Methodology Development and Applications in  

NLE Websites -- All DOE Office Websites (Extended Search)

Beyond 3-D X-ray Imaging: Methodology Development and Applications in Beyond 3-D X-ray Imaging: Methodology Development and Applications in Material Science Thursday, September 6, 2012 - 10:45am SLAC, Bldg. 137, Room 226 Yijin Liu Seminar There was a revolutionary development of X-ray imaging over the past few decades. The most substantial advancements in this field are closely related to the availability of the new generation of X-ray sources and the advanced X-ray optics. The advanced X-ray Optics along with novel methodology has made it possible to extract information that is related to different interactions between the X-rays and the specimen at very fine spatial resolution. The energy tunability of the X-rays has made it possible to combine the energy scan with imaging technique. And the brilliance of the X-ray source has made it practical for many sophisticated

485

Models for X-Ray Emission from Isolated Pulsars  

E-Print Network (OSTI)

A model is proposed for the observed combination of power-law and thermal emission of keV X-rays from rotationally powered pulsars. For gamma-ray pulsars with accelerators very many stellar radii above the neutron star surface, 100 MeV curvature gamma-rays from $e^{-}$ or $e^{+}$ flowing starward out of such accelerators are converted to electron-positron pairs on closed field lines all around the star. These pairs strongly affect X-ray emission from near the star in two ways. (1) The pairs are a source of synchrotron emission immediately following their creation in regions where $B \\sim 10^{10}$ G. This emission, in the photon energy range 0.1 keV $\\lesssim E_{X} \\lesssim$ 5 MeV, has a power-law spectrum with energy index 0.5 and X-ray luminosity that depends on the backflow current, and is typically $\\sim 10^{33}$ \\lum. (2) The pairs ultimately form a cyclotron resonance ``blanket'' surrounding the star except for two holes along the open field line bundles which pass through it. In such a blanket the gravitational pull on electron-positron pairs toward the star is balanced by the hugely amplified push of outflowing surface emitted X-rays wherever cyclotron resonance occurs. Because of it the neutron star is surrounded by a leaky ``hohlraum'' of hot blackbody radiation with two small holes, which prevents direct X-ray observation of a heated polar cap of a gamma-ray pulsar. Weakly spin-modulated radiation from the blanket together with more strongly spin-modulated radiation from the holes through it would then dominate observed low energy (0.1--10 keV) emission. For non-gamma-ray pulsars, in which no such accelerators with their accompanying extreme relativistic backflow toward the star are ...

F. Y. -H. Wang; M. Ruderman; J. P. Halpern; T. Zhu

1997-11-24T23:59:59.000Z

486

Time dependence of X-ray polarizability of a crystal induced by an intense femtosecond X-ray pulse  

Science Journals Connector (OSTI)

The time evolution of the electron density and the resulting time dependence of the X-ray polarizability of a crystal irradiated by highly intense XFEL femtosecond pulses is investigated theoretically. Rate equations for bound electrons and the Boltzmann equation for the unbound electron gas are used in calculations.

Leonov, A.

2014-10-23T23:59:59.000Z

487

Reverse Monte Carlo analysis of the local order in liquid Ge{sub 0.15}Te{sub 0.85} alloys combining neutron scattering and x-ray absorption spectroscopy  

SciTech Connect

The structure of liquid Ge{sub 0.15}Te{sub 0.85} alloys that exhibit a density anomaly between 633 K and 733 K at ambient pressure was investigated using x-ray absorption spectroscopy at the Ge K edge. Using a reverse Monte Carlo method to combine the present results with neutron scattering data, we show that the volume contraction is associated with an increase of the first neighbor coordination number around both Ge and Te by about one atom. The coordination number of Ge increases from 3{+-}0.3 to 4.1{+-}0.3. These results support an interpretation of the density anomaly in terms of the same Peierls-like distortion mechanism acting in the liquid state and in the neighboring (pure Te and GeTe compound) phases.

Coulet, Marie-Vanessa; Testemale, Denis; Hazemann, Jean-Louis; Gaspard, Jean-Pierre; Bichara, Christophe [Laboratoire TECSEN, UMR 6122, CNRS-Universite Paul Cezanne, Campus de St Jerome, 13397 Marseille Cedex 20 (France); SNBL/ESRF, 6 rue Jules Horowitz, Boite Postale 220, 38043, Grenoble (France); Laboratoire de Cristallographie, 25 Avenue des Martyrs, Boite Postale 166, 38043 Grenoble (France) and European Synchroton Radiation Facility, 6 rue Jules Horowitz, Boite Postale 220, 38043 Grenoble (France); Physique de la Matiere Condensee, B5, Universite de Liege, B4000 Sart-Tilman (Belgium); Centre de Recherches en Matiere Condensee et Nanosciences-CNRS, Campus de Luminy, Case 913, F13288 Marseille (France)

2005-11-01T23:59:59.000Z

488